chore(frontend): remove unnecessary newline in overrides field of package.json

- Replaced `pytest.mark.skipif` with `pytest.skip` to better manage scenarios where `schemathesis` is not installed.
- Added a fallback test function to ensure explicit handling for missing dependencies.

.env.demo

@@ -0,0 +1,55 @@
+# Common settings
+PROJECT_NAME=App
+VERSION=1.0.0
+
+# Database settings
+POSTGRES_USER=postgres
+POSTGRES_PASSWORD=postgres
+POSTGRES_DB=app
+POSTGRES_HOST=db
+POSTGRES_PORT=5432
+DATABASE_URL=postgresql://postgres:postgres@db:5432/app
+
+# Backend settings
+BACKEND_PORT=8000
+# CRITICAL: Generate a secure SECRET_KEY for production!
+# Generate with: python -c 'import secrets; print(secrets.token_urlsafe(32))'
+# Must be at least 32 characters
+SECRET_KEY=demo_secret_key_for_testing_only_do_not_use_in_prod
+ENVIRONMENT=development
+DEMO_MODE=true
+DEBUG=true
+BACKEND_CORS_ORIGINS=["http://localhost:3000"]
+FIRST_SUPERUSER_EMAIL=admin@example.com
+# IMPORTANT: Use a strong password (min 12 chars, mixed case, digits)
+# Default weak passwords like 'Admin123' are rejected
+FIRST_SUPERUSER_PASSWORD=Admin123!
+
+# OAuth Configuration (Social Login)
+# Set OAUTH_ENABLED=true and configure at least one provider
+OAUTH_ENABLED=false
+OAUTH_AUTO_LINK_BY_EMAIL=true
+
+# Google OAuth (from Google Cloud Console > APIs & Services > Credentials)
+# https://console.cloud.google.com/apis/credentials
+# OAUTH_GOOGLE_CLIENT_ID=your-google-client-id.apps.googleusercontent.com
+# OAUTH_GOOGLE_CLIENT_SECRET=your-google-client-secret
+
+# GitHub OAuth (from GitHub > Settings > Developer settings > OAuth Apps)
+# https://github.com/settings/developers
+# OAUTH_GITHUB_CLIENT_ID=your-github-client-id
+# OAUTH_GITHUB_CLIENT_SECRET=your-github-client-secret
+
+# OAuth Provider Mode (Authorization Server for MCP/third-party clients)
+# Set OAUTH_PROVIDER_ENABLED=true to act as an OAuth 2.0 Authorization Server
+OAUTH_PROVIDER_ENABLED=true
+# IMPORTANT: Must be HTTPS in production!
+OAUTH_ISSUER=http://localhost:8000
+
+# Frontend settings
+FRONTEND_PORT=3000
+FRONTEND_URL=http://localhost:3000
+NEXT_PUBLIC_API_URL=http://localhost:8000
+NEXT_PUBLIC_API_BASE_URL=http://localhost:8000
+NEXT_PUBLIC_APP_URL=http://localhost:3000
+NODE_ENV=development

.env.template

@@ -17,6 +17,7 @@ BACKEND_PORT=8000
 # Must be at least 32 characters
 SECRET_KEY=your_secret_key_here_REPLACE_WITH_GENERATED_KEY_32_CHARS_MIN
 ENVIRONMENT=development
+DEMO_MODE=false
 DEBUG=true
 BACKEND_CORS_ORIGINS=["http://localhost:3000"]
 FIRST_SUPERUSER_EMAIL=admin@example.com
@@ -24,7 +25,31 @@ FIRST_SUPERUSER_EMAIL=admin@example.com
 # Default weak passwords like 'Admin123' are rejected
 FIRST_SUPERUSER_PASSWORD=YourStrongPassword123!
 
+# OAuth Configuration (Social Login)
+# Set OAUTH_ENABLED=true and configure at least one provider
+OAUTH_ENABLED=false
+OAUTH_AUTO_LINK_BY_EMAIL=true
+
+# Google OAuth (from Google Cloud Console > APIs & Services > Credentials)
+# https://console.cloud.google.com/apis/credentials
+# OAUTH_GOOGLE_CLIENT_ID=your-google-client-id.apps.googleusercontent.com
+# OAUTH_GOOGLE_CLIENT_SECRET=your-google-client-secret
+
+# GitHub OAuth (from GitHub > Settings > Developer settings > OAuth Apps)
+# https://github.com/settings/developers
+# OAUTH_GITHUB_CLIENT_ID=your-github-client-id
+# OAUTH_GITHUB_CLIENT_SECRET=your-github-client-secret
+
+# OAuth Provider Mode (Authorization Server for MCP/third-party clients)
+# Set OAUTH_PROVIDER_ENABLED=true to act as an OAuth 2.0 Authorization Server
+OAUTH_PROVIDER_ENABLED=false
+# IMPORTANT: Must be HTTPS in production!
+OAUTH_ISSUER=http://localhost:8000
+
 # Frontend settings
 FRONTEND_PORT=3000
+FRONTEND_URL=http://localhost:3000
 NEXT_PUBLIC_API_URL=http://localhost:8000
+NEXT_PUBLIC_API_BASE_URL=http://localhost:8000
+NEXT_PUBLIC_APP_URL=http://localhost:3000
 NODE_ENV=development

.github/workflows/README.md

@@ -41,7 +41,7 @@ To enable CI/CD workflows:
 - Runs on: Push to main/develop, PRs affecting frontend code
 - Tests: Frontend unit tests (Jest)
 - Coverage: Uploads to Codecov
-- Fast: Uses npm cache
+- Fast: Uses bun cache
 
 ### `e2e-tests.yml`
 - Runs on: All pushes and PRs

.github/workflows/backend-e2e-tests.yml.template

@@ -0,0 +1,77 @@
+# Backend E2E Tests CI Pipeline
+#
+# Runs end-to-end tests with real PostgreSQL via Testcontainers
+# and validates API contracts with Schemathesis.
+#
+# To enable: Rename this file to backend-e2e-tests.yml
+
+name: Backend E2E Tests
+
+on:
+  push:
+    branches: [main, develop]
+    paths:
+      - 'backend/**'
+      - '.github/workflows/backend-e2e-tests.yml'
+  pull_request:
+    branches: [main, develop]
+    paths:
+      - 'backend/**'
+  workflow_dispatch:
+
+jobs:
+  e2e-tests:
+    runs-on: ubuntu-latest
+    # E2E test failures don't block merge - they're advisory
+    continue-on-error: true
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@v4
+        with:
+          version: "latest"
+
+      - name: Cache uv dependencies
+        uses: actions/cache@v4
+        with:
+          path: ~/.cache/uv
+          key: uv-${{ runner.os }}-${{ hashFiles('backend/uv.lock') }}
+          restore-keys: |
+            uv-${{ runner.os }}-
+
+      - name: Install dependencies (with E2E)
+        working-directory: ./backend
+        run: uv sync --extra dev --extra e2e
+
+      - name: Check Docker availability
+        id: docker-check
+        run: |
+          if docker info > /dev/null 2>&1; then
+            echo "available=true" >> $GITHUB_OUTPUT
+            echo "Docker is available"
+          else
+            echo "available=false" >> $GITHUB_OUTPUT
+            echo "::warning::Docker not available - E2E tests will be skipped"
+          fi
+
+      - name: Run E2E tests
+        if: steps.docker-check.outputs.available == 'true'
+        working-directory: ./backend
+        env:
+          IS_TEST: "True"
+          SECRET_KEY: "e2e-test-secret-key-minimum-32-characters-long"
+          PYTHONPATH: "."
+        run: |
+          uv run pytest tests/e2e/ -v --tb=short
+
+      - name: E2E tests skipped
+        if: steps.docker-check.outputs.available != 'true'
+        run: echo "E2E tests were skipped due to Docker unavailability"

.gitignore

@@ -27,6 +27,10 @@ coverage
 # nyc test coverage
 .nyc_output
 
+# Playwright authentication state (contains test auth tokens)
+frontend/e2e/.auth/
+**/playwright/.auth/
+
 # Grunt intermediate storage (https://gruntjs.com/creating-plugins#storing-task-files)
 .grunt
 
@@ -183,7 +187,7 @@ coverage.xml
 .hypothesis/
 .pytest_cache/
 cover/
-
+backend/.benchmarks
 # Translations
 *.mo
 *.pot
@@ -264,6 +268,7 @@ celerybeat.pid
 .env
 .env.*
 !.env.template
+!.env.demo
 .venv
 env/
 venv/

AGENTS.md

@@ -0,0 +1,315 @@
+# AGENTS.md
+
+AI coding assistant context for FastAPI + Next.js Full-Stack Template.
+
+## Quick Start
+
+```bash
+# Backend (Python with uv)
+cd backend
+make install-dev              # Install dependencies
+make test                     # Run tests
+uv run uvicorn app.main:app --reload  # Start dev server
+
+# Frontend (Node.js)
+cd frontend
+bun install                   # Install dependencies
+bun run dev                   # Start dev server
+bun run generate:api          # Generate API client from OpenAPI
+bun run test:e2e              # Run E2E tests
+```
+
+**Access points:**
+- Frontend: **http://localhost:3000**
+- Backend API: **http://localhost:8000**
+- API Docs: **http://localhost:8000/docs**
+
+Default superuser (change in production):
+- Email: `admin@example.com`
+- Password: `admin123`
+
+## Project Architecture
+
+**Full-stack TypeScript/Python application:**
+
+```
+├── backend/                 # FastAPI backend
+│   ├── app/
+│   │   ├── api/            # API routes (auth, users, organizations, admin)
+│   │   ├── core/           # Core functionality (auth, config, database)
+│   │   ├── repositories/   # Repository pattern (database operations)
+│   │   ├── models/         # SQLAlchemy ORM models
+│   │   ├── schemas/        # Pydantic request/response schemas
+│   │   ├── services/       # Business logic layer
+│   │   └── utils/          # Utilities (security, device detection)
+│   ├── tests/              # 96% coverage, 987 tests
+│   └── alembic/            # Database migrations
+│
+└── frontend/               # Next.js 16 frontend
+    ├── src/
+    │   ├── app/           # App Router pages (Next.js 16)
+    │   ├── components/    # React components
+    │   ├── lib/
+    │   │   ├── api/       # Auto-generated API client
+    │   │   └── stores/    # Zustand state management
+    │   └── hooks/         # Custom React hooks
+    └── e2e/               # Playwright E2E tests (56 passing)
+```
+
+## Critical Implementation Notes
+
+### Authentication Flow
+- **JWT-based**: Access tokens (15 min) + refresh tokens (7 days)
+- **OAuth/Social Login**: Google and GitHub with PKCE support
+- **Session tracking**: Database-backed with device info, IP, user agent
+- **Token refresh**: Validates JTI in database, not just JWT signature
+- **Authorization**: FastAPI dependencies in `api/dependencies/auth.py`
+  - `get_current_user`: Requires valid access token
+  - `get_current_active_user`: Requires active account
+  - `get_optional_current_user`: Accepts authenticated or anonymous
+  - `get_current_superuser`: Requires superuser flag
+
+### OAuth Provider Mode (MCP Integration)
+Full OAuth 2.0 Authorization Server for MCP (Model Context Protocol) clients:
+- **Authorization Code Flow with PKCE**: RFC 7636 compliant
+- **JWT access tokens**: Self-contained, no DB lookup required
+- **Opaque refresh tokens**: Stored hashed in database, supports rotation
+- **Token introspection**: RFC 7662 compliant endpoint
+- **Token revocation**: RFC 7009 compliant endpoint
+- **Server metadata**: RFC 8414 compliant discovery endpoint
+- **Consent management**: User can review and revoke app permissions
+
+**API endpoints:**
+- `GET /.well-known/oauth-authorization-server` - Server metadata
+- `GET /oauth/provider/authorize` - Authorization endpoint
+- `POST /oauth/provider/authorize/consent` - Consent submission
+- `POST /oauth/provider/token` - Token endpoint
+- `POST /oauth/provider/revoke` - Token revocation
+- `POST /oauth/provider/introspect` - Token introspection
+- Client management endpoints (admin only)
+
+**Scopes supported:** `openid`, `profile`, `email`, `read:users`, `write:users`, `admin`
+
+**OAuth Configuration (backend `.env`):**
+```bash
+# OAuth Social Login (as OAuth Consumer)
+OAUTH_ENABLED=true                           # Enable OAuth social login
+OAUTH_AUTO_LINK_BY_EMAIL=true                # Auto-link accounts by email
+OAUTH_STATE_EXPIRE_MINUTES=10                # CSRF state expiration
+
+# Google OAuth
+OAUTH_GOOGLE_CLIENT_ID=your-google-client-id
+OAUTH_GOOGLE_CLIENT_SECRET=your-google-client-secret
+
+# GitHub OAuth
+OAUTH_GITHUB_CLIENT_ID=your-github-client-id
+OAUTH_GITHUB_CLIENT_SECRET=your-github-client-secret
+
+# OAuth Provider Mode (as Authorization Server for MCP)
+OAUTH_PROVIDER_ENABLED=true                  # Enable OAuth provider mode
+OAUTH_ISSUER=https://api.yourdomain.com      # JWT issuer URL (must be HTTPS in production)
+```
+
+### Database Pattern
+- **Async SQLAlchemy 2.0** with PostgreSQL
+- **Connection pooling**: 20 base connections, 50 max overflow
+- **Repository base class**: `repositories/base.py` with common operations
+- **Migrations**: Alembic with helper script `migrate.py`
+  - `python migrate.py auto "message"` - Generate and apply
+  - `python migrate.py list` - View history
+
+### Frontend State Management
+- **Zustand stores**: Lightweight state management
+- **TanStack Query**: API data fetching/caching
+- **Auto-generated client**: From OpenAPI spec via `bun run generate:api`
+- **Dependency Injection**: ALWAYS use `useAuth()` from `AuthContext`, NEVER import `useAuthStore` directly
+
+### Internationalization (i18n)
+- **next-intl v4**: Type-safe internationalization library
+- **Locale routing**: `/en/*`, `/it/*` (English and Italian supported)
+- **Translation files**: `frontend/messages/en.json`, `frontend/messages/it.json`
+- **LocaleSwitcher**: Component for seamless language switching
+- **SEO-friendly**: Locale-aware metadata, sitemaps, and robots.txt
+- **Type safety**: Full TypeScript support for translations
+- **Utilities**: `frontend/src/lib/i18n/` (metadata, routing, utils)
+
+### Organization System
+Three-tier RBAC:
+- **Owner**: Full control (delete org, manage all members)
+- **Admin**: Add/remove members, assign admin role (not owner)
+- **Member**: Read-only organization access
+
+Permission dependencies in `api/dependencies/permissions.py`:
+- `require_organization_owner`
+- `require_organization_admin`
+- `require_organization_member`
+- `can_manage_organization_member`
+
+### Testing Infrastructure
+
+**Backend Unit/Integration (pytest + SQLite):**
+- 96% coverage, 987 tests
+- Security-focused: JWT attacks, session hijacking, privilege escalation
+- Async fixtures in `tests/conftest.py`
+- Run: `IS_TEST=True uv run pytest` or `make test`
+- Coverage: `make test-cov`
+
+**Backend E2E (pytest + Testcontainers + Schemathesis):**
+- Real PostgreSQL via Docker containers
+- OpenAPI contract testing with Schemathesis
+- Install: `make install-e2e`
+- Run: `make test-e2e`
+- Schema tests: `make test-e2e-schema`
+- Docs: `backend/docs/E2E_TESTING.md`
+
+**Frontend Unit Tests (Jest):**
+- 97% coverage
+- Component, hook, and utility testing
+- Run: `bun run test`
+- Coverage: `bun run test:coverage`
+
+**Frontend E2E Tests (Playwright):**
+- 56 passing, 1 skipped (zero flaky tests)
+- Complete user flows (auth, navigation, settings)
+- Run: `bun run test:e2e`
+- UI mode: `bun run test:e2e:ui`
+
+### Development Tooling
+
+**Backend:**
+- **uv**: Modern Python package manager (10-100x faster than pip)
+- **Ruff**: All-in-one linting/formatting (replaces Black, Flake8, isort)
+- **Pyright**: Static type checking (strict mode)
+- **pip-audit**: Dependency vulnerability scanning (OSV database)
+- **detect-secrets**: Hardcoded secrets detection
+- **pip-licenses**: License compliance checking
+- **pre-commit**: Git hook framework (Ruff, detect-secrets, standard checks)
+- **Makefile**: `make help` for all commands
+
+**Frontend:**
+- **Next.js 16**: App Router with React 19
+- **TypeScript**: Full type safety
+- **TailwindCSS + shadcn/ui**: Design system
+- **ESLint + Prettier**: Code quality
+
+### Environment Configuration
+
+**Backend** (`.env`):
+```bash
+POSTGRES_USER=postgres
+POSTGRES_PASSWORD=your_password
+POSTGRES_HOST=db
+POSTGRES_PORT=5432
+POSTGRES_DB=app
+
+SECRET_KEY=your-secret-key-min-32-chars
+ENVIRONMENT=development|production
+CSP_MODE=relaxed|strict|disabled
+
+FIRST_SUPERUSER_EMAIL=admin@example.com
+FIRST_SUPERUSER_PASSWORD=admin123
+
+BACKEND_CORS_ORIGINS=["http://localhost:3000"]
+```
+
+**Frontend** (`.env.local`):
+```bash
+NEXT_PUBLIC_API_URL=http://localhost:8000/api/v1
+```
+
+## Common Development Workflows
+
+### Adding a New API Endpoint
+
+1. **Define schema** in `backend/app/schemas/`
+2. **Create repository** in `backend/app/repositories/`
+3. **Implement route** in `backend/app/api/routes/`
+4. **Register router** in `backend/app/api/main.py`
+5. **Write tests** in `backend/tests/api/`
+6. **Generate frontend client**: `bun run generate:api`
+
+### Database Migrations
+
+```bash
+cd backend
+python migrate.py generate "description"  # Create migration
+python migrate.py apply                   # Apply migrations
+python migrate.py auto "description"      # Generate + apply
+```
+
+### Frontend Component Development
+
+1. **Create component** in `frontend/src/components/`
+2. **Follow design system** (see `frontend/docs/design-system/`)
+3. **Use dependency injection** for auth (`useAuth()` not `useAuthStore`)
+4. **Write tests** in `frontend/tests/` or `__tests__/`
+5. **Run type check**: `bun run type-check`
+
+## Security Features
+
+- **Password hashing**: bcrypt with salt rounds
+- **Rate limiting**: 60 req/min default, 10 req/min on auth endpoints
+- **Security headers**: CSP, X-Frame-Options, HSTS, etc.
+- **CSRF protection**: Built into FastAPI
+- **Session revocation**: Database-backed session tracking
+- **Comprehensive security tests**: JWT algorithm attacks, session hijacking, privilege escalation
+- **Dependency vulnerability scanning**: `make dep-audit` (pip-audit against OSV database)
+- **License compliance**: `make license-check` (blocks GPL-3.0/AGPL)
+- **Secrets detection**: Pre-commit hook blocks hardcoded secrets
+- **Unified security pipeline**: `make audit` (all security checks), `make check` (quality + security + tests)
+
+## Docker Deployment
+
+```bash
+# Development (with hot reload)
+docker-compose -f docker-compose.dev.yml up
+
+# Production
+docker-compose up -d
+
+# Run migrations
+docker-compose exec backend alembic upgrade head
+
+# Create first superuser
+docker-compose exec backend python -c "from app.init_db import init_db; import asyncio; asyncio.run(init_db())"
+```
+
+## Documentation
+
+**For comprehensive documentation, see:**
+- **[README.md](./README.md)** - User-facing project overview
+- **[CLAUDE.md](./CLAUDE.md)** - Claude Code-specific guidance
+- **Backend docs**: `backend/docs/` (Architecture, Coding Standards, Common Pitfalls, Feature Examples)
+- **Frontend docs**: `frontend/docs/` (Design System, Architecture, E2E Testing)
+- **API docs**: http://localhost:8000/docs (Swagger UI when running)
+
+## Current Status (Nov 2025)
+
+### Completed Features ✅
+- Authentication system (JWT with refresh tokens, OAuth/social login)
+- **OAuth Provider Mode (MCP-ready)**: Full OAuth 2.0 Authorization Server
+- Session management (device tracking, revocation)
+- User management (full lifecycle, password change)
+- Organization system (multi-tenant with RBAC)
+- Admin panel (user/org management, bulk operations)
+- **Internationalization (i18n)** with English and Italian
+- Comprehensive test coverage (96% backend, 97% frontend unit, 56 E2E tests)
+- Design system documentation
+- **Marketing landing page** with animations
+- **`/dev` documentation portal** with live examples
+- **Toast notifications**, charts, markdown rendering
+- **SEO optimization** (sitemap, robots.txt, locale metadata)
+- Docker deployment
+
+### In Progress 🚧
+- Frontend admin pages (70% complete)
+- Email integration (templates ready, SMTP pending)
+
+### Planned 🔮
+- GitHub Actions CI/CD
+- Additional languages (Spanish, French, German, etc.)
+- SSO/SAML authentication
+- Real-time notifications (WebSockets)
+- Webhook system
+- Background job processing
+- File upload/storage

CLAUDE.md

@@ -1,10 +1,14 @@
 # CLAUDE.md
 
-This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+Claude Code context for FastAPI + Next.js Full-Stack Template.
 
-## Critical User Preferences
+**See [AGENTS.md](./AGENTS.md) for project context, architecture, and development commands.**
 
-### File Operations - NEVER Use Heredoc/Cat Append
+## Claude Code-Specific Guidance
+
+### Critical User Preferences
+
+#### File Operations - NEVER Use Heredoc/Cat Append
 **ALWAYS use Read/Write/Edit tools instead of `cat >> file << EOF` commands.**
 
 This triggers manual approval dialogs and disrupts workflow.
@@ -18,193 +22,53 @@ EOF
 # CORRECT ✅ - Use Read, then Write tools
 ```
 
-### Work Style
+#### Work Style
 - User prefers autonomous operation without frequent interruptions
 - Ask for batch permissions upfront for long work sessions
 - Work independently, document decisions clearly
+- Only use emojis if the user explicitly requests it
 
-## Project Architecture
+### When Working with This Stack
 
-This is a **FastAPI + Next.js full-stack application** with the following structure:
+**Dependency Management:**
+- Backend uses **uv** (modern Python package manager), not pip
+- Always use `uv run` prefix: `IS_TEST=True uv run pytest`
+- Or use Makefile commands: `make test`, `make install-dev`
+- Add dependencies: `uv add <package>` or `uv add --dev <package>`
 
-### Backend (FastAPI)
-```
-backend/app/
-├── api/            # API routes organized by version
-│   ├── routes/     # Endpoint implementations (auth, users, sessions, admin, organizations)
-│   └── dependencies/ # FastAPI dependencies (auth, permissions)
-├── core/           # Core functionality
-│   ├── config.py   # Settings (Pydantic BaseSettings)
-│   ├── database.py # SQLAlchemy async engine setup
-│   ├── auth.py     # JWT token generation/validation
-│   └── exceptions.py # Custom exception classes and handlers
-├── crud/           # Database CRUD operations (base, user, session, organization)
-├── models/         # SQLAlchemy ORM models
-├── schemas/        # Pydantic request/response schemas
-├── services/       # Business logic layer (auth_service)
-└── utils/          # Utilities (security, device detection, test helpers)
-```
+**Database Migrations:**
+- Use the `migrate.py` helper script, not Alembic directly
+- Generate + apply: `python migrate.py auto "message"`
+- Never commit migrations without testing them first
+- Check current state: `python migrate.py current`
 
-### Frontend (Next.js 15)
-```
-frontend/src/
-├── app/            # Next.js App Router pages
-├── components/     # React components (auth/, ui/)
-├── lib/
-│   ├── api/        # API client (auto-generated from OpenAPI)
-│   ├── stores/     # Zustand state management
-│   └── utils/      # Utility functions
-└── hooks/          # Custom React hooks
-```
+**Frontend API Client Generation:**
+- Run `bun run generate:api` after backend schema changes
+- Client is auto-generated from OpenAPI spec
+- Located in `frontend/src/lib/api/generated/`
+- NEVER manually edit generated files
 
-## Development Commands
+**Testing Commands:**
+- Backend unit/integration: `IS_TEST=True uv run pytest` (always prefix with `IS_TEST=True`)
+- Backend E2E (requires Docker): `make test-e2e`
+- Frontend unit: `bun run test`
+- Frontend E2E: `bun run test:e2e`
+- Use `make test` or `make test-cov` in backend for convenience
 
-### Backend
+**Security & Quality Commands (Backend):**
+- `make validate` — lint + format + type checks
+- `make audit` — dependency vulnerabilities + license compliance
+- `make validate-all` — quality + security checks
+- `make check` — **full pipeline**: quality + security + tests
 
-#### Setup
-```bash
-cd backend
-python -m venv .venv
-source .venv/bin/activate  # or .venv\Scripts\activate on Windows
-pip install -r requirements.txt
-```
-
-#### Database Migrations
-```bash
-# Using the migration helper (preferred)
-python migrate.py generate "migration message"  # Generate migration
-python migrate.py apply                         # Apply migrations
-python migrate.py auto "message"                # Generate and apply in one step
-python migrate.py list                          # List all migrations
-python migrate.py current                       # Show current revision
-python migrate.py check                         # Check DB connection
-
-# Or using Alembic directly
-alembic revision --autogenerate -m "message"
-alembic upgrade head
-```
-
-#### Testing
-
-**Test Coverage: High (comprehensive test suite)**
-- Security-focused testing with JWT algorithm attack prevention (CVE-2015-9235)
-- Session hijacking and privilege escalation tests included
-- Missing lines justified as defensive code, error handlers, and production-only code
-
-```bash
-# Run all tests (uses pytest-xdist for parallel execution)
-IS_TEST=True pytest
-
-# Run with coverage (use -n 0 for accurate coverage)
-IS_TEST=True pytest --cov=app --cov-report=term-missing -n 0
-
-# Run specific test file
-IS_TEST=True pytest tests/api/test_auth.py -v
-
-# Run single test
-IS_TEST=True pytest tests/api/test_auth.py::TestLogin::test_login_success -v
-
-# Run with HTML coverage report
-IS_TEST=True pytest --cov=app --cov-report=html -n 0
-open htmlcov/index.html
-```
-
-#### Running Locally
-```bash
-cd backend
-source .venv/bin/activate
-uvicorn app.main:app --reload --host 0.0.0.0 --port 8000
-```
-
-### Frontend
-
-#### Setup
-```bash
-cd frontend
-npm install
-```
-
-#### Development
-```bash
-npm run dev          # Start dev server on http://localhost:3000
-npm run build        # Production build
-npm run lint         # ESLint
-npm run type-check   # TypeScript checking
-```
-
-#### Testing
-```bash
-# Unit tests (Jest)
-npm test                    # Run all unit tests
-npm run test:watch          # Watch mode
-npm run test:coverage       # With coverage
-
-# E2E tests (Playwright)
-npm run test:e2e            # Run all E2E tests
-npm run test:e2e:ui         # Open Playwright UI
-npm run test:e2e:debug      # Debug mode
-npx playwright test auth-login.spec.ts  # Run specific file
-```
-
-**E2E Test Best Practices:**
-- Use `Promise.all()` pattern for Next.js Link navigation:
-  ```typescript
-  await Promise.all([
-    page.waitForURL('/target', { timeout: 10000 }),
-    link.click()
-  ]);
-  ```
-- Use ID-based selectors for validation errors (e.g., `#email-error`)
-- Error IDs use dashes not underscores (`#new-password-error`)
-- Target `.border-destructive[role="alert"]` to avoid Next.js route announcer conflicts
-- Uses 12 workers in non-CI mode (`workers: 12` in `playwright.config.ts`)
-- URL assertions should use regex to handle query params: `/\/auth\/login/`
-
-### Docker
-
-```bash
-# Development (with hot reload)
-docker-compose -f docker-compose.dev.yml up
-
-# Production
-docker-compose up -d
-
-# Rebuild specific service
-docker-compose build backend
-docker-compose build frontend
-```
-
-## Key Architectural Patterns
-
-### Authentication Flow
-1. **Login**: `POST /api/v1/auth/login` returns access + refresh tokens
-   - Access token: 15 minutes expiry (JWT)
-   - Refresh token: 7 days expiry (JWT with JTI stored in DB)
-   - Session tracking with device info (IP, user agent, device ID)
-
-2. **Token Refresh**: `POST /api/v1/auth/refresh` validates refresh token JTI
-   - Checks session is active in database
-   - Issues new access token (refresh token remains valid)
-   - Updates session `last_used_at`
-
-3. **Authorization**: FastAPI dependencies in `api/dependencies/auth.py`
-   - `get_current_user`: Validates access token, returns User (raises 401 if invalid)
-   - `get_current_active_user`: Requires valid access token + active account
-   - `get_optional_current_user`: Accepts both authenticated and anonymous users (returns User or None)
-   - `get_current_superuser`: Requires superuser flag
-
-### Database Pattern: Async SQLAlchemy
-- **Engine**: Created in `core/database.py` with connection pooling
-- **Sessions**: AsyncSession from `async_sessionmaker`
-- **CRUD**: Base class in `crud/base.py` with common operations
-  - Inherits: `CRUDUser`, `CRUDSession`, `CRUDOrganization`
-  - Pattern: `async def get(db: AsyncSession, id: str) -> Model | None`
-
-### Frontend State Management
-- **Zustand stores**: `lib/stores/` (authStore, etc.)
-- **TanStack Query**: API data fetching/caching
-- **Auto-generated client**: `lib/api/generated/` from OpenAPI spec
-  - Generate with: `npm run generate:api` (runs `scripts/generate-api-client.sh`)
+**Backend E2E Testing (requires Docker):**
+- Install deps: `make install-e2e`
+- Run all E2E tests: `make test-e2e`
+- Run schema tests only: `make test-e2e-schema`
+- Run all tests: `make test-all` (unit + E2E)
+- Uses Testcontainers (real PostgreSQL) + Schemathesis (OpenAPI contract testing)
+- Markers: `@pytest.mark.e2e`, `@pytest.mark.postgres`, `@pytest.mark.schemathesis`
+- See: `backend/docs/E2E_TESTING.md` for complete guide
 
 ### 🔴 CRITICAL: Auth Store Dependency Injection Pattern
 
@@ -230,394 +94,160 @@ const { user, isAuthenticated } = useAuth();
 1. `AuthContext.tsx` - DI boundary, legitimately needs real store
 2. `client.ts` - Non-React context, uses dynamic import + `__TEST_AUTH_STORE__` check
 
-**See**: `frontend/docs/ARCHITECTURE_FIX_REPORT.md` for full details.
+### E2E Test Best Practices
 
-### Session Management Architecture
-**Database-backed session tracking** (not just JWT):
-- Each refresh token has a corresponding `UserSession` record
-- Tracks: device info, IP, location, last used timestamp
-- Supports session revocation (logout from specific devices)
-- Cleanup job removes expired sessions
+When writing or fixing Playwright tests:
 
-### Permission System
-Three-tier organization roles:
-- **Owner**: Full control (delete org, manage all members)
-- **Admin**: Can add/remove members, assign admin role (not owner)
-- **Member**: Read-only organization access
+**Navigation Pattern:**
+```typescript
+// ✅ CORRECT - Use Promise.all for Next.js Link clicks
+await Promise.all([
+  page.waitForURL('/target', { timeout: 10000 }),
+  link.click()
+]);
+```
 
-Dependencies in `api/dependencies/permissions.py`:
-- `require_organization_owner`
-- `require_organization_admin`
-- `require_organization_member`
-- `can_manage_organization_member` (owner or admin, but not self-demotion)
+**Selectors:**
+- Use ID-based selectors for validation errors: `#email-error`
+- Error IDs use dashes not underscores: `#new-password-error`
+- Target `.border-destructive[role="alert"]` to avoid Next.js route announcer conflicts
+- Avoid generic `[role="alert"]` which matches multiple elements
 
-## Testing Infrastructure
+**URL Assertions:**
+```typescript
+// ✅ Use regex to handle query params
+await expect(page).toHaveURL(/\/auth\/login/);
 
-### Backend Test Patterns
+// ❌ Don't use exact strings (fails with query params)
+await expect(page).toHaveURL('/auth/login');
+```
 
-**Fixtures** (in `tests/conftest.py`):
-- `async_test_db`: Fresh SQLite in-memory database per test
-- `client`: AsyncClient with test database override
-- `async_test_user`: Pre-created regular user
-- `async_test_superuser`: Pre-created superuser
-- `user_token` / `superuser_token`: Access tokens for API calls
+**Configuration:**
+- Uses 12 workers in non-CI mode (`playwright.config.ts`)
+- Reduces to 2 workers in CI for stability
+- Tests are designed to be non-flaky with proper waits
 
-**Database Mocking for Exception Testing**:
+### Important Implementation Details
+
+**Authentication Testing:**
+- Backend fixtures in `tests/conftest.py`:
+  - `async_test_db`: Fresh SQLite per test
+  - `async_test_user` / `async_test_superuser`: Pre-created users
+  - `user_token` / `superuser_token`: Access tokens for API calls
+- Always use `@pytest.mark.asyncio` for async tests
+- Use `@pytest_asyncio.fixture` for async fixtures
+
+**Database Testing:**
 ```python
+# Mock database exceptions correctly
 from unittest.mock import patch, AsyncMock
 
-# Mock database commit to raise exception
 async def mock_commit():
     raise OperationalError("Connection lost", {}, Exception())
 
 with patch.object(session, 'commit', side_effect=mock_commit):
     with patch.object(session, 'rollback', new_callable=AsyncMock) as mock_rollback:
         with pytest.raises(OperationalError):
-            await crud_method(session, obj_in=data)
+            await repo_method(session, obj_in=data)
         mock_rollback.assert_called_once()
 ```
 
-**Testing Routes**:
-```python
-@pytest.mark.asyncio
-async def test_endpoint(client, user_token):
-    response = await client.get(
-        "/api/v1/endpoint",
-        headers={"Authorization": f"Bearer {user_token}"}
-    )
-    assert response.status_code == 200
-```
-
-**IMPORTANT**: Use `@pytest_asyncio.fixture` for async fixtures, not `@pytest.fixture`
-
-### Frontend Test Patterns
-
-**Unit Tests (Jest)**:
-```typescript
-// SSR-safe mocking
-jest.mock('@/lib/stores/authStore', () => ({
-  useAuthStore: jest.fn()
-}));
-
-beforeEach(() => {
-  (useAuthStore as jest.Mock).mockReturnValue({
-    user: mockUser,
-    login: mockLogin
-  });
-});
-```
-
-**E2E Tests (Playwright)**:
-```typescript
-test('navigation', async ({ page }) => {
-  await page.goto('/');
-
-  const link = page.getByRole('link', { name: 'Login' });
-  await Promise.all([
-    page.waitForURL(/\/auth\/login/, { timeout: 10000 }),
-    link.click()
-  ]);
-
-  await expect(page).toHaveURL(/\/auth\/login/);
-});
-```
-
-## Configuration
-
-### Environment Variables
-
-**Backend** (`.env`):
-```bash
-# Database
-POSTGRES_USER=postgres
-POSTGRES_PASSWORD=your_password
-POSTGRES_HOST=db
-POSTGRES_PORT=5432
-POSTGRES_DB=app
-
-# Security
-SECRET_KEY=your-secret-key-min-32-chars
-ENVIRONMENT=development|production
-CSP_MODE=relaxed|strict|disabled
-
-# First Superuser (auto-created on init)
-FIRST_SUPERUSER_EMAIL=admin@example.com
-FIRST_SUPERUSER_PASSWORD=admin123
-
-# CORS
-BACKEND_CORS_ORIGINS=["http://localhost:3000"]
-```
-
-**Frontend** (`.env.local`):
-```bash
-NEXT_PUBLIC_API_URL=http://localhost:8000/api/v1
-```
-
-### Database Connection Pooling
-Configured in `core/config.py`:
-- `db_pool_size`: 20 (default connections)
-- `db_max_overflow`: 50 (max overflow)
-- `db_pool_timeout`: 30 seconds
-- `db_pool_recycle`: 3600 seconds (recycle after 1 hour)
-
-### Security Headers
-Automatically applied via middleware in `main.py`:
-- `X-Frame-Options: DENY`
-- `X-Content-Type-Options: nosniff`
-- `X-XSS-Protection: 1; mode=block`
-- `Strict-Transport-Security` (production only)
-- Content-Security-Policy (configurable via `CSP_MODE`)
-
-### Rate Limiting
-- Implemented with `slowapi`
-- Default: 60 requests/minute per IP
-- Applied to auth endpoints (login, register, password reset)
-- Override in route decorators: `@limiter.limit("10/minute")`
-
-## Common Workflows
-
-### Adding a New API Endpoint
-
-1. **Create schema** (`backend/app/schemas/`):
-   ```python
-   class ItemCreate(BaseModel):
-       name: str
-       description: Optional[str] = None
-
-   class ItemResponse(BaseModel):
-       id: UUID
-       name: str
-       created_at: datetime
-   ```
-
-2. **Create CRUD operations** (`backend/app/crud/`):
-   ```python
-   class CRUDItem(CRUDBase[Item, ItemCreate, ItemUpdate]):
-       async def get_by_name(self, db: AsyncSession, name: str) -> Item | None:
-           result = await db.execute(select(Item).where(Item.name == name))
-           return result.scalar_one_or_none()
-
-   item = CRUDItem(Item)
-   ```
-
-3. **Create route** (`backend/app/api/routes/items.py`):
-   ```python
-   from app.api.dependencies.auth import get_current_user
-
-   @router.post("/", response_model=ItemResponse)
-   async def create_item(
-       item_in: ItemCreate,
-       current_user: User = Depends(get_current_user),
-       db: AsyncSession = Depends(get_db)
-   ):
-       item = await item_crud.create(db, obj_in=item_in)
-       return item
-   ```
-
-4. **Register router** (`backend/app/api/main.py`):
-   ```python
-   from app.api.routes import items
-   api_router.include_router(items.router, prefix="/items", tags=["Items"])
-   ```
-
-5. **Write tests** (`backend/tests/api/test_items.py`):
-   ```python
-   @pytest.mark.asyncio
-   async def test_create_item(client, user_token):
-       response = await client.post(
-           "/api/v1/items",
-           headers={"Authorization": f"Bearer {user_token}"},
-           json={"name": "Test Item"}
-       )
-       assert response.status_code == 201
-   ```
-
-6. **Generate frontend client**:
-   ```bash
-   cd frontend
-   npm run generate:api
-   ```
-
-### Adding a New React Component
-
-1. **Create component** (`frontend/src/components/`):
-   ```typescript
-   export function MyComponent() {
-     const { user } = useAuthStore();
-     return <div>Hello {user?.firstName}</div>;
-   }
-   ```
-
-2. **Add tests** (`frontend/src/components/__tests__/`):
-   ```typescript
-   import { render, screen } from '@testing-library/react';
-
-   test('renders component', () => {
-     render(<MyComponent />);
-     expect(screen.getByText(/Hello/)).toBeInTheDocument();
-   });
-   ```
-
-3. **Add to page** (`frontend/src/app/page.tsx`):
-   ```typescript
-   import { MyComponent } from '@/components/MyComponent';
-
-   export default function Page() {
-     return <MyComponent />;
-   }
-   ```
-
-## Current Project Status (Nov 2025)
-
-### Completed Features
-- ✅ Authentication system (JWT with refresh tokens)
-- ✅ Session management (device tracking, revocation)
-- ✅ User management (CRUD, password change)
-- ✅ Organization system (multi-tenant with roles)
-- ✅ Admin panel (user/org management, bulk operations)
-- ✅ E2E test suite (56 passing, 1 skipped, zero flaky tests)
-
-### Test Coverage
-- **Backend**: 97% overall (743 tests, all passing) ✅
-  - Comprehensive security testing (JWT attacks, session hijacking, privilege escalation)
-  - User CRUD: 100% ✅
-  - Session CRUD: 100% ✅
-  - Auth routes: 99% ✅
-  - Organization routes: 100% ✅
-  - Permissions: 100% ✅
-  - 84 missing lines justified (defensive code, error handlers, production-only code)
-
-- **Frontend E2E**: 56 passing, 1 skipped across 7 files ✅
-  - auth-login.spec.ts (19 tests)
-  - auth-register.spec.ts (14 tests)
-  - auth-password-reset.spec.ts (10 tests)
-  - navigation.spec.ts (10 tests)
-  - settings-password.spec.ts (3 tests)
-  - settings-profile.spec.ts (2 tests)
-  - settings-navigation.spec.ts (5 tests)
-  - settings-sessions.spec.ts (1 skipped - route not yet implemented)
-
-## Email Service Integration
-
-The project includes a **placeholder email service** (`backend/app/services/email_service.py`) designed for easy integration with production email providers.
-
-### Current Implementation
-
-**Console Backend (Default)**:
-- Logs email content to console/logs instead of sending
-- Safe for development and testing
-- No external dependencies required
-
-### Production Integration
-
-To enable email functionality, implement one of these approaches:
-
-**Option 1: SMTP Integration** (Recommended for most use cases)
-```python
-# In app/services/email_service.py, complete the SMTPEmailBackend implementation
-from aiosmtplib import SMTP
-from email.mime.text import MIMEText
-from email.mime.multipart import MIMEMultipart
-
-# Add environment variables to .env:
-# SMTP_HOST=smtp.gmail.com
-# SMTP_PORT=587
-# SMTP_USERNAME=your-email@gmail.com
-# SMTP_PASSWORD=your-app-password
-```
-
-**Option 2: Third-Party Service** (SendGrid, AWS SES, Mailgun, etc.)
-```python
-# Create a new backend class, e.g., SendGridEmailBackend
-class SendGridEmailBackend(EmailBackend):
-    def __init__(self, api_key: str):
-        self.api_key = api_key
-        self.client = sendgrid.SendGridAPIClient(api_key)
-
-    async def send_email(self, to, subject, html_content, text_content=None):
-        # Implement SendGrid sending logic
-        pass
-
-# Update global instance in email_service.py:
-# email_service = EmailService(SendGridEmailBackend(settings.SENDGRID_API_KEY))
-```
-
-**Option 3: External Microservice**
-- Use a dedicated email microservice via HTTP API
-- Implement `HTTPEmailBackend` that makes async HTTP requests
-
-### Email Templates Included
-
-The service includes pre-built templates for:
-- **Password Reset**: `send_password_reset_email()` - 1 hour expiry
-- **Email Verification**: `send_email_verification()` - 24 hour expiry
-
-Both include responsive HTML and plain text versions.
-
-### Integration Points
-
-Email sending is called from:
-- `app/api/routes/auth.py` - Password reset flow (placeholder comments)
-- Registration flow - Ready for email verification integration
-
-**Note**: Current auth routes have placeholder comments where email functionality should be integrated. Search for "TODO: Send email" in the codebase.
-
-## API Documentation
-
-Once backend is running:
-- **Swagger UI**: http://localhost:8000/docs
-- **ReDoc**: http://localhost:8000/redoc
-- **OpenAPI JSON**: http://localhost:8000/api/v1/openapi.json
-
-## Troubleshooting
-
-### Tests failing with "Module was never imported"
-Run with single process: `pytest -n 0`
-
-### Coverage not improving despite new tests
-- Verify tests actually execute endpoints (check response.status_code)
-- Generate HTML coverage: `pytest --cov=app --cov-report=html -n 0`
-- Check for dependency override issues in test fixtures
-
-### Frontend type errors
-```bash
-npm run type-check          # Check all types
-npx tsc --noEmit           # Same but shorter
-```
-
-### E2E tests flaking
-- Check worker count (should be 4, not 16+)
-- Use `Promise.all()` for navigation
-- Use regex for URL assertions
-- Target specific selectors (avoid generic `[role="alert"]`)
-
-### Database migration conflicts
-```bash
-python migrate.py list      # Check migration history
-alembic downgrade -1        # Downgrade one revision
-alembic upgrade head        # Re-apply
-```
-
-## Additional Documentation
-
-### Backend Documentation
-- `backend/docs/ARCHITECTURE.md`: System architecture and design patterns
-- `backend/docs/CODING_STANDARDS.md`: Code quality standards and best practices
-- `backend/docs/COMMON_PITFALLS.md`: Common mistakes and how to avoid them
-- `backend/docs/FEATURE_EXAMPLE.md`: Step-by-step feature implementation guide
-
-### Frontend Documentation
-- **`frontend/docs/ARCHITECTURE_FIX_REPORT.md`**: ⭐ Critical DI pattern fixes (READ THIS!)
-- `frontend/e2e/README.md`: E2E testing setup and guidelines
-- **`frontend/docs/design-system/`**: Comprehensive design system documentation
-  - `README.md`: Hub with learning paths (start here)
-  - `00-quick-start.md`: 5-minute crash course
-  - `01-foundations.md`: Colors (OKLCH), typography, spacing, shadows
-  - `02-components.md`: shadcn/ui component library guide
-  - `03-layouts.md`: Layout patterns (Grid vs Flex decision trees)
-  - `04-spacing-philosophy.md`: Parent-controlled spacing strategy
-  - `05-component-creation.md`: When to create vs compose components
-  - `06-forms.md`: Form patterns with react-hook-form + Zod
-  - `07-accessibility.md`: WCAG AA compliance, keyboard navigation, screen readers
-  - `08-ai-guidelines.md`: **AI code generation rules (read this!)**
-  - `99-reference.md`: Quick reference cheat sheet (bookmark this)
+**Frontend Component Development:**
+- Follow design system docs in `frontend/docs/design-system/`
+- Read `08-ai-guidelines.md` for AI code generation rules
+- Use parent-controlled spacing (see `04-spacing-philosophy.md`)
+- WCAG AA compliance required (see `07-accessibility.md`)
+
+**Security Considerations:**
+- Backend has comprehensive security tests (JWT attacks, session hijacking)
+- Never skip security headers in production
+- Rate limiting is configured in route decorators: `@limiter.limit("10/minute")`
+- Session revocation is database-backed, not just JWT expiry
+- Run `make audit` to check for dependency vulnerabilities and license compliance
+- Run `make check` for the full pipeline: quality + security + tests
+- Pre-commit hooks enforce Ruff lint/format and detect-secrets on every commit
+- Setup hooks: `cd backend && uv run pre-commit install`
+
+### Common Workflows Guidance
+
+**When Adding a New Feature:**
+1. Start with backend schema and repository
+2. Implement API route with proper authorization
+3. Write backend tests (aim for >90% coverage)
+4. Generate frontend API client: `bun run generate:api`
+5. Implement frontend components
+6. Write frontend unit tests
+7. Add E2E tests for critical flows
+8. Update relevant documentation
+
+**When Fixing Tests:**
+- Backend: Check test database isolation and async fixture usage
+- Frontend unit: Verify mocking of `useAuth()` not `useAuthStore`
+- E2E: Use `Promise.all()` pattern and regex URL assertions
+
+**When Debugging:**
+- Backend: Check `IS_TEST=True` environment variable is set
+- Frontend: Run `bun run type-check` first
+- E2E: Use `bun run test:e2e:debug` for step-by-step debugging
+- Check logs: Backend has detailed error logging
+
+**Demo Mode (Frontend-Only Showcase):**
+- Enable: `echo "NEXT_PUBLIC_DEMO_MODE=true" > frontend/.env.local`
+- Uses MSW (Mock Service Worker) to intercept API calls in browser
+- Zero backend required - perfect for Vercel deployments
+- **Fully Automated**: MSW handlers auto-generated from OpenAPI spec
+  - Run `bun run generate:api` → updates both API client AND MSW handlers
+  - No manual synchronization needed!
+- Demo credentials (any password ≥8 chars works):
+  - User: `demo@example.com` / `DemoPass123`
+  - Admin: `admin@example.com` / `AdminPass123`
+- **Safe**: MSW never runs during tests (Jest or Playwright)
+- **Coverage**: Mock files excluded from linting and coverage
+- **Documentation**: `frontend/docs/DEMO_MODE.md` for complete guide
+
+### Tool Usage Preferences
+
+**Prefer specialized tools over bash:**
+- Use Read/Write/Edit tools for file operations
+- Never use `cat`, `echo >`, or heredoc for file manipulation
+- Use Task tool with `subagent_type=Explore` for codebase exploration
+- Use Grep tool for code search, not bash `grep`
+
+**When to use parallel tool calls:**
+- Independent git commands: `git status`, `git diff`, `git log`
+- Reading multiple unrelated files
+- Running multiple test suites simultaneously
+- Independent validation steps
+
+## Custom Skills
+
+No Claude Code Skills installed yet. To create one, invoke the built-in "skill-creator" skill.
+
+**Potential skill ideas for this project:**
+- API endpoint generator workflow (schema → repository → route → tests → frontend client)
+- Component generator with design system compliance
+- Database migration troubleshooting helper
+- Test coverage analyzer and improvement suggester
+- E2E test generator for new features
+
+## Additional Resources
+
+**Comprehensive Documentation:**
+- [AGENTS.md](./AGENTS.md) - Framework-agnostic AI assistant context
+- [README.md](./README.md) - User-facing project overview
+- `backend/docs/` - Backend architecture, coding standards, common pitfalls
+- `frontend/docs/design-system/` - Complete design system guide
+
+**API Documentation (when running):**
+- Swagger UI: http://localhost:8000/docs
+- ReDoc: http://localhost:8000/redoc
+- OpenAPI JSON: http://localhost:8000/api/v1/openapi.json
+
+**Testing Documentation:**
+- Backend tests: `backend/tests/` (97% coverage)
+- Frontend E2E: `frontend/e2e/README.md`
+- Design system: `frontend/docs/design-system/08-ai-guidelines.md`
+
+---
+
+**For project architecture, development commands, and general context, see [AGENTS.md](./AGENTS.md).**

CONTRIBUTING.md

@@ -90,22 +90,27 @@ Ready to write some code? Awesome!
 ```bash
 cd backend
 
-# Setup virtual environment
-python -m venv .venv
-source .venv/bin/activate
+# Install dependencies (uv manages virtual environment automatically)
+make install-dev
 
-# Install dependencies
-pip install -r requirements.txt
+# Setup pre-commit hooks
+uv run pre-commit install
 
 # Setup environment
 cp .env.example .env
 # Edit .env with your settings
 
 # Run migrations
-alembic upgrade head
+python migrate.py apply
+
+# Run quality + security checks
+make validate-all
 
 # Run tests
-IS_TEST=True pytest
+make test
+
+# Run full pipeline (quality + security + tests)
+make check
 
 # Start dev server
 uvicorn app.main:app --reload
@@ -117,20 +122,20 @@ uvicorn app.main:app --reload
 cd frontend
 
 # Install dependencies
-npm install
+bun install
 
 # Setup environment
 cp .env.local.example .env.local
 
 # Generate API client
-npm run generate:api
+bun run generate:api
 
 # Run tests
-npm test
-npm run test:e2e:ui
+bun run test
+bun run test:e2e:ui
 
 # Start dev server
-npm run dev
+bun run dev
 ```
 
 ---
@@ -199,7 +204,7 @@ export function UserProfile({ userId }: UserProfileProps) {
 
 ### Key Patterns
 
-- **Backend**: Use CRUD pattern, keep routes thin, business logic in services
+- **Backend**: Use repository pattern, keep routes thin, business logic in services
 - **Frontend**: Use React Query for server state, Zustand for client state
 - **Both**: Handle errors gracefully, log appropriately, write tests
 
@@ -320,7 +325,7 @@ Fixed stuff
 ### Before Submitting
 
 - [ ] Code follows project style guidelines
-- [ ] All tests pass locally
+- [ ] `make check` passes (quality + security + tests) in backend
 - [ ] New tests added for new features
 - [ ] Documentation updated if needed
 - [ ] No merge conflicts with `main`

Makefile

@@ -1,31 +1,124 @@
-.PHONY: dev prod down clean clean-slate
+.PHONY: help dev dev-full prod down logs logs-dev clean clean-slate drop-db reset-db push-images deploy scan-images
 
 VERSION ?= latest
-REGISTRY := gitea.pragmazest.com/cardosofelipe/app
+REGISTRY ?= ghcr.io/cardosofelipe/pragma-stack
 
+# Default target
+help:
+	@echo "FastAPI + Next.js Full-Stack Template"
+	@echo ""
+	@echo "Development:"
+	@echo "  make dev           - Start backend + db (frontend runs separately)"
+	@echo "  make dev-full      - Start all services including frontend"
+	@echo "  make down          - Stop all services"
+	@echo "  make logs-dev      - Follow dev container logs"
+	@echo ""
+	@echo "Database:"
+	@echo "  make drop-db       - Drop and recreate empty database"
+	@echo "  make reset-db      - Drop database and apply all migrations"
+	@echo ""
+	@echo "Production:"
+	@echo "  make prod          - Start production stack"
+	@echo "  make deploy        - Pull and deploy latest images"
+	@echo "  make push-images   - Build and push images to registry"
+	@echo "  make scan-images   - Scan production images for CVEs (requires trivy)"
+	@echo "  make logs          - Follow production container logs"
+	@echo ""
+	@echo "Cleanup:"
+	@echo "  make clean         - Stop containers"
+	@echo "  make clean-slate   - Stop containers AND delete volumes (DATA LOSS!)"
+	@echo ""
+	@echo "Subdirectory commands:"
+	@echo "  cd backend && make help   - Backend-specific commands"
+	@echo "  cd frontend && npm run    - Frontend-specific commands"
+
+# ============================================================================
+# Development
+# ============================================================================
 
 dev:
-	docker compose -f docker-compose.dev.yml up --build -d
+	# Bring up all dev services except the frontend
+	docker compose -f docker-compose.dev.yml up --build -d --scale frontend=0
+	@echo ""
+	@echo "Frontend is not started by 'make dev'."
+	@echo "To run the frontend locally, open a new terminal and run:"
+	@echo "    cd frontend && npm run dev"
 
-prod:
-	docker compose up --build -d
+dev-full:
+	# Bring up all dev services including the frontend (full stack)
+	docker compose -f docker-compose.dev.yml up --build -d
 
 down:
 	docker compose down
 
+logs:
+	docker compose logs -f
+
+logs-dev:
+	docker compose -f docker-compose.dev.yml logs -f
+
+# ============================================================================
+# Database Management
+# ============================================================================
+
+drop-db:
+	@echo "Dropping local database..."
+	@docker compose -f docker-compose.dev.yml exec -T db psql -U postgres -c "DROP DATABASE IF EXISTS app WITH (FORCE);" 2>/dev/null || \
+		docker compose -f docker-compose.dev.yml exec -T db psql -U postgres -c "DROP DATABASE IF EXISTS app;"
+	@docker compose -f docker-compose.dev.yml exec -T db psql -U postgres -c "CREATE DATABASE app;"
+	@echo "Database dropped and recreated (empty)"
+
+reset-db: drop-db
+	@echo "Applying migrations..."
+	@cd backend && uv run python migrate.py --local apply
+	@echo "Database reset complete!"
+
+# ============================================================================
+# Production / Deployment
+# ============================================================================
+
+prod:
+	docker compose up --build -d
+
 deploy:
 	docker compose -f docker-compose.deploy.yml pull
 	docker compose -f docker-compose.deploy.yml up -d
 
-clean:
-	docker compose down -
-
-# WARNING! THIS REMOVES CONTAINERS AND VOLUMES AS WELL - DO NOT USE THIS UNLESS YOU WANT TO START OVER WITH DATA AND ALL
-clean-slate:
-	docker compose down -v
-
 push-images:
 	docker build -t $(REGISTRY)/backend:$(VERSION) ./backend
 	docker build -t $(REGISTRY)/frontend:$(VERSION) ./frontend
 	docker push $(REGISTRY)/backend:$(VERSION)
-	docker push $(REGISTRY)/frontend:$(VERSION)
+	docker push $(REGISTRY)/frontend:$(VERSION)
+
+scan-images:
+	@docker info > /dev/null 2>&1 || (echo "❌ Docker is not running!"; exit 1)
+	@echo "🐳 Building and scanning production images for CVEs..."
+	docker build -t $(REGISTRY)/backend:scan --target production ./backend
+	docker build -t $(REGISTRY)/frontend:scan --target runner ./frontend
+	@echo ""
+	@echo "=== Backend Image Scan ==="
+	@if command -v trivy > /dev/null 2>&1; then \
+		trivy image --severity HIGH,CRITICAL --exit-code 1 $(REGISTRY)/backend:scan; \
+	else \
+		echo "ℹ️  Trivy not found locally, using Docker to run Trivy..."; \
+		docker run --rm -v /var/run/docker.sock:/var/run/docker.sock aquasec/trivy image --severity HIGH,CRITICAL --exit-code 1 $(REGISTRY)/backend:scan; \
+	fi
+	@echo ""
+	@echo "=== Frontend Image Scan ==="
+	@if command -v trivy > /dev/null 2>&1; then \
+		trivy image --severity HIGH,CRITICAL --exit-code 1 $(REGISTRY)/frontend:scan; \
+	else \
+		docker run --rm -v /var/run/docker.sock:/var/run/docker.sock aquasec/trivy image --severity HIGH,CRITICAL --exit-code 1 $(REGISTRY)/frontend:scan; \
+	fi
+	@echo "✅ No HIGH/CRITICAL CVEs found in production images!"
+
+# ============================================================================
+# Cleanup
+# ============================================================================
+
+clean:
+	docker compose down
+
+# WARNING! THIS REMOVES CONTAINERS AND VOLUMES AS WELL - DO NOT USE THIS UNLESS YOU WANT TO START OVER WITH DATA AND ALL
+clean-slate:
+	docker compose -f docker-compose.dev.yml down -v --remove-orphans

README.md

@@ -1,29 +1,29 @@
-# FastAPI + Next.js Full-Stack Template
+# <img src="frontend/public/logo.svg" alt="PragmaStack" width="32" height="32" style="vertical-align: middle" /> PragmaStack
 
-> **Production-ready, security-first, full-stack TypeScript/Python template with authentication, multi-tenancy, and a comprehensive admin panel.**
+> **The Pragmatic Full-Stack Template. Production-ready, security-first, and opinionated.**
 
-<!--
-  TODO: Replace these static badges with dynamic CI/CD badges when GitHub Actions is set up
-  Example: https://github.com/YOUR_ORG/YOUR_REPO/actions/workflows/backend-tests.yml/badge.svg
--->
-
-[![Backend Unit Tests](https://img.shields.io/badge/backend_unit_tests-passing-success)](./backend/tests)
 [![Backend Coverage](https://img.shields.io/badge/backend_coverage-97%25-brightgreen)](./backend/tests)
-[![Frontend Unit Tests](https://img.shields.io/badge/frontend_unit_tests-passing-success)](./frontend/tests)
 [![Frontend Coverage](https://img.shields.io/badge/frontend_coverage-97%25-brightgreen)](./frontend/tests)
 [![E2E Tests](https://img.shields.io/badge/e2e_tests-passing-success)](./frontend/e2e)
 [![License: MIT](https://img.shields.io/badge/License-MIT-blue.svg)](./LICENSE)
 [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-brightgreen.svg)](./CONTRIBUTING.md)
 
+![Landing Page](docs/images/landing.png)
+
 ---
 
-## Why This Template?
+## Why PragmaStack?
 
-Building a modern full-stack application from scratch means solving the same problems over and over: authentication, authorization, multi-tenancy, admin panels, session management, database migrations, API documentation, testing infrastructure...
+Building a modern full-stack application often leads to "analysis paralysis" or "boilerplate fatigue". You spend weeks setting up authentication, testing, and linting before writing a single line of business logic.
 
-**This template gives you all of that, battle-tested and ready to go.**
+**PragmaStack cuts through the noise.**
 
-Instead of spending weeks on boilerplate, you can focus on building your unique features. Whether you're building a SaaS product, an internal tool, or a side project, this template provides a rock-solid foundation with modern best practices baked in.
+We provide a **pragmatic**, opinionated foundation that prioritizes:
+- **Speed**: Ship features, not config files.
+- **Robustness**: Security and testing are not optional.
+- **Clarity**: Code that is easy to read and maintain.
+
+Whether you're building a SaaS, an internal tool, or a side project, PragmaStack gives you a solid starting point without the bloat.
 
 ---
 
@@ -31,12 +31,26 @@ Instead of spending weeks on boilerplate, you can focus on building your unique
 
 ### 🔐 **Authentication & Security**
 - JWT-based authentication with access + refresh tokens
+- **OAuth/Social Login** (Google, GitHub) with PKCE support
+- **OAuth 2.0 Authorization Server** (MCP-ready) for third-party integrations
 - Session management with device tracking and revocation
 - Password reset flow (email integration ready)
 - Secure password hashing (bcrypt)
 - CSRF protection, rate limiting, and security headers
 - Comprehensive security tests (JWT algorithm attacks, session hijacking, privilege escalation)
 
+### 🔌 **OAuth Provider Mode (MCP Integration)**
+Full OAuth 2.0 Authorization Server for Model Context Protocol (MCP) and third-party clients:
+- **RFC 7636**: Authorization Code Flow with PKCE (S256 only)
+- **RFC 8414**: Server metadata discovery at `/.well-known/oauth-authorization-server`
+- **RFC 7662**: Token introspection endpoint
+- **RFC 7009**: Token revocation endpoint
+- **JWT access tokens**: Self-contained, configurable lifetime
+- **Opaque refresh tokens**: Secure rotation, database-backed revocation
+- **Consent management**: Users can review and revoke app permissions
+- **Client management**: Admin endpoints for registering OAuth clients
+- **Scopes**: `openid`, `profile`, `email`, `read:users`, `write:users`, `admin`
+
 ### 👥 **Multi-Tenancy & Organizations**
 - Full organization system with role-based access control (Owner, Admin, Member)
 - Invite/remove members, manage permissions
@@ -44,18 +58,35 @@ Instead of spending weeks on boilerplate, you can focus on building your unique
 - User can belong to multiple organizations
 
 ### 🛠️ **Admin Panel**
-- Complete user management (CRUD, activate/deactivate, bulk operations)
+- Complete user management (full lifecycle, activate/deactivate, bulk operations)
 - Organization management (create, edit, delete, member management)
 - Session monitoring across all users
 - Real-time statistics dashboard
 - Admin-only routes with proper authorization
 
 ### 🎨 **Modern Frontend**
-- Next.js 15 with App Router and React 19
-- Comprehensive design system built on shadcn/ui + TailwindCSS
+- Next.js 16 with App Router and React 19
+- **PragmaStack Design System** built on shadcn/ui + TailwindCSS
 - Pre-configured theme with dark mode support (coming soon)
 - Responsive, accessible components (WCAG AA compliant)
-- Developer documentation at `/dev` (in progress)
+- Rich marketing landing page with animated components
+- Live component showcase and documentation at `/dev`
+
+### 🌍 **Internationalization (i18n)**
+- Built-in multi-language support with next-intl v4
+- Locale-based routing (`/en/*`, `/it/*`)
+- Seamless language switching with LocaleSwitcher component
+- SEO-friendly URLs and metadata per locale
+- Translation files for English and Italian (easily extensible)
+- Type-safe translations throughout the app
+
+### 🎯 **Content & UX Features**
+- **Toast notifications** with Sonner for elegant user feedback
+- **Smooth animations** powered by Framer Motion
+- **Markdown rendering** with syntax highlighting (GitHub Flavored Markdown)
+- **Charts and visualizations** ready with Recharts
+- **SEO optimization** with dynamic sitemap and robots.txt generation
+- **Session tracking UI** with device information and revocation controls
 
 ### 🧪 **Comprehensive Testing**
 - **Backend Testing**: ~97% unit test coverage
@@ -75,9 +106,10 @@ Instead of spending weeks on boilerplate, you can focus on building your unique
 ### 📚 **Developer Experience**
 - Auto-generated TypeScript API client from OpenAPI spec
 - Interactive API documentation (Swagger + ReDoc)
-- Database migrations with Alembic
-- Hot reload in development
-- Comprehensive code documentation
+- Database migrations with Alembic helper script
+- Hot reload in development for both frontend and backend
+- Comprehensive code documentation and design system docs
+- Live component playground at `/dev` with code examples
 - Docker support for easy deployment
 - VSCode workspace settings included
 
@@ -89,6 +121,68 @@ Instead of spending weeks on boilerplate, you can focus on building your unique
 - Health check endpoints
 - Production security headers
 - Rate limiting on sensitive endpoints
+- SEO optimization with dynamic sitemaps and robots.txt
+- Multi-language SEO with locale-specific metadata
+- Performance monitoring and bundle analysis
+
+---
+
+## 📸 Screenshots
+
+<details>
+<summary>Click to view screenshots</summary>
+
+### Landing Page
+![Landing Page](docs/images/landing.png)
+
+
+
+### Authentication
+![Login Page](docs/images/login.png)
+
+
+
+### Admin Dashboard
+![Admin Dashboard](docs/images/admin-dashboard.png)
+
+
+
+### Design System
+![Components](docs/images/design-system.png)
+
+</details>
+
+---
+
+## 🎭 Demo Mode
+
+**Try the frontend without a backend!** Perfect for:
+- **Free deployment** on Vercel (no backend costs)
+- **Portfolio showcasing** with live demos
+- **Client presentations** without infrastructure setup
+
+### Quick Start
+
+```bash
+cd frontend
+echo "NEXT_PUBLIC_DEMO_MODE=true" > .env.local
+bun run dev
+```
+
+**Demo Credentials:**
+- Regular user: `demo@example.com` / `DemoPass123`
+- Admin user: `admin@example.com` / `AdminPass123`
+
+Demo mode uses [Mock Service Worker (MSW)](https://mswjs.io/) to intercept API calls in the browser. Your code remains unchanged - the same components work with both real and mocked backends.
+
+**Key Features:**
+- ✅ Zero backend required
+- ✅ All features functional (auth, admin, stats)
+- ✅ Realistic network delays and errors
+- ✅ Does NOT interfere with tests (97%+ coverage maintained)
+- ✅ One-line toggle: `NEXT_PUBLIC_DEMO_MODE=true`
+
+📖 **[Complete Demo Mode Documentation](./frontend/docs/DEMO_MODE.md)**
 
 ---
 
@@ -103,13 +197,18 @@ Instead of spending weeks on boilerplate, you can focus on building your unique
 - **[pytest](https://pytest.org/)** - Testing framework with async support
 
 ### Frontend
-- **[Next.js 15](https://nextjs.org/)** - React framework with App Router
+- **[Next.js 16](https://nextjs.org/)** - React framework with App Router
 - **[React 19](https://react.dev/)** - UI library
 - **[TypeScript](https://www.typescriptlang.org/)** - Type-safe JavaScript
 - **[TailwindCSS](https://tailwindcss.com/)** - Utility-first CSS framework
 - **[shadcn/ui](https://ui.shadcn.com/)** - Beautiful, accessible component library
+- **[next-intl](https://next-intl.dev/)** - Internationalization (i18n) with type safety
 - **[TanStack Query](https://tanstack.com/query)** - Powerful data fetching/caching
 - **[Zustand](https://zustand-demo.pmnd.rs/)** - Lightweight state management
+- **[Framer Motion](https://www.framer.com/motion/)** - Production-ready animation library
+- **[Sonner](https://sonner.emilkowal.ski/)** - Beautiful toast notifications
+- **[Recharts](https://recharts.org/)** - Composable charting library
+- **[React Markdown](https://github.com/remarkjs/react-markdown)** - Markdown rendering with GFM support
 - **[Playwright](https://playwright.dev/)** - End-to-end testing
 
 ### DevOps
@@ -135,12 +234,11 @@ The fastest way to get started is with Docker:
 
 ```bash
 # Clone the repository
-git clone https://github.com/yourusername/fast-next-template.git
+git clone https://github.com/cardosofelipe/pragma-stack.git
 cd fast-next-template
 
-# Copy environment files
-cp backend/.env.example backend/.env
-cp frontend/.env.local.example frontend/.env.local
+# Copy environment file
+cp .env.template .env
 
 # Start all services (backend, frontend, database)
 docker-compose up
@@ -200,17 +298,17 @@ uvicorn app.main:app --reload --host 0.0.0.0 --port 8000
 cd frontend
 
 # Install dependencies
-npm install
+bun install
 
 # Setup environment
 cp .env.local.example .env.local
 # Edit .env.local with your backend URL
 
 # Generate API client
-npm run generate:api
+bun run generate:api
 
 # Start development server
-npm run dev
+bun run dev
 ```
 
 Visit http://localhost:3000 to see your app!
@@ -224,7 +322,7 @@ Visit http://localhost:3000 to see your app!
 │   ├── app/
 │   │   ├── api/            # API routes and dependencies
 │   │   ├── core/           # Core functionality (auth, config, database)
-│   │   ├── crud/           # Database operations
+│   │   ├── repositories/   # Repository pattern (database operations)
 │   │   ├── models/         # SQLAlchemy models
 │   │   ├── schemas/        # Pydantic schemas
 │   │   ├── services/       # Business logic
@@ -279,7 +377,7 @@ open htmlcov/index.html
 ```
 
 **Test types:**
-- **Unit tests**: CRUD operations, utilities, business logic
+- **Unit tests**: Repository operations, utilities, business logic
 - **Integration tests**: API endpoints with database
 - **Security tests**: JWT algorithm attacks, session hijacking, privilege escalation
 - **Error handling tests**: Database failures, validation errors
@@ -292,13 +390,13 @@ open htmlcov/index.html
 cd frontend
 
 # Run unit tests
-npm test
+bun run test
 
 # Run with coverage
-npm run test:coverage
+bun run test:coverage
 
 # Watch mode
-npm run test:watch
+bun run test:watch
 ```
 
 **Test types:**
@@ -316,10 +414,10 @@ npm run test:watch
 cd frontend
 
 # Run E2E tests
-npm run test:e2e
+bun run test:e2e
 
 # Run E2E tests in UI mode (recommended for development)
-npm run test:e2e:ui
+bun run test:e2e:ui
 
 # Run specific test file
 npx playwright test auth-login.spec.ts
@@ -338,6 +436,17 @@ npx playwright show-report
 
 ---
 
+## 🤖 AI-Friendly Documentation
+
+This project includes comprehensive documentation designed for AI coding assistants:
+
+- **[AGENTS.md](./AGENTS.md)** - Framework-agnostic AI assistant context for PragmaStack
+- **[CLAUDE.md](./CLAUDE.md)** - Claude Code-specific guidance
+
+These files provide AI assistants with the **PragmaStack** architecture, patterns, and best practices.
+
+---
+
 ## 🗄️ Database Migrations
 
 The template uses Alembic for database migrations:
@@ -365,22 +474,25 @@ python migrate.py current
 
 ## 📖 Documentation
 
+### AI Assistant Documentation
+
+- **[AGENTS.md](./AGENTS.md)** - Framework-agnostic AI coding assistant context
+- **[CLAUDE.md](./CLAUDE.md)** - Claude Code-specific guidance and preferences
+
 ### Backend Documentation
 
 - **[ARCHITECTURE.md](./backend/docs/ARCHITECTURE.md)** - System architecture and design patterns
 - **[CODING_STANDARDS.md](./backend/docs/CODING_STANDARDS.md)** - Code quality standards
 - **[COMMON_PITFALLS.md](./backend/docs/COMMON_PITFALLS.md)** - Common mistakes to avoid
 - **[FEATURE_EXAMPLE.md](./backend/docs/FEATURE_EXAMPLE.md)** - Step-by-step feature guide
-- **[CLAUDE.md](./CLAUDE.md)** - Comprehensive development guide
 
 ### Frontend Documentation
 
-- **[Design System Docs](./frontend/docs/design-system/)** - Complete design system guide
+- **[PragmaStack Design System](./frontend/docs/design-system/)** - Complete design system guide
   - Quick start, foundations (colors, typography, spacing)
   - Component library guide
   - Layout patterns, spacing philosophy
   - Forms, accessibility, AI guidelines
-- **[ARCHITECTURE_FIX_REPORT.md](./frontend/docs/ARCHITECTURE_FIX_REPORT.md)** - Critical dependency injection patterns
 - **[E2E Testing Guide](./frontend/e2e/README.md)** - E2E testing setup and best practices
 
 ### API Documentation
@@ -429,37 +541,43 @@ docker-compose down
 ## 🛣️ Roadmap & Status
 
 ### ✅ Completed
-- [x] Authentication system (JWT, refresh tokens, session management)
-- [x] User management (CRUD, profile, password change)
+- [x] Authentication system (JWT, refresh tokens, session management, OAuth)
+- [x] User management (full lifecycle, profile, password change)
 - [x] Organization system with RBAC (Owner, Admin, Member)
 - [x] Admin panel (users, organizations, sessions, statistics)
+- [x] **Internationalization (i18n)** with next-intl (English + Italian)
 - [x] Backend testing infrastructure (~97% coverage)
 - [x] Frontend unit testing infrastructure (~97% coverage)
 - [x] Frontend E2E testing (Playwright, zero flaky tests)
 - [x] Design system documentation
-- [x] Database migrations
+- [x] **Marketing landing page** with animated components
+- [x] **`/dev` documentation portal** with live component examples
+- [x] **Toast notifications** system (Sonner)
+- [x] **Charts and visualizations** (Recharts)
+- [x] **Animation system** (Framer Motion)
+- [x] **Markdown rendering** with syntax highlighting
+- [x] **SEO optimization** (sitemap, robots.txt, locale-aware metadata)
+- [x] Database migrations with helper script
 - [x] Docker deployment
 - [x] API documentation (OpenAPI/Swagger)
 
 ### 🚧 In Progress
-- [ ] Frontend admin pages (70% complete)
-- [ ] Dark mode theme
-- [ ] `/dev` documentation page with examples
 - [ ] Email integration (templates ready, SMTP pending)
-- [ ] Chart/visualization components
 
 ### 🔮 Planned
 - [ ] GitHub Actions CI/CD pipelines
 - [ ] Dynamic test coverage badges from CI
 - [ ] E2E test coverage reporting
-- [ ] Additional authentication methods (OAuth, SSO)
+- [ ] OAuth token encryption at rest (security hardening)
+- [ ] Additional languages (Spanish, French, German, etc.)
+- [ ] SSO/SAML authentication
+- [ ] Real-time notifications with WebSockets
 - [ ] Webhook system
-- [ ] Background job processing
-- [ ] File upload/storage
-- [ ] Notification system
-- [ ] Audit logging
+- [ ] File upload/storage (S3-compatible)
+- [ ] Audit logging system
 - [ ] API versioning example
 
+
 ---
 
 ## 🤝 Contributing
@@ -489,7 +607,7 @@ Contributions are welcome! Whether you're fixing bugs, improving documentation,
 
 ### Reporting Issues
 
-Found a bug? Have a suggestion? [Open an issue](https://github.com/yourusername/fast-next-template/issues)!
+Found a bug? Have a suggestion? [Open an issue](https://github.com/cardosofelipe/pragma-stack/issues)!
 
 Please include:
 - Clear description of the issue/suggestion
@@ -523,8 +641,8 @@ This template is built on the shoulders of giants:
 ## 💬 Questions?
 
 - **Documentation**: Check the `/docs` folders in backend and frontend
-- **Issues**: [GitHub Issues](https://github.com/yourusername/fast-next-template/issues)
-- **Discussions**: [GitHub Discussions](https://github.com/yourusername/fast-next-template/discussions)
+- **Issues**: [GitHub Issues](https://github.com/cardosofelipe/pragma-stack/issues)
+- **Discussions**: [GitHub Discussions](https://github.com/cardosofelipe/pragma-stack/discussions)
 
 ---
 

backend/.coveragerc

@@ -11,16 +11,19 @@ omit =
     app/utils/auth_test_utils.py
 
     # Async implementations not yet in use
-    app/crud/base_async.py
+    app/repositories/base_async.py
     app/core/database_async.py
 
+    # CLI scripts - run manually, not tested
+    app/init_db.py
+
     # __init__ files with no logic
     app/__init__.py
     app/api/__init__.py
     app/api/routes/__init__.py
     app/api/dependencies/__init__.py
     app/core/__init__.py
-    app/crud/__init__.py
+    app/repositories/__init__.py
     app/models/__init__.py
     app/schemas/__init__.py
     app/services/__init__.py

backend/.dockerignore

@@ -1,2 +1,17 @@
 .venv
-*.iml
+*.iml
+
+# Python build and cache artifacts
+__pycache__/
+.pytest_cache/
+.mypy_cache/
+.ruff_cache/
+*.pyc
+*.pyo
+
+# Packaging artifacts
+*.egg-info/
+build/
+dist/
+htmlcov/
+.uv_cache/

backend/.pre-commit-config.yaml

@@ -0,0 +1,44 @@
+# Pre-commit hooks for backend quality and security checks.
+#
+# Install:
+#   cd backend && uv run pre-commit install
+#
+# Run manually on all files:
+#   cd backend && uv run pre-commit run --all-files
+#
+# Skip hooks temporarily:
+#   git commit --no-verify
+#
+repos:
+  # ── Code Quality ──────────────────────────────────────────────────────────
+  - repo: https://github.com/astral-sh/ruff-pre-commit
+    rev: v0.14.4
+    hooks:
+      - id: ruff
+        args: [--fix, --exit-non-zero-on-fix]
+      - id: ruff-format
+
+  # ── General File Hygiene ──────────────────────────────────────────────────
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v5.0.0
+    hooks:
+      - id: trailing-whitespace
+      - id: end-of-file-fixer
+      - id: check-yaml
+      - id: check-toml
+      - id: check-merge-conflict
+      - id: check-added-large-files
+        args: [--maxkb=500]
+      - id: debug-statements
+
+  # ── Security ──────────────────────────────────────────────────────────────
+  - repo: https://github.com/Yelp/detect-secrets
+    rev: v1.5.0
+    hooks:
+      - id: detect-secrets
+        args: ['--baseline', '.secrets.baseline']
+        exclude: |
+          (?x)^(
+            .*\.lock$|
+            .*\.svg$
+          )$

backend/Dockerfile

@@ -1,53 +1,67 @@
 # Development stage
 FROM python:3.12-slim AS development
 
-# Create non-root user
-RUN groupadd -r appuser && useradd -r -g appuser appuser
-
 WORKDIR /app
 ENV PYTHONDONTWRITEBYTECODE=1 \
     PYTHONUNBUFFERED=1 \
-    PYTHONPATH=/app
+    PYTHONPATH=/app \
+    UV_COMPILE_BYTECODE=1 \
+    UV_LINK_MODE=copy \
+    UV_NO_CACHE=1
 
+# Install system dependencies and uv
 RUN apt-get update && \
-    apt-get install -y --no-install-recommends gcc postgresql-client curl && \
+    apt-get install -y --no-install-recommends gcc postgresql-client curl ca-certificates && \
+    curl -LsSf https://astral.sh/uv/install.sh | sh && \
+    mv /root/.local/bin/uv* /usr/local/bin/ && \
     apt-get clean && \
     rm -rf /var/lib/apt/lists/*
 
-COPY requirements.txt .
-RUN pip install --no-cache-dir -r requirements.txt
+# Copy dependency files
+COPY pyproject.toml uv.lock ./
 
+# Install dependencies using uv (development mode with dev dependencies)
+RUN uv sync --extra dev --frozen
+
+# Copy application code
 COPY . .
 COPY entrypoint.sh /usr/local/bin/
 RUN chmod +x /usr/local/bin/entrypoint.sh
 
-# Set ownership to non-root user
-RUN chown -R appuser:appuser /app
-
-# Switch to non-root user
-USER appuser
+# Note: Running as root in development for bind mount compatibility
+# Production stage uses non-root user for security
 
 ENTRYPOINT ["/usr/local/bin/entrypoint.sh"]
 
-# Production stage
-FROM python:3.12-slim AS production
+# Production stage — Alpine eliminates glibc CVEs (e.g. CVE-2026-0861)
+FROM python:3.12-alpine AS production
 
 # Create non-root user
-RUN groupadd -r appuser && useradd -r -g appuser appuser
+RUN addgroup -S appuser && adduser -S -G appuser appuser
 
 WORKDIR /app
 ENV PYTHONDONTWRITEBYTECODE=1 \
     PYTHONUNBUFFERED=1 \
-    PYTHONPATH=/app
+    PYTHONPATH=/app \
+    UV_COMPILE_BYTECODE=1 \
+    UV_LINK_MODE=copy \
+    UV_NO_CACHE=1
 
-RUN apt-get update && \
-    apt-get install -y --no-install-recommends postgresql-client curl && \
-    apt-get clean && \
-    rm -rf /var/lib/apt/lists/*
+# Install system dependencies and uv
+RUN apk add --no-cache postgresql-client curl ca-certificates && \
+    curl -LsSf https://astral.sh/uv/install.sh | sh && \
+    mv /root/.local/bin/uv* /usr/local/bin/
 
-COPY requirements.txt .
-RUN pip install --no-cache-dir -r requirements.txt
+# Copy dependency files
+COPY pyproject.toml uv.lock ./
 
+# Install build dependencies, compile Python packages, then remove build deps
+RUN apk add --no-cache --virtual .build-deps \
+        gcc g++ musl-dev python3-dev linux-headers libffi-dev openssl-dev && \
+    uv sync --frozen --no-dev && \
+    apk del .build-deps
+
+# Copy application code
 COPY . .
 COPY entrypoint.sh /usr/local/bin/
 RUN chmod +x /usr/local/bin/entrypoint.sh
@@ -63,4 +77,4 @@ HEALTHCHECK --interval=30s --timeout=10s --start-period=40s --retries=3 \
     CMD curl -f http://localhost:8000/health || exit 1
 
 ENTRYPOINT ["/usr/local/bin/entrypoint.sh"]
-CMD ["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "8000"]
+CMD ["uv", "run", "uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "8000"]

backend/Makefile

@@ -0,0 +1,220 @@
+.PHONY: help lint lint-fix format format-check type-check test test-cov validate clean install-dev sync check-docker install-e2e test-e2e test-e2e-schema test-all dep-audit license-check audit validate-all check benchmark benchmark-check benchmark-save scan-image test-api-security
+
+# Prevent a stale VIRTUAL_ENV in the caller's shell from confusing uv
+unexport VIRTUAL_ENV
+
+# Default target
+help:
+	@echo "🚀 FastAPI Backend - Development Commands"
+	@echo ""
+	@echo "Setup:"
+	@echo "  make install-dev   - Install all dependencies with uv (includes dev)"
+	@echo "  make install-e2e   - Install E2E test dependencies (requires Docker)"
+	@echo "  make sync          - Sync dependencies from uv.lock"
+	@echo ""
+	@echo "Quality Checks:"
+	@echo "  make lint          - Run Ruff linter (check only)"
+	@echo "  make lint-fix      - Run Ruff linter with auto-fix"
+	@echo "  make format        - Format code with Ruff"
+	@echo "  make format-check  - Check if code is formatted"
+	@echo "  make type-check    - Run pyright type checking"
+	@echo "  make validate      - Run all checks (lint + format + types + schema fuzz)"
+	@echo ""
+	@echo "Performance:"
+	@echo "  make benchmark       - Run performance benchmarks"
+	@echo "  make benchmark-save  - Run benchmarks and save as baseline"
+	@echo "  make benchmark-check - Run benchmarks and compare against baseline"
+	@echo ""
+	@echo "Security & Audit:"
+	@echo "  make dep-audit     - Scan dependencies for known vulnerabilities"
+	@echo "  make license-check - Check dependency license compliance"
+	@echo "  make audit         - Run all security audits (deps + licenses)"
+	@echo "  make scan-image    - Scan Docker image for CVEs (requires trivy)"
+	@echo "  make validate-all  - Run all quality + security checks"
+	@echo "  make check         - Full pipeline: quality + security + tests"
+	@echo ""
+	@echo "Testing:"
+	@echo "  make test          - Run pytest (unit/integration, SQLite)"
+	@echo "  make test-cov      - Run pytest with coverage report"
+	@echo "  make test-e2e      - Run E2E tests (PostgreSQL, requires Docker)"
+	@echo "  make test-e2e-schema - Run Schemathesis API schema tests"
+	@echo "  make test-all      - Run all tests (unit + E2E)"
+	@echo "  make check-docker  - Check if Docker is available"
+	@echo "  make check         - Full pipeline: quality + security + tests"
+	@echo ""
+	@echo "Cleanup:"
+	@echo "  make clean         - Remove cache and build artifacts"
+
+# ============================================================================
+# Setup & Cleanup
+# ============================================================================
+
+install-dev:
+	@echo "📦 Installing all dependencies with uv (includes dev)..."
+	@uv sync --extra dev
+	@echo "✅ Development environment ready!"
+
+sync:
+	@echo "🔄 Syncing dependencies from uv.lock..."
+	@uv sync --extra dev
+	@echo "✅ Dependencies synced!"
+
+# ============================================================================
+# Code Quality
+# ============================================================================
+
+lint:
+	@echo "🔍 Running Ruff linter..."
+	@uv run ruff check app/ tests/
+
+lint-fix:
+	@echo "🔧 Running Ruff linter with auto-fix..."
+	@uv run ruff check --fix app/ tests/
+
+format:
+	@echo "✨ Formatting code with Ruff..."
+	@uv run ruff format app/ tests/
+
+format-check:
+	@echo "📋 Checking code formatting..."
+	@uv run ruff format --check app/ tests/
+
+type-check:
+	@echo "🔎 Running pyright type checking..."
+	@uv run pyright app/
+
+validate: lint format-check type-check test-api-security
+	@echo "✅ All quality checks passed!"
+
+# API Security Testing (Schemathesis property-based fuzzing)
+test-api-security: check-docker
+	@echo "🔐 Running Schemathesis API security fuzzing..."
+	@IS_TEST=True PYTHONPATH=. uv run pytest tests/e2e/ -v -m "schemathesis" --tb=short -n 0
+	@echo "✅ API schema security tests passed!"
+
+# ============================================================================
+# Security & Audit
+# ============================================================================
+
+dep-audit:
+	@echo "🔒 Scanning dependencies for known vulnerabilities..."
+	@uv run pip-audit --desc --skip-editable
+	@echo "✅ No known vulnerabilities found!"
+
+license-check:
+	@echo "📜 Checking dependency license compliance..."
+	@uv run pip-licenses --fail-on="GPL-3.0-or-later;AGPL-3.0-or-later" --format=plain > /dev/null
+	@echo "✅ All dependency licenses are compliant!"
+
+audit: dep-audit license-check
+	@echo "✅ All security audits passed!"
+
+scan-image: check-docker
+	@echo "🐳 Scanning Docker image for OS-level CVEs with Trivy..."
+	@docker build -t pragma-backend:scan -q --target production .
+	@if command -v trivy > /dev/null 2>&1; then \
+		trivy image --severity HIGH,CRITICAL --exit-code 1 pragma-backend:scan; \
+	else \
+		echo "ℹ️  Trivy not found locally, using Docker to run Trivy..."; \
+		docker run --rm -v /var/run/docker.sock:/var/run/docker.sock aquasec/trivy image --severity HIGH,CRITICAL --exit-code 1 pragma-backend:scan; \
+	fi
+	@echo "✅ No HIGH/CRITICAL CVEs found in Docker image!"
+
+validate-all: validate audit
+	@echo "✅ All quality + security checks passed!"
+
+check: validate-all test
+	@echo "✅ Full validation pipeline complete!"
+
+# ============================================================================
+# Testing
+# ============================================================================
+
+test:
+	@echo "🧪 Running tests..."
+	@IS_TEST=True PYTHONPATH=. uv run pytest
+
+test-cov:
+	@echo "🧪 Running tests with coverage..."
+	@IS_TEST=True PYTHONPATH=. uv run pytest --cov=app --cov-report=term-missing --cov-report=html -n 16
+	@echo "📊 Coverage report generated in htmlcov/index.html"
+
+# ============================================================================
+# E2E Testing (requires Docker)
+# ============================================================================
+
+check-docker:
+	@docker info > /dev/null 2>&1 || (echo ""; \
+		echo "Docker is not running!"; \
+		echo ""; \
+		echo "E2E tests require Docker to be running."; \
+		echo "Please start Docker Desktop or Docker Engine and try again."; \
+		echo ""; \
+		echo "Quick start:"; \
+		echo "  macOS/Windows: Open Docker Desktop"; \
+		echo "  Linux: sudo systemctl start docker"; \
+		echo ""; \
+		exit 1)
+	@echo "Docker is available"
+
+install-e2e:
+	@echo "📦 Installing E2E test dependencies..."
+	@uv sync --extra dev --extra e2e
+	@echo "✅ E2E dependencies installed!"
+
+test-e2e: check-docker
+	@echo "🧪 Running E2E tests with PostgreSQL..."
+	@IS_TEST=True PYTHONPATH=. uv run pytest tests/e2e/ -v --tb=short -n 0
+	@echo "✅ E2E tests complete!"
+
+test-e2e-schema: check-docker
+	@echo "🧪 Running Schemathesis API schema tests..."
+	@IS_TEST=True PYTHONPATH=. uv run pytest tests/e2e/ -v -m "schemathesis" --tb=short -n 0
+
+# ============================================================================
+# Performance Benchmarks
+# ============================================================================
+
+benchmark:
+	@echo "⏱️  Running performance benchmarks..."
+	@IS_TEST=True PYTHONPATH=. uv run pytest tests/benchmarks/ -v --benchmark-only --benchmark-sort=mean -p no:xdist --override-ini='addopts='
+
+benchmark-save:
+	@echo "⏱️  Running benchmarks and saving baseline..."
+	@IS_TEST=True PYTHONPATH=. uv run pytest tests/benchmarks/ -v --benchmark-only --benchmark-save=baseline --benchmark-sort=mean -p no:xdist --override-ini='addopts='
+	@echo "✅ Benchmark baseline saved to .benchmarks/"
+
+benchmark-check:
+	@echo "⏱️  Running benchmarks and comparing against baseline..."
+	@if find .benchmarks -name '*_baseline*' -print -quit 2>/dev/null | grep -q .; then \
+		IS_TEST=True PYTHONPATH=. uv run pytest tests/benchmarks/ -v --benchmark-only --benchmark-compare=0001_baseline --benchmark-sort=mean --benchmark-compare-fail=mean:200% -p no:xdist --override-ini='addopts='; \
+		echo "✅ No performance regressions detected!"; \
+	else \
+		echo "⚠️  No benchmark baseline found. Run 'make benchmark-save' first to create one."; \
+		echo "   Running benchmarks without comparison..."; \
+		IS_TEST=True PYTHONPATH=. uv run pytest tests/benchmarks/ -v --benchmark-only --benchmark-save=baseline --benchmark-sort=mean -p no:xdist --override-ini='addopts='; \
+		echo "✅ Benchmark baseline created. Future runs of 'make benchmark-check' will compare against it."; \
+	fi
+
+test-all:
+	@echo "🧪 Running ALL tests (unit + E2E)..."
+	@$(MAKE) test
+	@$(MAKE) test-e2e
+
+# ============================================================================
+# Cleanup
+# ============================================================================
+
+clean:
+	@echo "🧹 Cleaning up..."
+	@find . -type d -name "__pycache__" -exec rm -rf {} + 2>/dev/null || true
+	@find . -type d -name ".pytest_cache" -exec rm -rf {} + 2>/dev/null || true
+	@find . -type d -name ".pyright" -exec rm -rf {} + 2>/dev/null || true
+	@find . -type d -name ".ruff_cache" -exec rm -rf {} + 2>/dev/null || true
+	@find . -type d -name "*.egg-info" -exec rm -rf {} + 2>/dev/null || true
+	@find . -type d -name "htmlcov" -exec rm -rf {} + 2>/dev/null || true
+	@find . -type d -name "build" -exec rm -rf {} + 2>/dev/null || true
+	@find . -type d -name ".uv_cache" -exec rm -rf {} + 2>/dev/null || true
+	@find . -type f -name ".coverage" -delete 2>/dev/null || true
+	@find . -type f -name "*.pyc" -delete 2>/dev/null || true
+	@echo "✅ Cleanup complete!"

backend/README.md

@@ -1,10 +1,12 @@
-# Backend API
+# PragmaStack Backend API
 
-> FastAPI-based REST API with async SQLAlchemy, JWT authentication, and comprehensive testing.
+> The pragmatic, production-ready FastAPI backend for PragmaStack.
 
 ## Overview
 
-Production-ready FastAPI backend featuring:
+Opinionated, secure, and fast. This backend provides the solid foundation you need to ship features, not boilerplate.
+
+Features:
 
 - **Authentication**: JWT with refresh tokens, session management, device tracking
 - **Database**: Async PostgreSQL with SQLAlchemy 2.0, Alembic migrations
@@ -12,30 +14,42 @@ Production-ready FastAPI backend featuring:
 - **Multi-tenancy**: Organization-based access control with roles (Owner/Admin/Member)
 - **Testing**: 97%+ coverage with security-focused test suite
 - **Performance**: Async throughout, connection pooling, optimized queries
+- **Modern Tooling**: uv for dependencies, Ruff for linting/formatting, Pyright for type checking
+- **Security Auditing**: Automated dependency vulnerability scanning, license compliance, secrets detection
+- **Pre-commit Hooks**: Ruff, detect-secrets, and standard checks on every commit
 
 ## Quick Start
 
 ### Prerequisites
 
-- Python 3.11+
+- Python 3.12+
 - PostgreSQL 14+ (or SQLite for development)
-- pip and virtualenv
+- **[uv](https://docs.astral.sh/uv/)** - Modern Python package manager (replaces pip)
 
 ### Installation
 
 ```bash
-# Create virtual environment
-python -m venv .venv
-source .venv/bin/activate  # On Windows: .venv\Scripts\activate
+# Install uv (if not already installed)
+curl -LsSf https://astral.sh/uv/install.sh | sh
 
-# Install dependencies
-pip install -r requirements.txt
+# Install all dependencies (production + dev)
+cd backend
+uv sync --extra dev
+
+# Or use the Makefile
+make install-dev
 
 # Copy environment template
 cp .env.example .env
 # Edit .env with your configuration
 ```
 
+**Why uv?**
+- 🚀 10-100x faster than pip
+- 🔒 Reproducible builds via `uv.lock` lockfile
+- 📦 Better dependency resolution
+- ⚡ Built by Astral (creators of Ruff)
+
 ### Database Setup
 
 ```bash
@@ -49,6 +63,11 @@ alembic upgrade head
 ### Run Development Server
 
 ```bash
+# Using uv
+uv run uvicorn app.main:app --reload --host 0.0.0.0 --port 8000
+
+# Or activate environment first
+source .venv/bin/activate  # On Windows: .venv\Scripts\activate
 uvicorn app.main:app --reload --host 0.0.0.0 --port 8000
 ```
 
@@ -57,6 +76,180 @@ API will be available at:
 - **Swagger Docs**: http://localhost:8000/docs
 - **ReDoc**: http://localhost:8000/redoc
 
+---
+
+## Dependency Management with uv
+
+### Understanding uv
+
+**uv** is the modern standard for Python dependency management, built in Rust for speed and reliability.
+
+**Key files:**
+- `pyproject.toml` - Declares dependencies and tool configurations
+- `uv.lock` - Locks exact versions for reproducible builds (commit to git)
+
+### Common Commands
+
+#### Installing Dependencies
+
+```bash
+# Install all dependencies from lockfile
+uv sync --extra dev
+
+# Install only production dependencies (no dev tools)
+uv sync
+
+# Or use the Makefile
+make install-dev    # Install with dev dependencies
+make sync           # Sync from lockfile
+```
+
+#### Adding Dependencies
+
+```bash
+# Add a production dependency
+uv add httpx
+
+# Add a development dependency
+uv add --dev pytest-mock
+
+# Add with version constraint
+uv add "fastapi>=0.115.0,<0.116.0"
+
+# Add exact version
+uv add "pydantic==2.10.6"
+```
+
+After adding dependencies, **commit both `pyproject.toml` and `uv.lock`** to git.
+
+#### Removing Dependencies
+
+```bash
+# Remove a package
+uv remove httpx
+
+# Remove a dev dependency
+uv remove --dev pytest-mock
+```
+
+#### Updating Dependencies
+
+```bash
+# Update all packages to latest compatible versions
+uv sync --upgrade
+
+# Update a specific package
+uv add --upgrade fastapi
+
+# Check for outdated packages
+uv pip list --outdated
+```
+
+#### Running Commands in uv Environment
+
+```bash
+# Run any Python command via uv (no activation needed)
+uv run python script.py
+uv run pytest
+uv run pyright app/
+
+# Or activate the virtual environment
+source .venv/bin/activate
+python script.py
+pytest
+```
+
+### Makefile Commands
+
+We provide convenient Makefile commands that use uv:
+
+```bash
+# Setup
+make install-dev   # Install all dependencies (prod + dev)
+make sync          # Sync from lockfile
+
+# Code Quality
+make lint          # Run Ruff linter (check only)
+make lint-fix      # Run Ruff with auto-fix
+make format        # Format code with Ruff
+make format-check  # Check if code is formatted
+make type-check    # Run Pyright type checking
+make validate      # Run all checks (lint + format + types)
+
+# Security & Audit
+make dep-audit     # Scan dependencies for known vulnerabilities (CVEs)
+make license-check # Check dependency license compliance
+make audit         # Run all security audits (deps + licenses)
+make validate-all  # Run all quality + security checks
+make check         # Full pipeline: quality + security + tests
+
+# Testing
+make test          # Run all tests
+make test-cov      # Run tests with coverage report
+make test-e2e      # Run E2E tests (PostgreSQL, requires Docker)
+make test-e2e-schema # Run Schemathesis API schema tests
+make test-all      # Run all tests (unit + E2E)
+
+# Utilities
+make clean         # Remove cache and build artifacts
+make help          # Show all commands
+```
+
+### Dependency Workflow Example
+
+```bash
+# 1. Clone repository
+git clone <repo-url>
+cd backend
+
+# 2. Install dependencies
+make install-dev
+
+# 3. Make changes, add a new dependency
+uv add httpx
+
+# 4. Test your changes
+make test
+
+# 5. Commit (includes uv.lock)
+git add pyproject.toml uv.lock
+git commit -m "Add httpx dependency"
+
+# 6. Other developers pull and sync
+git pull
+make sync  # Uses the committed uv.lock
+```
+
+### Troubleshooting uv
+
+**Dependencies not found after install:**
+```bash
+# Make sure you're using uv run or activated environment
+uv run pytest          # Option 1: Run via uv
+source .venv/bin/activate  # Option 2: Activate first
+pytest
+```
+
+**Lockfile out of sync:**
+```bash
+# Regenerate lockfile
+uv lock
+
+# Force reinstall from lockfile
+uv sync --reinstall
+```
+
+**uv not found:**
+```bash
+# Install uv globally
+curl -LsSf https://astral.sh/uv/install.sh | sh
+
+# Add to PATH if needed
+export PATH="$HOME/.cargo/bin:$PATH"
+```
+
+---
+
 ## Development
 
 ### Project Structure
@@ -71,7 +264,7 @@ app/
 │   ├── database.py   # Database engine setup
 │   ├── auth.py       # JWT token handling
 │   └── exceptions.py # Custom exceptions
-├── crud/             # Database operations
+├── repositories/     # Repository pattern (database operations)
 ├── models/           # SQLAlchemy ORM models
 ├── schemas/          # Pydantic request/response schemas
 ├── services/         # Business logic layer
@@ -144,20 +337,22 @@ alembic downgrade -1
 ### Testing
 
 ```bash
-# Run all tests
-IS_TEST=True pytest
+# Using Makefile (recommended)
+make test              # Run all tests
+make test-cov          # Run with coverage report
 
-# Run with coverage
-IS_TEST=True pytest --cov=app --cov-report=term-missing -n 0
+# Using uv directly
+IS_TEST=True uv run pytest
+IS_TEST=True uv run pytest --cov=app --cov-report=term-missing -n 0
 
 # Run specific test file
-IS_TEST=True pytest tests/api/test_auth.py -v
+IS_TEST=True uv run pytest tests/api/test_auth.py -v
 
 # Run single test
-IS_TEST=True pytest tests/api/test_auth.py::TestLogin::test_login_success -v
+IS_TEST=True uv run pytest tests/api/test_auth.py::TestLogin::test_login_success -v
 
 # Generate HTML coverage report
-IS_TEST=True pytest --cov=app --cov-report=html -n 0
+IS_TEST=True uv run pytest --cov=app --cov-report=html -n 0
 open htmlcov/index.html
 ```
 
@@ -166,17 +361,37 @@ open htmlcov/index.html
 ### Code Quality
 
 ```bash
-# Type checking
-mypy app
+# Using Makefile (recommended)
+make lint          # Ruff linting
+make format        # Ruff formatting
+make type-check    # Pyright type checking
+make validate      # All checks at once
 
-# Linting
-ruff check app
+# Security audits
+make dep-audit     # Scan dependencies for CVEs
+make license-check # Check license compliance
+make audit         # All security audits
+make validate-all  # Quality + security checks
+make check         # Full pipeline: quality + security + tests
 
-# Format code
-black app
-isort app
+# Using uv directly
+uv run ruff check app/ tests/
+uv run ruff format app/ tests/
+uv run pyright app/
 ```
 
+**Tools:**
+- **Ruff**: All-in-one linting, formatting, and import sorting (replaces Black, Flake8, isort)
+- **Pyright**: Static type checking (strict mode)
+- **pip-audit**: Dependency vulnerability scanning against the OSV database
+- **pip-licenses**: Dependency license compliance checking
+- **detect-secrets**: Hardcoded secrets/credentials detection
+- **pre-commit**: Git hook framework for automated checks on every commit
+
+All configurations are in `pyproject.toml`.
+
+---
+
 ## API Documentation
 
 Once the server is running, interactive API documentation is available:
@@ -194,6 +409,8 @@ Once the server is running, interactive API documentation is available:
   - Raw OpenAPI 3.0 specification
   - Use for client generation
 
+---
+
 ## Authentication
 
 ### Token-Based Authentication
@@ -229,6 +446,8 @@ curl -H "Authorization: Bearer <access_token>" \
   - `Admin`: Can manage members (except owners)
   - `Member`: Read-only access
 
+---
+
 ## Common Tasks
 
 ### Create a Superuser
@@ -243,7 +462,7 @@ See [docs/FEATURE_EXAMPLE.md](docs/FEATURE_EXAMPLE.md) for step-by-step guide.
 
 Quick overview:
 1. Create Pydantic schemas in `app/schemas/`
-2. Create CRUD operations in `app/crud/`
+2. Create repository in `app/repositories/`
 3. Create route in `app/api/routes/`
 4. Register router in `app/api/main.py`
 5. Write tests in `tests/api/`
@@ -258,8 +477,12 @@ python migrate.py check
 curl http://localhost:8000/health
 ```
 
+---
+
 ## Docker Support
 
+The Dockerfile uses **uv** for fast, reproducible builds:
+
 ```bash
 # Development with hot reload
 docker-compose -f docker-compose.dev.yml up
@@ -271,17 +494,38 @@ docker-compose up -d
 docker-compose build backend
 ```
 
+**Docker features:**
+- Multi-stage builds (development + production)
+- uv for fast dependency installation
+- `uv.lock` ensures exact versions in containers
+- Development stage includes dev dependencies
+- Production stage optimized for size and security
+
+---
+
 ## Troubleshooting
 
 ### Common Issues
 
 **Module Import Errors**
 ```bash
-# Ensure you're in the backend directory
-cd backend
+# Ensure dependencies are installed
+make install-dev
 
-# Activate virtual environment
-source .venv/bin/activate
+# Or sync from lockfile
+make sync
+
+# Verify Python environment
+uv run python --version
+```
+
+**uv command not found**
+```bash
+# Install uv globally
+curl -LsSf https://astral.sh/uv/install.sh | sh
+
+# Add to PATH (add to ~/.bashrc or ~/.zshrc)
+export PATH="$HOME/.cargo/bin:$PATH"
 ```
 
 **Database Connection Failed**
@@ -306,10 +550,19 @@ alembic upgrade head
 **Tests Failing**
 ```bash
 # Run with verbose output
-IS_TEST=True pytest -vv
+make test
 
 # Run single test to isolate issue
-IS_TEST=True pytest tests/api/test_auth.py::TestLogin::test_login_success -vv
+IS_TEST=True uv run pytest tests/api/test_auth.py::TestLogin::test_login_success -vv
+```
+
+**Dependencies out of sync**
+```bash
+# Regenerate lockfile from pyproject.toml
+uv lock
+
+# Reinstall everything
+make install-dev
 ```
 
 ### Getting Help
@@ -321,6 +574,8 @@ See our detailed documentation:
 - [COMMON_PITFALLS.md](docs/COMMON_PITFALLS.md) - Mistakes to avoid
 - [FEATURE_EXAMPLE.md](docs/FEATURE_EXAMPLE.md) - Adding new features
 
+---
+
 ## Performance
 
 ### Database Connection Pooling
@@ -343,6 +598,8 @@ Configured in `app/core/config.py`:
 - Bulk operations for admin actions
 - Indexed foreign keys and common lookups
 
+---
+
 ## Security
 
 ### Built-in Security Features
@@ -355,13 +612,44 @@ Configured in `app/core/config.py`:
 - **Security Headers**: CSP, HSTS, X-Frame-Options, etc.
 - **Input Validation**: Pydantic schemas, SQL injection prevention (ORM)
 
+### Security Auditing
+
+Automated, deterministic security checks are built into the development workflow:
+
+```bash
+# Scan dependencies for known vulnerabilities (CVEs)
+make dep-audit
+
+# Check dependency license compliance (blocks GPL-3.0/AGPL)
+make license-check
+
+# Run all security audits
+make audit
+
+# Full pipeline: quality + security + tests
+make check
+```
+
+**Pre-commit hooks** automatically run on every commit:
+- **Ruff** lint + format checks
+- **detect-secrets** blocks commits containing hardcoded secrets
+- **Standard checks**: trailing whitespace, YAML/TOML validation, merge conflict detection, large file prevention
+
+Setup pre-commit hooks:
+```bash
+uv run pre-commit install
+```
+
 ### Security Best Practices
 
-1. **Never commit secrets**: Use `.env` files (git-ignored)
+1. **Never commit secrets**: Use `.env` files (git-ignored), enforced by detect-secrets pre-commit hook
 2. **Strong SECRET_KEY**: Min 32 chars, cryptographically random
 3. **HTTPS in production**: Required for token security
-4. **Regular updates**: Keep dependencies current
+4. **Regular updates**: Keep dependencies current (`uv sync --upgrade`), run `make dep-audit` to check for CVEs
 5. **Audit logs**: Monitor authentication events
+6. **Run `make check` before pushing**: Validates quality, security, and tests in one command
+
+---
 
 ## Monitoring
 
@@ -388,13 +676,32 @@ logging.basicConfig(level=logging.INFO)
 # In production, use JSON logs for log aggregation
 ```
 
+---
+
 ## Additional Resources
 
-- **FastAPI Documentation**: https://fastapi.tiangolo.com
+### Official Documentation
+- **uv**: https://docs.astral.sh/uv/
+- **FastAPI**: https://fastapi.tiangolo.com
 - **SQLAlchemy 2.0**: https://docs.sqlalchemy.org/en/20/
 - **Pydantic**: https://docs.pydantic.dev/
 - **Alembic**: https://alembic.sqlalchemy.org/
+- **Ruff**: https://docs.astral.sh/ruff/
+
+### Our Documentation
+- [Root README](../README.md) - Project-wide information
+- [CLAUDE.md](../CLAUDE.md) - Comprehensive development guide
 
 ---
 
-**Note**: For project-wide information (license, contributing guidelines, deployment), see the [root README](../README.md).
+**Built with modern Python tooling:**
+- 🚀 **uv** - 10-100x faster dependency management
+- ⚡ **Ruff** - 10-100x faster linting & formatting
+- 🔍 **Pyright** - Static type checking (strict mode)
+- ✅ **pytest** - Comprehensive test suite
+- 🔒 **pip-audit** - Dependency vulnerability scanning
+- 🔑 **detect-secrets** - Hardcoded secrets detection
+- 📜 **pip-licenses** - License compliance checking
+- 🪝 **pre-commit** - Automated git hooks
+
+**All configured in a single `pyproject.toml` file!**

backend/alembic.ini

@@ -2,6 +2,13 @@
 script_location = app/alembic
 sqlalchemy.url = postgresql://postgres:postgres@db:5432/app
 
+# Use sequential naming: 0001_message.py, 0002_message.py, etc.
+# The rev_id is still used internally but filename is cleaner
+file_template = %%(rev)s_%%(slug)s
+
+# Allow specifying custom revision IDs via --rev-id flag
+revision_environment = true
+
 [loggers]
 keys = root,sqlalchemy,alembic
 

backend/app/alembic/env.py

@@ -2,12 +2,11 @@ import sys
 from logging.config import fileConfig
 from pathlib import Path
 
-from sqlalchemy import engine_from_config, pool, text, create_engine
+from alembic import context
+from sqlalchemy import create_engine, engine_from_config, pool, text
 from sqlalchemy.engine.url import make_url
 from sqlalchemy.exc import OperationalError
 
-from alembic import context
-
 # Get the path to the app directory (parent of 'alembic')
 app_dir = Path(__file__).resolve().parent.parent
 # Add the app directory to Python path
@@ -23,6 +22,25 @@ from app.models import *
 # access to the values within the .ini file in use.
 config = context.config
 
+
+def include_object(object, name, type_, reflected, compare_to):
+    """
+    Filter objects for autogenerate.
+
+    Skip comparing functional indexes (like LOWER(column)) and partial indexes
+    (with WHERE clauses) as Alembic cannot reliably detect these from models.
+    These should be managed manually via dedicated performance migrations.
+
+    Convention: Any index starting with "ix_perf_" is automatically excluded.
+    This allows adding new performance indexes without updating this file.
+    """
+    if type_ == "index" and name:
+        # Convention-based: any index prefixed with ix_perf_ is manual
+        if name.startswith("ix_perf_"):
+            return False
+    return True
+
+
 # Interpret the config file for Python logging.
 # This line sets up loggers basically.
 if config.config_file_name is not None:
@@ -66,7 +84,9 @@ def ensure_database_exists(db_url: str) -> None:
     admin_url = url.set(database="postgres")
 
     # CREATE DATABASE cannot run inside a transaction
-    admin_engine = create_engine(str(admin_url), isolation_level="AUTOCOMMIT", poolclass=pool.NullPool)
+    admin_engine = create_engine(
+        str(admin_url), isolation_level="AUTOCOMMIT", poolclass=pool.NullPool
+    )
     try:
         with admin_engine.connect() as conn:
             exists = conn.execute(
@@ -99,6 +119,8 @@ def run_migrations_offline() -> None:
         target_metadata=target_metadata,
         literal_binds=True,
         dialect_opts={"paramstyle": "named"},
+        compare_type=True,
+        include_object=include_object,
     )
 
     with context.begin_transaction():
@@ -123,7 +145,10 @@ def run_migrations_online() -> None:
 
     with connectable.connect() as connection:
         context.configure(
-            connection=connection, target_metadata=target_metadata
+            connection=connection,
+            target_metadata=target_metadata,
+            compare_type=True,
+            include_object=include_object,
         )
 
         with context.begin_transaction():
@@ -133,4 +158,4 @@ def run_migrations_online() -> None:
 if context.is_offline_mode():
     run_migrations_offline()
 else:
-    run_migrations_online()
+    run_migrations_online()

backend/app/alembic/versions/0001_initial_models.py

@@ -0,0 +1,446 @@
+"""initial models
+
+Revision ID: 0001
+Revises:
+Create Date: 2025-11-27 09:08:09.464506
+
+"""
+
+from collections.abc import Sequence
+
+import sqlalchemy as sa
+from alembic import op
+from sqlalchemy.dialects import postgresql
+
+# revision identifiers, used by Alembic.
+revision: str = "0001"
+down_revision: str | None = None
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
+
+
+def upgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_table(
+        "oauth_states",
+        sa.Column("state", sa.String(length=255), nullable=False),
+        sa.Column("code_verifier", sa.String(length=128), nullable=True),
+        sa.Column("nonce", sa.String(length=255), nullable=True),
+        sa.Column("provider", sa.String(length=50), nullable=False),
+        sa.Column("redirect_uri", sa.String(length=500), nullable=True),
+        sa.Column("user_id", sa.UUID(), nullable=True),
+        sa.Column("expires_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("id", sa.UUID(), nullable=False),
+        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=False),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_index(
+        op.f("ix_oauth_states_state"), "oauth_states", ["state"], unique=True
+    )
+    op.create_table(
+        "organizations",
+        sa.Column("name", sa.String(length=255), nullable=False),
+        sa.Column("slug", sa.String(length=255), nullable=False),
+        sa.Column("description", sa.Text(), nullable=True),
+        sa.Column("is_active", sa.Boolean(), nullable=False),
+        sa.Column("settings", postgresql.JSONB(astext_type=sa.Text()), nullable=True),
+        sa.Column("id", sa.UUID(), nullable=False),
+        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=False),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_index(
+        op.f("ix_organizations_is_active"), "organizations", ["is_active"], unique=False
+    )
+    op.create_index(
+        op.f("ix_organizations_name"), "organizations", ["name"], unique=False
+    )
+    op.create_index(
+        "ix_organizations_name_active",
+        "organizations",
+        ["name", "is_active"],
+        unique=False,
+    )
+    op.create_index(
+        op.f("ix_organizations_slug"), "organizations", ["slug"], unique=True
+    )
+    op.create_index(
+        "ix_organizations_slug_active",
+        "organizations",
+        ["slug", "is_active"],
+        unique=False,
+    )
+    op.create_table(
+        "users",
+        sa.Column("email", sa.String(length=255), nullable=False),
+        sa.Column("password_hash", sa.String(length=255), nullable=True),
+        sa.Column("first_name", sa.String(length=100), nullable=False),
+        sa.Column("last_name", sa.String(length=100), nullable=True),
+        sa.Column("phone_number", sa.String(length=20), nullable=True),
+        sa.Column("is_active", sa.Boolean(), nullable=False),
+        sa.Column("is_superuser", sa.Boolean(), nullable=False),
+        sa.Column(
+            "preferences", postgresql.JSONB(astext_type=sa.Text()), nullable=True
+        ),
+        sa.Column("locale", sa.String(length=10), nullable=True),
+        sa.Column("deleted_at", sa.DateTime(timezone=True), nullable=True),
+        sa.Column("id", sa.UUID(), nullable=False),
+        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=False),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_index(op.f("ix_users_deleted_at"), "users", ["deleted_at"], unique=False)
+    op.create_index(op.f("ix_users_email"), "users", ["email"], unique=True)
+    op.create_index(op.f("ix_users_is_active"), "users", ["is_active"], unique=False)
+    op.create_index(
+        op.f("ix_users_is_superuser"), "users", ["is_superuser"], unique=False
+    )
+    op.create_index(op.f("ix_users_locale"), "users", ["locale"], unique=False)
+    op.create_table(
+        "oauth_accounts",
+        sa.Column("user_id", sa.UUID(), nullable=False),
+        sa.Column("provider", sa.String(length=50), nullable=False),
+        sa.Column("provider_user_id", sa.String(length=255), nullable=False),
+        sa.Column("provider_email", sa.String(length=255), nullable=True),
+        sa.Column("access_token_encrypted", sa.String(length=2048), nullable=True),
+        sa.Column("refresh_token_encrypted", sa.String(length=2048), nullable=True),
+        sa.Column("token_expires_at", sa.DateTime(timezone=True), nullable=True),
+        sa.Column("id", sa.UUID(), nullable=False),
+        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=False),
+        sa.ForeignKeyConstraint(["user_id"], ["users.id"], ondelete="CASCADE"),
+        sa.PrimaryKeyConstraint("id"),
+        sa.UniqueConstraint(
+            "provider", "provider_user_id", name="uq_oauth_provider_user"
+        ),
+    )
+    op.create_index(
+        op.f("ix_oauth_accounts_provider"), "oauth_accounts", ["provider"], unique=False
+    )
+    op.create_index(
+        op.f("ix_oauth_accounts_provider_email"),
+        "oauth_accounts",
+        ["provider_email"],
+        unique=False,
+    )
+    op.create_index(
+        op.f("ix_oauth_accounts_user_id"), "oauth_accounts", ["user_id"], unique=False
+    )
+    op.create_index(
+        "ix_oauth_accounts_user_provider",
+        "oauth_accounts",
+        ["user_id", "provider"],
+        unique=False,
+    )
+    op.create_table(
+        "oauth_clients",
+        sa.Column("client_id", sa.String(length=64), nullable=False),
+        sa.Column("client_secret_hash", sa.String(length=255), nullable=True),
+        sa.Column("client_name", sa.String(length=255), nullable=False),
+        sa.Column("client_description", sa.String(length=1000), nullable=True),
+        sa.Column("client_type", sa.String(length=20), nullable=False),
+        sa.Column(
+            "redirect_uris", postgresql.JSONB(astext_type=sa.Text()), nullable=False
+        ),
+        sa.Column(
+            "allowed_scopes", postgresql.JSONB(astext_type=sa.Text()), nullable=False
+        ),
+        sa.Column("access_token_lifetime", sa.String(length=10), nullable=False),
+        sa.Column("refresh_token_lifetime", sa.String(length=10), nullable=False),
+        sa.Column("is_active", sa.Boolean(), nullable=False),
+        sa.Column("owner_user_id", sa.UUID(), nullable=True),
+        sa.Column("mcp_server_url", sa.String(length=2048), nullable=True),
+        sa.Column("id", sa.UUID(), nullable=False),
+        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=False),
+        sa.ForeignKeyConstraint(["owner_user_id"], ["users.id"], ondelete="SET NULL"),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_index(
+        op.f("ix_oauth_clients_client_id"), "oauth_clients", ["client_id"], unique=True
+    )
+    op.create_index(
+        op.f("ix_oauth_clients_is_active"), "oauth_clients", ["is_active"], unique=False
+    )
+    op.create_table(
+        "user_organizations",
+        sa.Column("user_id", sa.UUID(), nullable=False),
+        sa.Column("organization_id", sa.UUID(), nullable=False),
+        sa.Column(
+            "role",
+            sa.Enum("OWNER", "ADMIN", "MEMBER", "GUEST", name="organizationrole"),
+            nullable=False,
+        ),
+        sa.Column("is_active", sa.Boolean(), nullable=False),
+        sa.Column("custom_permissions", sa.String(length=500), nullable=True),
+        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=False),
+        sa.ForeignKeyConstraint(
+            ["organization_id"], ["organizations.id"], ondelete="CASCADE"
+        ),
+        sa.ForeignKeyConstraint(["user_id"], ["users.id"], ondelete="CASCADE"),
+        sa.PrimaryKeyConstraint("user_id", "organization_id"),
+    )
+    op.create_index(
+        "ix_user_org_org_active",
+        "user_organizations",
+        ["organization_id", "is_active"],
+        unique=False,
+    )
+    op.create_index("ix_user_org_role", "user_organizations", ["role"], unique=False)
+    op.create_index(
+        "ix_user_org_user_active",
+        "user_organizations",
+        ["user_id", "is_active"],
+        unique=False,
+    )
+    op.create_index(
+        op.f("ix_user_organizations_is_active"),
+        "user_organizations",
+        ["is_active"],
+        unique=False,
+    )
+    op.create_table(
+        "user_sessions",
+        sa.Column("user_id", sa.UUID(), nullable=False),
+        sa.Column("refresh_token_jti", sa.String(length=255), nullable=False),
+        sa.Column("device_name", sa.String(length=255), nullable=True),
+        sa.Column("device_id", sa.String(length=255), nullable=True),
+        sa.Column("ip_address", sa.String(length=45), nullable=True),
+        sa.Column("user_agent", sa.String(length=500), nullable=True),
+        sa.Column("last_used_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("expires_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("is_active", sa.Boolean(), nullable=False),
+        sa.Column("location_city", sa.String(length=100), nullable=True),
+        sa.Column("location_country", sa.String(length=100), nullable=True),
+        sa.Column("id", sa.UUID(), nullable=False),
+        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=False),
+        sa.ForeignKeyConstraint(["user_id"], ["users.id"], ondelete="CASCADE"),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_index(
+        op.f("ix_user_sessions_is_active"), "user_sessions", ["is_active"], unique=False
+    )
+    op.create_index(
+        "ix_user_sessions_jti_active",
+        "user_sessions",
+        ["refresh_token_jti", "is_active"],
+        unique=False,
+    )
+    op.create_index(
+        op.f("ix_user_sessions_refresh_token_jti"),
+        "user_sessions",
+        ["refresh_token_jti"],
+        unique=True,
+    )
+    op.create_index(
+        "ix_user_sessions_user_active",
+        "user_sessions",
+        ["user_id", "is_active"],
+        unique=False,
+    )
+    op.create_index(
+        op.f("ix_user_sessions_user_id"), "user_sessions", ["user_id"], unique=False
+    )
+    op.create_table(
+        "oauth_authorization_codes",
+        sa.Column("code", sa.String(length=128), nullable=False),
+        sa.Column("client_id", sa.String(length=64), nullable=False),
+        sa.Column("user_id", sa.UUID(), nullable=False),
+        sa.Column("redirect_uri", sa.String(length=2048), nullable=False),
+        sa.Column("scope", sa.String(length=1000), nullable=False),
+        sa.Column("code_challenge", sa.String(length=128), nullable=True),
+        sa.Column("code_challenge_method", sa.String(length=10), nullable=True),
+        sa.Column("state", sa.String(length=256), nullable=True),
+        sa.Column("nonce", sa.String(length=256), nullable=True),
+        sa.Column("expires_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("used", sa.Boolean(), nullable=False),
+        sa.Column("id", sa.UUID(), nullable=False),
+        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=False),
+        sa.ForeignKeyConstraint(
+            ["client_id"], ["oauth_clients.client_id"], ondelete="CASCADE"
+        ),
+        sa.ForeignKeyConstraint(["user_id"], ["users.id"], ondelete="CASCADE"),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_index(
+        "ix_oauth_authorization_codes_client_user",
+        "oauth_authorization_codes",
+        ["client_id", "user_id"],
+        unique=False,
+    )
+    op.create_index(
+        op.f("ix_oauth_authorization_codes_code"),
+        "oauth_authorization_codes",
+        ["code"],
+        unique=True,
+    )
+    op.create_index(
+        "ix_oauth_authorization_codes_expires_at",
+        "oauth_authorization_codes",
+        ["expires_at"],
+        unique=False,
+    )
+    op.create_table(
+        "oauth_consents",
+        sa.Column("user_id", sa.UUID(), nullable=False),
+        sa.Column("client_id", sa.String(length=64), nullable=False),
+        sa.Column("granted_scopes", sa.String(length=1000), nullable=False),
+        sa.Column("id", sa.UUID(), nullable=False),
+        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=False),
+        sa.ForeignKeyConstraint(
+            ["client_id"], ["oauth_clients.client_id"], ondelete="CASCADE"
+        ),
+        sa.ForeignKeyConstraint(["user_id"], ["users.id"], ondelete="CASCADE"),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_index(
+        "ix_oauth_consents_user_client",
+        "oauth_consents",
+        ["user_id", "client_id"],
+        unique=True,
+    )
+    op.create_table(
+        "oauth_provider_refresh_tokens",
+        sa.Column("token_hash", sa.String(length=64), nullable=False),
+        sa.Column("jti", sa.String(length=64), nullable=False),
+        sa.Column("client_id", sa.String(length=64), nullable=False),
+        sa.Column("user_id", sa.UUID(), nullable=False),
+        sa.Column("scope", sa.String(length=1000), nullable=False),
+        sa.Column("expires_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("revoked", sa.Boolean(), nullable=False),
+        sa.Column("last_used_at", sa.DateTime(timezone=True), nullable=True),
+        sa.Column("device_info", sa.String(length=500), nullable=True),
+        sa.Column("ip_address", sa.String(length=45), nullable=True),
+        sa.Column("id", sa.UUID(), nullable=False),
+        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=False),
+        sa.ForeignKeyConstraint(
+            ["client_id"], ["oauth_clients.client_id"], ondelete="CASCADE"
+        ),
+        sa.ForeignKeyConstraint(["user_id"], ["users.id"], ondelete="CASCADE"),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_index(
+        "ix_oauth_provider_refresh_tokens_client_user",
+        "oauth_provider_refresh_tokens",
+        ["client_id", "user_id"],
+        unique=False,
+    )
+    op.create_index(
+        "ix_oauth_provider_refresh_tokens_expires_at",
+        "oauth_provider_refresh_tokens",
+        ["expires_at"],
+        unique=False,
+    )
+    op.create_index(
+        op.f("ix_oauth_provider_refresh_tokens_jti"),
+        "oauth_provider_refresh_tokens",
+        ["jti"],
+        unique=True,
+    )
+    op.create_index(
+        op.f("ix_oauth_provider_refresh_tokens_revoked"),
+        "oauth_provider_refresh_tokens",
+        ["revoked"],
+        unique=False,
+    )
+    op.create_index(
+        op.f("ix_oauth_provider_refresh_tokens_token_hash"),
+        "oauth_provider_refresh_tokens",
+        ["token_hash"],
+        unique=True,
+    )
+    op.create_index(
+        "ix_oauth_provider_refresh_tokens_user_revoked",
+        "oauth_provider_refresh_tokens",
+        ["user_id", "revoked"],
+        unique=False,
+    )
+    # ### end Alembic commands ###
+
+
+def downgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_index(
+        "ix_oauth_provider_refresh_tokens_user_revoked",
+        table_name="oauth_provider_refresh_tokens",
+    )
+    op.drop_index(
+        op.f("ix_oauth_provider_refresh_tokens_token_hash"),
+        table_name="oauth_provider_refresh_tokens",
+    )
+    op.drop_index(
+        op.f("ix_oauth_provider_refresh_tokens_revoked"),
+        table_name="oauth_provider_refresh_tokens",
+    )
+    op.drop_index(
+        op.f("ix_oauth_provider_refresh_tokens_jti"),
+        table_name="oauth_provider_refresh_tokens",
+    )
+    op.drop_index(
+        "ix_oauth_provider_refresh_tokens_expires_at",
+        table_name="oauth_provider_refresh_tokens",
+    )
+    op.drop_index(
+        "ix_oauth_provider_refresh_tokens_client_user",
+        table_name="oauth_provider_refresh_tokens",
+    )
+    op.drop_table("oauth_provider_refresh_tokens")
+    op.drop_index("ix_oauth_consents_user_client", table_name="oauth_consents")
+    op.drop_table("oauth_consents")
+    op.drop_index(
+        "ix_oauth_authorization_codes_expires_at",
+        table_name="oauth_authorization_codes",
+    )
+    op.drop_index(
+        op.f("ix_oauth_authorization_codes_code"),
+        table_name="oauth_authorization_codes",
+    )
+    op.drop_index(
+        "ix_oauth_authorization_codes_client_user",
+        table_name="oauth_authorization_codes",
+    )
+    op.drop_table("oauth_authorization_codes")
+    op.drop_index(op.f("ix_user_sessions_user_id"), table_name="user_sessions")
+    op.drop_index("ix_user_sessions_user_active", table_name="user_sessions")
+    op.drop_index(
+        op.f("ix_user_sessions_refresh_token_jti"), table_name="user_sessions"
+    )
+    op.drop_index("ix_user_sessions_jti_active", table_name="user_sessions")
+    op.drop_index(op.f("ix_user_sessions_is_active"), table_name="user_sessions")
+    op.drop_table("user_sessions")
+    op.drop_index(
+        op.f("ix_user_organizations_is_active"), table_name="user_organizations"
+    )
+    op.drop_index("ix_user_org_user_active", table_name="user_organizations")
+    op.drop_index("ix_user_org_role", table_name="user_organizations")
+    op.drop_index("ix_user_org_org_active", table_name="user_organizations")
+    op.drop_table("user_organizations")
+    op.drop_index(op.f("ix_oauth_clients_is_active"), table_name="oauth_clients")
+    op.drop_index(op.f("ix_oauth_clients_client_id"), table_name="oauth_clients")
+    op.drop_table("oauth_clients")
+    op.drop_index("ix_oauth_accounts_user_provider", table_name="oauth_accounts")
+    op.drop_index(op.f("ix_oauth_accounts_user_id"), table_name="oauth_accounts")
+    op.drop_index(op.f("ix_oauth_accounts_provider_email"), table_name="oauth_accounts")
+    op.drop_index(op.f("ix_oauth_accounts_provider"), table_name="oauth_accounts")
+    op.drop_table("oauth_accounts")
+    op.drop_index(op.f("ix_users_locale"), table_name="users")
+    op.drop_index(op.f("ix_users_is_superuser"), table_name="users")
+    op.drop_index(op.f("ix_users_is_active"), table_name="users")
+    op.drop_index(op.f("ix_users_email"), table_name="users")
+    op.drop_index(op.f("ix_users_deleted_at"), table_name="users")
+    op.drop_table("users")
+    op.drop_index("ix_organizations_slug_active", table_name="organizations")
+    op.drop_index(op.f("ix_organizations_slug"), table_name="organizations")
+    op.drop_index("ix_organizations_name_active", table_name="organizations")
+    op.drop_index(op.f("ix_organizations_name"), table_name="organizations")
+    op.drop_index(op.f("ix_organizations_is_active"), table_name="organizations")
+    op.drop_table("organizations")
+    op.drop_index(op.f("ix_oauth_states_state"), table_name="oauth_states")
+    op.drop_table("oauth_states")
+    # ### end Alembic commands ###

backend/app/alembic/versions/0002_add_performance_indexes.py

@@ -0,0 +1,127 @@
+"""Add performance indexes
+
+Revision ID: 0002
+Revises: 0001
+Create Date: 2025-11-27
+
+Performance indexes that Alembic cannot auto-detect:
+- Functional indexes (LOWER expressions)
+- Partial indexes (WHERE clauses)
+
+These indexes use the ix_perf_ prefix and are excluded from autogenerate
+via the include_object() function in env.py.
+"""
+
+from collections.abc import Sequence
+
+import sqlalchemy as sa
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision: str = "0002"
+down_revision: str | None = "0001"
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
+
+
+def upgrade() -> None:
+    # ==========================================================================
+    # USERS TABLE - Performance indexes for authentication
+    # ==========================================================================
+
+    # Case-insensitive email lookup for login/registration
+    # Query: SELECT * FROM users WHERE LOWER(email) = LOWER(:email) AND deleted_at IS NULL
+    # Impact: High - every login, registration check, password reset
+    op.create_index(
+        "ix_perf_users_email_lower",
+        "users",
+        [sa.text("LOWER(email)")],
+        unique=False,
+        postgresql_where=sa.text("deleted_at IS NULL"),
+    )
+
+    # Active users lookup (non-soft-deleted)
+    # Query: SELECT * FROM users WHERE deleted_at IS NULL AND ...
+    # Impact: Medium - user listings, admin queries
+    op.create_index(
+        "ix_perf_users_active",
+        "users",
+        ["is_active"],
+        unique=False,
+        postgresql_where=sa.text("deleted_at IS NULL"),
+    )
+
+    # ==========================================================================
+    # ORGANIZATIONS TABLE - Performance indexes for multi-tenant lookups
+    # ==========================================================================
+
+    # Case-insensitive slug lookup for URL routing
+    # Query: SELECT * FROM organizations WHERE LOWER(slug) = LOWER(:slug) AND is_active = true
+    # Impact: Medium - every organization page load
+    op.create_index(
+        "ix_perf_organizations_slug_lower",
+        "organizations",
+        [sa.text("LOWER(slug)")],
+        unique=False,
+        postgresql_where=sa.text("is_active = true"),
+    )
+
+    # ==========================================================================
+    # USER SESSIONS TABLE - Performance indexes for session management
+    # ==========================================================================
+
+    # Expired session cleanup
+    # Query: SELECT * FROM user_sessions WHERE expires_at < NOW() AND is_active = true
+    # Impact: Medium - background cleanup jobs
+    op.create_index(
+        "ix_perf_user_sessions_expires",
+        "user_sessions",
+        ["expires_at"],
+        unique=False,
+        postgresql_where=sa.text("is_active = true"),
+    )
+
+    # ==========================================================================
+    # OAUTH PROVIDER TOKENS - Performance indexes for token management
+    # ==========================================================================
+
+    # Expired refresh token cleanup
+    # Query: SELECT * FROM oauth_provider_refresh_tokens WHERE expires_at < NOW() AND revoked = false
+    # Impact: Medium - OAuth token cleanup, validation
+    op.create_index(
+        "ix_perf_oauth_refresh_tokens_expires",
+        "oauth_provider_refresh_tokens",
+        ["expires_at"],
+        unique=False,
+        postgresql_where=sa.text("revoked = false"),
+    )
+
+    # ==========================================================================
+    # OAUTH AUTHORIZATION CODES - Performance indexes for auth flow
+    # ==========================================================================
+
+    # Expired authorization code cleanup
+    # Query: DELETE FROM oauth_authorization_codes WHERE expires_at < NOW() AND used = false
+    # Impact: Low-Medium - OAuth cleanup jobs
+    op.create_index(
+        "ix_perf_oauth_auth_codes_expires",
+        "oauth_authorization_codes",
+        ["expires_at"],
+        unique=False,
+        postgresql_where=sa.text("used = false"),
+    )
+
+
+def downgrade() -> None:
+    # Drop indexes in reverse order
+    op.drop_index(
+        "ix_perf_oauth_auth_codes_expires", table_name="oauth_authorization_codes"
+    )
+    op.drop_index(
+        "ix_perf_oauth_refresh_tokens_expires",
+        table_name="oauth_provider_refresh_tokens",
+    )
+    op.drop_index("ix_perf_user_sessions_expires", table_name="user_sessions")
+    op.drop_index("ix_perf_organizations_slug_lower", table_name="organizations")
+    op.drop_index("ix_perf_users_active", table_name="users")
+    op.drop_index("ix_perf_users_email_lower", table_name="users")

backend/app/alembic/versions/0003_rename_oauth_account_token_fields_drop_encrypted_suffix.py

@@ -0,0 +1,35 @@
+"""rename oauth account token fields drop encrypted suffix
+
+Revision ID: 0003
+Revises: 0002
+Create Date: 2026-02-27 01:03:18.869178
+
+"""
+
+from collections.abc import Sequence
+
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision: str = "0003"
+down_revision: str | None = "0002"
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
+
+
+def upgrade() -> None:
+    op.alter_column(
+        "oauth_accounts", "access_token_encrypted", new_column_name="access_token"
+    )
+    op.alter_column(
+        "oauth_accounts", "refresh_token_encrypted", new_column_name="refresh_token"
+    )
+
+
+def downgrade() -> None:
+    op.alter_column(
+        "oauth_accounts", "access_token", new_column_name="access_token_encrypted"
+    )
+    op.alter_column(
+        "oauth_accounts", "refresh_token", new_column_name="refresh_token_encrypted"
+    )

backend/app/alembic/versions/1174fffbe3e4_add_performance_indexes.py

@@ -1,78 +0,0 @@
-"""add_performance_indexes
-
-Revision ID: 1174fffbe3e4
-Revises: fbf6318a8a36
-Create Date: 2025-11-01 04:15:25.367010
-
-"""
-from typing import Sequence, Union
-
-import sqlalchemy as sa
-
-from alembic import op
-
-# revision identifiers, used by Alembic.
-revision: str = '1174fffbe3e4'
-down_revision: Union[str, None] = 'fbf6318a8a36'
-branch_labels: Union[str, Sequence[str], None] = None
-depends_on: Union[str, Sequence[str], None] = None
-
-
-def upgrade() -> None:
-    """Add performance indexes for optimized queries."""
-
-    # Index for session cleanup queries
-    # Optimizes: DELETE WHERE is_active = FALSE AND expires_at < now AND created_at < cutoff
-    op.create_index(
-        'ix_user_sessions_cleanup',
-        'user_sessions',
-        ['is_active', 'expires_at', 'created_at'],
-        unique=False,
-        postgresql_where=sa.text('is_active = false')
-    )
-
-    # Index for user search queries (basic trigram support without pg_trgm extension)
-    # Optimizes: WHERE email ILIKE '%search%' OR first_name ILIKE '%search%'
-    # Note: For better performance, consider enabling pg_trgm extension
-    op.create_index(
-        'ix_users_email_lower',
-        'users',
-        [sa.text('LOWER(email)')],
-        unique=False,
-        postgresql_where=sa.text('deleted_at IS NULL')
-    )
-
-    op.create_index(
-        'ix_users_first_name_lower',
-        'users',
-        [sa.text('LOWER(first_name)')],
-        unique=False,
-        postgresql_where=sa.text('deleted_at IS NULL')
-    )
-
-    op.create_index(
-        'ix_users_last_name_lower',
-        'users',
-        [sa.text('LOWER(last_name)')],
-        unique=False,
-        postgresql_where=sa.text('deleted_at IS NULL')
-    )
-
-    # Index for organization search
-    op.create_index(
-        'ix_organizations_name_lower',
-        'organizations',
-        [sa.text('LOWER(name)')],
-        unique=False
-    )
-
-
-def downgrade() -> None:
-    """Remove performance indexes."""
-
-    # Drop indexes in reverse order
-    op.drop_index('ix_organizations_name_lower', table_name='organizations')
-    op.drop_index('ix_users_last_name_lower', table_name='users')
-    op.drop_index('ix_users_first_name_lower', table_name='users')
-    op.drop_index('ix_users_email_lower', table_name='users')
-    op.drop_index('ix_user_sessions_cleanup', table_name='user_sessions')

backend/app/alembic/versions/2d0fcec3b06d_add_soft_delete_to_users.py

@@ -1,34 +0,0 @@
-"""add_soft_delete_to_users
-
-Revision ID: 2d0fcec3b06d
-Revises: 9e4f2a1b8c7d
-Create Date: 2025-10-30 16:40:21.000021
-
-"""
-from typing import Sequence, Union
-
-import sqlalchemy as sa
-
-from alembic import op
-
-# revision identifiers, used by Alembic.
-revision: str = '2d0fcec3b06d'
-down_revision: Union[str, None] = '9e4f2a1b8c7d'
-branch_labels: Union[str, Sequence[str], None] = None
-depends_on: Union[str, Sequence[str], None] = None
-
-
-def upgrade() -> None:
-    # Add deleted_at column for soft deletes
-    op.add_column('users', sa.Column('deleted_at', sa.DateTime(timezone=True), nullable=True))
-
-    # Add index on deleted_at for efficient queries
-    op.create_index('ix_users_deleted_at', 'users', ['deleted_at'])
-
-
-def downgrade() -> None:
-    # Remove index
-    op.drop_index('ix_users_deleted_at', table_name='users')
-
-    # Remove column
-    op.drop_column('users', 'deleted_at')

backend/app/alembic/versions/38bf9e7e74b3_add_all_initial_models.py

@@ -1,46 +0,0 @@
-"""Add all initial models
-
-Revision ID: 38bf9e7e74b3
-Revises: 7396957cbe80
-Create Date: 2025-02-28 09:19:33.212278
-
-"""
-from typing import Sequence, Union
-
-import sqlalchemy as sa
-
-from alembic import op
-
-# revision identifiers, used by Alembic.
-revision: str = '38bf9e7e74b3'
-down_revision: Union[str, None] = '7396957cbe80'
-branch_labels: Union[str, Sequence[str], None] = None
-depends_on: Union[str, Sequence[str], None] = None
-
-
-def upgrade() -> None:
-
-    op.create_table('users',
-    sa.Column('email', sa.String(), nullable=False),
-    sa.Column('password_hash', sa.String(), nullable=False),
-    sa.Column('first_name', sa.String(), nullable=False),
-    sa.Column('last_name', sa.String(), nullable=True),
-    sa.Column('phone_number', sa.String(), nullable=True),
-    sa.Column('is_active', sa.Boolean(), nullable=False),
-    sa.Column('is_superuser', sa.Boolean(), nullable=False),
-    sa.Column('preferences', sa.JSON(), nullable=True),
-    sa.Column('id', sa.UUID(), nullable=False),
-    sa.Column('created_at', sa.DateTime(timezone=True), nullable=False),
-    sa.Column('updated_at', sa.DateTime(timezone=True), nullable=False),
-    sa.PrimaryKeyConstraint('id')
-    )
-    op.create_index(op.f('ix_users_email'), 'users', ['email'], unique=True)
-
-    # ### end Alembic commands ###
-
-
-def downgrade() -> None:
-    # ### commands auto generated by Alembic - please adjust! ###
-    op.drop_index(op.f('ix_users_email'), table_name='users')
-    op.drop_table('users')
-    # ### end Alembic commands ###

backend/app/alembic/versions/549b50ea888d_add_user_sessions_table.py

@@ -1,102 +0,0 @@
-"""add_user_sessions_table
-
-Revision ID: 549b50ea888d
-Revises: b76c725fc3cf
-Create Date: 2025-10-31 07:41:18.729544
-
-"""
-from typing import Sequence, Union
-
-import sqlalchemy as sa
-
-from alembic import op
-
-# revision identifiers, used by Alembic.
-revision: str = '549b50ea888d'
-down_revision: Union[str, None] = 'b76c725fc3cf'
-branch_labels: Union[str, Sequence[str], None] = None
-depends_on: Union[str, Sequence[str], None] = None
-
-
-def upgrade() -> None:
-    # Create user_sessions table for per-device session management
-    op.create_table(
-        'user_sessions',
-        sa.Column('id', sa.UUID(), nullable=False),
-        sa.Column('user_id', sa.UUID(), nullable=False),
-        sa.Column('refresh_token_jti', sa.String(length=255), nullable=False),
-        sa.Column('device_name', sa.String(length=255), nullable=True),
-        sa.Column('device_id', sa.String(length=255), nullable=True),
-        sa.Column('ip_address', sa.String(length=45), nullable=True),
-        sa.Column('user_agent', sa.String(length=500), nullable=True),
-        sa.Column('last_used_at', sa.DateTime(timezone=True), nullable=False),
-        sa.Column('expires_at', sa.DateTime(timezone=True), nullable=False),
-        sa.Column('is_active', sa.Boolean(), nullable=False, server_default='true'),
-        sa.Column('location_city', sa.String(length=100), nullable=True),
-        sa.Column('location_country', sa.String(length=100), nullable=True),
-        sa.Column('created_at', sa.DateTime(timezone=True), nullable=False),
-        sa.Column('updated_at', sa.DateTime(timezone=True), nullable=False),
-        sa.PrimaryKeyConstraint('id')
-    )
-
-    # Create foreign key to users table
-    op.create_foreign_key(
-        'fk_user_sessions_user_id',
-        'user_sessions',
-        'users',
-        ['user_id'],
-        ['id'],
-        ondelete='CASCADE'
-    )
-
-    # Create indexes for performance
-    # 1. Lookup session by refresh token JTI (most common query)
-    op.create_index(
-        'ix_user_sessions_jti',
-        'user_sessions',
-        ['refresh_token_jti'],
-        unique=True
-    )
-
-    # 2. Lookup sessions by user ID
-    op.create_index(
-        'ix_user_sessions_user_id',
-        'user_sessions',
-        ['user_id']
-    )
-
-    # 3. Composite index for active sessions by user
-    op.create_index(
-        'ix_user_sessions_user_active',
-        'user_sessions',
-        ['user_id', 'is_active']
-    )
-
-    # 4. Index on expires_at for cleanup job
-    op.create_index(
-        'ix_user_sessions_expires_at',
-        'user_sessions',
-        ['expires_at']
-    )
-
-    # 5. Composite index for active session lookup by JTI
-    op.create_index(
-        'ix_user_sessions_jti_active',
-        'user_sessions',
-        ['refresh_token_jti', 'is_active']
-    )
-
-
-def downgrade() -> None:
-    # Drop indexes first
-    op.drop_index('ix_user_sessions_jti_active', table_name='user_sessions')
-    op.drop_index('ix_user_sessions_expires_at', table_name='user_sessions')
-    op.drop_index('ix_user_sessions_user_active', table_name='user_sessions')
-    op.drop_index('ix_user_sessions_user_id', table_name='user_sessions')
-    op.drop_index('ix_user_sessions_jti', table_name='user_sessions')
-
-    # Drop foreign key
-    op.drop_constraint('fk_user_sessions_user_id', 'user_sessions', type_='foreignkey')
-
-    # Drop table
-    op.drop_table('user_sessions')

backend/app/alembic/versions/7396957cbe80_initial_empty_migration.py

@@ -1,24 +0,0 @@
-"""Initial empty migration
-
-Revision ID: 7396957cbe80
-Revises: 
-Create Date: 2025-02-27 12:47:46.445313
-
-"""
-from typing import Sequence, Union
-
-from alembic import op
-
-# revision identifiers, used by Alembic.
-revision: str = '7396957cbe80'
-down_revision: Union[str, None] = None
-branch_labels: Union[str, Sequence[str], None] = None
-depends_on: Union[str, Sequence[str], None] = None
-
-
-def upgrade() -> None:
-    pass
-
-
-def downgrade() -> None:
-    pass

backend/app/alembic/versions/9e4f2a1b8c7d_add_missing_indexes_and_fix_column_types.py

@@ -1,84 +0,0 @@
-"""Add missing indexes and fix column types
-
-Revision ID: 9e4f2a1b8c7d
-Revises: 38bf9e7e74b3
-Create Date: 2025-10-30 10:00:00.000000
-
-"""
-from typing import Sequence, Union
-
-import sqlalchemy as sa
-
-from alembic import op
-
-# revision identifiers, used by Alembic.
-revision: str = '9e4f2a1b8c7d'
-down_revision: Union[str, None] = '38bf9e7e74b3'
-branch_labels: Union[str, Sequence[str], None] = None
-depends_on: Union[str, Sequence[str], None] = None
-
-
-def upgrade() -> None:
-    # Add missing indexes for is_active and is_superuser
-    op.create_index(op.f('ix_users_is_active'), 'users', ['is_active'], unique=False)
-    op.create_index(op.f('ix_users_is_superuser'), 'users', ['is_superuser'], unique=False)
-
-    # Fix column types to match model definitions with explicit lengths
-    op.alter_column('users', 'email',
-               existing_type=sa.String(),
-               type_=sa.String(length=255),
-               nullable=False)
-
-    op.alter_column('users', 'password_hash',
-               existing_type=sa.String(),
-               type_=sa.String(length=255),
-               nullable=False)
-
-    op.alter_column('users', 'first_name',
-               existing_type=sa.String(),
-               type_=sa.String(length=100),
-               nullable=False,
-               server_default='user')  # Add server default
-
-    op.alter_column('users', 'last_name',
-               existing_type=sa.String(),
-               type_=sa.String(length=100),
-               nullable=True)
-
-    op.alter_column('users', 'phone_number',
-               existing_type=sa.String(),
-               type_=sa.String(length=20),
-               nullable=True)
-
-
-def downgrade() -> None:
-    # Revert column types
-    op.alter_column('users', 'phone_number',
-               existing_type=sa.String(length=20),
-               type_=sa.String(),
-               nullable=True)
-
-    op.alter_column('users', 'last_name',
-               existing_type=sa.String(length=100),
-               type_=sa.String(),
-               nullable=True)
-
-    op.alter_column('users', 'first_name',
-               existing_type=sa.String(length=100),
-               type_=sa.String(),
-               nullable=False,
-               server_default=None)  # Remove server default
-
-    op.alter_column('users', 'password_hash',
-               existing_type=sa.String(length=255),
-               type_=sa.String(),
-               nullable=False)
-
-    op.alter_column('users', 'email',
-               existing_type=sa.String(length=255),
-               type_=sa.String(),
-               nullable=False)
-
-    # Drop indexes
-    op.drop_index(op.f('ix_users_is_superuser'), table_name='users')
-    op.drop_index(op.f('ix_users_is_active'), table_name='users')

backend/app/alembic/versions/b76c725fc3cf_add_composite_indexes.py

@@ -1,52 +0,0 @@
-"""add_composite_indexes
-
-Revision ID: b76c725fc3cf
-Revises: 2d0fcec3b06d
-Create Date: 2025-10-30 16:41:33.273135
-
-"""
-from typing import Sequence, Union
-
-import sqlalchemy as sa
-
-from alembic import op
-
-# revision identifiers, used by Alembic.
-revision: str = 'b76c725fc3cf'
-down_revision: Union[str, None] = '2d0fcec3b06d'
-branch_labels: Union[str, Sequence[str], None] = None
-depends_on: Union[str, Sequence[str], None] = None
-
-
-def upgrade() -> None:
-    # Add composite indexes for common query patterns
-
-    # Composite index for filtering active users by role
-    op.create_index(
-        'ix_users_active_superuser',
-        'users',
-        ['is_active', 'is_superuser'],
-        postgresql_where=sa.text('deleted_at IS NULL')
-    )
-
-    # Composite index for sorting active users by creation date
-    op.create_index(
-        'ix_users_active_created',
-        'users',
-        ['is_active', 'created_at'],
-        postgresql_where=sa.text('deleted_at IS NULL')
-    )
-
-    # Composite index for email lookup of non-deleted users
-    op.create_index(
-        'ix_users_email_not_deleted',
-        'users',
-        ['email', 'deleted_at']
-    )
-
-
-def downgrade() -> None:
-    # Remove composite indexes
-    op.drop_index('ix_users_email_not_deleted', table_name='users')
-    op.drop_index('ix_users_active_created', table_name='users')
-    op.drop_index('ix_users_active_superuser', table_name='users')

backend/app/alembic/versions/fbf6318a8a36_add_organizations_and_user_organizations.py

@@ -1,106 +0,0 @@
-"""add_organizations_and_user_organizations
-
-Revision ID: fbf6318a8a36
-Revises: 549b50ea888d
-Create Date: 2025-10-31 12:08:05.141353
-
-"""
-from typing import Sequence, Union
-
-import sqlalchemy as sa
-
-from alembic import op
-
-# revision identifiers, used by Alembic.
-revision: str = 'fbf6318a8a36'
-down_revision: Union[str, None] = '549b50ea888d'
-branch_labels: Union[str, Sequence[str], None] = None
-depends_on: Union[str, Sequence[str], None] = None
-
-
-def upgrade() -> None:
-    # Create organizations table
-    op.create_table(
-        'organizations',
-        sa.Column('id', sa.UUID(), nullable=False),
-        sa.Column('name', sa.String(length=255), nullable=False),
-        sa.Column('slug', sa.String(length=255), nullable=False),
-        sa.Column('description', sa.Text(), nullable=True),
-        sa.Column('is_active', sa.Boolean(), nullable=False, server_default='true'),
-        sa.Column('settings', sa.JSON(), nullable=True),
-        sa.Column('created_at', sa.DateTime(timezone=True), nullable=False),
-        sa.Column('updated_at', sa.DateTime(timezone=True), nullable=False),
-        sa.PrimaryKeyConstraint('id')
-    )
-
-    # Create indexes for organizations
-    op.create_index('ix_organizations_name', 'organizations', ['name'])
-    op.create_index('ix_organizations_slug', 'organizations', ['slug'], unique=True)
-    op.create_index('ix_organizations_is_active', 'organizations', ['is_active'])
-    op.create_index('ix_organizations_name_active', 'organizations', ['name', 'is_active'])
-    op.create_index('ix_organizations_slug_active', 'organizations', ['slug', 'is_active'])
-
-    # Create user_organizations junction table
-    op.create_table(
-        'user_organizations',
-        sa.Column('user_id', sa.UUID(), nullable=False),
-        sa.Column('organization_id', sa.UUID(), nullable=False),
-        sa.Column('role', sa.Enum('OWNER', 'ADMIN', 'MEMBER', 'GUEST', name='organizationrole'), nullable=False, server_default='MEMBER'),
-        sa.Column('is_active', sa.Boolean(), nullable=False, server_default='true'),
-        sa.Column('custom_permissions', sa.String(length=500), nullable=True),
-        sa.Column('created_at', sa.DateTime(timezone=True), nullable=False),
-        sa.Column('updated_at', sa.DateTime(timezone=True), nullable=False),
-        sa.PrimaryKeyConstraint('user_id', 'organization_id')
-    )
-
-    # Create foreign keys
-    op.create_foreign_key(
-        'fk_user_organizations_user_id',
-        'user_organizations',
-        'users',
-        ['user_id'],
-        ['id'],
-        ondelete='CASCADE'
-    )
-    op.create_foreign_key(
-        'fk_user_organizations_organization_id',
-        'user_organizations',
-        'organizations',
-        ['organization_id'],
-        ['id'],
-        ondelete='CASCADE'
-    )
-
-    # Create indexes for user_organizations
-    op.create_index('ix_user_organizations_role', 'user_organizations', ['role'])
-    op.create_index('ix_user_organizations_is_active', 'user_organizations', ['is_active'])
-    op.create_index('ix_user_org_user_active', 'user_organizations', ['user_id', 'is_active'])
-    op.create_index('ix_user_org_org_active', 'user_organizations', ['organization_id', 'is_active'])
-
-
-def downgrade() -> None:
-    # Drop indexes for user_organizations
-    op.drop_index('ix_user_org_org_active', table_name='user_organizations')
-    op.drop_index('ix_user_org_user_active', table_name='user_organizations')
-    op.drop_index('ix_user_organizations_is_active', table_name='user_organizations')
-    op.drop_index('ix_user_organizations_role', table_name='user_organizations')
-
-    # Drop foreign keys
-    op.drop_constraint('fk_user_organizations_organization_id', 'user_organizations', type_='foreignkey')
-    op.drop_constraint('fk_user_organizations_user_id', 'user_organizations', type_='foreignkey')
-
-    # Drop user_organizations table
-    op.drop_table('user_organizations')
-
-    # Drop indexes for organizations
-    op.drop_index('ix_organizations_slug_active', table_name='organizations')
-    op.drop_index('ix_organizations_name_active', table_name='organizations')
-    op.drop_index('ix_organizations_is_active', table_name='organizations')
-    op.drop_index('ix_organizations_slug', table_name='organizations')
-    op.drop_index('ix_organizations_name', table_name='organizations')
-
-    # Drop organizations table
-    op.drop_table('organizations')
-
-    # Drop enum type
-    op.execute('DROP TYPE IF EXISTS organizationrole')

backend/app/api/dependencies/auth.py

@@ -1,22 +1,19 @@
-from typing import Optional
-
-from fastapi import Depends, HTTPException, status, Header
+from fastapi import Depends, Header, HTTPException, status
 from fastapi.security import OAuth2PasswordBearer
 from fastapi.security.utils import get_authorization_scheme_param
-from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
-from app.core.auth import get_token_data, TokenExpiredError, TokenInvalidError
+from app.core.auth import TokenExpiredError, TokenInvalidError, get_token_data
 from app.core.database import get_db
 from app.models.user import User
+from app.repositories.user import user_repo
 
 # OAuth2 configuration
 oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/api/v1/auth/login")
 
 
 async def get_current_user(
-        db: AsyncSession = Depends(get_db),
-        token: str = Depends(oauth2_scheme)
+    db: AsyncSession = Depends(get_db), token: str = Depends(oauth2_scheme)
 ) -> User:
     """
     Get the current authenticated user.
@@ -35,22 +32,17 @@ async def get_current_user(
         # Decode token and get user ID
         token_data = get_token_data(token)
 
-        # Get user from database
-        result = await db.execute(
-            select(User).where(User.id == token_data.user_id)
-        )
-        user = result.scalar_one_or_none()
+        # Get user from database via repository
+        user = await user_repo.get(db, id=str(token_data.user_id))
 
         if not user:
             raise HTTPException(
-                status_code=status.HTTP_404_NOT_FOUND,
-                detail="User not found"
+                status_code=status.HTTP_404_NOT_FOUND, detail="User not found"
             )
 
         if not user.is_active:
             raise HTTPException(
-                status_code=status.HTTP_403_FORBIDDEN,
-                detail="Inactive user"
+                status_code=status.HTTP_403_FORBIDDEN, detail="Inactive user"
             )
 
         return user
@@ -59,19 +51,17 @@ async def get_current_user(
         raise HTTPException(
             status_code=status.HTTP_401_UNAUTHORIZED,
             detail="Token expired",
-            headers={"WWW-Authenticate": "Bearer"}
+            headers={"WWW-Authenticate": "Bearer"},
         )
     except TokenInvalidError:
         raise HTTPException(
             status_code=status.HTTP_401_UNAUTHORIZED,
             detail="Could not validate credentials",
-            headers={"WWW-Authenticate": "Bearer"}
+            headers={"WWW-Authenticate": "Bearer"},
         )
 
 
-def get_current_active_user(
-        current_user: User = Depends(get_current_user)
-) -> User:
+def get_current_active_user(current_user: User = Depends(get_current_user)) -> User:
     """
     Check if the current user is active.
 
@@ -86,15 +76,12 @@ def get_current_active_user(
     """
     if not current_user.is_active:
         raise HTTPException(
-            status_code=status.HTTP_403_FORBIDDEN,
-            detail="Inactive user"
+            status_code=status.HTTP_403_FORBIDDEN, detail="Inactive user"
         )
     return current_user
 
 
-def get_current_superuser(
-        current_user: User = Depends(get_current_user)
-) -> User:
+def get_current_superuser(current_user: User = Depends(get_current_user)) -> User:
     """
     Check if the current user is a superuser.
 
@@ -109,13 +96,12 @@ def get_current_superuser(
     """
     if not current_user.is_superuser:
         raise HTTPException(
-            status_code=status.HTTP_403_FORBIDDEN,
-            detail="Not enough permissions"
+            status_code=status.HTTP_403_FORBIDDEN, detail="Not enough permissions"
         )
     return current_user
 
 
-async def get_optional_token(authorization: str = Header(None)) -> Optional[str]:
+async def get_optional_token(authorization: str = Header(None)) -> str | None:
     """
     Get the token from the Authorization header without requiring it.
 
@@ -139,9 +125,8 @@ async def get_optional_token(authorization: str = Header(None)) -> Optional[str]
 
 
 async def get_optional_current_user(
-        db: AsyncSession = Depends(get_db),
-        token: Optional[str] = Depends(get_optional_token)
-) -> Optional[User]:
+    db: AsyncSession = Depends(get_db), token: str | None = Depends(get_optional_token)
+) -> User | None:
     """
     Get the current user if authenticated, otherwise return None.
     Useful for endpoints that work with both authenticated and unauthenticated users.
@@ -158,12 +143,9 @@ async def get_optional_current_user(
 
     try:
         token_data = get_token_data(token)
-        result = await db.execute(
-            select(User).where(User.id == token_data.user_id)
-        )
-        user = result.scalar_one_or_none()
+        user = await user_repo.get(db, id=str(token_data.user_id))
         if not user or not user.is_active:
             return None
         return user
     except (TokenExpiredError, TokenInvalidError):
-        return None
+        return None

backend/app/api/dependencies/locale.py

@@ -0,0 +1,132 @@
+# app/api/dependencies/locale.py
+"""
+Locale detection dependency for internationalization (i18n).
+
+Implements a three-tier fallback system:
+1. User's saved preference (if authenticated and user.locale is set)
+2. Accept-Language header (for unauthenticated users or no saved preference)
+3. Default to English ("en")
+"""
+
+from fastapi import Depends, Request
+
+from app.api.dependencies.auth import get_optional_current_user
+from app.models.user import User
+
+# Supported locales (BCP 47 format)
+# Template showcases English and Italian
+# Users can extend by adding more locales here
+# Note: Stored in lowercase for case-insensitive matching
+SUPPORTED_LOCALES = {"en", "it", "en-us", "en-gb", "it-it"}
+DEFAULT_LOCALE = "en"
+
+
+def parse_accept_language(accept_language: str) -> str | None:
+    """
+    Parse the Accept-Language header and return the best matching supported locale.
+
+    The Accept-Language header format is:
+    "it-IT,it;q=0.9,en-US;q=0.8,en;q=0.7"
+
+    This function extracts locales in priority order (by quality value) and returns
+    the first one that matches our supported locales.
+
+    Args:
+        accept_language: The Accept-Language header value
+
+    Returns:
+        The best matching locale code, or None if no match found
+
+    Examples:
+        >>> parse_accept_language("it-IT,it;q=0.9,en;q=0.8")
+        "it-IT"  # or "it" if it-IT is not supported
+        >>> parse_accept_language("fr-FR,fr;q=0.9")
+        None  # French not supported
+    """
+    if not accept_language:
+        return None
+
+    # Split by comma to get individual locale entries
+    # Format: "locale;q=weight" or just "locale"
+    locales = []
+    for entry in accept_language.split(","):
+        # Remove quality value (;q=0.9) if present
+        locale = entry.split(";")[0].strip()
+        if locale:
+            locales.append(locale)
+
+    # Check each locale in priority order
+    for locale in locales:
+        locale_lower = locale.lower()
+
+        # Try exact match first (e.g., "it-IT")
+        if locale_lower in SUPPORTED_LOCALES:
+            return locale_lower
+
+        # Try language code only (e.g., "it" from "it-IT")
+        lang_code = locale_lower.split("-")[0]
+        if lang_code in SUPPORTED_LOCALES:
+            return lang_code
+
+    return None
+
+
+async def get_locale(
+    request: Request,
+    current_user: User | None = Depends(get_optional_current_user),
+) -> str:
+    """
+    Detect and return the appropriate locale for the current request.
+
+    Three-tier fallback system:
+    1. **User Preference** (highest priority)
+       - If user is authenticated and has a saved locale preference, use it
+       - This persists across sessions and devices
+
+    2. **Accept-Language Header** (second priority)
+       - Parse the Accept-Language header from the request
+       - Match against supported locales
+       - Common for browser requests
+
+    3. **Default Locale** (fallback)
+       - Return "en" (English) if no user preference and no header match
+
+    Args:
+        request: The FastAPI request object (for accessing headers)
+        current_user: The current authenticated user (optional)
+
+    Returns:
+        A valid locale code from SUPPORTED_LOCALES (guaranteed to be supported)
+
+    Examples:
+        >>> # Authenticated user with saved preference
+        >>> await get_locale(request, user_with_locale_it)
+        "it"
+
+        >>> # Unauthenticated user with Italian browser
+        >>> # (request has Accept-Language: it-IT,it;q=0.9)
+        >>> await get_locale(request, None)
+        "it"
+
+        >>> # Unauthenticated user with unsupported language
+        >>> # (request has Accept-Language: fr-FR,fr;q=0.9)
+        >>> await get_locale(request, None)
+        "en"
+    """
+    # Priority 1: User's saved preference
+    if current_user and current_user.locale:
+        # Validate that saved locale is still supported
+        # (in case SUPPORTED_LOCALES changed after user set preference)
+        locale_value = str(current_user.locale)
+        if locale_value in SUPPORTED_LOCALES:
+            return locale_value
+
+    # Priority 2: Accept-Language header
+    accept_language = request.headers.get("accept-language", "")
+    if accept_language:
+        detected_locale = parse_accept_language(accept_language)
+        if detected_locale:
+            return detected_locale
+
+    # Priority 3: Default fallback
+    return DEFAULT_LOCALE

backend/app/api/dependencies/permissions.py

@@ -7,7 +7,7 @@ These dependencies are optional and flexible:
 - Use require_org_role for organization-specific access control
 - Projects can choose to use these or implement their own permission system
 """
-from typing import Optional
+
 from uuid import UUID
 
 from fastapi import Depends, HTTPException, status
@@ -15,14 +15,12 @@ from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.api.dependencies.auth import get_current_user
 from app.core.database import get_db
-from app.crud.organization import organization as organization_crud
 from app.models.user import User
 from app.models.user_organization import OrganizationRole
+from app.services.organization_service import organization_service
 
 
-def require_superuser(
-    current_user: User = Depends(get_current_user)
-) -> User:
+def require_superuser(current_user: User = Depends(get_current_user)) -> User:
     """
     Dependency to ensure the current user is a superuser.
 
@@ -36,7 +34,7 @@ def require_superuser(
     if not current_user.is_superuser:
         raise HTTPException(
             status_code=status.HTTP_403_FORBIDDEN,
-            detail="Superuser privileges required"
+            detail="Superuser privileges required",
         )
     return current_user
 
@@ -62,7 +60,7 @@ class OrganizationPermission:
         self,
         organization_id: UUID,
         current_user: User = Depends(get_current_user),
-        db: AsyncSession = Depends(get_db)
+        db: AsyncSession = Depends(get_db),
     ) -> User:
         """
         Check if user has required role in the organization.
@@ -83,22 +81,20 @@ class OrganizationPermission:
             return current_user
 
         # Get user's role in organization
-        user_role = await organization_crud.get_user_role_in_org(
-            db,
-            user_id=current_user.id,
-            organization_id=organization_id
+        user_role = await organization_service.get_user_role_in_org(
+            db, user_id=current_user.id, organization_id=organization_id
         )
 
         if not user_role:
             raise HTTPException(
                 status_code=status.HTTP_403_FORBIDDEN,
-                detail="Not a member of this organization"
+                detail="Not a member of this organization",
             )
 
         if user_role not in self.allowed_roles:
             raise HTTPException(
                 status_code=status.HTTP_403_FORBIDDEN,
-                detail=f"Role {user_role} not authorized. Required: {self.allowed_roles}"
+                detail=f"Role {user_role} not authorized. Required: {self.allowed_roles}",
             )
 
         return current_user
@@ -106,18 +102,18 @@ class OrganizationPermission:
 
 # Common permission presets for convenience
 require_org_owner = OrganizationPermission([OrganizationRole.OWNER])
-require_org_admin = OrganizationPermission([OrganizationRole.OWNER, OrganizationRole.ADMIN])
-require_org_member = OrganizationPermission([
-    OrganizationRole.OWNER,
-    OrganizationRole.ADMIN,
-    OrganizationRole.MEMBER
-])
+require_org_admin = OrganizationPermission(
+    [OrganizationRole.OWNER, OrganizationRole.ADMIN]
+)
+require_org_member = OrganizationPermission(
+    [OrganizationRole.OWNER, OrganizationRole.ADMIN, OrganizationRole.MEMBER]
+)
 
 
 async def require_org_membership(
     organization_id: UUID,
     current_user: User = Depends(get_current_user),
-    db: AsyncSession = Depends(get_db)
+    db: AsyncSession = Depends(get_db),
 ) -> User:
     """
     Ensure user is a member of the organization (any role).
@@ -127,16 +123,14 @@ async def require_org_membership(
     if current_user.is_superuser:
         return current_user
 
-    user_role = await organization_crud.get_user_role_in_org(
-        db,
-        user_id=current_user.id,
-        organization_id=organization_id
+    user_role = await organization_service.get_user_role_in_org(
+        db, user_id=current_user.id, organization_id=organization_id
     )
 
     if not user_role:
         raise HTTPException(
             status_code=status.HTTP_403_FORBIDDEN,
-            detail="Not a member of this organization"
+            detail="Not a member of this organization",
         )
 
     return current_user

backend/app/api/dependencies/services.py

@@ -0,0 +1,41 @@
+# app/api/dependencies/services.py
+"""FastAPI dependency functions for service singletons."""
+
+from app.services import oauth_provider_service
+from app.services.auth_service import AuthService
+from app.services.oauth_service import OAuthService
+from app.services.organization_service import OrganizationService, organization_service
+from app.services.session_service import SessionService, session_service
+from app.services.user_service import UserService, user_service
+
+
+def get_auth_service() -> AuthService:
+    """Return the AuthService singleton for dependency injection."""
+    from app.services.auth_service import AuthService as _AuthService
+
+    return _AuthService()
+
+
+def get_user_service() -> UserService:
+    """Return the UserService singleton for dependency injection."""
+    return user_service
+
+
+def get_organization_service() -> OrganizationService:
+    """Return the OrganizationService singleton for dependency injection."""
+    return organization_service
+
+
+def get_session_service() -> SessionService:
+    """Return the SessionService singleton for dependency injection."""
+    return session_service
+
+
+def get_oauth_service() -> OAuthService:
+    """Return OAuthService for dependency injection."""
+    return OAuthService()
+
+
+def get_oauth_provider_service():
+    """Return the oauth_provider_service module for dependency injection."""
+    return oauth_provider_service

backend/app/api/main.py

@@ -1,10 +1,24 @@
 from fastapi import APIRouter
 
-from app.api.routes import auth, users, sessions, admin, organizations
+from app.api.routes import (
+    admin,
+    auth,
+    oauth,
+    oauth_provider,
+    organizations,
+    sessions,
+    users,
+)
 
 api_router = APIRouter()
 api_router.include_router(auth.router, prefix="/auth", tags=["Authentication"])
+api_router.include_router(oauth.router, prefix="/oauth", tags=["OAuth"])
+api_router.include_router(
+    oauth_provider.router, prefix="/oauth", tags=["OAuth Provider"]
+)
 api_router.include_router(users.router, prefix="/users", tags=["Users"])
 api_router.include_router(sessions.router, prefix="/sessions", tags=["Sessions"])
 api_router.include_router(admin.router, prefix="/admin", tags=["Admin"])
-api_router.include_router(organizations.router, prefix="/organizations", tags=["Organizations"])
+api_router.include_router(
+    organizations.router, prefix="/organizations", tags=["Organizations"]
+)

backend/app/api/routes/auth.py

@@ -1,40 +1,44 @@
 # app/api/routes/auth.py
 import logging
 import os
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 from typing import Any
 
-from fastapi import APIRouter, Depends, HTTPException, status, Request
+from fastapi import APIRouter, Depends, HTTPException, Request, status
 from fastapi.security import OAuth2PasswordRequestForm
 from slowapi import Limiter
 from slowapi.util import get_remote_address
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.api.dependencies.auth import get_current_user
-from app.core.auth import TokenExpiredError, TokenInvalidError, decode_token
-from app.core.auth import get_password_hash
+from app.core.auth import (
+    TokenExpiredError,
+    TokenInvalidError,
+    decode_token,
+)
 from app.core.database import get_db
 from app.core.exceptions import (
     AuthenticationError as AuthError,
     DatabaseError,
-    ErrorCode
+    DuplicateError,
+    ErrorCode,
 )
-from app.crud.session import session as session_crud
-from app.crud.user import user as user_crud
 from app.models.user import User
 from app.schemas.common import MessageResponse
-from app.schemas.sessions import SessionCreate, LogoutRequest
+from app.schemas.sessions import LogoutRequest, SessionCreate
 from app.schemas.users import (
+    LoginRequest,
+    PasswordResetConfirm,
+    PasswordResetRequest,
+    RefreshTokenRequest,
+    Token,
     UserCreate,
     UserResponse,
-    Token,
-    LoginRequest,
-    RefreshTokenRequest,
-    PasswordResetRequest,
-    PasswordResetConfirm
 )
-from app.services.auth_service import AuthService, AuthenticationError
+from app.services.auth_service import AuthenticationError, AuthService
 from app.services.email_service import email_service
+from app.services.session_service import session_service
+from app.services.user_service import user_service
 from app.utils.device import extract_device_info
 from app.utils.security import create_password_reset_token, verify_password_reset_token
 
@@ -54,7 +58,7 @@ async def _create_login_session(
     request: Request,
     user: User,
     tokens: Token,
-    login_type: str = "login"
+    login_type: str = "login",
 ) -> None:
     """
     Create a session record for successful login.
@@ -81,29 +85,35 @@ async def _create_login_session(
             device_id=device_info.device_id,
             ip_address=device_info.ip_address,
             user_agent=device_info.user_agent,
-            last_used_at=datetime.now(timezone.utc),
-            expires_at=datetime.fromtimestamp(refresh_payload.exp, tz=timezone.utc),
+            last_used_at=datetime.now(UTC),
+            expires_at=datetime.fromtimestamp(refresh_payload.exp, tz=UTC),
             location_city=device_info.location_city,
             location_country=device_info.location_country,
         )
 
-        await session_crud.create_session(db, obj_in=session_data)
+        await session_service.create_session(db, obj_in=session_data)
 
         logger.info(
-            f"{login_type.capitalize()} successful: {user.email} from {device_info.device_name} "
-            f"(IP: {device_info.ip_address})"
+            "%s successful: %s from %s (IP: %s)",
+            login_type.capitalize(),
+            user.email,
+            device_info.device_name,
+            device_info.ip_address,
         )
     except Exception as session_err:
         # Log but don't fail login if session creation fails
-        logger.error(f"Failed to create session for {user.email}: {str(session_err)}", exc_info=True)
+        logger.exception("Failed to create session for %s: %s", user.email, session_err)
 
 
-@router.post("/register", response_model=UserResponse, status_code=status.HTTP_201_CREATED, operation_id="register")
+@router.post(
+    "/register",
+    response_model=UserResponse,
+    status_code=status.HTTP_201_CREATED,
+    operation_id="register",
+)
 @limiter.limit(f"{5 * RATE_MULTIPLIER}/minute")
 async def register_user(
-        request: Request,
-        user_data: UserCreate,
-        db: AsyncSession = Depends(get_db)
+    request: Request, user_data: UserCreate, db: AsyncSession = Depends(get_db)
 ) -> Any:
     """
     Register a new user.
@@ -114,27 +124,31 @@ async def register_user(
     try:
         user = await AuthService.create_user(db, user_data)
         return user
-    except AuthenticationError as e:
+    except DuplicateError:
         # SECURITY: Don't reveal if email exists - generic error message
-        logger.warning(f"Registration failed: {str(e)}")
+        logger.warning("Registration failed: duplicate email %s", user_data.email)
         raise HTTPException(
             status_code=status.HTTP_400_BAD_REQUEST,
-            detail="Registration failed. Please check your information and try again."
+            detail="Registration failed. Please check your information and try again.",
+        )
+    except AuthError as e:
+        logger.warning("Registration failed: %s", e)
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Registration failed. Please check your information and try again.",
         )
     except Exception as e:
-        logger.error(f"Unexpected error during registration: {str(e)}", exc_info=True)
+        logger.exception("Unexpected error during registration: %s", e)
         raise DatabaseError(
             message="An unexpected error occurred. Please try again later.",
-            error_code=ErrorCode.INTERNAL_ERROR
+            error_code=ErrorCode.INTERNAL_ERROR,
         )
 
 
 @router.post("/login", response_model=Token, operation_id="login")
 @limiter.limit(f"{10 * RATE_MULTIPLIER}/minute")
 async def login(
-        request: Request,
-        login_data: LoginRequest,
-        db: AsyncSession = Depends(get_db)
+    request: Request, login_data: LoginRequest, db: AsyncSession = Depends(get_db)
 ) -> Any:
     """
     Login with username and password.
@@ -146,14 +160,16 @@ async def login(
     """
     try:
         # Attempt to authenticate the user
-        user = await AuthService.authenticate_user(db, login_data.email, login_data.password)
+        user = await AuthService.authenticate_user(
+            db, login_data.email, login_data.password
+        )
 
         # Explicitly check for None result and raise correct exception
         if user is None:
-            logger.warning(f"Invalid login attempt for: {login_data.email}")
+            logger.warning("Invalid login attempt for: %s", login_data.email)
             raise AuthError(
                 message="Invalid email or password",
-                error_code=ErrorCode.INVALID_CREDENTIALS
+                error_code=ErrorCode.INVALID_CREDENTIALS,
             )
 
         # User is authenticated, generate tokens
@@ -166,29 +182,23 @@ async def login(
 
     except AuthenticationError as e:
         # Handle specific authentication errors like inactive accounts
-        logger.warning(f"Authentication failed: {str(e)}")
-        raise AuthError(
-            message=str(e),
-            error_code=ErrorCode.INVALID_CREDENTIALS
-        )
-    except AuthError:
-        # Re-raise custom auth exceptions without modification
-        raise
+        logger.warning("Authentication failed: %s", e)
+        raise AuthError(message=str(e), error_code=ErrorCode.INVALID_CREDENTIALS)
     except Exception as e:
         # Handle unexpected errors
-        logger.error(f"Unexpected error during login: {str(e)}", exc_info=True)
+        logger.exception("Unexpected error during login: %s", e)
         raise DatabaseError(
             message="An unexpected error occurred. Please try again later.",
-            error_code=ErrorCode.INTERNAL_ERROR
+            error_code=ErrorCode.INTERNAL_ERROR,
         )
 
 
-@router.post("/login/oauth", response_model=Token, operation_id='login_oauth')
+@router.post("/login/oauth", response_model=Token, operation_id="login_oauth")
 @limiter.limit("10/minute")
 async def login_oauth(
-        request: Request,
-        form_data: OAuth2PasswordRequestForm = Depends(),
-        db: AsyncSession = Depends(get_db)
+    request: Request,
+    form_data: OAuth2PasswordRequestForm = Depends(),
+    db: AsyncSession = Depends(get_db),
 ) -> Any:
     """
     OAuth2-compatible login endpoint, used by the OpenAPI UI.
@@ -199,12 +209,14 @@ async def login_oauth(
         Access and refresh tokens.
     """
     try:
-        user = await AuthService.authenticate_user(db, form_data.username, form_data.password)
+        user = await AuthService.authenticate_user(
+            db, form_data.username, form_data.password
+        )
 
         if user is None:
             raise AuthError(
                 message="Invalid email or password",
-                error_code=ErrorCode.INVALID_CREDENTIALS
+                error_code=ErrorCode.INVALID_CREDENTIALS,
             )
 
         # Generate tokens
@@ -216,28 +228,22 @@ async def login_oauth(
         # Return full token response with user data
         return tokens
     except AuthenticationError as e:
-        logger.warning(f"OAuth authentication failed: {str(e)}")
-        raise AuthError(
-            message=str(e),
-            error_code=ErrorCode.INVALID_CREDENTIALS
-        )
-    except AuthError:
-        # Re-raise custom auth exceptions without modification
-        raise
+        logger.warning("OAuth authentication failed: %s", e)
+        raise AuthError(message=str(e), error_code=ErrorCode.INVALID_CREDENTIALS)
     except Exception as e:
-        logger.error(f"Unexpected error during OAuth login: {str(e)}", exc_info=True)
+        logger.exception("Unexpected error during OAuth login: %s", e)
         raise DatabaseError(
             message="An unexpected error occurred. Please try again later.",
-            error_code=ErrorCode.INTERNAL_ERROR
+            error_code=ErrorCode.INTERNAL_ERROR,
         )
 
 
 @router.post("/refresh", response_model=Token, operation_id="refresh_token")
 @limiter.limit("30/minute")
 async def refresh_token(
-        request: Request,
-        refresh_data: RefreshTokenRequest,
-        db: AsyncSession = Depends(get_db)
+    request: Request,
+    refresh_data: RefreshTokenRequest,
+    db: AsyncSession = Depends(get_db),
 ) -> Any:
     """
     Refresh access token using a refresh token.
@@ -249,13 +255,18 @@ async def refresh_token(
     """
     try:
         # Decode the refresh token to get the JTI
-        refresh_payload = decode_token(refresh_data.refresh_token, verify_type="refresh")
+        refresh_payload = decode_token(
+            refresh_data.refresh_token, verify_type="refresh"
+        )
 
         # Check if session exists and is active
-        session = await session_crud.get_active_by_jti(db, jti=refresh_payload.jti)
+        session = await session_service.get_active_by_jti(db, jti=refresh_payload.jti)
 
         if not session:
-            logger.warning(f"Refresh token used for inactive or non-existent session: {refresh_payload.jti}")
+            logger.warning(
+                "Refresh token used for inactive or non-existent session: %s",
+                refresh_payload.jti,
+            )
             raise HTTPException(
                 status_code=status.HTTP_401_UNAUTHORIZED,
                 detail="Session has been revoked. Please log in again.",
@@ -270,14 +281,14 @@ async def refresh_token(
 
         # Update session with new refresh token JTI and expiration
         try:
-            await session_crud.update_refresh_token(
+            await session_service.update_refresh_token(
                 db,
                 session=session,
                 new_jti=new_refresh_payload.jti,
-                new_expires_at=datetime.fromtimestamp(new_refresh_payload.exp, tz=timezone.utc)
+                new_expires_at=datetime.fromtimestamp(new_refresh_payload.exp, tz=UTC),
             )
         except Exception as session_err:
-            logger.error(f"Failed to update session {session.id}: {str(session_err)}", exc_info=True)
+            logger.exception("Failed to update session %s: %s", session.id, session_err)
             # Continue anyway - tokens are already issued
 
         return tokens
@@ -300,10 +311,10 @@ async def refresh_token(
         # Re-raise HTTP exceptions (like session revoked)
         raise
     except Exception as e:
-        logger.error(f"Unexpected error during token refresh: {str(e)}")
+        logger.error("Unexpected error during token refresh: %s", e)
         raise HTTPException(
             status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
-            detail="An unexpected error occurred. Please try again later."
+            detail="An unexpected error occurred. Please try again later.",
         )
 
 
@@ -320,13 +331,13 @@ async def refresh_token(
 
     **Rate Limit**: 3 requests/minute
     """,
-    operation_id="request_password_reset"
+    operation_id="request_password_reset",
 )
 @limiter.limit("3/minute")
 async def request_password_reset(
     request: Request,
     reset_request: PasswordResetRequest,
-    db: AsyncSession = Depends(get_db)
+    db: AsyncSession = Depends(get_db),
 ) -> Any:
     """
     Request a password reset.
@@ -336,7 +347,7 @@ async def request_password_reset(
     """
     try:
         # Look up user by email
-        user = await user_crud.get_by_email(db, email=reset_request.email)
+        user = await user_service.get_by_email(db, email=reset_request.email)
 
         # Only send email if user exists and is active
         if user and user.is_active:
@@ -345,26 +356,27 @@ async def request_password_reset(
 
             # Send password reset email
             await email_service.send_password_reset_email(
-                to_email=user.email,
-                reset_token=reset_token,
-                user_name=user.first_name
+                to_email=user.email, reset_token=reset_token, user_name=user.first_name
             )
-            logger.info(f"Password reset requested for {user.email}")
+            logger.info("Password reset requested for %s", user.email)
         else:
             # Log attempt but don't reveal if email exists
-            logger.warning(f"Password reset requested for non-existent or inactive email: {reset_request.email}")
+            logger.warning(
+                "Password reset requested for non-existent or inactive email: %s",
+                reset_request.email,
+            )
 
         # Always return success to prevent email enumeration
         return MessageResponse(
             success=True,
-            message="If your email is registered, you will receive a password reset link shortly"
+            message="If your email is registered, you will receive a password reset link shortly",
         )
     except Exception as e:
-        logger.error(f"Error processing password reset request: {str(e)}", exc_info=True)
+        logger.exception("Error processing password reset request: %s", e)
         # Still return success to prevent information leakage
         return MessageResponse(
             success=True,
-            message="If your email is registered, you will receive a password reset link shortly"
+            message="If your email is registered, you will receive a password reset link shortly",
         )
 
 
@@ -378,13 +390,13 @@ async def request_password_reset(
 
     **Rate Limit**: 5 requests/minute
     """,
-    operation_id="confirm_password_reset"
+    operation_id="confirm_password_reset",
 )
 @limiter.limit("5/minute")
 async def confirm_password_reset(
     request: Request,
     reset_confirm: PasswordResetConfirm,
-    db: AsyncSession = Depends(get_db)
+    db: AsyncSession = Depends(get_db),
 ) -> Any:
     """
     Confirm password reset with token.
@@ -398,55 +410,52 @@ async def confirm_password_reset(
         if not email:
             raise HTTPException(
                 status_code=status.HTTP_400_BAD_REQUEST,
-                detail="Invalid or expired password reset token"
+                detail="Invalid or expired password reset token",
             )
 
-        # Look up user
-        user = await user_crud.get_by_email(db, email=email)
-
-        if not user:
-            raise HTTPException(
-                status_code=status.HTTP_404_NOT_FOUND,
-                detail="User not found"
+        # Reset password via service (validates user exists and is active)
+        try:
+            user = await AuthService.reset_password(
+                db, email=email, new_password=reset_confirm.new_password
             )
-
-        if not user.is_active:
-            raise HTTPException(
-                status_code=status.HTTP_400_BAD_REQUEST,
-                detail="User account is inactive"
-            )
-
-        # Update password
-        user.password_hash = get_password_hash(reset_confirm.new_password)
-        db.add(user)
-        await db.commit()
+        except AuthenticationError as e:
+            err_msg = str(e)
+            if "inactive" in err_msg.lower():
+                raise HTTPException(
+                    status_code=status.HTTP_400_BAD_REQUEST, detail=err_msg
+                )
+            raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail=err_msg)
 
         # SECURITY: Invalidate all existing sessions after password reset
         # This prevents stolen sessions from being used after password change
-        from app.crud.session import session as session_crud
         try:
-            deactivated_count = await session_crud.deactivate_all_user_sessions(
-                db,
-                user_id=str(user.id)
+            deactivated_count = await session_service.deactivate_all_user_sessions(
+                db, user_id=str(user.id)
+            )
+            logger.info(
+                "Password reset successful for %s, invalidated %s sessions",
+                user.email,
+                deactivated_count,
             )
-            logger.info(f"Password reset successful for {user.email}, invalidated {deactivated_count} sessions")
         except Exception as session_error:
             # Log but don't fail password reset if session invalidation fails
-            logger.error(f"Failed to invalidate sessions after password reset: {str(session_error)}")
+            logger.error(
+                "Failed to invalidate sessions after password reset: %s", session_error
+            )
 
         return MessageResponse(
             success=True,
-            message="Password has been reset successfully. All devices have been logged out for security. You can now log in with your new password."
+            message="Password has been reset successfully. All devices have been logged out for security. You can now log in with your new password.",
         )
 
     except HTTPException:
         raise
     except Exception as e:
-        logger.error(f"Error confirming password reset: {str(e)}", exc_info=True)
+        logger.exception("Error confirming password reset: %s", e)
         await db.rollback()
         raise HTTPException(
             status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
-            detail="An error occurred while resetting your password"
+            detail="An error occurred while resetting your password",
         )
 
 
@@ -464,14 +473,14 @@ async def confirm_password_reset(
 
     **Rate Limit**: 10 requests/minute
     """,
-    operation_id="logout"
+    operation_id="logout",
 )
 @limiter.limit("10/minute")
 async def logout(
     request: Request,
     logout_request: LogoutRequest,
     current_user: User = Depends(get_current_user),
-    db: AsyncSession = Depends(get_db)
+    db: AsyncSession = Depends(get_db),
 ) -> Any:
     """
     Logout from current device by deactivating the session.
@@ -487,57 +496,57 @@ async def logout(
     try:
         # Decode refresh token to get JTI
         try:
-            refresh_payload = decode_token(logout_request.refresh_token, verify_type="refresh")
+            refresh_payload = decode_token(
+                logout_request.refresh_token, verify_type="refresh"
+            )
         except (TokenExpiredError, TokenInvalidError) as e:
             # Even if token is expired/invalid, try to deactivate session
-            logger.warning(f"Logout with invalid/expired token: {str(e)}")
+            logger.warning("Logout with invalid/expired token: %s", e)
             # Don't fail - return success anyway
-            return MessageResponse(
-                success=True,
-                message="Logged out successfully"
-            )
+            return MessageResponse(success=True, message="Logged out successfully")
 
         # Find the session by JTI
-        session = await session_crud.get_by_jti(db, jti=refresh_payload.jti)
+        session = await session_service.get_by_jti(db, jti=refresh_payload.jti)
 
         if session:
             # Verify session belongs to current user (security check)
             if str(session.user_id) != str(current_user.id):
                 logger.warning(
-                    f"User {current_user.id} attempted to logout session {session.id} "
-                    f"belonging to user {session.user_id}"
+                    "User %s attempted to logout session %s belonging to user %s",
+                    current_user.id,
+                    session.id,
+                    session.user_id,
                 )
                 raise HTTPException(
                     status_code=status.HTTP_403_FORBIDDEN,
-                    detail="You can only logout your own sessions"
+                    detail="You can only logout your own sessions",
                 )
 
             # Deactivate the session
-            await session_crud.deactivate(db, session_id=str(session.id))
+            await session_service.deactivate(db, session_id=str(session.id))
 
             logger.info(
-                f"User {current_user.id} logged out from {session.device_name} "
-                f"(session {session.id})"
+                "User %s logged out from %s (session %s)",
+                current_user.id,
+                session.device_name,
+                session.id,
             )
         else:
             # Session not found - maybe already deleted or never existed
             # Return success anyway (idempotent)
-            logger.info(f"Logout requested for non-existent session (JTI: {refresh_payload.jti})")
+            logger.info(
+                "Logout requested for non-existent session (JTI: %s)",
+                refresh_payload.jti,
+            )
 
-        return MessageResponse(
-            success=True,
-            message="Logged out successfully"
-        )
+        return MessageResponse(success=True, message="Logged out successfully")
 
     except HTTPException:
         raise
     except Exception as e:
-        logger.error(f"Error during logout for user {current_user.id}: {str(e)}", exc_info=True)
+        logger.exception("Error during logout for user %s: %s", current_user.id, e)
         # Don't expose error details
-        return MessageResponse(
-            success=True,
-            message="Logged out successfully"
-        )
+        return MessageResponse(success=True, message="Logged out successfully")
 
 
 @router.post(
@@ -553,13 +562,13 @@ async def logout(
 
     **Rate Limit**: 5 requests/minute
     """,
-    operation_id="logout_all"
+    operation_id="logout_all",
 )
 @limiter.limit("5/minute")
 async def logout_all(
     request: Request,
     current_user: User = Depends(get_current_user),
-    db: AsyncSession = Depends(get_db)
+    db: AsyncSession = Depends(get_db),
 ) -> Any:
     """
     Logout from all devices by deactivating all user sessions.
@@ -573,19 +582,23 @@ async def logout_all(
     """
     try:
         # Deactivate all sessions for this user
-        count = await session_crud.deactivate_all_user_sessions(db, user_id=str(current_user.id))
+        count = await session_service.deactivate_all_user_sessions(
+            db, user_id=str(current_user.id)
+        )
 
-        logger.info(f"User {current_user.id} logged out from all devices ({count} sessions)")
+        logger.info(
+            "User %s logged out from all devices (%s sessions)", current_user.id, count
+        )
 
         return MessageResponse(
             success=True,
-            message=f"Successfully logged out from all devices ({count} sessions terminated)"
+            message=f"Successfully logged out from all devices ({count} sessions terminated)",
         )
 
     except Exception as e:
-        logger.error(f"Error during logout-all for user {current_user.id}: {str(e)}", exc_info=True)
+        logger.exception("Error during logout-all for user %s: %s", current_user.id, e)
         await db.rollback()
         raise HTTPException(
             status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
-            detail="An error occurred while logging out"
+            detail="An error occurred while logging out",
         )

backend/app/api/routes/oauth.py

@@ -0,0 +1,434 @@
+# app/api/routes/oauth.py
+"""
+OAuth routes for social authentication.
+
+Endpoints:
+- GET /oauth/providers - List enabled OAuth providers
+- GET /oauth/authorize/{provider} - Get authorization URL
+- POST /oauth/callback/{provider} - Handle OAuth callback
+- GET /oauth/accounts - List linked OAuth accounts
+- DELETE /oauth/accounts/{provider} - Unlink an OAuth account
+"""
+
+import logging
+import os
+from datetime import UTC, datetime
+from typing import Any
+
+from fastapi import APIRouter, Depends, HTTPException, Query, Request, status
+from slowapi import Limiter
+from slowapi.util import get_remote_address
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.api.dependencies.auth import get_current_user, get_optional_current_user
+from app.core.auth import decode_token
+from app.core.config import settings
+from app.core.database import get_db
+from app.core.exceptions import AuthenticationError as AuthError
+from app.models.user import User
+from app.schemas.oauth import (
+    OAuthAccountsListResponse,
+    OAuthCallbackRequest,
+    OAuthCallbackResponse,
+    OAuthProvidersResponse,
+    OAuthUnlinkResponse,
+)
+from app.schemas.sessions import SessionCreate
+from app.schemas.users import Token
+from app.services.oauth_service import OAuthService
+from app.services.session_service import session_service
+from app.utils.device import extract_device_info
+
+router = APIRouter()
+logger = logging.getLogger(__name__)
+
+# Initialize limiter for this router
+limiter = Limiter(key_func=get_remote_address)
+
+# Use higher rate limits in test environment
+IS_TEST = os.getenv("IS_TEST", "False") == "True"
+RATE_MULTIPLIER = 100 if IS_TEST else 1
+
+
+async def _create_oauth_login_session(
+    db: AsyncSession,
+    request: Request,
+    user: User,
+    tokens: Token,
+    provider: str,
+) -> None:
+    """
+    Create a session record for successful OAuth login.
+
+    This is a best-effort operation - login succeeds even if session creation fails.
+    """
+    try:
+        device_info = extract_device_info(request)
+
+        # Decode refresh token to get JTI and expiration
+        refresh_payload = decode_token(tokens.refresh_token, verify_type="refresh")
+
+        session_data = SessionCreate(
+            user_id=user.id,
+            refresh_token_jti=refresh_payload.jti,
+            device_name=device_info.device_name or f"OAuth ({provider})",
+            device_id=device_info.device_id,
+            ip_address=device_info.ip_address,
+            user_agent=device_info.user_agent,
+            last_used_at=datetime.now(UTC),
+            expires_at=datetime.fromtimestamp(refresh_payload.exp, tz=UTC),
+            location_city=device_info.location_city,
+            location_country=device_info.location_country,
+        )
+
+        await session_service.create_session(db, obj_in=session_data)
+
+        logger.info(
+            "OAuth login successful: %s via %s from %s (IP: %s)",
+            user.email,
+            provider,
+            device_info.device_name,
+            device_info.ip_address,
+        )
+    except Exception as session_err:
+        # Log but don't fail login if session creation fails
+        logger.exception(
+            "Failed to create session for OAuth login %s: %s", user.email, session_err
+        )
+
+
+@router.get(
+    "/providers",
+    response_model=OAuthProvidersResponse,
+    summary="List OAuth Providers",
+    description="""
+    Get list of enabled OAuth providers for the login/register UI.
+
+    Returns:
+        List of enabled providers with display info.
+    """,
+    operation_id="list_oauth_providers",
+)
+async def list_providers() -> Any:
+    """
+    Get list of enabled OAuth providers.
+
+    This endpoint is public (no authentication required) as it's needed
+    for the login/register UI to display available social login options.
+    """
+    return OAuthService.get_enabled_providers()
+
+
+@router.get(
+    "/authorize/{provider}",
+    response_model=dict,
+    summary="Get OAuth Authorization URL",
+    description="""
+    Get the authorization URL to redirect the user to the OAuth provider.
+
+    The frontend should redirect the user to the returned URL.
+    After authentication, the provider will redirect back to the callback URL.
+
+    **Rate Limit**: 10 requests/minute
+    """,
+    operation_id="get_oauth_authorization_url",
+)
+@limiter.limit(f"{10 * RATE_MULTIPLIER}/minute")
+async def get_authorization_url(
+    request: Request,
+    provider: str,
+    redirect_uri: str = Query(
+        ..., description="Frontend callback URL after OAuth completes"
+    ),
+    current_user: User | None = Depends(get_optional_current_user),
+    db: AsyncSession = Depends(get_db),
+) -> Any:
+    """
+    Get OAuth authorization URL.
+
+    Args:
+        provider: OAuth provider (google, github)
+        redirect_uri: Frontend callback URL
+        current_user: Current user (optional, for account linking)
+        db: Database session
+
+    Returns:
+        dict with authorization_url and state
+    """
+    if not settings.OAUTH_ENABLED:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="OAuth is not enabled",
+        )
+
+    try:
+        # If user is logged in, this is an account linking flow
+        user_id = str(current_user.id) if current_user else None
+
+        url, state = await OAuthService.create_authorization_url(
+            db,
+            provider=provider,
+            redirect_uri=redirect_uri,
+            user_id=user_id,
+        )
+
+        return {
+            "authorization_url": url,
+            "state": state,
+        }
+
+    except AuthError as e:
+        logger.warning("OAuth authorization failed: %s", e)
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail=str(e),
+        )
+    except Exception as e:
+        logger.exception("OAuth authorization error: %s", e)
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail="Failed to create authorization URL",
+        )
+
+
+@router.post(
+    "/callback/{provider}",
+    response_model=OAuthCallbackResponse,
+    summary="OAuth Callback",
+    description="""
+    Handle OAuth callback from provider.
+
+    The frontend should call this endpoint with the code and state
+    parameters received from the OAuth provider redirect.
+
+    Returns:
+        JWT tokens for the authenticated user.
+
+    **Rate Limit**: 10 requests/minute
+    """,
+    operation_id="handle_oauth_callback",
+)
+@limiter.limit(f"{10 * RATE_MULTIPLIER}/minute")
+async def handle_callback(
+    request: Request,
+    provider: str,
+    callback_data: OAuthCallbackRequest,
+    redirect_uri: str = Query(
+        ..., description="Must match the redirect_uri used in authorization"
+    ),
+    db: AsyncSession = Depends(get_db),
+) -> Any:
+    """
+    Handle OAuth callback.
+
+    Args:
+        provider: OAuth provider (google, github)
+        callback_data: Code and state from provider
+        redirect_uri: Original redirect URI (for validation)
+        db: Database session
+
+    Returns:
+        OAuthCallbackResponse with tokens
+    """
+    if not settings.OAUTH_ENABLED:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="OAuth is not enabled",
+        )
+
+    try:
+        result = await OAuthService.handle_callback(
+            db,
+            code=callback_data.code,
+            state=callback_data.state,
+            redirect_uri=redirect_uri,
+        )
+
+        # Create session for the login (need to get the user first)
+        # Note: This requires fetching the user from the token
+        # For now, we skip session creation here as the result doesn't include user info
+        # The session will be created on next request if needed
+
+        return result
+
+    except AuthError as e:
+        logger.warning("OAuth callback failed: %s", e)
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail=str(e),
+        )
+    except Exception as e:
+        logger.exception("OAuth callback error: %s", e)
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail="OAuth authentication failed",
+        )
+
+
+@router.get(
+    "/accounts",
+    response_model=OAuthAccountsListResponse,
+    summary="List Linked OAuth Accounts",
+    description="""
+    Get list of OAuth accounts linked to the current user.
+
+    Requires authentication.
+    """,
+    operation_id="list_oauth_accounts",
+)
+async def list_accounts(
+    current_user: User = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+) -> Any:
+    """
+    List OAuth accounts linked to the current user.
+
+    Args:
+        current_user: Current authenticated user
+        db: Database session
+
+    Returns:
+        List of linked OAuth accounts
+    """
+    accounts = await OAuthService.get_user_accounts(db, user_id=current_user.id)
+    return OAuthAccountsListResponse(accounts=accounts)
+
+
+@router.delete(
+    "/accounts/{provider}",
+    response_model=OAuthUnlinkResponse,
+    summary="Unlink OAuth Account",
+    description="""
+    Unlink an OAuth provider from the current user.
+
+    The user must have either a password set or another OAuth provider
+    linked to ensure they can still log in.
+
+    **Rate Limit**: 5 requests/minute
+    """,
+    operation_id="unlink_oauth_account",
+)
+@limiter.limit(f"{5 * RATE_MULTIPLIER}/minute")
+async def unlink_account(
+    request: Request,
+    provider: str,
+    current_user: User = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+) -> Any:
+    """
+    Unlink an OAuth provider from the current user.
+
+    Args:
+        provider: Provider to unlink (google, github)
+        current_user: Current authenticated user
+        db: Database session
+
+    Returns:
+        Success message
+    """
+    try:
+        await OAuthService.unlink_provider(
+            db,
+            user=current_user,
+            provider=provider,
+        )
+
+        return OAuthUnlinkResponse(
+            success=True,
+            message=f"{provider.capitalize()} account unlinked successfully",
+        )
+
+    except AuthError as e:
+        logger.warning("OAuth unlink failed for %s: %s", current_user.email, e)
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail=str(e),
+        )
+    except Exception as e:
+        logger.exception("OAuth unlink error: %s", e)
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail="Failed to unlink OAuth account",
+        )
+
+
+@router.post(
+    "/link/{provider}",
+    response_model=dict,
+    summary="Start Account Linking",
+    description="""
+    Start the OAuth flow to link a new provider to the current user.
+
+    This is a convenience endpoint that redirects to /authorize/{provider}
+    with the current user context.
+
+    **Rate Limit**: 10 requests/minute
+    """,
+    operation_id="start_oauth_link",
+)
+@limiter.limit(f"{10 * RATE_MULTIPLIER}/minute")
+async def start_link(
+    request: Request,
+    provider: str,
+    redirect_uri: str = Query(
+        ..., description="Frontend callback URL after OAuth completes"
+    ),
+    current_user: User = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+) -> Any:
+    """
+    Start OAuth account linking flow.
+
+    This endpoint requires authentication and will initiate an OAuth flow
+    to link a new provider to the current user's account.
+
+    Args:
+        provider: OAuth provider to link (google, github)
+        redirect_uri: Frontend callback URL
+        current_user: Current authenticated user
+        db: Database session
+
+    Returns:
+        dict with authorization_url and state
+    """
+    if not settings.OAUTH_ENABLED:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="OAuth is not enabled",
+        )
+
+    # Check if user already has this provider linked
+    existing = await OAuthService.get_user_account_by_provider(
+        db, user_id=current_user.id, provider=provider
+    )
+    if existing:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail=f"You already have a {provider} account linked",
+        )
+
+    try:
+        url, state = await OAuthService.create_authorization_url(
+            db,
+            provider=provider,
+            redirect_uri=redirect_uri,
+            user_id=str(current_user.id),
+        )
+
+        return {
+            "authorization_url": url,
+            "state": state,
+        }
+
+    except AuthError as e:
+        logger.warning("OAuth link authorization failed: %s", e)
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail=str(e),
+        )
+    except Exception as e:
+        logger.exception("OAuth link error: %s", e)
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail="Failed to create authorization URL",
+        )

backend/app/api/routes/oauth_provider.py

@@ -0,0 +1,824 @@
+# app/api/routes/oauth_provider.py
+"""
+OAuth Provider routes (Authorization Server mode) for MCP integration.
+
+Implements OAuth 2.0 Authorization Server endpoints:
+- GET /.well-known/oauth-authorization-server - Server metadata (RFC 8414)
+- GET /oauth/provider/authorize - Authorization endpoint
+- POST /oauth/provider/token - Token endpoint
+- POST /oauth/provider/revoke - Token revocation (RFC 7009)
+- POST /oauth/provider/introspect - Token introspection (RFC 7662)
+- Client management endpoints
+
+Security features:
+- PKCE required for public clients (S256)
+- CSRF protection via state parameter
+- Secure token handling
+- Rate limiting on sensitive endpoints
+"""
+
+import logging
+from typing import Any
+from urllib.parse import urlencode
+
+from fastapi import APIRouter, Depends, Form, HTTPException, Query, Request, status
+from fastapi.responses import RedirectResponse
+from slowapi import Limiter
+from slowapi.util import get_remote_address
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.api.dependencies.auth import (
+    get_current_active_user,
+    get_current_superuser,
+    get_optional_current_user,
+)
+from app.core.config import settings
+from app.core.database import get_db
+from app.models.user import User
+from app.schemas.oauth import (
+    OAuthClientCreate,
+    OAuthClientResponse,
+    OAuthServerMetadata,
+    OAuthTokenIntrospectionResponse,
+    OAuthTokenResponse,
+)
+from app.services import oauth_provider_service as provider_service
+
+router = APIRouter()
+# Separate router for RFC 8414 well-known endpoint (registered at root level)
+wellknown_router = APIRouter()
+logger = logging.getLogger(__name__)
+limiter = Limiter(key_func=get_remote_address)
+
+
+def require_provider_enabled():
+    """Dependency to check if OAuth provider mode is enabled."""
+    if not settings.OAUTH_PROVIDER_ENABLED:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="OAuth provider mode is not enabled. Set OAUTH_PROVIDER_ENABLED=true",
+        )
+
+
+# ============================================================================
+# Server Metadata (RFC 8414)
+# ============================================================================
+
+
+@wellknown_router.get(
+    "/.well-known/oauth-authorization-server",
+    response_model=OAuthServerMetadata,
+    summary="OAuth Server Metadata",
+    description="""
+    OAuth 2.0 Authorization Server Metadata (RFC 8414).
+
+    Returns server metadata including supported endpoints, scopes,
+    and capabilities. MCP clients use this to discover the server.
+
+    Note: This endpoint is at the root level per RFC 8414.
+    """,
+    operation_id="get_oauth_server_metadata",
+    tags=["OAuth Provider"],
+)
+async def get_server_metadata(
+    _: None = Depends(require_provider_enabled),
+) -> OAuthServerMetadata:
+    """Get OAuth 2.0 server metadata."""
+    base_url = settings.OAUTH_ISSUER.rstrip("/")
+
+    return OAuthServerMetadata(
+        issuer=base_url,
+        authorization_endpoint=f"{base_url}/api/v1/oauth/provider/authorize",
+        token_endpoint=f"{base_url}/api/v1/oauth/provider/token",
+        revocation_endpoint=f"{base_url}/api/v1/oauth/provider/revoke",
+        introspection_endpoint=f"{base_url}/api/v1/oauth/provider/introspect",
+        registration_endpoint=None,  # Dynamic registration not supported
+        scopes_supported=[
+            "openid",
+            "profile",
+            "email",
+            "read:users",
+            "write:users",
+            "read:organizations",
+            "write:organizations",
+            "admin",
+        ],
+        response_types_supported=["code"],
+        grant_types_supported=["authorization_code", "refresh_token"],
+        code_challenge_methods_supported=["S256"],
+        token_endpoint_auth_methods_supported=[
+            "client_secret_basic",
+            "client_secret_post",
+            "none",  # For public clients with PKCE
+        ],
+    )
+
+
+# ============================================================================
+# Authorization Endpoint
+# ============================================================================
+
+
+@router.get(
+    "/provider/authorize",
+    summary="Authorization Endpoint",
+    description="""
+    OAuth 2.0 Authorization Endpoint.
+
+    Initiates the authorization code flow:
+    1. Validates client and parameters
+    2. Checks if user is authenticated (redirects to login if not)
+    3. Checks existing consent
+    4. Redirects to consent page if needed
+    5. Issues authorization code and redirects back to client
+
+    Required parameters:
+    - response_type: Must be "code"
+    - client_id: Registered client ID
+    - redirect_uri: Must match registered URI
+
+    Recommended parameters:
+    - state: CSRF protection
+    - code_challenge + code_challenge_method: PKCE (required for public clients)
+    - scope: Requested permissions
+    """,
+    operation_id="oauth_provider_authorize",
+    tags=["OAuth Provider"],
+)
+@limiter.limit("30/minute")
+async def authorize(
+    request: Request,
+    response_type: str = Query(..., description="Must be 'code'"),
+    client_id: str = Query(..., description="OAuth client ID"),
+    redirect_uri: str = Query(..., description="Redirect URI"),
+    scope: str = Query(default="", description="Requested scopes (space-separated)"),
+    state: str = Query(default="", description="CSRF state parameter"),
+    code_challenge: str | None = Query(default=None, description="PKCE code challenge"),
+    code_challenge_method: str | None = Query(
+        default=None, description="PKCE method (S256)"
+    ),
+    nonce: str | None = Query(default=None, description="OpenID Connect nonce"),
+    db: AsyncSession = Depends(get_db),
+    _: None = Depends(require_provider_enabled),
+    current_user: User | None = Depends(get_optional_current_user),
+) -> Any:
+    """
+    Authorization endpoint - initiates OAuth flow.
+
+    If user is not authenticated, redirects to login with return URL.
+    If user has not consented, redirects to consent page.
+    If all checks pass, generates code and redirects to client.
+    """
+    # Validate response_type
+    if response_type != "code":
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="invalid_request: response_type must be 'code'",
+        )
+
+    # Validate PKCE method if provided - ONLY S256 is allowed (RFC 7636 Section 4.3)
+    # "plain" method provides no security benefit and MUST NOT be used
+    if code_challenge_method and code_challenge_method != "S256":
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="invalid_request: code_challenge_method must be 'S256' (plain is not supported)",
+        )
+
+    # Validate client
+    try:
+        client = await provider_service.get_client(db, client_id)
+        if not client:
+            raise provider_service.InvalidClientError("Unknown client_id")
+        provider_service.validate_redirect_uri(client, redirect_uri)
+    except provider_service.OAuthProviderError as e:
+        # For client/redirect errors, we can't safely redirect - show error
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail=f"{e.error}: {e.error_description}",
+        )
+
+    # Validate and filter scopes
+    try:
+        requested_scopes = provider_service.parse_scope(scope)
+        valid_scopes = provider_service.validate_scopes(client, requested_scopes)
+    except provider_service.InvalidScopeError as e:
+        # Redirect with error
+        scope_error_params: dict[str, str] = {"error": e.error}
+        if e.error_description:
+            scope_error_params["error_description"] = e.error_description
+        if state:
+            scope_error_params["state"] = state
+        return RedirectResponse(
+            url=f"{redirect_uri}?{urlencode(scope_error_params)}",
+            status_code=status.HTTP_302_FOUND,
+        )
+
+    # Public clients MUST use PKCE
+    if client.client_type == "public":
+        if not code_challenge or code_challenge_method != "S256":
+            pkce_error_params: dict[str, str] = {
+                "error": "invalid_request",
+                "error_description": "PKCE with S256 is required for public clients",
+            }
+            if state:
+                pkce_error_params["state"] = state
+            return RedirectResponse(
+                url=f"{redirect_uri}?{urlencode(pkce_error_params)}",
+                status_code=status.HTTP_302_FOUND,
+            )
+
+    # If user is not authenticated, redirect to login
+    if not current_user:
+        # Store authorization request in session and redirect to login
+        # The frontend will handle the return URL
+        login_url = f"{settings.FRONTEND_URL}/login"
+        return_params = urlencode(
+            {
+                "oauth_authorize": "true",
+                "client_id": client_id,
+                "redirect_uri": redirect_uri,
+                "scope": " ".join(valid_scopes),
+                "state": state,
+                "code_challenge": code_challenge or "",
+                "code_challenge_method": code_challenge_method or "",
+                "nonce": nonce or "",
+            }
+        )
+        return RedirectResponse(
+            url=f"{login_url}?return_to=/auth/consent?{return_params}",
+            status_code=status.HTTP_302_FOUND,
+        )
+
+    # Check if user has already consented
+    has_consent = await provider_service.check_consent(
+        db, current_user.id, client_id, valid_scopes
+    )
+
+    if not has_consent:
+        # Redirect to consent page
+        consent_params = urlencode(
+            {
+                "client_id": client_id,
+                "client_name": client.client_name,
+                "redirect_uri": redirect_uri,
+                "scope": " ".join(valid_scopes),
+                "state": state,
+                "code_challenge": code_challenge or "",
+                "code_challenge_method": code_challenge_method or "",
+                "nonce": nonce or "",
+            }
+        )
+        return RedirectResponse(
+            url=f"{settings.FRONTEND_URL}/auth/consent?{consent_params}",
+            status_code=status.HTTP_302_FOUND,
+        )
+
+    # User is authenticated and has consented - issue authorization code
+    try:
+        code = await provider_service.create_authorization_code(
+            db=db,
+            client=client,
+            user=current_user,
+            redirect_uri=redirect_uri,
+            scope=" ".join(valid_scopes),
+            code_challenge=code_challenge,
+            code_challenge_method=code_challenge_method,
+            state=state,
+            nonce=nonce,
+        )
+    except provider_service.OAuthProviderError as e:
+        error_params: dict[str, str] = {"error": e.error}
+        if e.error_description:
+            error_params["error_description"] = e.error_description
+        if state:
+            error_params["state"] = state
+        return RedirectResponse(
+            url=f"{redirect_uri}?{urlencode(error_params)}",
+            status_code=status.HTTP_302_FOUND,
+        )
+
+    # Success - redirect with code
+    success_params = {"code": code}
+    if state:
+        success_params["state"] = state
+
+    return RedirectResponse(
+        url=f"{redirect_uri}?{urlencode(success_params)}",
+        status_code=status.HTTP_302_FOUND,
+    )
+
+
+@router.post(
+    "/provider/authorize/consent",
+    summary="Submit Authorization Consent",
+    description="""
+    Submit user consent for OAuth authorization.
+
+    Called by the consent page after user approves or denies.
+    """,
+    operation_id="oauth_provider_consent",
+    tags=["OAuth Provider"],
+)
+@limiter.limit("30/minute")
+async def submit_consent(
+    request: Request,
+    approved: bool = Form(..., description="Whether user approved"),
+    client_id: str = Form(..., description="OAuth client ID"),
+    redirect_uri: str = Form(..., description="Redirect URI"),
+    scope: str = Form(default="", description="Granted scopes"),
+    state: str = Form(default="", description="CSRF state parameter"),
+    code_challenge: str | None = Form(default=None),
+    code_challenge_method: str | None = Form(default=None),
+    nonce: str | None = Form(default=None),
+    db: AsyncSession = Depends(get_db),
+    _: None = Depends(require_provider_enabled),
+    current_user: User = Depends(get_current_active_user),
+) -> Any:
+    """Process consent form submission."""
+    # Validate client
+    try:
+        client = await provider_service.get_client(db, client_id)
+        if not client:
+            raise provider_service.InvalidClientError("Unknown client_id")
+        provider_service.validate_redirect_uri(client, redirect_uri)
+    except provider_service.OAuthProviderError as e:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail=f"{e.error}: {e.error_description}",
+        )
+
+    # If user denied, redirect with error
+    if not approved:
+        denied_params: dict[str, str] = {
+            "error": "access_denied",
+            "error_description": "User denied authorization",
+        }
+        if state:
+            denied_params["state"] = state
+        return RedirectResponse(
+            url=f"{redirect_uri}?{urlencode(denied_params)}",
+            status_code=status.HTTP_302_FOUND,
+        )
+
+    # Parse and validate scopes
+    granted_scopes = provider_service.parse_scope(scope)
+    valid_scopes = provider_service.validate_scopes(client, granted_scopes)
+
+    # Record consent
+    await provider_service.grant_consent(db, current_user.id, client_id, valid_scopes)
+
+    # Generate authorization code
+    try:
+        code = await provider_service.create_authorization_code(
+            db=db,
+            client=client,
+            user=current_user,
+            redirect_uri=redirect_uri,
+            scope=" ".join(valid_scopes),
+            code_challenge=code_challenge,
+            code_challenge_method=code_challenge_method,
+            state=state,
+            nonce=nonce,
+        )
+    except provider_service.OAuthProviderError as e:
+        error_params: dict[str, str] = {"error": e.error}
+        if e.error_description:
+            error_params["error_description"] = e.error_description
+        if state:
+            error_params["state"] = state
+        return RedirectResponse(
+            url=f"{redirect_uri}?{urlencode(error_params)}",
+            status_code=status.HTTP_302_FOUND,
+        )
+
+    # Success
+    success_params = {"code": code}
+    if state:
+        success_params["state"] = state
+
+    return RedirectResponse(
+        url=f"{redirect_uri}?{urlencode(success_params)}",
+        status_code=status.HTTP_302_FOUND,
+    )
+
+
+# ============================================================================
+# Token Endpoint
+# ============================================================================
+
+
+@router.post(
+    "/provider/token",
+    response_model=OAuthTokenResponse,
+    summary="Token Endpoint",
+    description="""
+    OAuth 2.0 Token Endpoint.
+
+    Supports:
+    - authorization_code: Exchange code for tokens
+    - refresh_token: Refresh access token
+
+    Client authentication:
+    - Confidential clients: client_secret (Basic auth or POST body)
+    - Public clients: No secret, but PKCE code_verifier required
+    """,
+    operation_id="oauth_provider_token",
+    tags=["OAuth Provider"],
+)
+@limiter.limit("60/minute")
+async def token(
+    request: Request,
+    grant_type: str = Form(..., description="Grant type"),
+    code: str | None = Form(default=None, description="Authorization code"),
+    redirect_uri: str | None = Form(default=None, description="Redirect URI"),
+    client_id: str | None = Form(default=None, description="Client ID"),
+    client_secret: str | None = Form(default=None, description="Client secret"),
+    code_verifier: str | None = Form(default=None, description="PKCE code verifier"),
+    refresh_token: str | None = Form(default=None, description="Refresh token"),
+    scope: str | None = Form(default=None, description="Scope (for refresh)"),
+    db: AsyncSession = Depends(get_db),
+    _: None = Depends(require_provider_enabled),
+) -> OAuthTokenResponse:
+    """Token endpoint - exchange code for tokens or refresh."""
+    # Extract client credentials from Basic auth if not in body
+    if not client_id:
+        auth_header = request.headers.get("Authorization", "")
+        if auth_header.startswith("Basic "):
+            import base64
+
+            try:
+                decoded = base64.b64decode(auth_header[6:]).decode()
+                client_id, client_secret = decoded.split(":", 1)
+            except Exception as e:
+                # Log malformed Basic auth for security monitoring
+                logger.warning(
+                    "Malformed Basic auth header in token request: %s", type(e).__name__
+                )
+                # Fall back to form body
+
+    if not client_id:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="invalid_client: client_id required",
+            headers={"WWW-Authenticate": "Basic"},
+        )
+
+    # Get device info
+    device_info = request.headers.get("User-Agent", "")[:500]
+    ip_address = get_remote_address(request)
+
+    try:
+        if grant_type == "authorization_code":
+            if not code:
+                raise provider_service.InvalidRequestError("code required")
+            if not redirect_uri:
+                raise provider_service.InvalidRequestError("redirect_uri required")
+
+            result = await provider_service.exchange_authorization_code(
+                db=db,
+                code=code,
+                client_id=client_id,
+                redirect_uri=redirect_uri,
+                code_verifier=code_verifier,
+                client_secret=client_secret,
+                device_info=device_info,
+                ip_address=ip_address,
+            )
+
+        elif grant_type == "refresh_token":
+            if not refresh_token:
+                raise provider_service.InvalidRequestError("refresh_token required")
+
+            result = await provider_service.refresh_tokens(
+                db=db,
+                refresh_token=refresh_token,
+                client_id=client_id,
+                client_secret=client_secret,
+                scope=scope,
+                device_info=device_info,
+                ip_address=ip_address,
+            )
+
+        else:
+            raise HTTPException(
+                status_code=status.HTTP_400_BAD_REQUEST,
+                detail="unsupported_grant_type: Must be authorization_code or refresh_token",
+            )
+
+        return OAuthTokenResponse(**result)
+
+    except provider_service.InvalidClientError as e:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail=f"{e.error}: {e.error_description}",
+            headers={"WWW-Authenticate": "Basic"},
+        )
+    except provider_service.OAuthProviderError as e:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail=f"{e.error}: {e.error_description}",
+        )
+
+
+# ============================================================================
+# Token Revocation (RFC 7009)
+# ============================================================================
+
+
+@router.post(
+    "/provider/revoke",
+    status_code=status.HTTP_200_OK,
+    summary="Token Revocation Endpoint",
+    description="""
+    OAuth 2.0 Token Revocation Endpoint (RFC 7009).
+
+    Revokes an access token or refresh token.
+    Always returns 200 OK (even if token is invalid) per spec.
+    """,
+    operation_id="oauth_provider_revoke",
+    tags=["OAuth Provider"],
+)
+@limiter.limit("30/minute")
+async def revoke(
+    request: Request,
+    token: str = Form(..., description="Token to revoke"),
+    token_type_hint: str | None = Form(
+        default=None, description="Token type hint (access_token, refresh_token)"
+    ),
+    client_id: str | None = Form(default=None, description="Client ID"),
+    client_secret: str | None = Form(default=None, description="Client secret"),
+    db: AsyncSession = Depends(get_db),
+    _: None = Depends(require_provider_enabled),
+) -> dict[str, str]:
+    """Revoke a token."""
+    # Extract client credentials from Basic auth if not in body
+    if not client_id:
+        auth_header = request.headers.get("Authorization", "")
+        if auth_header.startswith("Basic "):
+            import base64
+
+            try:
+                decoded = base64.b64decode(auth_header[6:]).decode()
+                client_id, client_secret = decoded.split(":", 1)
+            except Exception as e:
+                # Log malformed Basic auth for security monitoring
+                logger.warning(
+                    "Malformed Basic auth header in revoke request: %s",
+                    type(e).__name__,
+                )
+                # Fall back to form body
+
+    try:
+        await provider_service.revoke_token(
+            db=db,
+            token=token,
+            token_type_hint=token_type_hint,
+            client_id=client_id,
+            client_secret=client_secret,
+        )
+    except provider_service.InvalidClientError:
+        # Per RFC 7009, we should return 200 OK even for errors
+        # But client authentication errors can return 401
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="invalid_client",
+            headers={"WWW-Authenticate": "Basic"},
+        )
+    except Exception as e:
+        # Log but don't expose errors per RFC 7009
+        logger.warning("Token revocation error: %s", e)
+
+    # Always return 200 OK per RFC 7009
+    return {"status": "ok"}
+
+
+# ============================================================================
+# Token Introspection (RFC 7662)
+# ============================================================================
+
+
+@router.post(
+    "/provider/introspect",
+    response_model=OAuthTokenIntrospectionResponse,
+    summary="Token Introspection Endpoint",
+    description="""
+    OAuth 2.0 Token Introspection Endpoint (RFC 7662).
+
+    Allows resource servers to query the authorization server
+    to determine the active state and metadata of a token.
+    """,
+    operation_id="oauth_provider_introspect",
+    tags=["OAuth Provider"],
+)
+@limiter.limit("120/minute")
+async def introspect(
+    request: Request,
+    token: str = Form(..., description="Token to introspect"),
+    token_type_hint: str | None = Form(
+        default=None, description="Token type hint (access_token, refresh_token)"
+    ),
+    client_id: str | None = Form(default=None, description="Client ID"),
+    client_secret: str | None = Form(default=None, description="Client secret"),
+    db: AsyncSession = Depends(get_db),
+    _: None = Depends(require_provider_enabled),
+) -> OAuthTokenIntrospectionResponse:
+    """Introspect a token."""
+    # Extract client credentials from Basic auth if not in body
+    if not client_id:
+        auth_header = request.headers.get("Authorization", "")
+        if auth_header.startswith("Basic "):
+            import base64
+
+            try:
+                decoded = base64.b64decode(auth_header[6:]).decode()
+                client_id, client_secret = decoded.split(":", 1)
+            except Exception as e:
+                # Log malformed Basic auth for security monitoring
+                logger.warning(
+                    "Malformed Basic auth header in introspect request: %s",
+                    type(e).__name__,
+                )
+                # Fall back to form body
+
+    try:
+        result = await provider_service.introspect_token(
+            db=db,
+            token=token,
+            token_type_hint=token_type_hint,
+            client_id=client_id,
+            client_secret=client_secret,
+        )
+        return OAuthTokenIntrospectionResponse(**result)
+    except provider_service.InvalidClientError:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="invalid_client",
+            headers={"WWW-Authenticate": "Basic"},
+        )
+    except Exception as e:
+        logger.warning("Token introspection error: %s", e)
+        return OAuthTokenIntrospectionResponse(active=False)  # pyright: ignore[reportCallIssue]
+
+
+# ============================================================================
+# Client Management (Admin)
+# ============================================================================
+
+
+@router.post(
+    "/provider/clients",
+    response_model=dict,
+    summary="Register OAuth Client",
+    description="""
+    Register a new OAuth client (admin only).
+
+    Creates an MCP client that can authenticate against this API.
+    Returns client_id and client_secret (for confidential clients).
+
+    **Important:** Store the client_secret securely - it won't be shown again!
+    """,
+    operation_id="register_oauth_client",
+    tags=["OAuth Provider Admin"],
+)
+async def register_client(
+    client_name: str = Form(..., description="Client application name"),
+    redirect_uris: str = Form(..., description="Comma-separated redirect URIs"),
+    client_type: str = Form(default="public", description="public or confidential"),
+    scopes: str = Form(
+        default="openid profile email",
+        description="Allowed scopes (space-separated)",
+    ),
+    mcp_server_url: str | None = Form(default=None, description="MCP server URL"),
+    db: AsyncSession = Depends(get_db),
+    _: None = Depends(require_provider_enabled),
+    current_user: User = Depends(get_current_superuser),
+) -> dict:
+    """Register a new OAuth client."""
+    # Parse redirect URIs
+    uris = [uri.strip() for uri in redirect_uris.split(",") if uri.strip()]
+    if not uris:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="At least one redirect_uri is required",
+        )
+
+    # Parse scopes
+    allowed_scopes = [s.strip() for s in scopes.split() if s.strip()]
+
+    client_data = OAuthClientCreate(
+        client_name=client_name,
+        client_description=None,
+        redirect_uris=uris,
+        allowed_scopes=allowed_scopes,
+        client_type=client_type,
+    )
+
+    client, secret = await provider_service.register_client(db, client_data)
+
+    # Update MCP server URL if provided
+    if mcp_server_url:
+        client.mcp_server_url = mcp_server_url
+        await db.commit()
+
+    result = {
+        "client_id": client.client_id,
+        "client_name": client.client_name,
+        "client_type": client.client_type,
+        "redirect_uris": client.redirect_uris,
+        "allowed_scopes": client.allowed_scopes,
+    }
+
+    if secret:
+        result["client_secret"] = secret
+        result["warning"] = (
+            "Store the client_secret securely! It will not be shown again."
+        )
+
+    return result
+
+
+@router.get(
+    "/provider/clients",
+    response_model=list[OAuthClientResponse],
+    summary="List OAuth Clients",
+    description="List all registered OAuth clients (admin only).",
+    operation_id="list_oauth_clients",
+    tags=["OAuth Provider Admin"],
+)
+async def list_clients(
+    db: AsyncSession = Depends(get_db),
+    _: None = Depends(require_provider_enabled),
+    current_user: User = Depends(get_current_superuser),
+) -> list[OAuthClientResponse]:
+    """List all OAuth clients."""
+    clients = await provider_service.list_clients(db)
+    return [OAuthClientResponse.model_validate(c) for c in clients]
+
+
+@router.delete(
+    "/provider/clients/{client_id}",
+    status_code=status.HTTP_204_NO_CONTENT,
+    summary="Delete OAuth Client",
+    description="Delete an OAuth client (admin only). Revokes all tokens.",
+    operation_id="delete_oauth_client",
+    tags=["OAuth Provider Admin"],
+)
+async def delete_client(
+    client_id: str,
+    db: AsyncSession = Depends(get_db),
+    _: None = Depends(require_provider_enabled),
+    current_user: User = Depends(get_current_superuser),
+) -> None:
+    """Delete an OAuth client."""
+    client = await provider_service.get_client(db, client_id)
+    if not client:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Client not found",
+        )
+
+    await provider_service.delete_client_by_id(db, client_id=client_id)
+
+
+# ============================================================================
+# User Consent Management
+# ============================================================================
+
+
+@router.get(
+    "/provider/consents",
+    summary="List My Consents",
+    description="List OAuth applications the current user has authorized.",
+    operation_id="list_my_oauth_consents",
+    tags=["OAuth Provider"],
+)
+async def list_my_consents(
+    db: AsyncSession = Depends(get_db),
+    _: None = Depends(require_provider_enabled),
+    current_user: User = Depends(get_current_active_user),
+) -> list[dict]:
+    """List applications the user has authorized."""
+    return await provider_service.list_user_consents(db, user_id=current_user.id)
+
+
+@router.delete(
+    "/provider/consents/{client_id}",
+    status_code=status.HTTP_204_NO_CONTENT,
+    summary="Revoke My Consent",
+    description="Revoke authorization for an OAuth application. Also revokes all tokens.",
+    operation_id="revoke_my_oauth_consent",
+    tags=["OAuth Provider"],
+)
+async def revoke_my_consent(
+    client_id: str,
+    db: AsyncSession = Depends(get_db),
+    _: None = Depends(require_provider_enabled),
+    current_user: User = Depends(get_current_active_user),
+) -> None:
+    """Revoke consent for an application."""
+    revoked = await provider_service.revoke_consent(db, current_user.id, client_id)
+    if not revoked:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="No consent found for this client",
+        )

backend/app/api/routes/organizations.py

@@ -4,8 +4,9 @@ Organization endpoints for regular users.
 
 These endpoints allow users to view and manage organizations they belong to.
 """
+
 import logging
-from typing import Any, List
+from typing import Any
 from uuid import UUID
 
 from fastapi import APIRouter, Depends, Query
@@ -14,19 +15,18 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from app.api.dependencies.auth import get_current_user
 from app.api.dependencies.permissions import require_org_admin, require_org_membership
 from app.core.database import get_db
-from app.core.exceptions import NotFoundError, ErrorCode
-from app.crud.organization import organization as organization_crud
 from app.models.user import User
 from app.schemas.common import (
-    PaginationParams,
     PaginatedResponse,
-    create_pagination_meta
+    PaginationParams,
+    create_pagination_meta,
 )
 from app.schemas.organizations import (
-    OrganizationResponse,
     OrganizationMemberResponse,
-    OrganizationUpdate
+    OrganizationResponse,
+    OrganizationUpdate,
 )
+from app.services.organization_service import organization_service
 
 logger = logging.getLogger(__name__)
 
@@ -35,15 +35,15 @@ router = APIRouter()
 
 @router.get(
     "/me",
-    response_model=List[OrganizationResponse],
+    response_model=list[OrganizationResponse],
     summary="Get My Organizations",
     description="Get all organizations the current user belongs to",
-    operation_id="get_my_organizations"
+    operation_id="get_my_organizations",
 )
 async def get_my_organizations(
     is_active: bool = Query(True, description="Filter by active membership"),
     current_user: User = Depends(get_current_user),
-    db: AsyncSession = Depends(get_db)
+    db: AsyncSession = Depends(get_db),
 ) -> Any:
     """
     Get all organizations the current user belongs to.
@@ -53,16 +53,14 @@ async def get_my_organizations(
     """
     try:
         # Get all org data in single query with JOIN and subquery
-        orgs_data = await organization_crud.get_user_organizations_with_details(
-            db,
-            user_id=current_user.id,
-            is_active=is_active
+        orgs_data = await organization_service.get_user_organizations_with_details(
+            db, user_id=current_user.id, is_active=is_active
         )
 
         # Transform to response objects
         orgs_with_data = []
         for item in orgs_data:
-            org = item['organization']
+            org = item["organization"]
             org_dict = {
                 "id": org.id,
                 "name": org.name,
@@ -72,14 +70,14 @@ async def get_my_organizations(
                 "settings": org.settings,
                 "created_at": org.created_at,
                 "updated_at": org.updated_at,
-                "member_count": item['member_count']
+                "member_count": item["member_count"],
             }
             orgs_with_data.append(OrganizationResponse(**org_dict))
 
         return orgs_with_data
 
     except Exception as e:
-        logger.error(f"Error getting user organizations: {str(e)}", exc_info=True)
+        logger.exception("Error getting user organizations: %s", e)
         raise
 
 
@@ -88,12 +86,12 @@ async def get_my_organizations(
     response_model=OrganizationResponse,
     summary="Get Organization Details",
     description="Get details of an organization the user belongs to",
-    operation_id="get_organization"
+    operation_id="get_organization",
 )
 async def get_organization(
     organization_id: UUID,
     current_user: User = Depends(require_org_membership),
-    db: AsyncSession = Depends(get_db)
+    db: AsyncSession = Depends(get_db),
 ) -> Any:
     """
     Get details of a specific organization.
@@ -101,13 +99,7 @@ async def get_organization(
     User must be a member of the organization.
     """
     try:
-        org = await organization_crud.get(db, id=organization_id)
-        if not org:  # pragma: no cover - Permission check prevents this (see docs/UNREACHABLE_DEFENSIVE_CODE_ANALYSIS.md)
-            raise NotFoundError(
-                detail=f"Organization {organization_id} not found",
-                error_code=ErrorCode.NOT_FOUND
-            )
-
+        org = await organization_service.get_organization(db, str(organization_id))
         org_dict = {
             "id": org.id,
             "name": org.name,
@@ -117,14 +109,14 @@ async def get_organization(
             "settings": org.settings,
             "created_at": org.created_at,
             "updated_at": org.updated_at,
-            "member_count": await organization_crud.get_member_count(db, organization_id=org.id)
+            "member_count": await organization_service.get_member_count(
+                db, organization_id=org.id
+            ),
         }
         return OrganizationResponse(**org_dict)
 
-    except NotFoundError:  # pragma: no cover - See above
-        raise
     except Exception as e:
-        logger.error(f"Error getting organization: {str(e)}", exc_info=True)
+        logger.exception("Error getting organization: %s", e)
         raise
 
 
@@ -133,14 +125,14 @@ async def get_organization(
     response_model=PaginatedResponse[OrganizationMemberResponse],
     summary="Get Organization Members",
     description="Get all members of an organization (members can view)",
-    operation_id="get_organization_members"
+    operation_id="get_organization_members",
 )
 async def get_organization_members(
     organization_id: UUID,
     pagination: PaginationParams = Depends(),
     is_active: bool = Query(True, description="Filter by active status"),
     current_user: User = Depends(require_org_membership),
-    db: AsyncSession = Depends(get_db)
+    db: AsyncSession = Depends(get_db),
 ) -> Any:
     """
     Get all members of an organization.
@@ -148,12 +140,12 @@ async def get_organization_members(
     User must be a member of the organization to view members.
     """
     try:
-        members, total = await organization_crud.get_organization_members(
+        members, total = await organization_service.get_organization_members(
             db,
             organization_id=organization_id,
             skip=pagination.offset,
             limit=pagination.limit,
-            is_active=is_active
+            is_active=is_active,
         )
 
         member_responses = [OrganizationMemberResponse(**member) for member in members]
@@ -162,13 +154,13 @@ async def get_organization_members(
             total=total,
             page=pagination.page,
             limit=pagination.limit,
-            items_count=len(member_responses)
+            items_count=len(member_responses),
         )
 
         return PaginatedResponse(data=member_responses, pagination=pagination_meta)
 
     except Exception as e:
-        logger.error(f"Error getting organization members: {str(e)}", exc_info=True)
+        logger.exception("Error getting organization members: %s", e)
         raise
 
 
@@ -177,13 +169,13 @@ async def get_organization_members(
     response_model=OrganizationResponse,
     summary="Update Organization",
     description="Update organization details (admin/owner only)",
-    operation_id="update_organization"
+    operation_id="update_organization",
 )
 async def update_organization(
     organization_id: UUID,
     org_in: OrganizationUpdate,
     current_user: User = Depends(require_org_admin),
-    db: AsyncSession = Depends(get_db)
+    db: AsyncSession = Depends(get_db),
 ) -> Any:
     """
     Update organization details.
@@ -191,15 +183,13 @@ async def update_organization(
     Requires owner or admin role in the organization.
     """
     try:
-        org = await organization_crud.get(db, id=organization_id)
-        if not org:  # pragma: no cover - Permission check prevents this (see docs/UNREACHABLE_DEFENSIVE_CODE_ANALYSIS.md)
-            raise NotFoundError(
-                detail=f"Organization {organization_id} not found",
-                error_code=ErrorCode.NOT_FOUND
-            )
-
-        updated_org = await organization_crud.update(db, db_obj=org, obj_in=org_in)
-        logger.info(f"User {current_user.email} updated organization {updated_org.name}")
+        org = await organization_service.get_organization(db, str(organization_id))
+        updated_org = await organization_service.update_organization(
+            db, org=org, obj_in=org_in
+        )
+        logger.info(
+            "User %s updated organization %s", current_user.email, updated_org.name
+        )
 
         org_dict = {
             "id": updated_org.id,
@@ -210,12 +200,12 @@ async def update_organization(
             "settings": updated_org.settings,
             "created_at": updated_org.created_at,
             "updated_at": updated_org.updated_at,
-            "member_count": await organization_crud.get_member_count(db, organization_id=updated_org.id)
+            "member_count": await organization_service.get_member_count(
+                db, organization_id=updated_org.id
+            ),
         }
         return OrganizationResponse(**org_dict)
 
-    except NotFoundError:  # pragma: no cover - See above
-        raise
     except Exception as e:
-        logger.error(f"Error updating organization: {str(e)}", exc_info=True)
+        logger.exception("Error updating organization: %s", e)
         raise

backend/app/api/routes/sessions.py

@@ -3,11 +3,12 @@ Session management endpoints.
 
 Allows users to view and manage their active sessions across devices.
 """
+
 import logging
 from typing import Any
 from uuid import UUID
 
-from fastapi import APIRouter, Depends, HTTPException, status, Request
+from fastapi import APIRouter, Depends, HTTPException, Request, status
 from slowapi import Limiter
 from slowapi.util import get_remote_address
 from sqlalchemy.ext.asyncio import AsyncSession
@@ -15,11 +16,11 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from app.api.dependencies.auth import get_current_user
 from app.core.auth import decode_token
 from app.core.database import get_db
-from app.core.exceptions import NotFoundError, AuthorizationError, ErrorCode
-from app.crud.session import session as session_crud
+from app.core.exceptions import AuthorizationError, ErrorCode, NotFoundError
 from app.models.user import User
 from app.schemas.common import MessageResponse
-from app.schemas.sessions import SessionResponse, SessionListResponse
+from app.schemas.sessions import SessionListResponse, SessionResponse
+from app.services.session_service import session_service
 
 router = APIRouter()
 logger = logging.getLogger(__name__)
@@ -39,13 +40,13 @@ limiter = Limiter(key_func=get_remote_address)
 
     **Rate Limit**: 30 requests/minute
     """,
-    operation_id="list_my_sessions"
+    operation_id="list_my_sessions",
 )
 @limiter.limit("30/minute")
 async def list_my_sessions(
     request: Request,
     current_user: User = Depends(get_current_user),
-    db: AsyncSession = Depends(get_db)
+    db: AsyncSession = Depends(get_db),
 ) -> Any:
     """
     List all active sessions for the current user.
@@ -59,23 +60,21 @@ async def list_my_sessions(
     """
     try:
         # Get all active sessions for user
-        sessions = await session_crud.get_user_sessions(
-            db,
-            user_id=str(current_user.id),
-            active_only=True
+        sessions = await session_service.get_user_sessions(
+            db, user_id=str(current_user.id), active_only=True
         )
 
         # Try to identify current session from Authorization header
-        current_session_jti = None
         auth_header = request.headers.get("authorization")
         if auth_header and auth_header.startswith("Bearer "):
             try:
                 access_token = auth_header.split(" ")[1]
-                token_payload = decode_token(access_token)
+                decode_token(access_token)
                 # Note: Access tokens don't have JTI by default, but we can try
                 # For now, we'll mark current based on most recent activity
-            except Exception:
-                pass
+            except Exception as e:
+                # Optional token parsing - silently ignore failures
+                logger.debug("Failed to decode access token for session marking: %s", e)
 
         # Convert to response format
         session_responses = []
@@ -90,22 +89,25 @@ async def list_my_sessions(
                 last_used_at=s.last_used_at,
                 created_at=s.created_at,
                 expires_at=s.expires_at,
-                is_current=(s == sessions[0] if sessions else False)  # Most recent = current
+                is_current=(
+                    s == sessions[0] if sessions else False
+                ),  # Most recent = current
             )
             session_responses.append(session_response)
 
-        logger.info(f"User {current_user.id} listed {len(session_responses)} active sessions")
+        logger.info(
+            "User %s listed %s active sessions", current_user.id, len(session_responses)
+        )
 
         return SessionListResponse(
-            sessions=session_responses,
-            total=len(session_responses)
+            sessions=session_responses, total=len(session_responses)
         )
 
     except Exception as e:
-        logger.error(f"Error listing sessions for user {current_user.id}: {str(e)}", exc_info=True)
+        logger.exception("Error listing sessions for user %s: %s", current_user.id, e)
         raise HTTPException(
             status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
-            detail="Failed to retrieve sessions"
+            detail="Failed to retrieve sessions",
         )
 
 
@@ -122,14 +124,14 @@ async def list_my_sessions(
 
     **Rate Limit**: 10 requests/minute
     """,
-    operation_id="revoke_session"
+    operation_id="revoke_session",
 )
 @limiter.limit("10/minute")
 async def revoke_session(
     request: Request,
     session_id: UUID,
     current_user: User = Depends(get_current_user),
-    db: AsyncSession = Depends(get_db)
+    db: AsyncSession = Depends(get_db),
 ) -> Any:
     """
     Revoke a specific session by ID.
@@ -144,45 +146,49 @@ async def revoke_session(
     """
     try:
         # Get the session
-        session = await session_crud.get(db, id=str(session_id))
+        session = await session_service.get_session(db, str(session_id))
 
         if not session:
             raise NotFoundError(
                 message=f"Session {session_id} not found",
-                error_code=ErrorCode.NOT_FOUND
+                error_code=ErrorCode.NOT_FOUND,
             )
 
         # Verify session belongs to current user
         if str(session.user_id) != str(current_user.id):
             logger.warning(
-                f"User {current_user.id} attempted to revoke session {session_id} "
-                f"belonging to user {session.user_id}"
+                "User %s attempted to revoke session %s belonging to user %s",
+                current_user.id,
+                session_id,
+                session.user_id,
             )
             raise AuthorizationError(
                 message="You can only revoke your own sessions",
-                error_code=ErrorCode.INSUFFICIENT_PERMISSIONS
+                error_code=ErrorCode.INSUFFICIENT_PERMISSIONS,
             )
 
         # Deactivate the session
-        await session_crud.deactivate(db, session_id=str(session_id))
+        await session_service.deactivate(db, session_id=str(session_id))
 
         logger.info(
-            f"User {current_user.id} revoked session {session_id} "
-            f"({session.device_name})"
+            "User %s revoked session %s (%s)",
+            current_user.id,
+            session_id,
+            session.device_name,
         )
 
         return MessageResponse(
             success=True,
-            message=f"Session revoked: {session.device_name or 'Unknown device'}"
+            message=f"Session revoked: {session.device_name or 'Unknown device'}",
         )
 
     except (NotFoundError, AuthorizationError):
         raise
     except Exception as e:
-        logger.error(f"Error revoking session {session_id}: {str(e)}", exc_info=True)
+        logger.exception("Error revoking session %s: %s", session_id, e)
         raise HTTPException(
             status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
-            detail="Failed to revoke session"
+            detail="Failed to revoke session",
         )
 
 
@@ -198,13 +204,13 @@ async def revoke_session(
 
     **Rate Limit**: 5 requests/minute
     """,
-    operation_id="cleanup_expired_sessions"
+    operation_id="cleanup_expired_sessions",
 )
 @limiter.limit("5/minute")
 async def cleanup_expired_sessions(
     request: Request,
     current_user: User = Depends(get_current_user),
-    db: AsyncSession = Depends(get_db)
+    db: AsyncSession = Depends(get_db),
 ) -> Any:
     """
     Cleanup expired sessions for the current user.
@@ -218,22 +224,24 @@ async def cleanup_expired_sessions(
     """
     try:
         # Use optimized bulk DELETE instead of N individual deletes
-        deleted_count = await session_crud.cleanup_expired_for_user(
-            db,
-            user_id=str(current_user.id)
+        deleted_count = await session_service.cleanup_expired_for_user(
+            db, user_id=str(current_user.id)
         )
 
-        logger.info(f"User {current_user.id} cleaned up {deleted_count} expired sessions")
+        logger.info(
+            "User %s cleaned up %s expired sessions", current_user.id, deleted_count
+        )
 
         return MessageResponse(
-            success=True,
-            message=f"Cleaned up {deleted_count} expired sessions"
+            success=True, message=f"Cleaned up {deleted_count} expired sessions"
         )
 
     except Exception as e:
-        logger.error(f"Error cleaning up sessions for user {current_user.id}: {str(e)}", exc_info=True)
+        logger.exception(
+            "Error cleaning up sessions for user %s: %s", current_user.id, e
+        )
         await db.rollback()
         raise HTTPException(
             status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
-            detail="Failed to cleanup sessions"
+            detail="Failed to cleanup sessions",
         )

backend/app/api/routes/users.py

@@ -1,33 +1,30 @@
 """
-User management endpoints for CRUD operations.
+User management endpoints for database operations.
 """
+
 import logging
-from typing import Any, Optional
+from typing import Any
 from uuid import UUID
 
-from fastapi import APIRouter, Depends, Query, status, Request
+from fastapi import APIRouter, Depends, Query, Request, status
 from slowapi import Limiter
 from slowapi.util import get_remote_address
 from sqlalchemy.ext.asyncio import AsyncSession
 
-from app.api.dependencies.auth import get_current_user, get_current_superuser
+from app.api.dependencies.auth import get_current_superuser, get_current_user
 from app.core.database import get_db
-from app.core.exceptions import (
-    NotFoundError,
-    AuthorizationError,
-    ErrorCode
-)
-from app.crud.user import user as user_crud
+from app.core.exceptions import AuthorizationError, ErrorCode
 from app.models.user import User
 from app.schemas.common import (
-    PaginationParams,
-    PaginatedResponse,
     MessageResponse,
+    PaginatedResponse,
+    PaginationParams,
     SortParams,
-    create_pagination_meta
+    create_pagination_meta,
 )
-from app.schemas.users import UserResponse, UserUpdate, PasswordChange
-from app.services.auth_service import AuthService, AuthenticationError
+from app.schemas.users import PasswordChange, UserResponse, UserUpdate
+from app.services.auth_service import AuthenticationError, AuthService
+from app.services.user_service import user_service
 
 logger = logging.getLogger(__name__)
 
@@ -50,15 +47,15 @@ limiter = Limiter(key_func=get_remote_address)
 
     **Rate Limit**: 60 requests/minute
     """,
-    operation_id="list_users"
+    operation_id="list_users",
 )
 async def list_users(
     pagination: PaginationParams = Depends(),
     sort: SortParams = Depends(),
-    is_active: Optional[bool] = Query(None, description="Filter by active status"),
-    is_superuser: Optional[bool] = Query(None, description="Filter by superuser status"),
+    is_active: bool | None = Query(None, description="Filter by active status"),
+    is_superuser: bool | None = Query(None, description="Filter by superuser status"),
     current_user: User = Depends(get_current_superuser),
-    db: AsyncSession = Depends(get_db)
+    db: AsyncSession = Depends(get_db),
 ) -> Any:
     """
     List all users with pagination, filtering, and sorting.
@@ -74,13 +71,13 @@ async def list_users(
             filters["is_superuser"] = is_superuser
 
         # Get paginated users with total count
-        users, total = await user_crud.get_multi_with_total(
+        users, total = await user_service.list_users(
             db,
             skip=pagination.offset,
             limit=pagination.limit,
             sort_by=sort.sort_by,
             sort_order=sort.sort_order.value if sort.sort_order else "asc",
-            filters=filters if filters else None
+            filters=filters if filters else None,
         )
 
         # Create pagination metadata
@@ -88,15 +85,12 @@ async def list_users(
             total=total,
             page=pagination.page,
             limit=pagination.limit,
-            items_count=len(users)
+            items_count=len(users),
         )
 
-        return PaginatedResponse(
-            data=users,
-            pagination=pagination_meta
-        )
+        return PaginatedResponse(data=users, pagination=pagination_meta)
     except Exception as e:
-        logger.error(f"Error listing users: {str(e)}", exc_info=True)
+        logger.exception("Error listing users: %s", e)
         raise
 
 
@@ -111,10 +105,10 @@ async def list_users(
 
     **Rate Limit**: 60 requests/minute
     """,
-    operation_id="get_current_user_profile"
+    operation_id="get_current_user_profile",
 )
-def get_current_user_profile(
-    current_user: User = Depends(get_current_user)
+async def get_current_user_profile(
+    current_user: User = Depends(get_current_user),
 ) -> Any:
     """Get current user's profile."""
     return current_user
@@ -133,12 +127,12 @@ def get_current_user_profile(
 
     **Rate Limit**: 30 requests/minute
     """,
-    operation_id="update_current_user"
+    operation_id="update_current_user",
 )
 async def update_current_user(
     user_update: UserUpdate,
     current_user: User = Depends(get_current_user),
-    db: AsyncSession = Depends(get_db)
+    db: AsyncSession = Depends(get_db),
 ) -> Any:
     """
     Update current user's profile.
@@ -146,18 +140,16 @@ async def update_current_user(
     Users cannot elevate their own permissions (protected by UserUpdate schema validator).
     """
     try:
-        updated_user = await user_crud.update(
-            db,
-            db_obj=current_user,
-            obj_in=user_update
+        updated_user = await user_service.update_user(
+            db, user=current_user, obj_in=user_update
         )
-        logger.info(f"User {current_user.id} updated their profile")
+        logger.info("User %s updated their profile", current_user.id)
         return updated_user
     except ValueError as e:
-        logger.error(f"Error updating user {current_user.id}: {str(e)}")
+        logger.error("Error updating user %s: %s", current_user.id, e)
         raise
     except Exception as e:
-        logger.error(f"Unexpected error updating user {current_user.id}: {str(e)}", exc_info=True)
+        logger.exception("Unexpected error updating user %s: %s", current_user.id, e)
         raise
 
 
@@ -175,12 +167,12 @@ async def update_current_user(
 
     **Rate Limit**: 60 requests/minute
     """,
-    operation_id="get_user_by_id"
+    operation_id="get_user_by_id",
 )
 async def get_user_by_id(
     user_id: UUID,
     current_user: User = Depends(get_current_user),
-    db: AsyncSession = Depends(get_db)
+    db: AsyncSession = Depends(get_db),
 ) -> Any:
     """
     Get user by ID.
@@ -190,21 +182,17 @@ async def get_user_by_id(
     # Check permissions
     if str(user_id) != str(current_user.id) and not current_user.is_superuser:
         logger.warning(
-            f"User {current_user.id} attempted to access user {user_id} without permission"
+            "User %s attempted to access user %s without permission",
+            current_user.id,
+            user_id,
         )
         raise AuthorizationError(
             message="Not enough permissions to view this user",
-            error_code=ErrorCode.INSUFFICIENT_PERMISSIONS
+            error_code=ErrorCode.INSUFFICIENT_PERMISSIONS,
         )
 
     # Get user
-    user = await user_crud.get(db, id=str(user_id))
-    if not user:
-        raise NotFoundError(
-            message=f"User with id {user_id} not found",
-            error_code=ErrorCode.USER_NOT_FOUND
-        )
-
+    user = await user_service.get_user(db, str(user_id))
     return user
 
 
@@ -222,13 +210,13 @@ async def get_user_by_id(
 
     **Rate Limit**: 30 requests/minute
     """,
-    operation_id="update_user"
+    operation_id="update_user",
 )
 async def update_user(
     user_id: UUID,
     user_update: UserUpdate,
     current_user: User = Depends(get_current_user),
-    db: AsyncSession = Depends(get_db)
+    db: AsyncSession = Depends(get_db),
 ) -> Any:
     """
     Update user by ID.
@@ -241,30 +229,27 @@ async def update_user(
 
     if not is_own_profile and not current_user.is_superuser:
         logger.warning(
-            f"User {current_user.id} attempted to update user {user_id} without permission"
+            "User %s attempted to update user %s without permission",
+            current_user.id,
+            user_id,
         )
         raise AuthorizationError(
             message="Not enough permissions to update this user",
-            error_code=ErrorCode.INSUFFICIENT_PERMISSIONS
+            error_code=ErrorCode.INSUFFICIENT_PERMISSIONS,
         )
 
     # Get user
-    user = await user_crud.get(db, id=str(user_id))
-    if not user:
-        raise NotFoundError(
-            message=f"User with id {user_id} not found",
-            error_code=ErrorCode.USER_NOT_FOUND
-        )
+    user = await user_service.get_user(db, str(user_id))
 
     try:
-        updated_user = await user_crud.update(db, db_obj=user, obj_in=user_update)
-        logger.info(f"User {user_id} updated by {current_user.id}")
+        updated_user = await user_service.update_user(db, user=user, obj_in=user_update)
+        logger.info("User %s updated by %s", user_id, current_user.id)
         return updated_user
     except ValueError as e:
-        logger.error(f"Error updating user {user_id}: {str(e)}")
+        logger.error("Error updating user %s: %s", user_id, e)
         raise
     except Exception as e:
-        logger.error(f"Unexpected error updating user {user_id}: {str(e)}", exc_info=True)
+        logger.exception("Unexpected error updating user %s: %s", user_id, e)
         raise
 
 
@@ -281,14 +266,14 @@ async def update_user(
 
     **Rate Limit**: 5 requests/minute
     """,
-    operation_id="change_current_user_password"
+    operation_id="change_current_user_password",
 )
 @limiter.limit("5/minute")
 async def change_current_user_password(
     request: Request,
     password_change: PasswordChange,
     current_user: User = Depends(get_current_user),
-    db: AsyncSession = Depends(get_db)
+    db: AsyncSession = Depends(get_db),
 ) -> Any:
     """
     Change current user's password.
@@ -300,23 +285,23 @@ async def change_current_user_password(
             db=db,
             user_id=current_user.id,
             current_password=password_change.current_password,
-            new_password=password_change.new_password
+            new_password=password_change.new_password,
         )
 
         if success:
-            logger.info(f"User {current_user.id} changed their password")
+            logger.info("User %s changed their password", current_user.id)
             return MessageResponse(
-                success=True,
-                message="Password changed successfully"
+                success=True, message="Password changed successfully"
             )
     except AuthenticationError as e:
-        logger.warning(f"Failed password change attempt for user {current_user.id}: {str(e)}")
+        logger.warning(
+            "Failed password change attempt for user %s: %s", current_user.id, e
+        )
         raise AuthorizationError(
-            message=str(e),
-            error_code=ErrorCode.INVALID_CREDENTIALS
+            message=str(e), error_code=ErrorCode.INVALID_CREDENTIALS
         )
     except Exception as e:
-        logger.error(f"Error changing password for user {current_user.id}: {str(e)}")
+        logger.error("Error changing password for user %s: %s", current_user.id, e)
         raise
 
 
@@ -335,12 +320,12 @@ async def change_current_user_password(
 
     **Note**: This performs a hard delete. Consider implementing soft deletes for production.
     """,
-    operation_id="delete_user"
+    operation_id="delete_user",
 )
 async def delete_user(
     user_id: UUID,
     current_user: User = Depends(get_current_superuser),
-    db: AsyncSession = Depends(get_db)
+    db: AsyncSession = Depends(get_db),
 ) -> Any:
     """
     Delete user by ID (superuser only).
@@ -351,28 +336,22 @@ async def delete_user(
     if str(user_id) == str(current_user.id):
         raise AuthorizationError(
             message="Cannot delete your own account",
-            error_code=ErrorCode.INSUFFICIENT_PERMISSIONS
+            error_code=ErrorCode.INSUFFICIENT_PERMISSIONS,
         )
 
-    # Get user
-    user = await user_crud.get(db, id=str(user_id))
-    if not user:
-        raise NotFoundError(
-            message=f"User with id {user_id} not found",
-            error_code=ErrorCode.USER_NOT_FOUND
-        )
+    # Get user (raises NotFoundError if not found)
+    await user_service.get_user(db, str(user_id))
 
     try:
         # Use soft delete instead of hard delete
-        await user_crud.soft_delete(db, id=str(user_id))
-        logger.info(f"User {user_id} soft-deleted by {current_user.id}")
+        await user_service.soft_delete_user(db, str(user_id))
+        logger.info("User %s soft-deleted by %s", user_id, current_user.id)
         return MessageResponse(
-            success=True,
-            message=f"User {user_id} deleted successfully"
+            success=True, message=f"User {user_id} deleted successfully"
         )
     except ValueError as e:
-        logger.error(f"Error deleting user {user_id}: {str(e)}")
+        logger.error("Error deleting user %s: %s", user_id, e)
         raise
     except Exception as e:
-        logger.error(f"Unexpected error deleting user {user_id}: {str(e)}", exc_info=True)
+        logger.exception("Unexpected error deleting user %s: %s", user_id, e)
         raise

backend/app/core/auth.py

@@ -1,49 +1,50 @@
-import logging
-logging.getLogger('passlib').setLevel(logging.ERROR)
-
-from datetime import datetime, timedelta, timezone
-from typing import Any, Dict, Optional, Union
-import uuid
 import asyncio
+import uuid
+from datetime import UTC, datetime, timedelta
 from functools import partial
+from typing import Any
 
-from jose import jwt, JWTError
-from passlib.context import CryptContext
+import bcrypt
+import jwt
+from jwt.exceptions import (
+    ExpiredSignatureError,
+    InvalidTokenError,
+    MissingRequiredClaimError,
+)
 from pydantic import ValidationError
 
 from app.core.config import settings
 from app.schemas.users import TokenData, TokenPayload
 
 
-# Password hashing context
-pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
-
 # Custom exceptions for auth
 class AuthError(Exception):
     """Base authentication error"""
-    pass
+
 
 class TokenExpiredError(AuthError):
     """Token has expired"""
-    pass
+
 
 class TokenInvalidError(AuthError):
     """Token is invalid"""
-    pass
+
 
 class TokenMissingClaimError(AuthError):
     """Token is missing a required claim"""
-    pass
 
 
 def verify_password(plain_password: str, hashed_password: str) -> bool:
-    """Verify a password against a hash."""
-    return pwd_context.verify(plain_password, hashed_password)
+    """Verify a password against a bcrypt hash."""
+    return bcrypt.checkpw(
+        plain_password.encode("utf-8"), hashed_password.encode("utf-8")
+    )
 
 
 def get_password_hash(password: str) -> str:
-    """Generate a password hash."""
-    return pwd_context.hash(password)
+    """Generate a bcrypt password hash."""
+    salt = bcrypt.gensalt()
+    return bcrypt.hashpw(password.encode("utf-8"), salt).decode("utf-8")
 
 
 async def verify_password_async(plain_password: str, hashed_password: str) -> bool:
@@ -60,10 +61,9 @@ async def verify_password_async(plain_password: str, hashed_password: str) -> bo
     Returns:
         True if password matches, False otherwise
     """
-    loop = asyncio.get_event_loop()
+    loop = asyncio.get_running_loop()
     return await loop.run_in_executor(
-        None,
-        partial(pwd_context.verify, plain_password, hashed_password)
+        None, partial(verify_password, plain_password, hashed_password)
     )
 
 
@@ -81,18 +81,14 @@ async def get_password_hash_async(password: str) -> str:
     Returns:
         Hashed password string
     """
-    loop = asyncio.get_event_loop()
-    return await loop.run_in_executor(
-        None,
-        pwd_context.hash,
-        password
-    )
+    loop = asyncio.get_running_loop()
+    return await loop.run_in_executor(None, get_password_hash, password)
 
 
 def create_access_token(
-        subject: Union[str, Any],
-        expires_delta: Optional[timedelta] = None,
-        claims: Optional[Dict[str, Any]] = None
+    subject: str | Any,
+    expires_delta: timedelta | None = None,
+    claims: dict[str, Any] | None = None,
 ) -> str:
     """
     Create a JWT access token.
@@ -106,17 +102,19 @@ def create_access_token(
         Encoded JWT token
     """
     if expires_delta:
-        expire = datetime.now(timezone.utc) + expires_delta
+        expire = datetime.now(UTC) + expires_delta
     else:
-        expire = datetime.now(timezone.utc) + timedelta(minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES)
+        expire = datetime.now(UTC) + timedelta(
+            minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES
+        )
 
     # Base token data
     to_encode = {
         "sub": str(subject),
         "exp": expire,
-        "iat": datetime.now(tz=timezone.utc),
+        "iat": datetime.now(tz=UTC),
         "jti": str(uuid.uuid4()),
-        "type": "access"
+        "type": "access",
     }
 
     # Add custom claims
@@ -124,18 +122,11 @@ def create_access_token(
         to_encode.update(claims)
 
     # Create the JWT
-    encoded_jwt = jwt.encode(
-        to_encode,
-        settings.SECRET_KEY,
-        algorithm=settings.ALGORITHM
-    )
-
-    return encoded_jwt
+    return jwt.encode(to_encode, settings.SECRET_KEY, algorithm=settings.ALGORITHM)
 
 
 def create_refresh_token(
-        subject: Union[str, Any],
-        expires_delta: Optional[timedelta] = None
+    subject: str | Any, expires_delta: timedelta | None = None
 ) -> str:
     """
     Create a JWT refresh token.
@@ -148,28 +139,22 @@ def create_refresh_token(
         Encoded JWT refresh token
     """
     if expires_delta:
-        expire = datetime.now(timezone.utc) + expires_delta
+        expire = datetime.now(UTC) + expires_delta
     else:
-        expire = datetime.now(timezone.utc) + timedelta(days=settings.REFRESH_TOKEN_EXPIRE_DAYS)
+        expire = datetime.now(UTC) + timedelta(days=settings.REFRESH_TOKEN_EXPIRE_DAYS)
 
     to_encode = {
         "sub": str(subject),
         "exp": expire,
-        "iat": datetime.now(timezone.utc),
+        "iat": datetime.now(UTC),
         "jti": str(uuid.uuid4()),
-        "type": "refresh"
+        "type": "refresh",
     }
 
-    encoded_jwt = jwt.encode(
-        to_encode,
-        settings.SECRET_KEY,
-        algorithm=settings.ALGORITHM
-    )
-
-    return encoded_jwt
+    return jwt.encode(to_encode, settings.SECRET_KEY, algorithm=settings.ALGORITHM)
 
 
-def decode_token(token: str, verify_type: Optional[str] = None) -> TokenPayload:
+def decode_token(token: str, verify_type: str | None = None) -> TokenPayload:
     """
     Decode and verify a JWT token.
 
@@ -195,8 +180,8 @@ def decode_token(token: str, verify_type: Optional[str] = None) -> TokenPayload:
                 "verify_signature": True,
                 "verify_exp": True,
                 "verify_iat": True,
-                "require": ["exp", "sub", "iat"]
-            }
+                "require": ["exp", "sub", "iat"],
+            },
         )
 
         # SECURITY: Explicitly verify the algorithm to prevent algorithm confusion attacks
@@ -206,7 +191,7 @@ def decode_token(token: str, verify_type: Optional[str] = None) -> TokenPayload:
 
         # Reject weak or unexpected algorithms
         # NOTE: These are defensive checks that provide defense-in-depth.
-        # The python-jose library rejects these tokens BEFORE we reach here,
+        # PyJWT rejects these tokens BEFORE we reach here,
         # but we keep these checks in case the library changes or is misconfigured.
         # Coverage: Marked as pragma since library catches first (see tests/core/test_auth_security.py)
         if token_algorithm == "NONE":  # pragma: no cover
@@ -227,10 +212,11 @@ def decode_token(token: str, verify_type: Optional[str] = None) -> TokenPayload:
         token_data = TokenPayload(**payload)
         return token_data
 
-    except JWTError as e:
-        # Check if the error is due to an expired token
-        if "expired" in str(e).lower():
-            raise TokenExpiredError("Token has expired")
+    except ExpiredSignatureError:
+        raise TokenExpiredError("Token has expired")
+    except MissingRequiredClaimError as e:
+        raise TokenMissingClaimError(f"Token missing required claim: {e}")
+    except InvalidTokenError:
         raise TokenInvalidError("Invalid authentication token")
     except ValidationError:
         raise TokenInvalidError("Invalid token payload")
@@ -250,4 +236,4 @@ def get_token_data(token: str) -> TokenData:
     user_id = payload.sub
     is_superuser = payload.is_superuser or False
 
-    return TokenData(user_id=uuid.UUID(user_id), is_superuser=is_superuser)
+    return TokenData(user_id=uuid.UUID(user_id), is_superuser=is_superuser)

backend/app/core/config.py

@@ -1,19 +1,22 @@
 import logging
-from typing import Optional, List
 
 from pydantic import Field, field_validator
 from pydantic_settings import BaseSettings
 
 
 class Settings(BaseSettings):
-    PROJECT_NAME: str = "App"
+    PROJECT_NAME: str = "PragmaStack"
     VERSION: str = "1.0.0"
     API_V1_STR: str = "/api/v1"
 
     # Environment (must be before SECRET_KEY for validation)
     ENVIRONMENT: str = Field(
         default="development",
-        description="Environment: development, staging, or production"
+        description="Environment: development, staging, or production",
+    )
+    DEMO_MODE: bool = Field(
+        default=False,
+        description="Enable demo mode (relaxed security, demo users)",
     )
 
     # Security: Content Security Policy
@@ -21,8 +24,7 @@ class Settings(BaseSettings):
     # Set to True for strict CSP (blocks most external resources)
     # Set to "relaxed" for modern frontend development
     CSP_MODE: str = Field(
-        default="relaxed",
-        description="CSP mode: 'strict', 'relaxed', or 'disabled'"
+        default="relaxed", description="CSP mode: 'strict', 'relaxed', or 'disabled'"
     )
 
     # Database configuration
@@ -31,7 +33,7 @@ class Settings(BaseSettings):
     POSTGRES_HOST: str = "localhost"
     POSTGRES_PORT: str = "5432"
     POSTGRES_DB: str = "app"
-    DATABASE_URL: Optional[str] = None
+    DATABASE_URL: str | None = None
     db_pool_size: int = 20  # Default connection pool size
     db_max_overflow: int = 50  # Maximum overflow connections
     db_pool_timeout: int = 30  # Seconds to wait for a connection
@@ -59,38 +61,90 @@ class Settings(BaseSettings):
     SECRET_KEY: str = Field(
         default="dev_only_insecure_key_change_in_production_32chars_min",
         min_length=32,
-        description="JWT signing key. MUST be changed in production. Generate with: python -c 'import secrets; print(secrets.token_urlsafe(32))'"
+        description="JWT signing key. MUST be changed in production. Generate with: python -c 'import secrets; print(secrets.token_urlsafe(32))'",
     )
     ALGORITHM: str = "HS256"
     ACCESS_TOKEN_EXPIRE_MINUTES: int = 15  # 15 minutes (production standard)
     REFRESH_TOKEN_EXPIRE_DAYS: int = 7  # 7 days
 
     # CORS configuration
-    BACKEND_CORS_ORIGINS: List[str] = ["http://localhost:3000"]
+    BACKEND_CORS_ORIGINS: list[str] = ["http://localhost:3000"]
 
     # Frontend URL for email links
     FRONTEND_URL: str = Field(
         default="http://localhost:3000",
-        description="Frontend application URL for email links"
+        description="Frontend application URL for email links",
     )
 
+    # OAuth Configuration
+    OAUTH_ENABLED: bool = Field(
+        default=False,
+        description="Enable OAuth authentication (social login)",
+    )
+    OAUTH_AUTO_LINK_BY_EMAIL: bool = Field(
+        default=True,
+        description="Automatically link OAuth accounts to existing users with matching email",
+    )
+    OAUTH_STATE_EXPIRE_MINUTES: int = Field(
+        default=10,
+        description="OAuth state parameter expiration time in minutes",
+    )
+
+    # Google OAuth
+    OAUTH_GOOGLE_CLIENT_ID: str | None = Field(
+        default=None,
+        description="Google OAuth client ID from Google Cloud Console",
+    )
+    OAUTH_GOOGLE_CLIENT_SECRET: str | None = Field(
+        default=None,
+        description="Google OAuth client secret from Google Cloud Console",
+    )
+
+    # GitHub OAuth
+    OAUTH_GITHUB_CLIENT_ID: str | None = Field(
+        default=None,
+        description="GitHub OAuth client ID from GitHub Developer Settings",
+    )
+    OAUTH_GITHUB_CLIENT_SECRET: str | None = Field(
+        default=None,
+        description="GitHub OAuth client secret from GitHub Developer Settings",
+    )
+
+    # OAuth Provider Mode (for MCP clients - skeleton)
+    OAUTH_PROVIDER_ENABLED: bool = Field(
+        default=False,
+        description="Enable OAuth provider mode (act as authorization server for MCP clients)",
+    )
+    OAUTH_ISSUER: str = Field(
+        default="http://localhost:8000",
+        description="OAuth issuer URL (your API base URL)",
+    )
+
+    @property
+    def enabled_oauth_providers(self) -> list[str]:
+        """Get list of enabled OAuth providers based on configured credentials."""
+        providers = []
+        if self.OAUTH_GOOGLE_CLIENT_ID and self.OAUTH_GOOGLE_CLIENT_SECRET:
+            providers.append("google")
+        if self.OAUTH_GITHUB_CLIENT_ID and self.OAUTH_GITHUB_CLIENT_SECRET:
+            providers.append("github")
+        return providers
+
     # Admin user
-    FIRST_SUPERUSER_EMAIL: Optional[str] = Field(
-        default=None,
-        description="Email for first superuser account"
+    FIRST_SUPERUSER_EMAIL: str | None = Field(
+        default=None, description="Email for first superuser account"
     )
-    FIRST_SUPERUSER_PASSWORD: Optional[str] = Field(
-        default=None,
-        description="Password for first superuser (min 12 characters)"
+    FIRST_SUPERUSER_PASSWORD: str | None = Field(
+        default=None, description="Password for first superuser (min 12 characters)"
     )
 
-    @field_validator('SECRET_KEY')
+    @field_validator("SECRET_KEY")
     @classmethod
     def validate_secret_key(cls, v: str, info) -> str:
         """Validate SECRET_KEY is secure, especially in production."""
         # Get environment from values if available
         values_data = info.data if info.data else {}
-        env = values_data.get('ENVIRONMENT', 'development')
+        env = values_data.get("ENVIRONMENT", "development")
 
         if v.startswith("your_secret_key_here"):
             if env == "production":
@@ -106,22 +160,40 @@ class Settings(BaseSettings):
             )
 
         if len(v) < 32:
-            raise ValueError("SECRET_KEY must be at least 32 characters long for security")
+            raise ValueError(
+                "SECRET_KEY must be at least 32 characters long for security"
+            )
 
         return v
 
-    @field_validator('FIRST_SUPERUSER_PASSWORD')
+    @field_validator("FIRST_SUPERUSER_PASSWORD")
     @classmethod
-    def validate_superuser_password(cls, v: Optional[str]) -> Optional[str]:
+    def validate_superuser_password(cls, v: str | None, info) -> str | None:
         """Validate superuser password strength."""
         if v is None:
             return v
 
+        # Get environment from values if available
+        values_data = info.data if info.data else {}
+        demo_mode = values_data.get("DEMO_MODE", False)
+
+        if demo_mode:
+            # In demo mode, allow specific weak passwords for demo accounts
+            demo_passwords = {"Demo123!", "Admin123!"}
+            if v in demo_passwords:
+                return v
+
         if len(v) < 12:
             raise ValueError("FIRST_SUPERUSER_PASSWORD must be at least 12 characters")
 
         # Check for common weak passwords
-        weak_passwords = {'admin123', 'Admin123', 'password123', 'Password123', '123456789012'}
+        weak_passwords = {
+            "admin123",
+            "Admin123",
+            "password123",
+            "Password123",
+            "123456789012",
+        }
         if v in weak_passwords:
             raise ValueError(
                 "FIRST_SUPERUSER_PASSWORD is too weak. "
@@ -144,8 +216,8 @@ class Settings(BaseSettings):
         "env_file": "../.env",
         "env_file_encoding": "utf-8",
         "case_sensitive": True,
-        "extra": "ignore"  # Ignore extra fields from .env (e.g., frontend-specific vars)
+        "extra": "ignore",  # Ignore extra fields from .env (e.g., frontend-specific vars)
     }
 
 
-settings = Settings()
+settings = Settings()

backend/app/core/database.py

@@ -5,17 +5,18 @@ Database configuration using SQLAlchemy 2.0 and asyncpg.
 This module provides async database connectivity with proper connection pooling
 and session management for FastAPI endpoints.
 """
+
 import logging
+from collections.abc import AsyncGenerator
 from contextlib import asynccontextmanager
-from typing import AsyncGenerator
 
 from sqlalchemy import text
 from sqlalchemy.dialects.postgresql import JSONB, UUID
 from sqlalchemy.ext.asyncio import (
-    AsyncSession,
     AsyncEngine,
-    create_async_engine,
+    AsyncSession,
     async_sessionmaker,
+    create_async_engine,
 )
 from sqlalchemy.ext.compiler import compiles
 from sqlalchemy.orm import DeclarativeBase
@@ -27,12 +28,12 @@ logger = logging.getLogger(__name__)
 
 
 # SQLite compatibility for testing
-@compiles(JSONB, 'sqlite')
+@compiles(JSONB, "sqlite")
 def compile_jsonb_sqlite(type_, compiler, **kw):
     return "TEXT"
 
 
-@compiles(UUID, 'sqlite')
+@compiles(UUID, "sqlite")
 def compile_uuid_sqlite(type_, compiler, **kw):
     return "TEXT"
 
@@ -40,7 +41,6 @@ def compile_uuid_sqlite(type_, compiler, **kw):
 # Declarative base for models (SQLAlchemy 2.0 style)
 class Base(DeclarativeBase):
     """Base class for all database models."""
-    pass
 
 
 def get_async_database_url(url: str) -> str:
@@ -75,7 +75,7 @@ def create_async_production_engine() -> AsyncEngine:
 
     # Add PostgreSQL-specific connect_args
     if "postgresql" in async_url:
-        engine_config["connect_args"] = {
+        engine_config["connect_args"] = {  # type: ignore[assignment]
             "server_settings": {
                 "application_name": settings.PROJECT_NAME,
                 "timezone": "UTC",
@@ -128,8 +128,8 @@ async def async_transaction_scope() -> AsyncGenerator[AsyncSession, None]:
 
     Usage:
         async with async_transaction_scope() as db:
-            user = await user_crud.create(db, obj_in=user_create)
-            profile = await profile_crud.create(db, obj_in=profile_create)
+            user = await user_repo.create(db, obj_in=user_create)
+            profile = await profile_repo.create(db, obj_in=profile_create)
             # Both operations committed together
     """
     async with SessionLocal() as session:
@@ -139,7 +139,7 @@ async def async_transaction_scope() -> AsyncGenerator[AsyncSession, None]:
             logger.debug("Async transaction committed successfully")
         except Exception as e:
             await session.rollback()
-            logger.error(f"Async transaction failed, rolling back: {str(e)}")
+            logger.error("Async transaction failed, rolling back: %s", e)
             raise
         finally:
             await session.close()
@@ -155,7 +155,7 @@ async def check_async_database_health() -> bool:
             await db.execute(text("SELECT 1"))
         return True
     except Exception as e:
-        logger.error(f"Async database health check failed: {str(e)}")
+        logger.error("Async database health check failed: %s", e)
         return False
 
 

backend/app/core/demo_data.json

@@ -0,0 +1,366 @@
+{
+    "organizations": [
+        {
+            "name": "Acme Corp",
+            "slug": "acme-corp",
+            "description": "A leading provider of coyote-catching equipment."
+        },
+        {
+            "name": "Globex Corporation",
+            "slug": "globex",
+            "description": "We own the East Coast."
+        },
+        {
+            "name": "Soylent Corp",
+            "slug": "soylent",
+            "description": "Making food for the future."
+        },
+        {
+            "name": "Initech",
+            "slug": "initech",
+            "description": "Software for the soul."
+        },
+        {
+            "name": "Umbrella Corporation",
+            "slug": "umbrella",
+            "description": "Our business is life itself."
+        },
+        {
+            "name": "Massive Dynamic",
+            "slug": "massive-dynamic",
+            "description": "What don't we do?"
+        }
+    ],
+    "users": [
+        {
+            "email": "demo@example.com",
+            "password": "DemoPass1234!",
+            "first_name": "Demo",
+            "last_name": "User",
+            "is_superuser": false,
+            "organization_slug": "acme-corp",
+            "role": "member",
+            "is_active": true
+        },
+        {
+            "email": "alice@acme.com",
+            "password": "Demo123!",
+            "first_name": "Alice",
+            "last_name": "Smith",
+            "is_superuser": false,
+            "organization_slug": "acme-corp",
+            "role": "admin",
+            "is_active": true
+        },
+        {
+            "email": "bob@acme.com",
+            "password": "Demo123!",
+            "first_name": "Bob",
+            "last_name": "Jones",
+            "is_superuser": false,
+            "organization_slug": "acme-corp",
+            "role": "member",
+            "is_active": true
+        },
+        {
+            "email": "charlie@acme.com",
+            "password": "Demo123!",
+            "first_name": "Charlie",
+            "last_name": "Brown",
+            "is_superuser": false,
+            "organization_slug": "acme-corp",
+            "role": "member",
+            "is_active": false
+        },
+        {
+            "email": "diana@acme.com",
+            "password": "Demo123!",
+            "first_name": "Diana",
+            "last_name": "Prince",
+            "is_superuser": false,
+            "organization_slug": "acme-corp",
+            "role": "member",
+            "is_active": true
+        },
+        {
+            "email": "carol@globex.com",
+            "password": "Demo123!",
+            "first_name": "Carol",
+            "last_name": "Williams",
+            "is_superuser": false,
+            "organization_slug": "globex",
+            "role": "owner",
+            "is_active": true
+        },
+        {
+            "email": "dan@globex.com",
+            "password": "Demo123!",
+            "first_name": "Dan",
+            "last_name": "Miller",
+            "is_superuser": false,
+            "organization_slug": "globex",
+            "role": "member",
+            "is_active": true
+        },
+        {
+            "email": "ellen@globex.com",
+            "password": "Demo123!",
+            "first_name": "Ellen",
+            "last_name": "Ripley",
+            "is_superuser": false,
+            "organization_slug": "globex",
+            "role": "member",
+            "is_active": true
+        },
+        {
+            "email": "fred@globex.com",
+            "password": "Demo123!",
+            "first_name": "Fred",
+            "last_name": "Flintstone",
+            "is_superuser": false,
+            "organization_slug": "globex",
+            "role": "member",
+            "is_active": true
+        },
+        {
+            "email": "dave@soylent.com",
+            "password": "Demo123!",
+            "first_name": "Dave",
+            "last_name": "Brown",
+            "is_superuser": false,
+            "organization_slug": "soylent",
+            "role": "member",
+            "is_active": true
+        },
+        {
+            "email": "gina@soylent.com",
+            "password": "Demo123!",
+            "first_name": "Gina",
+            "last_name": "Torres",
+            "is_superuser": false,
+            "organization_slug": "soylent",
+            "role": "member",
+            "is_active": true
+        },
+        {
+            "email": "harry@soylent.com",
+            "password": "Demo123!",
+            "first_name": "Harry",
+            "last_name": "Potter",
+            "is_superuser": false,
+            "organization_slug": "soylent",
+            "role": "admin",
+            "is_active": true
+        },
+        {
+            "email": "eve@initech.com",
+            "password": "Demo123!",
+            "first_name": "Eve",
+            "last_name": "Davis",
+            "is_superuser": false,
+            "organization_slug": "initech",
+            "role": "admin",
+            "is_active": true
+        },
+        {
+            "email": "iris@initech.com",
+            "password": "Demo123!",
+            "first_name": "Iris",
+            "last_name": "West",
+            "is_superuser": false,
+            "organization_slug": "initech",
+            "role": "member",
+            "is_active": true
+        },
+        {
+            "email": "jack@initech.com",
+            "password": "Demo123!",
+            "first_name": "Jack",
+            "last_name": "Sparrow",
+            "is_superuser": false,
+            "organization_slug": "initech",
+            "role": "member",
+            "is_active": false
+        },
+        {
+            "email": "frank@umbrella.com",
+            "password": "Demo123!",
+            "first_name": "Frank",
+            "last_name": "Miller",
+            "is_superuser": false,
+            "organization_slug": "umbrella",
+            "role": "member",
+            "is_active": true
+        },
+        {
+            "email": "george@umbrella.com",
+            "password": "Demo123!",
+            "first_name": "George",
+            "last_name": "Costanza",
+            "is_superuser": false,
+            "organization_slug": "umbrella",
+            "role": "member",
+            "is_active": false
+        },
+        {
+            "email": "kate@umbrella.com",
+            "password": "Demo123!",
+            "first_name": "Kate",
+            "last_name": "Bishop",
+            "is_superuser": false,
+            "organization_slug": "umbrella",
+            "role": "member",
+            "is_active": true
+        },
+        {
+            "email": "leo@massive.com",
+            "password": "Demo123!",
+            "first_name": "Leo",
+            "last_name": "Messi",
+            "is_superuser": false,
+            "organization_slug": "massive-dynamic",
+            "role": "owner",
+            "is_active": true
+        },
+        {
+            "email": "mary@massive.com",
+            "password": "Demo123!",
+            "first_name": "Mary",
+            "last_name": "Jane",
+            "is_superuser": false,
+            "organization_slug": "massive-dynamic",
+            "role": "member",
+            "is_active": true
+        },
+        {
+            "email": "nathan@massive.com",
+            "password": "Demo123!",
+            "first_name": "Nathan",
+            "last_name": "Drake",
+            "is_superuser": false,
+            "organization_slug": "massive-dynamic",
+            "role": "member",
+            "is_active": true
+        },
+        {
+            "email": "olivia@massive.com",
+            "password": "Demo123!",
+            "first_name": "Olivia",
+            "last_name": "Dunham",
+            "is_superuser": false,
+            "organization_slug": "massive-dynamic",
+            "role": "admin",
+            "is_active": true
+        },
+        {
+            "email": "peter@massive.com",
+            "password": "Demo123!",
+            "first_name": "Peter",
+            "last_name": "Parker",
+            "is_superuser": false,
+            "organization_slug": "massive-dynamic",
+            "role": "member",
+            "is_active": true
+        },
+        {
+            "email": "quinn@massive.com",
+            "password": "Demo123!",
+            "first_name": "Quinn",
+            "last_name": "Mallory",
+            "is_superuser": false,
+            "organization_slug": "massive-dynamic",
+            "role": "member",
+            "is_active": true
+        },
+        {
+            "email": "grace@example.com",
+            "password": "Demo123!",
+            "first_name": "Grace",
+            "last_name": "Hopper",
+            "is_superuser": false,
+            "organization_slug": null,
+            "role": null,
+            "is_active": true
+        },
+        {
+            "email": "heidi@example.com",
+            "password": "Demo123!",
+            "first_name": "Heidi",
+            "last_name": "Klum",
+            "is_superuser": false,
+            "organization_slug": null,
+            "role": null,
+            "is_active": true
+        },
+        {
+            "email": "ivan@example.com",
+            "password": "Demo123!",
+            "first_name": "Ivan",
+            "last_name": "Drago",
+            "is_superuser": false,
+            "organization_slug": null,
+            "role": null,
+            "is_active": false
+        },
+        {
+            "email": "rachel@example.com",
+            "password": "Demo123!",
+            "first_name": "Rachel",
+            "last_name": "Green",
+            "is_superuser": false,
+            "organization_slug": null,
+            "role": null,
+            "is_active": true
+        },
+        {
+            "email": "sam@example.com",
+            "password": "Demo123!",
+            "first_name": "Sam",
+            "last_name": "Wilson",
+            "is_superuser": false,
+            "organization_slug": null,
+            "role": null,
+            "is_active": true
+        },
+        {
+            "email": "tony@example.com",
+            "password": "Demo123!",
+            "first_name": "Tony",
+            "last_name": "Stark",
+            "is_superuser": false,
+            "organization_slug": null,
+            "role": null,
+            "is_active": true
+        },
+        {
+            "email": "una@example.com",
+            "password": "Demo123!",
+            "first_name": "Una",
+            "last_name": "Chin-Riley",
+            "is_superuser": false,
+            "organization_slug": null,
+            "role": null,
+            "is_active": false
+        },
+        {
+            "email": "victor@example.com",
+            "password": "Demo123!",
+            "first_name": "Victor",
+            "last_name": "Von Doom",
+            "is_superuser": false,
+            "organization_slug": null,
+            "role": null,
+            "is_active": true
+        },
+        {
+            "email": "wanda@example.com",
+            "password": "Demo123!",
+            "first_name": "Wanda",
+            "last_name": "Maximoff",
+            "is_superuser": false,
+            "organization_slug": null,
+            "role": null,
+            "is_active": true
+        }
+    ]
+}

backend/app/core/exceptions.py

@@ -1,8 +1,8 @@
 """
 Custom exceptions and global exception handlers for the API.
 """
+
 import logging
-from typing import Optional, Union
 
 from fastapi import HTTPException, Request, status
 from fastapi.exceptions import RequestValidationError
@@ -27,17 +27,13 @@ class APIException(HTTPException):
         status_code: int,
         error_code: ErrorCode,
         message: str,
-        field: Optional[str] = None,
-        headers: Optional[dict] = None
+        field: str | None = None,
+        headers: dict | None = None,
     ):
         self.error_code = error_code
         self.field = field
         self.message = message
-        super().__init__(
-            status_code=status_code,
-            detail=message,
-            headers=headers
-        )
+        super().__init__(status_code=status_code, detail=message, headers=headers)
 
 
 class AuthenticationError(APIException):
@@ -47,14 +43,14 @@ class AuthenticationError(APIException):
         self,
         message: str = "Authentication failed",
         error_code: ErrorCode = ErrorCode.INVALID_CREDENTIALS,
-        field: Optional[str] = None
+        field: str | None = None,
     ):
         super().__init__(
             status_code=status.HTTP_401_UNAUTHORIZED,
             error_code=error_code,
             message=message,
             field=field,
-            headers={"WWW-Authenticate": "Bearer"}
+            headers={"WWW-Authenticate": "Bearer"},
         )
 
 
@@ -64,12 +60,12 @@ class AuthorizationError(APIException):
     def __init__(
         self,
         message: str = "Insufficient permissions",
-        error_code: ErrorCode = ErrorCode.INSUFFICIENT_PERMISSIONS
+        error_code: ErrorCode = ErrorCode.INSUFFICIENT_PERMISSIONS,
     ):
         super().__init__(
             status_code=status.HTTP_403_FORBIDDEN,
             error_code=error_code,
-            message=message
+            message=message,
         )
 
 
@@ -79,12 +75,12 @@ class NotFoundError(APIException):
     def __init__(
         self,
         message: str = "Resource not found",
-        error_code: ErrorCode = ErrorCode.NOT_FOUND
+        error_code: ErrorCode = ErrorCode.NOT_FOUND,
     ):
         super().__init__(
             status_code=status.HTTP_404_NOT_FOUND,
             error_code=error_code,
-            message=message
+            message=message,
         )
 
 
@@ -95,13 +91,13 @@ class DuplicateError(APIException):
         self,
         message: str = "Resource already exists",
         error_code: ErrorCode = ErrorCode.DUPLICATE_ENTRY,
-        field: Optional[str] = None
+        field: str | None = None,
     ):
         super().__init__(
             status_code=status.HTTP_409_CONFLICT,
             error_code=error_code,
             message=message,
-            field=field
+            field=field,
         )
 
 
@@ -112,13 +108,13 @@ class ValidationException(APIException):
         self,
         message: str = "Validation error",
         error_code: ErrorCode = ErrorCode.VALIDATION_ERROR,
-        field: Optional[str] = None
+        field: str | None = None,
     ):
         super().__init__(
             status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
             error_code=error_code,
             message=message,
-            field=field
+            field=field,
         )
 
 
@@ -128,12 +124,12 @@ class DatabaseError(APIException):
     def __init__(
         self,
         message: str = "Database operation failed",
-        error_code: ErrorCode = ErrorCode.DATABASE_ERROR
+        error_code: ErrorCode = ErrorCode.DATABASE_ERROR,
     ):
         super().__init__(
             status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
             error_code=error_code,
-            message=message
+            message=message,
         )
 
 
@@ -147,28 +143,26 @@ async def api_exception_handler(request: Request, exc: APIException) -> JSONResp
     Returns a standardized error response with error code and message.
     """
     logger.warning(
-        f"API exception: {exc.error_code} - {exc.message} "
-        f"(status: {exc.status_code}, path: {request.url.path})"
+        "API exception: %s - %s (status: %s, path: %s)",
+        exc.error_code,
+        exc.message,
+        exc.status_code,
+        request.url.path,
     )
 
     error_response = ErrorResponse(
-        errors=[ErrorDetail(
-            code=exc.error_code,
-            message=exc.message,
-            field=exc.field
-        )]
+        errors=[ErrorDetail(code=exc.error_code, message=exc.message, field=exc.field)]
     )
 
     return JSONResponse(
         status_code=exc.status_code,
         content=error_response.model_dump(),
-        headers=exc.headers
+        headers=exc.headers,
     )
 
 
 async def validation_exception_handler(
-    request: Request,
-    exc: Union[RequestValidationError, ValidationError]
+    request: Request, exc: RequestValidationError | ValidationError
 ) -> JSONResponse:
     """
     Handler for Pydantic validation errors.
@@ -189,22 +183,21 @@ async def validation_exception_handler(
             # Skip 'body' or 'query' prefix in location
             field = ".".join(str(x) for x in error["loc"][1:])
 
-        errors.append(ErrorDetail(
-            code=ErrorCode.VALIDATION_ERROR,
-            message=error["msg"],
-            field=field
-        ))
+        errors.append(
+            ErrorDetail(
+                code=ErrorCode.VALIDATION_ERROR, message=error["msg"], field=field
+            )
+        )
 
     logger.warning(
-        f"Validation error: {len(errors)} errors "
-        f"(path: {request.url.path})"
+        "Validation error: %s errors (path: %s)", len(errors), request.url.path
     )
 
     error_response = ErrorResponse(errors=errors)
 
     return JSONResponse(
         status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
-        content=error_response.model_dump()
+        content=error_response.model_dump(),
     )
 
 
@@ -226,26 +219,24 @@ async def http_exception_handler(request: Request, exc: HTTPException) -> JSONRe
     }
 
     error_code = status_code_to_error_code.get(
-        exc.status_code,
-        ErrorCode.INTERNAL_ERROR
+        exc.status_code, ErrorCode.INTERNAL_ERROR
     )
 
     logger.warning(
-        f"HTTP exception: {exc.status_code} - {exc.detail} "
-        f"(path: {request.url.path})"
+        "HTTP exception: %s - %s (path: %s)",
+        exc.status_code,
+        exc.detail,
+        request.url.path,
     )
 
     error_response = ErrorResponse(
-        errors=[ErrorDetail(
-            code=error_code,
-            message=str(exc.detail)
-        )]
+        errors=[ErrorDetail(code=error_code, message=str(exc.detail), field=None)]
     )
 
     return JSONResponse(
         status_code=exc.status_code,
         content=error_response.model_dump(),
-        headers=exc.headers
+        headers=exc.headers,
     )
 
 
@@ -256,27 +247,26 @@ async def unhandled_exception_handler(request: Request, exc: Exception) -> JSONR
     Logs the full exception and returns a generic error response to avoid
     leaking sensitive information in production.
     """
-    logger.error(
-        f"Unhandled exception: {type(exc).__name__} - {str(exc)} "
-        f"(path: {request.url.path})",
-        exc_info=True
+    logger.exception(
+        "Unhandled exception: %s - %s (path: %s)",
+        type(exc).__name__,
+        exc,
+        request.url.path,
     )
 
     # In production, don't expose internal error details
     from app.core.config import settings
+
     if settings.ENVIRONMENT == "production":
         message = "An internal error occurred. Please try again later."
     else:
-        message = f"{type(exc).__name__}: {str(exc)}"
+        message = f"{type(exc).__name__}: {exc!s}"
 
     error_response = ErrorResponse(
-        errors=[ErrorDetail(
-            code=ErrorCode.INTERNAL_ERROR,
-            message=message
-        )]
+        errors=[ErrorDetail(code=ErrorCode.INTERNAL_ERROR, message=message, field=None)]
     )
 
     return JSONResponse(
         status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
-        content=error_response.model_dump()
+        content=error_response.model_dump(),
     )

backend/app/core/repository_exceptions.py

@@ -0,0 +1,26 @@
+"""
+Custom exceptions for the repository layer.
+
+These exceptions allow services and routes to handle database-level errors
+with proper semantics, without leaking SQLAlchemy internals.
+"""
+
+
+class RepositoryError(Exception):
+    """Base for all repository-layer errors."""
+
+
+class DuplicateEntryError(RepositoryError):
+    """Raised on unique constraint violations. Maps to HTTP 409 Conflict."""
+
+
+class IntegrityConstraintError(RepositoryError):
+    """Raised on FK or check constraint violations."""
+
+
+class RecordNotFoundError(RepositoryError):
+    """Raised when an expected record doesn't exist."""
+
+
+class InvalidInputError(RepositoryError):
+    """Raised on bad pagination params, invalid UUIDs, or other invalid inputs."""

backend/app/crud/__init__.py

@@ -1,6 +0,0 @@
-# app/crud/__init__.py
-from .organization import organization
-from .session import session as session_crud
-from .user import user
-
-__all__ = ["user", "session_crud", "organization"]

backend/app/crud/session.py

@@ -1,478 +0,0 @@
-"""
-Async CRUD operations for user sessions using SQLAlchemy 2.0 patterns.
-"""
-import logging
-import uuid
-from datetime import datetime, timezone, timedelta
-from typing import List, Optional
-from uuid import UUID
-
-from sqlalchemy import and_, select, update, delete, func
-from sqlalchemy.ext.asyncio import AsyncSession
-from sqlalchemy.orm import joinedload
-
-from app.crud.base import CRUDBase
-from app.models.user_session import UserSession
-from app.schemas.sessions import SessionCreate, SessionUpdate
-
-logger = logging.getLogger(__name__)
-
-
-class CRUDSession(CRUDBase[UserSession, SessionCreate, SessionUpdate]):
-    """Async CRUD operations for user sessions."""
-
-    async def get_by_jti(self, db: AsyncSession, *, jti: str) -> Optional[UserSession]:
-        """
-        Get session by refresh token JTI.
-
-        Args:
-            db: Database session
-            jti: Refresh token JWT ID
-
-        Returns:
-            UserSession if found, None otherwise
-        """
-        try:
-            result = await db.execute(
-                select(UserSession).where(UserSession.refresh_token_jti == jti)
-            )
-            return result.scalar_one_or_none()
-        except Exception as e:
-            logger.error(f"Error getting session by JTI {jti}: {str(e)}")
-            raise
-
-    async def get_active_by_jti(self, db: AsyncSession, *, jti: str) -> Optional[UserSession]:
-        """
-        Get active session by refresh token JTI.
-
-        Args:
-            db: Database session
-            jti: Refresh token JWT ID
-
-        Returns:
-            Active UserSession if found, None otherwise
-        """
-        try:
-            result = await db.execute(
-                select(UserSession).where(
-                    and_(
-                        UserSession.refresh_token_jti == jti,
-                        UserSession.is_active == True
-                    )
-                )
-            )
-            return result.scalar_one_or_none()
-        except Exception as e:
-            logger.error(f"Error getting active session by JTI {jti}: {str(e)}")
-            raise
-
-    async def get_user_sessions(
-        self,
-        db: AsyncSession,
-        *,
-        user_id: str,
-        active_only: bool = True,
-        with_user: bool = False
-    ) -> List[UserSession]:
-        """
-        Get all sessions for a user with optional eager loading.
-
-        Args:
-            db: Database session
-            user_id: User ID
-            active_only: If True, return only active sessions
-            with_user: If True, eager load user relationship to prevent N+1
-
-        Returns:
-            List of UserSession objects
-        """
-        try:
-            # Convert user_id string to UUID if needed
-            user_uuid = UUID(user_id) if isinstance(user_id, str) else user_id
-
-            query = select(UserSession).where(UserSession.user_id == user_uuid)
-
-            # Add eager loading if requested to prevent N+1 queries
-            if with_user:
-                query = query.options(joinedload(UserSession.user))
-
-            if active_only:
-                query = query.where(UserSession.is_active == True)
-
-            query = query.order_by(UserSession.last_used_at.desc())
-            result = await db.execute(query)
-            return list(result.scalars().all())
-        except Exception as e:
-            logger.error(f"Error getting sessions for user {user_id}: {str(e)}")
-            raise
-
-    async def create_session(
-        self,
-        db: AsyncSession,
-        *,
-        obj_in: SessionCreate
-    ) -> UserSession:
-        """
-        Create a new user session.
-
-        Args:
-            db: Database session
-            obj_in: SessionCreate schema with session data
-
-        Returns:
-            Created UserSession
-
-        Raises:
-            ValueError: If session creation fails
-        """
-        try:
-            db_obj = UserSession(
-                user_id=obj_in.user_id,
-                refresh_token_jti=obj_in.refresh_token_jti,
-                device_name=obj_in.device_name,
-                device_id=obj_in.device_id,
-                ip_address=obj_in.ip_address,
-                user_agent=obj_in.user_agent,
-                last_used_at=obj_in.last_used_at,
-                expires_at=obj_in.expires_at,
-                is_active=True,
-                location_city=obj_in.location_city,
-                location_country=obj_in.location_country,
-            )
-            db.add(db_obj)
-            await db.commit()
-            await db.refresh(db_obj)
-
-            logger.info(
-                f"Session created for user {obj_in.user_id} from {obj_in.device_name} "
-                f"(IP: {obj_in.ip_address})"
-            )
-
-            return db_obj
-        except Exception as e:
-            await db.rollback()
-            logger.error(f"Error creating session: {str(e)}", exc_info=True)
-            raise ValueError(f"Failed to create session: {str(e)}")
-
-    async def deactivate(self, db: AsyncSession, *, session_id: str) -> Optional[UserSession]:
-        """
-        Deactivate a session (logout from device).
-
-        Args:
-            db: Database session
-            session_id: Session UUID
-
-        Returns:
-            Deactivated UserSession if found, None otherwise
-        """
-        try:
-            session = await self.get(db, id=session_id)
-            if not session:
-                logger.warning(f"Session {session_id} not found for deactivation")
-                return None
-
-            session.is_active = False
-            db.add(session)
-            await db.commit()
-            await db.refresh(session)
-
-            logger.info(
-                f"Session {session_id} deactivated for user {session.user_id} "
-                f"({session.device_name})"
-            )
-
-            return session
-        except Exception as e:
-            await db.rollback()
-            logger.error(f"Error deactivating session {session_id}: {str(e)}")
-            raise
-
-    async def deactivate_all_user_sessions(
-        self,
-        db: AsyncSession,
-        *,
-        user_id: str
-    ) -> int:
-        """
-        Deactivate all active sessions for a user (logout from all devices).
-
-        Args:
-            db: Database session
-            user_id: User ID
-
-        Returns:
-            Number of sessions deactivated
-        """
-        try:
-            # Convert user_id string to UUID if needed
-            user_uuid = UUID(user_id) if isinstance(user_id, str) else user_id
-
-            stmt = (
-                update(UserSession)
-                .where(
-                    and_(
-                        UserSession.user_id == user_uuid,
-                        UserSession.is_active == True
-                    )
-                )
-                .values(is_active=False)
-            )
-
-            result = await db.execute(stmt)
-            await db.commit()
-
-            count = result.rowcount
-
-            logger.info(f"Deactivated {count} sessions for user {user_id}")
-
-            return count
-        except Exception as e:
-            await db.rollback()
-            logger.error(f"Error deactivating all sessions for user {user_id}: {str(e)}")
-            raise
-
-    async def update_last_used(
-        self,
-        db: AsyncSession,
-        *,
-        session: UserSession
-    ) -> UserSession:
-        """
-        Update the last_used_at timestamp for a session.
-
-        Args:
-            db: Database session
-            session: UserSession object
-
-        Returns:
-            Updated UserSession
-        """
-        try:
-            session.last_used_at = datetime.now(timezone.utc)
-            db.add(session)
-            await db.commit()
-            await db.refresh(session)
-            return session
-        except Exception as e:
-            await db.rollback()
-            logger.error(f"Error updating last_used for session {session.id}: {str(e)}")
-            raise
-
-    async def update_refresh_token(
-        self,
-        db: AsyncSession,
-        *,
-        session: UserSession,
-        new_jti: str,
-        new_expires_at: datetime
-    ) -> UserSession:
-        """
-        Update session with new refresh token JTI and expiration.
-
-        Called during token refresh.
-
-        Args:
-            db: Database session
-            session: UserSession object
-            new_jti: New refresh token JTI
-            new_expires_at: New expiration datetime
-
-        Returns:
-            Updated UserSession
-        """
-        try:
-            session.refresh_token_jti = new_jti
-            session.expires_at = new_expires_at
-            session.last_used_at = datetime.now(timezone.utc)
-            db.add(session)
-            await db.commit()
-            await db.refresh(session)
-            return session
-        except Exception as e:
-            await db.rollback()
-            logger.error(f"Error updating refresh token for session {session.id}: {str(e)}")
-            raise
-
-    async def cleanup_expired(self, db: AsyncSession, *, keep_days: int = 30) -> int:
-        """
-        Clean up expired sessions using optimized bulk DELETE.
-
-        Deletes sessions that are:
-        - Expired AND inactive
-        - Older than keep_days
-
-        Uses single DELETE query instead of N individual deletes for efficiency.
-
-        Args:
-            db: Database session
-            keep_days: Keep inactive sessions for this many days (for audit)
-
-        Returns:
-            Number of sessions deleted
-        """
-        try:
-            cutoff_date = datetime.now(timezone.utc) - timedelta(days=keep_days)
-            now = datetime.now(timezone.utc)
-
-            # Use bulk DELETE with WHERE clause - single query
-            stmt = delete(UserSession).where(
-                and_(
-                    UserSession.is_active == False,
-                    UserSession.expires_at < now,
-                    UserSession.created_at < cutoff_date
-                )
-            )
-
-            result = await db.execute(stmt)
-            await db.commit()
-
-            count = result.rowcount
-
-            if count > 0:
-                logger.info(f"Cleaned up {count} expired sessions using bulk DELETE")
-
-            return count
-        except Exception as e:
-            await db.rollback()
-            logger.error(f"Error cleaning up expired sessions: {str(e)}")
-            raise
-
-    async def cleanup_expired_for_user(
-        self,
-        db: AsyncSession,
-        *,
-        user_id: str
-    ) -> int:
-        """
-        Clean up expired and inactive sessions for a specific user.
-
-        Uses single bulk DELETE query for efficiency instead of N individual deletes.
-
-        Args:
-            db: Database session
-            user_id: User ID to cleanup sessions for
-
-        Returns:
-            Number of sessions deleted
-        """
-        try:
-            # Validate UUID
-            try:
-                uuid_obj = uuid.UUID(user_id)
-            except (ValueError, AttributeError):
-                logger.error(f"Invalid UUID format: {user_id}")
-                raise ValueError(f"Invalid user ID format: {user_id}")
-
-            now = datetime.now(timezone.utc)
-
-            # Use bulk DELETE with WHERE clause - single query
-            stmt = delete(UserSession).where(
-                and_(
-                    UserSession.user_id == uuid_obj,
-                    UserSession.is_active == False,
-                    UserSession.expires_at < now
-                )
-            )
-
-            result = await db.execute(stmt)
-            await db.commit()
-
-            count = result.rowcount
-
-            if count > 0:
-                logger.info(
-                    f"Cleaned up {count} expired sessions for user {user_id} using bulk DELETE"
-                )
-
-            return count
-        except Exception as e:
-            await db.rollback()
-            logger.error(
-                f"Error cleaning up expired sessions for user {user_id}: {str(e)}"
-            )
-            raise
-
-    async def get_user_session_count(self, db: AsyncSession, *, user_id: str) -> int:
-        """
-        Get count of active sessions for a user.
-
-        Args:
-            db: Database session
-            user_id: User ID
-
-        Returns:
-            Number of active sessions
-        """
-        try:
-            # Convert user_id string to UUID if needed
-            user_uuid = UUID(user_id) if isinstance(user_id, str) else user_id
-
-            result = await db.execute(
-                select(func.count(UserSession.id)).where(
-                    and_(
-                        UserSession.user_id == user_uuid,
-                        UserSession.is_active == True
-                    )
-                )
-            )
-            return result.scalar_one()
-        except Exception as e:
-            logger.error(f"Error counting sessions for user {user_id}: {str(e)}")
-            raise
-
-    async def get_all_sessions(
-        self,
-        db: AsyncSession,
-        *,
-        skip: int = 0,
-        limit: int = 100,
-        active_only: bool = True,
-        with_user: bool = True
-    ) -> tuple[List[UserSession], int]:
-        """
-        Get all sessions across all users with pagination (admin only).
-
-        Args:
-            db: Database session
-            skip: Number of records to skip
-            limit: Maximum number of records to return
-            active_only: If True, return only active sessions
-            with_user: If True, eager load user relationship to prevent N+1
-
-        Returns:
-            Tuple of (list of UserSession objects, total count)
-        """
-        try:
-            # Build query
-            query = select(UserSession)
-
-            # Add eager loading if requested to prevent N+1 queries
-            if with_user:
-                query = query.options(joinedload(UserSession.user))
-
-            if active_only:
-                query = query.where(UserSession.is_active == True)
-
-            # Get total count
-            count_query = select(func.count(UserSession.id))
-            if active_only:
-                count_query = count_query.where(UserSession.is_active == True)
-
-            count_result = await db.execute(count_query)
-            total = count_result.scalar_one()
-
-            # Apply pagination and ordering
-            query = query.order_by(UserSession.last_used_at.desc()).offset(skip).limit(limit)
-
-            result = await db.execute(query)
-            sessions = list(result.scalars().all())
-
-            return sessions, total
-
-        except Exception as e:
-            logger.error(f"Error getting all sessions: {str(e)}", exc_info=True)
-            raise
-
-
-# Create singleton instance
-session = CRUDSession(UserSession)

backend/app/init_db.py

@@ -4,20 +4,28 @@ Async database initialization script.
 
 Creates the first superuser if configured and doesn't already exist.
 """
+
 import asyncio
+import json
 import logging
-from typing import Optional
+import random
+from datetime import UTC, datetime, timedelta
+from pathlib import Path
+
+from sqlalchemy import select, text
 
 from app.core.config import settings
 from app.core.database import SessionLocal, engine
-from app.crud.user import user as user_crud
+from app.models.organization import Organization
 from app.models.user import User
+from app.models.user_organization import UserOrganization
+from app.repositories.user import user_repo as user_repo
 from app.schemas.users import UserCreate
 
 logger = logging.getLogger(__name__)
 
 
-async def init_db() -> Optional[User]:
+async def init_db() -> User | None:
     """
     Initialize database with first superuser if settings are configured and user doesn't exist.
 
@@ -26,21 +34,27 @@ async def init_db() -> Optional[User]:
     """
     # Use default values if not set in environment variables
     superuser_email = settings.FIRST_SUPERUSER_EMAIL or "admin@example.com"
-    superuser_password = settings.FIRST_SUPERUSER_PASSWORD or "AdminPassword123!"
+
+    default_password = "AdminPassword123!"
+    if settings.DEMO_MODE:
+        default_password = "AdminPass1234!"
+
+    superuser_password = settings.FIRST_SUPERUSER_PASSWORD or default_password
 
     if not settings.FIRST_SUPERUSER_EMAIL or not settings.FIRST_SUPERUSER_PASSWORD:
         logger.warning(
             "First superuser credentials not configured in settings. "
-            f"Using defaults: {superuser_email}"
+            "Using defaults: %s",
+            superuser_email,
         )
 
     async with SessionLocal() as session:
         try:
             # Check if superuser already exists
-            existing_user = await user_crud.get_by_email(session, email=superuser_email)
+            existing_user = await user_repo.get_by_email(session, email=superuser_email)
 
             if existing_user:
-                logger.info(f"Superuser already exists: {existing_user.email}")
+                logger.info("Superuser already exists: %s", existing_user.email)
                 return existing_user
 
             # Create superuser if doesn't exist
@@ -49,34 +63,158 @@ async def init_db() -> Optional[User]:
                 password=superuser_password,
                 first_name="Admin",
                 last_name="User",
-                is_superuser=True
+                is_superuser=True,
             )
 
-            user = await user_crud.create(session, obj_in=user_in)
+            user = await user_repo.create(session, obj_in=user_in)
             await session.commit()
             await session.refresh(user)
 
-            logger.info(f"Created first superuser: {user.email}")
+            logger.info("Created first superuser: %s", user.email)
+
+            # Create demo data if in demo mode
+            if settings.DEMO_MODE:
+                await load_demo_data(session)
+
             return user
 
         except Exception as e:
             await session.rollback()
-            logger.error(f"Error initializing database: {e}")
+            logger.error("Error initializing database: %s", e)
             raise
 
 
+def _load_json_file(path: Path):
+    with open(path) as f:
+        return json.load(f)
+
+
+async def load_demo_data(session):
+    """Load demo data from JSON file."""
+    demo_data_path = Path(__file__).parent / "core" / "demo_data.json"
+    if not demo_data_path.exists():
+        logger.warning("Demo data file not found: %s", demo_data_path)
+        return
+
+    try:
+        # Use asyncio.to_thread to avoid blocking the event loop
+        data = await asyncio.to_thread(_load_json_file, demo_data_path)
+
+        # Create Organizations
+        org_map = {}
+        for org_data in data.get("organizations", []):
+            # Check if org exists
+            result = await session.execute(
+                text("SELECT * FROM organizations WHERE slug = :slug"),
+                {"slug": org_data["slug"]},
+            )
+            existing_org = result.first()
+
+            if not existing_org:
+                org = Organization(
+                    name=org_data["name"],
+                    slug=org_data["slug"],
+                    description=org_data.get("description"),
+                    is_active=True,
+                )
+                session.add(org)
+                await session.flush()  # Flush to get ID
+                org_map[org.slug] = org
+                logger.info("Created demo organization: %s", org.name)
+            else:
+                # We can't easily get the ORM object from raw SQL result for map without querying again or mapping
+                # So let's just query it properly if we need it for relationships
+                # But for simplicity in this script, let's just assume we created it or it exists.
+                # To properly map for users, we need the ID.
+                # Let's use a simpler approach: just try to create, if slug conflict, skip.
+                pass
+
+        # Re-query all orgs to build map for users
+        result = await session.execute(select(Organization))
+        orgs = result.scalars().all()
+        org_map = {org.slug: org for org in orgs}
+
+        # Create Users
+        for user_data in data.get("users", []):
+            existing_user = await user_repo.get_by_email(
+                session, email=user_data["email"]
+            )
+            if not existing_user:
+                # Create user
+                user_in = UserCreate(
+                    email=user_data["email"],
+                    password=user_data["password"],
+                    first_name=user_data["first_name"],
+                    last_name=user_data["last_name"],
+                    is_superuser=user_data["is_superuser"],
+                    is_active=user_data.get("is_active", True),
+                )
+                user = await user_repo.create(session, obj_in=user_in)
+
+                # Randomize created_at for demo data (last 30 days)
+                # This makes the charts look more realistic
+                days_ago = random.randint(0, 30)  # noqa: S311
+                random_time = datetime.now(UTC) - timedelta(days=days_ago)
+                # Add some random hours/minutes variation
+                random_time = random_time.replace(
+                    hour=random.randint(0, 23),  # noqa: S311
+                    minute=random.randint(0, 59),  # noqa: S311
+                )
+
+                # Update the timestamp and is_active directly in the database
+                # We do this to ensure the values are persisted correctly
+                await session.execute(
+                    text(
+                        "UPDATE users SET created_at = :created_at, is_active = :is_active WHERE id = :user_id"
+                    ),
+                    {
+                        "created_at": random_time,
+                        "is_active": user_data.get("is_active", True),
+                        "user_id": user.id,
+                    },
+                )
+
+                logger.info(
+                    "Created demo user: %s (created %s days ago, active=%s)",
+                    user.email,
+                    days_ago,
+                    user_data.get("is_active", True),
+                )
+
+                # Add to organization if specified
+                org_slug = user_data.get("organization_slug")
+                role = user_data.get("role")
+                if org_slug and org_slug in org_map and role:
+                    org = org_map[org_slug]
+                    # Check if membership exists (it shouldn't for new user)
+                    member = UserOrganization(
+                        user_id=user.id, organization_id=org.id, role=role
+                    )
+                    session.add(member)
+                    logger.info("Added %s to %s as %s", user.email, org.name, role)
+            else:
+                logger.info("Demo user already exists: %s", existing_user.email)
+
+        await session.commit()
+        logger.info("Demo data loaded successfully")
+
+    except Exception as e:
+        logger.error("Error loading demo data: %s", e)
+        raise
+
+
 async def main():
     """Main entry point for database initialization."""
     # Configure logging to show info logs
     logging.basicConfig(
         level=logging.INFO,
-        format="%(asctime)s - %(name)s - %(levelname)s - %(message)s"
+        format="%(asctime)s - %(name)s - %(levelname)s - %(message)s",
     )
 
     try:
         user = await init_db()
         if user:
-            print(f"✓ Database initialized successfully")
+            print("✓ Database initialized successfully")
             print(f"✓ Superuser: {user.email}")
         else:
             print("✗ Failed to initialize database")

backend/app/main.py

@@ -1,11 +1,11 @@
 import logging
 import os
 from contextlib import asynccontextmanager
-from datetime import datetime
-from typing import Dict, Any
+from datetime import UTC, datetime
+from typing import Any
 
 from apscheduler.schedulers.asyncio import AsyncIOScheduler
-from fastapi import FastAPI, status, Request, HTTPException
+from fastapi import FastAPI, HTTPException, Request, status
 from fastapi.exceptions import RequestValidationError
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import HTMLResponse, JSONResponse
@@ -14,14 +14,15 @@ from slowapi.errors import RateLimitExceeded
 from slowapi.util import get_remote_address
 
 from app.api.main import api_router
+from app.api.routes.oauth_provider import wellknown_router as oauth_wellknown_router
 from app.core.config import settings
-from app.core.database import check_database_health
+from app.core.database import check_database_health, close_async_db
 from app.core.exceptions import (
     APIException,
     api_exception_handler,
-    validation_exception_handler,
     http_exception_handler,
-    unhandled_exception_handler
+    unhandled_exception_handler,
+    validation_exception_handler,
 )
 
 scheduler = AsyncIOScheduler()
@@ -52,11 +53,11 @@ async def lifespan(app: FastAPI):
         # Runs daily at 2:00 AM server time
         scheduler.add_job(
             cleanup_expired_sessions,
-            'cron',
+            "cron",
             hour=2,
             minute=0,
-            id='cleanup_expired_sessions',
-            replace_existing=True
+            id="cleanup_expired_sessions",
+            replace_existing=True,
         )
 
         scheduler.start()
@@ -71,14 +72,15 @@ async def lifespan(app: FastAPI):
     if os.getenv("IS_TEST", "False") != "True":
         scheduler.shutdown()
         logger.info("Scheduled jobs stopped")
+    await close_async_db()
 
 
-logger.info(f"Starting app!!!")
+logger.info("Starting app!!!")
 app = FastAPI(
     title=settings.PROJECT_NAME,
     version=settings.VERSION,
     openapi_url=f"{settings.API_V1_STR}/openapi.json",
-    lifespan=lifespan
+    lifespan=lifespan,
 )
 
 # Add rate limiter state to app
@@ -96,7 +98,14 @@ app.add_middleware(
     CORSMiddleware,
     allow_origins=settings.BACKEND_CORS_ORIGINS,
     allow_credentials=True,
-    allow_methods=["GET", "POST", "PUT", "PATCH", "DELETE", "OPTIONS"],  # Explicit methods only
+    allow_methods=[
+        "GET",
+        "POST",
+        "PUT",
+        "PATCH",
+        "DELETE",
+        "OPTIONS",
+    ],  # Explicit methods only
     allow_headers=[
         "Content-Type",
         "Authorization",
@@ -129,12 +138,14 @@ async def limit_request_size(request: Request, call_next):
             status_code=status.HTTP_413_REQUEST_ENTITY_TOO_LARGE,
             content={
                 "success": False,
-                "errors": [{
-                    "code": "REQUEST_TOO_LARGE",
-                    "message": f"Request body too large. Maximum size is {MAX_REQUEST_SIZE // (1024 * 1024)}MB",
-                    "field": None
-                }]
-            }
+                "errors": [
+                    {
+                        "code": "REQUEST_TOO_LARGE",
+                        "message": f"Request body too large. Maximum size is {MAX_REQUEST_SIZE // (1024 * 1024)}MB",
+                        "field": None,
+                    }
+                ],
+            },
         )
 
     response = await call_next(request)
@@ -165,15 +176,19 @@ async def add_security_headers(request: Request, call_next):
 
     # Enforce HTTPS in production
     if settings.ENVIRONMENT == "production":
-        response.headers["Strict-Transport-Security"] = "max-age=31536000; includeSubDomains"
+        response.headers["Strict-Transport-Security"] = (
+            "max-age=31536000; includeSubDomains"
+        )
 
     # Content Security Policy
     csp_mode = settings.CSP_MODE.lower()
 
     # Special handling for API docs
-    is_docs = request.url.path in ["/docs", "/redoc"] or \
-              request.url.path.startswith("/docs/") or \
-              request.url.path.startswith("/redoc/")
+    is_docs = (
+        request.url.path in ["/docs", "/redoc"]
+        or request.url.path.startswith("/docs/")
+        or request.url.path.startswith("/redoc/")
+    )
 
     if csp_mode == "disabled":
         # No CSP (only for local development/debugging)
@@ -264,7 +279,7 @@ async def root():
     description="Check the health status of the API and its dependencies",
     response_description="Health status information",
     tags=["Health"],
-    operation_id="health_check"
+    operation_id="health_check",
 )
 async def health_check() -> JSONResponse:
     """
@@ -278,12 +293,12 @@ async def health_check() -> JSONResponse:
             - environment: Current environment (development, staging, production)
             - database: Database connectivity status
     """
-    health_status: Dict[str, Any] = {
+    health_status: dict[str, Any] = {
         "status": "healthy",
-        "timestamp": datetime.utcnow().isoformat() + "Z",
+        "timestamp": datetime.now(UTC).isoformat().replace("+00:00", "Z"),
         "version": settings.VERSION,
         "environment": settings.ENVIRONMENT,
-        "checks": {}
+        "checks": {},
     }
 
     response_status = status.HTTP_200_OK
@@ -294,7 +309,7 @@ async def health_check() -> JSONResponse:
         if db_healthy:
             health_status["checks"]["database"] = {
                 "status": "healthy",
-                "message": "Database connection successful"
+                "message": "Database connection successful",
             }
         else:
             raise Exception("Database health check returned unhealthy status")
@@ -302,15 +317,16 @@ async def health_check() -> JSONResponse:
         health_status["status"] = "unhealthy"
         health_status["checks"]["database"] = {
             "status": "unhealthy",
-            "message": f"Database connection failed: {str(e)}"
+            "message": f"Database connection failed: {e!s}",
         }
         response_status = status.HTTP_503_SERVICE_UNAVAILABLE
-        logger.error(f"Health check failed - database error: {e}")
+        logger.error("Health check failed - database error: %s", e)
 
-    return JSONResponse(
-        status_code=response_status,
-        content=health_status
-    )
+    return JSONResponse(status_code=response_status, content=health_status)
 
 
 app.include_router(api_router, prefix=settings.API_V1_STR)
+
+# OAuth 2.0 well-known endpoint at root level per RFC 8414
+# This allows MCP clients to discover the OAuth server metadata at /.well-known/oauth-authorization-server
+app.include_router(oauth_wellknown_router)

backend/app/models/__init__.py

@@ -2,17 +2,40 @@
 Models package initialization.
 Imports all models to ensure they're registered with SQLAlchemy.
 """
+
 # First import Base to avoid circular imports
 from app.core.database import Base
+
 from .base import TimestampMixin, UUIDMixin
+
+# OAuth models (client mode - authenticate via Google/GitHub)
+from .oauth_account import OAuthAccount
+
+# OAuth provider models (server mode - act as authorization server for MCP)
+from .oauth_authorization_code import OAuthAuthorizationCode
+from .oauth_client import OAuthClient
+from .oauth_provider_token import OAuthConsent, OAuthProviderRefreshToken
+from .oauth_state import OAuthState
 from .organization import Organization
+
 # Import models
 from .user import User
-from .user_organization import UserOrganization, OrganizationRole
+from .user_organization import OrganizationRole, UserOrganization
 from .user_session import UserSession
 
 __all__ = [
-    'Base', 'TimestampMixin', 'UUIDMixin',
-    'User', 'UserSession',
-    'Organization', 'UserOrganization', 'OrganizationRole',
-]
+    "Base",
+    "OAuthAccount",
+    "OAuthAuthorizationCode",
+    "OAuthClient",
+    "OAuthConsent",
+    "OAuthProviderRefreshToken",
+    "OAuthState",
+    "Organization",
+    "OrganizationRole",
+    "TimestampMixin",
+    "UUIDMixin",
+    "User",
+    "UserOrganization",
+    "UserSession",
+]

backend/app/models/base.py

@@ -1,20 +1,28 @@
 import uuid
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 
 from sqlalchemy import Column, DateTime
 from sqlalchemy.dialects.postgresql import UUID
 
 # noinspection PyUnresolvedReferences
-from app.core.database import Base
+from app.core.database import Base  # Re-exported for other models
 
 
 class TimestampMixin:
     """Mixin to add created_at and updated_at timestamps to models"""
-    created_at = Column(DateTime(timezone=True), default=lambda: datetime.now(timezone.utc), nullable=False)
-    updated_at = Column(DateTime(timezone=True), default=lambda: datetime.now(timezone.utc),
-                        onupdate=lambda: datetime.now(timezone.utc), nullable=False)
+
+    created_at = Column(
+        DateTime(timezone=True), default=lambda: datetime.now(UTC), nullable=False
+    )
+    updated_at = Column(
+        DateTime(timezone=True),
+        default=lambda: datetime.now(UTC),
+        onupdate=lambda: datetime.now(UTC),
+        nullable=False,
+    )
 
 
 class UUIDMixin:
     """Mixin to add UUID primary keys to models"""
+
     id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)

backend/app/models/oauth_account.py

@@ -0,0 +1,55 @@
+"""OAuth account model for linking external OAuth providers to users."""
+
+from sqlalchemy import Column, DateTime, ForeignKey, Index, String, UniqueConstraint
+from sqlalchemy.dialects.postgresql import UUID
+from sqlalchemy.orm import relationship
+
+from .base import Base, TimestampMixin, UUIDMixin
+
+
+class OAuthAccount(Base, UUIDMixin, TimestampMixin):
+    """
+    Links OAuth provider accounts to users.
+
+    Supports multiple OAuth providers per user (e.g., user can have both
+    Google and GitHub connected). Each provider account is uniquely identified
+    by (provider, provider_user_id).
+    """
+
+    __tablename__ = "oauth_accounts"
+
+    # Link to user
+    user_id = Column(
+        UUID(as_uuid=True),
+        ForeignKey("users.id", ondelete="CASCADE"),
+        nullable=False,
+        index=True,
+    )
+
+    # OAuth provider identification
+    provider = Column(
+        String(50), nullable=False, index=True
+    )  # google, github, microsoft
+    provider_user_id = Column(String(255), nullable=False)  # Provider's unique user ID
+    provider_email = Column(
+        String(255), nullable=True, index=True
+    )  # Email from provider (for reference)
+
+    # Optional: store provider tokens for API access
+    # TODO: Encrypt these at rest in production (requires key management infrastructure)
+    access_token = Column(String(2048), nullable=True)
+    refresh_token = Column(String(2048), nullable=True)
+    token_expires_at = Column(DateTime(timezone=True), nullable=True)
+
+    # Relationship
+    user = relationship("User", back_populates="oauth_accounts")
+
+    __table_args__ = (
+        # Each provider account can only be linked to one user
+        UniqueConstraint("provider", "provider_user_id", name="uq_oauth_provider_user"),
+        # Index for finding all OAuth accounts for a user + provider
+        Index("ix_oauth_accounts_user_provider", "user_id", "provider"),
+    )
+
+    def __repr__(self):
+        return f"<OAuthAccount {self.provider}:{self.provider_user_id}>"

backend/app/models/oauth_authorization_code.py

@@ -0,0 +1,100 @@
+"""OAuth authorization code model for OAuth provider mode."""
+
+from datetime import UTC, datetime
+
+from sqlalchemy import Boolean, Column, DateTime, ForeignKey, Index, String
+from sqlalchemy.dialects.postgresql import UUID
+from sqlalchemy.orm import relationship
+
+from .base import Base, TimestampMixin, UUIDMixin
+
+
+class OAuthAuthorizationCode(Base, UUIDMixin, TimestampMixin):
+    """
+    OAuth 2.0 Authorization Code for the authorization code flow.
+
+    Authorization codes are:
+    - Single-use (marked as used after exchange)
+    - Short-lived (10 minutes default)
+    - Bound to specific client, user, redirect_uri
+    - Support PKCE (code_challenge/code_challenge_method)
+
+    Security considerations:
+    - Code must be cryptographically random (64 chars, URL-safe)
+    - Must validate redirect_uri matches exactly
+    - Must verify PKCE code_verifier for public clients
+    - Must be consumed within expiration time
+
+    Performance indexes (defined in migration 0002_add_performance_indexes.py):
+    - ix_perf_oauth_auth_codes_expires: expires_at WHERE used = false
+    """
+
+    __tablename__ = "oauth_authorization_codes"
+
+    # The authorization code (cryptographically random, URL-safe)
+    code = Column(String(128), unique=True, nullable=False, index=True)
+
+    # Client that requested the code
+    client_id = Column(
+        String(64),
+        ForeignKey("oauth_clients.client_id", ondelete="CASCADE"),
+        nullable=False,
+    )
+
+    # User who authorized the request
+    user_id = Column(
+        UUID(as_uuid=True),
+        ForeignKey("users.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+
+    # Redirect URI (must match exactly on token exchange)
+    redirect_uri = Column(String(2048), nullable=False)
+
+    # Granted scopes (space-separated)
+    scope = Column(String(1000), nullable=False, default="")
+
+    # PKCE support (required for public clients)
+    code_challenge = Column(String(128), nullable=True)
+    code_challenge_method = Column(String(10), nullable=True)  # "S256" or "plain"
+
+    # State parameter (for CSRF protection, returned to client)
+    state = Column(String(256), nullable=True)
+
+    # Nonce (for OpenID Connect, included in ID token)
+    nonce = Column(String(256), nullable=True)
+
+    # Expiration (codes are short-lived, typically 10 minutes)
+    expires_at = Column(DateTime(timezone=True), nullable=False)
+
+    # Single-use flag (set to True after successful exchange)
+    used = Column(Boolean, default=False, nullable=False)
+
+    # Relationships
+    client = relationship("OAuthClient", backref="authorization_codes")
+    user = relationship("User", backref="oauth_authorization_codes")
+
+    # Indexes for efficient cleanup queries
+    __table_args__ = (
+        Index("ix_oauth_authorization_codes_expires_at", "expires_at"),
+        Index("ix_oauth_authorization_codes_client_user", "client_id", "user_id"),
+    )
+
+    def __repr__(self):
+        return f"<OAuthAuthorizationCode {self.code[:8]}... for {self.client_id}>"
+
+    @property
+    def is_expired(self) -> bool:
+        """Check if the authorization code has expired."""
+        # Use timezone-aware comparison (datetime.utcnow() is deprecated)
+        now = datetime.now(UTC)
+        expires_at = self.expires_at
+        # Handle both timezone-aware and naive datetimes from DB
+        if expires_at.tzinfo is None:
+            expires_at = expires_at.replace(tzinfo=UTC)
+        return bool(now > expires_at)
+
+    @property
+    def is_valid(self) -> bool:
+        """Check if the authorization code is valid (not used, not expired)."""
+        return not self.used and not self.is_expired

backend/app/models/oauth_client.py

@@ -0,0 +1,67 @@
+"""OAuth client model for OAuth provider mode (MCP clients)."""
+
+from sqlalchemy import Boolean, Column, ForeignKey, String
+from sqlalchemy.dialects.postgresql import JSONB, UUID
+from sqlalchemy.orm import relationship
+
+from .base import Base, TimestampMixin, UUIDMixin
+
+
+class OAuthClient(Base, UUIDMixin, TimestampMixin):
+    """
+    Registered OAuth clients (for OAuth provider mode).
+
+    This model stores third-party applications that can authenticate
+    against this API using OAuth 2.0. Used for MCP (Model Context Protocol)
+    client authentication and API access.
+
+    NOTE: This is a skeleton implementation. The full OAuth provider
+    functionality (authorization endpoint, token endpoint, etc.) can be
+    expanded when needed.
+    """
+
+    __tablename__ = "oauth_clients"
+
+    # Client credentials
+    client_id = Column(String(64), unique=True, nullable=False, index=True)
+    client_secret_hash = Column(
+        String(255), nullable=True
+    )  # NULL for public clients (PKCE)
+
+    # Client metadata
+    client_name = Column(String(255), nullable=False)
+    client_description = Column(String(1000), nullable=True)
+
+    # Client type: "public" (SPA, mobile) or "confidential" (server-side)
+    client_type = Column(String(20), nullable=False, default="public")
+
+    # Allowed redirect URIs (JSON array)
+    redirect_uris = Column(JSONB, nullable=False, default=list)
+
+    # Allowed scopes (JSON array of scope names)
+    allowed_scopes = Column(JSONB, nullable=False, default=list)
+
+    # Token lifetimes (in seconds)
+    access_token_lifetime = Column(String(10), nullable=False, default="3600")  # 1 hour
+    refresh_token_lifetime = Column(
+        String(10), nullable=False, default="604800"
+    )  # 7 days
+
+    # Status
+    is_active = Column(Boolean, default=True, nullable=False, index=True)
+
+    # Optional: owner user (for user-registered applications)
+    owner_user_id = Column(
+        UUID(as_uuid=True),
+        ForeignKey("users.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+
+    # MCP-specific: URL of the MCP server this client represents
+    mcp_server_url = Column(String(2048), nullable=True)
+
+    # Relationship
+    owner = relationship("User", backref="owned_oauth_clients")
+
+    def __repr__(self):
+        return f"<OAuthClient {self.client_name} ({self.client_id[:8]}...)>"

backend/app/models/oauth_provider_token.py

@@ -0,0 +1,162 @@
+"""OAuth provider token models for OAuth provider mode."""
+
+from datetime import UTC, datetime
+
+from sqlalchemy import Boolean, Column, DateTime, ForeignKey, Index, String
+from sqlalchemy.dialects.postgresql import UUID
+from sqlalchemy.orm import relationship
+
+from .base import Base, TimestampMixin, UUIDMixin
+
+
+class OAuthProviderRefreshToken(Base, UUIDMixin, TimestampMixin):
+    """
+    OAuth 2.0 Refresh Token for the OAuth provider.
+
+    Refresh tokens are:
+    - Opaque (stored as hash in DB, actual token given to client)
+    - Long-lived (configurable, default 30 days)
+    - Revocable (via revoked flag or deletion)
+    - Bound to specific client, user, and scope
+
+    Access tokens are JWTs and not stored in DB (self-contained).
+    This model only tracks refresh tokens for revocation support.
+
+    Security considerations:
+    - Store token hash, not plaintext
+    - Support token rotation (new refresh token on use)
+    - Track last used time for security auditing
+    - Support revocation by user, client, or admin
+
+    Performance indexes (defined in migration 0002_add_performance_indexes.py):
+    - ix_perf_oauth_refresh_tokens_expires: expires_at WHERE revoked = false
+    """
+
+    __tablename__ = "oauth_provider_refresh_tokens"
+
+    # Hash of the refresh token (SHA-256)
+    # We store hash, not plaintext, for security
+    token_hash = Column(String(64), unique=True, nullable=False, index=True)
+
+    # Unique token ID (JTI) - used in JWT access tokens to reference this refresh token
+    jti = Column(String(64), unique=True, nullable=False, index=True)
+
+    # Client that owns this token
+    client_id = Column(
+        String(64),
+        ForeignKey("oauth_clients.client_id", ondelete="CASCADE"),
+        nullable=False,
+    )
+
+    # User who authorized this token
+    user_id = Column(
+        UUID(as_uuid=True),
+        ForeignKey("users.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+
+    # Granted scopes (space-separated)
+    scope = Column(String(1000), nullable=False, default="")
+
+    # Token expiration
+    expires_at = Column(DateTime(timezone=True), nullable=False)
+
+    # Revocation flag
+    revoked = Column(Boolean, default=False, nullable=False, index=True)
+
+    # Last used timestamp (for security auditing)
+    last_used_at = Column(DateTime(timezone=True), nullable=True)
+
+    # Device/session info (optional, for user visibility)
+    device_info = Column(String(500), nullable=True)
+    ip_address = Column(String(45), nullable=True)
+
+    # Relationships
+    client = relationship("OAuthClient", backref="refresh_tokens")
+    user = relationship("User", backref="oauth_provider_refresh_tokens")
+
+    # Indexes
+    __table_args__ = (
+        Index("ix_oauth_provider_refresh_tokens_expires_at", "expires_at"),
+        Index("ix_oauth_provider_refresh_tokens_client_user", "client_id", "user_id"),
+        Index(
+            "ix_oauth_provider_refresh_tokens_user_revoked",
+            "user_id",
+            "revoked",
+        ),
+    )
+
+    def __repr__(self):
+        status = "revoked" if self.revoked else "active"
+        return f"<OAuthProviderRefreshToken {self.jti[:8]}... ({status})>"
+
+    @property
+    def is_expired(self) -> bool:
+        """Check if the refresh token has expired."""
+        # Use timezone-aware comparison (datetime.utcnow() is deprecated)
+        now = datetime.now(UTC)
+        expires_at = self.expires_at
+        # Handle both timezone-aware and naive datetimes from DB
+        if expires_at.tzinfo is None:
+            expires_at = expires_at.replace(tzinfo=UTC)
+        return bool(now > expires_at)
+
+    @property
+    def is_valid(self) -> bool:
+        """Check if the refresh token is valid (not revoked, not expired)."""
+        return not self.revoked and not self.is_expired
+
+
+class OAuthConsent(Base, UUIDMixin, TimestampMixin):
+    """
+    OAuth consent record - remembers user consent for a client.
+
+    When a user grants consent to an OAuth client, we store the record
+    so they don't have to re-consent on subsequent authorizations
+    (unless scopes change).
+
+    This enables a better UX - users only see consent screen once per client,
+    unless the client requests additional scopes.
+    """
+
+    __tablename__ = "oauth_consents"
+
+    # User who granted consent
+    user_id = Column(
+        UUID(as_uuid=True),
+        ForeignKey("users.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+
+    # Client that received consent
+    client_id = Column(
+        String(64),
+        ForeignKey("oauth_clients.client_id", ondelete="CASCADE"),
+        nullable=False,
+    )
+
+    # Granted scopes (space-separated)
+    granted_scopes = Column(String(1000), nullable=False, default="")
+
+    # Relationships
+    client = relationship("OAuthClient", backref="consents")
+    user = relationship("User", backref="oauth_consents")
+
+    # Unique constraint: one consent record per user+client
+    __table_args__ = (
+        Index(
+            "ix_oauth_consents_user_client",
+            "user_id",
+            "client_id",
+            unique=True,
+        ),
+    )
+
+    def __repr__(self):
+        return f"<OAuthConsent user={self.user_id} client={self.client_id}>"
+
+    def has_scopes(self, requested_scopes: list[str]) -> bool:
+        """Check if all requested scopes are already granted."""
+        granted = set(self.granted_scopes.split()) if self.granted_scopes else set()
+        requested = set(requested_scopes)
+        return requested.issubset(granted)

backend/app/models/oauth_state.py

@@ -0,0 +1,45 @@
+"""OAuth state model for CSRF protection during OAuth flows."""
+
+from sqlalchemy import Column, DateTime, String
+from sqlalchemy.dialects.postgresql import UUID
+
+from .base import Base, TimestampMixin, UUIDMixin
+
+
+class OAuthState(Base, UUIDMixin, TimestampMixin):
+    """
+    Temporary storage for OAuth state parameters.
+
+    Prevents CSRF attacks during OAuth flows by storing a random state
+    value that must match on callback. Also stores PKCE code_verifier
+    for the Authorization Code flow with PKCE.
+
+    These records are short-lived (10 minutes by default) and should
+    be deleted after use or expiration.
+    """
+
+    __tablename__ = "oauth_states"
+
+    # Random state parameter (CSRF protection)
+    state = Column(String(255), unique=True, nullable=False, index=True)
+
+    # PKCE code_verifier (used to generate code_challenge)
+    code_verifier = Column(String(128), nullable=True)
+
+    # OIDC nonce for ID token replay protection
+    nonce = Column(String(255), nullable=True)
+
+    # OAuth provider (google, github, etc.)
+    provider = Column(String(50), nullable=False)
+
+    # Original redirect URI (for callback validation)
+    redirect_uri = Column(String(500), nullable=True)
+
+    # User ID if this is an account linking flow (user is already logged in)
+    user_id = Column(UUID(as_uuid=True), nullable=True)
+
+    # Expiration time
+    expires_at = Column(DateTime(timezone=True), nullable=False)
+
+    def __repr__(self):
+        return f"<OAuthState {self.state[:8]}... ({self.provider})>"

backend/app/models/organization.py

@@ -1,5 +1,5 @@
 # app/models/organization.py
-from sqlalchemy import Column, String, Boolean, Text, Index
+from sqlalchemy import Boolean, Column, Index, String, Text
 from sqlalchemy.dialects.postgresql import JSONB
 from sqlalchemy.orm import relationship
 
@@ -10,8 +10,12 @@ class Organization(Base, UUIDMixin, TimestampMixin):
     """
     Organization model for multi-tenant support.
     Users can belong to multiple organizations with different roles.
+
+    Performance indexes (defined in migration 0002_add_performance_indexes.py):
+    - ix_perf_organizations_slug_lower: LOWER(slug) WHERE is_active = true
     """
-    __tablename__ = 'organizations'
+
+    __tablename__ = "organizations"
 
     name = Column(String(255), nullable=False, index=True)
     slug = Column(String(255), unique=True, nullable=False, index=True)
@@ -20,11 +24,13 @@ class Organization(Base, UUIDMixin, TimestampMixin):
     settings = Column(JSONB, default={})
 
     # Relationships
-    user_organizations = relationship("UserOrganization", back_populates="organization", cascade="all, delete-orphan")
+    user_organizations = relationship(
+        "UserOrganization", back_populates="organization", cascade="all, delete-orphan"
+    )
 
     __table_args__ = (
-        Index('ix_organizations_name_active', 'name', 'is_active'),
-        Index('ix_organizations_slug_active', 'slug', 'is_active'),
+        Index("ix_organizations_name_active", "name", "is_active"),
+        Index("ix_organizations_slug_active", "slug", "is_active"),
     )
 
     def __repr__(self):

backend/app/models/user.py

@@ -1,4 +1,4 @@
-from sqlalchemy import Column, String, Boolean, DateTime
+from sqlalchemy import Boolean, Column, DateTime, String
 from sqlalchemy.dialects.postgresql import JSONB
 from sqlalchemy.orm import relationship
 
@@ -6,20 +6,45 @@ from .base import Base, TimestampMixin, UUIDMixin
 
 
 class User(Base, UUIDMixin, TimestampMixin):
-    __tablename__ = 'users'
+    """
+    User model for authentication and profile data.
+
+    Performance indexes (defined in migration 0002_add_performance_indexes.py):
+    - ix_perf_users_email_lower: LOWER(email) WHERE deleted_at IS NULL
+    - ix_perf_users_active: is_active WHERE deleted_at IS NULL
+    """
+
+    __tablename__ = "users"
 
     email = Column(String(255), unique=True, nullable=False, index=True)
-    password_hash = Column(String(255), nullable=False)
+    # Nullable to support OAuth-only users who never set a password
+    password_hash = Column(String(255), nullable=True)
     first_name = Column(String(100), nullable=False, default="user")
     last_name = Column(String(100), nullable=True)
     phone_number = Column(String(20))
     is_active = Column(Boolean, default=True, nullable=False, index=True)
     is_superuser = Column(Boolean, default=False, nullable=False, index=True)
     preferences = Column(JSONB)
+    locale = Column(String(10), nullable=True, index=True)
     deleted_at = Column(DateTime(timezone=True), nullable=True, index=True)
 
     # Relationships
-    user_organizations = relationship("UserOrganization", back_populates="user", cascade="all, delete-orphan")
+    user_organizations = relationship(
+        "UserOrganization", back_populates="user", cascade="all, delete-orphan"
+    )
+    oauth_accounts = relationship(
+        "OAuthAccount", back_populates="user", cascade="all, delete-orphan"
+    )
+
+    @property
+    def has_password(self) -> bool:
+        """Check if user can login with password (not OAuth-only)."""
+        return self.password_hash is not None
+
+    @property
+    def can_remove_oauth(self) -> bool:
+        """Check if user can safely remove an OAuth account link."""
+        return self.has_password or len(self.oauth_accounts) > 1
 
     def __repr__(self):
-        return f"<User {self.email}>"
+        return f"<User {self.email}>"

backend/app/models/user_organization.py

@@ -1,7 +1,7 @@
 # app/models/user_organization.py
 from enum import Enum as PyEnum
 
-from sqlalchemy import Column, ForeignKey, Boolean, String, Index, Enum
+from sqlalchemy import Boolean, Column, Enum, ForeignKey, Index, String
 from sqlalchemy.dialects.postgresql import UUID as PGUUID
 from sqlalchemy.orm import relationship
 
@@ -14,6 +14,7 @@ class OrganizationRole(str, PyEnum):
     These provide a baseline role system that can be optionally used.
     Projects can extend this or implement their own permission system.
     """
+
     OWNER = "owner"  # Full control over organization
     ADMIN = "admin"  # Can manage users and settings
     MEMBER = "member"  # Regular member with standard access
@@ -25,25 +26,41 @@ class UserOrganization(Base, TimestampMixin):
     Junction table for many-to-many relationship between Users and Organizations.
     Includes role information for flexible RBAC.
     """
-    __tablename__ = 'user_organizations'
 
-    user_id = Column(PGUUID(as_uuid=True), ForeignKey('users.id', ondelete='CASCADE'), primary_key=True)
-    organization_id = Column(PGUUID(as_uuid=True), ForeignKey('organizations.id', ondelete='CASCADE'), primary_key=True)
+    __tablename__ = "user_organizations"
 
-    role = Column(Enum(OrganizationRole), default=OrganizationRole.MEMBER, nullable=False, index=True)
+    user_id = Column(
+        PGUUID(as_uuid=True),
+        ForeignKey("users.id", ondelete="CASCADE"),
+        primary_key=True,
+    )
+    organization_id = Column(
+        PGUUID(as_uuid=True),
+        ForeignKey("organizations.id", ondelete="CASCADE"),
+        primary_key=True,
+    )
+
+    role: Column[OrganizationRole] = Column(
+        Enum(OrganizationRole),
+        default=OrganizationRole.MEMBER,
+        nullable=False,
+        # Note: index defined in __table_args__ as ix_user_org_role
+    )
     is_active = Column(Boolean, default=True, nullable=False, index=True)
 
     # Optional: Custom permissions override for specific users
-    custom_permissions = Column(String(500), nullable=True)  # JSON array of permission strings
+    custom_permissions = Column(
+        String(500), nullable=True
+    )  # JSON array of permission strings
 
     # Relationships
     user = relationship("User", back_populates="user_organizations")
     organization = relationship("Organization", back_populates="user_organizations")
 
     __table_args__ = (
-        Index('ix_user_org_user_active', 'user_id', 'is_active'),
-        Index('ix_user_org_org_active', 'organization_id', 'is_active'),
-        Index('ix_user_org_role', 'role'),
+        Index("ix_user_org_user_active", "user_id", "is_active"),
+        Index("ix_user_org_org_active", "organization_id", "is_active"),
+        Index("ix_user_org_role", "role"),
     )
 
     def __repr__(self):

backend/app/models/user_session.py

@@ -6,7 +6,10 @@ This allows users to:
 - Logout from specific devices
 - Manage their active sessions
 """
-from sqlalchemy import Column, String, Boolean, DateTime, ForeignKey, Index
+
+from datetime import UTC
+
+from sqlalchemy import Boolean, Column, DateTime, ForeignKey, Index, String
 from sqlalchemy.dialects.postgresql import UUID
 from sqlalchemy.orm import relationship
 
@@ -19,20 +22,31 @@ class UserSession(Base, UUIDMixin, TimestampMixin):
 
     Each time a user logs in from a device, a new session is created.
     Sessions are identified by the refresh token JTI (JWT ID).
+
+    Performance indexes (defined in migration 0002_add_performance_indexes.py):
+    - ix_perf_user_sessions_expires: expires_at WHERE is_active = true
     """
-    __tablename__ = 'user_sessions'
+
+    __tablename__ = "user_sessions"
 
     # Foreign key to user
-    user_id = Column(UUID(as_uuid=True), ForeignKey('users.id', ondelete='CASCADE'), nullable=False, index=True)
+    user_id = Column(
+        UUID(as_uuid=True),
+        ForeignKey("users.id", ondelete="CASCADE"),
+        nullable=False,
+        index=True,
+    )
 
     # Refresh token identifier (JWT ID from the refresh token)
     refresh_token_jti = Column(String(255), unique=True, nullable=False, index=True)
 
     # Device information
     device_name = Column(String(255), nullable=True)  # "iPhone 14", "Chrome on MacBook"
-    device_id = Column(String(255), nullable=True)    # Persistent device identifier (from client)
-    ip_address = Column(String(45), nullable=True)    # IPv4 (15 chars) or IPv6 (45 chars)
-    user_agent = Column(String(500), nullable=True)   # Browser/app user agent
+    device_id = Column(
+        String(255), nullable=True
+    )  # Persistent device identifier (from client)
+    ip_address = Column(String(45), nullable=True)  # IPv4 (15 chars) or IPv6 (45 chars)
+    user_agent = Column(String(500), nullable=True)  # Browser/app user agent
 
     # Session timing
     last_used_at = Column(DateTime(timezone=True), nullable=False)
@@ -50,8 +64,8 @@ class UserSession(Base, UUIDMixin, TimestampMixin):
 
     # Composite indexes for performance (defined in migration)
     __table_args__ = (
-        Index('ix_user_sessions_user_active', 'user_id', 'is_active'),
-        Index('ix_user_sessions_jti_active', 'refresh_token_jti', 'is_active'),
+        Index("ix_user_sessions_user_active", "user_id", "is_active"),
+        Index("ix_user_sessions_jti_active", "refresh_token_jti", "is_active"),
     )
 
     def __repr__(self):
@@ -60,21 +74,28 @@ class UserSession(Base, UUIDMixin, TimestampMixin):
     @property
     def is_expired(self) -> bool:
         """Check if session has expired."""
-        from datetime import datetime, timezone
-        return self.expires_at < datetime.now(timezone.utc)
+        from datetime import datetime
+
+        now = datetime.now(UTC)
+        expires_at = self.expires_at
+        if expires_at.tzinfo is None:
+            expires_at = expires_at.replace(tzinfo=UTC)
+        return bool(expires_at < now)
 
     def to_dict(self):
         """Convert session to dictionary for serialization."""
         return {
-            'id': str(self.id),
-            'user_id': str(self.user_id),
-            'device_name': self.device_name,
-            'device_id': self.device_id,
-            'ip_address': self.ip_address,
-            'last_used_at': self.last_used_at.isoformat() if self.last_used_at else None,
-            'expires_at': self.expires_at.isoformat() if self.expires_at else None,
-            'is_active': self.is_active,
-            'location_city': self.location_city,
-            'location_country': self.location_country,
-            'created_at': self.created_at.isoformat() if self.created_at else None,
+            "id": str(self.id),
+            "user_id": str(self.user_id),
+            "device_name": self.device_name,
+            "device_id": self.device_id,
+            "ip_address": self.ip_address,
+            "last_used_at": self.last_used_at.isoformat()
+            if self.last_used_at
+            else None,
+            "expires_at": self.expires_at.isoformat() if self.expires_at else None,
+            "is_active": self.is_active,
+            "location_city": self.location_city,
+            "location_country": self.location_country,
+            "created_at": self.created_at.isoformat() if self.created_at else None,
         }

backend/app/repositories/__init__.py

@@ -0,0 +1,39 @@
+# app/repositories/__init__.py
+"""Repository layer — all database access goes through these classes."""
+
+from app.repositories.oauth_account import OAuthAccountRepository, oauth_account_repo
+from app.repositories.oauth_authorization_code import (
+    OAuthAuthorizationCodeRepository,
+    oauth_authorization_code_repo,
+)
+from app.repositories.oauth_client import OAuthClientRepository, oauth_client_repo
+from app.repositories.oauth_consent import OAuthConsentRepository, oauth_consent_repo
+from app.repositories.oauth_provider_token import (
+    OAuthProviderTokenRepository,
+    oauth_provider_token_repo,
+)
+from app.repositories.oauth_state import OAuthStateRepository, oauth_state_repo
+from app.repositories.organization import OrganizationRepository, organization_repo
+from app.repositories.session import SessionRepository, session_repo
+from app.repositories.user import UserRepository, user_repo
+
+__all__ = [
+    "OAuthAccountRepository",
+    "OAuthAuthorizationCodeRepository",
+    "OAuthClientRepository",
+    "OAuthConsentRepository",
+    "OAuthProviderTokenRepository",
+    "OAuthStateRepository",
+    "OrganizationRepository",
+    "SessionRepository",
+    "UserRepository",
+    "oauth_account_repo",
+    "oauth_authorization_code_repo",
+    "oauth_client_repo",
+    "oauth_consent_repo",
+    "oauth_provider_token_repo",
+    "oauth_state_repo",
+    "organization_repo",
+    "session_repo",
+    "user_repo",
+]

backend/app/repositories/base.py

@@ -1,21 +1,28 @@
-# app/crud/base_async.py
+# app/repositories/base.py
 """
-Async CRUD operations base class using SQLAlchemy 2.0 async patterns.
+Base repository class for async database operations using SQLAlchemy 2.0 async patterns.
 
 Provides reusable create, read, update, and delete operations for all models.
 """
+
 import logging
 import uuid
-from typing import Any, Dict, Generic, List, Optional, Type, TypeVar, Union, Tuple
+from datetime import UTC
+from typing import Any, TypeVar
 
 from fastapi.encoders import jsonable_encoder
 from pydantic import BaseModel
 from sqlalchemy import func, select
-from sqlalchemy.exc import IntegrityError, OperationalError, DataError
+from sqlalchemy.exc import DataError, IntegrityError, OperationalError
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy.orm import Load
 
 from app.core.database import Base
+from app.core.repository_exceptions import (
+    DuplicateEntryError,
+    IntegrityConstraintError,
+    InvalidInputError,
+)
 
 logger = logging.getLogger(__name__)
 
@@ -24,12 +31,16 @@ CreateSchemaType = TypeVar("CreateSchemaType", bound=BaseModel)
 UpdateSchemaType = TypeVar("UpdateSchemaType", bound=BaseModel)
 
 
-class CRUDBase(Generic[ModelType, CreateSchemaType, UpdateSchemaType]):
-    """Async CRUD operations for a model."""
+class BaseRepository[
+    ModelType: Base,
+    CreateSchemaType: BaseModel,
+    UpdateSchemaType: BaseModel,
+]:
+    """Async repository operations for a model."""
 
-    def __init__(self, model: Type[ModelType]):
+    def __init__(self, model: type[ModelType]):
         """
-        CRUD object with default async methods to Create, Read, Update, Delete.
+        Repository object with default async methods to Create, Read, Update, Delete.
 
         Parameters:
             model: A SQLAlchemy model class
@@ -37,11 +48,8 @@ class CRUDBase(Generic[ModelType, CreateSchemaType, UpdateSchemaType]):
         self.model = model
 
     async def get(
-        self,
-        db: AsyncSession,
-        id: str,
-        options: Optional[List[Load]] = None
-    ) -> Optional[ModelType]:
+        self, db: AsyncSession, id: str, options: list[Load] | None = None
+    ) -> ModelType | None:
         """
         Get a single record by ID with UUID validation and optional eager loading.
 
@@ -53,26 +61,19 @@ class CRUDBase(Generic[ModelType, CreateSchemaType, UpdateSchemaType]):
 
         Returns:
             Model instance or None if not found
-
-        Example:
-            # Eager load user relationship
-            from sqlalchemy.orm import joinedload
-            session = await session_crud.get(db, id=session_id, options=[joinedload(UserSession.user)])
         """
-        # Validate UUID format and convert to UUID object if string
         try:
             if isinstance(id, uuid.UUID):
                 uuid_obj = id
             else:
                 uuid_obj = uuid.UUID(str(id))
         except (ValueError, AttributeError, TypeError) as e:
-            logger.warning(f"Invalid UUID format: {id} - {str(e)}")
+            logger.warning("Invalid UUID format: %s - %s", id, e)
             return None
 
         try:
             query = select(self.model).where(self.model.id == uuid_obj)
 
-            # Apply eager loading options if provided
             if options:
                 for option in options:
                     query = query.options(option)
@@ -80,7 +81,9 @@ class CRUDBase(Generic[ModelType, CreateSchemaType, UpdateSchemaType]):
             result = await db.execute(query)
             return result.scalar_one_or_none()
         except Exception as e:
-            logger.error(f"Error retrieving {self.model.__name__} with id {id}: {str(e)}")
+            logger.error(
+                "Error retrieving %s with id %s: %s", self.model.__name__, id, e
+            )
             raise
 
     async def get_multi(
@@ -89,32 +92,21 @@ class CRUDBase(Generic[ModelType, CreateSchemaType, UpdateSchemaType]):
         *,
         skip: int = 0,
         limit: int = 100,
-        options: Optional[List[Load]] = None
-    ) -> List[ModelType]:
+        options: list[Load] | None = None,
+    ) -> list[ModelType]:
         """
         Get multiple records with pagination validation and optional eager loading.
-
-        Args:
-            db: Database session
-            skip: Number of records to skip
-            limit: Maximum number of records to return
-            options: Optional list of SQLAlchemy load options for eager loading
-
-        Returns:
-            List of model instances
         """
-        # Validate pagination parameters
         if skip < 0:
-            raise ValueError("skip must be non-negative")
+            raise InvalidInputError("skip must be non-negative")
         if limit < 0:
-            raise ValueError("limit must be non-negative")
+            raise InvalidInputError("limit must be non-negative")
         if limit > 1000:
-            raise ValueError("Maximum limit is 1000")
+            raise InvalidInputError("Maximum limit is 1000")
 
         try:
-            query = select(self.model).offset(skip).limit(limit)
+            query = select(self.model).order_by(self.model.id).offset(skip).limit(limit)
 
-            # Apply eager loading options if provided
             if options:
                 for option in options:
                     query = query.options(option)
@@ -122,16 +114,19 @@ class CRUDBase(Generic[ModelType, CreateSchemaType, UpdateSchemaType]):
             result = await db.execute(query)
             return list(result.scalars().all())
         except Exception as e:
-            logger.error(f"Error retrieving multiple {self.model.__name__} records: {str(e)}")
+            logger.error(
+                "Error retrieving multiple %s records: %s", self.model.__name__, e
+            )
             raise
 
-    async def create(self, db: AsyncSession, *, obj_in: CreateSchemaType) -> ModelType:  # pragma: no cover
+    async def create(
+        self, db: AsyncSession, *, obj_in: CreateSchemaType
+    ) -> ModelType:  # pragma: no cover
         """Create a new record with error handling.
 
         NOTE: This method is defensive code that's never called in practice.
-        All CRUD subclasses (CRUDUser, CRUDOrganization, CRUDSession) override this method
-        with their own implementations, so the base implementation and its exception handlers
-        are never executed. Marked as pragma: no cover to avoid false coverage gaps.
+        All repository subclasses override this method with their own implementations.
+        Marked as pragma: no cover to avoid false coverage gaps.
         """
         try:  # pragma: no cover
             obj_in_data = jsonable_encoder(obj_in)
@@ -142,19 +137,27 @@ class CRUDBase(Generic[ModelType, CreateSchemaType, UpdateSchemaType]):
             return db_obj
         except IntegrityError as e:  # pragma: no cover
             await db.rollback()
-            error_msg = str(e.orig) if hasattr(e, 'orig') else str(e)
+            error_msg = str(e.orig) if hasattr(e, "orig") else str(e)
             if "unique" in error_msg.lower() or "duplicate" in error_msg.lower():
-                logger.warning(f"Duplicate entry attempted for {self.model.__name__}: {error_msg}")
-                raise ValueError(f"A {self.model.__name__} with this data already exists")
-            logger.error(f"Integrity error creating {self.model.__name__}: {error_msg}")
-            raise ValueError(f"Database integrity error: {error_msg}")
+                logger.warning(
+                    "Duplicate entry attempted for %s: %s",
+                    self.model.__name__,
+                    error_msg,
+                )
+                raise DuplicateEntryError(
+                    f"A {self.model.__name__} with this data already exists"
+                )
+            logger.error(
+                "Integrity error creating %s: %s", self.model.__name__, error_msg
+            )
+            raise IntegrityConstraintError(f"Database integrity error: {error_msg}")
         except (OperationalError, DataError) as e:  # pragma: no cover
             await db.rollback()
-            logger.error(f"Database error creating {self.model.__name__}: {str(e)}")
-            raise ValueError(f"Database operation failed: {str(e)}")
+            logger.error("Database error creating %s: %s", self.model.__name__, e)
+            raise IntegrityConstraintError(f"Database operation failed: {e!s}")
         except Exception as e:  # pragma: no cover
             await db.rollback()
-            logger.error(f"Unexpected error creating {self.model.__name__}: {str(e)}", exc_info=True)
+            logger.exception("Unexpected error creating %s: %s", self.model.__name__, e)
             raise
 
     async def update(
@@ -162,7 +165,7 @@ class CRUDBase(Generic[ModelType, CreateSchemaType, UpdateSchemaType]):
         db: AsyncSession,
         *,
         db_obj: ModelType,
-        obj_in: Union[UpdateSchemaType, Dict[str, Any]]
+        obj_in: UpdateSchemaType | dict[str, Any],
     ) -> ModelType:
         """Update a record with error handling."""
         try:
@@ -182,31 +185,38 @@ class CRUDBase(Generic[ModelType, CreateSchemaType, UpdateSchemaType]):
             return db_obj
         except IntegrityError as e:
             await db.rollback()
-            error_msg = str(e.orig) if hasattr(e, 'orig') else str(e)
+            error_msg = str(e.orig) if hasattr(e, "orig") else str(e)
             if "unique" in error_msg.lower() or "duplicate" in error_msg.lower():
-                logger.warning(f"Duplicate entry attempted for {self.model.__name__}: {error_msg}")
-                raise ValueError(f"A {self.model.__name__} with this data already exists")
-            logger.error(f"Integrity error updating {self.model.__name__}: {error_msg}")
-            raise ValueError(f"Database integrity error: {error_msg}")
+                logger.warning(
+                    "Duplicate entry attempted for %s: %s",
+                    self.model.__name__,
+                    error_msg,
+                )
+                raise DuplicateEntryError(
+                    f"A {self.model.__name__} with this data already exists"
+                )
+            logger.error(
+                "Integrity error updating %s: %s", self.model.__name__, error_msg
+            )
+            raise IntegrityConstraintError(f"Database integrity error: {error_msg}")
         except (OperationalError, DataError) as e:
             await db.rollback()
-            logger.error(f"Database error updating {self.model.__name__}: {str(e)}")
-            raise ValueError(f"Database operation failed: {str(e)}")
+            logger.error("Database error updating %s: %s", self.model.__name__, e)
+            raise IntegrityConstraintError(f"Database operation failed: {e!s}")
         except Exception as e:
             await db.rollback()
-            logger.error(f"Unexpected error updating {self.model.__name__}: {str(e)}", exc_info=True)
+            logger.exception("Unexpected error updating %s: %s", self.model.__name__, e)
             raise
 
-    async def remove(self, db: AsyncSession, *, id: str) -> Optional[ModelType]:
+    async def remove(self, db: AsyncSession, *, id: str) -> ModelType | None:
         """Delete a record with error handling and null check."""
-        # Validate UUID format and convert to UUID object if string
         try:
             if isinstance(id, uuid.UUID):
                 uuid_obj = id
             else:
                 uuid_obj = uuid.UUID(str(id))
         except (ValueError, AttributeError, TypeError) as e:
-            logger.warning(f"Invalid UUID format for deletion: {id} - {str(e)}")
+            logger.warning("Invalid UUID format for deletion: %s - %s", id, e)
             return None
 
         try:
@@ -216,7 +226,9 @@ class CRUDBase(Generic[ModelType, CreateSchemaType, UpdateSchemaType]):
             obj = result.scalar_one_or_none()
 
             if obj is None:
-                logger.warning(f"{self.model.__name__} with id {id} not found for deletion")
+                logger.warning(
+                    "%s with id %s not found for deletion", self.model.__name__, id
+                )
                 return None
 
             await db.delete(obj)
@@ -224,12 +236,18 @@ class CRUDBase(Generic[ModelType, CreateSchemaType, UpdateSchemaType]):
             return obj
         except IntegrityError as e:
             await db.rollback()
-            error_msg = str(e.orig) if hasattr(e, 'orig') else str(e)
-            logger.error(f"Integrity error deleting {self.model.__name__}: {error_msg}")
-            raise ValueError(f"Cannot delete {self.model.__name__}: referenced by other records")
+            error_msg = str(e.orig) if hasattr(e, "orig") else str(e)
+            logger.error(
+                "Integrity error deleting %s: %s", self.model.__name__, error_msg
+            )
+            raise IntegrityConstraintError(
+                f"Cannot delete {self.model.__name__}: referenced by other records"
+            )
         except Exception as e:
             await db.rollback()
-            logger.error(f"Error deleting {self.model.__name__} with id {id}: {str(e)}", exc_info=True)
+            logger.exception(
+                "Error deleting %s with id %s: %s", self.model.__name__, id, e
+            )
             raise
 
     async def get_multi_with_total(
@@ -238,67 +256,57 @@ class CRUDBase(Generic[ModelType, CreateSchemaType, UpdateSchemaType]):
         *,
         skip: int = 0,
         limit: int = 100,
-        sort_by: Optional[str] = None,
+        sort_by: str | None = None,
         sort_order: str = "asc",
-        filters: Optional[Dict[str, Any]] = None
-    ) -> Tuple[List[ModelType], int]:
+        filters: dict[str, Any] | None = None,
+    ) -> tuple[list[ModelType], int]:  # pragma: no cover
         """
         Get multiple records with total count, filtering, and sorting.
 
-        Args:
-            db: Database session
-            skip: Number of records to skip
-            limit: Maximum number of records to return
-            sort_by: Field name to sort by (must be a valid model attribute)
-            sort_order: Sort order ("asc" or "desc")
-            filters: Dictionary of filters (field_name: value)
-
-        Returns:
-            Tuple of (items, total_count)
+        NOTE: This method is defensive code that's never called in practice.
+        All repository subclasses override this method with their own implementations.
+        Marked as pragma: no cover to avoid false coverage gaps.
         """
-        # Validate pagination parameters
         if skip < 0:
-            raise ValueError("skip must be non-negative")
+            raise InvalidInputError("skip must be non-negative")
         if limit < 0:
-            raise ValueError("limit must be non-negative")
+            raise InvalidInputError("limit must be non-negative")
         if limit > 1000:
-            raise ValueError("Maximum limit is 1000")
+            raise InvalidInputError("Maximum limit is 1000")
 
         try:
-            # Build base query
             query = select(self.model)
 
-            # Exclude soft-deleted records by default
-            if hasattr(self.model, 'deleted_at'):
+            if hasattr(self.model, "deleted_at"):
                 query = query.where(self.model.deleted_at.is_(None))
 
-            # Apply filters
             if filters:
                 for field, value in filters.items():
                     if hasattr(self.model, field) and value is not None:
                         query = query.where(getattr(self.model, field) == value)
 
-            # Get total count (before pagination)
             count_query = select(func.count()).select_from(query.alias())
             count_result = await db.execute(count_query)
             total = count_result.scalar_one()
 
-            # Apply sorting
             if sort_by and hasattr(self.model, sort_by):
                 sort_column = getattr(self.model, sort_by)
                 if sort_order.lower() == "desc":
                     query = query.order_by(sort_column.desc())
                 else:
                     query = query.order_by(sort_column.asc())
+            else:
+                query = query.order_by(self.model.id)
 
-            # Apply pagination
             query = query.offset(skip).limit(limit)
             items_result = await db.execute(query)
             items = list(items_result.scalars().all())
 
             return items, total
-        except Exception as e:
-            logger.error(f"Error retrieving paginated {self.model.__name__} records: {str(e)}")
+        except Exception as e:  # pragma: no cover
+            logger.error(
+                "Error retrieving paginated %s records: %s", self.model.__name__, e
+            )
             raise
 
     async def count(self, db: AsyncSession) -> int:
@@ -307,7 +315,7 @@ class CRUDBase(Generic[ModelType, CreateSchemaType, UpdateSchemaType]):
             result = await db.execute(select(func.count(self.model.id)))
             return result.scalar_one()
         except Exception as e:
-            logger.error(f"Error counting {self.model.__name__} records: {str(e)}")
+            logger.error("Error counting %s records: %s", self.model.__name__, e)
             raise
 
     async def exists(self, db: AsyncSession, id: str) -> bool:
@@ -315,22 +323,21 @@ class CRUDBase(Generic[ModelType, CreateSchemaType, UpdateSchemaType]):
         obj = await self.get(db, id=id)
         return obj is not None
 
-    async def soft_delete(self, db: AsyncSession, *, id: str) -> Optional[ModelType]:
+    async def soft_delete(self, db: AsyncSession, *, id: str) -> ModelType | None:
         """
         Soft delete a record by setting deleted_at timestamp.
 
         Only works if the model has a 'deleted_at' column.
         """
-        from datetime import datetime, timezone
+        from datetime import datetime
 
-        # Validate UUID format and convert to UUID object if string
         try:
             if isinstance(id, uuid.UUID):
                 uuid_obj = id
             else:
                 uuid_obj = uuid.UUID(str(id))
         except (ValueError, AttributeError, TypeError) as e:
-            logger.warning(f"Invalid UUID format for soft deletion: {id} - {str(e)}")
+            logger.warning("Invalid UUID format for soft deletion: %s - %s", id, e)
             return None
 
         try:
@@ -340,60 +347,66 @@ class CRUDBase(Generic[ModelType, CreateSchemaType, UpdateSchemaType]):
             obj = result.scalar_one_or_none()
 
             if obj is None:
-                logger.warning(f"{self.model.__name__} with id {id} not found for soft deletion")
+                logger.warning(
+                    "%s with id %s not found for soft deletion", self.model.__name__, id
+                )
                 return None
 
-            # Check if model supports soft deletes
-            if not hasattr(self.model, 'deleted_at'):
-                logger.error(f"{self.model.__name__} does not support soft deletes")
-                raise ValueError(f"{self.model.__name__} does not have a deleted_at column")
+            if not hasattr(self.model, "deleted_at"):
+                logger.error("%s does not support soft deletes", self.model.__name__)
+                raise InvalidInputError(
+                    f"{self.model.__name__} does not have a deleted_at column"
+                )
 
-            # Set deleted_at timestamp
-            obj.deleted_at = datetime.now(timezone.utc)
+            obj.deleted_at = datetime.now(UTC)
             db.add(obj)
             await db.commit()
             await db.refresh(obj)
             return obj
         except Exception as e:
             await db.rollback()
-            logger.error(f"Error soft deleting {self.model.__name__} with id {id}: {str(e)}", exc_info=True)
+            logger.exception(
+                "Error soft deleting %s with id %s: %s", self.model.__name__, id, e
+            )
             raise
 
-    async def restore(self, db: AsyncSession, *, id: str) -> Optional[ModelType]:
+    async def restore(self, db: AsyncSession, *, id: str) -> ModelType | None:
         """
         Restore a soft-deleted record by clearing the deleted_at timestamp.
 
         Only works if the model has a 'deleted_at' column.
         """
-        # Validate UUID format
         try:
             if isinstance(id, uuid.UUID):
                 uuid_obj = id
             else:
                 uuid_obj = uuid.UUID(str(id))
         except (ValueError, AttributeError, TypeError) as e:
-            logger.warning(f"Invalid UUID format for restoration: {id} - {str(e)}")
+            logger.warning("Invalid UUID format for restoration: %s - %s", id, e)
             return None
 
         try:
-            # Find the soft-deleted record
-            if hasattr(self.model, 'deleted_at'):
+            if hasattr(self.model, "deleted_at"):
                 result = await db.execute(
                     select(self.model).where(
-                        self.model.id == uuid_obj,
-                        self.model.deleted_at.isnot(None)
+                        self.model.id == uuid_obj, self.model.deleted_at.isnot(None)
                     )
                 )
                 obj = result.scalar_one_or_none()
             else:
-                logger.error(f"{self.model.__name__} does not support soft deletes")
-                raise ValueError(f"{self.model.__name__} does not have a deleted_at column")
+                logger.error("%s does not support soft deletes", self.model.__name__)
+                raise InvalidInputError(
+                    f"{self.model.__name__} does not have a deleted_at column"
+                )
 
             if obj is None:
-                logger.warning(f"Soft-deleted {self.model.__name__} with id {id} not found for restoration")
+                logger.warning(
+                    "Soft-deleted %s with id %s not found for restoration",
+                    self.model.__name__,
+                    id,
+                )
                 return None
 
-            # Clear deleted_at timestamp
             obj.deleted_at = None
             db.add(obj)
             await db.commit()
@@ -401,5 +414,7 @@ class CRUDBase(Generic[ModelType, CreateSchemaType, UpdateSchemaType]):
             return obj
         except Exception as e:
             await db.rollback()
-            logger.error(f"Error restoring {self.model.__name__} with id {id}: {str(e)}", exc_info=True)
+            logger.exception(
+                "Error restoring %s with id %s: %s", self.model.__name__, id, e
+            )
             raise

backend/app/repositories/oauth_account.py

@@ -0,0 +1,249 @@
+# app/repositories/oauth_account.py
+"""Repository for OAuthAccount model async database operations."""
+
+import logging
+from datetime import datetime
+from uuid import UUID
+
+from pydantic import BaseModel
+from sqlalchemy import and_, delete, select
+from sqlalchemy.exc import IntegrityError
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.orm import joinedload
+
+from app.core.repository_exceptions import DuplicateEntryError
+from app.models.oauth_account import OAuthAccount
+from app.repositories.base import BaseRepository
+from app.schemas.oauth import OAuthAccountCreate
+
+logger = logging.getLogger(__name__)
+
+
+class EmptySchema(BaseModel):
+    """Placeholder schema for repository operations that don't need update schemas."""
+
+
+class OAuthAccountRepository(
+    BaseRepository[OAuthAccount, OAuthAccountCreate, EmptySchema]
+):
+    """Repository for OAuth account links."""
+
+    async def get_by_provider_id(
+        self,
+        db: AsyncSession,
+        *,
+        provider: str,
+        provider_user_id: str,
+    ) -> OAuthAccount | None:
+        """Get OAuth account by provider and provider user ID."""
+        try:
+            result = await db.execute(
+                select(OAuthAccount)
+                .where(
+                    and_(
+                        OAuthAccount.provider == provider,
+                        OAuthAccount.provider_user_id == provider_user_id,
+                    )
+                )
+                .options(joinedload(OAuthAccount.user))
+            )
+            return result.scalar_one_or_none()
+        except Exception as e:  # pragma: no cover
+            logger.error(
+                "Error getting OAuth account for %s:%s: %s",
+                provider,
+                provider_user_id,
+                e,
+            )
+            raise
+
+    async def get_by_provider_email(
+        self,
+        db: AsyncSession,
+        *,
+        provider: str,
+        email: str,
+    ) -> OAuthAccount | None:
+        """Get OAuth account by provider and email."""
+        try:
+            result = await db.execute(
+                select(OAuthAccount)
+                .where(
+                    and_(
+                        OAuthAccount.provider == provider,
+                        OAuthAccount.provider_email == email,
+                    )
+                )
+                .options(joinedload(OAuthAccount.user))
+            )
+            return result.scalar_one_or_none()
+        except Exception as e:  # pragma: no cover
+            logger.error(
+                "Error getting OAuth account for %s email %s: %s", provider, email, e
+            )
+            raise
+
+    async def get_user_accounts(
+        self,
+        db: AsyncSession,
+        *,
+        user_id: str | UUID,
+    ) -> list[OAuthAccount]:
+        """Get all OAuth accounts linked to a user."""
+        try:
+            user_uuid = UUID(str(user_id)) if isinstance(user_id, str) else user_id
+
+            result = await db.execute(
+                select(OAuthAccount)
+                .where(OAuthAccount.user_id == user_uuid)
+                .order_by(OAuthAccount.created_at.desc())
+            )
+            return list(result.scalars().all())
+        except Exception as e:  # pragma: no cover
+            logger.error("Error getting OAuth accounts for user %s: %s", user_id, e)
+            raise
+
+    async def get_user_account_by_provider(
+        self,
+        db: AsyncSession,
+        *,
+        user_id: str | UUID,
+        provider: str,
+    ) -> OAuthAccount | None:
+        """Get a specific OAuth account for a user and provider."""
+        try:
+            user_uuid = UUID(str(user_id)) if isinstance(user_id, str) else user_id
+
+            result = await db.execute(
+                select(OAuthAccount).where(
+                    and_(
+                        OAuthAccount.user_id == user_uuid,
+                        OAuthAccount.provider == provider,
+                    )
+                )
+            )
+            return result.scalar_one_or_none()
+        except Exception as e:  # pragma: no cover
+            logger.error(
+                "Error getting OAuth account for user %s, provider %s: %s",
+                user_id,
+                provider,
+                e,
+            )
+            raise
+
+    async def create_account(
+        self, db: AsyncSession, *, obj_in: OAuthAccountCreate
+    ) -> OAuthAccount:
+        """Create a new OAuth account link."""
+        try:
+            db_obj = OAuthAccount(
+                user_id=obj_in.user_id,
+                provider=obj_in.provider,
+                provider_user_id=obj_in.provider_user_id,
+                provider_email=obj_in.provider_email,
+                access_token=obj_in.access_token,
+                refresh_token=obj_in.refresh_token,
+                token_expires_at=obj_in.token_expires_at,
+            )
+            db.add(db_obj)
+            await db.commit()
+            await db.refresh(db_obj)
+
+            logger.info(
+                "OAuth account created: %s linked to user %s",
+                obj_in.provider,
+                obj_in.user_id,
+            )
+            return db_obj
+        except IntegrityError as e:  # pragma: no cover
+            await db.rollback()
+            error_msg = str(e.orig) if hasattr(e, "orig") else str(e)
+            if "uq_oauth_provider_user" in error_msg.lower():
+                logger.warning(
+                    "OAuth account already exists: %s:%s",
+                    obj_in.provider,
+                    obj_in.provider_user_id,
+                )
+                raise DuplicateEntryError(
+                    f"This {obj_in.provider} account is already linked to another user"
+                )
+            logger.error("Integrity error creating OAuth account: %s", error_msg)
+            raise DuplicateEntryError(f"Failed to create OAuth account: {error_msg}")
+        except Exception as e:  # pragma: no cover
+            await db.rollback()
+            logger.exception("Error creating OAuth account: %s", e)
+            raise
+
+    async def delete_account(
+        self,
+        db: AsyncSession,
+        *,
+        user_id: str | UUID,
+        provider: str,
+    ) -> bool:
+        """Delete an OAuth account link."""
+        try:
+            user_uuid = UUID(str(user_id)) if isinstance(user_id, str) else user_id
+
+            result = await db.execute(
+                delete(OAuthAccount).where(
+                    and_(
+                        OAuthAccount.user_id == user_uuid,
+                        OAuthAccount.provider == provider,
+                    )
+                )
+            )
+            await db.commit()
+
+            deleted = result.rowcount > 0
+            if deleted:
+                logger.info(
+                    "OAuth account deleted: %s unlinked from user %s", provider, user_id
+                )
+            else:
+                logger.warning(
+                    "OAuth account not found for deletion: %s for user %s",
+                    provider,
+                    user_id,
+                )
+
+            return deleted
+        except Exception as e:  # pragma: no cover
+            await db.rollback()
+            logger.error(
+                "Error deleting OAuth account %s for user %s: %s", provider, user_id, e
+            )
+            raise
+
+    async def update_tokens(
+        self,
+        db: AsyncSession,
+        *,
+        account: OAuthAccount,
+        access_token: str | None = None,
+        refresh_token: str | None = None,
+        token_expires_at: datetime | None = None,
+    ) -> OAuthAccount:
+        """Update OAuth tokens for an account."""
+        try:
+            if access_token is not None:
+                account.access_token = access_token
+            if refresh_token is not None:
+                account.refresh_token = refresh_token
+            if token_expires_at is not None:
+                account.token_expires_at = token_expires_at
+
+            db.add(account)
+            await db.commit()
+            await db.refresh(account)
+
+            return account
+        except Exception as e:  # pragma: no cover
+            await db.rollback()
+            logger.error("Error updating OAuth tokens: %s", e)
+            raise
+
+
+# Singleton instance
+oauth_account_repo = OAuthAccountRepository(OAuthAccount)

backend/app/repositories/oauth_authorization_code.py

@@ -0,0 +1,108 @@
+# app/repositories/oauth_authorization_code.py
+"""Repository for OAuthAuthorizationCode model."""
+
+import logging
+from datetime import UTC, datetime
+from uuid import UUID
+
+from sqlalchemy import and_, delete, select, update
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.models.oauth_authorization_code import OAuthAuthorizationCode
+
+logger = logging.getLogger(__name__)
+
+
+class OAuthAuthorizationCodeRepository:
+    """Repository for OAuth 2.0 authorization codes."""
+
+    async def create_code(
+        self,
+        db: AsyncSession,
+        *,
+        code: str,
+        client_id: str,
+        user_id: UUID,
+        redirect_uri: str,
+        scope: str,
+        expires_at: datetime,
+        code_challenge: str | None = None,
+        code_challenge_method: str | None = None,
+        state: str | None = None,
+        nonce: str | None = None,
+    ) -> OAuthAuthorizationCode:
+        """Create and persist a new authorization code."""
+        auth_code = OAuthAuthorizationCode(
+            code=code,
+            client_id=client_id,
+            user_id=user_id,
+            redirect_uri=redirect_uri,
+            scope=scope,
+            code_challenge=code_challenge,
+            code_challenge_method=code_challenge_method,
+            state=state,
+            nonce=nonce,
+            expires_at=expires_at,
+            used=False,
+        )
+        db.add(auth_code)
+        await db.commit()
+        return auth_code
+
+    async def consume_code_atomically(
+        self, db: AsyncSession, *, code: str
+    ) -> UUID | None:
+        """
+        Atomically mark a code as used and return its UUID.
+
+        Returns the UUID if the code was found and not yet used, None otherwise.
+        This prevents race conditions per RFC 6749 Section 4.1.2.
+        """
+        stmt = (
+            update(OAuthAuthorizationCode)
+            .where(
+                and_(
+                    OAuthAuthorizationCode.code == code,
+                    OAuthAuthorizationCode.used == False,  # noqa: E712
+                )
+            )
+            .values(used=True)
+            .returning(OAuthAuthorizationCode.id)
+        )
+        result = await db.execute(stmt)
+        row_id = result.scalar_one_or_none()
+        if row_id is not None:
+            await db.commit()
+        return row_id
+
+    async def get_by_id(
+        self, db: AsyncSession, *, code_id: UUID
+    ) -> OAuthAuthorizationCode | None:
+        """Get authorization code by its UUID primary key."""
+        result = await db.execute(
+            select(OAuthAuthorizationCode).where(OAuthAuthorizationCode.id == code_id)
+        )
+        return result.scalar_one_or_none()
+
+    async def get_by_code(
+        self, db: AsyncSession, *, code: str
+    ) -> OAuthAuthorizationCode | None:
+        """Get authorization code by the code string value."""
+        result = await db.execute(
+            select(OAuthAuthorizationCode).where(OAuthAuthorizationCode.code == code)
+        )
+        return result.scalar_one_or_none()
+
+    async def cleanup_expired(self, db: AsyncSession) -> int:
+        """Delete all expired authorization codes. Returns count deleted."""
+        result = await db.execute(
+            delete(OAuthAuthorizationCode).where(
+                OAuthAuthorizationCode.expires_at < datetime.now(UTC)
+            )
+        )
+        await db.commit()
+        return result.rowcount  # type: ignore[attr-defined]
+
+
+# Singleton instance
+oauth_authorization_code_repo = OAuthAuthorizationCodeRepository()

backend/app/repositories/oauth_client.py

@@ -0,0 +1,201 @@
+# app/repositories/oauth_client.py
+"""Repository for OAuthClient model async database operations."""
+
+import logging
+import secrets
+from uuid import UUID
+
+from pydantic import BaseModel
+from sqlalchemy import and_, delete, select
+from sqlalchemy.exc import IntegrityError
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.repository_exceptions import DuplicateEntryError
+from app.models.oauth_client import OAuthClient
+from app.repositories.base import BaseRepository
+from app.schemas.oauth import OAuthClientCreate
+
+logger = logging.getLogger(__name__)
+
+
+class EmptySchema(BaseModel):
+    """Placeholder schema for repository operations that don't need update schemas."""
+
+
+class OAuthClientRepository(
+    BaseRepository[OAuthClient, OAuthClientCreate, EmptySchema]
+):
+    """Repository for OAuth clients (provider mode)."""
+
+    async def get_by_client_id(
+        self, db: AsyncSession, *, client_id: str
+    ) -> OAuthClient | None:
+        """Get OAuth client by client_id."""
+        try:
+            result = await db.execute(
+                select(OAuthClient).where(
+                    and_(
+                        OAuthClient.client_id == client_id,
+                        OAuthClient.is_active == True,  # noqa: E712
+                    )
+                )
+            )
+            return result.scalar_one_or_none()
+        except Exception as e:  # pragma: no cover
+            logger.error("Error getting OAuth client %s: %s", client_id, e)
+            raise
+
+    async def create_client(
+        self,
+        db: AsyncSession,
+        *,
+        obj_in: OAuthClientCreate,
+        owner_user_id: UUID | None = None,
+    ) -> tuple[OAuthClient, str | None]:
+        """Create a new OAuth client."""
+        try:
+            client_id = secrets.token_urlsafe(32)
+
+            client_secret = None
+            client_secret_hash = None
+            if obj_in.client_type == "confidential":
+                client_secret = secrets.token_urlsafe(48)
+                from app.core.auth import get_password_hash
+
+                client_secret_hash = get_password_hash(client_secret)
+
+            db_obj = OAuthClient(
+                client_id=client_id,
+                client_secret_hash=client_secret_hash,
+                client_name=obj_in.client_name,
+                client_description=obj_in.client_description,
+                client_type=obj_in.client_type,
+                redirect_uris=obj_in.redirect_uris,
+                allowed_scopes=obj_in.allowed_scopes,
+                owner_user_id=owner_user_id,
+                is_active=True,
+            )
+            db.add(db_obj)
+            await db.commit()
+            await db.refresh(db_obj)
+
+            logger.info(
+                "OAuth client created: %s (%s...)", obj_in.client_name, client_id[:8]
+            )
+            return db_obj, client_secret
+        except IntegrityError as e:  # pragma: no cover
+            await db.rollback()
+            error_msg = str(e.orig) if hasattr(e, "orig") else str(e)
+            logger.error("Error creating OAuth client: %s", error_msg)
+            raise DuplicateEntryError(f"Failed to create OAuth client: {error_msg}")
+        except Exception as e:  # pragma: no cover
+            await db.rollback()
+            logger.exception("Error creating OAuth client: %s", e)
+            raise
+
+    async def deactivate_client(
+        self, db: AsyncSession, *, client_id: str
+    ) -> OAuthClient | None:
+        """Deactivate an OAuth client."""
+        try:
+            client = await self.get_by_client_id(db, client_id=client_id)
+            if client is None:
+                return None
+
+            client.is_active = False
+            db.add(client)
+            await db.commit()
+            await db.refresh(client)
+
+            logger.info("OAuth client deactivated: %s", client.client_name)
+            return client
+        except Exception as e:  # pragma: no cover
+            await db.rollback()
+            logger.error("Error deactivating OAuth client %s: %s", client_id, e)
+            raise
+
+    async def validate_redirect_uri(
+        self, db: AsyncSession, *, client_id: str, redirect_uri: str
+    ) -> bool:
+        """Validate that a redirect URI is allowed for a client."""
+        try:
+            client = await self.get_by_client_id(db, client_id=client_id)
+            if client is None:
+                return False
+
+            return redirect_uri in (client.redirect_uris or [])
+        except Exception as e:  # pragma: no cover
+            logger.error("Error validating redirect URI: %s", e)
+            return False
+
+    async def verify_client_secret(
+        self, db: AsyncSession, *, client_id: str, client_secret: str
+    ) -> bool:
+        """Verify client credentials."""
+        try:
+            result = await db.execute(
+                select(OAuthClient).where(
+                    and_(
+                        OAuthClient.client_id == client_id,
+                        OAuthClient.is_active == True,  # noqa: E712
+                    )
+                )
+            )
+            client = result.scalar_one_or_none()
+
+            if client is None or client.client_secret_hash is None:
+                return False
+
+            from app.core.auth import verify_password
+
+            stored_hash: str = str(client.client_secret_hash)
+
+            if stored_hash.startswith("$2"):
+                return verify_password(client_secret, stored_hash)
+            else:
+                import hashlib
+
+                secret_hash = hashlib.sha256(client_secret.encode()).hexdigest()
+                return secrets.compare_digest(stored_hash, secret_hash)
+        except Exception as e:  # pragma: no cover
+            logger.error("Error verifying client secret: %s", e)
+            return False
+
+    async def get_all_clients(
+        self, db: AsyncSession, *, include_inactive: bool = False
+    ) -> list[OAuthClient]:
+        """Get all OAuth clients."""
+        try:
+            query = select(OAuthClient).order_by(OAuthClient.created_at.desc())
+            if not include_inactive:
+                query = query.where(OAuthClient.is_active == True)  # noqa: E712
+
+            result = await db.execute(query)
+            return list(result.scalars().all())
+        except Exception as e:  # pragma: no cover
+            logger.error("Error getting all OAuth clients: %s", e)
+            raise
+
+    async def delete_client(self, db: AsyncSession, *, client_id: str) -> bool:
+        """Delete an OAuth client permanently."""
+        try:
+            result = await db.execute(
+                delete(OAuthClient).where(OAuthClient.client_id == client_id)
+            )
+            await db.commit()
+
+            deleted = result.rowcount > 0
+            if deleted:
+                logger.info("OAuth client deleted: %s", client_id)
+            else:
+                logger.warning("OAuth client not found for deletion: %s", client_id)
+
+            return deleted
+        except Exception as e:  # pragma: no cover
+            await db.rollback()
+            logger.error("Error deleting OAuth client %s: %s", client_id, e)
+            raise
+
+
+# Singleton instance
+oauth_client_repo = OAuthClientRepository(OAuthClient)

backend/app/repositories/oauth_consent.py

@@ -0,0 +1,113 @@
+# app/repositories/oauth_consent.py
+"""Repository for OAuthConsent model."""
+
+import logging
+from typing import Any
+from uuid import UUID
+
+from sqlalchemy import and_, delete, select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.models.oauth_client import OAuthClient
+from app.models.oauth_provider_token import OAuthConsent
+
+logger = logging.getLogger(__name__)
+
+
+class OAuthConsentRepository:
+    """Repository for OAuth consent records (user grants to clients)."""
+
+    async def get_consent(
+        self, db: AsyncSession, *, user_id: UUID, client_id: str
+    ) -> OAuthConsent | None:
+        """Get the consent record for a user-client pair, or None if not found."""
+        result = await db.execute(
+            select(OAuthConsent).where(
+                and_(
+                    OAuthConsent.user_id == user_id,
+                    OAuthConsent.client_id == client_id,
+                )
+            )
+        )
+        return result.scalar_one_or_none()
+
+    async def grant_consent(
+        self,
+        db: AsyncSession,
+        *,
+        user_id: UUID,
+        client_id: str,
+        scopes: list[str],
+    ) -> OAuthConsent:
+        """
+        Create or update consent for a user-client pair.
+
+        If consent already exists, the new scopes are merged with existing ones.
+        Returns the created or updated consent record.
+        """
+        consent = await self.get_consent(db, user_id=user_id, client_id=client_id)
+
+        if consent:
+            existing = (
+                set(consent.granted_scopes.split()) if consent.granted_scopes else set()
+            )
+            merged = existing | set(scopes)
+            consent.granted_scopes = " ".join(sorted(merged))  # type: ignore[assignment]
+        else:
+            consent = OAuthConsent(
+                user_id=user_id,
+                client_id=client_id,
+                granted_scopes=" ".join(sorted(set(scopes))),
+            )
+            db.add(consent)
+
+        await db.commit()
+        await db.refresh(consent)
+        return consent
+
+    async def get_user_consents_with_clients(
+        self, db: AsyncSession, *, user_id: UUID
+    ) -> list[dict[str, Any]]:
+        """Get all consent records for a user joined with client details."""
+        result = await db.execute(
+            select(OAuthConsent, OAuthClient)
+            .join(OAuthClient, OAuthConsent.client_id == OAuthClient.client_id)
+            .where(OAuthConsent.user_id == user_id)
+        )
+        rows = result.all()
+        return [
+            {
+                "client_id": consent.client_id,
+                "client_name": client.client_name,
+                "client_description": client.client_description,
+                "granted_scopes": consent.granted_scopes.split()
+                if consent.granted_scopes
+                else [],
+                "granted_at": consent.created_at.isoformat(),
+            }
+            for consent, client in rows
+        ]
+
+    async def revoke_consent(
+        self, db: AsyncSession, *, user_id: UUID, client_id: str
+    ) -> bool:
+        """
+        Delete the consent record for a user-client pair.
+
+        Returns True if a record was found and deleted.
+        Note: Callers are responsible for also revoking associated tokens.
+        """
+        result = await db.execute(
+            delete(OAuthConsent).where(
+                and_(
+                    OAuthConsent.user_id == user_id,
+                    OAuthConsent.client_id == client_id,
+                )
+            )
+        )
+        await db.commit()
+        return result.rowcount > 0  # type: ignore[attr-defined]
+
+
+# Singleton instance
+oauth_consent_repo = OAuthConsentRepository()

backend/app/repositories/oauth_provider_token.py

@@ -0,0 +1,142 @@
+# app/repositories/oauth_provider_token.py
+"""Repository for OAuthProviderRefreshToken model."""
+
+import logging
+from datetime import UTC, datetime, timedelta
+from uuid import UUID
+
+from sqlalchemy import and_, delete, select, update
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.models.oauth_provider_token import OAuthProviderRefreshToken
+
+logger = logging.getLogger(__name__)
+
+
+class OAuthProviderTokenRepository:
+    """Repository for OAuth provider refresh tokens."""
+
+    async def create_token(
+        self,
+        db: AsyncSession,
+        *,
+        token_hash: str,
+        jti: str,
+        client_id: str,
+        user_id: UUID,
+        scope: str,
+        expires_at: datetime,
+        device_info: str | None = None,
+        ip_address: str | None = None,
+    ) -> OAuthProviderRefreshToken:
+        """Create and persist a new refresh token record."""
+        token = OAuthProviderRefreshToken(
+            token_hash=token_hash,
+            jti=jti,
+            client_id=client_id,
+            user_id=user_id,
+            scope=scope,
+            expires_at=expires_at,
+            device_info=device_info,
+            ip_address=ip_address,
+        )
+        db.add(token)
+        await db.commit()
+        return token
+
+    async def get_by_token_hash(
+        self, db: AsyncSession, *, token_hash: str
+    ) -> OAuthProviderRefreshToken | None:
+        """Get refresh token record by SHA-256 token hash."""
+        result = await db.execute(
+            select(OAuthProviderRefreshToken).where(
+                OAuthProviderRefreshToken.token_hash == token_hash
+            )
+        )
+        return result.scalar_one_or_none()
+
+    async def get_by_jti(
+        self, db: AsyncSession, *, jti: str
+    ) -> OAuthProviderRefreshToken | None:
+        """Get refresh token record by JWT ID (JTI)."""
+        result = await db.execute(
+            select(OAuthProviderRefreshToken).where(
+                OAuthProviderRefreshToken.jti == jti
+            )
+        )
+        return result.scalar_one_or_none()
+
+    async def revoke(
+        self, db: AsyncSession, *, token: OAuthProviderRefreshToken
+    ) -> None:
+        """Mark a specific token record as revoked."""
+        token.revoked = True  # type: ignore[assignment]
+        token.last_used_at = datetime.now(UTC)  # type: ignore[assignment]
+        await db.commit()
+
+    async def revoke_all_for_user_client(
+        self, db: AsyncSession, *, user_id: UUID, client_id: str
+    ) -> int:
+        """
+        Revoke all active tokens for a specific user-client pair.
+
+        Used when security incidents are detected (e.g., authorization code reuse).
+        Returns the number of tokens revoked.
+        """
+        result = await db.execute(
+            update(OAuthProviderRefreshToken)
+            .where(
+                and_(
+                    OAuthProviderRefreshToken.user_id == user_id,
+                    OAuthProviderRefreshToken.client_id == client_id,
+                    OAuthProviderRefreshToken.revoked == False,  # noqa: E712
+                )
+            )
+            .values(revoked=True)
+        )
+        count = result.rowcount  # type: ignore[attr-defined]
+        if count > 0:
+            await db.commit()
+        return count
+
+    async def revoke_all_for_user(self, db: AsyncSession, *, user_id: UUID) -> int:
+        """
+        Revoke all active tokens for a user across all clients.
+
+        Used when user changes password or logs out everywhere.
+        Returns the number of tokens revoked.
+        """
+        result = await db.execute(
+            update(OAuthProviderRefreshToken)
+            .where(
+                and_(
+                    OAuthProviderRefreshToken.user_id == user_id,
+                    OAuthProviderRefreshToken.revoked == False,  # noqa: E712
+                )
+            )
+            .values(revoked=True)
+        )
+        count = result.rowcount  # type: ignore[attr-defined]
+        if count > 0:
+            await db.commit()
+        return count
+
+    async def cleanup_expired(self, db: AsyncSession, *, cutoff_days: int = 7) -> int:
+        """
+        Delete expired refresh tokens older than cutoff_days.
+
+        Should be called periodically (e.g., daily).
+        Returns the number of tokens deleted.
+        """
+        cutoff = datetime.now(UTC) - timedelta(days=cutoff_days)
+        result = await db.execute(
+            delete(OAuthProviderRefreshToken).where(
+                OAuthProviderRefreshToken.expires_at < cutoff
+            )
+        )
+        await db.commit()
+        return result.rowcount  # type: ignore[attr-defined]
+
+
+# Singleton instance
+oauth_provider_token_repo = OAuthProviderTokenRepository()

backend/app/repositories/oauth_state.py

@@ -0,0 +1,113 @@
+# app/repositories/oauth_state.py
+"""Repository for OAuthState model async database operations."""
+
+import logging
+from datetime import UTC, datetime
+
+from pydantic import BaseModel
+from sqlalchemy import delete, select
+from sqlalchemy.exc import IntegrityError
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.repository_exceptions import DuplicateEntryError
+from app.models.oauth_state import OAuthState
+from app.repositories.base import BaseRepository
+from app.schemas.oauth import OAuthStateCreate
+
+logger = logging.getLogger(__name__)
+
+
+class EmptySchema(BaseModel):
+    """Placeholder schema for repository operations that don't need update schemas."""
+
+
+class OAuthStateRepository(BaseRepository[OAuthState, OAuthStateCreate, EmptySchema]):
+    """Repository for OAuth state (CSRF protection)."""
+
+    async def create_state(
+        self, db: AsyncSession, *, obj_in: OAuthStateCreate
+    ) -> OAuthState:
+        """Create a new OAuth state for CSRF protection."""
+        try:
+            db_obj = OAuthState(
+                state=obj_in.state,
+                code_verifier=obj_in.code_verifier,
+                nonce=obj_in.nonce,
+                provider=obj_in.provider,
+                redirect_uri=obj_in.redirect_uri,
+                user_id=obj_in.user_id,
+                expires_at=obj_in.expires_at,
+            )
+            db.add(db_obj)
+            await db.commit()
+            await db.refresh(db_obj)
+
+            logger.debug("OAuth state created for %s", obj_in.provider)
+            return db_obj
+        except IntegrityError as e:  # pragma: no cover
+            await db.rollback()
+            error_msg = str(e.orig) if hasattr(e, "orig") else str(e)
+            logger.error("OAuth state collision: %s", error_msg)
+            raise DuplicateEntryError("Failed to create OAuth state, please retry")
+        except Exception as e:  # pragma: no cover
+            await db.rollback()
+            logger.exception("Error creating OAuth state: %s", e)
+            raise
+
+    async def get_and_consume_state(
+        self, db: AsyncSession, *, state: str
+    ) -> OAuthState | None:
+        """Get and delete OAuth state (consume it)."""
+        try:
+            result = await db.execute(
+                select(OAuthState).where(OAuthState.state == state)
+            )
+            db_obj = result.scalar_one_or_none()
+
+            if db_obj is None:
+                logger.warning("OAuth state not found: %s...", state[:8])
+                return None
+
+            now = datetime.now(UTC)
+            expires_at = db_obj.expires_at
+            if expires_at.tzinfo is None:
+                expires_at = expires_at.replace(tzinfo=UTC)
+
+            if expires_at < now:
+                logger.warning("OAuth state expired: %s...", state[:8])
+                await db.delete(db_obj)
+                await db.commit()
+                return None
+
+            await db.delete(db_obj)
+            await db.commit()
+
+            logger.debug("OAuth state consumed: %s...", state[:8])
+            return db_obj
+        except Exception as e:  # pragma: no cover
+            await db.rollback()
+            logger.error("Error consuming OAuth state: %s", e)
+            raise
+
+    async def cleanup_expired(self, db: AsyncSession) -> int:
+        """Clean up expired OAuth states."""
+        try:
+            now = datetime.now(UTC)
+
+            stmt = delete(OAuthState).where(OAuthState.expires_at < now)
+            result = await db.execute(stmt)
+            await db.commit()
+
+            count = result.rowcount
+            if count > 0:
+                logger.info("Cleaned up %s expired OAuth states", count)
+
+            return count
+        except Exception as e:  # pragma: no cover
+            await db.rollback()
+            logger.error("Error cleaning up expired OAuth states: %s", e)
+            raise
+
+
+# Singleton instance
+oauth_state_repo = OAuthStateRepository(OAuthState)

backend/app/repositories/organization.py

@@ -1,17 +1,19 @@
-# app/crud/organization_async.py
-"""Async CRUD operations for Organization model using SQLAlchemy 2.0 patterns."""
+# app/repositories/organization.py
+"""Repository for Organization model async database operations using SQLAlchemy 2.0 patterns."""
+
 import logging
-from typing import Optional, List, Dict, Any
+from typing import Any
 from uuid import UUID
 
-from sqlalchemy import func, or_, and_, select, case
+from sqlalchemy import and_, case, func, or_, select
 from sqlalchemy.exc import IntegrityError
 from sqlalchemy.ext.asyncio import AsyncSession
 
-from app.crud.base import CRUDBase
+from app.core.repository_exceptions import DuplicateEntryError, IntegrityConstraintError
 from app.models.organization import Organization
 from app.models.user import User
-from app.models.user_organization import UserOrganization, OrganizationRole
+from app.models.user_organization import OrganizationRole, UserOrganization
+from app.repositories.base import BaseRepository
 from app.schemas.organizations import (
     OrganizationCreate,
     OrganizationUpdate,
@@ -20,10 +22,12 @@ from app.schemas.organizations import (
 logger = logging.getLogger(__name__)
 
 
-class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUpdate]):
-    """Async CRUD operations for Organization model."""
+class OrganizationRepository(
+    BaseRepository[Organization, OrganizationCreate, OrganizationUpdate]
+):
+    """Repository for Organization model."""
 
-    async def get_by_slug(self, db: AsyncSession, *, slug: str) -> Optional[Organization]:
+    async def get_by_slug(self, db: AsyncSession, *, slug: str) -> Organization | None:
         """Get organization by slug."""
         try:
             result = await db.execute(
@@ -31,10 +35,12 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
             )
             return result.scalar_one_or_none()
         except Exception as e:
-            logger.error(f"Error getting organization by slug {slug}: {str(e)}")
+            logger.error("Error getting organization by slug %s: %s", slug, e)
             raise
 
-    async def create(self, db: AsyncSession, *, obj_in: OrganizationCreate) -> Organization:
+    async def create(
+        self, db: AsyncSession, *, obj_in: OrganizationCreate
+    ) -> Organization:
         """Create a new organization with error handling."""
         try:
             db_obj = Organization(
@@ -42,7 +48,7 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
                 slug=obj_in.slug,
                 description=obj_in.description,
                 is_active=obj_in.is_active,
-                settings=obj_in.settings or {}
+                settings=obj_in.settings or {},
             )
             db.add(db_obj)
             await db.commit()
@@ -50,15 +56,21 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
             return db_obj
         except IntegrityError as e:
             await db.rollback()
-            error_msg = str(e.orig) if hasattr(e, 'orig') else str(e)
-            if "slug" in error_msg.lower():
-                logger.warning(f"Duplicate slug attempted: {obj_in.slug}")
-                raise ValueError(f"Organization with slug '{obj_in.slug}' already exists")
-            logger.error(f"Integrity error creating organization: {error_msg}")
-            raise ValueError(f"Database integrity error: {error_msg}")
+            error_msg = str(e.orig) if hasattr(e, "orig") else str(e)
+            if (
+                "slug" in error_msg.lower()
+                or "unique" in error_msg.lower()
+                or "duplicate" in error_msg.lower()
+            ):
+                logger.warning("Duplicate slug attempted: %s", obj_in.slug)
+                raise DuplicateEntryError(
+                    f"Organization with slug '{obj_in.slug}' already exists"
+                )
+            logger.error("Integrity error creating organization: %s", error_msg)
+            raise IntegrityConstraintError(f"Database integrity error: {error_msg}")
         except Exception as e:
             await db.rollback()
-            logger.error(f"Unexpected error creating organization: {str(e)}", exc_info=True)
+            logger.exception("Unexpected error creating organization: %s", e)
             raise
 
     async def get_multi_with_filters(
@@ -67,21 +79,15 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
         *,
         skip: int = 0,
         limit: int = 100,
-        is_active: Optional[bool] = None,
-        search: Optional[str] = None,
+        is_active: bool | None = None,
+        search: str | None = None,
         sort_by: str = "created_at",
-        sort_order: str = "desc"
-    ) -> tuple[List[Organization], int]:
-        """
-        Get multiple organizations with filtering, searching, and sorting.
-
-        Returns:
-            Tuple of (organizations list, total count)
-        """
+        sort_order: str = "desc",
+    ) -> tuple[list[Organization], int]:
+        """Get multiple organizations with filtering, searching, and sorting."""
         try:
             query = select(Organization)
 
-            # Apply filters
             if is_active is not None:
                 query = query.where(Organization.is_active == is_active)
 
@@ -89,30 +95,27 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
                 search_filter = or_(
                     Organization.name.ilike(f"%{search}%"),
                     Organization.slug.ilike(f"%{search}%"),
-                    Organization.description.ilike(f"%{search}%")
+                    Organization.description.ilike(f"%{search}%"),
                 )
                 query = query.where(search_filter)
 
-            # Get total count before pagination
             count_query = select(func.count()).select_from(query.alias())
             count_result = await db.execute(count_query)
             total = count_result.scalar_one()
 
-            # Apply sorting
             sort_column = getattr(Organization, sort_by, Organization.created_at)
             if sort_order == "desc":
                 query = query.order_by(sort_column.desc())
             else:
                 query = query.order_by(sort_column.asc())
 
-            # Apply pagination
             query = query.offset(skip).limit(limit)
             result = await db.execute(query)
             organizations = list(result.scalars().all())
 
             return organizations, total
         except Exception as e:
-            logger.error(f"Error getting organizations with filters: {str(e)}")
+            logger.error("Error getting organizations with filters: %s", e)
             raise
 
     async def get_member_count(self, db: AsyncSession, *, organization_id: UUID) -> int:
@@ -122,13 +125,15 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
                 select(func.count(UserOrganization.user_id)).where(
                     and_(
                         UserOrganization.organization_id == organization_id,
-                        UserOrganization.is_active == True
+                        UserOrganization.is_active,
                     )
                 )
             )
             return result.scalar_one() or 0
         except Exception as e:
-            logger.error(f"Error getting member count for organization {organization_id}: {str(e)}")
+            logger.error(
+                "Error getting member count for organization %s: %s", organization_id, e
+            )
             raise
 
     async def get_multi_with_member_counts(
@@ -137,76 +142,70 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
         *,
         skip: int = 0,
         limit: int = 100,
-        is_active: Optional[bool] = None,
-        search: Optional[str] = None
-    ) -> tuple[List[Dict[str, Any]], int]:
-        """
-        Get organizations with member counts in a SINGLE QUERY using JOIN and GROUP BY.
-        This eliminates the N+1 query problem.
-
-        Returns:
-            Tuple of (list of dicts with org and member_count, total count)
-        """
+        is_active: bool | None = None,
+        search: str | None = None,
+    ) -> tuple[list[dict[str, Any]], int]:
+        """Get organizations with member counts in a SINGLE QUERY using JOIN and GROUP BY."""
         try:
-            # Build base query with LEFT JOIN and GROUP BY
-            # Use CASE statement to count only active members
             query = (
                 select(
                     Organization,
                     func.count(
                         func.distinct(
                             case(
-                                (UserOrganization.is_active == True, UserOrganization.user_id),
-                                else_=None
+                                (
+                                    UserOrganization.is_active,
+                                    UserOrganization.user_id,
+                                ),
+                                else_=None,
                             )
                         )
-                    ).label('member_count')
+                    ).label("member_count"),
+                )
+                .outerjoin(
+                    UserOrganization,
+                    Organization.id == UserOrganization.organization_id,
                 )
-                .outerjoin(UserOrganization, Organization.id == UserOrganization.organization_id)
                 .group_by(Organization.id)
             )
 
-            # Apply filters
             if is_active is not None:
                 query = query.where(Organization.is_active == is_active)
 
+            search_filter = None
             if search:
                 search_filter = or_(
                     Organization.name.ilike(f"%{search}%"),
                     Organization.slug.ilike(f"%{search}%"),
-                    Organization.description.ilike(f"%{search}%")
+                    Organization.description.ilike(f"%{search}%"),
                 )
                 query = query.where(search_filter)
 
-            # Get total count
             count_query = select(func.count(Organization.id))
             if is_active is not None:
                 count_query = count_query.where(Organization.is_active == is_active)
-            if search:
+            if search_filter is not None:
                 count_query = count_query.where(search_filter)
 
             count_result = await db.execute(count_query)
             total = count_result.scalar_one()
 
-            # Apply pagination and ordering
-            query = query.order_by(Organization.created_at.desc()).offset(skip).limit(limit)
+            query = (
+                query.order_by(Organization.created_at.desc()).offset(skip).limit(limit)
+            )
 
             result = await db.execute(query)
             rows = result.all()
 
-            # Convert to list of dicts
             orgs_with_counts = [
-                {
-                    'organization': org,
-                    'member_count': member_count
-                }
+                {"organization": org, "member_count": member_count}
                 for org, member_count in rows
             ]
 
             return orgs_with_counts, total
 
         except Exception as e:
-            logger.error(f"Error getting organizations with member counts: {str(e)}", exc_info=True)
+            logger.exception("Error getting organizations with member counts: %s", e)
             raise
 
     async def add_user(
@@ -216,23 +215,21 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
         organization_id: UUID,
         user_id: UUID,
         role: OrganizationRole = OrganizationRole.MEMBER,
-        custom_permissions: Optional[str] = None
+        custom_permissions: str | None = None,
     ) -> UserOrganization:
         """Add a user to an organization with a specific role."""
         try:
-            # Check if relationship already exists
             result = await db.execute(
                 select(UserOrganization).where(
                     and_(
                         UserOrganization.user_id == user_id,
-                        UserOrganization.organization_id == organization_id
+                        UserOrganization.organization_id == organization_id,
                     )
                 )
             )
             existing = result.scalar_one_or_none()
 
             if existing:
-                # Reactivate if inactive, or raise error if already active
                 if not existing.is_active:
                     existing.is_active = True
                     existing.role = role
@@ -241,15 +238,16 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
                     await db.refresh(existing)
                     return existing
                 else:
-                    raise ValueError("User is already a member of this organization")
+                    raise DuplicateEntryError(
+                        "User is already a member of this organization"
+                    )
 
-            # Create new relationship
             user_org = UserOrganization(
                 user_id=user_id,
                 organization_id=organization_id,
                 role=role,
                 is_active=True,
-                custom_permissions=custom_permissions
+                custom_permissions=custom_permissions,
             )
             db.add(user_org)
             await db.commit()
@@ -257,19 +255,15 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
             return user_org
         except IntegrityError as e:
             await db.rollback()
-            logger.error(f"Integrity error adding user to organization: {str(e)}")
-            raise ValueError("Failed to add user to organization")
+            logger.error("Integrity error adding user to organization: %s", e)
+            raise IntegrityConstraintError("Failed to add user to organization")
         except Exception as e:
             await db.rollback()
-            logger.error(f"Error adding user to organization: {str(e)}", exc_info=True)
+            logger.exception("Error adding user to organization: %s", e)
             raise
 
     async def remove_user(
-        self,
-        db: AsyncSession,
-        *,
-        organization_id: UUID,
-        user_id: UUID
+        self, db: AsyncSession, *, organization_id: UUID, user_id: UUID
     ) -> bool:
         """Remove a user from an organization (soft delete)."""
         try:
@@ -277,7 +271,7 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
                 select(UserOrganization).where(
                     and_(
                         UserOrganization.user_id == user_id,
-                        UserOrganization.organization_id == organization_id
+                        UserOrganization.organization_id == organization_id,
                     )
                 )
             )
@@ -291,7 +285,7 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
             return True
         except Exception as e:
             await db.rollback()
-            logger.error(f"Error removing user from organization: {str(e)}", exc_info=True)
+            logger.exception("Error removing user from organization: %s", e)
             raise
 
     async def update_user_role(
@@ -301,15 +295,15 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
         organization_id: UUID,
         user_id: UUID,
         role: OrganizationRole,
-        custom_permissions: Optional[str] = None
-    ) -> Optional[UserOrganization]:
+        custom_permissions: str | None = None,
+    ) -> UserOrganization | None:
         """Update a user's role in an organization."""
         try:
             result = await db.execute(
                 select(UserOrganization).where(
                     and_(
                         UserOrganization.user_id == user_id,
-                        UserOrganization.organization_id == organization_id
+                        UserOrganization.organization_id == organization_id,
                     )
                 )
             )
@@ -326,7 +320,7 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
             return user_org
         except Exception as e:
             await db.rollback()
-            logger.error(f"Error updating user role: {str(e)}", exc_info=True)
+            logger.exception("Error updating user role: %s", e)
             raise
 
     async def get_organization_members(
@@ -336,16 +330,10 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
         organization_id: UUID,
         skip: int = 0,
         limit: int = 100,
-        is_active: bool = True
-    ) -> tuple[List[Dict[str, Any]], int]:
-        """
-        Get members of an organization with user details.
-
-        Returns:
-            Tuple of (members list with user details, total count)
-        """
+        is_active: bool | None = True,
+    ) -> tuple[list[dict[str, Any]], int]:
+        """Get members of an organization with user details."""
         try:
-            # Build query with join
             query = (
                 select(UserOrganization, User)
                 .join(User, UserOrganization.user_id == User.id)
@@ -355,50 +343,57 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
             if is_active is not None:
                 query = query.where(UserOrganization.is_active == is_active)
 
-            # Get total count
             count_query = select(func.count()).select_from(
                 select(UserOrganization)
                 .where(UserOrganization.organization_id == organization_id)
-                .where(UserOrganization.is_active == is_active if is_active is not None else True)
+                .where(
+                    UserOrganization.is_active == is_active
+                    if is_active is not None
+                    else True
+                )
                 .alias()
             )
             count_result = await db.execute(count_query)
             total = count_result.scalar_one()
 
-            # Apply ordering and pagination
-            query = query.order_by(UserOrganization.created_at.desc()).offset(skip).limit(limit)
+            query = (
+                query.order_by(UserOrganization.created_at.desc())
+                .offset(skip)
+                .limit(limit)
+            )
             result = await db.execute(query)
             results = result.all()
 
             members = []
             for user_org, user in results:
-                members.append({
-                    "user_id": user.id,
-                    "email": user.email,
-                    "first_name": user.first_name,
-                    "last_name": user.last_name,
-                    "role": user_org.role,
-                    "is_active": user_org.is_active,
-                    "joined_at": user_org.created_at
-                })
+                members.append(
+                    {
+                        "user_id": user.id,
+                        "email": user.email,
+                        "first_name": user.first_name,
+                        "last_name": user.last_name,
+                        "role": user_org.role,
+                        "is_active": user_org.is_active,
+                        "joined_at": user_org.created_at,
+                    }
+                )
 
             return members, total
         except Exception as e:
-            logger.error(f"Error getting organization members: {str(e)}")
+            logger.error("Error getting organization members: %s", e)
             raise
 
     async def get_user_organizations(
-        self,
-        db: AsyncSession,
-        *,
-        user_id: UUID,
-        is_active: bool = True
-    ) -> List[Organization]:
+        self, db: AsyncSession, *, user_id: UUID, is_active: bool | None = True
+    ) -> list[Organization]:
         """Get all organizations a user belongs to."""
         try:
             query = (
                 select(Organization)
-                .join(UserOrganization, Organization.id == UserOrganization.organization_id)
+                .join(
+                    UserOrganization,
+                    Organization.id == UserOrganization.organization_id,
+                )
                 .where(UserOrganization.user_id == user_id)
             )
 
@@ -408,44 +403,40 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
             result = await db.execute(query)
             return list(result.scalars().all())
         except Exception as e:
-            logger.error(f"Error getting user organizations: {str(e)}")
+            logger.error("Error getting user organizations: %s", e)
             raise
 
     async def get_user_organizations_with_details(
-        self,
-        db: AsyncSession,
-        *,
-        user_id: UUID,
-        is_active: bool = True
-    ) -> List[Dict[str, Any]]:
-        """
-        Get user's organizations with role and member count in SINGLE QUERY.
-        Eliminates N+1 problem by using subquery for member counts.
-
-        Returns:
-            List of dicts with organization, role, and member_count
-        """
+        self, db: AsyncSession, *, user_id: UUID, is_active: bool | None = True
+    ) -> list[dict[str, Any]]:
+        """Get user's organizations with role and member count in SINGLE QUERY."""
         try:
-            # Subquery to get member counts for each organization
             member_count_subq = (
                 select(
                     UserOrganization.organization_id,
-                    func.count(UserOrganization.user_id).label('member_count')
+                    func.count(UserOrganization.user_id).label("member_count"),
                 )
-                .where(UserOrganization.is_active == True)
+                .where(UserOrganization.is_active)
                 .group_by(UserOrganization.organization_id)
                 .subquery()
             )
 
-            # Main query with JOIN to get org, role, and member count
             query = (
                 select(
                     Organization,
                     UserOrganization.role,
-                    func.coalesce(member_count_subq.c.member_count, 0).label('member_count')
+                    func.coalesce(member_count_subq.c.member_count, 0).label(
+                        "member_count"
+                    ),
+                )
+                .join(
+                    UserOrganization,
+                    Organization.id == UserOrganization.organization_id,
+                )
+                .outerjoin(
+                    member_count_subq,
+                    Organization.id == member_count_subq.c.organization_id,
                 )
-                .join(UserOrganization, Organization.id == UserOrganization.organization_id)
-                .outerjoin(member_count_subq, Organization.id == member_count_subq.c.organization_id)
                 .where(UserOrganization.user_id == user_id)
             )
 
@@ -456,25 +447,17 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
             rows = result.all()
 
             return [
-                {
-                    'organization': org,
-                    'role': role,
-                    'member_count': member_count
-                }
+                {"organization": org, "role": role, "member_count": member_count}
                 for org, role, member_count in rows
             ]
 
         except Exception as e:
-            logger.error(f"Error getting user organizations with details: {str(e)}", exc_info=True)
+            logger.exception("Error getting user organizations with details: %s", e)
             raise
 
     async def get_user_role_in_org(
-        self,
-        db: AsyncSession,
-        *,
-        user_id: UUID,
-        organization_id: UUID
-    ) -> Optional[OrganizationRole]:
+        self, db: AsyncSession, *, user_id: UUID, organization_id: UUID
+    ) -> OrganizationRole | None:
         """Get a user's role in a specific organization."""
         try:
             result = await db.execute(
@@ -482,39 +465,35 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
                     and_(
                         UserOrganization.user_id == user_id,
                         UserOrganization.organization_id == organization_id,
-                        UserOrganization.is_active == True
+                        UserOrganization.is_active,
                     )
                 )
             )
             user_org = result.scalar_one_or_none()
 
-            return user_org.role if user_org else None
+            return user_org.role if user_org else None  # pyright: ignore[reportReturnType]
         except Exception as e:
-            logger.error(f"Error getting user role in org: {str(e)}")
+            logger.error("Error getting user role in org: %s", e)
             raise
 
     async def is_user_org_owner(
-        self,
-        db: AsyncSession,
-        *,
-        user_id: UUID,
-        organization_id: UUID
+        self, db: AsyncSession, *, user_id: UUID, organization_id: UUID
     ) -> bool:
         """Check if a user is an owner of an organization."""
-        role = await self.get_user_role_in_org(db, user_id=user_id, organization_id=organization_id)
+        role = await self.get_user_role_in_org(
+            db, user_id=user_id, organization_id=organization_id
+        )
         return role == OrganizationRole.OWNER
 
     async def is_user_org_admin(
-        self,
-        db: AsyncSession,
-        *,
-        user_id: UUID,
-        organization_id: UUID
+        self, db: AsyncSession, *, user_id: UUID, organization_id: UUID
     ) -> bool:
         """Check if a user is an owner or admin of an organization."""
-        role = await self.get_user_role_in_org(db, user_id=user_id, organization_id=organization_id)
+        role = await self.get_user_role_in_org(
+            db, user_id=user_id, organization_id=organization_id
+        )
         return role in [OrganizationRole.OWNER, OrganizationRole.ADMIN]
 
 
-# Create a singleton instance for use across the application
-organization = CRUDOrganization(Organization)
+# Singleton instance
+organization_repo = OrganizationRepository(Organization)

backend/app/repositories/session.py

@@ -0,0 +1,333 @@
+# app/repositories/session.py
+"""Repository for UserSession model async database operations using SQLAlchemy 2.0 patterns."""
+
+import logging
+import uuid
+from datetime import UTC, datetime, timedelta
+from uuid import UUID
+
+from sqlalchemy import and_, delete, func, select, update
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.orm import joinedload
+
+from app.core.repository_exceptions import IntegrityConstraintError, InvalidInputError
+from app.models.user_session import UserSession
+from app.repositories.base import BaseRepository
+from app.schemas.sessions import SessionCreate, SessionUpdate
+
+logger = logging.getLogger(__name__)
+
+
+class SessionRepository(BaseRepository[UserSession, SessionCreate, SessionUpdate]):
+    """Repository for UserSession model."""
+
+    async def get_by_jti(self, db: AsyncSession, *, jti: str) -> UserSession | None:
+        """Get session by refresh token JTI."""
+        try:
+            result = await db.execute(
+                select(UserSession).where(UserSession.refresh_token_jti == jti)
+            )
+            return result.scalar_one_or_none()
+        except Exception as e:
+            logger.error("Error getting session by JTI %s: %s", jti, e)
+            raise
+
+    async def get_active_by_jti(
+        self, db: AsyncSession, *, jti: str
+    ) -> UserSession | None:
+        """Get active session by refresh token JTI."""
+        try:
+            result = await db.execute(
+                select(UserSession).where(
+                    and_(
+                        UserSession.refresh_token_jti == jti,
+                        UserSession.is_active,
+                    )
+                )
+            )
+            return result.scalar_one_or_none()
+        except Exception as e:
+            logger.error("Error getting active session by JTI %s: %s", jti, e)
+            raise
+
+    async def get_user_sessions(
+        self,
+        db: AsyncSession,
+        *,
+        user_id: str,
+        active_only: bool = True,
+        with_user: bool = False,
+    ) -> list[UserSession]:
+        """Get all sessions for a user with optional eager loading."""
+        try:
+            user_uuid = UUID(user_id) if isinstance(user_id, str) else user_id
+
+            query = select(UserSession).where(UserSession.user_id == user_uuid)
+
+            if with_user:
+                query = query.options(joinedload(UserSession.user))
+
+            if active_only:
+                query = query.where(UserSession.is_active)
+
+            query = query.order_by(UserSession.last_used_at.desc())
+            result = await db.execute(query)
+            return list(result.scalars().all())
+        except Exception as e:
+            logger.error("Error getting sessions for user %s: %s", user_id, e)
+            raise
+
+    async def create_session(
+        self, db: AsyncSession, *, obj_in: SessionCreate
+    ) -> UserSession:
+        """Create a new user session."""
+        try:
+            db_obj = UserSession(
+                user_id=obj_in.user_id,
+                refresh_token_jti=obj_in.refresh_token_jti,
+                device_name=obj_in.device_name,
+                device_id=obj_in.device_id,
+                ip_address=obj_in.ip_address,
+                user_agent=obj_in.user_agent,
+                last_used_at=obj_in.last_used_at,
+                expires_at=obj_in.expires_at,
+                is_active=True,
+                location_city=obj_in.location_city,
+                location_country=obj_in.location_country,
+            )
+            db.add(db_obj)
+            await db.commit()
+            await db.refresh(db_obj)
+
+            logger.info(
+                "Session created for user %s from %s (IP: %s)",
+                obj_in.user_id,
+                obj_in.device_name,
+                obj_in.ip_address,
+            )
+
+            return db_obj
+        except Exception as e:
+            await db.rollback()
+            logger.exception("Error creating session: %s", e)
+            raise IntegrityConstraintError(f"Failed to create session: {e!s}")
+
+    async def deactivate(
+        self, db: AsyncSession, *, session_id: str
+    ) -> UserSession | None:
+        """Deactivate a session (logout from device)."""
+        try:
+            session = await self.get(db, id=session_id)
+            if not session:
+                logger.warning("Session %s not found for deactivation", session_id)
+                return None
+
+            session.is_active = False
+            db.add(session)
+            await db.commit()
+            await db.refresh(session)
+
+            logger.info(
+                "Session %s deactivated for user %s (%s)",
+                session_id,
+                session.user_id,
+                session.device_name,
+            )
+
+            return session
+        except Exception as e:
+            await db.rollback()
+            logger.error("Error deactivating session %s: %s", session_id, e)
+            raise
+
+    async def deactivate_all_user_sessions(
+        self, db: AsyncSession, *, user_id: str
+    ) -> int:
+        """Deactivate all active sessions for a user (logout from all devices)."""
+        try:
+            user_uuid = UUID(user_id) if isinstance(user_id, str) else user_id
+
+            stmt = (
+                update(UserSession)
+                .where(and_(UserSession.user_id == user_uuid, UserSession.is_active))
+                .values(is_active=False)
+            )
+
+            result = await db.execute(stmt)
+            await db.commit()
+
+            count = result.rowcount
+
+            logger.info("Deactivated %s sessions for user %s", count, user_id)
+
+            return count
+        except Exception as e:
+            await db.rollback()
+            logger.error("Error deactivating all sessions for user %s: %s", user_id, e)
+            raise
+
+    async def update_last_used(
+        self, db: AsyncSession, *, session: UserSession
+    ) -> UserSession:
+        """Update the last_used_at timestamp for a session."""
+        try:
+            session.last_used_at = datetime.now(UTC)
+            db.add(session)
+            await db.commit()
+            await db.refresh(session)
+            return session
+        except Exception as e:
+            await db.rollback()
+            logger.error("Error updating last_used for session %s: %s", session.id, e)
+            raise
+
+    async def update_refresh_token(
+        self,
+        db: AsyncSession,
+        *,
+        session: UserSession,
+        new_jti: str,
+        new_expires_at: datetime,
+    ) -> UserSession:
+        """Update session with new refresh token JTI and expiration."""
+        try:
+            session.refresh_token_jti = new_jti
+            session.expires_at = new_expires_at
+            session.last_used_at = datetime.now(UTC)
+            db.add(session)
+            await db.commit()
+            await db.refresh(session)
+            return session
+        except Exception as e:
+            await db.rollback()
+            logger.error(
+                "Error updating refresh token for session %s: %s", session.id, e
+            )
+            raise
+
+    async def cleanup_expired(self, db: AsyncSession, *, keep_days: int = 30) -> int:
+        """Clean up expired sessions using optimized bulk DELETE."""
+        try:
+            cutoff_date = datetime.now(UTC) - timedelta(days=keep_days)
+            now = datetime.now(UTC)
+
+            stmt = delete(UserSession).where(
+                and_(
+                    UserSession.is_active == False,  # noqa: E712
+                    UserSession.expires_at < now,
+                    UserSession.created_at < cutoff_date,
+                )
+            )
+
+            result = await db.execute(stmt)
+            await db.commit()
+
+            count = result.rowcount
+
+            if count > 0:
+                logger.info("Cleaned up %s expired sessions using bulk DELETE", count)
+
+            return count
+        except Exception as e:
+            await db.rollback()
+            logger.error("Error cleaning up expired sessions: %s", e)
+            raise
+
+    async def cleanup_expired_for_user(self, db: AsyncSession, *, user_id: str) -> int:
+        """Clean up expired and inactive sessions for a specific user."""
+        try:
+            try:
+                uuid_obj = uuid.UUID(user_id)
+            except (ValueError, AttributeError):
+                logger.error("Invalid UUID format: %s", user_id)
+                raise InvalidInputError(f"Invalid user ID format: {user_id}")
+
+            now = datetime.now(UTC)
+
+            stmt = delete(UserSession).where(
+                and_(
+                    UserSession.user_id == uuid_obj,
+                    UserSession.is_active == False,  # noqa: E712
+                    UserSession.expires_at < now,
+                )
+            )
+
+            result = await db.execute(stmt)
+            await db.commit()
+
+            count = result.rowcount
+
+            if count > 0:
+                logger.info(
+                    "Cleaned up %s expired sessions for user %s using bulk DELETE",
+                    count,
+                    user_id,
+                )
+
+            return count
+        except Exception as e:
+            await db.rollback()
+            logger.error(
+                "Error cleaning up expired sessions for user %s: %s", user_id, e
+            )
+            raise
+
+    async def get_user_session_count(self, db: AsyncSession, *, user_id: str) -> int:
+        """Get count of active sessions for a user."""
+        try:
+            user_uuid = UUID(user_id) if isinstance(user_id, str) else user_id
+
+            result = await db.execute(
+                select(func.count(UserSession.id)).where(
+                    and_(UserSession.user_id == user_uuid, UserSession.is_active)
+                )
+            )
+            return result.scalar_one()
+        except Exception as e:
+            logger.error("Error counting sessions for user %s: %s", user_id, e)
+            raise
+
+    async def get_all_sessions(
+        self,
+        db: AsyncSession,
+        *,
+        skip: int = 0,
+        limit: int = 100,
+        active_only: bool = True,
+        with_user: bool = True,
+    ) -> tuple[list[UserSession], int]:
+        """Get all sessions across all users with pagination (admin only)."""
+        try:
+            query = select(UserSession)
+
+            if with_user:
+                query = query.options(joinedload(UserSession.user))
+
+            if active_only:
+                query = query.where(UserSession.is_active)
+
+            count_query = select(func.count(UserSession.id))
+            if active_only:
+                count_query = count_query.where(UserSession.is_active)
+
+            count_result = await db.execute(count_query)
+            total = count_result.scalar_one()
+
+            query = (
+                query.order_by(UserSession.last_used_at.desc())
+                .offset(skip)
+                .limit(limit)
+            )
+
+            result = await db.execute(query)
+            sessions = list(result.scalars().all())
+
+            return sessions, total
+
+        except Exception as e:
+            logger.exception("Error getting all sessions: %s", e)
+            raise
+
+
+# Singleton instance
+session_repo = SessionRepository(UserSession)

backend/app/repositories/user.py

@@ -1,8 +1,9 @@
-# app/crud/user_async.py
-"""Async CRUD operations for User model using SQLAlchemy 2.0 patterns."""
+# app/repositories/user.py
+"""Repository for User model async database operations using SQLAlchemy 2.0 patterns."""
+
 import logging
-from datetime import datetime, timezone
-from typing import Optional, Union, Dict, Any, List, Tuple
+from datetime import UTC, datetime
+from typing import Any
 from uuid import UUID
 
 from sqlalchemy import or_, select, update
@@ -10,31 +11,29 @@ from sqlalchemy.exc import IntegrityError
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.core.auth import get_password_hash_async
-from app.crud.base import CRUDBase
+from app.core.repository_exceptions import DuplicateEntryError, InvalidInputError
 from app.models.user import User
+from app.repositories.base import BaseRepository
 from app.schemas.users import UserCreate, UserUpdate
 
 logger = logging.getLogger(__name__)
 
 
-class CRUDUser(CRUDBase[User, UserCreate, UserUpdate]):
-    """Async CRUD operations for User model."""
+class UserRepository(BaseRepository[User, UserCreate, UserUpdate]):
+    """Repository for User model."""
 
-    async def get_by_email(self, db: AsyncSession, *, email: str) -> Optional[User]:
+    async def get_by_email(self, db: AsyncSession, *, email: str) -> User | None:
         """Get user by email address."""
         try:
-            result = await db.execute(
-                select(User).where(User.email == email)
-            )
+            result = await db.execute(select(User).where(User.email == email))
             return result.scalar_one_or_none()
         except Exception as e:
-            logger.error(f"Error getting user by email {email}: {str(e)}")
+            logger.error("Error getting user by email %s: %s", email, e)
             raise
 
     async def create(self, db: AsyncSession, *, obj_in: UserCreate) -> User:
         """Create a new user with async password hashing and error handling."""
         try:
-            # Hash password asynchronously to avoid blocking event loop
             password_hash = await get_password_hash_async(obj_in.password)
 
             db_obj = User(
@@ -42,9 +41,13 @@ class CRUDUser(CRUDBase[User, UserCreate, UserUpdate]):
                 password_hash=password_hash,
                 first_name=obj_in.first_name,
                 last_name=obj_in.last_name,
-                phone_number=obj_in.phone_number if hasattr(obj_in, 'phone_number') else None,
-                is_superuser=obj_in.is_superuser if hasattr(obj_in, 'is_superuser') else False,
-                preferences={}
+                phone_number=obj_in.phone_number
+                if hasattr(obj_in, "phone_number")
+                else None,
+                is_superuser=obj_in.is_superuser
+                if hasattr(obj_in, "is_superuser")
+                else False,
+                preferences={},
             )
             db.add(db_obj)
             await db.commit()
@@ -52,23 +55,55 @@ class CRUDUser(CRUDBase[User, UserCreate, UserUpdate]):
             return db_obj
         except IntegrityError as e:
             await db.rollback()
-            error_msg = str(e.orig) if hasattr(e, 'orig') else str(e)
+            error_msg = str(e.orig) if hasattr(e, "orig") else str(e)
             if "email" in error_msg.lower():
-                logger.warning(f"Duplicate email attempted: {obj_in.email}")
-                raise ValueError(f"User with email {obj_in.email} already exists")
-            logger.error(f"Integrity error creating user: {error_msg}")
-            raise ValueError(f"Database integrity error: {error_msg}")
+                logger.warning("Duplicate email attempted: %s", obj_in.email)
+                raise DuplicateEntryError(
+                    f"User with email {obj_in.email} already exists"
+                )
+            logger.error("Integrity error creating user: %s", error_msg)
+            raise DuplicateEntryError(f"Database integrity error: {error_msg}")
         except Exception as e:
             await db.rollback()
-            logger.error(f"Unexpected error creating user: {str(e)}", exc_info=True)
+            logger.exception("Unexpected error creating user: %s", e)
             raise
 
-    async def update(
+    async def create_oauth_user(
         self,
         db: AsyncSession,
         *,
-        db_obj: User,
-        obj_in: Union[UserUpdate, Dict[str, Any]]
+        email: str,
+        first_name: str = "User",
+        last_name: str | None = None,
+    ) -> User:
+        """Create a new passwordless user for OAuth sign-in."""
+        try:
+            db_obj = User(
+                email=email,
+                password_hash=None,  # OAuth-only user
+                first_name=first_name,
+                last_name=last_name,
+                is_active=True,
+                is_superuser=False,
+            )
+            db.add(db_obj)
+            await db.flush()  # Get user.id without committing
+            return db_obj
+        except IntegrityError as e:
+            await db.rollback()
+            error_msg = str(e.orig) if hasattr(e, "orig") else str(e)
+            if "email" in error_msg.lower():
+                logger.warning("Duplicate email attempted: %s", email)
+                raise DuplicateEntryError(f"User with email {email} already exists")
+            logger.error("Integrity error creating OAuth user: %s", error_msg)
+            raise DuplicateEntryError(f"Database integrity error: {error_msg}")
+        except Exception as e:
+            await db.rollback()
+            logger.exception("Unexpected error creating OAuth user: %s", e)
+            raise
+
+    async def update(
+        self, db: AsyncSession, *, db_obj: User, obj_in: UserUpdate | dict[str, Any]
     ) -> User:
         """Update user with async password hashing if password is updated."""
         if isinstance(obj_in, dict):
@@ -76,77 +111,65 @@ class CRUDUser(CRUDBase[User, UserCreate, UserUpdate]):
         else:
             update_data = obj_in.model_dump(exclude_unset=True)
 
-        # Handle password separately if it exists in update data
-        # Hash password asynchronously to avoid blocking event loop
         if "password" in update_data:
-            update_data["password_hash"] = await get_password_hash_async(update_data["password"])
+            update_data["password_hash"] = await get_password_hash_async(
+                update_data["password"]
+            )
             del update_data["password"]
 
         return await super().update(db, db_obj=db_obj, obj_in=update_data)
 
+    async def update_password(
+        self, db: AsyncSession, *, user: User, password_hash: str
+    ) -> User:
+        """Set a new password hash on a user and commit."""
+        user.password_hash = password_hash
+        await db.commit()
+        await db.refresh(user)
+        return user
+
     async def get_multi_with_total(
         self,
         db: AsyncSession,
         *,
         skip: int = 0,
         limit: int = 100,
-        sort_by: Optional[str] = None,
+        sort_by: str | None = None,
         sort_order: str = "asc",
-        filters: Optional[Dict[str, Any]] = None,
-        search: Optional[str] = None
-    ) -> Tuple[List[User], int]:
-        """
-        Get multiple users with total count, filtering, sorting, and search.
-
-        Args:
-            db: Database session
-            skip: Number of records to skip
-            limit: Maximum number of records to return
-            sort_by: Field name to sort by
-            sort_order: Sort order ("asc" or "desc")
-            filters: Dictionary of filters (field_name: value)
-            search: Search term to match against email, first_name, last_name
-
-        Returns:
-            Tuple of (users list, total count)
-        """
-        # Validate pagination
+        filters: dict[str, Any] | None = None,
+        search: str | None = None,
+    ) -> tuple[list[User], int]:
+        """Get multiple users with total count, filtering, sorting, and search."""
         if skip < 0:
-            raise ValueError("skip must be non-negative")
+            raise InvalidInputError("skip must be non-negative")
         if limit < 0:
-            raise ValueError("limit must be non-negative")
+            raise InvalidInputError("limit must be non-negative")
         if limit > 1000:
-            raise ValueError("Maximum limit is 1000")
+            raise InvalidInputError("Maximum limit is 1000")
 
         try:
-            # Build base query
             query = select(User)
-
-            # Exclude soft-deleted users
             query = query.where(User.deleted_at.is_(None))
 
-            # Apply filters
             if filters:
                 for field, value in filters.items():
                     if hasattr(User, field) and value is not None:
                         query = query.where(getattr(User, field) == value)
 
-            # Apply search
             if search:
                 search_filter = or_(
                     User.email.ilike(f"%{search}%"),
                     User.first_name.ilike(f"%{search}%"),
-                    User.last_name.ilike(f"%{search}%")
+                    User.last_name.ilike(f"%{search}%"),
                 )
                 query = query.where(search_filter)
 
-            # Get total count
             from sqlalchemy import func
+
             count_query = select(func.count()).select_from(query.alias())
             count_result = await db.execute(count_query)
             total = count_result.scalar_one()
 
-            # Apply sorting
             if sort_by and hasattr(User, sort_by):
                 sort_column = getattr(User, sort_by)
                 if sort_order.lower() == "desc":
@@ -154,7 +177,6 @@ class CRUDUser(CRUDBase[User, UserCreate, UserUpdate]):
                 else:
                     query = query.order_by(sort_column.asc())
 
-            # Apply pagination
             query = query.offset(skip).limit(limit)
             result = await db.execute(query)
             users = list(result.scalars().all())
@@ -162,88 +184,63 @@ class CRUDUser(CRUDBase[User, UserCreate, UserUpdate]):
             return users, total
 
         except Exception as e:
-            logger.error(f"Error retrieving paginated users: {str(e)}")
+            logger.error("Error retrieving paginated users: %s", e)
             raise
 
     async def bulk_update_status(
-        self,
-        db: AsyncSession,
-        *,
-        user_ids: List[UUID],
-        is_active: bool
+        self, db: AsyncSession, *, user_ids: list[UUID], is_active: bool
     ) -> int:
-        """
-        Bulk update is_active status for multiple users.
-
-        Args:
-            db: Database session
-            user_ids: List of user IDs to update
-            is_active: New active status
-
-        Returns:
-            Number of users updated
-        """
+        """Bulk update is_active status for multiple users."""
         try:
             if not user_ids:
                 return 0
 
-            # Use UPDATE with WHERE IN for efficiency
             stmt = (
                 update(User)
                 .where(User.id.in_(user_ids))
-                .where(User.deleted_at.is_(None))  # Don't update deleted users
-                .values(is_active=is_active, updated_at=datetime.now(timezone.utc))
+                .where(User.deleted_at.is_(None))
+                .values(is_active=is_active, updated_at=datetime.now(UTC))
             )
 
             result = await db.execute(stmt)
             await db.commit()
 
             updated_count = result.rowcount
-            logger.info(f"Bulk updated {updated_count} users to is_active={is_active}")
+            logger.info(
+                "Bulk updated %s users to is_active=%s", updated_count, is_active
+            )
             return updated_count
 
         except Exception as e:
             await db.rollback()
-            logger.error(f"Error bulk updating user status: {str(e)}", exc_info=True)
+            logger.exception("Error bulk updating user status: %s", e)
             raise
 
     async def bulk_soft_delete(
         self,
         db: AsyncSession,
         *,
-        user_ids: List[UUID],
-        exclude_user_id: Optional[UUID] = None
+        user_ids: list[UUID],
+        exclude_user_id: UUID | None = None,
     ) -> int:
-        """
-        Bulk soft delete multiple users.
-
-        Args:
-            db: Database session
-            user_ids: List of user IDs to delete
-            exclude_user_id: Optional user ID to exclude (e.g., the admin performing the action)
-
-        Returns:
-            Number of users deleted
-        """
+        """Bulk soft delete multiple users."""
         try:
             if not user_ids:
                 return 0
 
-            # Remove excluded user from list
             filtered_ids = [uid for uid in user_ids if uid != exclude_user_id]
 
             if not filtered_ids:
                 return 0
 
-            # Use UPDATE with WHERE IN for efficiency
             stmt = (
                 update(User)
                 .where(User.id.in_(filtered_ids))
-                .where(User.deleted_at.is_(None))  # Don't re-delete already deleted users
+                .where(User.deleted_at.is_(None))
                 .values(
-                    deleted_at=datetime.now(timezone.utc),
+                    deleted_at=datetime.now(UTC),
                     is_active=False,
-                    updated_at=datetime.now(timezone.utc)
+                    updated_at=datetime.now(UTC),
                 )
             )
 
@@ -251,22 +248,22 @@ class CRUDUser(CRUDBase[User, UserCreate, UserUpdate]):
             await db.commit()
 
             deleted_count = result.rowcount
-            logger.info(f"Bulk soft deleted {deleted_count} users")
+            logger.info("Bulk soft deleted %s users", deleted_count)
             return deleted_count
 
         except Exception as e:
             await db.rollback()
-            logger.error(f"Error bulk deleting users: {str(e)}", exc_info=True)
+            logger.exception("Error bulk deleting users: %s", e)
             raise
 
     def is_active(self, user: User) -> bool:
         """Check if user is active."""
-        return user.is_active
+        return bool(user.is_active)
 
     def is_superuser(self, user: User) -> bool:
         """Check if user is a superuser."""
-        return user.is_superuser
+        return bool(user.is_superuser)
 
 
-# Create a singleton instance for use across the application
-user = CRUDUser(User)
+# Singleton instance
+user_repo = UserRepository(User)

backend/app/schemas/common.py

@@ -1,18 +1,20 @@
 """
 Common schemas used across the API for pagination, responses, filtering, and sorting.
 """
+
 from enum import Enum
 from math import ceil
-from typing import Generic, TypeVar, List, Optional
+from typing import TypeVar
 from uuid import UUID
 
 from pydantic import BaseModel, Field
 
-T = TypeVar('T')
+T = TypeVar("T")
 
 
 class SortOrder(str, Enum):
     """Sort order options."""
+
     ASC = "asc"
     DESC = "desc"
 
@@ -20,16 +22,9 @@ class SortOrder(str, Enum):
 class PaginationParams(BaseModel):
     """Parameters for pagination."""
 
-    page: int = Field(
-        default=1,
-        ge=1,
-        description="Page number (1-indexed)"
-    )
+    page: int = Field(default=1, ge=1, description="Page number (1-indexed)")
     limit: int = Field(
-        default=20,
-        ge=1,
-        le=100,
-        description="Number of items per page (max 100)"
+        default=20, ge=1, le=100, description="Number of items per page (max 100)"
     )
 
     @property
@@ -42,34 +37,20 @@ class PaginationParams(BaseModel):
         """Alias for offset (compatibility with existing code)."""
         return self.offset
 
-    model_config = {
-        "json_schema_extra": {
-            "example": {
-                "page": 1,
-                "limit": 20
-            }
-        }
-    }
+    model_config = {"json_schema_extra": {"example": {"page": 1, "limit": 20}}}
 
 
 class SortParams(BaseModel):
     """Parameters for sorting."""
 
-    sort_by: Optional[str] = Field(
-        default=None,
-        description="Field name to sort by"
-    )
+    sort_by: str | None = Field(default=None, description="Field name to sort by")
     sort_order: SortOrder = Field(
-        default=SortOrder.ASC,
-        description="Sort order (asc or desc)"
+        default=SortOrder.ASC, description="Sort order (asc or desc)"
     )
 
     model_config = {
         "json_schema_extra": {
-            "example": {
-                "sort_by": "created_at",
-                "sort_order": "desc"
-            }
+            "example": {"sort_by": "created_at", "sort_order": "desc"}
         }
     }
 
@@ -92,32 +73,30 @@ class PaginationMeta(BaseModel):
                 "page_size": 20,
                 "total_pages": 8,
                 "has_next": True,
-                "has_prev": False
+                "has_prev": False,
             }
         }
     }
 
 
-class PaginatedResponse(BaseModel, Generic[T]):
+class PaginatedResponse[T](BaseModel):
     """Generic paginated response wrapper."""
 
-    data: List[T] = Field(..., description="List of items")
+    data: list[T] = Field(..., description="List of items")
     pagination: PaginationMeta = Field(..., description="Pagination metadata")
 
     model_config = {
         "json_schema_extra": {
             "example": {
-                "data": [
-                    {"id": "123", "name": "Example Item"}
-                ],
+                "data": [{"id": "123", "name": "Example Item"}],
                 "pagination": {
                     "total": 150,
                     "page": 1,
                     "page_size": 20,
                     "total_pages": 8,
                     "has_next": True,
-                    "has_prev": False
-                }
+                    "has_prev": False,
+                },
             }
         }
     }
@@ -131,10 +110,7 @@ class MessageResponse(BaseModel):
 
     model_config = {
         "json_schema_extra": {
-            "example": {
-                "success": True,
-                "message": "Operation completed successfully"
-            }
+            "example": {"success": True, "message": "Operation completed successfully"}
         }
     }
 
@@ -142,11 +118,11 @@ class MessageResponse(BaseModel):
 class BulkActionRequest(BaseModel):
     """Request schema for bulk operations on multiple items."""
 
-    ids: List[UUID] = Field(
+    ids: list[UUID] = Field(
         ...,
         min_length=1,
         max_length=100,
-        description="List of item IDs to perform action on (max 100)"
+        description="List of item IDs to perform action on (max 100)",
     )
 
     model_config = {
@@ -154,7 +130,7 @@ class BulkActionRequest(BaseModel):
             "example": {
                 "ids": [
                     "550e8400-e29b-41d4-a716-446655440000",
-                    "6ba7b810-9dad-11d1-80b4-00c04fd430c8"
+                    "6ba7b810-9dad-11d1-80b4-00c04fd430c8",
                 ]
             }
         }
@@ -166,24 +142,23 @@ class BulkActionResponse(BaseModel):
 
     success: bool = Field(default=True, description="Operation success status")
     message: str = Field(..., description="Human-readable message")
-    affected_count: int = Field(..., description="Number of items affected by the operation")
+    affected_count: int = Field(
+        ..., description="Number of items affected by the operation"
+    )
 
     model_config = {
         "json_schema_extra": {
             "example": {
                 "success": True,
                 "message": "Successfully deactivated 5 users",
-                "affected_count": 5
+                "affected_count": 5,
             }
         }
     }
 
 
 def create_pagination_meta(
-    total: int,
-    page: int,
-    limit: int,
-    items_count: int
+    total: int, page: int, limit: int, items_count: int
 ) -> PaginationMeta:
     """
     Helper function to create pagination metadata.
@@ -205,5 +180,5 @@ def create_pagination_meta(
         page_size=items_count,
         total_pages=total_pages,
         has_next=page < total_pages,
-        has_prev=page > 1
+        has_prev=page > 1,
     )

backend/app/schemas/errors.py

@@ -1,8 +1,8 @@
 """
 Error schemas for standardized API error responses.
 """
+
 from enum import Enum
-from typing import List, Optional
 
 from pydantic import BaseModel, Field
 
@@ -53,14 +53,14 @@ class ErrorDetail(BaseModel):
 
     code: ErrorCode = Field(..., description="Machine-readable error code")
     message: str = Field(..., description="Human-readable error message")
-    field: Optional[str] = Field(None, description="Field name if error is field-specific")
+    field: str | None = Field(None, description="Field name if error is field-specific")
 
     model_config = {
         "json_schema_extra": {
             "example": {
                 "code": "VAL_002",
                 "message": "Password must be at least 8 characters long",
-                "field": "password"
+                "field": "password",
             }
         }
     }
@@ -70,7 +70,7 @@ class ErrorResponse(BaseModel):
     """Standardized error response format."""
 
     success: bool = Field(default=False, description="Always false for error responses")
-    errors: List[ErrorDetail] = Field(..., description="List of errors that occurred")
+    errors: list[ErrorDetail] = Field(..., description="List of errors that occurred")
 
     model_config = {
         "json_schema_extra": {
@@ -80,9 +80,9 @@ class ErrorResponse(BaseModel):
                     {
                         "code": "AUTH_001",
                         "message": "Invalid email or password",
-                        "field": None
+                        "field": None,
                     }
-                ]
+                ],
             }
         }
     }

backend/app/schemas/oauth.py

@@ -0,0 +1,395 @@
+"""
+Pydantic schemas for OAuth authentication.
+"""
+
+from datetime import datetime
+from uuid import UUID
+
+from pydantic import BaseModel, ConfigDict, Field
+
+# ============================================================================
+# OAuth Provider Info (for frontend to display available providers)
+# ============================================================================
+
+
+class OAuthProviderInfo(BaseModel):
+    """Information about an available OAuth provider."""
+
+    provider: str = Field(..., description="Provider identifier (google, github)")
+    name: str = Field(..., description="Human-readable provider name")
+    icon: str | None = Field(None, description="Icon identifier for frontend")
+
+
+class OAuthProvidersResponse(BaseModel):
+    """Response containing list of enabled OAuth providers."""
+
+    enabled: bool = Field(..., description="Whether OAuth is globally enabled")
+    providers: list[OAuthProviderInfo] = Field(
+        default_factory=list, description="List of enabled providers"
+    )
+
+    model_config = ConfigDict(
+        json_schema_extra={
+            "example": {
+                "enabled": True,
+                "providers": [
+                    {"provider": "google", "name": "Google", "icon": "google"},
+                    {"provider": "github", "name": "GitHub", "icon": "github"},
+                ],
+            }
+        }
+    )
+
+
+# ============================================================================
+# OAuth Account (linked provider accounts)
+# ============================================================================
+
+
+class OAuthAccountBase(BaseModel):
+    """Base schema for OAuth accounts."""
+
+    provider: str = Field(..., max_length=50, description="OAuth provider name")
+    provider_email: str | None = Field(
+        None, max_length=255, description="Email from OAuth provider"
+    )
+
+
+class OAuthAccountCreate(OAuthAccountBase):
+    """Schema for creating an OAuth account link (internal use)."""
+
+    user_id: UUID
+    provider_user_id: str = Field(..., max_length=255)
+    access_token: str | None = None
+    refresh_token: str | None = None
+    token_expires_at: datetime | None = None
+
+
+class OAuthAccountResponse(OAuthAccountBase):
+    """Schema for OAuth account response to clients."""
+
+    id: UUID
+    created_at: datetime
+
+    model_config = ConfigDict(
+        from_attributes=True,
+        json_schema_extra={
+            "example": {
+                "id": "123e4567-e89b-12d3-a456-426614174000",
+                "provider": "google",
+                "provider_email": "user@gmail.com",
+                "created_at": "2025-11-24T12:00:00Z",
+            }
+        },
+    )
+
+
+class OAuthAccountsListResponse(BaseModel):
+    """Response containing list of linked OAuth accounts."""
+
+    accounts: list[OAuthAccountResponse]
+
+    model_config = ConfigDict(
+        json_schema_extra={
+            "example": {
+                "accounts": [
+                    {
+                        "id": "123e4567-e89b-12d3-a456-426614174000",
+                        "provider": "google",
+                        "provider_email": "user@gmail.com",
+                        "created_at": "2025-11-24T12:00:00Z",
+                    }
+                ]
+            }
+        }
+    )
+
+
+# ============================================================================
+# OAuth Flow (authorization, callback, etc.)
+# ============================================================================
+
+
+class OAuthAuthorizeRequest(BaseModel):
+    """Request parameters for OAuth authorization."""
+
+    provider: str = Field(..., description="OAuth provider (google, github)")
+    redirect_uri: str | None = Field(
+        None, description="Frontend callback URL after OAuth"
+    )
+    mode: str = Field(
+        default="login",
+        description="OAuth mode: login, register, or link",
+        pattern="^(login|register|link)$",
+    )
+
+
+class OAuthCallbackRequest(BaseModel):
+    """Request parameters for OAuth callback."""
+
+    code: str = Field(..., description="Authorization code from provider")
+    state: str = Field(..., description="State parameter for CSRF protection")
+
+
+class OAuthCallbackResponse(BaseModel):
+    """Response after successful OAuth authentication."""
+
+    access_token: str = Field(..., description="JWT access token")
+    refresh_token: str = Field(..., description="JWT refresh token")
+    token_type: str = Field(default="bearer")
+    expires_in: int = Field(..., description="Token expiration in seconds")
+    is_new_user: bool = Field(
+        default=False, description="Whether a new user was created"
+    )
+
+    model_config = ConfigDict(
+        json_schema_extra={
+            "example": {
+                "access_token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...",
+                "refresh_token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...",
+                "token_type": "bearer",
+                "expires_in": 900,
+                "is_new_user": False,
+            }
+        }
+    )
+
+
+class OAuthUnlinkResponse(BaseModel):
+    """Response after unlinking an OAuth account."""
+
+    success: bool = Field(..., description="Whether the unlink was successful")
+    message: str = Field(..., description="Status message")
+
+    model_config = ConfigDict(
+        json_schema_extra={
+            "example": {"success": True, "message": "Google account unlinked"}
+        }
+    )
+
+
+# ============================================================================
+# OAuth State (CSRF protection - internal use)
+# ============================================================================
+
+
+class OAuthStateCreate(BaseModel):
+    """Schema for creating OAuth state (internal use)."""
+
+    state: str = Field(..., max_length=255)
+    code_verifier: str | None = Field(None, max_length=128)
+    nonce: str | None = Field(None, max_length=255)
+    provider: str = Field(..., max_length=50)
+    redirect_uri: str | None = Field(None, max_length=500)
+    user_id: UUID | None = None
+    expires_at: datetime
+
+
+# ============================================================================
+# OAuth Client (Provider Mode - MCP clients)
+# ============================================================================
+
+
+class OAuthClientBase(BaseModel):
+    """Base schema for OAuth clients."""
+
+    client_name: str = Field(..., max_length=255, description="Client application name")
+    client_description: str | None = Field(
+        None, max_length=1000, description="Client description"
+    )
+    redirect_uris: list[str] = Field(
+        default_factory=list, description="Allowed redirect URIs"
+    )
+    allowed_scopes: list[str] = Field(
+        default_factory=list, description="Allowed OAuth scopes"
+    )
+
+
+class OAuthClientCreate(OAuthClientBase):
+    """Schema for creating an OAuth client."""
+
+    client_type: str = Field(
+        default="public",
+        description="Client type: public or confidential",
+        pattern="^(public|confidential)$",
+    )
+
+
+class OAuthClientResponse(OAuthClientBase):
+    """Schema for OAuth client response."""
+
+    id: UUID
+    client_id: str = Field(..., description="OAuth client ID")
+    client_type: str
+    is_active: bool
+    created_at: datetime
+
+    model_config = ConfigDict(
+        from_attributes=True,
+        json_schema_extra={
+            "example": {
+                "id": "123e4567-e89b-12d3-a456-426614174000",
+                "client_id": "abc123def456",
+                "client_name": "My MCP App",
+                "client_description": "My application that uses MCP",
+                "client_type": "public",
+                "redirect_uris": ["http://localhost:3000/callback"],
+                "allowed_scopes": ["read:users", "write:users"],
+                "is_active": True,
+                "created_at": "2025-11-24T12:00:00Z",
+            }
+        },
+    )
+
+
+class OAuthClientWithSecret(OAuthClientResponse):
+    """Schema for OAuth client response including secret (only shown once)."""
+
+    client_secret: str | None = Field(
+        None, description="Client secret (only shown once for confidential clients)"
+    )
+
+    model_config = ConfigDict(
+        from_attributes=True,
+        json_schema_extra={
+            "example": {
+                "id": "123e4567-e89b-12d3-a456-426614174000",
+                "client_id": "abc123def456",
+                "client_secret": "secret_xyz789",
+                "client_name": "My MCP App",
+                "client_type": "confidential",
+                "redirect_uris": ["http://localhost:3000/callback"],
+                "allowed_scopes": ["read:users"],
+                "is_active": True,
+                "created_at": "2025-11-24T12:00:00Z",
+            }
+        },
+    )
+
+
+# ============================================================================
+# OAuth Provider Discovery (RFC 8414 - skeleton)
+# ============================================================================
+
+
+class OAuthServerMetadata(BaseModel):
+    """OAuth 2.0 Authorization Server Metadata (RFC 8414)."""
+
+    issuer: str = Field(..., description="Authorization server issuer URL")
+    authorization_endpoint: str = Field(..., description="Authorization endpoint URL")
+    token_endpoint: str = Field(..., description="Token endpoint URL")
+    registration_endpoint: str | None = Field(
+        None, description="Dynamic client registration endpoint"
+    )
+    revocation_endpoint: str | None = Field(
+        None, description="Token revocation endpoint"
+    )
+    introspection_endpoint: str | None = Field(
+        None, description="Token introspection endpoint (RFC 7662)"
+    )
+    scopes_supported: list[str] = Field(
+        default_factory=list, description="Supported scopes"
+    )
+    response_types_supported: list[str] = Field(
+        default_factory=lambda: ["code"], description="Supported response types"
+    )
+    grant_types_supported: list[str] = Field(
+        default_factory=lambda: ["authorization_code", "refresh_token"],
+        description="Supported grant types",
+    )
+    code_challenge_methods_supported: list[str] = Field(
+        default_factory=lambda: ["S256"], description="Supported PKCE methods"
+    )
+    token_endpoint_auth_methods_supported: list[str] = Field(
+        default_factory=lambda: ["client_secret_basic", "client_secret_post", "none"],
+        description="Supported client authentication methods",
+    )
+
+    model_config = ConfigDict(
+        json_schema_extra={
+            "example": {
+                "issuer": "https://api.example.com",
+                "authorization_endpoint": "https://api.example.com/oauth/authorize",
+                "token_endpoint": "https://api.example.com/oauth/token",
+                "revocation_endpoint": "https://api.example.com/oauth/revoke",
+                "introspection_endpoint": "https://api.example.com/oauth/introspect",
+                "scopes_supported": ["openid", "profile", "email", "read:users"],
+                "response_types_supported": ["code"],
+                "grant_types_supported": ["authorization_code", "refresh_token"],
+                "code_challenge_methods_supported": ["S256"],
+                "token_endpoint_auth_methods_supported": [
+                    "client_secret_basic",
+                    "client_secret_post",
+                    "none",
+                ],
+            }
+        }
+    )
+
+
+# ============================================================================
+# OAuth Token Responses (RFC 6749)
+# ============================================================================
+
+
+class OAuthTokenResponse(BaseModel):
+    """OAuth 2.0 Token Response (RFC 6749 Section 5.1)."""
+
+    access_token: str = Field(..., description="The access token issued by the server")
+    token_type: str = Field(
+        default="Bearer", description="The type of token (typically 'Bearer')"
+    )
+    expires_in: int | None = Field(None, description="Token lifetime in seconds")
+    refresh_token: str | None = Field(
+        None, description="Refresh token for obtaining new access tokens"
+    )
+    scope: str | None = Field(
+        None, description="Space-separated list of granted scopes"
+    )
+
+    model_config = ConfigDict(
+        json_schema_extra={
+            "example": {
+                "access_token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...",
+                "token_type": "Bearer",
+                "expires_in": 3600,
+                "refresh_token": "dGhpcyBpcyBhIHJlZnJlc2ggdG9rZW4...",
+                "scope": "openid profile email",
+            }
+        }
+    )
+
+
+class OAuthTokenIntrospectionResponse(BaseModel):
+    """OAuth 2.0 Token Introspection Response (RFC 7662)."""
+
+    active: bool = Field(..., description="Whether the token is currently active")
+    scope: str | None = Field(None, description="Space-separated list of scopes")
+    client_id: str | None = Field(None, description="Client identifier for the token")
+    username: str | None = Field(
+        None, description="Human-readable identifier for the resource owner"
+    )
+    token_type: str | None = Field(
+        None, description="Type of the token (e.g., 'Bearer')"
+    )
+    exp: int | None = Field(None, description="Token expiration time (Unix timestamp)")
+    iat: int | None = Field(None, description="Token issue time (Unix timestamp)")
+    nbf: int | None = Field(None, description="Token not-before time (Unix timestamp)")
+    sub: str | None = Field(None, description="Subject of the token (user ID)")
+    aud: str | None = Field(None, description="Intended audience of the token")
+    iss: str | None = Field(None, description="Issuer of the token")
+
+    model_config = ConfigDict(
+        json_schema_extra={
+            "example": {
+                "active": True,
+                "scope": "openid profile",
+                "client_id": "client123",
+                "username": "user@example.com",
+                "token_type": "Bearer",
+                "exp": 1735689600,
+                "iat": 1735686000,
+                "sub": "user-uuid-here",
+            }
+        }
+    )

backend/app/schemas/organizations.py

@@ -1,10 +1,10 @@
 # app/schemas/organizations.py
 import re
 from datetime import datetime
-from typing import Optional, Dict, Any, List
+from typing import Any
 from uuid import UUID
 
-from pydantic import BaseModel, field_validator, ConfigDict, Field
+from pydantic import BaseModel, ConfigDict, Field, field_validator
 
 from app.models.user_organization import OrganizationRole
 
@@ -12,85 +12,94 @@ from app.models.user_organization import OrganizationRole
 # Organization Schemas
 class OrganizationBase(BaseModel):
     """Base organization schema with common fields."""
-    name: str = Field(..., min_length=1, max_length=255)
-    slug: Optional[str] = Field(None, min_length=1, max_length=255)
-    description: Optional[str] = None
-    is_active: bool = True
-    settings: Optional[Dict[str, Any]] = {}
 
-    @field_validator('slug')
+    name: str = Field(..., min_length=1, max_length=255)
+    slug: str | None = Field(None, min_length=1, max_length=255)
+    description: str | None = None
+    is_active: bool = True
+    settings: dict[str, Any] | None = {}
+
+    @field_validator("slug")
     @classmethod
-    def validate_slug(cls, v: Optional[str]) -> Optional[str]:
+    def validate_slug(cls, v: str | None) -> str | None:
         """Validate slug format: lowercase, alphanumeric, hyphens only."""
         if v is None:
             return v
-        if not re.match(r'^[a-z0-9-]+$', v):
-            raise ValueError('Slug must contain only lowercase letters, numbers, and hyphens')
-        if v.startswith('-') or v.endswith('-'):
-            raise ValueError('Slug cannot start or end with a hyphen')
-        if '--' in v:
-            raise ValueError('Slug cannot contain consecutive hyphens')
+        if not re.match(r"^[a-z0-9-]+$", v):
+            raise ValueError(
+                "Slug must contain only lowercase letters, numbers, and hyphens"
+            )
+        if v.startswith("-") or v.endswith("-"):
+            raise ValueError("Slug cannot start or end with a hyphen")
+        if "--" in v:
+            raise ValueError("Slug cannot contain consecutive hyphens")
         return v
 
-    @field_validator('name')
+    @field_validator("name")
     @classmethod
     def validate_name(cls, v: str) -> str:
         """Validate organization name."""
         if not v or v.strip() == "":
-            raise ValueError('Organization name cannot be empty')
+            raise ValueError("Organization name cannot be empty")
         return v.strip()
 
 
 class OrganizationCreate(OrganizationBase):
     """Schema for creating a new organization."""
+
     name: str = Field(..., min_length=1, max_length=255)
-    slug: str = Field(..., min_length=1, max_length=255)
+    slug: str = Field(..., min_length=1, max_length=255)  # pyright: ignore[reportIncompatibleVariableOverride]
 
 
 class OrganizationUpdate(BaseModel):
     """Schema for updating an organization."""
-    name: Optional[str] = Field(None, min_length=1, max_length=255)
-    slug: Optional[str] = Field(None, min_length=1, max_length=255)
-    description: Optional[str] = None
-    is_active: Optional[bool] = None
-    settings: Optional[Dict[str, Any]] = None
 
-    @field_validator('slug')
+    name: str | None = Field(None, min_length=1, max_length=255)
+    slug: str | None = Field(None, min_length=1, max_length=255)
+    description: str | None = None
+    is_active: bool | None = None
+    settings: dict[str, Any] | None = None
+
+    @field_validator("slug")
     @classmethod
-    def validate_slug(cls, v: Optional[str]) -> Optional[str]:
+    def validate_slug(cls, v: str | None) -> str | None:
         """Validate slug format."""
         if v is None:
             return v
-        if not re.match(r'^[a-z0-9-]+$', v):
-            raise ValueError('Slug must contain only lowercase letters, numbers, and hyphens')
-        if v.startswith('-') or v.endswith('-'):
-            raise ValueError('Slug cannot start or end with a hyphen')
-        if '--' in v:
-            raise ValueError('Slug cannot contain consecutive hyphens')
+        if not re.match(r"^[a-z0-9-]+$", v):
+            raise ValueError(
+                "Slug must contain only lowercase letters, numbers, and hyphens"
+            )
+        if v.startswith("-") or v.endswith("-"):
+            raise ValueError("Slug cannot start or end with a hyphen")
+        if "--" in v:
+            raise ValueError("Slug cannot contain consecutive hyphens")
         return v
 
-    @field_validator('name')
+    @field_validator("name")
     @classmethod
-    def validate_name(cls, v: Optional[str]) -> Optional[str]:
+    def validate_name(cls, v: str | None) -> str | None:
         """Validate organization name."""
         if v is not None and (not v or v.strip() == ""):
-            raise ValueError('Organization name cannot be empty')
+            raise ValueError("Organization name cannot be empty")
         return v.strip() if v else v
 
 
 class OrganizationResponse(OrganizationBase):
     """Schema for organization API responses."""
+
     id: UUID
     created_at: datetime
-    updated_at: Optional[datetime] = None
-    member_count: Optional[int] = 0
+    updated_at: datetime | None = None
+    member_count: int | None = 0
 
     model_config = ConfigDict(from_attributes=True)
 
 
 class OrganizationListResponse(BaseModel):
     """Schema for paginated organization list responses."""
-    organizations: List[OrganizationResponse]
+
+    organizations: list[OrganizationResponse]
     total: int
     page: int
     page_size: int
@@ -100,44 +109,49 @@ class OrganizationListResponse(BaseModel):
 # User-Organization Relationship Schemas
 class UserOrganizationBase(BaseModel):
     """Base schema for user-organization relationship."""
+
     role: OrganizationRole = OrganizationRole.MEMBER
     is_active: bool = True
-    custom_permissions: Optional[str] = None
+    custom_permissions: str | None = None
 
 
 class UserOrganizationCreate(BaseModel):
     """Schema for adding a user to an organization."""
+
     user_id: UUID
     role: OrganizationRole = OrganizationRole.MEMBER
-    custom_permissions: Optional[str] = None
+    custom_permissions: str | None = None
 
 
 class UserOrganizationUpdate(BaseModel):
     """Schema for updating user's role in an organization."""
-    role: Optional[OrganizationRole] = None
-    is_active: Optional[bool] = None
-    custom_permissions: Optional[str] = None
+
+    role: OrganizationRole | None = None
+    is_active: bool | None = None
+    custom_permissions: str | None = None
 
 
 class UserOrganizationResponse(BaseModel):
     """Schema for user-organization relationship responses."""
+
     user_id: UUID
     organization_id: UUID
     role: OrganizationRole
     is_active: bool
-    custom_permissions: Optional[str] = None
+    custom_permissions: str | None = None
     created_at: datetime
-    updated_at: Optional[datetime] = None
+    updated_at: datetime | None = None
 
     model_config = ConfigDict(from_attributes=True)
 
 
 class OrganizationMemberResponse(BaseModel):
     """Schema for organization member information."""
+
     user_id: UUID
     email: str
     first_name: str
-    last_name: Optional[str] = None
+    last_name: str | None = None
     role: OrganizationRole
     is_active: bool
     joined_at: datetime
@@ -147,7 +161,8 @@ class OrganizationMemberResponse(BaseModel):
 
 class OrganizationMemberListResponse(BaseModel):
     """Schema for paginated organization member list."""
-    members: List[OrganizationMemberResponse]
+
+    members: list[OrganizationMemberResponse]
     total: int
     page: int
     page_size: int

backend/app/schemas/sessions.py

@@ -1,37 +1,44 @@
 """
 Pydantic schemas for user session management.
 """
+
 from datetime import datetime
-from typing import Optional
 from uuid import UUID
 
-from pydantic import BaseModel, Field, ConfigDict
+from pydantic import BaseModel, ConfigDict, Field
 
 
 class SessionBase(BaseModel):
     """Base schema for user sessions."""
-    device_name: Optional[str] = Field(None, max_length=255, description="Friendly device name")
-    device_id: Optional[str] = Field(None, max_length=255, description="Persistent device identifier")
+
+    device_name: str | None = Field(
+        None, max_length=255, description="Friendly device name"
+    )
+    device_id: str | None = Field(
+        None, max_length=255, description="Persistent device identifier"
+    )
 
 
 class SessionCreate(SessionBase):
     """Schema for creating a new session (internal use)."""
+
     user_id: UUID
     refresh_token_jti: str = Field(..., max_length=255)
-    ip_address: Optional[str] = Field(None, max_length=45)
-    user_agent: Optional[str] = Field(None, max_length=500)
+    ip_address: str | None = Field(None, max_length=45)
+    user_agent: str | None = Field(None, max_length=500)
     last_used_at: datetime
     expires_at: datetime
-    location_city: Optional[str] = Field(None, max_length=100)
-    location_country: Optional[str] = Field(None, max_length=100)
+    location_city: str | None = Field(None, max_length=100)
+    location_country: str | None = Field(None, max_length=100)
 
 
 class SessionUpdate(BaseModel):
     """Schema for updating a session (internal use)."""
-    last_used_at: Optional[datetime] = None
-    is_active: Optional[bool] = None
-    refresh_token_jti: Optional[str] = None
-    expires_at: Optional[datetime] = None
+
+    last_used_at: datetime | None = None
+    is_active: bool | None = None
+    refresh_token_jti: str | None = None
+    expires_at: datetime | None = None
 
 
 class SessionResponse(SessionBase):
@@ -40,14 +47,17 @@ class SessionResponse(SessionBase):
 
     This is what users see when they list their active sessions.
     """
+
     id: UUID
-    ip_address: Optional[str] = None
-    location_city: Optional[str] = None
-    location_country: Optional[str] = None
+    ip_address: str | None = None
+    location_city: str | None = None
+    location_country: str | None = None
     last_used_at: datetime
     created_at: datetime
     expires_at: datetime
-    is_current: bool = Field(default=False, description="Whether this is the current session")
+    is_current: bool = Field(
+        default=False, description="Whether this is the current session"
+    )
 
     model_config = ConfigDict(
         from_attributes=True,
@@ -62,14 +72,15 @@ class SessionResponse(SessionBase):
                 "last_used_at": "2025-10-31T12:00:00Z",
                 "created_at": "2025-10-30T09:00:00Z",
                 "expires_at": "2025-11-06T09:00:00Z",
-                "is_current": True
+                "is_current": True,
             }
-        }
+        },
     )
 
 
 class SessionListResponse(BaseModel):
     """Response containing list of sessions."""
+
     sessions: list[SessionResponse]
     total: int = Field(..., description="Total number of active sessions")
 
@@ -84,10 +95,10 @@ class SessionListResponse(BaseModel):
                         "last_used_at": "2025-10-31T12:00:00Z",
                         "created_at": "2025-10-30T09:00:00Z",
                         "expires_at": "2025-11-06T09:00:00Z",
-                        "is_current": True
+                        "is_current": True,
                     }
                 ],
-                "total": 1
+                "total": 1,
             }
         }
     )
@@ -95,17 +106,14 @@ class SessionListResponse(BaseModel):
 
 class LogoutRequest(BaseModel):
     """Request schema for logout endpoint."""
+
     refresh_token: str = Field(
-        ...,
-        description="Refresh token for the session to logout from",
-        min_length=10
+        ..., description="Refresh token for the session to logout from", min_length=10
     )
 
     model_config = ConfigDict(
         json_schema_extra={
-            "example": {
-                "refresh_token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9..."
-            }
+            "example": {"refresh_token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9..."}
         }
     )
 
@@ -116,13 +124,14 @@ class AdminSessionResponse(SessionBase):
 
     Includes user information for admin to see who owns each session.
     """
+
     id: UUID
     user_id: UUID
     user_email: str = Field(..., description="Email of the user who owns this session")
-    user_full_name: Optional[str] = Field(None, description="Full name of the user")
-    ip_address: Optional[str] = None
-    location_city: Optional[str] = None
-    location_country: Optional[str] = None
+    user_full_name: str | None = Field(None, description="Full name of the user")
+    ip_address: str | None = None
+    location_city: str | None = None
+    location_country: str | None = None
     last_used_at: datetime
     created_at: datetime
     expires_at: datetime
@@ -144,20 +153,21 @@ class AdminSessionResponse(SessionBase):
                 "last_used_at": "2025-10-31T12:00:00Z",
                 "created_at": "2025-10-30T09:00:00Z",
                 "expires_at": "2025-11-06T09:00:00Z",
-                "is_active": True
+                "is_active": True,
             }
-        }
+        },
     )
 
 
 class DeviceInfo(BaseModel):
     """Device information extracted from request."""
-    device_name: Optional[str] = None
-    device_id: Optional[str] = None
-    ip_address: Optional[str] = None
-    user_agent: Optional[str] = None
-    location_city: Optional[str] = None
-    location_country: Optional[str] = None
+
+    device_name: str | None = None
+    device_id: str | None = None
+    ip_address: str | None = None
+    user_agent: str | None = None
+    location_city: str | None = None
+    location_country: str | None = None
 
     model_config = ConfigDict(
         json_schema_extra={
@@ -167,7 +177,7 @@ class DeviceInfo(BaseModel):
                 "ip_address": "192.168.1.50",
                 "user_agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7)...",
                 "location_city": "San Francisco",
-                "location_country": "United States"
+                "location_country": "United States",
             }
         }
     )

backend/app/schemas/users.py

@@ -1,9 +1,9 @@
 # app/schemas/users.py
 from datetime import datetime
-from typing import Optional, Dict, Any
+from typing import Any
 from uuid import UUID
 
-from pydantic import BaseModel, EmailStr, field_validator, ConfigDict, Field
+from pydantic import BaseModel, ConfigDict, EmailStr, Field, field_validator
 
 from app.schemas.validators import validate_password_strength, validate_phone_number
 
@@ -11,20 +11,21 @@ from app.schemas.validators import validate_password_strength, validate_phone_nu
 class UserBase(BaseModel):
     email: EmailStr
     first_name: str
-    last_name: Optional[str] = None
-    phone_number: Optional[str] = None
+    last_name: str | None = None
+    phone_number: str | None = None
 
-    @field_validator('phone_number')
+    @field_validator("phone_number")
     @classmethod
-    def validate_phone(cls, v: Optional[str]) -> Optional[str]:
+    def validate_phone(cls, v: str | None) -> str | None:
         return validate_phone_number(v)
 
 
 class UserCreate(UserBase):
     password: str
     is_superuser: bool = False
+    is_active: bool = True
 
-    @field_validator('password')
+    @field_validator("password")
     @classmethod
     def password_strength(cls, v: str) -> str:
         """Enterprise-grade password strength validation"""
@@ -32,30 +33,57 @@ class UserCreate(UserBase):
 
 
 class UserUpdate(BaseModel):
-    first_name: Optional[str] = None
-    last_name: Optional[str] = None
-    phone_number: Optional[str] = None
-    password: Optional[str] = None
-    preferences: Optional[Dict[str, Any]] = None
-    is_active: Optional[bool] = None  # Changed default from True to None to avoid unintended updates
-    is_superuser: Optional[bool] = None  # Explicitly reject privilege escalation attempts
+    first_name: str | None = None
+    last_name: str | None = None
+    phone_number: str | None = None
+    password: str | None = None
+    preferences: dict[str, Any] | None = None
+    locale: str | None = Field(
+        None,
+        max_length=10,
+        pattern=r"^[a-z]{2}(-[A-Z]{2})?$",
+        description="User's preferred locale (BCP 47 format: en, it, en-US, it-IT)",
+        examples=["en", "it", "en-US", "it-IT"],
+    )
+    is_active: bool | None = (
+        None  # Changed default from True to None to avoid unintended updates
+    )
+    is_superuser: bool | None = None  # Explicitly reject privilege escalation attempts
 
-    @field_validator('phone_number')
+    @field_validator("phone_number")
     @classmethod
-    def validate_phone(cls, v: Optional[str]) -> Optional[str]:
+    def validate_phone(cls, v: str | None) -> str | None:
         return validate_phone_number(v)
 
-    @field_validator('password')
+    @field_validator("password")
     @classmethod
-    def password_strength(cls, v: Optional[str]) -> Optional[str]:
+    def password_strength(cls, v: str | None) -> str | None:
         """Enterprise-grade password strength validation"""
         if v is None:
             return v
         return validate_password_strength(v)
 
-    @field_validator('is_superuser')
+    @field_validator("locale")
     @classmethod
-    def prevent_superuser_modification(cls, v: Optional[bool]) -> Optional[bool]:
+    def validate_locale(cls, v: str | None) -> str | None:
+        """Validate locale against supported locales."""
+        if v is None:
+            return v
+        # Only support English and Italian for template showcase
+        # Note: Locales stored in lowercase for case-insensitive matching
+        supported_locales = {"en", "it", "en-us", "en-gb", "it-it"}
+        # Normalize to lowercase for comparison and storage
+        v_lower = v.lower()
+        if v_lower not in supported_locales:
+            raise ValueError(
+                f"Unsupported locale '{v}'. Supported locales: {sorted(supported_locales)}"
+            )
+        # Return normalized lowercase version for consistency
+        return v_lower
+
+    @field_validator("is_superuser")
+    @classmethod
+    def prevent_superuser_modification(cls, v: bool | None) -> bool | None:
         """Prevent users from modifying their superuser status via this schema."""
         if v is not None:
             raise ValueError("Cannot modify superuser status through user update")
@@ -67,7 +95,8 @@ class UserInDB(UserBase):
     is_active: bool
     is_superuser: bool
     created_at: datetime
-    updated_at: Optional[datetime] = None
+    updated_at: datetime | None = None
+    locale: str | None = None
 
     model_config = ConfigDict(from_attributes=True)
 
@@ -77,28 +106,29 @@ class UserResponse(UserBase):
     is_active: bool
     is_superuser: bool
     created_at: datetime
-    updated_at: Optional[datetime] = None
+    updated_at: datetime | None = None
+    locale: str | None = None
 
     model_config = ConfigDict(from_attributes=True)
 
 
 class Token(BaseModel):
     access_token: str
-    refresh_token: Optional[str] = None
+    refresh_token: str | None = None
     token_type: str = "bearer"
     user: "UserResponse"  # Forward reference since UserResponse is defined above
-    expires_in: Optional[int] = None  # Token expiration in seconds
+    expires_in: int | None = None  # Token expiration in seconds
 
 
 class TokenPayload(BaseModel):
     sub: str  # User ID
     exp: int  # Expiration time
-    iat: Optional[int] = None  # Issued at
-    jti: Optional[str] = None  # JWT ID
-    is_superuser: Optional[bool] = False
-    first_name: Optional[str] = None
-    email: Optional[str] = None
-    type: Optional[str] = None  # Token type (access/refresh)
+    iat: int | None = None  # Issued at
+    jti: str | None = None  # JWT ID
+    is_superuser: bool | None = False
+    first_name: str | None = None
+    email: str | None = None
+    type: str | None = None  # Token type (access/refresh)
 
 
 class TokenData(BaseModel):
@@ -108,10 +138,11 @@ class TokenData(BaseModel):
 
 class PasswordChange(BaseModel):
     """Schema for changing password (requires current password)."""
+
     current_password: str
     new_password: str
 
-    @field_validator('new_password')
+    @field_validator("new_password")
     @classmethod
     def password_strength(cls, v: str) -> str:
         """Enterprise-grade password strength validation"""
@@ -120,10 +151,11 @@ class PasswordChange(BaseModel):
 
 class PasswordReset(BaseModel):
     """Schema for resetting password (via email token)."""
+
     token: str
     new_password: str
 
-    @field_validator('new_password')
+    @field_validator("new_password")
     @classmethod
     def password_strength(cls, v: str) -> str:
         """Enterprise-grade password strength validation"""
@@ -141,23 +173,19 @@ class RefreshTokenRequest(BaseModel):
 
 class PasswordResetRequest(BaseModel):
     """Schema for requesting a password reset."""
+
     email: EmailStr = Field(..., description="Email address of the account")
 
-    model_config = {
-        "json_schema_extra": {
-            "example": {
-                "email": "user@example.com"
-            }
-        }
-    }
+    model_config = {"json_schema_extra": {"example": {"email": "user@example.com"}}}
 
 
 class PasswordResetConfirm(BaseModel):
     """Schema for confirming a password reset with token."""
+
     token: str = Field(..., description="Password reset token from email")
     new_password: str = Field(..., min_length=8, description="New password")
 
-    @field_validator('new_password')
+    @field_validator("new_password")
     @classmethod
     def password_strength(cls, v: str) -> str:
         """Enterprise-grade password strength validation"""
@@ -167,7 +195,7 @@ class PasswordResetConfirm(BaseModel):
         "json_schema_extra": {
             "example": {
                 "token": "eyJwYXlsb2FkIjp7ImVtYWlsIjoidXNlckBleGFtcGxlLmNvbSIsImV4cCI6MTcxMjM0NTY3OH19",
-                "new_password": "NewSecurePassword123"
+                "new_password": "NewSecurePassword123",
             }
         }
     }

backend/app/schemas/validators.py

@@ -4,19 +4,34 @@ Shared validators for Pydantic schemas.
 This module provides reusable validation functions to ensure consistency
 across all schemas and avoid code duplication.
 """
+
 import re
-from typing import Set
 
 # Common weak passwords that should be rejected
-COMMON_PASSWORDS: Set[str] = {
-    'password', 'password1', 'password123', 'password1234',
-    'admin', 'admin123', 'admin1234',
-    'welcome', 'welcome1', 'welcome123',
-    'qwerty', 'qwerty123',
-    '12345678', '123456789', '1234567890',
-    'letmein', 'letmein1', 'letmein123',
-    'monkey123', 'dragon123',
-    'passw0rd', 'p@ssw0rd', 'p@ssword',
+COMMON_PASSWORDS: set[str] = {
+    "password",
+    "password1",
+    "password123",
+    "password1234",
+    "admin",
+    "admin123",
+    "admin1234",
+    "welcome",
+    "welcome1",
+    "welcome123",
+    "qwerty",
+    "qwerty123",
+    "12345678",
+    "123456789",
+    "1234567890",
+    "letmein",
+    "letmein1",
+    "letmein123",
+    "monkey123",
+    "dragon123",
+    "passw0rd",
+    "p@ssw0rd",
+    "p@ssword",
 }
 
 
@@ -45,20 +60,32 @@ def validate_password_strength(password: str) -> str:
         >>> validate_password_strength("MySecureP@ss123")  # Valid
         >>> validate_password_strength("password1")  # Invalid - too weak
     """
+    # Check if we are in demo mode
+    from app.core.config import settings
+
+    if settings.DEMO_MODE:
+        # In demo mode, allow specific weak passwords for demo accounts
+        demo_passwords = {"Demo123!", "Admin123!"}
+        if password in demo_passwords:
+            return password
+
     # Check minimum length
     if len(password) < 12:
-        raise ValueError('Password must be at least 12 characters long')
+        raise ValueError("Password must be at least 12 characters long")
 
     # Check against common passwords (case-insensitive)
     if password.lower() in COMMON_PASSWORDS:
-        raise ValueError('Password is too common. Please choose a stronger password')
+        raise ValueError("Password is too common. Please choose a stronger password")
 
     # Check for required character types
     checks = [
-        (any(c.islower() for c in password), 'at least one lowercase letter'),
-        (any(c.isupper() for c in password), 'at least one uppercase letter'),
-        (any(c.isdigit() for c in password), 'at least one digit'),
-        (any(c in '!@#$%^&*()_+-=[]{}|;:,.<>?~`' for c in password), 'at least one special character (!@#$%^&*()_+-=[]{}|;:,.<>?~`)')
+        (any(c.islower() for c in password), "at least one lowercase letter"),
+        (any(c.isupper() for c in password), "at least one uppercase letter"),
+        (any(c.isdigit() for c in password), "at least one digit"),
+        (
+            any(c in "!@#$%^&*()_+-=[]{}|;:,.<>?~`" for c in password),
+            "at least one special character (!@#$%^&*()_+-=[]{}|;:,.<>?~`)",
+        ),
     ]
 
     failed = [msg for check, msg in checks if not check]
@@ -94,10 +121,10 @@ def validate_phone_number(phone: str | None) -> str | None:
 
     # Check for empty strings
     if not phone or phone.strip() == "":
-        raise ValueError('Phone number cannot be empty')
+        raise ValueError("Phone number cannot be empty")
 
     # Remove all spaces and formatting characters
-    cleaned = re.sub(r'[\s\-\(\)]', '', phone)
+    cleaned = re.sub(r"[\s\-\(\)]", "", phone)
 
     # Basic pattern:
     # Must start with + or 0
@@ -105,19 +132,19 @@ def validate_phone_number(phone: str | None) -> str | None:
     # After 0 must have at least 8 digits
     # Maximum total length of 15 digits (international standard)
     # Only allowed characters are + at start and digits
-    pattern = r'^(?:\+[0-9]{8,14}|0[0-9]{8,14})$'
+    pattern = r"^(?:\+[0-9]{8,14}|0[0-9]{8,14})$"
 
     if not re.match(pattern, cleaned):
-        raise ValueError('Phone number must start with + or 0 followed by 8-14 digits')
+        raise ValueError("Phone number must start with + or 0 followed by 8-14 digits")
 
     # Additional validation to catch specific invalid cases
     # NOTE: These checks are defensive code - the regex pattern above already catches these cases
-    if cleaned.count('+') > 1:  # pragma: no cover
-        raise ValueError('Phone number can only contain one + symbol at the start')
+    if cleaned.count("+") > 1:  # pragma: no cover
+        raise ValueError("Phone number can only contain one + symbol at the start")
 
     # Check for any non-digit characters (except the leading +)
     if not all(c.isdigit() for c in cleaned[1:]):  # pragma: no cover
-        raise ValueError('Phone number can only contain digits after the prefix')
+        raise ValueError("Phone number can only contain digits after the prefix")
 
     return cleaned
 
@@ -169,16 +196,16 @@ def validate_slug(slug: str) -> str:
         ValueError: If slug format is invalid
     """
     if not slug or len(slug) < 2:
-        raise ValueError('Slug must be at least 2 characters long')
+        raise ValueError("Slug must be at least 2 characters long")
 
     if len(slug) > 50:
-        raise ValueError('Slug must be at most 50 characters long')
+        raise ValueError("Slug must be at most 50 characters long")
 
     # Check format
-    if not re.match(r'^[a-z0-9]+(?:-[a-z0-9]+)*$', slug):
+    if not re.match(r"^[a-z0-9]+(?:-[a-z0-9]+)*$", slug):
         raise ValueError(
-            'Slug can only contain lowercase letters, numbers, and hyphens. '
-            'It cannot start or end with a hyphen, and cannot contain consecutive hyphens'
+            "Slug can only contain lowercase letters, numbers, and hyphens. "
+            "It cannot start or end with a hyphen, and cannot contain consecutive hyphens"
         )
 
     return slug

backend/app/services/__init__.py

@@ -0,0 +1,19 @@
+# app/services/__init__.py
+from . import oauth_provider_service
+from .auth_service import AuthService
+from .oauth_service import OAuthService
+from .organization_service import OrganizationService, organization_service
+from .session_service import SessionService, session_service
+from .user_service import UserService, user_service
+
+__all__ = [
+    "AuthService",
+    "OAuthService",
+    "OrganizationService",
+    "SessionService",
+    "UserService",
+    "oauth_provider_service",
+    "organization_service",
+    "session_service",
+    "user_service",
+]

backend/app/services/auth_service.py

@@ -1,32 +1,38 @@
 # app/services/auth_service.py
 import logging
-from typing import Optional
 from uuid import UUID
 
-from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.core.auth import (
-    verify_password_async,
-    get_password_hash_async,
+    TokenExpiredError,
+    TokenInvalidError,
     create_access_token,
     create_refresh_token,
-    TokenExpiredError,
-    TokenInvalidError
+    get_password_hash_async,
+    verify_password_async,
 )
 from app.core.config import settings
-from app.core.exceptions import AuthenticationError
+from app.core.exceptions import AuthenticationError, DuplicateError
+from app.core.repository_exceptions import DuplicateEntryError
 from app.models.user import User
+from app.repositories.user import user_repo
 from app.schemas.users import Token, UserCreate, UserResponse
 
 logger = logging.getLogger(__name__)
 
+# Pre-computed bcrypt hash used for constant-time comparison when user is not found,
+# preventing timing attacks that could enumerate valid email addresses.
+_DUMMY_HASH = "$2b$12$EixZaYVK1fsbw1ZfbX3OXePaWxn96p36zLFbnJHfxPSEFBzXKiHia"
+
 
 class AuthService:
     """Service for handling authentication operations"""
 
     @staticmethod
-    async def authenticate_user(db: AsyncSession, email: str, password: str) -> Optional[User]:
+    async def authenticate_user(
+        db: AsyncSession, email: str, password: str
+    ) -> User | None:
         """
         Authenticate a user with email and password using async password verification.
 
@@ -38,10 +44,12 @@ class AuthService:
         Returns:
             User if authenticated, None otherwise
         """
-        result = await db.execute(select(User).where(User.email == email))
-        user = result.scalar_one_or_none()
+        user = await user_repo.get_by_email(db, email=email)
 
         if not user:
+            # Perform a dummy verification to match timing of a real bcrypt check,
+            # preventing email enumeration via response-time differences.
+            await verify_password_async(password, _DUMMY_HASH)
             return None
 
         # Verify password asynchronously to avoid blocking event loop
@@ -70,41 +78,24 @@ class AuthService:
         """
         try:
             # Check if user already exists
-            result = await db.execute(select(User).where(User.email == user_data.email))
-            existing_user = result.scalar_one_or_none()
+            existing_user = await user_repo.get_by_email(db, email=user_data.email)
             if existing_user:
-                raise AuthenticationError("User with this email already exists")
+                raise DuplicateError("User with this email already exists")
 
-            # Create new user with async password hashing
-            # Hash password asynchronously to avoid blocking event loop
-            hashed_password = await get_password_hash_async(user_data.password)
+            # Delegate creation (hashing + commit) to the repository
+            user = await user_repo.create(db, obj_in=user_data)
 
-            # Create user object from model
-            user = User(
-                email=user_data.email,
-                password_hash=hashed_password,
-                first_name=user_data.first_name,
-                last_name=user_data.last_name,
-                phone_number=user_data.phone_number,
-                is_active=True,
-                is_superuser=False
-            )
-
-            db.add(user)
-            await db.commit()
-            await db.refresh(user)
-
-            logger.info(f"User created successfully: {user.email}")
+            logger.info("User created successfully: %s", user.email)
             return user
 
-        except AuthenticationError:
-            # Re-raise authentication errors without rollback
+        except (AuthenticationError, DuplicateError):
+            # Re-raise API exceptions without rollback
             raise
+        except DuplicateEntryError as e:
+            raise DuplicateError(str(e))
         except Exception as e:
-            # Rollback on any database errors
-            await db.rollback()
-            logger.error(f"Error creating user: {str(e)}", exc_info=True)
-            raise AuthenticationError(f"Failed to create user: {str(e)}")
+            logger.exception("Error creating user: %s", e)
+            raise AuthenticationError(f"Failed to create user: {e!s}")
 
     @staticmethod
     def create_tokens(user: User) -> Token:
@@ -121,18 +112,13 @@ class AuthService:
         claims = {
             "is_superuser": user.is_superuser,
             "email": user.email,
-            "first_name": user.first_name
+            "first_name": user.first_name,
         }
 
         # Create tokens
-        access_token = create_access_token(
-            subject=str(user.id),
-            claims=claims
-        )
+        access_token = create_access_token(subject=str(user.id), claims=claims)
 
-        refresh_token = create_refresh_token(
-            subject=str(user.id)
-        )
+        refresh_token = create_refresh_token(subject=str(user.id))
 
         # Convert User model to UserResponse schema
         user_response = UserResponse.model_validate(user)
@@ -141,7 +127,8 @@ class AuthService:
             access_token=access_token,
             refresh_token=refresh_token,
             user=user_response,
-            expires_in=settings.ACCESS_TOKEN_EXPIRE_MINUTES * 60  # Convert minutes to seconds
+            expires_in=settings.ACCESS_TOKEN_EXPIRE_MINUTES
+            * 60,  # Convert minutes to seconds
         )
 
     @staticmethod
@@ -171,8 +158,7 @@ class AuthService:
             user_id = token_data.user_id
 
             # Get user from database
-            result = await db.execute(select(User).where(User.id == user_id))
-            user = result.scalar_one_or_none()
+            user = await user_repo.get(db, id=str(user_id))
             if not user or not user.is_active:
                 raise TokenInvalidError("Invalid user or inactive account")
 
@@ -180,11 +166,13 @@ class AuthService:
             return AuthService.create_tokens(user)
 
         except (TokenExpiredError, TokenInvalidError) as e:
-            logger.warning(f"Token refresh failed: {str(e)}")
+            logger.warning("Token refresh failed: %s", e)
             raise
 
     @staticmethod
-    async def change_password(db: AsyncSession, user_id: UUID, current_password: str, new_password: str) -> bool:
+    async def change_password(
+        db: AsyncSession, user_id: UUID, current_password: str, new_password: str
+    ) -> bool:
         """
         Change a user's password.
 
@@ -201,8 +189,7 @@ class AuthService:
             AuthenticationError: If current password is incorrect or update fails
         """
         try:
-            result = await db.execute(select(User).where(User.id == user_id))
-            user = result.scalar_one_or_none()
+            user = await user_repo.get(db, id=str(user_id))
             if not user:
                 raise AuthenticationError("User not found")
 
@@ -211,10 +198,10 @@ class AuthService:
                 raise AuthenticationError("Current password is incorrect")
 
             # Hash new password asynchronously to avoid blocking event loop
-            user.password_hash = await get_password_hash_async(new_password)
-            await db.commit()
+            new_hash = await get_password_hash_async(new_password)
+            await user_repo.update_password(db, user=user, password_hash=new_hash)
 
-            logger.info(f"Password changed successfully for user {user_id}")
+            logger.info("Password changed successfully for user %s", user_id)
             return True
 
         except AuthenticationError:
@@ -223,5 +210,34 @@ class AuthService:
         except Exception as e:
             # Rollback on any database errors
             await db.rollback()
-            logger.error(f"Error changing password for user {user_id}: {str(e)}", exc_info=True)
-            raise AuthenticationError(f"Failed to change password: {str(e)}")
+            logger.exception("Error changing password for user %s: %s", user_id, e)
+            raise AuthenticationError(f"Failed to change password: {e!s}")
+
+    @staticmethod
+    async def reset_password(
+        db: AsyncSession, *, email: str, new_password: str
+    ) -> User:
+        """
+        Reset a user's password without requiring the current password.
+
+        Args:
+            db: Database session
+            email: User email address
+            new_password: New password to set
+
+        Returns:
+            Updated user
+
+        Raises:
+            AuthenticationError: If user not found or inactive
+        """
+        user = await user_repo.get_by_email(db, email=email)
+        if not user:
+            raise AuthenticationError("User not found")
+        if not user.is_active:
+            raise AuthenticationError("User account is inactive")
+
+        new_hash = await get_password_hash_async(new_password)
+        user = await user_repo.update_password(db, user=user, password_hash=new_hash)
+        logger.info("Password reset successfully for %s", email)
+        return user

backend/app/services/email_service.py

@@ -5,9 +5,9 @@ Email service with placeholder implementation.
 This service provides email sending functionality with a simple console/log-based
 placeholder that can be easily replaced with a real email provider (SendGrid, SES, etc.)
 """
+
 import logging
 from abc import ABC, abstractmethod
-from typing import List, Optional
 
 from app.core.config import settings
 
@@ -20,13 +20,12 @@ class EmailBackend(ABC):
     @abstractmethod
     async def send_email(
         self,
-        to: List[str],
+        to: list[str],
         subject: str,
         html_content: str,
-        text_content: Optional[str] = None
+        text_content: str | None = None,
     ) -> bool:
         """Send an email."""
-        pass
 
 
 class ConsoleEmailBackend(EmailBackend):
@@ -39,10 +38,10 @@ class ConsoleEmailBackend(EmailBackend):
 
     async def send_email(
         self,
-        to: List[str],
+        to: list[str],
         subject: str,
         html_content: str,
-        text_content: Optional[str] = None
+        text_content: str | None = None,
     ) -> bool:
         """
         Log email content to console/logs.
@@ -59,8 +58,8 @@ class ConsoleEmailBackend(EmailBackend):
         logger.info("=" * 80)
         logger.info("EMAIL SENT (Console Backend)")
         logger.info("=" * 80)
-        logger.info(f"To: {', '.join(to)}")
-        logger.info(f"Subject: {subject}")
+        logger.info("To: %s", ", ".join(to))
+        logger.info("Subject: %s", subject)
         logger.info("-" * 80)
         if text_content:
             logger.info("Plain Text Content:")
@@ -88,10 +87,10 @@ class SMTPEmailBackend(EmailBackend):
 
     async def send_email(
         self,
-        to: List[str],
+        to: list[str],
         subject: str,
         html_content: str,
-        text_content: Optional[str] = None
+        text_content: str | None = None,
     ) -> bool:
         """Send email via SMTP."""
         # TODO: Implement SMTP sending
@@ -108,7 +107,7 @@ class EmailService:
     and can be configured to use different backends (console, SMTP, SendGrid, etc.)
     """
 
-    def __init__(self, backend: Optional[EmailBackend] = None):
+    def __init__(self, backend: EmailBackend | None = None):
         """
         Initialize email service with a backend.
 
@@ -118,10 +117,7 @@ class EmailService:
         self.backend = backend or ConsoleEmailBackend()
 
     async def send_password_reset_email(
-        self,
-        to_email: str,
-        reset_token: str,
-        user_name: Optional[str] = None
+        self, to_email: str, reset_token: str, user_name: str | None = None
     ) -> bool:
         """
         Send password reset email.
@@ -142,7 +138,7 @@ class EmailService:
 
         # Plain text version
         text_content = f"""
-Hello{' ' + user_name if user_name else ''},
+Hello{" " + user_name if user_name else ""},
 
 You requested a password reset for your account. Click the link below to reset your password:
 
@@ -177,7 +173,7 @@ The {settings.PROJECT_NAME} Team
             <h1>Password Reset</h1>
         </div>
         <div class="content">
-            <p>Hello{' ' + user_name if user_name else ''},</p>
+            <p>Hello{" " + user_name if user_name else ""},</p>
             <p>You requested a password reset for your account. Click the button below to reset your password:</p>
             <p style="text-align: center;">
                 <a href="{reset_url}" class="button">Reset Password</a>
@@ -200,17 +196,14 @@ The {settings.PROJECT_NAME} Team
                 to=[to_email],
                 subject=subject,
                 html_content=html_content,
-                text_content=text_content
+                text_content=text_content,
             )
         except Exception as e:
-            logger.error(f"Failed to send password reset email to {to_email}: {str(e)}")
+            logger.error("Failed to send password reset email to %s: %s", to_email, e)
             return False
 
     async def send_email_verification(
-        self,
-        to_email: str,
-        verification_token: str,
-        user_name: Optional[str] = None
+        self, to_email: str, verification_token: str, user_name: str | None = None
     ) -> bool:
         """
         Send email verification email.
@@ -224,14 +217,16 @@ The {settings.PROJECT_NAME} Team
             True if email sent successfully
         """
         # Generate verification URL
-        verification_url = f"{settings.FRONTEND_URL}/verify-email?token={verification_token}"
+        verification_url = (
+            f"{settings.FRONTEND_URL}/verify-email?token={verification_token}"
+        )
 
         # Prepare email content
         subject = "Verify Your Email Address"
 
         # Plain text version
         text_content = f"""
-Hello{' ' + user_name if user_name else ''},
+Hello{" " + user_name if user_name else ""},
 
 Thank you for signing up! Please verify your email address by clicking the link below:
 
@@ -266,7 +261,7 @@ The {settings.PROJECT_NAME} Team
             <h1>Verify Your Email</h1>
         </div>
         <div class="content">
-            <p>Hello{' ' + user_name if user_name else ''},</p>
+            <p>Hello{" " + user_name if user_name else ""},</p>
             <p>Thank you for signing up! Please verify your email address by clicking the button below:</p>
             <p style="text-align: center;">
                 <a href="{verification_url}" class="button">Verify Email</a>
@@ -289,10 +284,10 @@ The {settings.PROJECT_NAME} Team
                 to=[to_email],
                 subject=subject,
                 html_content=html_content,
-                text_content=text_content
+                text_content=text_content,
             )
         except Exception as e:
-            logger.error(f"Failed to send verification email to {to_email}: {str(e)}")
+            logger.error("Failed to send verification email to %s: %s", to_email, e)
             return False
 
 

backend/app/services/oauth_provider_service.py

@@ -0,0 +1,970 @@
+"""
+OAuth Provider Service for MCP integration.
+
+Implements OAuth 2.0 Authorization Server functionality:
+- Authorization code flow with PKCE
+- Token issuance (JWT access tokens, opaque refresh tokens)
+- Token refresh
+- Token revocation
+- Consent management
+
+Security features:
+- PKCE required for public clients (S256)
+- Short-lived authorization codes (10 minutes)
+- JWT access tokens (self-contained, no DB lookup)
+- Secure refresh token storage (hashed)
+- Token rotation on refresh
+- Comprehensive validation
+"""
+
+import base64
+import hashlib
+import logging
+import secrets
+from datetime import UTC, datetime, timedelta
+from typing import Any
+from uuid import UUID
+
+import jwt
+from jwt.exceptions import ExpiredSignatureError, InvalidTokenError
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.config import settings
+from app.models.oauth_client import OAuthClient
+from app.models.user import User
+from app.repositories.oauth_authorization_code import oauth_authorization_code_repo
+from app.repositories.oauth_client import oauth_client_repo
+from app.repositories.oauth_consent import oauth_consent_repo
+from app.repositories.oauth_provider_token import oauth_provider_token_repo
+from app.repositories.user import user_repo
+from app.schemas.oauth import OAuthClientCreate
+
+logger = logging.getLogger(__name__)
+
+# Constants
+AUTHORIZATION_CODE_EXPIRY_MINUTES = 10
+ACCESS_TOKEN_EXPIRY_MINUTES = 60  # 1 hour for MCP clients
+REFRESH_TOKEN_EXPIRY_DAYS = 30
+
+
+class OAuthProviderError(Exception):
+    """Base exception for OAuth provider errors."""
+
+    def __init__(
+        self,
+        error: str,
+        error_description: str | None = None,
+        error_uri: str | None = None,
+    ):
+        self.error = error
+        self.error_description = error_description
+        self.error_uri = error_uri
+        super().__init__(error_description or error)
+
+
+class InvalidClientError(OAuthProviderError):
+    """Client authentication failed."""
+
+    def __init__(self, description: str = "Invalid client credentials"):
+        super().__init__("invalid_client", description)
+
+
+class InvalidGrantError(OAuthProviderError):
+    """Invalid authorization grant."""
+
+    def __init__(self, description: str = "Invalid grant"):
+        super().__init__("invalid_grant", description)
+
+
+class InvalidRequestError(OAuthProviderError):
+    """Invalid request parameters."""
+
+    def __init__(self, description: str = "Invalid request"):
+        super().__init__("invalid_request", description)
+
+
+class InvalidScopeError(OAuthProviderError):
+    """Invalid scope requested."""
+
+    def __init__(self, description: str = "Invalid scope"):
+        super().__init__("invalid_scope", description)
+
+
+class UnauthorizedClientError(OAuthProviderError):
+    """Client not authorized for this grant type."""
+
+    def __init__(self, description: str = "Unauthorized client"):
+        super().__init__("unauthorized_client", description)
+
+
+class AccessDeniedError(OAuthProviderError):
+    """User denied authorization."""
+
+    def __init__(self, description: str = "Access denied"):
+        super().__init__("access_denied", description)
+
+
+# ============================================================================
+# Helper Functions
+# ============================================================================
+
+
+def generate_code() -> str:
+    """Generate a cryptographically secure authorization code."""
+    return secrets.token_urlsafe(64)
+
+
+def generate_token() -> str:
+    """Generate a cryptographically secure token."""
+    return secrets.token_urlsafe(48)
+
+
+def generate_jti() -> str:
+    """Generate a unique JWT ID."""
+    return secrets.token_urlsafe(32)
+
+
+def hash_token(token: str) -> str:
+    """Hash a token using SHA-256."""
+    return hashlib.sha256(token.encode()).hexdigest()
+
+
+def verify_pkce(code_verifier: str, code_challenge: str, method: str) -> bool:
+    """
+    Verify PKCE code_verifier against stored code_challenge.
+
+    SECURITY: Only S256 method is supported. The 'plain' method provides
+    no security benefit and is explicitly rejected per RFC 7636 Section 4.3.
+    """
+    if method != "S256":
+        # SECURITY: Reject any method other than S256
+        # 'plain' method provides no security against code interception attacks
+        logger.warning("PKCE verification rejected for unsupported method: %s", method)
+        return False
+
+    # SHA-256 hash, then base64url encode (RFC 7636 Section 4.2)
+    digest = hashlib.sha256(code_verifier.encode()).digest()
+    computed = base64.urlsafe_b64encode(digest).rstrip(b"=").decode()
+    return secrets.compare_digest(computed, code_challenge)
+
+
+def parse_scope(scope: str) -> list[str]:
+    """Parse space-separated scope string into list."""
+    return [s.strip() for s in scope.split() if s.strip()]
+
+
+def join_scope(scopes: list[str]) -> str:
+    """Join scope list into space-separated string."""
+    return " ".join(sorted(set(scopes)))
+
+
+# ============================================================================
+# Client Validation
+# ============================================================================
+
+
+async def get_client(db: AsyncSession, client_id: str) -> OAuthClient | None:
+    """Get OAuth client by client_id."""
+    return await oauth_client_repo.get_by_client_id(db, client_id=client_id)
+
+
+async def validate_client(
+    db: AsyncSession,
+    client_id: str,
+    client_secret: str | None = None,
+    require_secret: bool = False,
+) -> OAuthClient:
+    """
+    Validate OAuth client credentials.
+
+    Args:
+        db: Database session
+        client_id: Client identifier
+        client_secret: Client secret (required for confidential clients)
+        require_secret: Whether to require secret validation
+
+    Returns:
+        Validated OAuthClient
+
+    Raises:
+        InvalidClientError: If client validation fails
+    """
+    client = await get_client(db, client_id)
+    if not client:
+        raise InvalidClientError("Unknown client_id")
+
+    # Confidential clients must provide valid secret
+    if client.client_type == "confidential" or require_secret:
+        if not client_secret:
+            raise InvalidClientError("Client secret required")
+        if not client.client_secret_hash:
+            raise InvalidClientError("Client not configured with secret")
+
+        # SECURITY: Verify secret using bcrypt
+        from app.core.auth import verify_password
+
+        stored_hash = str(client.client_secret_hash)
+
+        if not stored_hash.startswith("$2"):
+            raise InvalidClientError(
+                "Client secret uses deprecated hash format. "
+                "Please regenerate your client credentials."
+            )
+
+        if not verify_password(client_secret, stored_hash):
+            raise InvalidClientError("Invalid client secret")
+
+    return client
+
+
+def validate_redirect_uri(client: OAuthClient, redirect_uri: str) -> None:
+    """
+    Validate redirect_uri against client's registered URIs.
+
+    Raises:
+        InvalidRequestError: If redirect_uri is not registered
+    """
+    if not client.redirect_uris:
+        raise InvalidRequestError("Client has no registered redirect URIs")
+
+    if redirect_uri not in client.redirect_uris:
+        raise InvalidRequestError("Invalid redirect_uri")
+
+
+def validate_scopes(client: OAuthClient, requested_scopes: list[str]) -> list[str]:
+    """
+    Validate requested scopes against client's allowed scopes.
+
+    Returns:
+        List of valid scopes (intersection of requested and allowed)
+
+    Raises:
+        InvalidScopeError: If no valid scopes
+    """
+    allowed = set(client.allowed_scopes or [])
+    requested = set(requested_scopes)
+
+    # If no scopes requested, use all allowed scopes
+    if not requested:
+        return list(allowed)
+
+    valid = requested & allowed
+    if not valid:
+        raise InvalidScopeError(
+            "None of the requested scopes are allowed for this client"
+        )
+
+    # Warn if some scopes were filtered out
+    invalid = requested - allowed
+    if invalid:
+        logger.warning(
+            "Client %s requested invalid scopes: %s", client.client_id, invalid
+        )
+
+    return list(valid)
+
+
+# ============================================================================
+# Authorization Code Flow
+# ============================================================================
+
+
+async def create_authorization_code(
+    db: AsyncSession,
+    client: OAuthClient,
+    user: User,
+    redirect_uri: str,
+    scope: str,
+    code_challenge: str | None = None,
+    code_challenge_method: str | None = None,
+    state: str | None = None,
+    nonce: str | None = None,
+) -> str:
+    """
+    Create an authorization code for the authorization code flow.
+
+    Args:
+        db: Database session
+        client: Validated OAuth client
+        user: Authenticated user
+        redirect_uri: Validated redirect URI
+        scope: Granted scopes (space-separated)
+        code_challenge: PKCE code challenge
+        code_challenge_method: PKCE method (S256)
+        state: CSRF state parameter
+        nonce: OpenID Connect nonce
+
+    Returns:
+        Authorization code string
+    """
+    # Public clients MUST use PKCE
+    if client.client_type == "public":
+        if not code_challenge or code_challenge_method != "S256":
+            raise InvalidRequestError("PKCE with S256 is required for public clients")
+
+    code = generate_code()
+    expires_at = datetime.now(UTC) + timedelta(
+        minutes=AUTHORIZATION_CODE_EXPIRY_MINUTES
+    )
+
+    await oauth_authorization_code_repo.create_code(
+        db,
+        code=code,
+        client_id=client.client_id,
+        user_id=user.id,
+        redirect_uri=redirect_uri,
+        scope=scope,
+        expires_at=expires_at,
+        code_challenge=code_challenge,
+        code_challenge_method=code_challenge_method,
+        state=state,
+        nonce=nonce,
+    )
+
+    logger.info(
+        "Created authorization code for user %s and client %s",
+        user.id,
+        client.client_id,
+    )
+    return code
+
+
+async def exchange_authorization_code(
+    db: AsyncSession,
+    code: str,
+    client_id: str,
+    redirect_uri: str,
+    code_verifier: str | None = None,
+    client_secret: str | None = None,
+    device_info: str | None = None,
+    ip_address: str | None = None,
+) -> dict[str, Any]:
+    """
+    Exchange authorization code for tokens.
+
+    Args:
+        db: Database session
+        code: Authorization code
+        client_id: Client identifier
+        redirect_uri: Must match the original redirect_uri
+        code_verifier: PKCE code verifier
+        client_secret: Client secret (for confidential clients)
+        device_info: Optional device information
+        ip_address: Optional IP address
+
+    Returns:
+        Token response dict with access_token, refresh_token, etc.
+
+    Raises:
+        InvalidGrantError: If code is invalid, expired, or already used
+        InvalidClientError: If client validation fails
+    """
+    # Atomically mark code as used and fetch it (prevents race condition)
+    # RFC 6749 Section 4.1.2: Authorization codes MUST be single-use
+    updated_id = await oauth_authorization_code_repo.consume_code_atomically(
+        db, code=code
+    )
+
+    if not updated_id:
+        # Either code doesn't exist or was already used
+        # Check if it exists to provide appropriate error
+        existing_code = await oauth_authorization_code_repo.get_by_code(db, code=code)
+
+        if existing_code and existing_code.used:
+            # Code reuse is a security incident - revoke all tokens for this grant
+            logger.warning(
+                "Authorization code reuse detected for client %s",
+                existing_code.client_id,
+            )
+            await revoke_tokens_for_user_client(
+                db, UUID(str(existing_code.user_id)), str(existing_code.client_id)
+            )
+            raise InvalidGrantError("Authorization code has already been used")
+        else:
+            raise InvalidGrantError("Invalid authorization code")
+
+    # Now fetch the full auth code record
+    auth_code = await oauth_authorization_code_repo.get_by_id(db, code_id=updated_id)
+    if auth_code is None:
+        raise InvalidGrantError("Authorization code not found after consumption")
+
+    if auth_code.is_expired:
+        raise InvalidGrantError("Authorization code has expired")
+
+    if auth_code.client_id != client_id:
+        raise InvalidGrantError("Authorization code was not issued to this client")
+
+    if auth_code.redirect_uri != redirect_uri:
+        raise InvalidGrantError("redirect_uri mismatch")
+
+    # Validate client - ALWAYS require secret for confidential clients
+    client = await get_client(db, client_id)
+    if not client:
+        raise InvalidClientError("Unknown client_id")
+
+    # Confidential clients MUST authenticate (RFC 6749 Section 3.2.1)
+    if client.client_type == "confidential":
+        if not client_secret:
+            raise InvalidClientError("Client secret required for confidential clients")
+        client = await validate_client(
+            db, client_id, client_secret, require_secret=True
+        )
+    elif client_secret:
+        # Public client provided secret - validate it if given
+        client = await validate_client(
+            db, client_id, client_secret, require_secret=True
+        )
+
+    # Verify PKCE
+    if auth_code.code_challenge:
+        if not code_verifier:
+            raise InvalidGrantError("code_verifier required")
+        if not verify_pkce(
+            code_verifier,
+            str(auth_code.code_challenge),
+            str(auth_code.code_challenge_method or "S256"),
+        ):
+            raise InvalidGrantError("Invalid code_verifier")
+    elif client.client_type == "public":
+        # Public clients without PKCE - this shouldn't happen if we validated on authorize
+        raise InvalidGrantError("PKCE required for public clients")
+
+    # Get user
+    user = await user_repo.get(db, id=str(auth_code.user_id))
+    if not user or not user.is_active:
+        raise InvalidGrantError("User not found or inactive")
+
+    # Generate tokens
+    return await create_tokens(
+        db=db,
+        client=client,
+        user=user,
+        scope=str(auth_code.scope),
+        nonce=str(auth_code.nonce) if auth_code.nonce else None,
+        device_info=device_info,
+        ip_address=ip_address,
+    )
+
+
+# ============================================================================
+# Token Generation
+# ============================================================================
+
+
+async def create_tokens(
+    db: AsyncSession,
+    client: OAuthClient,
+    user: User,
+    scope: str,
+    nonce: str | None = None,
+    device_info: str | None = None,
+    ip_address: str | None = None,
+) -> dict[str, Any]:
+    """
+    Create access and refresh tokens.
+
+    Args:
+        db: Database session
+        client: OAuth client
+        user: User
+        scope: Granted scopes
+        nonce: OpenID Connect nonce (included in ID token)
+        device_info: Optional device information
+        ip_address: Optional IP address
+
+    Returns:
+        Token response dict
+    """
+    now = datetime.now(UTC)
+    jti = generate_jti()
+
+    # Access token expiry
+    access_token_lifetime = int(client.access_token_lifetime or "3600")
+    access_expires = now + timedelta(seconds=access_token_lifetime)
+
+    # Refresh token expiry
+    refresh_token_lifetime = int(
+        client.refresh_token_lifetime or str(REFRESH_TOKEN_EXPIRY_DAYS * 86400)
+    )
+    refresh_expires = now + timedelta(seconds=refresh_token_lifetime)
+
+    # Create JWT access token
+    # SECURITY: Include all standard JWT claims per RFC 7519
+    access_token_payload = {
+        "iss": settings.OAUTH_ISSUER,
+        "sub": str(user.id),
+        "aud": client.client_id,
+        "exp": int(access_expires.timestamp()),
+        "iat": int(now.timestamp()),
+        "nbf": int(now.timestamp()),  # Not Before - token is valid immediately
+        "jti": jti,
+        "scope": scope,
+        "client_id": client.client_id,
+        # User info (basic claims)
+        "email": user.email,
+        "name": f"{user.first_name or ''} {user.last_name or ''}".strip() or user.email,
+    }
+
+    # Add nonce for OpenID Connect
+    if nonce:
+        access_token_payload["nonce"] = nonce
+
+    access_token = jwt.encode(
+        access_token_payload,
+        settings.SECRET_KEY,
+        algorithm=settings.ALGORITHM,
+    )
+
+    # Create opaque refresh token
+    refresh_token = generate_token()
+    refresh_token_hash = hash_token(refresh_token)
+
+    # Store refresh token in database
+    await oauth_provider_token_repo.create_token(
+        db,
+        token_hash=refresh_token_hash,
+        jti=jti,
+        client_id=client.client_id,
+        user_id=user.id,
+        scope=scope,
+        expires_at=refresh_expires,
+        device_info=device_info,
+        ip_address=ip_address,
+    )
+
+    logger.info("Issued tokens for user %s to client %s", user.id, client.client_id)
+
+    return {
+        "access_token": access_token,
+        "token_type": "Bearer",
+        "expires_in": access_token_lifetime,
+        "refresh_token": refresh_token,
+        "scope": scope,
+    }
+
+
+async def refresh_tokens(
+    db: AsyncSession,
+    refresh_token: str,
+    client_id: str,
+    client_secret: str | None = None,
+    scope: str | None = None,
+    device_info: str | None = None,
+    ip_address: str | None = None,
+) -> dict[str, Any]:
+    """
+    Refresh access token using refresh token.
+
+    Implements token rotation - old refresh token is invalidated,
+    new refresh token is issued.
+
+    Args:
+        db: Database session
+        refresh_token: Refresh token
+        client_id: Client identifier
+        client_secret: Client secret (for confidential clients)
+        scope: Optional reduced scope
+        device_info: Optional device information
+        ip_address: Optional IP address
+
+    Returns:
+        New token response dict
+
+    Raises:
+        InvalidGrantError: If refresh token is invalid
+    """
+    # Find refresh token
+    token_hash = hash_token(refresh_token)
+    token_record = await oauth_provider_token_repo.get_by_token_hash(
+        db, token_hash=token_hash
+    )
+
+    if not token_record:
+        raise InvalidGrantError("Invalid refresh token")
+
+    if token_record.revoked:
+        # Token reuse after revocation - security incident
+        logger.warning(
+            "Revoked refresh token reuse detected for client %s", token_record.client_id
+        )
+        raise InvalidGrantError("Refresh token has been revoked")
+
+    if token_record.is_expired:
+        raise InvalidGrantError("Refresh token has expired")
+
+    if token_record.client_id != client_id:
+        raise InvalidGrantError("Refresh token was not issued to this client")
+
+    # Validate client
+    client = await validate_client(
+        db,
+        client_id,
+        client_secret,
+        require_secret=(client_secret is not None),
+    )
+
+    # Get user
+    user = await user_repo.get(db, id=str(token_record.user_id))
+    if not user or not user.is_active:
+        raise InvalidGrantError("User not found or inactive")
+
+    # Validate scope (can only reduce, not expand)
+    token_scope = str(token_record.scope) if token_record.scope else ""
+    original_scopes = set(parse_scope(token_scope))
+    if scope:
+        requested_scopes = set(parse_scope(scope))
+        if not requested_scopes.issubset(original_scopes):
+            raise InvalidScopeError("Cannot expand scope on refresh")
+        final_scope = join_scope(list(requested_scopes))
+    else:
+        final_scope = token_scope
+
+    # Revoke old refresh token (token rotation)
+    await oauth_provider_token_repo.revoke(db, token=token_record)
+
+    # Issue new tokens
+    device = str(token_record.device_info) if token_record.device_info else None
+    ip_addr = str(token_record.ip_address) if token_record.ip_address else None
+    return await create_tokens(
+        db=db,
+        client=client,
+        user=user,
+        scope=final_scope,
+        device_info=device_info or device,
+        ip_address=ip_address or ip_addr,
+    )
+
+
+# ============================================================================
+# Token Revocation
+# ============================================================================
+
+
+async def revoke_token(
+    db: AsyncSession,
+    token: str,
+    token_type_hint: str | None = None,
+    client_id: str | None = None,
+    client_secret: str | None = None,
+) -> bool:
+    """
+    Revoke a token (access or refresh).
+
+    For refresh tokens: marks as revoked in database
+    For access tokens: we can't truly revoke JWTs, but we can revoke
+    the associated refresh token to prevent further refreshes
+
+    Args:
+        db: Database session
+        token: Token to revoke
+        token_type_hint: "access_token" or "refresh_token"
+        client_id: Client identifier (for validation)
+        client_secret: Client secret (for confidential clients)
+
+    Returns:
+        True if token was revoked, False if not found
+    """
+    # Try as refresh token first (more likely)
+    if token_type_hint != "access_token":
+        token_hash = hash_token(token)
+        refresh_record = await oauth_provider_token_repo.get_by_token_hash(
+            db, token_hash=token_hash
+        )
+
+        if refresh_record:
+            # Validate client if provided
+            if client_id and refresh_record.client_id != client_id:
+                raise InvalidClientError("Token was not issued to this client")
+
+            await oauth_provider_token_repo.revoke(db, token=refresh_record)
+            logger.info("Revoked refresh token %s...", refresh_record.jti[:8])
+            return True
+
+    # Try as access token (JWT)
+    if token_type_hint != "refresh_token":
+        try:
+            payload = jwt.decode(
+                token,
+                settings.SECRET_KEY,
+                algorithms=[settings.ALGORITHM],
+                options={
+                    "verify_exp": False,
+                    "verify_aud": False,
+                },  # Allow expired tokens
+            )
+            jti = payload.get("jti")
+            if jti:
+                # Find and revoke the associated refresh token
+                refresh_record = await oauth_provider_token_repo.get_by_jti(db, jti=jti)
+                if refresh_record:
+                    if client_id and refresh_record.client_id != client_id:
+                        raise InvalidClientError("Token was not issued to this client")
+                    await oauth_provider_token_repo.revoke(db, token=refresh_record)
+                    logger.info(
+                        "Revoked refresh token via access token JTI %s...", jti[:8]
+                    )
+                    return True
+        except InvalidTokenError:
+            pass
+        except Exception:  # noqa: S110 - Intentional: invalid JWT not an error
+            pass
+
+    return False
+
+
+async def revoke_tokens_for_user_client(
+    db: AsyncSession,
+    user_id: UUID,
+    client_id: str,
+) -> int:
+    """
+    Revoke all tokens for a specific user-client pair.
+
+    Used when security incidents are detected (e.g., code reuse).
+
+    Args:
+        db: Database session
+        user_id: User identifier
+        client_id: Client identifier
+
+    Returns:
+        Number of tokens revoked
+    """
+    count = await oauth_provider_token_repo.revoke_all_for_user_client(
+        db, user_id=user_id, client_id=client_id
+    )
+
+    if count > 0:
+        logger.warning(
+            "Revoked %s tokens for user %s and client %s", count, user_id, client_id
+        )
+
+    return count
+
+
+async def revoke_all_user_tokens(db: AsyncSession, user_id: UUID) -> int:
+    """
+    Revoke all OAuth provider tokens for a user.
+
+    Used when user changes password or explicitly logs out everywhere.
+
+    Args:
+        db: Database session
+        user_id: User identifier
+
+    Returns:
+        Number of tokens revoked
+    """
+    count = await oauth_provider_token_repo.revoke_all_for_user(db, user_id=user_id)
+
+    if count > 0:
+        logger.info("Revoked %s OAuth provider tokens for user %s", count, user_id)
+
+    return count
+
+
+# ============================================================================
+# Token Introspection (RFC 7662)
+# ============================================================================
+
+
+async def introspect_token(
+    db: AsyncSession,
+    token: str,
+    token_type_hint: str | None = None,
+    client_id: str | None = None,
+    client_secret: str | None = None,
+) -> dict[str, Any]:
+    """
+    Introspect a token to determine its validity and metadata.
+
+    Implements RFC 7662 Token Introspection.
+
+    Args:
+        db: Database session
+        token: Token to introspect
+        token_type_hint: "access_token" or "refresh_token"
+        client_id: Client requesting introspection
+        client_secret: Client secret
+
+    Returns:
+        Introspection response dict
+    """
+    # Validate client if credentials provided
+    if client_id:
+        await validate_client(db, client_id, client_secret)
+
+    # Try as access token (JWT) first
+    if token_type_hint != "refresh_token":
+        try:
+            payload = jwt.decode(
+                token,
+                settings.SECRET_KEY,
+                algorithms=[settings.ALGORITHM],
+                options={
+                    "verify_aud": False
+                },  # Don't require audience match for introspection
+            )
+
+            # Check if associated refresh token is revoked
+            jti = payload.get("jti")
+            if jti:
+                refresh_record = await oauth_provider_token_repo.get_by_jti(db, jti=jti)
+                if refresh_record and refresh_record.revoked:
+                    return {"active": False}
+
+            return {
+                "active": True,
+                "scope": payload.get("scope", ""),
+                "client_id": payload.get("client_id"),
+                "username": payload.get("email"),
+                "token_type": "Bearer",
+                "exp": payload.get("exp"),
+                "iat": payload.get("iat"),
+                "sub": payload.get("sub"),
+                "aud": payload.get("aud"),
+                "iss": payload.get("iss"),
+            }
+        except ExpiredSignatureError:
+            return {"active": False}
+        except InvalidTokenError:
+            pass
+        except Exception:  # noqa: S110 - Intentional: invalid JWT falls through to refresh token check
+            pass
+
+    # Try as refresh token
+    if token_type_hint != "access_token":
+        token_hash = hash_token(token)
+        refresh_record = await oauth_provider_token_repo.get_by_token_hash(
+            db, token_hash=token_hash
+        )
+
+        if refresh_record and refresh_record.is_valid:
+            return {
+                "active": True,
+                "scope": refresh_record.scope,
+                "client_id": refresh_record.client_id,
+                "token_type": "refresh_token",
+                "exp": int(refresh_record.expires_at.timestamp()),
+                "iat": int(refresh_record.created_at.timestamp()),
+                "sub": str(refresh_record.user_id),
+            }
+
+    return {"active": False}
+
+
+# ============================================================================
+# Consent Management
+# ============================================================================
+
+
+async def get_consent(
+    db: AsyncSession,
+    user_id: UUID,
+    client_id: str,
+):
+    """Get existing consent record for user-client pair."""
+    return await oauth_consent_repo.get_consent(
+        db, user_id=user_id, client_id=client_id
+    )
+
+
+async def check_consent(
+    db: AsyncSession,
+    user_id: UUID,
+    client_id: str,
+    requested_scopes: list[str],
+) -> bool:
+    """
+    Check if user has already consented to the requested scopes.
+
+    Returns True if all requested scopes are already granted.
+    """
+    consent = await get_consent(db, user_id, client_id)
+    if not consent:
+        return False
+    return consent.has_scopes(requested_scopes)
+
+
+async def grant_consent(
+    db: AsyncSession,
+    user_id: UUID,
+    client_id: str,
+    scopes: list[str],
+):
+    """
+    Grant or update consent for a user-client pair.
+
+    If consent already exists, updates the granted scopes.
+    """
+    return await oauth_consent_repo.grant_consent(
+        db, user_id=user_id, client_id=client_id, scopes=scopes
+    )
+
+
+async def revoke_consent(
+    db: AsyncSession,
+    user_id: UUID,
+    client_id: str,
+) -> bool:
+    """
+    Revoke consent and all tokens for a user-client pair.
+
+    Returns True if consent was found and revoked.
+    """
+    # Revoke all tokens first
+    await revoke_tokens_for_user_client(db, user_id, client_id)
+
+    # Delete consent record
+    return await oauth_consent_repo.revoke_consent(
+        db, user_id=user_id, client_id=client_id
+    )
+
+
+# ============================================================================
+# Cleanup
+# ============================================================================
+
+
+async def register_client(db: AsyncSession, client_data: OAuthClientCreate) -> tuple:
+    """Create a new OAuth client. Returns (client, secret)."""
+    return await oauth_client_repo.create_client(db, obj_in=client_data)
+
+
+async def list_clients(db: AsyncSession) -> list:
+    """List all registered OAuth clients."""
+    return await oauth_client_repo.get_all_clients(db)
+
+
+async def delete_client_by_id(db: AsyncSession, client_id: str) -> None:
+    """Delete an OAuth client by client_id."""
+    await oauth_client_repo.delete_client(db, client_id=client_id)
+
+
+async def list_user_consents(db: AsyncSession, user_id: UUID) -> list[dict]:
+    """Get all OAuth consents for a user with client details."""
+    return await oauth_consent_repo.get_user_consents_with_clients(db, user_id=user_id)
+
+
+async def cleanup_expired_codes(db: AsyncSession) -> int:
+    """
+    Delete expired authorization codes.
+
+    Should be called periodically (e.g., every hour).
+
+    Returns:
+        Number of codes deleted
+    """
+    return await oauth_authorization_code_repo.cleanup_expired(db)
+
+
+async def cleanup_expired_tokens(db: AsyncSession) -> int:
+    """
+    Delete expired and revoked refresh tokens.
+
+    Should be called periodically (e.g., daily).
+
+    Returns:
+        Number of tokens deleted
+    """
+    return await oauth_provider_token_repo.cleanup_expired(db, cutoff_days=7)

backend/app/services/oauth_service.py

@@ -0,0 +1,744 @@
+"""
+OAuth Service for handling social authentication flows.
+
+Supports:
+- Google OAuth (OpenID Connect)
+- GitHub OAuth
+
+Features:
+- PKCE support for public clients
+- State parameter for CSRF protection
+- Auto-linking by email (configurable)
+- Account linking for existing users
+"""
+
+import logging
+import secrets
+from datetime import UTC, datetime, timedelta
+from typing import TypedDict, cast
+from uuid import UUID
+
+from authlib.integrations.httpx_client import AsyncOAuth2Client
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.auth import create_access_token, create_refresh_token
+from app.core.config import settings
+from app.core.exceptions import AuthenticationError
+from app.models.user import User
+from app.repositories.oauth_account import oauth_account_repo as oauth_account
+from app.repositories.oauth_state import oauth_state_repo as oauth_state
+from app.repositories.user import user_repo
+from app.schemas.oauth import (
+    OAuthAccountCreate,
+    OAuthCallbackResponse,
+    OAuthProviderInfo,
+    OAuthProvidersResponse,
+    OAuthStateCreate,
+)
+
+logger = logging.getLogger(__name__)
+
+
+class _OAuthProviderConfigRequired(TypedDict):
+    name: str
+    icon: str
+    authorize_url: str
+    token_url: str
+    userinfo_url: str
+    scopes: list[str]
+    supports_pkce: bool
+
+
+class OAuthProviderConfig(_OAuthProviderConfigRequired, total=False):
+    """Type definition for OAuth provider configuration."""
+
+    email_url: str  # Optional, GitHub-only
+
+
+# Provider configurations
+OAUTH_PROVIDERS: dict[str, OAuthProviderConfig] = {
+    "google": {
+        "name": "Google",
+        "icon": "google",
+        "authorize_url": "https://accounts.google.com/o/oauth2/v2/auth",
+        "token_url": "https://oauth2.googleapis.com/token",
+        "userinfo_url": "https://www.googleapis.com/oauth2/v3/userinfo",
+        "scopes": ["openid", "email", "profile"],
+        "supports_pkce": True,
+    },
+    "github": {
+        "name": "GitHub",
+        "icon": "github",
+        "authorize_url": "https://github.com/login/oauth/authorize",
+        "token_url": "https://github.com/login/oauth/access_token",
+        "userinfo_url": "https://api.github.com/user",
+        "email_url": "https://api.github.com/user/emails",
+        "scopes": ["read:user", "user:email"],
+        "supports_pkce": False,  # GitHub doesn't support PKCE
+    },
+}
+
+
+class OAuthService:
+    """Service for handling OAuth authentication flows."""
+
+    @staticmethod
+    def get_enabled_providers() -> OAuthProvidersResponse:
+        """
+        Get list of enabled OAuth providers.
+
+        Returns:
+            OAuthProvidersResponse with enabled providers
+        """
+        providers = []
+
+        for provider_id in settings.enabled_oauth_providers:
+            if provider_id in OAUTH_PROVIDERS:
+                config = OAUTH_PROVIDERS[provider_id]
+                providers.append(
+                    OAuthProviderInfo(
+                        provider=provider_id,
+                        name=config["name"],
+                        icon=config["icon"],
+                    )
+                )
+
+        return OAuthProvidersResponse(
+            enabled=settings.OAUTH_ENABLED and len(providers) > 0,
+            providers=providers,
+        )
+
+    @staticmethod
+    def _get_provider_credentials(provider: str) -> tuple[str, str]:
+        """Get client ID and secret for a provider."""
+        if provider == "google":
+            client_id = settings.OAUTH_GOOGLE_CLIENT_ID
+            client_secret = settings.OAUTH_GOOGLE_CLIENT_SECRET
+        elif provider == "github":
+            client_id = settings.OAUTH_GITHUB_CLIENT_ID
+            client_secret = settings.OAUTH_GITHUB_CLIENT_SECRET
+        else:
+            raise AuthenticationError(f"Unknown OAuth provider: {provider}")
+
+        if not client_id or not client_secret:
+            raise AuthenticationError(f"OAuth provider {provider} is not configured")
+
+        return client_id, client_secret
+
+    @staticmethod
+    async def create_authorization_url(
+        db: AsyncSession,
+        *,
+        provider: str,
+        redirect_uri: str,
+        user_id: str | None = None,
+    ) -> tuple[str, str]:
+        """
+        Create OAuth authorization URL with state and optional PKCE.
+
+        Args:
+            db: Database session
+            provider: OAuth provider (google, github)
+            redirect_uri: Callback URL after OAuth
+            user_id: User ID if linking account (user is logged in)
+
+        Returns:
+            Tuple of (authorization_url, state)
+
+        Raises:
+            AuthenticationError: If provider is not configured
+        """
+        if not settings.OAUTH_ENABLED:
+            raise AuthenticationError("OAuth is not enabled")
+
+        if provider not in OAUTH_PROVIDERS:
+            raise AuthenticationError(f"Unknown OAuth provider: {provider}")
+
+        if provider not in settings.enabled_oauth_providers:
+            raise AuthenticationError(f"OAuth provider {provider} is not enabled")
+
+        config = OAUTH_PROVIDERS[provider]
+        client_id, client_secret = OAuthService._get_provider_credentials(provider)
+
+        # Generate state for CSRF protection
+        state = secrets.token_urlsafe(32)
+
+        # Generate PKCE code verifier and challenge if supported
+        code_verifier = None
+        code_challenge = None
+        if config.get("supports_pkce"):
+            code_verifier = secrets.token_urlsafe(64)
+            # Create code_challenge using S256 method
+            import base64
+            import hashlib
+
+            code_challenge_bytes = hashlib.sha256(code_verifier.encode()).digest()
+            code_challenge = (
+                base64.urlsafe_b64encode(code_challenge_bytes).decode().rstrip("=")
+            )
+
+        # Generate nonce for OIDC (Google)
+        nonce = secrets.token_urlsafe(32) if provider == "google" else None
+
+        # Store state in database
+        from uuid import UUID
+
+        state_data = OAuthStateCreate(
+            state=state,
+            code_verifier=code_verifier,
+            nonce=nonce,
+            provider=provider,
+            redirect_uri=redirect_uri,
+            user_id=UUID(user_id) if user_id else None,
+            expires_at=datetime.now(UTC)
+            + timedelta(minutes=settings.OAUTH_STATE_EXPIRE_MINUTES),
+        )
+        await oauth_state.create_state(db, obj_in=state_data)
+
+        # Build authorization URL
+        async with AsyncOAuth2Client(
+            client_id=client_id,
+            client_secret=client_secret,
+            redirect_uri=redirect_uri,
+        ) as client:
+            # Prepare authorization params
+            auth_params = {
+                "state": state,
+                "scope": " ".join(config["scopes"]),
+            }
+
+            if code_challenge:
+                auth_params["code_challenge"] = code_challenge
+                auth_params["code_challenge_method"] = "S256"
+
+            if nonce:
+                auth_params["nonce"] = nonce
+
+            url, _ = client.create_authorization_url(
+                config["authorize_url"],
+                **auth_params,
+            )
+
+        logger.info("OAuth authorization URL created for %s", provider)
+        return url, state
+
+    @staticmethod
+    async def handle_callback(
+        db: AsyncSession,
+        *,
+        code: str,
+        state: str,
+        redirect_uri: str,
+    ) -> OAuthCallbackResponse:
+        """
+        Handle OAuth callback and authenticate/create user.
+
+        Args:
+            db: Database session
+            code: Authorization code from provider
+            state: State parameter for CSRF verification
+            redirect_uri: Callback URL (must match authorization request)
+
+        Returns:
+            OAuthCallbackResponse with tokens
+
+        Raises:
+            AuthenticationError: If authentication fails
+        """
+        # Validate and consume state
+        state_record = await oauth_state.get_and_consume_state(db, state=state)
+        if not state_record:
+            raise AuthenticationError("Invalid or expired OAuth state")
+
+        # SECURITY: Validate redirect_uri matches the one from authorization request
+        # This prevents authorization code injection attacks (RFC 6749 Section 10.6)
+        if state_record.redirect_uri != redirect_uri:
+            logger.warning(
+                "OAuth redirect_uri mismatch: expected %s, got %s",
+                state_record.redirect_uri,
+                redirect_uri,
+            )
+            raise AuthenticationError("Redirect URI mismatch")
+
+        # Extract provider from state record (str for type safety)
+        provider: str = str(state_record.provider)
+
+        if provider not in OAUTH_PROVIDERS:
+            raise AuthenticationError(f"Unknown OAuth provider: {provider}")
+
+        config = OAUTH_PROVIDERS[provider]
+        client_id, client_secret = OAuthService._get_provider_credentials(provider)
+
+        # Exchange code for tokens
+        async with AsyncOAuth2Client(
+            client_id=client_id,
+            client_secret=client_secret,
+            redirect_uri=redirect_uri,
+        ) as client:
+            try:
+                # Prepare token request params
+                token_params: dict[str, str] = {"code": code}
+
+                if state_record.code_verifier:
+                    token_params["code_verifier"] = str(state_record.code_verifier)
+
+                token = await client.fetch_token(
+                    config["token_url"],
+                    **token_params,
+                )
+
+                # SECURITY: Validate ID token signature and nonce for OpenID Connect
+                # This prevents token forgery and replay attacks (OIDC Core 3.1.3.7)
+                if provider == "google" and state_record.nonce:
+                    id_token = token.get("id_token")
+                    if id_token:
+                        await OAuthService._verify_google_id_token(
+                            id_token=str(id_token),
+                            expected_nonce=str(state_record.nonce),
+                            client_id=client_id,
+                        )
+            except AuthenticationError:
+                raise
+            except Exception as e:
+                logger.error("OAuth token exchange failed: %s", e)
+                raise AuthenticationError("Failed to exchange authorization code")
+
+            # Get user info from provider
+            try:
+                access_token = token.get("access_token")
+                if not access_token:
+                    raise AuthenticationError("No access token received")
+
+                user_info = await OAuthService._get_user_info(
+                    client, provider, config, access_token
+                )
+            except Exception as e:
+                logger.error("Failed to get user info: %s", e)
+                raise AuthenticationError(
+                    "Failed to get user information from provider"
+                )
+
+        # Process user info and create/link account
+        provider_user_id = str(user_info.get("id") or user_info.get("sub"))
+        # Email can be None if user didn't grant email permission
+        # SECURITY: Normalize email (lowercase, strip) to prevent case-based account duplication
+        email_raw = user_info.get("email")
+        provider_email: str | None = (
+            str(email_raw).lower().strip() if email_raw else None
+        )
+
+        if not provider_user_id:
+            raise AuthenticationError("Provider did not return user ID")
+
+        # Check if this OAuth account already exists
+        existing_oauth = await oauth_account.get_by_provider_id(
+            db, provider=provider, provider_user_id=provider_user_id
+        )
+
+        is_new_user = False
+
+        if existing_oauth:
+            # Existing OAuth account - login
+            user = existing_oauth.user
+            if not user.is_active:
+                raise AuthenticationError("User account is inactive")
+
+            # Update tokens if stored
+            if token.get("access_token"):
+                await oauth_account.update_tokens(
+                    db,
+                    account=existing_oauth,
+                    access_token=token.get("access_token"),
+                    refresh_token=token.get("refresh_token"),
+                    token_expires_at=datetime.now(UTC)
+                    + timedelta(seconds=token.get("expires_in", 3600)),
+                )
+
+            logger.info("OAuth login successful for %s via %s", user.email, provider)
+
+        elif state_record.user_id:
+            # Account linking flow (user is already logged in)
+            user = await user_repo.get(db, id=str(state_record.user_id))
+
+            if not user:
+                raise AuthenticationError("User not found for account linking")
+
+            # Check if user already has this provider linked
+            user_id = cast(UUID, user.id)
+            existing_provider = await oauth_account.get_user_account_by_provider(
+                db, user_id=user_id, provider=provider
+            )
+            if existing_provider:
+                raise AuthenticationError(
+                    f"You already have a {provider} account linked"
+                )
+
+            # Create OAuth account link
+            oauth_create = OAuthAccountCreate(
+                user_id=user_id,
+                provider=provider,
+                provider_user_id=provider_user_id,
+                provider_email=provider_email,
+                access_token=token.get("access_token"),
+                refresh_token=token.get("refresh_token"),
+                token_expires_at=datetime.now(UTC)
+                + timedelta(seconds=token.get("expires_in", 3600))
+                if token.get("expires_in")
+                else None,
+            )
+            await oauth_account.create_account(db, obj_in=oauth_create)
+
+            logger.info("OAuth account linked: %s -> %s", provider, user.email)
+
+        else:
+            # New OAuth login - check for existing user by email
+            user = None
+
+            if provider_email and settings.OAUTH_AUTO_LINK_BY_EMAIL:
+                user = await user_repo.get_by_email(db, email=provider_email)
+
+            if user:
+                # Auto-link to existing user
+                if not user.is_active:
+                    raise AuthenticationError("User account is inactive")
+
+                # Check if user already has this provider linked
+                user_id = cast(UUID, user.id)
+                existing_provider = await oauth_account.get_user_account_by_provider(
+                    db, user_id=user_id, provider=provider
+                )
+                if existing_provider:
+                    # This shouldn't happen if we got here, but safety check
+                    logger.warning(
+                        "OAuth account already linked (race condition?): %s -> %s",
+                        provider,
+                        user.email,
+                    )
+                else:
+                    # Create OAuth account link
+                    oauth_create = OAuthAccountCreate(
+                        user_id=user_id,
+                        provider=provider,
+                        provider_user_id=provider_user_id,
+                        provider_email=provider_email,
+                        access_token=token.get("access_token"),
+                        refresh_token=token.get("refresh_token"),
+                        token_expires_at=datetime.now(UTC)
+                        + timedelta(seconds=token.get("expires_in", 3600))
+                        if token.get("expires_in")
+                        else None,
+                    )
+                    await oauth_account.create_account(db, obj_in=oauth_create)
+
+                logger.info(
+                    "OAuth auto-linked by email: %s -> %s", provider, user.email
+                )
+
+            else:
+                # Create new user
+                if not provider_email:
+                    raise AuthenticationError(
+                        f"Email is required for registration. "
+                        f"Please grant email permission to {provider}."
+                    )
+
+                user = await OAuthService._create_oauth_user(
+                    db,
+                    email=provider_email,
+                    provider=provider,
+                    provider_user_id=provider_user_id,
+                    user_info=user_info,
+                    token=token,
+                )
+                is_new_user = True
+
+                logger.info("New user created via OAuth: %s (%s)", user.email, provider)
+
+        # Generate JWT tokens
+        claims = {
+            "is_superuser": user.is_superuser,
+            "email": user.email,
+            "first_name": user.first_name,
+        }
+
+        access_token_jwt = create_access_token(subject=str(user.id), claims=claims)
+        refresh_token_jwt = create_refresh_token(subject=str(user.id))
+
+        return OAuthCallbackResponse(
+            access_token=access_token_jwt,
+            refresh_token=refresh_token_jwt,
+            token_type="bearer",
+            expires_in=settings.ACCESS_TOKEN_EXPIRE_MINUTES * 60,
+            is_new_user=is_new_user,
+        )
+
+    @staticmethod
+    async def _get_user_info(
+        client: AsyncOAuth2Client,
+        provider: str,
+        config: OAuthProviderConfig,
+        access_token: str,
+    ) -> dict[str, object]:
+        """Get user info from OAuth provider."""
+        headers = {"Authorization": f"Bearer {access_token}"}
+
+        if provider == "github":
+            # GitHub returns JSON with Accept header
+            headers["Accept"] = "application/vnd.github+json"
+
+        resp = await client.get(config["userinfo_url"], headers=headers)
+        resp.raise_for_status()
+        user_info = resp.json()
+
+        # GitHub requires separate request for email
+        if provider == "github" and not user_info.get("email"):
+            email_resp = await client.get(
+                config["email_url"],  # pyright: ignore[reportTypedDictNotRequiredAccess]
+                headers=headers,
+            )
+            email_resp.raise_for_status()
+            emails = email_resp.json()
+
+            # Find primary verified email
+            for email_data in emails:
+                if email_data.get("primary") and email_data.get("verified"):
+                    user_info["email"] = email_data["email"]
+                    break
+
+        return user_info
+
+    # Google's OIDC configuration endpoints
+    GOOGLE_JWKS_URL = "https://www.googleapis.com/oauth2/v3/certs"
+    GOOGLE_ISSUERS = ("https://accounts.google.com", "accounts.google.com")
+
+    @staticmethod
+    async def _verify_google_id_token(
+        id_token: str,
+        expected_nonce: str,
+        client_id: str,
+    ) -> dict[str, object]:
+        """
+        Verify Google ID token signature and claims.
+
+        SECURITY: This properly verifies the ID token by:
+        1. Fetching Google's public keys (JWKS)
+        2. Verifying the JWT signature against the public key
+        3. Validating issuer, audience, expiry, and nonce claims
+
+        Args:
+            id_token: The ID token JWT string
+            expected_nonce: The nonce we sent in the authorization request
+            client_id: Our OAuth client ID (expected audience)
+
+        Returns:
+            Decoded ID token payload
+
+        Raises:
+            AuthenticationError: If verification fails
+        """
+        import httpx
+        import jwt as pyjwt
+        from jwt.algorithms import RSAAlgorithm
+        from jwt.exceptions import InvalidTokenError
+
+        try:
+            # Fetch Google's public keys (JWKS)
+            # In production, consider caching this with TTL matching Cache-Control header
+            async with httpx.AsyncClient() as client:
+                jwks_response = await client.get(
+                    OAuthService.GOOGLE_JWKS_URL,
+                    timeout=10.0,
+                )
+                jwks_response.raise_for_status()
+                jwks = jwks_response.json()
+
+            # Get the key ID from the token header
+            unverified_header = pyjwt.get_unverified_header(id_token)
+            kid = unverified_header.get("kid")
+            if not kid:
+                raise AuthenticationError("ID token missing key ID (kid)")
+
+            # Find the matching public key
+            jwk_data = None
+            for key in jwks.get("keys", []):
+                if key.get("kid") == kid:
+                    jwk_data = key
+                    break
+
+            if not jwk_data:
+                raise AuthenticationError("ID token signed with unknown key")
+
+            # Convert JWK to a public key object for PyJWT
+            public_key = RSAAlgorithm.from_jwk(jwk_data)
+
+            # Verify the token signature and decode claims
+            # PyJWT will verify signature against the RSA public key
+            payload = pyjwt.decode(
+                id_token,
+                public_key,
+                algorithms=["RS256"],  # Google uses RS256
+                audience=client_id,
+                issuer=OAuthService.GOOGLE_ISSUERS,
+                options={
+                    "verify_signature": True,
+                    "verify_aud": True,
+                    "verify_iss": True,
+                    "verify_exp": True,
+                    "verify_iat": True,
+                },
+            )
+
+            # Verify nonce (OIDC replay attack protection)
+            token_nonce = payload.get("nonce")
+            if token_nonce != expected_nonce:
+                logger.warning(
+                    "OAuth ID token nonce mismatch: expected %s, got %s",
+                    expected_nonce,
+                    token_nonce,
+                )
+                raise AuthenticationError("Invalid ID token nonce")
+
+            logger.debug("Google ID token verified successfully")
+            return payload
+
+        except InvalidTokenError as e:
+            logger.warning("Google ID token verification failed: %s", e)
+            raise AuthenticationError("Invalid ID token signature")
+        except httpx.HTTPError as e:
+            logger.error("Failed to fetch Google JWKS: %s", e)
+            # If we can't verify the ID token, fail closed for security
+            raise AuthenticationError("Failed to verify ID token")
+        except Exception as e:
+            logger.error("Unexpected error verifying Google ID token: %s", e)
+            raise AuthenticationError("ID token verification error")
+
+    @staticmethod
+    async def _create_oauth_user(
+        db: AsyncSession,
+        *,
+        email: str,
+        provider: str,
+        provider_user_id: str,
+        user_info: dict,
+        token: dict,
+    ) -> User:
+        """Create a new user from OAuth provider data."""
+        # Extract name from user_info
+        first_name = "User"
+        last_name = None
+
+        if provider == "google":
+            first_name = user_info.get("given_name") or user_info.get("name", "User")
+            last_name = user_info.get("family_name")
+        elif provider == "github":
+            # GitHub has full name, try to split
+            name = user_info.get("name") or user_info.get("login", "User")
+            parts = name.split(" ", 1)
+            first_name = parts[0]
+            last_name = parts[1] if len(parts) > 1 else None
+
+        # Create user (no password for OAuth-only users)
+        user = User(
+            email=email,
+            password_hash=None,  # OAuth-only user
+            first_name=first_name,
+            last_name=last_name,
+            is_active=True,
+            is_superuser=False,
+        )
+        db.add(user)
+        await db.flush()  # Get user.id
+
+        # Create OAuth account link
+        user_id = cast(UUID, user.id)
+        oauth_create = OAuthAccountCreate(
+            user_id=user_id,
+            provider=provider,
+            provider_user_id=provider_user_id,
+            provider_email=email,
+            access_token=token.get("access_token"),
+            refresh_token=token.get("refresh_token"),
+            token_expires_at=datetime.now(UTC)
+            + timedelta(seconds=token.get("expires_in", 3600))
+            if token.get("expires_in")
+            else None,
+        )
+        await oauth_account.create_account(db, obj_in=oauth_create)
+
+        await db.refresh(user)
+
+        return user
+
+    @staticmethod
+    async def unlink_provider(
+        db: AsyncSession,
+        *,
+        user: User,
+        provider: str,
+    ) -> bool:
+        """
+        Unlink an OAuth provider from a user account.
+
+        Args:
+            db: Database session
+            user: User to unlink from
+            provider: Provider to unlink
+
+        Returns:
+            True if unlinked successfully
+
+        Raises:
+            AuthenticationError: If unlinking would leave user without login method
+        """
+        # Check if user can safely remove this OAuth account
+        # Note: We query directly instead of using user.can_remove_oauth property
+        # because the property uses lazy loading which doesn't work in async context
+        user_id = cast(UUID, user.id)
+        has_password = user.password_hash is not None
+        oauth_accounts = await oauth_account.get_user_accounts(db, user_id=user_id)
+        can_remove = has_password or len(oauth_accounts) > 1
+
+        if not can_remove:
+            raise AuthenticationError(
+                "Cannot unlink OAuth account. You must have either a password set "
+                "or at least one other OAuth provider linked."
+            )
+
+        deleted = await oauth_account.delete_account(
+            db, user_id=user_id, provider=provider
+        )
+
+        if not deleted:
+            raise AuthenticationError(f"No {provider} account found to unlink")
+
+        logger.info("OAuth provider unlinked: %s from %s", provider, user.email)
+        return True
+
+    @staticmethod
+    async def get_user_accounts(db: AsyncSession, *, user_id: UUID) -> list:
+        """Get all OAuth accounts linked to a user."""
+        return await oauth_account.get_user_accounts(db, user_id=user_id)
+
+    @staticmethod
+    async def get_user_account_by_provider(
+        db: AsyncSession, *, user_id: UUID, provider: str
+    ):
+        """Get a specific OAuth account for a user and provider."""
+        return await oauth_account.get_user_account_by_provider(
+            db, user_id=user_id, provider=provider
+        )
+
+    @staticmethod
+    async def cleanup_expired_states(db: AsyncSession) -> int:
+        """
+        Clean up expired OAuth states.
+
+        Should be called periodically (e.g., by a background task).
+
+        Args:
+            db: Database session
+
+        Returns:
+            Number of states cleaned up
+        """
+        return await oauth_state.cleanup_expired(db)

backend/app/services/organization_service.py

@@ -0,0 +1,155 @@
+# app/services/organization_service.py
+"""Service layer for organization operations — delegates to OrganizationRepository."""
+
+import logging
+from typing import Any
+from uuid import UUID
+
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.exceptions import NotFoundError
+from app.models.organization import Organization
+from app.models.user_organization import OrganizationRole, UserOrganization
+from app.repositories.organization import OrganizationRepository, organization_repo
+from app.schemas.organizations import OrganizationCreate, OrganizationUpdate
+
+logger = logging.getLogger(__name__)
+
+
+class OrganizationService:
+    """Service for organization management operations."""
+
+    def __init__(
+        self, organization_repository: OrganizationRepository | None = None
+    ) -> None:
+        self._repo = organization_repository or organization_repo
+
+    async def get_organization(self, db: AsyncSession, org_id: str) -> Organization:
+        """Get organization by ID, raising NotFoundError if not found."""
+        org = await self._repo.get(db, id=org_id)
+        if not org:
+            raise NotFoundError(f"Organization {org_id} not found")
+        return org
+
+    async def create_organization(
+        self, db: AsyncSession, *, obj_in: OrganizationCreate
+    ) -> Organization:
+        """Create a new organization."""
+        return await self._repo.create(db, obj_in=obj_in)
+
+    async def update_organization(
+        self,
+        db: AsyncSession,
+        *,
+        org: Organization,
+        obj_in: OrganizationUpdate | dict[str, Any],
+    ) -> Organization:
+        """Update an existing organization."""
+        return await self._repo.update(db, db_obj=org, obj_in=obj_in)
+
+    async def remove_organization(self, db: AsyncSession, org_id: str) -> None:
+        """Permanently delete an organization by ID."""
+        await self._repo.remove(db, id=org_id)
+
+    async def get_member_count(self, db: AsyncSession, *, organization_id: UUID) -> int:
+        """Get number of active members in an organization."""
+        return await self._repo.get_member_count(db, organization_id=organization_id)
+
+    async def get_multi_with_member_counts(
+        self,
+        db: AsyncSession,
+        *,
+        skip: int = 0,
+        limit: int = 100,
+        is_active: bool | None = None,
+        search: str | None = None,
+    ) -> tuple[list[dict[str, Any]], int]:
+        """List organizations with member counts and pagination."""
+        return await self._repo.get_multi_with_member_counts(
+            db, skip=skip, limit=limit, is_active=is_active, search=search
+        )
+
+    async def get_user_organizations_with_details(
+        self,
+        db: AsyncSession,
+        *,
+        user_id: UUID,
+        is_active: bool | None = None,
+    ) -> list[dict[str, Any]]:
+        """Get all organizations a user belongs to, with membership details."""
+        return await self._repo.get_user_organizations_with_details(
+            db, user_id=user_id, is_active=is_active
+        )
+
+    async def get_organization_members(
+        self,
+        db: AsyncSession,
+        *,
+        organization_id: UUID,
+        skip: int = 0,
+        limit: int = 100,
+        is_active: bool | None = True,
+    ) -> tuple[list[dict[str, Any]], int]:
+        """Get members of an organization with pagination."""
+        return await self._repo.get_organization_members(
+            db,
+            organization_id=organization_id,
+            skip=skip,
+            limit=limit,
+            is_active=is_active,
+        )
+
+    async def add_member(
+        self,
+        db: AsyncSession,
+        *,
+        organization_id: UUID,
+        user_id: UUID,
+        role: OrganizationRole = OrganizationRole.MEMBER,
+    ) -> UserOrganization:
+        """Add a user to an organization."""
+        return await self._repo.add_user(
+            db, organization_id=organization_id, user_id=user_id, role=role
+        )
+
+    async def remove_member(
+        self,
+        db: AsyncSession,
+        *,
+        organization_id: UUID,
+        user_id: UUID,
+    ) -> bool:
+        """Remove a user from an organization. Returns True if found and removed."""
+        return await self._repo.remove_user(
+            db, organization_id=organization_id, user_id=user_id
+        )
+
+    async def get_user_role_in_org(
+        self, db: AsyncSession, *, user_id: UUID, organization_id: UUID
+    ) -> OrganizationRole | None:
+        """Get the role of a user in an organization."""
+        return await self._repo.get_user_role_in_org(
+            db, user_id=user_id, organization_id=organization_id
+        )
+
+    async def get_org_distribution(
+        self, db: AsyncSession, *, limit: int = 6
+    ) -> list[dict[str, Any]]:
+        """Return top organizations by member count for admin dashboard."""
+        from sqlalchemy import func, select
+
+        result = await db.execute(
+            select(
+                Organization.name,
+                func.count(UserOrganization.user_id).label("count"),
+            )
+            .join(UserOrganization, Organization.id == UserOrganization.organization_id)
+            .group_by(Organization.name)
+            .order_by(func.count(UserOrganization.user_id).desc())
+            .limit(limit)
+        )
+        return [{"name": row.name, "value": row.count} for row in result.all()]
+
+
+# Default singleton
+organization_service = OrganizationService()

backend/app/services/session_cleanup.py

@@ -3,11 +3,12 @@ Background job for cleaning up expired sessions.
 
 This service runs periodically to remove old session records from the database.
 """
+
 import logging
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 
 from app.core.database import SessionLocal
-from app.crud.session import session as session_crud
+from app.repositories.session import session_repo as session_repo
 
 logger = logging.getLogger(__name__)
 
@@ -31,15 +32,15 @@ async def cleanup_expired_sessions(keep_days: int = 30) -> int:
 
     async with SessionLocal() as db:
         try:
-            # Use CRUD method to cleanup
-            count = await session_crud.cleanup_expired(db, keep_days=keep_days)
+            # Use repository method to cleanup
+            count = await session_repo.cleanup_expired(db, keep_days=keep_days)
 
-            logger.info(f"Session cleanup complete: {count} sessions deleted")
+            logger.info("Session cleanup complete: %s sessions deleted", count)
 
             return count
 
         except Exception as e:
-            logger.error(f"Error during session cleanup: {str(e)}", exc_info=True)
+            logger.exception("Error during session cleanup: %s", e)
             return 0
 
 
@@ -52,20 +53,21 @@ async def get_session_statistics() -> dict:
     """
     async with SessionLocal() as db:
         try:
+            from sqlalchemy import func, select
+
             from app.models.user_session import UserSession
-            from sqlalchemy import select, func
 
             total_result = await db.execute(select(func.count(UserSession.id)))
             total_sessions = total_result.scalar_one()
 
             active_result = await db.execute(
-                select(func.count(UserSession.id)).where(UserSession.is_active == True)
+                select(func.count(UserSession.id)).where(UserSession.is_active)
             )
             active_sessions = active_result.scalar_one()
 
             expired_result = await db.execute(
                 select(func.count(UserSession.id)).where(
-                    UserSession.expires_at < datetime.now(timezone.utc)
+                    UserSession.expires_at < datetime.now(UTC)
                 )
             )
             expired_sessions = expired_result.scalar_one()
@@ -77,10 +79,10 @@ async def get_session_statistics() -> dict:
                 "expired": expired_sessions,
             }
 
-            logger.info(f"Session statistics: {stats}")
+            logger.info("Session statistics: %s", stats)
 
             return stats
 
         except Exception as e:
-            logger.error(f"Error getting session statistics: {str(e)}", exc_info=True)
+            logger.exception("Error getting session statistics: %s", e)
             return {}

backend/app/services/session_service.py

@@ -0,0 +1,97 @@
+# app/services/session_service.py
+"""Service layer for session operations — delegates to SessionRepository."""
+
+import logging
+from datetime import datetime
+
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.models.user_session import UserSession
+from app.repositories.session import SessionRepository, session_repo
+from app.schemas.sessions import SessionCreate
+
+logger = logging.getLogger(__name__)
+
+
+class SessionService:
+    """Service for user session management operations."""
+
+    def __init__(self, session_repository: SessionRepository | None = None) -> None:
+        self._repo = session_repository or session_repo
+
+    async def create_session(
+        self, db: AsyncSession, *, obj_in: SessionCreate
+    ) -> UserSession:
+        """Create a new session record."""
+        return await self._repo.create_session(db, obj_in=obj_in)
+
+    async def get_session(
+        self, db: AsyncSession, session_id: str
+    ) -> UserSession | None:
+        """Get session by ID."""
+        return await self._repo.get(db, id=session_id)
+
+    async def get_user_sessions(
+        self, db: AsyncSession, *, user_id: str, active_only: bool = True
+    ) -> list[UserSession]:
+        """Get all sessions for a user."""
+        return await self._repo.get_user_sessions(
+            db, user_id=user_id, active_only=active_only
+        )
+
+    async def get_active_by_jti(
+        self, db: AsyncSession, *, jti: str
+    ) -> UserSession | None:
+        """Get active session by refresh token JTI."""
+        return await self._repo.get_active_by_jti(db, jti=jti)
+
+    async def get_by_jti(self, db: AsyncSession, *, jti: str) -> UserSession | None:
+        """Get session by refresh token JTI (active or inactive)."""
+        return await self._repo.get_by_jti(db, jti=jti)
+
+    async def deactivate(
+        self, db: AsyncSession, *, session_id: str
+    ) -> UserSession | None:
+        """Deactivate a session (logout from device)."""
+        return await self._repo.deactivate(db, session_id=session_id)
+
+    async def deactivate_all_user_sessions(
+        self, db: AsyncSession, *, user_id: str
+    ) -> int:
+        """Deactivate all sessions for a user. Returns count deactivated."""
+        return await self._repo.deactivate_all_user_sessions(db, user_id=user_id)
+
+    async def update_refresh_token(
+        self,
+        db: AsyncSession,
+        *,
+        session: UserSession,
+        new_jti: str,
+        new_expires_at: datetime,
+    ) -> UserSession:
+        """Update session with a rotated refresh token."""
+        return await self._repo.update_refresh_token(
+            db, session=session, new_jti=new_jti, new_expires_at=new_expires_at
+        )
+
+    async def cleanup_expired_for_user(self, db: AsyncSession, *, user_id: str) -> int:
+        """Remove expired sessions for a user. Returns count removed."""
+        return await self._repo.cleanup_expired_for_user(db, user_id=user_id)
+
+    async def get_all_sessions(
+        self,
+        db: AsyncSession,
+        *,
+        skip: int = 0,
+        limit: int = 100,
+        active_only: bool = True,
+        with_user: bool = True,
+    ) -> tuple[list[UserSession], int]:
+        """Get all sessions with pagination (admin only)."""
+        return await self._repo.get_all_sessions(
+            db, skip=skip, limit=limit, active_only=active_only, with_user=with_user
+        )
+
+
+# Default singleton
+session_service = SessionService()

backend/app/services/user_service.py

@@ -0,0 +1,120 @@
+# app/services/user_service.py
+"""Service layer for user operations — delegates to UserRepository."""
+
+import logging
+from typing import Any
+from uuid import UUID
+
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.exceptions import NotFoundError
+from app.models.user import User
+from app.repositories.user import UserRepository, user_repo
+from app.schemas.users import UserCreate, UserUpdate
+
+logger = logging.getLogger(__name__)
+
+
+class UserService:
+    """Service for user management operations."""
+
+    def __init__(self, user_repository: UserRepository | None = None) -> None:
+        self._repo = user_repository or user_repo
+
+    async def get_user(self, db: AsyncSession, user_id: str) -> User:
+        """Get user by ID, raising NotFoundError if not found."""
+        user = await self._repo.get(db, id=user_id)
+        if not user:
+            raise NotFoundError(f"User {user_id} not found")
+        return user
+
+    async def get_by_email(self, db: AsyncSession, email: str) -> User | None:
+        """Get user by email address."""
+        return await self._repo.get_by_email(db, email=email)
+
+    async def create_user(self, db: AsyncSession, user_data: UserCreate) -> User:
+        """Create a new user."""
+        return await self._repo.create(db, obj_in=user_data)
+
+    async def update_user(
+        self, db: AsyncSession, *, user: User, obj_in: UserUpdate | dict[str, Any]
+    ) -> User:
+        """Update an existing user."""
+        return await self._repo.update(db, db_obj=user, obj_in=obj_in)
+
+    async def soft_delete_user(self, db: AsyncSession, user_id: str) -> None:
+        """Soft-delete a user by ID."""
+        await self._repo.soft_delete(db, id=user_id)
+
+    async def list_users(
+        self,
+        db: AsyncSession,
+        *,
+        skip: int = 0,
+        limit: int = 100,
+        sort_by: str | None = None,
+        sort_order: str = "asc",
+        filters: dict[str, Any] | None = None,
+        search: str | None = None,
+    ) -> tuple[list[User], int]:
+        """List users with pagination, sorting, filtering, and search."""
+        return await self._repo.get_multi_with_total(
+            db,
+            skip=skip,
+            limit=limit,
+            sort_by=sort_by,
+            sort_order=sort_order,
+            filters=filters,
+            search=search,
+        )
+
+    async def bulk_update_status(
+        self, db: AsyncSession, *, user_ids: list[UUID], is_active: bool
+    ) -> int:
+        """Bulk update active status for multiple users. Returns count updated."""
+        return await self._repo.bulk_update_status(
+            db, user_ids=user_ids, is_active=is_active
+        )
+
+    async def bulk_soft_delete(
+        self,
+        db: AsyncSession,
+        *,
+        user_ids: list[UUID],
+        exclude_user_id: UUID | None = None,
+    ) -> int:
+        """Bulk soft-delete multiple users. Returns count deleted."""
+        return await self._repo.bulk_soft_delete(
+            db, user_ids=user_ids, exclude_user_id=exclude_user_id
+        )
+
+    async def get_stats(self, db: AsyncSession) -> dict[str, Any]:
+        """Return user stats needed for the admin dashboard."""
+        from sqlalchemy import func, select
+
+        total_users = (
+            await db.execute(select(func.count()).select_from(User))
+        ).scalar() or 0
+        active_count = (
+            await db.execute(
+                select(func.count()).select_from(User).where(User.is_active)
+            )
+        ).scalar() or 0
+        inactive_count = (
+            await db.execute(
+                select(func.count()).select_from(User).where(User.is_active.is_(False))
+            )
+        ).scalar() or 0
+        all_users = list(
+            (await db.execute(select(User).order_by(User.created_at))).scalars().all()
+        )
+        return {
+            "total_users": total_users,
+            "active_count": active_count,
+            "inactive_count": inactive_count,
+            "all_users": all_users,
+        }
+
+
+# Default singleton
+user_service = UserService()

backend/app/utils/auth_test_utils.py

@@ -2,7 +2,8 @@
 Authentication utilities for testing.
 This module provides tools to bypass FastAPI's authentication in tests.
 """
-from typing import Callable, Dict, Optional
+
+from collections.abc import Callable
 
 from fastapi import FastAPI
 from fastapi.security import OAuth2PasswordBearer
@@ -13,9 +14,9 @@ from app.models.user import User
 
 
 def create_test_auth_client(
-        app: FastAPI,
-        test_user: User,
-        extra_overrides: Optional[Dict[Callable, Callable]] = None
+    app: FastAPI,
+    test_user: User,
+    extra_overrides: dict[Callable, Callable] | None = None,
 ) -> TestClient:
     """
     Create a test client with authentication pre-configured.
@@ -47,10 +48,7 @@ def create_test_auth_client(
     return TestClient(app)
 
 
-def create_test_optional_auth_client(
-        app: FastAPI,
-        test_user: User
-) -> TestClient:
+def create_test_optional_auth_client(app: FastAPI, test_user: User) -> TestClient:
     """
     Create a test client with optional authentication pre-configured.
 
@@ -70,10 +68,7 @@ def create_test_optional_auth_client(
     return TestClient(app)
 
 
-def create_test_superuser_client(
-        app: FastAPI,
-        test_user: User
-) -> TestClient:
+def create_test_superuser_client(app: FastAPI, test_user: User) -> TestClient:
     """
     Create a test client with superuser authentication pre-configured.
 
@@ -120,7 +115,7 @@ def cleanup_test_client_auth(app: FastAPI) -> None:
     auth_deps = [
         get_current_user,
         get_optional_current_user,
-        OAuth2PasswordBearer(tokenUrl="/api/v1/auth/login")
+        OAuth2PasswordBearer(tokenUrl="/api/v1/auth/login"),
     ]
 
     # Remove overrides

backend/app/utils/device.py

@@ -1,8 +1,8 @@
 """
 Utility functions for extracting and parsing device information from HTTP requests.
 """
+
 import re
-from typing import Optional
 
 from fastapi import Request
 
@@ -19,11 +19,11 @@ def extract_device_info(request: Request) -> DeviceInfo:
     Returns:
         DeviceInfo object with parsed device information
     """
-    user_agent = request.headers.get('user-agent', '')
+    user_agent = request.headers.get("user-agent", "")
 
     device_info = DeviceInfo(
         device_name=parse_device_name(user_agent),
-        device_id=request.headers.get('x-device-id'),  # Client must send this header
+        device_id=request.headers.get("x-device-id"),  # Client must send this header
         ip_address=get_client_ip(request),
         user_agent=user_agent[:500] if user_agent else None,  # Truncate to max length
         location_city=None,  # Can be populated via IP geolocation service
@@ -33,7 +33,7 @@ def extract_device_info(request: Request) -> DeviceInfo:
     return device_info
 
 
-def parse_device_name(user_agent: str) -> Optional[str]:
+def parse_device_name(user_agent: str) -> str | None:
     """
     Parse user agent string to extract a friendly device name.
 
@@ -54,48 +54,48 @@ def parse_device_name(user_agent: str) -> Optional[str]:
     user_agent_lower = user_agent.lower()
 
     # Mobile devices (check first, as they can contain desktop patterns too)
-    if 'iphone' in user_agent_lower:
+    if "iphone" in user_agent_lower:
         return "iPhone"
-    elif 'ipad' in user_agent_lower:
+    elif "ipad" in user_agent_lower:
         return "iPad"
-    elif 'android' in user_agent_lower:
+    elif "android" in user_agent_lower:
         # Try to extract device model
-        android_match = re.search(r'android.*;\s*([^)]+)\s*build', user_agent_lower)
+        android_match = re.search(r"android.*;\s*([^)]+)\s*build", user_agent_lower)
         if android_match:
             device_model = android_match.group(1).strip()
             return f"Android ({device_model.title()})"
         return "Android device"
-    elif 'windows phone' in user_agent_lower:
+    elif "windows phone" in user_agent_lower:
         return "Windows Phone"
 
     # Tablets (check before desktop, as some tablets contain "android")
-    elif 'tablet' in user_agent_lower:
+    elif "tablet" in user_agent_lower:
         return "Tablet"
 
     # Smart TVs (check before desktop OS patterns)
-    elif any(tv in user_agent_lower for tv in ['smart-tv', 'smarttv']):
+    elif any(tv in user_agent_lower for tv in ["smart-tv", "smarttv"]):
         return "Smart TV"
 
     # Game consoles (check before desktop OS patterns, as Xbox contains "Windows")
-    elif 'playstation' in user_agent_lower:
+    elif "playstation" in user_agent_lower:
         return "PlayStation"
-    elif 'xbox' in user_agent_lower:
+    elif "xbox" in user_agent_lower:
         return "Xbox"
-    elif 'nintendo' in user_agent_lower:
+    elif "nintendo" in user_agent_lower:
         return "Nintendo"
 
     # Desktop operating systems
-    elif 'macintosh' in user_agent_lower or 'mac os x' in user_agent_lower:
+    elif "macintosh" in user_agent_lower or "mac os x" in user_agent_lower:
         # Try to extract browser
         browser = extract_browser(user_agent)
         return f"{browser} on Mac" if browser else "Mac"
-    elif 'windows' in user_agent_lower:
+    elif "windows" in user_agent_lower:
         browser = extract_browser(user_agent)
         return f"{browser} on Windows" if browser else "Windows PC"
-    elif 'linux' in user_agent_lower and 'android' not in user_agent_lower:
+    elif "linux" in user_agent_lower and "android" not in user_agent_lower:
         browser = extract_browser(user_agent)
         return f"{browser} on Linux" if browser else "Linux"
-    elif 'cros' in user_agent_lower:
+    elif "cros" in user_agent_lower:
         return "Chromebook"
 
     # Fallback: just return browser name if detected
@@ -106,7 +106,7 @@ def parse_device_name(user_agent: str) -> Optional[str]:
     return "Unknown device"
 
 
-def extract_browser(user_agent: str) -> Optional[str]:
+def extract_browser(user_agent: str) -> str | None:
     """
     Extract browser name from user agent string.
 
@@ -126,26 +126,26 @@ def extract_browser(user_agent: str) -> Optional[str]:
     user_agent_lower = user_agent.lower()
 
     # Check specific browsers (order matters - check Edge before Chrome!)
-    if 'edg/' in user_agent_lower or 'edge/' in user_agent_lower:
+    if "edg/" in user_agent_lower or "edge/" in user_agent_lower:
         return "Edge"
-    elif 'opr/' in user_agent_lower or 'opera' in user_agent_lower:
+    elif "opr/" in user_agent_lower or "opera" in user_agent_lower:
         return "Opera"
-    elif 'chrome/' in user_agent_lower:
+    elif "chrome/" in user_agent_lower:
         return "Chrome"
-    elif 'safari/' in user_agent_lower:
+    elif "safari/" in user_agent_lower:
         # Make sure it's actually Safari, not Chrome (which also contains "Safari")
-        if 'chrome' not in user_agent_lower:
+        if "chrome" not in user_agent_lower:
             return "Safari"
         return None
-    elif 'firefox/' in user_agent_lower:
+    elif "firefox/" in user_agent_lower:
         return "Firefox"
-    elif 'msie' in user_agent_lower or 'trident/' in user_agent_lower:
+    elif "msie" in user_agent_lower or "trident/" in user_agent_lower:
         return "Internet Explorer"
 
     return None
 
 
-def get_client_ip(request: Request) -> Optional[str]:
+def get_client_ip(request: Request) -> str | None:
     """
     Extract client IP address from request, considering proxy headers.
 
@@ -163,14 +163,14 @@ def get_client_ip(request: Request) -> Optional[str]:
         - request.client.host is fallback for direct connections
     """
     # Check X-Forwarded-For (common in proxied environments)
-    x_forwarded_for = request.headers.get('x-forwarded-for')
+    x_forwarded_for = request.headers.get("x-forwarded-for")
     if x_forwarded_for:
         # Get the first IP (original client)
-        client_ip = x_forwarded_for.split(',')[0].strip()
+        client_ip = x_forwarded_for.split(",")[0].strip()
         return client_ip
 
     # Check X-Real-IP (used by some proxies like nginx)
-    x_real_ip = request.headers.get('x-real-ip')
+    x_real_ip = request.headers.get("x-real-ip")
     if x_real_ip:
         return x_real_ip.strip()
 
@@ -195,9 +195,17 @@ def is_mobile_device(user_agent: str) -> bool:
         return False
 
     mobile_patterns = [
-        'mobile', 'android', 'iphone', 'ipad', 'ipod',
-        'blackberry', 'windows phone', 'webos', 'opera mini',
-        'iemobile', 'mobile safari'
+        "mobile",
+        "android",
+        "iphone",
+        "ipad",
+        "ipod",
+        "blackberry",
+        "windows phone",
+        "webos",
+        "opera mini",
+        "iemobile",
+        "mobile safari",
     ]
 
     user_agent_lower = user_agent.lower()
@@ -220,7 +228,7 @@ def get_device_type(user_agent: str) -> str:
     user_agent_lower = user_agent.lower()
 
     # Check for tablets first (they can contain "mobile" too)
-    if 'ipad' in user_agent_lower or 'tablet' in user_agent_lower:
+    if "ipad" in user_agent_lower or "tablet" in user_agent_lower:
         return "tablet"
 
     # Check for mobile
@@ -228,7 +236,7 @@ def get_device_type(user_agent: str) -> str:
         return "mobile"
 
     # Check for desktop OS patterns
-    if any(os in user_agent_lower for os in ['windows', 'macintosh', 'linux', 'cros']):
+    if any(os in user_agent_lower for os in ["windows", "macintosh", "linux", "cros"]):
         return "desktop"
 
     return "other"

backend/app/utils/security.py

@@ -5,18 +5,21 @@ This module provides utilities for creating and verifying signed tokens,
 useful for operations like file uploads, password resets, or any other
 time-limited, single-use operations.
 """
+
 import base64
 import hashlib
 import hmac
 import json
 import secrets
 import time
-from typing import Dict, Any, Optional
+from typing import Any
 
 from app.core.config import settings
 
 
-def create_upload_token(file_path: str, content_type: str, expires_in: int = 300) -> str:
+def create_upload_token(
+    file_path: str, content_type: str, expires_in: int = 300
+) -> str:
     """
     Create a signed token for secure file uploads.
 
@@ -40,34 +43,29 @@ def create_upload_token(file_path: str, content_type: str, expires_in: int = 300
         "path": file_path,
         "content_type": content_type,
         "exp": int(time.time()) + expires_in,
-        "nonce": secrets.token_hex(8)  # Add randomness to prevent token reuse
+        "nonce": secrets.token_hex(8),  # Add randomness to prevent token reuse
     }
 
     # Convert to JSON and encode
-    payload_bytes = json.dumps(payload).encode('utf-8')
+    payload_bytes = json.dumps(payload).encode("utf-8")
 
     # Create a signature using HMAC-SHA256 for security
     # This prevents length extension attacks that plain SHA-256 is vulnerable to
     signature = hmac.new(
-        settings.SECRET_KEY.encode('utf-8'),
-        payload_bytes,
-        hashlib.sha256
+        settings.SECRET_KEY.encode("utf-8"), payload_bytes, hashlib.sha256
     ).hexdigest()
 
     # Combine payload and signature
-    token_data = {
-        "payload": payload,
-        "signature": signature
-    }
+    token_data = {"payload": payload, "signature": signature}
 
     # Encode the final token
     token_json = json.dumps(token_data)
-    token = base64.urlsafe_b64encode(token_json.encode('utf-8')).decode('utf-8')
+    token = base64.urlsafe_b64encode(token_json.encode("utf-8")).decode("utf-8")
 
     return token
 
 
-def verify_upload_token(token: str) -> Optional[Dict[str, Any]]:
+def verify_upload_token(token: str) -> dict[str, Any] | None:
     """
     Verify an upload token and return the payload if valid.
 
@@ -88,7 +86,7 @@ def verify_upload_token(token: str) -> Optional[Dict[str, Any]]:
     """
     try:
         # Decode the token
-        token_json = base64.urlsafe_b64decode(token.encode('utf-8')).decode('utf-8')
+        token_json = base64.urlsafe_b64decode(token.encode("utf-8")).decode("utf-8")
         token_data = json.loads(token_json)
 
         # Extract payload and signature
@@ -96,11 +94,9 @@ def verify_upload_token(token: str) -> Optional[Dict[str, Any]]:
         signature = token_data["signature"]
 
         # Verify signature using HMAC and constant-time comparison
-        payload_bytes = json.dumps(payload).encode('utf-8')
+        payload_bytes = json.dumps(payload).encode("utf-8")
         expected_signature = hmac.new(
-            settings.SECRET_KEY.encode('utf-8'),
-            payload_bytes,
-            hashlib.sha256
+            settings.SECRET_KEY.encode("utf-8"), payload_bytes, hashlib.sha256
         ).hexdigest()
 
         if not hmac.compare_digest(signature, expected_signature):
@@ -136,34 +132,29 @@ def create_password_reset_token(email: str, expires_in: int = 3600) -> str:
         "email": email,
         "exp": int(time.time()) + expires_in,
         "nonce": secrets.token_hex(16),  # Extra randomness
-        "purpose": "password_reset"
+        "purpose": "password_reset",
     }
 
     # Convert to JSON and encode
-    payload_bytes = json.dumps(payload).encode('utf-8')
+    payload_bytes = json.dumps(payload).encode("utf-8")
 
     # Create a signature using HMAC-SHA256 for security
     # This prevents length extension attacks that plain SHA-256 is vulnerable to
     signature = hmac.new(
-        settings.SECRET_KEY.encode('utf-8'),
-        payload_bytes,
-        hashlib.sha256
+        settings.SECRET_KEY.encode("utf-8"), payload_bytes, hashlib.sha256
     ).hexdigest()
 
     # Combine payload and signature
-    token_data = {
-        "payload": payload,
-        "signature": signature
-    }
+    token_data = {"payload": payload, "signature": signature}
 
     # Encode the final token
     token_json = json.dumps(token_data)
-    token = base64.urlsafe_b64encode(token_json.encode('utf-8')).decode('utf-8')
+    token = base64.urlsafe_b64encode(token_json.encode("utf-8")).decode("utf-8")
 
     return token
 
 
-def verify_password_reset_token(token: str) -> Optional[str]:
+def verify_password_reset_token(token: str) -> str | None:
     """
     Verify a password reset token and return the email if valid.
 
@@ -182,7 +173,7 @@ def verify_password_reset_token(token: str) -> Optional[str]:
     """
     try:
         # Decode the token
-        token_json = base64.urlsafe_b64decode(token.encode('utf-8')).decode('utf-8')
+        token_json = base64.urlsafe_b64decode(token.encode("utf-8")).decode("utf-8")
         token_data = json.loads(token_json)
 
         # Extract payload and signature
@@ -194,11 +185,9 @@ def verify_password_reset_token(token: str) -> Optional[str]:
             return None
 
         # Verify signature using HMAC and constant-time comparison
-        payload_bytes = json.dumps(payload).encode('utf-8')
+        payload_bytes = json.dumps(payload).encode("utf-8")
         expected_signature = hmac.new(
-            settings.SECRET_KEY.encode('utf-8'),
-            payload_bytes,
-            hashlib.sha256
+            settings.SECRET_KEY.encode("utf-8"), payload_bytes, hashlib.sha256
         ).hexdigest()
 
         if not hmac.compare_digest(signature, expected_signature):
@@ -234,34 +223,29 @@ def create_email_verification_token(email: str, expires_in: int = 86400) -> str:
         "email": email,
         "exp": int(time.time()) + expires_in,
         "nonce": secrets.token_hex(16),
-        "purpose": "email_verification"
+        "purpose": "email_verification",
     }
 
     # Convert to JSON and encode
-    payload_bytes = json.dumps(payload).encode('utf-8')
+    payload_bytes = json.dumps(payload).encode("utf-8")
 
     # Create a signature using HMAC-SHA256 for security
     # This prevents length extension attacks that plain SHA-256 is vulnerable to
     signature = hmac.new(
-        settings.SECRET_KEY.encode('utf-8'),
-        payload_bytes,
-        hashlib.sha256
+        settings.SECRET_KEY.encode("utf-8"), payload_bytes, hashlib.sha256
     ).hexdigest()
 
     # Combine payload and signature
-    token_data = {
-        "payload": payload,
-        "signature": signature
-    }
+    token_data = {"payload": payload, "signature": signature}
 
     # Encode the final token
     token_json = json.dumps(token_data)
-    token = base64.urlsafe_b64encode(token_json.encode('utf-8')).decode('utf-8')
+    token = base64.urlsafe_b64encode(token_json.encode("utf-8")).decode("utf-8")
 
     return token
 
 
-def verify_email_verification_token(token: str) -> Optional[str]:
+def verify_email_verification_token(token: str) -> str | None:
     """
     Verify an email verification token and return the email if valid.
 
@@ -280,7 +264,7 @@ def verify_email_verification_token(token: str) -> Optional[str]:
     """
     try:
         # Decode the token
-        token_json = base64.urlsafe_b64decode(token.encode('utf-8')).decode('utf-8')
+        token_json = base64.urlsafe_b64decode(token.encode("utf-8")).decode("utf-8")
         token_data = json.loads(token_json)
 
         # Extract payload and signature
@@ -292,11 +276,9 @@ def verify_email_verification_token(token: str) -> Optional[str]:
             return None
 
         # Verify signature using HMAC and constant-time comparison
-        payload_bytes = json.dumps(payload).encode('utf-8')
+        payload_bytes = json.dumps(payload).encode("utf-8")
         expected_signature = hmac.new(
-            settings.SECRET_KEY.encode('utf-8'),
-            payload_bytes,
-            hashlib.sha256
+            settings.SECRET_KEY.encode("utf-8"), payload_bytes, hashlib.sha256
         ).hexdigest()
 
         if not hmac.compare_digest(signature, expected_signature):

backend/app/utils/test_utils.py

@@ -9,17 +9,19 @@ from app.core.database import Base
 
 logger = logging.getLogger(__name__)
 
+
 def get_test_engine():
     """Create an SQLite in-memory engine specifically for testing"""
     test_engine = create_engine(
         "sqlite:///:memory:",
         connect_args={"check_same_thread": False},
         poolclass=StaticPool,  # Use static pool for in-memory testing
-        echo=False
+        echo=False,
     )
 
     return test_engine
 
+
 def setup_test_db():
     """Create a test database and session factory"""
     # Create a new engine for this test run
@@ -30,14 +32,12 @@ def setup_test_db():
 
     # Create session factory
     TestingSessionLocal = sessionmaker(
-        autocommit=False,
-        autoflush=False,
-        bind=test_engine,
-        expire_on_commit=False
+        autocommit=False, autoflush=False, bind=test_engine, expire_on_commit=False
     )
 
     return test_engine, TestingSessionLocal
 
+
 def teardown_test_db(engine):
     """Clean up after tests"""
     # Drop all tables
@@ -46,13 +46,14 @@ def teardown_test_db(engine):
     # Dispose of engine
     engine.dispose()
 
+
 async def get_async_test_engine():
     """Create an async SQLite in-memory engine specifically for testing"""
     test_engine = create_async_engine(
         "sqlite+aiosqlite:///:memory:",
         connect_args={"check_same_thread": False},
         poolclass=StaticPool,  # Use static pool for in-memory testing
-        echo=False
+        echo=False,
     )
     return test_engine
 
@@ -64,12 +65,12 @@ async def setup_async_test_db():
     async with test_engine.begin() as conn:
         await conn.run_sync(Base.metadata.create_all)
 
-    AsyncTestingSessionLocal = sessionmaker(
+    AsyncTestingSessionLocal = sessionmaker(  # pyright: ignore[reportCallIssue]
         autocommit=False,
         autoflush=False,
-        bind=test_engine,
+        bind=test_engine,  # pyright: ignore[reportArgumentType]
         expire_on_commit=False,
-        class_=AsyncSession
+        class_=AsyncSession,
     )
 
     return test_engine, AsyncTestingSessionLocal

backend/docs/ARCHITECTURE.md

@@ -79,12 +79,13 @@ This FastAPI backend application follows a **clean layered architecture** patter
 
 ### Authentication & Security
 
-- **python-jose**: JWT token generation and validation
-  - Cryptographic signing
+- **PyJWT**: JWT token generation and validation
+  - Cryptographic signing (HS256, RS256)
   - Token expiration handling
   - Claims validation
+  - JWK support for Google ID token verification
 
-- **passlib + bcrypt**: Password hashing
+- **bcrypt**: Password hashing
   - Industry-standard bcrypt algorithm
   - Configurable cost factor
   - Salt generation
@@ -117,7 +118,8 @@ backend/
 │   ├── api/                        # API layer
 │   │   ├── dependencies/           # Dependency injection
 │   │   │   ├── auth.py            # Authentication dependencies
-│   │   │   └── permissions.py     # Authorization dependencies
+│   │   │   ├── permissions.py     # Authorization dependencies
+│   │   │   └── services.py        # Service singleton injection
 │   │   ├── routes/                # API endpoints
 │   │   │   ├── auth.py            # Authentication routes
 │   │   │   ├── users.py           # User management routes
@@ -131,13 +133,14 @@ backend/
 │   │   ├── config.py              # Application configuration
 │   │   ├── database.py            # Database connection
 │   │   ├── exceptions.py          # Custom exception classes
+│   │   ├── repository_exceptions.py # Repository-level exception hierarchy
 │   │   └── middleware.py          # Custom middleware
 │   │
-│   ├── crud/                       # Database operations
-│   │   ├── base.py                # Generic CRUD base class
-│   │   ├── user.py                # User CRUD operations
-│   │   ├── session.py             # Session CRUD operations
-│   │   └── organization.py        # Organization CRUD
+│   ├── repositories/               # Data access layer
+│   │   ├── base.py                # Generic repository base class
+│   │   ├── user.py                # User repository
+│   │   ├── session.py             # Session repository
+│   │   └── organization.py        # Organization repository
 │   │
 │   ├── models/                     # SQLAlchemy models
 │   │   ├── base.py                # Base model with mixins
@@ -153,8 +156,11 @@ backend/
 │   │   ├── sessions.py            # Session schemas
 │   │   └── organizations.py       # Organization schemas
 │   │
-│   ├── services/                   # Business logic
+│   ├── services/                   # Business logic layer
 │   │   ├── auth_service.py        # Authentication service
+│   │   ├── user_service.py        # User management service
+│   │   ├── session_service.py     # Session management service
+│   │   ├── organization_service.py # Organization service
 │   │   ├── email_service.py       # Email service
 │   │   └── session_cleanup.py     # Background cleanup
 │   │
@@ -168,20 +174,25 @@ backend/
 │
 ├── tests/                          # Test suite
 │   ├── api/                        # Integration tests
-│   ├── crud/                       # CRUD tests
+│   ├── repositories/               # Repository unit tests
+│   ├── services/                   # Service unit tests
 │   ├── models/                     # Model tests
-│   ├── services/                   # Service tests
 │   └── conftest.py                 # Test configuration
 │
 ├── docs/                           # Documentation
 │   ├── ARCHITECTURE.md             # This file
 │   ├── CODING_STANDARDS.md         # Coding standards
+│   ├── COMMON_PITFALLS.md          # Common mistakes to avoid
+│   ├── E2E_TESTING.md              # E2E testing guide
 │   └── FEATURE_EXAMPLE.md          # Feature implementation guide
 │
-├── requirements.txt                # Python dependencies
-├── pytest.ini                      # Pytest configuration
-├── .coveragerc                     # Coverage configuration
-└── alembic.ini                     # Alembic configuration
+├── pyproject.toml                  # Dependencies, tool configs (Ruff, pytest, coverage, Pyright)
+├── uv.lock                         # Locked dependency versions (commit to git)
+├── Makefile                        # Development commands (quality, security, testing)
+├── .pre-commit-config.yaml         # Pre-commit hook configuration
+├── .secrets.baseline               # detect-secrets baseline (known false positives)
+├── alembic.ini                     # Alembic configuration
+└── migrate.py                      # Migration helper script
 ```
 
 ## Layered Architecture
@@ -214,11 +225,11 @@ The application follows a strict 5-layer architecture:
 └──────────────────────────┬──────────────────────────────────┘
                            │ calls
 ┌──────────────────────────▼──────────────────────────────────┐
-│                    CRUD Layer (crud/)                        │
+│              Repository Layer (repositories/)                │
 │  - Database operations                                       │
 │  - Query building                                            │
-│  - Transaction management                                    │
-│  - Error handling                                            │
+│  - Custom repository exceptions                              │
+│  - No business logic                                         │
 └──────────────────────────┬──────────────────────────────────┘
                            │ uses
 ┌──────────────────────────▼──────────────────────────────────┐
@@ -262,7 +273,7 @@ async def get_current_user_info(
 
 **Rules**:
 - Should NOT contain business logic
-- Should NOT directly perform database operations (use CRUD or services)
+- Should NOT directly call repositories (use services injected via `dependencies/services.py`)
 - Must validate all input via Pydantic schemas
 - Must specify response models
 - Should apply appropriate rate limits
@@ -279,9 +290,9 @@ async def get_current_user_info(
 
 **Example**:
 ```python
-def get_current_user(
+async def get_current_user(
     token: str = Depends(oauth2_scheme),
-    db: Session = Depends(get_db)
+    db: AsyncSession = Depends(get_db)
 ) -> User:
     """
     Extract and validate user from JWT token.
@@ -295,7 +306,7 @@ def get_current_user(
     except Exception:
         raise AuthenticationError("Invalid authentication credentials")
 
-    user = user_crud.get(db, id=user_id)
+    user = await user_repo.get(db, id=user_id)
     if not user:
         raise AuthenticationError("User not found")
 
@@ -313,7 +324,7 @@ def get_current_user(
 **Responsibility**: Implement complex business logic
 
 **Key Functions**:
-- Orchestrate multiple CRUD operations
+- Orchestrate multiple repository operations
 - Implement business rules
 - Handle external service integration
 - Coordinate transactions
@@ -323,9 +334,9 @@ def get_current_user(
 class AuthService:
     """Authentication service with business logic."""
 
-    def login(
+    async def login(
         self,
-        db: Session,
+        db: AsyncSession,
         email: str,
         password: str,
         request: Request
@@ -339,8 +350,8 @@ class AuthService:
         3. Generate tokens
         4. Return tokens and user info
         """
-        # Validate credentials
-        user = user_crud.get_by_email(db, email=email)
+        # Validate credentials via repository
+        user = await user_repo.get_by_email(db, email=email)
         if not user or not verify_password(password, user.hashed_password):
             raise AuthenticationError("Invalid credentials")
 
@@ -350,11 +361,10 @@ class AuthService:
         # Extract device info
         device_info = extract_device_info(request)
 
-        # Create session
-        session = session_crud.create_session(
+        # Create session via repository
+        session = await session_repo.create(
             db,
-            user_id=user.id,
-            device_info=device_info
+            obj_in=SessionCreate(user_id=user.id, **device_info)
         )
 
         # Generate tokens
@@ -373,75 +383,60 @@ class AuthService:
 
 **Rules**:
 - Contains business logic, not just data operations
-- Can call multiple CRUD operations
+- Can call multiple repository operations
 - Should handle complex workflows
 - Must maintain data consistency
 - Should use transactions when needed
 
-#### 4. CRUD Layer (`app/crud/`)
+#### 4. Repository Layer (`app/repositories/`)
 
-**Responsibility**: Database operations and queries
+**Responsibility**: Database operations and queries — no business logic
 
 **Key Functions**:
 - Create, read, update, delete operations
 - Build database queries
-- Handle database errors
+- Raise custom repository exceptions (`DuplicateEntryError`, `IntegrityConstraintError`)
 - Manage soft deletes
 - Implement pagination and filtering
 
 **Example**:
 ```python
-class CRUDSession(CRUDBase[UserSession, SessionCreate, SessionUpdate]):
-    """CRUD operations for user sessions."""
+class SessionRepository(RepositoryBase[UserSession, SessionCreate, SessionUpdate]):
+    """Repository for user sessions — database operations only."""
 
-    def get_by_jti(self, db: Session, jti: UUID) -> Optional[UserSession]:
+    async def get_by_jti(self, db: AsyncSession, *, jti: str) -> UserSession | None:
         """Get session by refresh token JTI."""
-        try:
-            return (
-                db.query(UserSession)
-                .filter(UserSession.refresh_token_jti == jti)
-                .first()
-            )
-        except Exception as e:
-            logger.error(f"Error getting session by JTI: {str(e)}")
-            return None
+        result = await db.execute(
+            select(UserSession).where(UserSession.refresh_token_jti == jti)
+        )
+        return result.scalar_one_or_none()
 
-    def get_active_by_jti(
-        self,
-        db: Session,
-        jti: UUID
-    ) -> Optional[UserSession]:
-        """Get active session by refresh token JTI."""
-        session = self.get_by_jti(db, jti=jti)
-        if session and session.is_active and not session.is_expired:
-            return session
-        return None
-
-    def deactivate(self, db: Session, session_id: UUID) -> bool:
+    async def deactivate(self, db: AsyncSession, *, session_id: UUID) -> bool:
         """Deactivate a session (logout)."""
         try:
-            session = self.get(db, id=session_id)
+            session = await self.get(db, id=session_id)
             if not session:
                 return False
 
             session.is_active = False
-            db.commit()
+            await db.commit()
             logger.info(f"Session {session_id} deactivated")
             return True
 
         except Exception as e:
-            db.rollback()
+            await db.rollback()
             logger.error(f"Error deactivating session: {str(e)}")
             return False
 ```
 
 **Rules**:
 - Should NOT contain business logic
-- Must handle database exceptions
-- Must use parameterized queries (SQLAlchemy does this)
+- Must raise custom repository exceptions (not raw `ValueError`/`IntegrityError`)
+- Must use async SQLAlchemy 2.0 `select()` API (never `db.query()`)
 - Should log all database errors
 - Must rollback on errors
 - Should use soft deletes when possible
+- **Never imported directly by routes** — always called through services
 
 #### 5. Data Layer (`app/models/` + `app/schemas/`)
 
@@ -546,51 +541,23 @@ SessionLocal = sessionmaker(
 #### Dependency Injection Pattern
 
 ```python
-def get_db() -> Generator[Session, None, None]:
+async def get_db() -> AsyncGenerator[AsyncSession, None]:
     """
-    Database session dependency for FastAPI routes.
+    Async database session dependency for FastAPI routes.
 
-    Automatically commits on success, rolls back on error.
+    The session is passed to service methods; commit/rollback is
+    managed inside service or repository methods.
     """
-    db = SessionLocal()
-    try:
+    async with AsyncSessionLocal() as db:
         yield db
-    finally:
-        db.close()
 
-# Usage in routes
+# Usage in routes — always through a service, never direct repository
 @router.get("/users")
-def list_users(db: Session = Depends(get_db)):
-    return user_crud.get_multi(db)
-```
-
-#### Context Manager Pattern
-
-```python
-@contextmanager
-def transaction_scope() -> Generator[Session, None, None]:
-    """
-    Context manager for database transactions.
-
-    Use for complex operations requiring multiple steps.
-    Automatically commits on success, rolls back on error.
-    """
-    db = SessionLocal()
-    try:
-        yield db
-        db.commit()
-    except Exception:
-        db.rollback()
-        raise
-    finally:
-        db.close()
-
-# Usage in services
-def complex_operation():
-    with transaction_scope() as db:
-        user = user_crud.create(db, obj_in=user_data)
-        session = session_crud.create(db, session_data)
-        return user, session
+async def list_users(
+    user_service: UserService = Depends(get_user_service),
+    db: AsyncSession = Depends(get_db),
+):
+    return await user_service.get_users(db)
 ```
 
 ### Model Mixins
@@ -782,22 +749,15 @@ def get_profile(
 
 ```python
 @router.delete("/sessions/{session_id}")
-def revoke_session(
+async def revoke_session(
     session_id: UUID,
     current_user: User = Depends(get_current_user),
-    db: Session = Depends(get_db)
+    session_service: SessionService = Depends(get_session_service),
+    db: AsyncSession = Depends(get_db),
 ):
     """Users can only revoke their own sessions."""
-    session = session_crud.get(db, id=session_id)
-
-    if not session:
-        raise NotFoundError("Session not found")
-
-    # Check ownership
-    if session.user_id != current_user.id:
-        raise AuthorizationError("You can only revoke your own sessions")
-
-    session_crud.deactivate(db, session_id=session_id)
+    # SessionService verifies ownership and raises NotFoundError / AuthorizationError
+    await session_service.revoke_session(db, session_id=session_id, user_id=current_user.id)
     return MessageResponse(success=True, message="Session revoked")
 ```
 
@@ -818,6 +778,84 @@ def add_member(
     pass
 ```
 
+### OAuth Integration
+
+The system supports two OAuth modes:
+
+#### OAuth Consumer Mode (Social Login)
+
+Users can authenticate via Google or GitHub OAuth providers:
+
+```python
+# Get authorization URL with PKCE support
+GET /oauth/authorize/{provider}?redirect_uri=https://yourapp.com/callback
+
+# Handle callback and exchange code for tokens
+POST /oauth/callback/{provider}
+{
+    "code": "authorization_code_from_provider",
+    "state": "csrf_state_token"
+}
+```
+
+**Security Features:**
+- PKCE (S256) for Google
+- State parameter for CSRF protection
+- Nonce for Google OIDC replay attack prevention
+- Google ID token signature verification via JWKS
+- Email normalization to prevent account duplication
+- Auto-linking by email (configurable)
+
+#### OAuth Provider Mode (MCP Integration)
+
+Full OAuth 2.0 Authorization Server for third-party clients (RFC compliant):
+
+```
+┌─────────────┐                              ┌─────────────┐
+│ MCP Client  │                              │   Backend   │
+└──────┬──────┘                              └──────┬──────┘
+       │                                             │
+       │  GET /.well-known/oauth-authorization-server│
+       │─────────────────────────────────────────────>│
+       │                 {metadata}                  │
+       │<─────────────────────────────────────────────│
+       │                                             │
+       │  GET /oauth/provider/authorize              │
+       │  ?response_type=code&client_id=...          │
+       │  &redirect_uri=...&code_challenge=...       │
+       │─────────────────────────────────────────────>│
+       │                                             │
+       │              (User consents)                │
+       │                                             │
+       │  302 redirect_uri?code=AUTH_CODE&state=...  │
+       │<─────────────────────────────────────────────│
+       │                                             │
+       │  POST /oauth/provider/token                 │
+       │  {grant_type=authorization_code,            │
+       │   code=AUTH_CODE, code_verifier=...}        │
+       │─────────────────────────────────────────────>│
+       │                                             │
+       │  {access_token, refresh_token, expires_in}  │
+       │<─────────────────────────────────────────────│
+       │                                             │
+```
+
+**Endpoints:**
+- `GET /.well-known/oauth-authorization-server` - RFC 8414 metadata
+- `GET /oauth/provider/authorize` - Authorization endpoint
+- `POST /oauth/provider/token` - Token endpoint (authorization_code, refresh_token)
+- `POST /oauth/provider/revoke` - RFC 7009 token revocation
+- `POST /oauth/provider/introspect` - RFC 7662 token introspection
+
+**Security Features:**
+- PKCE S256 required for public clients (plain method rejected)
+- Authorization codes are single-use with 10-minute expiry
+- Code reuse detection triggers security incident (all tokens revoked)
+- Refresh token rotation on use
+- Opaque refresh tokens (hashed in database)
+- JWT access tokens with standard claims
+- Consent management per client
+
 ## Error Handling
 
 ### Exception Hierarchy
@@ -983,23 +1021,27 @@ from app.services.session_cleanup import cleanup_expired_sessions
 
 scheduler = AsyncIOScheduler()
 
-@app.on_event("startup")
-async def startup_event():
-    """Start background jobs on application startup."""
-    if not settings.IS_TEST:  # Don't run in tests
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    """Application lifespan context manager."""
+    # Startup
+    if os.getenv("IS_TEST", "False") != "True":
         scheduler.add_job(
             cleanup_expired_sessions,
             "cron",
             hour=2,  # Run at 2 AM daily
-            id="cleanup_expired_sessions"
+            id="cleanup_expired_sessions",
+            replace_existing=True,
         )
         scheduler.start()
         logger.info("Background jobs started")
 
-@app.on_event("shutdown")
-async def shutdown_event():
-    """Stop background jobs on application shutdown."""
-    scheduler.shutdown()
+    yield
+
+    # Shutdown
+    if os.getenv("IS_TEST", "False") != "True":
+        scheduler.shutdown()
+    await close_async_db()  # Dispose database engine connections
 ```
 
 ### Job Implementation
@@ -1014,8 +1056,8 @@ async def cleanup_expired_sessions():
     Runs daily at 2 AM. Removes sessions expired for more than 30 days.
     """
     try:
-        with transaction_scope() as db:
-            count = session_crud.cleanup_expired(db, keep_days=30)
+        async with AsyncSessionLocal() as db:
+            count = await session_repo.cleanup_expired(db, keep_days=30)
             logger.info(f"Cleaned up {count} expired sessions")
     except Exception as e:
         logger.error(f"Error cleaning up sessions: {str(e)}", exc_info=True)
@@ -1032,7 +1074,7 @@ async def cleanup_expired_sessions():
         │Integration  │  ← API endpoint tests
         │   Tests     │
         ├─────────────┤
-        │   Unit      │  ← CRUD, services, utilities
+        │   Unit      │  ← repositories, services, utilities
         │   Tests     │
         └─────────────┘
 ```
@@ -1127,6 +1169,8 @@ app.add_middleware(
 
 ## Performance Considerations
 
+> 📖 For the full benchmarking guide (how to run, read results, write new benchmarks, and manage baselines), see **[BENCHMARKS.md](BENCHMARKS.md)**.
+
 ### Database Connection Pooling
 
 - Pool size: 20 connections

backend/docs/BENCHMARKS.md

@@ -0,0 +1,311 @@
+# Performance Benchmarks Guide
+
+Automated performance benchmarking infrastructure using **pytest-benchmark** to detect latency regressions in critical API endpoints.
+
+## Table of Contents
+
+- [Why Benchmark?](#why-benchmark)
+- [Quick Start](#quick-start)
+- [How It Works](#how-it-works)
+- [Understanding Results](#understanding-results)
+- [Test Organization](#test-organization)
+- [Writing Benchmark Tests](#writing-benchmark-tests)
+- [Baseline Management](#baseline-management)
+- [CI/CD Integration](#cicd-integration)
+- [Troubleshooting](#troubleshooting)
+
+---
+
+## Why Benchmark?
+
+Performance regressions are silent bugs — they don't break tests or cause errors, but they degrade the user experience over time. Common causes include:
+
+- **Unintended N+1 queries** after adding a relationship
+- **Heavier serialization** after adding new fields to a response model
+- **Middleware overhead** from new security headers or logging
+- **Dependency upgrades** that introduce slower code paths
+
+Without automated benchmarks, these regressions go unnoticed until users complain. Performance benchmarks serve as an **early warning system** — they measure endpoint latency on every run and flag significant deviations from an established baseline.
+
+### What benchmarks give you
+
+| Benefit | Description |
+|---------|-------------|
+| **Regression detection** | Automatically flags when an endpoint becomes significantly slower |
+| **Baseline tracking** | Stores known-good performance numbers for comparison |
+| **Confidence in refactors** | Verify that code changes don't degrade response times |
+| **Visibility** | Makes performance a first-class, measurable quality attribute |
+
+---
+
+## Quick Start
+
+```bash
+# Run benchmarks (no comparison, just see current numbers)
+make benchmark
+
+# Save current results as the baseline
+make benchmark-save
+
+# Run benchmarks and compare against the saved baseline
+make benchmark-check
+```
+
+---
+
+## How It Works
+
+The benchmarking system has three layers:
+
+### 1. pytest-benchmark integration
+
+[pytest-benchmark](https://pytest-benchmark.readthedocs.io/) is a pytest plugin that provides a `benchmark` fixture. It handles:
+
+- **Calibration**: Automatically determines how many iterations to run for statistical significance
+- **Timing**: Uses `time.perf_counter` for high-resolution measurements
+- **Statistics**: Computes min, max, mean, median, standard deviation, IQR, and outlier detection
+- **Comparison**: Compares current results against saved baselines and flags regressions
+
+### 2. Benchmark types
+
+The test suite includes two categories of performance tests:
+
+| Type | How it works | Examples |
+|------|-------------|----------|
+| **pytest-benchmark tests** | Uses the `benchmark` fixture for precise, multi-round timing | `test_health_endpoint_performance`, `test_openapi_schema_performance`, `test_password_hashing_performance`, `test_password_verification_performance`, `test_access_token_creation_performance`, `test_refresh_token_creation_performance`, `test_token_decode_performance` |
+| **Manual latency tests** | Uses `time.perf_counter` with explicit thresholds (for async endpoints that pytest-benchmark doesn't support natively) | `test_login_latency`, `test_get_current_user_latency`, `test_register_latency`, `test_token_refresh_latency`, `test_sessions_list_latency`, `test_user_profile_update_latency` |
+
+### 3. Regression detection
+
+When running `make benchmark-check`, the system:
+
+1. Runs all benchmark tests
+2. Compares results against the saved baseline (`.benchmarks/` directory)
+3. **Fails the build** if any test's mean time exceeds **200%** of the baseline (i.e., 3× slower)
+
+The `200%` threshold in `--benchmark-compare-fail=mean:200%` means "fail if the mean increased by more than 200% relative to the baseline." This is deliberately generous to avoid false positives from normal run-to-run variance while still catching real regressions.
+
+---
+
+## Understanding Results
+
+A typical benchmark output looks like this:
+
+```
+--------------------------------------------------------------------------------------- benchmark: 2 tests --------------------------------------------------------------------------------------
+Name (time in ms)                       Min               Max              Mean            StdDev            Median               IQR            Outliers       OPS            Rounds  Iterations
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+test_health_endpoint_performance     0.9841 (1.0)      1.5513 (1.0)      1.1390 (1.0)      0.1098 (1.0)      1.1151 (1.0)      0.1672 (1.0)          39;2  877.9666 (1.0)         133           1
+test_openapi_schema_performance      1.6523 (1.68)     2.0892 (1.35)     1.7843 (1.57)     0.1553 (1.41)     1.7200 (1.54)     0.1727 (1.03)          2;0  560.4471 (0.64)         10           1
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+```
+
+### Column reference
+
+| Column | Meaning |
+|--------|---------|
+| **Min** | Fastest single execution |
+| **Max** | Slowest single execution |
+| **Mean** | Average across all rounds — the primary metric for regression detection |
+| **StdDev** | How much results vary between rounds (lower = more stable) |
+| **Median** | Middle value, less sensitive to outliers than mean |
+| **IQR** | Interquartile range — spread of the middle 50% of results |
+| **Outliers** | Format `A;B` — A = within 1 StdDev, B = within 1.5 IQR from quartiles |
+| **OPS** | Operations per second (`1 / Mean`) |
+| **Rounds** | How many times the test was executed (auto-calibrated) |
+| **Iterations** | Iterations per round (usually 1 for ms-scale tests) |
+
+### The ratio numbers `(1.0)`, `(1.68)`, etc.
+
+These show how each test compares **to the best result in that column**. The fastest test is always `(1.0)`, and others show their relative factor. For example, `(1.68)` means "1.68× slower than the fastest."
+
+### Color coding
+
+- **Green**: The fastest (best) value in each column
+- **Red**: The slowest (worst) value in each column
+
+This is a **relative ranking within the current run** — red does NOT mean the test failed or that performance is bad. It simply highlights which endpoint is the slower one in the group.
+
+### What's "normal"?
+
+For this project's current endpoints:
+
+| Test | Expected range | Why |
+|------|---------------|-----|
+| `GET /health` | ~1–1.5ms | Minimal logic, mocked DB check |
+| `GET /api/v1/openapi.json` | ~1.5–2.5ms | Serializes entire API schema |
+| `get_password_hash` | ~200ms | CPU-bound bcrypt hashing |
+| `verify_password` | ~200ms | CPU-bound bcrypt verification |
+| `create_access_token` | ~17–20µs | JWT encoding with HMAC-SHA256 |
+| `create_refresh_token` | ~17–20µs | JWT encoding with HMAC-SHA256 |
+| `decode_token` | ~20–25µs | JWT decoding and claim validation |
+| `POST /api/v1/auth/login` | < 500ms threshold | Includes bcrypt password verification |
+| `POST /api/v1/auth/register` | < 500ms threshold | Includes bcrypt password hashing |
+| `POST /api/v1/auth/refresh` | < 200ms threshold | Token rotation + DB session update |
+| `GET /api/v1/users/me` | < 200ms threshold | DB lookup + token validation |
+| `GET /api/v1/sessions/me` | < 200ms threshold | Session list query + token validation |
+| `PATCH /api/v1/users/me` | < 200ms threshold | DB update + token validation |
+
+---
+
+## Test Organization
+
+```
+backend/tests/
+├── benchmarks/
+│   └── test_endpoint_performance.py   # All performance benchmark tests
+│
+backend/.benchmarks/                    # Saved baselines (auto-generated)
+└── Linux-CPython-3.12-64bit/
+    └── 0001_baseline.json             # Platform-specific baseline file
+```
+
+### Test markers
+
+All benchmark tests use the `@pytest.mark.benchmark` marker. The `--benchmark-only` flag ensures that only tests using the `benchmark` fixture are executed during benchmark runs, while manual latency tests (async) are skipped.
+
+---
+
+## Writing Benchmark Tests
+
+### Stateless endpoint (using pytest-benchmark fixture)
+
+```python
+import pytest
+from fastapi.testclient import TestClient
+
+def test_my_endpoint_performance(sync_client, benchmark):
+    """Benchmark: GET /my-endpoint should respond within acceptable latency."""
+    result = benchmark(sync_client.get, "/my-endpoint")
+    assert result.status_code == 200
+```
+
+The `benchmark` fixture handles all timing, calibration, and statistics automatically. Just pass it the callable and arguments.
+
+### Async / DB-dependent endpoint (manual timing)
+
+For async endpoints that require database access, use manual timing with an explicit threshold:
+
+```python
+import time
+import pytest
+
+MAX_RESPONSE_MS = 300
+
+@pytest.mark.asyncio
+async def test_my_async_endpoint_latency(client, setup_fixture):
+    """Performance: endpoint must respond under threshold."""
+    iterations = 5
+    total_ms = 0.0
+
+    for _ in range(iterations):
+        start = time.perf_counter()
+        response = await client.get("/api/v1/my-endpoint")
+        elapsed_ms = (time.perf_counter() - start) * 1000
+        total_ms += elapsed_ms
+        assert response.status_code == 200
+
+    mean_ms = total_ms / iterations
+    assert mean_ms < MAX_RESPONSE_MS, (
+        f"Latency regression: {mean_ms:.1f}ms exceeds {MAX_RESPONSE_MS}ms threshold"
+    )
+```
+
+### Guidelines for new benchmarks
+
+1. **Benchmark critical paths** — endpoints users hit frequently or where latency matters most
+2. **Mock external dependencies** for stateless tests to isolate endpoint overhead
+3. **Set generous thresholds** for manual tests — account for CI variability
+4. **Keep benchmarks fast** — they run on every check, so avoid heavy setup
+
+---
+
+## Baseline Management
+
+### Saving a baseline
+
+```bash
+make benchmark-save
+```
+
+This runs all benchmarks and saves results to `.benchmarks/<platform>/0001_baseline.json`. The baseline captures:
+- Mean, min, max, median, stddev for each test
+- Machine info (CPU, OS, Python version)
+- Timestamp
+
+### Comparing against baseline
+
+```bash
+make benchmark-check
+```
+
+If no baseline exists, this command automatically creates one and prints a warning. On subsequent runs, it compares current results against the saved baseline.
+
+### When to update the baseline
+
+- **After intentional performance changes** (e.g., you optimized an endpoint — save the new, faster baseline)
+- **After infrastructure changes** (e.g., new CI runner, different hardware)
+- **After adding new benchmark tests** (the new tests need a baseline entry)
+
+```bash
+# Update the baseline after intentional changes
+make benchmark-save
+```
+
+### Version control
+
+The `.benchmarks/` directory can be committed to version control so that CI pipelines can compare against a known-good baseline. However, since benchmark results are machine-specific, you may prefer to generate baselines in CI rather than committing local results.
+
+---
+
+## CI/CD Integration
+
+Add benchmark checking to your CI pipeline to catch regressions on every PR:
+
+```yaml
+# Example GitHub Actions step
+- name: Performance regression check
+  run: |
+    cd backend
+    make benchmark-save   # Create baseline from main branch
+    # ... apply PR changes ...
+    make benchmark-check  # Compare PR against baseline
+```
+
+A more robust approach:
+1. Save the baseline on the `main` branch after each merge
+2. On PR branches, run `make benchmark-check` against the `main` baseline
+3. The pipeline fails if any endpoint regresses beyond the 200% threshold
+
+---
+
+## Troubleshooting
+
+### "No benchmark baseline found" warning
+
+```
+⚠️  No benchmark baseline found. Run 'make benchmark-save' first to create one.
+```
+
+This means no baseline file exists yet. The command will auto-create one. Future runs of `make benchmark-check` will compare against it.
+
+### Machine info mismatch warning
+
+```
+WARNING: benchmark machine_info is different
+```
+
+This is expected when comparing baselines generated on a different machine or OS. The comparison still works, but absolute numbers may differ. Re-save the baseline on the current machine if needed.
+
+### High variance (large StdDev)
+
+If StdDev is high relative to the Mean, results may be unreliable. Common causes:
+- System under load during benchmark run
+- Garbage collection interference
+- Thermal throttling
+
+Try running benchmarks on an idle system or increasing `min_rounds` in `pyproject.toml`.
+
+### Only 7 of 13 tests run
+
+The async tests (`test_login_latency`, `test_get_current_user_latency`, `test_register_latency`, `test_token_refresh_latency`, `test_sessions_list_latency`, `test_user_profile_update_latency`) are skipped during `--benchmark-only` runs because they don't use the `benchmark` fixture. They run as part of the normal test suite (`make test`) with manual threshold assertions.

backend/docs/CODING_STANDARDS.md

@@ -8,6 +8,7 @@ This document outlines the coding standards and best practices for the FastAPI b
 - [Code Organization](#code-organization)
 - [Naming Conventions](#naming-conventions)
 - [Error Handling](#error-handling)
+- [Data Models and Migrations](#data-models-and-migrations)
 - [Database Operations](#database-operations)
 - [API Endpoints](#api-endpoints)
 - [Authentication & Security](#authentication--security)
@@ -74,15 +75,14 @@ def create_user(db: Session, user_in: UserCreate) -> User:
 ### 4. Code Formatting
 
 Use automated formatters:
-- **Black**: Code formatting
-- **isort**: Import sorting
-- **flake8**: Linting
+- **Ruff**: Code formatting and linting (replaces Black, isort, flake8)
+- **pyright**: Static type checking
 
-Run before committing:
+Run before committing (or use `make validate`):
 ```bash
-black app tests
-isort app tests
-flake8 app tests
+uv run ruff format app tests
+uv run ruff check app tests
+uv run pyright app
 ```
 
 ## Code Organization
@@ -93,19 +93,17 @@ Follow the 5-layer architecture strictly:
 
 ```
 API Layer (routes/)
-    ↓ calls
-Dependencies (dependencies/)
-    ↓ injects
+    ↓ calls (via service injected from dependencies/services.py)
 Service Layer (services/)
     ↓ calls
-CRUD Layer (crud/)
+Repository Layer (repositories/)
     ↓ uses
 Models & Schemas (models/, schemas/)
 ```
 
 **Rules:**
-- Routes should NOT directly call CRUD operations (use services when business logic is needed)
-- CRUD operations should NOT contain business logic
+- Routes must NEVER import repositories directly — always use a service
+- Services call repositories; repositories contain only database operations
 - Models should NOT import from higher layers
 - Each layer should only depend on the layer directly below it
 
@@ -124,7 +122,7 @@ from sqlalchemy.orm import Session
 
 # 3. Local application imports
 from app.api.dependencies.auth import get_current_user
-from app.crud import user_crud
+from app.api.dependencies.services import get_user_service
 from app.models.user import User
 from app.schemas.users import UserResponse, UserCreate
 ```
@@ -216,7 +214,7 @@ if not user:
 
 ### Error Handling Pattern
 
-Always follow this pattern in CRUD operations (Async version):
+Always follow this pattern in repository operations (Async version):
 
 ```python
 from sqlalchemy.exc import IntegrityError, OperationalError, DataError
@@ -282,9 +280,154 @@ All error responses follow this structure:
 }
 ```
 
+## Data Models and Migrations
+
+### Model Definition Best Practices
+
+To ensure Alembic autogenerate works reliably without drift, follow these rules:
+
+#### 1. Simple Indexes: Use Column-Level or `__table_args__`, Not Both
+
+```python
+# ❌ BAD - Creates DUPLICATE indexes with different names
+class User(Base):
+    role = Column(String(50), index=True)  # Creates ix_users_role
+
+    __table_args__ = (
+        Index("ix_user_role", "role"),  # Creates ANOTHER index!
+    )
+
+# ✅ GOOD - Choose ONE approach
+class User(Base):
+    role = Column(String(50))  # No index=True
+
+    __table_args__ = (
+        Index("ix_user_role", "role"),  # Single index with explicit name
+    )
+
+# ✅ ALSO GOOD - For simple single-column indexes
+class User(Base):
+    role = Column(String(50), index=True)  # Auto-named ix_users_role
+```
+
+#### 2. Composite Indexes: Always Use `__table_args__`
+
+```python
+class UserOrganization(Base):
+    __tablename__ = "user_organizations"
+
+    user_id = Column(UUID, nullable=False)
+    organization_id = Column(UUID, nullable=False)
+    is_active = Column(Boolean, default=True, nullable=False, index=True)
+
+    __table_args__ = (
+        Index("ix_user_org_user_active", "user_id", "is_active"),
+        Index("ix_user_org_org_active", "organization_id", "is_active"),
+    )
+```
+
+#### 3. Functional/Partial Indexes: Use `ix_perf_` Prefix
+
+Alembic **cannot** auto-detect:
+- **Functional indexes**: `LOWER(column)`, `UPPER(column)`, expressions
+- **Partial indexes**: Indexes with `WHERE` clauses
+
+**Solution**: Use the `ix_perf_` naming prefix. Any index with this prefix is automatically excluded from autogenerate by `env.py`.
+
+```python
+# In migration file (NOT in model) - use ix_perf_ prefix:
+op.create_index(
+    "ix_perf_users_email_lower",  # <-- ix_perf_ prefix!
+    "users",
+    [sa.text("LOWER(email)")],  # Functional
+    postgresql_where=sa.text("deleted_at IS NULL"),  # Partial
+)
+```
+
+**No need to update `env.py`** - the prefix convention handles it automatically:
+
+```python
+# env.py - already configured:
+def include_object(object, name, type_, reflected, compare_to):
+    if type_ == "index" and name:
+        if name.startswith("ix_perf_"):  # Auto-excluded!
+            return False
+    return True
+```
+
+**To add new performance indexes:**
+1. Create a new migration file
+2. Name your indexes with `ix_perf_` prefix
+3. Done - Alembic will ignore them automatically
+
+#### 4. Use Correct Types
+
+```python
+# ✅ GOOD - PostgreSQL-native types
+from sqlalchemy.dialects.postgresql import JSONB, UUID
+
+class User(Base):
+    id = Column(UUID(as_uuid=True), primary_key=True)
+    preferences = Column(JSONB)  # Not JSON!
+
+# ❌ BAD - Generic types may cause migration drift
+from sqlalchemy import JSON
+preferences = Column(JSON)  # May detect as different from JSONB
+```
+
+### Migration Workflow
+
+#### Creating Migrations
+
+```bash
+# Generate autogenerate migration:
+python migrate.py generate "Add new field"
+
+# Or inside Docker:
+docker exec -w /app backend uv run alembic revision --autogenerate -m "Add new field"
+
+# Apply migration:
+python migrate.py apply
+# Or: docker exec -w /app backend uv run alembic upgrade head
+```
+
+#### Testing for Drift
+
+After any model changes, verify no unintended drift:
+
+```bash
+# Generate test migration
+docker exec -w /app backend uv run alembic revision --autogenerate -m "test_drift"
+
+# Check the generated file - should be empty (just 'pass')
+# If it has operations, investigate why
+
+# Delete test file
+rm backend/app/alembic/versions/*_test_drift.py
+```
+
+#### Migration File Structure
+
+```
+backend/app/alembic/versions/
+├── cbddc8aa6eda_initial_models.py    # Auto-generated, tracks all models
+├── 0002_performance_indexes.py        # Manual, functional/partial indexes
+└── __init__.py
+```
+
+### Summary: What Goes Where
+
+| Index Type | In Model? | Alembic Detects? | Where to Define |
+|------------|-----------|------------------|-----------------|
+| Simple column (`index=True`) | Yes | Yes | Column definition |
+| Composite (`col1, col2`) | Yes | Yes | `__table_args__` |
+| Unique composite | Yes | Yes | `__table_args__` with `unique=True` |
+| Functional (`LOWER(col)`) | No | No | Migration with `ix_perf_` prefix |
+| Partial (`WHERE ...`) | No | No | Migration with `ix_perf_` prefix |
+
 ## Database Operations
 
-### Async CRUD Pattern
+### Async Repository Pattern
 
 **IMPORTANT**: This application uses **async SQLAlchemy** with modern patterns for better performance and testability.
 
@@ -296,19 +439,19 @@ All error responses follow this structure:
 4. **Testability**: Easy to mock and test
 5. **Consistent Ordering**: Always order queries for pagination
 
-### Use the Async CRUD Base Class
+### Use the Async Repository Base Class
 
-Always inherit from `CRUDBase` for database operations:
+Always inherit from `RepositoryBase` for database operations:
 
 ```python
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy import select
-from app.crud.base import CRUDBase
+from app.repositories.base import RepositoryBase
 from app.models.user import User
 from app.schemas.users import UserCreate, UserUpdate
 
-class CRUDUser(CRUDBase[User, UserCreate, UserUpdate]):
-    """CRUD operations for User model."""
+class UserRepository(RepositoryBase[User, UserCreate, UserUpdate]):
+    """Repository for User model — database operations only."""
 
     async def get_by_email(
         self,
@@ -321,7 +464,7 @@ class CRUDUser(CRUDBase[User, UserCreate, UserUpdate]):
         )
         return result.scalar_one_or_none()
 
-user_crud = CRUDUser(User)
+user_repo = UserRepository(User)
 ```
 
 **Key Points:**
@@ -330,6 +473,7 @@ user_crud = CRUDUser(User)
 - Use `await db.execute()` for queries
 - Use `.scalar_one_or_none()` instead of `.first()`
 - Use `T | None` instead of `Optional[T]`
+- Repository instances are used internally by services — never import them in routes
 
 ### Modern SQLAlchemy Patterns
 
@@ -417,13 +561,13 @@ async def create_user(
     The database session is automatically managed by FastAPI.
     Commit on success, rollback on error.
     """
-    return await user_crud.create(db, obj_in=user_in)
+    return await user_service.create_user(db, obj_in=user_in)
 ```
 
 **Key Points:**
 - Route functions must be `async def`
 - Database parameter is `AsyncSession`
-- Always `await` CRUD operations
+- Always `await` repository operations
 
 #### In Services (Multiple Operations)
 
@@ -436,12 +580,11 @@ async def complex_operation(
     """
     Perform multiple database operations atomically.
 
-    The session automatically commits on success or rolls back on error.
+    Services call repositories; commit/rollback is handled inside
+    each repository method.
     """
-    user = await user_crud.create(db, obj_in=user_data)
-    session = await session_crud.create(db, obj_in=session_data)
-
-    # Commit is handled by the route's dependency
+    user = await user_repo.create(db, obj_in=user_data)
+    session = await session_repo.create(db, obj_in=session_data)
     return user, session
 ```
 
@@ -451,10 +594,10 @@ Prefer soft deletes over hard deletes for audit trails:
 
 ```python
 # Good - Soft delete (sets deleted_at)
-await user_crud.soft_delete(db, id=user_id)
+await user_repo.soft_delete(db, id=user_id)
 
 # Acceptable only when required - Hard delete
-user_crud.remove(db, id=user_id)
+await user_repo.remove(db, id=user_id)
 ```
 
 ### Query Patterns
@@ -594,9 +737,10 @@ Always implement pagination for list endpoints:
 from app.schemas.common import PaginationParams, PaginatedResponse
 
 @router.get("/users", response_model=PaginatedResponse[UserResponse])
-def list_users(
+async def list_users(
     pagination: PaginationParams = Depends(),
-    db: Session = Depends(get_db)
+    user_service: UserService = Depends(get_user_service),
+    db: AsyncSession = Depends(get_db),
 ):
     """
     List all users with pagination.
@@ -604,10 +748,8 @@ def list_users(
     Default page size: 20
     Maximum page size: 100
     """
-    users, total = user_crud.get_multi_with_total(
-        db,
-        skip=pagination.offset,
-        limit=pagination.limit
+    users, total = await user_service.get_users(
+        db, skip=pagination.offset, limit=pagination.limit
     )
     return PaginatedResponse(data=users, pagination=pagination.create_meta(total))
 ```
@@ -670,19 +812,17 @@ def admin_route(
     pass
 
 # Check ownership
-def delete_resource(
+async def delete_resource(
     resource_id: UUID,
     current_user: User = Depends(get_current_user),
-    db: Session = Depends(get_db)
+    resource_service: ResourceService = Depends(get_resource_service),
+    db: AsyncSession = Depends(get_db),
 ):
-    resource = resource_crud.get(db, id=resource_id)
-    if not resource:
-        raise NotFoundError("Resource not found")
-
-    if resource.user_id != current_user.id and not current_user.is_superuser:
-        raise AuthorizationError("You can only delete your own resources")
-
-    resource_crud.remove(db, id=resource_id)
+    # Service handles ownership check and raises appropriate errors
+    await resource_service.delete_resource(
+        db, resource_id=resource_id, user_id=current_user.id,
+        is_superuser=current_user.is_superuser,
+    )
 ```
 
 ### Input Validation
@@ -716,9 +856,9 @@ tests/
 ├── api/                     # Integration tests
 │   ├── test_users.py
 │   └── test_auth.py
-├── crud/                    # Unit tests for CRUD
-├── models/                  # Model tests
-└── services/                # Service tests
+├── repositories/            # Unit tests for repositories
+├── services/                # Unit tests for services
+└── models/                  # Model tests
 ```
 
 ### Async Testing with pytest-asyncio
@@ -781,7 +921,7 @@ async def test_user(db_session: AsyncSession) -> User:
 @pytest.mark.asyncio
 async def test_get_user(db_session: AsyncSession, test_user: User):
     """Test retrieving a user by ID."""
-    user = await user_crud.get(db_session, id=test_user.id)
+    user = await user_repo.get(db_session, id=test_user.id)
     assert user is not None
     assert user.email == test_user.email
 ```

backend/docs/COMMON_PITFALLS.md

@@ -334,14 +334,14 @@ def login(request: Request, credentials: OAuth2PasswordRequestForm):
 # ❌ WRONG - Returns password hash!
 @router.get("/users/{user_id}")
 def get_user(user_id: UUID, db: Session = Depends(get_db)) -> User:
-    return user_crud.get(db, id=user_id)  # Returns ORM model with ALL fields!
+    return user_repo.get(db, id=user_id)  # Returns ORM model with ALL fields!
 ```
 
 ```python
 # ✅ CORRECT - Use response schema
 @router.get("/users/{user_id}", response_model=UserResponse)
 def get_user(user_id: UUID, db: Session = Depends(get_db)):
-    user = user_crud.get(db, id=user_id)
+    user = user_repo.get(db, id=user_id)
     if not user:
         raise HTTPException(status_code=404, detail="User not found")
     return user  # Pydantic filters to only UserResponse fields
@@ -506,8 +506,8 @@ def revoke_session(
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db)
 ):
-    session = session_crud.get(db, id=session_id)
-    session_crud.deactivate(db, session_id=session_id)
+    session = session_repo.get(db, id=session_id)
+    session_repo.deactivate(db, session_id=session_id)
     # BUG: User can revoke ANYONE'S session!
     return {"message": "Session revoked"}
 ```
@@ -520,7 +520,7 @@ def revoke_session(
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db)
 ):
-    session = session_crud.get(db, id=session_id)
+    session = session_repo.get(db, id=session_id)
 
     if not session:
         raise NotFoundError("Session not found")
@@ -529,7 +529,7 @@ def revoke_session(
     if session.user_id != current_user.id:
         raise AuthorizationError("You can only revoke your own sessions")
 
-    session_crud.deactivate(db, session_id=session_id)
+    session_repo.deactivate(db, session_id=session_id)
     return {"message": "Session revoked"}
 ```
 
@@ -616,7 +616,43 @@ def create_user(
     return user
 ```
 
-**Rule**: Add type hints to ALL functions. Use `mypy` to enforce type checking.
+**Rule**: Add type hints to ALL functions. Use `pyright` to enforce type checking (`make type-check`).
+
+---
+
+---
+
+### ❌ PITFALL #19: Importing Repositories Directly in Routes
+
+**Issue**: Routes should never call repositories directly. The layered architecture requires all business operations to go through the service layer.
+
+```python
+# ❌ WRONG - Route bypasses service layer
+from app.repositories.session import session_repo
+
+@router.get("/sessions/me")
+async def list_sessions(
+    current_user: User = Depends(get_current_active_user),
+    db: AsyncSession = Depends(get_db),
+):
+    return await session_repo.get_user_sessions(db, user_id=current_user.id)
+```
+
+```python
+# ✅ CORRECT - Route calls service injected via dependency
+from app.api.dependencies.services import get_session_service
+from app.services.session_service import SessionService
+
+@router.get("/sessions/me")
+async def list_sessions(
+    current_user: User = Depends(get_current_active_user),
+    session_service: SessionService = Depends(get_session_service),
+    db: AsyncSession = Depends(get_db),
+):
+    return await session_service.get_user_sessions(db, user_id=current_user.id)
+```
+
+**Rule**: Routes import from `app.api.dependencies.services`, never from `app.repositories.*`. Services are the only callers of repositories.
 
 ---
 
@@ -649,6 +685,11 @@ Use this checklist to catch issues before code review:
 - [ ] Resource ownership verification
 - [ ] CORS configured (no wildcards in production)
 
+### Architecture
+- [ ] Routes never import repositories directly (only services)
+- [ ] Services call repositories; repositories call database only
+- [ ] New service registered in `app/api/dependencies/services.py`
+
 ### Python
 - [ ] Use `==` not `is` for value comparison
 - [ ] No mutable default arguments
@@ -661,21 +702,18 @@ Use this checklist to catch issues before code review:
 
 ### Pre-commit Checks
 
-Add these to your development workflow:
+Add these to your development workflow (or use `make validate`):
 
 ```bash
-# Format code
-black app tests
-isort app tests
+# Format + lint (Ruff replaces Black, isort, flake8)
+uv run ruff format app tests
+uv run ruff check app tests
 
 # Type checking
-mypy app --strict
-
-# Linting
-flake8 app tests
+uv run pyright app
 
 # Run tests
-pytest --cov=app --cov-report=term-missing
+IS_TEST=True uv run pytest --cov=app --cov-report=term-missing
 
 # Check coverage (should be 80%+)
 coverage report --fail-under=80
@@ -693,6 +731,6 @@ Add new entries when:
 
 ---
 
-**Last Updated**: 2025-10-31
-**Issues Cataloged**: 18 common pitfalls
+**Last Updated**: 2026-02-28
+**Issues Cataloged**: 19 common pitfalls
 **Remember**: This document exists because these issues HAVE occurred. Don't skip it.

backend/docs/E2E_TESTING.md

@@ -0,0 +1,348 @@
+# Backend E2E Testing Guide
+
+End-to-end testing infrastructure using **Testcontainers** (real PostgreSQL) and **Schemathesis** (OpenAPI contract testing).
+
+## Table of Contents
+
+- [Quick Start](#quick-start)
+- [Requirements](#requirements)
+- [How It Works](#how-it-works)
+- [Test Organization](#test-organization)
+- [Writing E2E Tests](#writing-e2e-tests)
+- [Running Tests](#running-tests)
+- [Troubleshooting](#troubleshooting)
+- [CI/CD Integration](#cicd-integration)
+
+---
+
+## Quick Start
+
+```bash
+# 1. Install E2E dependencies
+make install-e2e
+
+# 2. Ensure Docker is running
+make check-docker
+
+# 3. Run E2E tests
+make test-e2e
+```
+
+---
+
+## Requirements
+
+### Docker
+
+E2E tests use Testcontainers to spin up real PostgreSQL containers. Docker must be running:
+
+- **macOS/Windows**: Docker Desktop
+- **Linux**: Docker Engine (`sudo systemctl start docker`)
+
+### Dependencies
+
+E2E tests require additional packages beyond the standard dev dependencies:
+
+```bash
+# Install E2E dependencies
+make install-e2e
+
+# Or manually:
+uv sync --extra dev --extra e2e
+```
+
+This installs:
+- `testcontainers[postgres]>=4.0.0` - Docker container management
+- `schemathesis>=3.30.0` - OpenAPI contract testing
+
+---
+
+## How It Works
+
+### Testcontainers
+
+Testcontainers automatically manages Docker containers for tests:
+
+1. **Session-scoped container**: A single PostgreSQL 17 container starts once per test session
+2. **Function-scoped isolation**: Each test gets fresh tables (drop + recreate)
+3. **Automatic cleanup**: Container is destroyed when tests complete
+
+This approach catches bugs that SQLite-based tests miss:
+- PostgreSQL-specific SQL behavior
+- Real constraint violations
+- Actual transaction semantics
+- JSONB column behavior
+
+### Schemathesis
+
+Schemathesis generates test cases from your OpenAPI schema:
+
+1. **Schema loading**: Reads `/api/v1/openapi.json` from your FastAPI app
+2. **Test generation**: Creates test cases for each endpoint
+3. **Response validation**: Verifies responses match documented schema
+
+This catches:
+- Undocumented response codes
+- Schema mismatches (wrong types, missing fields)
+- Edge cases in input validation
+
+---
+
+## Test Organization
+
+```
+backend/tests/
+├── e2e/                          # E2E tests (PostgreSQL, Docker required)
+│   ├── __init__.py
+│   ├── conftest.py               # Testcontainers fixtures
+│   ├── test_api_contracts.py     # Schemathesis schema tests
+│   └── test_database_workflows.py # PostgreSQL workflow tests
+│
+├── api/                          # Integration tests (SQLite, fast)
+├── repositories/                 # Repository unit tests
+└── conftest.py                   # Standard fixtures
+```
+
+### Test Markers
+
+Tests use pytest markers for filtering:
+
+| Marker | Description |
+|--------|-------------|
+| `@pytest.mark.e2e` | End-to-end test requiring Docker |
+| `@pytest.mark.postgres` | PostgreSQL-specific test |
+| `@pytest.mark.schemathesis` | Schemathesis schema test |
+
+---
+
+## Writing E2E Tests
+
+### Basic E2E Test
+
+```python
+import pytest
+from uuid import uuid4
+
+@pytest.mark.e2e
+@pytest.mark.postgres
+@pytest.mark.asyncio
+async def test_user_workflow(e2e_client):
+    """Test user registration with real PostgreSQL."""
+    email = f"test-{uuid4().hex[:8]}@example.com"
+
+    response = await e2e_client.post(
+        "/api/v1/auth/register",
+        json={
+            "email": email,
+            "password": "SecurePassword123!",
+            "first_name": "Test",
+            "last_name": "User",
+        },
+    )
+
+    assert response.status_code in [200, 201]
+    assert response.json()["email"] == email
+```
+
+### Available Fixtures
+
+| Fixture | Scope | Description |
+|---------|-------|-------------|
+| `postgres_container` | session | Raw Testcontainers PostgreSQL container |
+| `async_postgres_url` | session | Asyncpg-compatible connection URL |
+| `e2e_db_session` | function | SQLAlchemy AsyncSession with fresh tables |
+| `e2e_client` | function | httpx AsyncClient connected to real DB |
+
+### Schemathesis Test
+
+```python
+import pytest
+import schemathesis
+from hypothesis import settings, Phase
+
+from app.main import app
+
+schema = schemathesis.from_asgi("/api/v1/openapi.json", app=app)
+
+@pytest.mark.e2e
+@pytest.mark.schemathesis
+@schema.parametrize(endpoint="/api/v1/auth/register")
+@settings(max_examples=20)
+def test_registration_schema(case):
+    """Test registration endpoint conforms to schema."""
+    response = case.call_asgi()
+    case.validate_response(response)
+```
+
+---
+
+## Running Tests
+
+### Commands
+
+```bash
+# Run all E2E tests
+make test-e2e
+
+# Run only Schemathesis schema tests
+make test-e2e-schema
+
+# Run all tests (unit + integration + E2E)
+make test-all
+
+# Check Docker availability
+make check-docker
+```
+
+### Direct pytest
+
+```bash
+# All E2E tests
+IS_TEST=True PYTHONPATH=. uv run pytest tests/e2e/ -v
+
+# Only PostgreSQL tests
+IS_TEST=True PYTHONPATH=. uv run pytest tests/e2e/ -v -m postgres
+
+# Only Schemathesis tests
+IS_TEST=True PYTHONPATH=. uv run pytest tests/e2e/ -v -m schemathesis
+```
+
+---
+
+## Troubleshooting
+
+### Docker Not Running
+
+**Error:**
+```
+Docker is not running!
+E2E tests require Docker to be running.
+```
+
+**Solution:**
+```bash
+# macOS/Windows
+# Open Docker Desktop
+
+# Linux
+sudo systemctl start docker
+```
+
+### Testcontainers Not Installed
+
+**Error:**
+```
+SKIPPED: testcontainers not installed - run: make install-e2e
+```
+
+**Solution:**
+```bash
+make install-e2e
+# Or: uv sync --extra dev --extra e2e
+```
+
+### Container Startup Timeout
+
+**Error:**
+```
+testcontainers.core.waiting_utils.UnexpectedResponse
+```
+
+**Solutions:**
+1. Increase Docker resources (memory, CPU)
+2. Pull the image manually: `docker pull postgres:17-alpine`
+3. Check Docker daemon logs: `docker logs`
+
+### Port Conflicts
+
+**Error:**
+```
+Error starting container: port is already allocated
+```
+
+**Solution:**
+Testcontainers uses random ports, so conflicts are rare. If occurring:
+1. Stop other PostgreSQL containers: `docker stop $(docker ps -q)`
+2. Check for orphaned containers: `docker container prune`
+
+### Ryuk/Reaper Port 8080 Issues
+
+**Error:**
+```
+ConnectionError: Port mapping for container ... and port 8080 is not available
+```
+
+**Solution:**
+This is related to the Testcontainers Reaper (Ryuk) which handles automatic cleanup.
+The `conftest.py` automatically disables Ryuk to avoid this issue. If you still encounter
+this error, ensure you're using the latest conftest.py or set the environment variable:
+
+```bash
+export TESTCONTAINERS_RYUK_DISABLED=true
+```
+
+### Parallel Test Execution Issues
+
+**Error:**
+```
+ScopeMismatch: ... cannot use a higher-scoped fixture 'postgres_container'
+```
+
+**Solution:**
+E2E tests must run sequentially (not in parallel) because they share a session-scoped
+PostgreSQL container. The Makefile commands use `-n 0` to disable parallel execution.
+If running pytest directly, add `-n 0`:
+
+```bash
+IS_TEST=True PYTHONPATH=. uv run pytest tests/e2e/ -v -n 0
+```
+
+---
+
+## CI/CD Integration
+
+### GitHub Actions
+
+A workflow template is provided at `.github/workflows/backend-e2e-tests.yml.template`.
+
+To enable:
+1. Rename to `backend-e2e-tests.yml`
+2. Push to repository
+
+The workflow:
+- Runs on pushes to `main`/`develop` affecting `backend/`
+- Uses `continue-on-error: true` (E2E failures don't block merge)
+- Caches uv dependencies for speed
+
+### Local CI Simulation
+
+```bash
+# Run what CI runs
+make test-all
+```
+
+---
+
+## Best Practices
+
+### DO
+
+- Use unique emails per test: `f"test-{uuid4().hex[:8]}@example.com"`
+- Mark tests with appropriate markers: `@pytest.mark.e2e`
+- Keep E2E tests focused on critical workflows
+- Use `e2e_client` fixture for most tests
+
+### DON'T
+
+- Share state between tests (each test gets fresh tables)
+- Test every endpoint in E2E (use unit tests for edge cases)
+- Skip the `IS_TEST=True` environment variable
+- Run E2E tests without Docker
+
+---
+
+## Further Reading
+
+- [Testcontainers Documentation](https://testcontainers.com/guides/getting-started-with-testcontainers-for-python/)
+- [Schemathesis Documentation](https://schemathesis.readthedocs.io/)
+- [pytest-asyncio Documentation](https://pytest-asyncio.readthedocs.io/)