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

@@ -187,7 +187,7 @@ coverage.xml
 .hypothesis/
 .pytest_cache/
 cover/
-
+backend/.benchmarks
 # Translations
 *.mo
 *.pot
@@ -268,6 +268,7 @@ celerybeat.pid
 .env
 .env.*
 !.env.template
+!.env.demo
 .venv
 env/
 venv/

AGENTS.md

@@ -13,10 +13,10 @@ uv run uvicorn app.main:app --reload  # Start dev server
 
 # Frontend (Node.js)
 cd frontend
-npm install                   # Install dependencies
-npm run dev                   # Start dev server
-npm run generate:api          # Generate API client from OpenAPI
-npm run test:e2e              # Run E2E tests
+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:**
@@ -37,17 +37,17 @@ Default superuser (change in production):
 │   ├── app/
 │   │   ├── api/            # API routes (auth, users, organizations, admin)
 │   │   ├── core/           # Core functionality (auth, config, database)
-│   │   ├── crud/           # Database CRUD operations
+│   │   ├── repositories/   # Repository pattern (database operations)
 │   │   ├── models/         # SQLAlchemy ORM models
 │   │   ├── schemas/        # Pydantic request/response schemas
 │   │   ├── services/       # Business logic layer
 │   │   └── utils/          # Utilities (security, device detection)
-│   ├── tests/              # 97% coverage, 743 tests
+│   ├── tests/              # 96% coverage, 987 tests
 │   └── alembic/            # Database migrations
 │
-└── frontend/               # Next.js 15 frontend
+└── frontend/               # Next.js 16 frontend
     ├── src/
-    │   ├── app/           # App Router pages (Next.js 15)
+    │   ├── app/           # App Router pages (Next.js 16)
     │   ├── components/    # React components
     │   ├── lib/
     │   │   ├── api/       # Auto-generated API client
@@ -60,6 +60,7 @@ Default superuser (change in production):
 
 ### 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`
@@ -68,10 +69,51 @@ Default superuser (change in production):
   - `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
-- **CRUD base class**: `crud/base.py` with common operations
+- **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
@@ -79,7 +121,7 @@ Default superuser (change in production):
 ### Frontend State Management
 - **Zustand stores**: Lightweight state management
 - **TanStack Query**: API data fetching/caching
-- **Auto-generated client**: From OpenAPI spec via `npm run generate:api`
+- **Auto-generated client**: From OpenAPI spec via `bun run generate:api`
 - **Dependency Injection**: ALWAYS use `useAuth()` from `AuthContext`, NEVER import `useAuthStore` directly
 
 ### Internationalization (i18n)
@@ -105,35 +147,47 @@ Permission dependencies in `api/dependencies/permissions.py`:
 
 ### Testing Infrastructure
 
-**Backend (pytest):**
-- 97% coverage, 743 tests
+**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`
-- Coverage: `IS_TEST=True uv run pytest --cov=app --cov-report=term-missing`
+- 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: `npm test`
-- Coverage: `npm run test:coverage`
+- Run: `bun run test`
+- Coverage: `bun run test:coverage`
 
-**E2E Tests (Playwright):**
+**Frontend E2E Tests (Playwright):**
 - 56 passing, 1 skipped (zero flaky tests)
 - Complete user flows (auth, navigation, settings)
-- Run: `npm run test:e2e`
-- UI mode: `npm run test:e2e:ui`
+- 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)
-- **mypy**: Type checking with Pydantic plugin
+- **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 15**: App Router with React 19
+- **Next.js 16**: App Router with React 19
 - **TypeScript**: Full type safety
 - **TailwindCSS + shadcn/ui**: Design system
 - **ESLint + Prettier**: Code quality
@@ -168,11 +222,11 @@ NEXT_PUBLIC_API_URL=http://localhost:8000/api/v1
 ### Adding a New API Endpoint
 
 1. **Define schema** in `backend/app/schemas/`
-2. **Create CRUD operations** in `backend/app/crud/`
+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**: `npm run generate:api`
+6. **Generate frontend client**: `bun run generate:api`
 
 ### Database Migrations
 
@@ -189,7 +243,7 @@ python migrate.py auto "description"      # Generate + apply
 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**: `npm run type-check`
+5. **Run type check**: `bun run type-check`
 
 ## Security Features
 
@@ -199,6 +253,10 @@ python migrate.py auto "description"      # Generate + apply
 - **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
 
@@ -228,13 +286,14 @@ docker-compose exec backend python -c "from app.init_db import init_db; import a
 ## Current Status (Nov 2025)
 
 ### Completed Features ✅
-- Authentication system (JWT with refresh tokens)
+- 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 (CRUD, password change)
+- 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 (97% backend, 97% frontend unit, 56 E2E tests)
+- 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
@@ -249,7 +308,7 @@ docker-compose exec backend python -c "from app.init_db import init_db; import a
 ### Planned 🔮
 - GitHub Actions CI/CD
 - Additional languages (Spanish, French, German, etc.)
-- Additional authentication methods (OAuth, SSO)
+- SSO/SAML authentication
 - Real-time notifications (WebSockets)
 - Webhook system
 - Background job processing

CLAUDE.md

@@ -43,17 +43,33 @@ EOF
 - Check current state: `python migrate.py current`
 
 **Frontend API Client Generation:**
-- Run `npm run generate:api` after backend schema changes
+- 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
 
 **Testing Commands:**
-- Backend: `IS_TEST=True uv run pytest` (always prefix with `IS_TEST=True`)
-- Frontend unit: `npm test`
-- Frontend E2E: `npm run test:e2e`
+- 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
 
+**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
+
+**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
 
 **ALWAYS use `useAuth()` from `AuthContext`, NEVER import `useAuthStore` directly!**
@@ -78,8 +94,6 @@ 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
 
 When writing or fixing Playwright tests:
@@ -134,7 +148,7 @@ async def mock_commit():
 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()
 ```
 
@@ -149,14 +163,18 @@ with patch.object(session, 'commit', side_effect=mock_commit):
 - 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 CRUD
+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: `npm run generate:api`
+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
@@ -169,10 +187,24 @@ with patch.object(session, 'commit', side_effect=mock_commit):
 
 **When Debugging:**
 - Backend: Check `IS_TEST=True` environment variable is set
-- Frontend: Run `npm run type-check` first
-- E2E: Use `npm run test:e2e:debug` for step-by-step debugging
+- 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:**
@@ -192,7 +224,7 @@ with patch.object(session, 'commit', side_effect=mock_commit):
 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 → CRUD → route → tests → frontend client)
+- 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
@@ -205,7 +237,6 @@ No Claude Code Skills installed yet. To create one, invoke the built-in "skill-c
 - [README.md](./README.md) - User-facing project overview
 - `backend/docs/` - Backend architecture, coding standards, common pitfalls
 - `frontend/docs/design-system/` - Complete design system guide
-- `frontend/docs/ARCHITECTURE_FIX_REPORT.md` - Critical DI pattern fixes
 
 **API Documentation (when running):**
 - Swagger UI: http://localhost:8000/docs

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

@@ -1,8 +1,40 @@
-.PHONY: dev dev-full 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:
 	# Bring up all dev services except the frontend
@@ -16,25 +48,77 @@ dev-full:
 	# Bring up all dev services including the frontend (full stack)
 	docker compose -f docker-compose.dev.yml up --build -d
 
-prod:
-	docker compose 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

@@ -1,30 +1,14 @@
-# PragmaStack
+# <img src="frontend/public/logo.svg" alt="PragmaStack" width="32" height="32" style="vertical-align: middle" /> PragmaStack
 
 > **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)
 
----
-
-## 🤖 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.
+![Landing Page](docs/images/landing.png)
 
 ---
 
@@ -47,12 +31,26 @@ Whether you're building a SaaS, an internal tool, or a side project, PragmaStack
 
 ### 🔐 **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
@@ -60,14 +58,14 @@ Whether you're building a SaaS, an internal tool, or a side project, PragmaStack
 - 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
+- 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)
@@ -129,6 +127,65 @@ Whether you're building a SaaS, an internal tool, or a side project, PragmaStack
 
 ---
 
+## 📸 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)**
+
+---
+
 ## 🚀 Tech Stack
 
 ### Backend
@@ -140,7 +197,7 @@ Whether you're building a SaaS, an internal tool, or a side project, PragmaStack
 - **[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
@@ -177,12 +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
@@ -242,17 +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!
@@ -266,7 +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
@@ -321,7 +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
@@ -334,13 +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:**
@@ -358,10 +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
@@ -380,6 +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:
@@ -426,7 +493,6 @@ python migrate.py current
   - 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
@@ -475,8 +541,8 @@ 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)
@@ -502,8 +568,9 @@ docker-compose down
 - [ ] GitHub Actions CI/CD pipelines
 - [ ] Dynamic test coverage badges from CI
 - [ ] E2E test coverage reporting
+- [ ] OAuth token encryption at rest (security hardening)
 - [ ] Additional languages (Spanish, French, German, etc.)
-- [ ] Additional authentication methods (OAuth, SSO)
+- [ ] SSO/SAML authentication
 - [ ] Real-time notifications with WebSockets
 - [ ] Webhook system
 - [ ] File upload/storage (S3-compatible)
@@ -540,7 +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
@@ -574,8 +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

@@ -1,9 +1,6 @@
 # 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 \
@@ -31,19 +28,16 @@ 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 \
@@ -54,18 +48,18 @@ ENV PYTHONDONTWRITEBYTECODE=1 \
     UV_NO_CACHE=1
 
 # Install system dependencies and uv
-RUN apt-get update && \
-    apt-get install -y --no-install-recommends postgresql-client curl ca-certificates && \
+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/ && \
-    apt-get clean && \
-    rm -rf /var/lib/apt/lists/*
+    mv /root/.local/bin/uv* /usr/local/bin/
 
 # Copy dependency files
 COPY pyproject.toml uv.lock ./
 
-# Install only production dependencies using uv (no dev dependencies)
-RUN uv sync --frozen --no-dev
+# 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 . .

backend/Makefile

@@ -1,4 +1,7 @@
-.PHONY: help lint lint-fix format format-check type-check test test-cov validate clean install-dev sync
+.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:
@@ -6,6 +9,7 @@ help:
 	@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:"
@@ -13,12 +17,30 @@ help:
 	@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 mypy type checking"
-	@echo "  make validate      - Run all checks (lint + format + types)"
+	@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"
+	@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"
@@ -58,12 +80,52 @@ format-check:
 	@uv run ruff format --check app/ tests/
 
 type-check:
-	@echo "🔎 Running mypy type checking..."
-	@uv run mypy app/
+	@echo "🔎 Running pyright type checking..."
+	@uv run pyright app/
 
-validate: lint format-check type-check
+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
 # ============================================================================
@@ -77,6 +139,68 @@ test-cov:
 	@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
 # ============================================================================
@@ -85,7 +209,7 @@ 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 ".mypy_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

backend/README.md

@@ -14,7 +14,9 @@ Features:
 - **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, mypy for type checking
+- **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
 
@@ -149,7 +151,7 @@ uv pip list --outdated
 # Run any Python command via uv (no activation needed)
 uv run python script.py
 uv run pytest
-uv run mypy app/
+uv run pyright app/
 
 # Or activate the virtual environment
 source .venv/bin/activate
@@ -171,12 +173,22 @@ 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 mypy type checking
+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
@@ -252,7 +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
@@ -352,18 +364,29 @@ open htmlcov/index.html
 # Using Makefile (recommended)
 make lint          # Ruff linting
 make format        # Ruff formatting
-make type-check    # mypy type checking
+make type-check    # Pyright type checking
 make validate      # All checks at once
 
+# 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
+
 # Using uv directly
 uv run ruff check app/ tests/
 uv run ruff format app/ tests/
-uv run mypy app/
+uv run pyright app/
 ```
 
 **Tools:**
 - **Ruff**: All-in-one linting, formatting, and import sorting (replaces Black, Flake8, isort)
-- **mypy**: Static type checking with Pydantic plugin
+- **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`.
 
@@ -439,7 +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/`
@@ -589,13 +612,42 @@ 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 (`uv sync --upgrade`)
+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
 
 ---
 
@@ -645,7 +697,11 @@ logging.basicConfig(level=logging.INFO)
 **Built with modern Python tooling:**
 - 🚀 **uv** - 10-100x faster dependency management
 - ⚡ **Ruff** - 10-100x faster linting & formatting
-- 🔍 **mypy** - Static type checking
+- 🔍 **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

@@ -22,6 +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:
@@ -100,6 +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 +144,12 @@ def run_migrations_online() -> None:
     )
 
     with connectable.connect() as connection:
-        context.configure(connection=connection, target_metadata=target_metadata)
+        context.configure(
+            connection=connection,
+            target_metadata=target_metadata,
+            compare_type=True,
+            include_object=include_object,
+        )
 
         with context.begin_transaction():
             context.run_migrations()

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 collections.abc import Sequence
-
-import sqlalchemy as sa
-from alembic import op
-
-# revision identifiers, used by Alembic.
-revision: str = "1174fffbe3e4"
-down_revision: str | None = "fbf6318a8a36"
-branch_labels: str | Sequence[str] | None = None
-depends_on: 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

@@ -1,36 +0,0 @@
-"""add_soft_delete_to_users
-
-Revision ID: 2d0fcec3b06d
-Revises: 9e4f2a1b8c7d
-Create Date: 2025-10-30 16:40:21.000021
-
-"""
-
-from collections.abc import Sequence
-
-import sqlalchemy as sa
-from alembic import op
-
-# revision identifiers, used by Alembic.
-revision: str = "2d0fcec3b06d"
-down_revision: str | None = "9e4f2a1b8c7d"
-branch_labels: str | Sequence[str] | None = None
-depends_on: 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 collections.abc import Sequence
-
-import sqlalchemy as sa
-from alembic import op
-
-# revision identifiers, used by Alembic.
-revision: str = "38bf9e7e74b3"
-down_revision: str | None = "7396957cbe80"
-branch_labels: str | Sequence[str] | None = None
-depends_on: 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

@@ -1,89 +0,0 @@
-"""add_user_sessions_table
-
-Revision ID: 549b50ea888d
-Revises: b76c725fc3cf
-Create Date: 2025-10-31 07:41:18.729544
-
-"""
-
-from collections.abc import Sequence
-
-import sqlalchemy as sa
-from alembic import op
-
-# revision identifiers, used by Alembic.
-revision: str = "549b50ea888d"
-down_revision: str | None = "b76c725fc3cf"
-branch_labels: str | Sequence[str] | None = None
-depends_on: 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

@@ -1,23 +0,0 @@
-"""Initial empty migration
-
-Revision ID: 7396957cbe80
-Revises:
-Create Date: 2025-02-27 12:47:46.445313
-
-"""
-
-from collections.abc import Sequence
-
-# revision identifiers, used by Alembic.
-revision: str = "7396957cbe80"
-down_revision: str | None = None
-branch_labels: str | Sequence[str] | None = None
-depends_on: 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

@@ -1,116 +0,0 @@
-"""Add missing indexes and fix column types
-
-Revision ID: 9e4f2a1b8c7d
-Revises: 38bf9e7e74b3
-Create Date: 2025-10-30 10:00:00.000000
-
-"""
-
-from collections.abc import Sequence
-
-import sqlalchemy as sa
-from alembic import op
-
-# revision identifiers, used by Alembic.
-revision: str = "9e4f2a1b8c7d"
-down_revision: str | None = "38bf9e7e74b3"
-branch_labels: str | Sequence[str] | None = None
-depends_on: 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

@@ -1,48 +0,0 @@
-"""add_composite_indexes
-
-Revision ID: b76c725fc3cf
-Revises: 2d0fcec3b06d
-Create Date: 2025-10-30 16:41:33.273135
-
-"""
-
-from collections.abc import Sequence
-
-import sqlalchemy as sa
-from alembic import op
-
-# revision identifiers, used by Alembic.
-revision: str = "b76c725fc3cf"
-down_revision: str | None = "2d0fcec3b06d"
-branch_labels: str | Sequence[str] | None = None
-depends_on: 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/c8e9f3a2d1b4_add_user_locale_preference_column.py

@@ -1,39 +0,0 @@
-"""add user locale preference column
-
-Revision ID: c8e9f3a2d1b4
-Revises: b76c725fc3cf
-Create Date: 2025-11-17 18:00:00.000000
-
-"""
-
-from collections.abc import Sequence
-
-import sqlalchemy as sa
-from alembic import op
-
-# revision identifiers, used by Alembic.
-revision: str = "c8e9f3a2d1b4"
-down_revision: str | None = "b76c725fc3cf"
-branch_labels: str | Sequence[str] | None = None
-depends_on: str | Sequence[str] | None = None
-
-
-def upgrade() -> None:
-    # Add locale column to users table
-    # VARCHAR(10) supports BCP 47 format (e.g., "en", "it", "en-US", "it-IT")
-    # Nullable: NULL means "not set yet", will use Accept-Language header fallback
-    # Indexed: For analytics queries and filtering by locale
-    op.add_column("users", sa.Column("locale", sa.String(length=10), nullable=True))
-
-    # Create index on locale column for performance
-    op.create_index(
-        "ix_users_locale",
-        "users",
-        ["locale"],
-    )
-
-
-def downgrade() -> None:
-    # Remove locale index and column
-    op.drop_index("ix_users_locale", table_name="users")
-    op.drop_column("users", "locale")

backend/app/alembic/versions/fbf6318a8a36_add_organizations_and_user_organizations.py

@@ -1,127 +0,0 @@
-"""add_organizations_and_user_organizations
-
-Revision ID: fbf6318a8a36
-Revises: 549b50ea888d
-Create Date: 2025-10-31 12:08:05.141353
-
-"""
-
-from collections.abc import Sequence
-
-import sqlalchemy as sa
-from alembic import op
-
-# revision identifiers, used by Alembic.
-revision: str = "fbf6318a8a36"
-down_revision: str | None = "549b50ea888d"
-branch_labels: str | Sequence[str] | None = None
-depends_on: 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

@@ -1,12 +1,12 @@
 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 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")
@@ -32,9 +32,8 @@ 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(
@@ -144,8 +143,7 @@ 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

backend/app/api/dependencies/permissions.py

@@ -15,9 +15,9 @@ 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:
@@ -81,7 +81,7 @@ class OrganizationPermission:
             return current_user
 
         # Get user's role in organization
-        user_role = await organization_crud.get_user_role_in_org(
+        user_role = await organization_service.get_user_role_in_org(
             db, user_id=current_user.id, organization_id=organization_id
         )
 
@@ -123,7 +123,7 @@ async def require_org_membership(
     if current_user.is_superuser:
         return current_user
 
-    user_role = await organization_crud.get_user_role_in_org(
+    user_role = await organization_service.get_user_role_in_org(
         db, user_id=current_user.id, organization_id=organization_id
     )
 

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

@@ -1,9 +1,21 @@
 from fastapi import APIRouter
 
-from app.api.routes import admin, auth, organizations, sessions, users
+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"])

backend/app/api/routes/admin.py

@@ -7,6 +7,7 @@ for managing the application.
 """
 
 import logging
+from datetime import UTC, datetime, timedelta
 from enum import Enum
 from typing import Any
 from uuid import UUID
@@ -23,9 +24,7 @@ from app.core.exceptions import (
     ErrorCode,
     NotFoundError,
 )
-from app.crud.organization import organization as organization_crud
-from app.crud.session import session as session_crud
-from app.crud.user import user as user_crud
+from app.core.repository_exceptions import DuplicateEntryError
 from app.models.user import User
 from app.models.user_organization import OrganizationRole
 from app.schemas.common import (
@@ -43,6 +42,9 @@ from app.schemas.organizations import (
 )
 from app.schemas.sessions import AdminSessionResponse
 from app.schemas.users import UserCreate, UserResponse, UserUpdate
+from app.services.organization_service import organization_service
+from app.services.session_service import session_service
+from app.services.user_service import user_service
 
 logger = logging.getLogger(__name__)
 
@@ -63,7 +65,7 @@ class BulkUserAction(BaseModel):
 
     action: BulkAction = Field(..., description="Action to perform on selected users")
     user_ids: list[UUID] = Field(
-        ..., min_items=1, max_items=100, description="List of user IDs (max 100)"
+        ..., min_length=1, max_length=100, description="List of user IDs (max 100)"
     )
 
 
@@ -80,6 +82,186 @@ class BulkActionResult(BaseModel):
 # ===== User Management Endpoints =====
 
 
+class UserGrowthData(BaseModel):
+    date: str
+    total_users: int
+    active_users: int
+
+
+class OrgDistributionData(BaseModel):
+    name: str
+    value: int
+
+
+class RegistrationActivityData(BaseModel):
+    date: str
+    registrations: int
+
+
+class UserStatusData(BaseModel):
+    name: str
+    value: int
+
+
+class AdminStatsResponse(BaseModel):
+    user_growth: list[UserGrowthData]
+    organization_distribution: list[OrgDistributionData]
+    registration_activity: list[RegistrationActivityData]
+    user_status: list[UserStatusData]
+
+
+def _generate_demo_stats() -> AdminStatsResponse:  # pragma: no cover
+    """Generate demo statistics for empty databases."""
+    from random import randint
+
+    # Demo user growth (last 30 days)
+    user_growth = []
+    total = 10
+    for i in range(29, -1, -1):
+        date = datetime.now(UTC) - timedelta(days=i)
+        total += randint(0, 3)  # noqa: S311
+        user_growth.append(
+            UserGrowthData(
+                date=date.strftime("%b %d"),
+                total_users=total,
+                active_users=int(total * 0.85),
+            )
+        )
+
+    # Demo organization distribution
+    org_dist = [
+        OrgDistributionData(name="Engineering", value=12),
+        OrgDistributionData(name="Product", value=8),
+        OrgDistributionData(name="Sales", value=15),
+        OrgDistributionData(name="Marketing", value=6),
+        OrgDistributionData(name="Support", value=5),
+        OrgDistributionData(name="Operations", value=4),
+    ]
+
+    # Demo registration activity (last 14 days)
+    registration_activity = []
+    for i in range(13, -1, -1):
+        date = datetime.now(UTC) - timedelta(days=i)
+        registration_activity.append(
+            RegistrationActivityData(
+                date=date.strftime("%b %d"),
+                registrations=randint(0, 5),  # noqa: S311
+            )
+        )
+
+    # Demo user status
+    user_status = [
+        UserStatusData(name="Active", value=45),
+        UserStatusData(name="Inactive", value=5),
+    ]
+
+    return AdminStatsResponse(
+        user_growth=user_growth,
+        organization_distribution=org_dist,
+        registration_activity=registration_activity,
+        user_status=user_status,
+    )
+
+
+@router.get(
+    "/stats",
+    response_model=AdminStatsResponse,
+    summary="Admin: Get Dashboard Stats",
+    description="Get aggregated statistics for the admin dashboard (admin only)",
+    operation_id="admin_get_stats",
+)
+async def admin_get_stats(
+    admin: User = Depends(require_superuser),
+    db: AsyncSession = Depends(get_db),
+) -> Any:
+    """Get admin dashboard statistics with real data from database."""
+    from app.core.config import settings
+
+    stats = await user_service.get_stats(db)
+    total_users = stats["total_users"]
+    active_count = stats["active_count"]
+    inactive_count = stats["inactive_count"]
+    all_users = stats["all_users"]
+
+    # If database is essentially empty (only admin user), return demo data
+    if total_users <= 1 and settings.DEMO_MODE:  # pragma: no cover
+        logger.info("Returning demo stats data (empty database in demo mode)")
+        return _generate_demo_stats()
+
+    # 1. User Growth (Last 30 days)
+    user_growth = []
+    for i in range(29, -1, -1):
+        date = datetime.now(UTC) - timedelta(days=i)
+        date_start = date.replace(hour=0, minute=0, second=0, microsecond=0, tzinfo=UTC)
+        date_end = date_start + timedelta(days=1)
+
+        total_users_on_date = sum(
+            1
+            for u in all_users
+            if u.created_at and u.created_at.replace(tzinfo=UTC) < date_end
+        )
+        active_users_on_date = sum(
+            1
+            for u in all_users
+            if u.created_at
+            and u.created_at.replace(tzinfo=UTC) < date_end
+            and u.is_active
+        )
+
+        user_growth.append(
+            UserGrowthData(
+                date=date.strftime("%b %d"),
+                total_users=total_users_on_date,
+                active_users=active_users_on_date,
+            )
+        )
+
+    # 2. Organization Distribution - Top 6 organizations by member count
+    org_rows = await organization_service.get_org_distribution(db, limit=6)
+    org_dist = [OrgDistributionData(name=r["name"], value=r["value"]) for r in org_rows]
+
+    # 3. User Registration Activity (Last 14 days)
+    registration_activity = []
+    for i in range(13, -1, -1):
+        date = datetime.now(UTC) - timedelta(days=i)
+        date_start = date.replace(hour=0, minute=0, second=0, microsecond=0, tzinfo=UTC)
+        date_end = date_start + timedelta(days=1)
+
+        day_registrations = sum(
+            1
+            for u in all_users
+            if u.created_at
+            and date_start <= u.created_at.replace(tzinfo=UTC) < date_end
+        )
+
+        registration_activity.append(
+            RegistrationActivityData(
+                date=date.strftime("%b %d"),
+                registrations=day_registrations,
+            )
+        )
+
+    # 4. User Status - Active vs Inactive
+    logger.info(
+        "User status counts - Active: %s, Inactive: %s", active_count, inactive_count
+    )
+
+    user_status = [
+        UserStatusData(name="Active", value=active_count),
+        UserStatusData(name="Inactive", value=inactive_count),
+    ]
+
+    return AdminStatsResponse(
+        user_growth=user_growth,
+        organization_distribution=org_dist,
+        registration_activity=registration_activity,
+        user_status=user_status,
+    )
+
+
+# ===== User Management Endpoints =====
+
+
 @router.get(
     "/users",
     response_model=PaginatedResponse[UserResponse],
@@ -110,7 +292,7 @@ async def admin_list_users(
             filters["is_superuser"] = is_superuser
 
         # Get users with search
-        users, total = await user_crud.get_multi_with_total(
+        users, total = await user_service.list_users(
             db,
             skip=pagination.offset,
             limit=pagination.limit,
@@ -130,7 +312,7 @@ async def admin_list_users(
         return PaginatedResponse(data=users, pagination=pagination_meta)
 
     except Exception as e:
-        logger.error(f"Error listing users (admin): {e!s}", exc_info=True)
+        logger.exception("Error listing users (admin): %s", e)
         raise
 
 
@@ -153,14 +335,14 @@ async def admin_create_user(
     Allows setting is_superuser and other fields.
     """
     try:
-        user = await user_crud.create(db, obj_in=user_in)
-        logger.info(f"Admin {admin.email} created user {user.email}")
+        user = await user_service.create_user(db, user_in)
+        logger.info("Admin %s created user %s", admin.email, user.email)
         return user
-    except ValueError as e:
-        logger.warning(f"Failed to create user: {e!s}")
-        raise NotFoundError(message=str(e), error_code=ErrorCode.USER_ALREADY_EXISTS)
+    except DuplicateEntryError as e:
+        logger.warning("Failed to create user: %s", e)
+        raise DuplicateError(message=str(e), error_code=ErrorCode.USER_ALREADY_EXISTS)
     except Exception as e:
-        logger.error(f"Error creating user (admin): {e!s}", exc_info=True)
+        logger.exception("Error creating user (admin): %s", e)
         raise
 
 
@@ -177,11 +359,7 @@ async def admin_get_user(
     db: AsyncSession = Depends(get_db),
 ) -> Any:
     """Get detailed information about a specific user."""
-    user = await user_crud.get(db, id=user_id)
-    if not user:
-        raise NotFoundError(
-            message=f"User {user_id} not found", error_code=ErrorCode.USER_NOT_FOUND
-        )
+    user = await user_service.get_user(db, str(user_id))
     return user
 
 
@@ -200,20 +378,13 @@ async def admin_update_user(
 ) -> Any:
     """Update user information with admin privileges."""
     try:
-        user = await user_crud.get(db, id=user_id)
-        if not user:
-            raise NotFoundError(
-                message=f"User {user_id} not found", error_code=ErrorCode.USER_NOT_FOUND
-            )
-
-        updated_user = await user_crud.update(db, db_obj=user, obj_in=user_in)
-        logger.info(f"Admin {admin.email} updated user {updated_user.email}")
+        user = await user_service.get_user(db, str(user_id))
+        updated_user = await user_service.update_user(db, user=user, obj_in=user_in)
+        logger.info("Admin %s updated user %s", admin.email, updated_user.email)
         return updated_user
 
-    except NotFoundError:
-        raise
     except Exception as e:
-        logger.error(f"Error updating user (admin): {e!s}", exc_info=True)
+        logger.exception("Error updating user (admin): %s", e)
         raise
 
 
@@ -231,11 +402,7 @@ async def admin_delete_user(
 ) -> Any:
     """Soft delete a user (sets deleted_at timestamp)."""
     try:
-        user = await user_crud.get(db, id=user_id)
-        if not user:
-            raise NotFoundError(
-                message=f"User {user_id} not found", error_code=ErrorCode.USER_NOT_FOUND
-            )
+        user = await user_service.get_user(db, str(user_id))
 
         # Prevent deleting yourself
         if user.id == admin.id:
@@ -245,17 +412,15 @@ async def admin_delete_user(
                 error_code=ErrorCode.OPERATION_FORBIDDEN,
             )
 
-        await user_crud.soft_delete(db, id=user_id)
-        logger.info(f"Admin {admin.email} deleted user {user.email}")
+        await user_service.soft_delete_user(db, str(user_id))
+        logger.info("Admin %s deleted user %s", admin.email, user.email)
 
         return MessageResponse(
             success=True, message=f"User {user.email} has been deleted"
         )
 
-    except NotFoundError:
-        raise
     except Exception as e:
-        logger.error(f"Error deleting user (admin): {e!s}", exc_info=True)
+        logger.exception("Error deleting user (admin): %s", e)
         raise
 
 
@@ -273,23 +438,16 @@ async def admin_activate_user(
 ) -> Any:
     """Activate a user account."""
     try:
-        user = await user_crud.get(db, id=user_id)
-        if not user:
-            raise NotFoundError(
-                message=f"User {user_id} not found", error_code=ErrorCode.USER_NOT_FOUND
-            )
-
-        await user_crud.update(db, db_obj=user, obj_in={"is_active": True})
-        logger.info(f"Admin {admin.email} activated user {user.email}")
+        user = await user_service.get_user(db, str(user_id))
+        await user_service.update_user(db, user=user, obj_in={"is_active": True})
+        logger.info("Admin %s activated user %s", admin.email, user.email)
 
         return MessageResponse(
             success=True, message=f"User {user.email} has been activated"
         )
 
-    except NotFoundError:
-        raise
     except Exception as e:
-        logger.error(f"Error activating user (admin): {e!s}", exc_info=True)
+        logger.exception("Error activating user (admin): %s", e)
         raise
 
 
@@ -307,11 +465,7 @@ async def admin_deactivate_user(
 ) -> Any:
     """Deactivate a user account."""
     try:
-        user = await user_crud.get(db, id=user_id)
-        if not user:
-            raise NotFoundError(
-                message=f"User {user_id} not found", error_code=ErrorCode.USER_NOT_FOUND
-            )
+        user = await user_service.get_user(db, str(user_id))
 
         # Prevent deactivating yourself
         if user.id == admin.id:
@@ -321,17 +475,15 @@ async def admin_deactivate_user(
                 error_code=ErrorCode.OPERATION_FORBIDDEN,
             )
 
-        await user_crud.update(db, db_obj=user, obj_in={"is_active": False})
-        logger.info(f"Admin {admin.email} deactivated user {user.email}")
+        await user_service.update_user(db, user=user, obj_in={"is_active": False})
+        logger.info("Admin %s deactivated user %s", admin.email, user.email)
 
         return MessageResponse(
             success=True, message=f"User {user.email} has been deactivated"
         )
 
-    except NotFoundError:
-        raise
     except Exception as e:
-        logger.error(f"Error deactivating user (admin): {e!s}", exc_info=True)
+        logger.exception("Error deactivating user (admin): %s", e)
         raise
 
 
@@ -356,19 +508,19 @@ async def admin_bulk_user_action(
     try:
         # Use efficient bulk operations instead of loop
         if bulk_action.action == BulkAction.ACTIVATE:
-            affected_count = await user_crud.bulk_update_status(
+            affected_count = await user_service.bulk_update_status(
                 db, user_ids=bulk_action.user_ids, is_active=True
             )
         elif bulk_action.action == BulkAction.DEACTIVATE:
-            affected_count = await user_crud.bulk_update_status(
+            affected_count = await user_service.bulk_update_status(
                 db, user_ids=bulk_action.user_ids, is_active=False
             )
         elif bulk_action.action == BulkAction.DELETE:
             # bulk_soft_delete automatically excludes the admin user
-            affected_count = await user_crud.bulk_soft_delete(
+            affected_count = await user_service.bulk_soft_delete(
                 db, user_ids=bulk_action.user_ids, exclude_user_id=admin.id
             )
-        else:
+        else:  # pragma: no cover
             raise ValueError(f"Unsupported bulk action: {bulk_action.action}")
 
         # Calculate failed count (requested - affected)
@@ -376,8 +528,11 @@ async def admin_bulk_user_action(
         failed_count = requested_count - affected_count
 
         logger.info(
-            f"Admin {admin.email} performed bulk {bulk_action.action.value} "
-            f"on {affected_count} users ({failed_count} skipped/failed)"
+            "Admin %s performed bulk %s on %s users (%s skipped/failed)",
+            admin.email,
+            bulk_action.action.value,
+            affected_count,
+            failed_count,
         )
 
         return BulkActionResult(
@@ -388,8 +543,8 @@ async def admin_bulk_user_action(
             failed_ids=None,  # Bulk operations don't track individual failures
         )
 
-    except Exception as e:
-        logger.error(f"Error in bulk user action: {e!s}", exc_info=True)
+    except Exception as e:  # pragma: no cover
+        logger.exception("Error in bulk user action: %s", e)
         raise
 
 
@@ -413,7 +568,7 @@ async def admin_list_organizations(
     """List all organizations with filtering and search."""
     try:
         # Use optimized method that gets member counts in single query (no N+1)
-        orgs_with_data, total = await organization_crud.get_multi_with_member_counts(
+        orgs_with_data, total = await organization_service.get_multi_with_member_counts(
             db,
             skip=pagination.offset,
             limit=pagination.limit,
@@ -450,7 +605,7 @@ async def admin_list_organizations(
         return PaginatedResponse(data=orgs_with_count, pagination=pagination_meta)
 
     except Exception as e:
-        logger.error(f"Error listing organizations (admin): {e!s}", exc_info=True)
+        logger.exception("Error listing organizations (admin): %s", e)
         raise
 
 
@@ -469,8 +624,8 @@ async def admin_create_organization(
 ) -> Any:
     """Create a new organization."""
     try:
-        org = await organization_crud.create(db, obj_in=org_in)
-        logger.info(f"Admin {admin.email} created organization {org.name}")
+        org = await organization_service.create_organization(db, obj_in=org_in)
+        logger.info("Admin %s created organization %s", admin.email, org.name)
 
         # Add member count
         org_dict = {
@@ -486,11 +641,11 @@ async def admin_create_organization(
         }
         return OrganizationResponse(**org_dict)
 
-    except ValueError as e:
-        logger.warning(f"Failed to create organization: {e!s}")
-        raise NotFoundError(message=str(e), error_code=ErrorCode.ALREADY_EXISTS)
+    except DuplicateEntryError as e:
+        logger.warning("Failed to create organization: %s", e)
+        raise DuplicateError(message=str(e), error_code=ErrorCode.ALREADY_EXISTS)
     except Exception as e:
-        logger.error(f"Error creating organization (admin): {e!s}", exc_info=True)
+        logger.exception("Error creating organization (admin): %s", e)
         raise
 
 
@@ -507,12 +662,7 @@ async def admin_get_organization(
     db: AsyncSession = Depends(get_db),
 ) -> Any:
     """Get detailed information about a specific organization."""
-    org = await organization_crud.get(db, id=org_id)
-    if not org:
-        raise NotFoundError(
-            message=f"Organization {org_id} not found", error_code=ErrorCode.NOT_FOUND
-        )
-
+    org = await organization_service.get_organization(db, str(org_id))
     org_dict = {
         "id": org.id,
         "name": org.name,
@@ -522,7 +672,7 @@ async def admin_get_organization(
         "settings": org.settings,
         "created_at": org.created_at,
         "updated_at": org.updated_at,
-        "member_count": await organization_crud.get_member_count(
+        "member_count": await organization_service.get_member_count(
             db, organization_id=org.id
         ),
     }
@@ -544,15 +694,11 @@ async def admin_update_organization(
 ) -> Any:
     """Update organization information."""
     try:
-        org = await organization_crud.get(db, id=org_id)
-        if not org:
-            raise NotFoundError(
-                message=f"Organization {org_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"Admin {admin.email} updated organization {updated_org.name}")
+        org = await organization_service.get_organization(db, str(org_id))
+        updated_org = await organization_service.update_organization(
+            db, org=org, obj_in=org_in
+        )
+        logger.info("Admin %s updated organization %s", admin.email, updated_org.name)
 
         org_dict = {
             "id": updated_org.id,
@@ -563,16 +709,14 @@ async def admin_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(
+            "member_count": await organization_service.get_member_count(
                 db, organization_id=updated_org.id
             ),
         }
         return OrganizationResponse(**org_dict)
 
-    except NotFoundError:
-        raise
     except Exception as e:
-        logger.error(f"Error updating organization (admin): {e!s}", exc_info=True)
+        logger.exception("Error updating organization (admin): %s", e)
         raise
 
 
@@ -590,24 +734,16 @@ async def admin_delete_organization(
 ) -> Any:
     """Delete an organization and all its relationships."""
     try:
-        org = await organization_crud.get(db, id=org_id)
-        if not org:
-            raise NotFoundError(
-                message=f"Organization {org_id} not found",
-                error_code=ErrorCode.NOT_FOUND,
-            )
-
-        await organization_crud.remove(db, id=org_id)
-        logger.info(f"Admin {admin.email} deleted organization {org.name}")
+        org = await organization_service.get_organization(db, str(org_id))
+        await organization_service.remove_organization(db, str(org_id))
+        logger.info("Admin %s deleted organization %s", admin.email, org.name)
 
         return MessageResponse(
             success=True, message=f"Organization {org.name} has been deleted"
         )
 
-    except NotFoundError:
-        raise
     except Exception as e:
-        logger.error(f"Error deleting organization (admin): {e!s}", exc_info=True)
+        logger.exception("Error deleting organization (admin): %s", e)
         raise
 
 
@@ -627,14 +763,8 @@ async def admin_list_organization_members(
 ) -> Any:
     """List all members of an organization."""
     try:
-        org = await organization_crud.get(db, id=org_id)
-        if not org:
-            raise NotFoundError(
-                message=f"Organization {org_id} not found",
-                error_code=ErrorCode.NOT_FOUND,
-            )
-
-        members, total = await organization_crud.get_organization_members(
+        await organization_service.get_organization(db, str(org_id))  # validates exists
+        members, total = await organization_service.get_organization_members(
             db,
             organization_id=org_id,
             skip=pagination.offset,
@@ -657,9 +787,7 @@ async def admin_list_organization_members(
     except NotFoundError:
         raise
     except Exception as e:
-        logger.error(
-            f"Error listing organization members (admin): {e!s}", exc_info=True
-        )
+        logger.exception("Error listing organization members (admin): %s", e)
         raise
 
 
@@ -687,45 +815,32 @@ async def admin_add_organization_member(
 ) -> Any:
     """Add a user to an organization."""
     try:
-        org = await organization_crud.get(db, id=org_id)
-        if not org:
-            raise NotFoundError(
-                message=f"Organization {org_id} not found",
-                error_code=ErrorCode.NOT_FOUND,
-            )
+        org = await organization_service.get_organization(db, str(org_id))
+        user = await user_service.get_user(db, str(request.user_id))
 
-        user = await user_crud.get(db, id=request.user_id)
-        if not user:
-            raise NotFoundError(
-                message=f"User {request.user_id} not found",
-                error_code=ErrorCode.USER_NOT_FOUND,
-            )
-
-        await organization_crud.add_user(
+        await organization_service.add_member(
             db, organization_id=org_id, user_id=request.user_id, role=request.role
         )
 
         logger.info(
-            f"Admin {admin.email} added user {user.email} to organization {org.name} "
-            f"with role {request.role.value}"
+            "Admin %s added user %s to organization %s with role %s",
+            admin.email,
+            user.email,
+            org.name,
+            request.role.value,
         )
 
         return MessageResponse(
             success=True, message=f"User {user.email} added to organization {org.name}"
         )
 
-    except ValueError as e:
-        logger.warning(f"Failed to add user to organization: {e!s}")
-        # Use DuplicateError for "already exists" scenarios
+    except DuplicateEntryError as e:
+        logger.warning("Failed to add user to organization: %s", e)
         raise DuplicateError(
             message=str(e), error_code=ErrorCode.USER_ALREADY_EXISTS, field="user_id"
         )
-    except NotFoundError:
-        raise
     except Exception as e:
-        logger.error(
-            f"Error adding member to organization (admin): {e!s}", exc_info=True
-        )
+        logger.exception("Error adding member to organization (admin): %s", e)
         raise
 
 
@@ -744,20 +859,10 @@ async def admin_remove_organization_member(
 ) -> Any:
     """Remove a user from an organization."""
     try:
-        org = await organization_crud.get(db, id=org_id)
-        if not org:
-            raise NotFoundError(
-                message=f"Organization {org_id} not found",
-                error_code=ErrorCode.NOT_FOUND,
-            )
+        org = await organization_service.get_organization(db, str(org_id))
+        user = await user_service.get_user(db, str(user_id))
 
-        user = await user_crud.get(db, id=user_id)
-        if not user:
-            raise NotFoundError(
-                message=f"User {user_id} not found", error_code=ErrorCode.USER_NOT_FOUND
-            )
-
-        success = await organization_crud.remove_user(
+        success = await organization_service.remove_member(
             db, organization_id=org_id, user_id=user_id
         )
 
@@ -768,7 +873,10 @@ async def admin_remove_organization_member(
             )
 
         logger.info(
-            f"Admin {admin.email} removed user {user.email} from organization {org.name}"
+            "Admin %s removed user %s from organization %s",
+            admin.email,
+            user.email,
+            org.name,
         )
 
         return MessageResponse(
@@ -778,10 +886,8 @@ async def admin_remove_organization_member(
 
     except NotFoundError:
         raise
-    except Exception as e:
-        logger.error(
-            f"Error removing member from organization (admin): {e!s}", exc_info=True
-        )
+    except Exception as e:  # pragma: no cover
+        logger.exception("Error removing member from organization (admin): %s", e)
         raise
 
 
@@ -811,7 +917,7 @@ async def admin_list_sessions(
     """List all sessions across all users with filtering and pagination."""
     try:
         # Get sessions with user info (eager loaded to prevent N+1)
-        sessions, total = await session_crud.get_all_sessions(
+        sessions, total = await session_service.get_all_sessions(
             db,
             skip=pagination.offset,
             limit=pagination.limit,
@@ -850,7 +956,10 @@ async def admin_list_sessions(
             session_responses.append(session_response)
 
         logger.info(
-            f"Admin {admin.email} listed {len(session_responses)} sessions (total: {total})"
+            "Admin %s listed %s sessions (total: %s)",
+            admin.email,
+            len(session_responses),
+            total,
         )
 
         pagination_meta = create_pagination_meta(
@@ -862,6 +971,6 @@ async def admin_list_sessions(
 
         return PaginatedResponse(data=session_responses, pagination=pagination_meta)
 
-    except Exception as e:
-        logger.error(f"Error listing sessions (admin): {e!s}", exc_info=True)
+    except Exception as e:  # pragma: no cover
+        logger.exception("Error listing sessions (admin): %s", e)
         raise

backend/app/api/routes/auth.py

@@ -15,16 +15,14 @@ from app.core.auth import (
     TokenExpiredError,
     TokenInvalidError,
     decode_token,
-    get_password_hash,
 )
 from app.core.database import get_db
 from app.core.exceptions import (
     AuthenticationError as AuthError,
     DatabaseError,
+    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 LogoutRequest, SessionCreate
@@ -39,6 +37,8 @@ from app.schemas.users import (
 )
 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
 
@@ -91,17 +91,18 @@ async def _create_login_session(
             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}: {session_err!s}", exc_info=True
-        )
+        logger.exception("Failed to create session for %s: %s", user.email, session_err)
 
 
 @router.post(
@@ -123,15 +124,21 @@ 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: {e!s}")
+        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.",
+        )
+    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: {e!s}", 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,
@@ -159,7 +166,7 @@ async def login(
 
         # 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,
@@ -175,14 +182,11 @@ async def login(
 
     except AuthenticationError as e:
         # Handle specific authentication errors like inactive accounts
-        logger.warning(f"Authentication failed: {e!s}")
+        logger.warning("Authentication failed: %s", e)
         raise AuthError(message=str(e), error_code=ErrorCode.INVALID_CREDENTIALS)
-    except AuthError:
-        # Re-raise custom auth exceptions without modification
-        raise
     except Exception as e:
         # Handle unexpected errors
-        logger.error(f"Unexpected error during login: {e!s}", 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,
@@ -224,13 +228,10 @@ async def login_oauth(
         # Return full token response with user data
         return tokens
     except AuthenticationError as e:
-        logger.warning(f"OAuth authentication failed: {e!s}")
+        logger.warning("OAuth authentication failed: %s", e)
         raise AuthError(message=str(e), error_code=ErrorCode.INVALID_CREDENTIALS)
-    except AuthError:
-        # Re-raise custom auth exceptions without modification
-        raise
     except Exception as e:
-        logger.error(f"Unexpected error during OAuth login: {e!s}", 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,
@@ -259,11 +260,12 @@ async def refresh_token(
         )
 
         # 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}"
+                "Refresh token used for inactive or non-existent session: %s",
+                refresh_payload.jti,
             )
             raise HTTPException(
                 status_code=status.HTTP_401_UNAUTHORIZED,
@@ -279,16 +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=UTC),
             )
         except Exception as session_err:
-            logger.error(
-                f"Failed to update session {session.id}: {session_err!s}", exc_info=True
-            )
+            logger.exception("Failed to update session %s: %s", session.id, session_err)
             # Continue anyway - tokens are already issued
 
         return tokens
@@ -311,7 +311,7 @@ async def refresh_token(
         # Re-raise HTTP exceptions (like session revoked)
         raise
     except Exception as e:
-        logger.error(f"Unexpected error during token refresh: {e!s}")
+        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.",
@@ -347,7 +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:
@@ -358,11 +358,12 @@ async def request_password_reset(
             await email_service.send_password_reset_email(
                 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}"
+                "Password reset requested for non-existent or inactive email: %s",
+                reset_request.email,
             )
 
         # Always return success to prevent email enumeration
@@ -371,7 +372,7 @@ async def request_password_reset(
             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: {e!s}", exc_info=True)
+        logger.exception("Error processing password reset request: %s", e)
         # Still return success to prevent information leakage
         return MessageResponse(
             success=True,
@@ -412,40 +413,34 @@ async def confirm_password_reset(
                 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(
+            deactivated_count = await session_service.deactivate_all_user_sessions(
                 db, user_id=str(user.id)
             )
             logger.info(
-                f"Password reset successful for {user.email}, invalidated {deactivated_count} sessions"
+                "Password reset successful for %s, invalidated %s sessions",
+                user.email,
+                deactivated_count,
             )
         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: {session_error!s}"
+                "Failed to invalidate sessions after password reset: %s", session_error
             )
 
         return MessageResponse(
@@ -456,7 +451,7 @@ async def confirm_password_reset(
     except HTTPException:
         raise
     except Exception as e:
-        logger.error(f"Error confirming password reset: {e!s}", exc_info=True)
+        logger.exception("Error confirming password reset: %s", e)
         await db.rollback()
         raise HTTPException(
             status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
@@ -506,19 +501,21 @@ async def logout(
             )
         except (TokenExpiredError, TokenInvalidError) as e:
             # Even if token is expired/invalid, try to deactivate session
-            logger.warning(f"Logout with invalid/expired token: {e!s}")
+            logger.warning("Logout with invalid/expired token: %s", e)
             # Don't fail - return success anyway
             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,
@@ -526,17 +523,20 @@ async def logout(
                 )
 
             # 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})"
+                "Logout requested for non-existent session (JTI: %s)",
+                refresh_payload.jti,
             )
 
         return MessageResponse(success=True, message="Logged out successfully")
@@ -544,9 +544,7 @@ async def logout(
     except HTTPException:
         raise
     except Exception as e:
-        logger.error(
-            f"Error during logout for user {current_user.id}: {e!s}", 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")
 
@@ -584,12 +582,12 @@ async def logout_all(
     """
     try:
         # Deactivate all sessions for this user
-        count = await session_crud.deactivate_all_user_sessions(
+        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)"
+            "User %s logged out from all devices (%s sessions)", current_user.id, count
         )
 
         return MessageResponse(
@@ -598,9 +596,7 @@ async def logout_all(
         )
 
     except Exception as e:
-        logger.error(
-            f"Error during logout-all for user {current_user.id}: {e!s}", 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,

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

@@ -15,8 +15,6 @@ 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 ErrorCode, NotFoundError
-from app.crud.organization import organization as organization_crud
 from app.models.user import User
 from app.schemas.common import (
     PaginatedResponse,
@@ -28,6 +26,7 @@ from app.schemas.organizations import (
     OrganizationResponse,
     OrganizationUpdate,
 )
+from app.services.organization_service import organization_service
 
 logger = logging.getLogger(__name__)
 
@@ -54,7 +53,7 @@ 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(
+        orgs_data = await organization_service.get_user_organizations_with_details(
             db, user_id=current_user.id, is_active=is_active
         )
 
@@ -78,7 +77,7 @@ async def get_my_organizations(
         return orgs_with_data
 
     except Exception as e:
-        logger.error(f"Error getting user organizations: {e!s}", exc_info=True)
+        logger.exception("Error getting user organizations: %s", e)
         raise
 
 
@@ -100,13 +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,
@@ -116,16 +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(
+            "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: {e!s}", exc_info=True)
+        logger.exception("Error getting organization: %s", e)
         raise
 
 
@@ -149,7 +140,7 @@ 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,
@@ -169,7 +160,7 @@ async def get_organization_members(
         return PaginatedResponse(data=member_responses, pagination=pagination_meta)
 
     except Exception as e:
-        logger.error(f"Error getting organization members: {e!s}", exc_info=True)
+        logger.exception("Error getting organization members: %s", e)
         raise
 
 
@@ -192,16 +183,12 @@ 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)
+        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(
-            f"User {current_user.email} updated organization {updated_org.name}"
+            "User %s updated organization %s", current_user.email, updated_org.name
         )
 
         org_dict = {
@@ -213,14 +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(
+            "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: {e!s}", exc_info=True)
+        logger.exception("Error updating organization: %s", e)
         raise

backend/app/api/routes/sessions.py

@@ -17,10 +17,10 @@ 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 AuthorizationError, ErrorCode, NotFoundError
-from app.crud.session import session as session_crud
 from app.models.user import User
 from app.schemas.common import MessageResponse
 from app.schemas.sessions import SessionListResponse, SessionResponse
+from app.services.session_service import session_service
 
 router = APIRouter()
 logger = logging.getLogger(__name__)
@@ -60,7 +60,7 @@ async def list_my_sessions(
     """
     try:
         # Get all active sessions for user
-        sessions = await session_crud.get_user_sessions(
+        sessions = await session_service.get_user_sessions(
             db, user_id=str(current_user.id), active_only=True
         )
 
@@ -74,9 +74,7 @@ async def list_my_sessions(
                 # For now, we'll mark current based on most recent activity
             except Exception as e:
                 # Optional token parsing - silently ignore failures
-                logger.debug(
-                    f"Failed to decode access token for session marking: {e!s}"
-                )
+                logger.debug("Failed to decode access token for session marking: %s", e)
 
         # Convert to response format
         session_responses = []
@@ -98,7 +96,7 @@ async def list_my_sessions(
             session_responses.append(session_response)
 
         logger.info(
-            f"User {current_user.id} listed {len(session_responses)} active sessions"
+            "User %s listed %s active sessions", current_user.id, len(session_responses)
         )
 
         return SessionListResponse(
@@ -106,9 +104,7 @@ async def list_my_sessions(
         )
 
     except Exception as e:
-        logger.error(
-            f"Error listing sessions for user {current_user.id}: {e!s}", 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",
@@ -150,7 +146,7 @@ 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(
@@ -161,8 +157,10 @@ async def revoke_session(
         # 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",
@@ -170,11 +168,13 @@ async def revoke_session(
             )
 
         # 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(
@@ -185,7 +185,7 @@ async def revoke_session(
     except (NotFoundError, AuthorizationError):
         raise
     except Exception as e:
-        logger.error(f"Error revoking session {session_id}: {e!s}", 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",
@@ -224,12 +224,12 @@ async def cleanup_expired_sessions(
     """
     try:
         # Use optimized bulk DELETE instead of N individual deletes
-        deleted_count = await session_crud.cleanup_expired_for_user(
+        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"
+            "User %s cleaned up %s expired sessions", current_user.id, deleted_count
         )
 
         return MessageResponse(
@@ -237,9 +237,8 @@ async def cleanup_expired_sessions(
         )
 
     except Exception as e:
-        logger.error(
-            f"Error cleaning up sessions for user {current_user.id}: {e!s}",
-            exc_info=True,
+        logger.exception(
+            "Error cleaning up sessions for user %s: %s", current_user.id, e
         )
         await db.rollback()
         raise HTTPException(

backend/app/api/routes/users.py

@@ -1,5 +1,5 @@
 """
-User management endpoints for CRUD operations.
+User management endpoints for database operations.
 """
 
 import logging
@@ -13,8 +13,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.api.dependencies.auth import get_current_superuser, get_current_user
 from app.core.database import get_db
-from app.core.exceptions import AuthorizationError, ErrorCode, NotFoundError
-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 (
     MessageResponse,
@@ -25,6 +24,7 @@ from app.schemas.common import (
 )
 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__)
 
@@ -71,7 +71,7 @@ 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,
@@ -90,7 +90,7 @@ async def list_users(
 
         return PaginatedResponse(data=users, pagination=pagination_meta)
     except Exception as e:
-        logger.error(f"Error listing users: {e!s}", exc_info=True)
+        logger.exception("Error listing users: %s", e)
         raise
 
 
@@ -107,7 +107,9 @@ async def list_users(
     """,
     operation_id="get_current_user_profile",
 )
-def get_current_user_profile(current_user: User = Depends(get_current_user)) -> Any:
+async def get_current_user_profile(
+    current_user: User = Depends(get_current_user),
+) -> Any:
     """Get current user's profile."""
     return current_user
 
@@ -138,18 +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}: {e!s}")
+        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}: {e!s}", exc_info=True
-        )
+        logger.exception("Unexpected error updating user %s: %s", current_user.id, e)
         raise
 
 
@@ -182,7 +182,9 @@ 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",
@@ -190,13 +192,7 @@ async def get_user_by_id(
         )
 
     # 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
 
 
@@ -233,7 +229,9 @@ 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",
@@ -241,22 +239,17 @@ async def update_user(
         )
 
     # 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}: {e!s}")
+        logger.error("Error updating user %s: %s", user_id, e)
         raise
     except Exception as e:
-        logger.error(f"Unexpected error updating user {user_id}: {e!s}", exc_info=True)
+        logger.exception("Unexpected error updating user %s: %s", user_id, e)
         raise
 
 
@@ -296,19 +289,19 @@ async def change_current_user_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"
             )
     except AuthenticationError as e:
         logger.warning(
-            f"Failed password change attempt for user {current_user.id}: {e!s}"
+            "Failed password change attempt for user %s: %s", current_user.id, e
         )
         raise AuthorizationError(
             message=str(e), error_code=ErrorCode.INVALID_CREDENTIALS
         )
     except Exception as e:
-        logger.error(f"Error changing password for user {current_user.id}: {e!s}")
+        logger.error("Error changing password for user %s: %s", current_user.id, e)
         raise
 
 
@@ -346,24 +339,19 @@ async def delete_user(
             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"
         )
     except ValueError as e:
-        logger.error(f"Error deleting user {user_id}: {e!s}")
+        logger.error("Error deleting user %s: %s", user_id, e)
         raise
     except Exception as e:
-        logger.error(f"Unexpected error deleting user {user_id}: {e!s}", exc_info=True)
+        logger.exception("Unexpected error deleting user %s: %s", user_id, e)
         raise

backend/app/core/auth.py

@@ -1,23 +1,21 @@
 import asyncio
-import logging
 import uuid
 from datetime import UTC, datetime, timedelta
 from functools import partial
 from typing import Any
 
-from jose import JWTError, jwt
-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
 
-# Suppress passlib bcrypt warnings about ident
-logging.getLogger("passlib").setLevel(logging.ERROR)
-
-# Password hashing context
-pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
-
 
 # Custom exceptions for auth
 class AuthError(Exception):
@@ -37,13 +35,16 @@ class TokenMissingClaimError(AuthError):
 
 
 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:
@@ -60,9 +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)
     )
 
 
@@ -80,8 +81,8 @@ 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(
@@ -121,11 +122,7 @@ 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(
@@ -154,11 +151,7 @@ def create_refresh_token(
         "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: str | None = None) -> TokenPayload:
@@ -198,7 +191,7 @@ def decode_token(token: str, verify_type: str | None = 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
@@ -219,10 +212,11 @@ def decode_token(token: str, verify_type: str | None = 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")

backend/app/core/config.py

@@ -14,6 +14,10 @@ class Settings(BaseSettings):
         default="development",
         description="Environment: development, staging, or production",
     )
+    DEMO_MODE: bool = Field(
+        default=False,
+        description="Enable demo mode (relaxed security, demo users)",
+    )
 
     # Security: Content Security Policy
     # Set to False to disable CSP entirely (not recommended)
@@ -72,6 +76,60 @@ class Settings(BaseSettings):
         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: str | None = Field(
         default=None, description="Email for first superuser account"
@@ -110,11 +168,21 @@ class Settings(BaseSettings):
 
     @field_validator("FIRST_SUPERUSER_PASSWORD")
     @classmethod
-    def validate_superuser_password(cls, v: str | None) -> str | None:
+    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")
 

backend/app/core/database.py

@@ -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: {e!s}")
+            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: {e!s}")
+        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

@@ -143,8 +143,11 @@ 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(
@@ -186,7 +189,9 @@ async def validation_exception_handler(
             )
         )
 
-    logger.warning(f"Validation error: {len(errors)} errors (path: {request.url.path})")
+    logger.warning(
+        "Validation error: %s errors (path: %s)", len(errors), request.url.path
+    )
 
     error_response = ErrorResponse(errors=errors)
 
@@ -218,11 +223,14 @@ async def http_exception_handler(request: Request, exc: HTTPException) -> JSONRe
     )
 
     logger.warning(
-        f"HTTP exception: {exc.status_code} - {exc.detail} (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(
@@ -239,10 +247,11 @@ 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__} - {exc!s} "
-        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
@@ -254,7 +263,7 @@ async def unhandled_exception_handler(request: Request, exc: Exception) -> JSONR
         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(

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__ = ["organization", "session_crud", "user"]

backend/app/init_db.py

@@ -6,12 +6,20 @@ Creates the first superuser if configured and doesn't already exist.
 """
 
 import asyncio
+import json
 import logging
+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__)
@@ -26,21 +34,27 @@ async def init_db() -> User | None:
     """
     # 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
@@ -52,19 +66,143 @@ async def init_db() -> User | None:
                 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

backend/app/main.py

@@ -1,7 +1,7 @@
 import logging
 import os
 from contextlib import asynccontextmanager
-from datetime import datetime
+from datetime import UTC, datetime
 from typing import Any
 
 from apscheduler.schedulers.asyncio import AsyncIOScheduler
@@ -14,8 +14,9 @@ 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,
@@ -71,6 +72,7 @@ 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("Starting app!!!")
@@ -293,7 +295,7 @@ async def health_check() -> JSONResponse:
     """
     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": {},
@@ -318,9 +320,13 @@ async def health_check() -> JSONResponse:
             "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)
 
 
 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

@@ -7,6 +7,15 @@ Imports all models to ensure they're registered with SQLAlchemy.
 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
@@ -16,6 +25,12 @@ from .user_session import UserSession
 
 __all__ = [
     "Base",
+    "OAuthAccount",
+    "OAuthAuthorizationCode",
+    "OAuthClient",
+    "OAuthConsent",
+    "OAuthProviderRefreshToken",
+    "OAuthState",
     "Organization",
     "OrganizationRole",
     "TimestampMixin",

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

@@ -10,6 +10,9 @@ 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"

backend/app/models/user.py

@@ -6,10 +6,19 @@ from .base import Base, TimestampMixin, UUIDMixin
 
 
 class User(Base, UUIDMixin, TimestampMixin):
+    """
+    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))
@@ -23,6 +32,19 @@ class User(Base, UUIDMixin, TimestampMixin):
     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}>"

backend/app/models/user_organization.py

@@ -44,7 +44,7 @@ class UserOrganization(Base, TimestampMixin):
         Enum(OrganizationRole),
         default=OrganizationRole.MEMBER,
         nullable=False,
-        index=True,
+        # Note: index defined in __table_args__ as ix_user_org_role
     )
     is_active = Column(Boolean, default=True, nullable=False, index=True)
 

backend/app/models/user_session.py

@@ -22,6 +22,9 @@ 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"
@@ -73,7 +76,11 @@ class UserSession(Base, UUIDMixin, TimestampMixin):
         """Check if session has expired."""
         from datetime import datetime
 
-        return self.expires_at < datetime.now(UTC)
+        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."""

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

@@ -1,6 +1,6 @@
-# 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.
 """
@@ -18,6 +18,11 @@ 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__)
 
@@ -26,16 +31,16 @@ CreateSchemaType = TypeVar("CreateSchemaType", bound=BaseModel)
 UpdateSchemaType = TypeVar("UpdateSchemaType", bound=BaseModel)
 
 
-class CRUDBase[
+class BaseRepository[
     ModelType: Base,
     CreateSchemaType: BaseModel,
     UpdateSchemaType: BaseModel,
 ]:
-    """Async CRUD operations for a model."""
+    """Async repository operations for a model."""
 
     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
@@ -56,26 +61,19 @@ class CRUDBase[
 
         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} - {e!s}")
+            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)
@@ -83,7 +81,9 @@ class CRUDBase[
             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}: {e!s}")
+            logger.error(
+                "Error retrieving %s with id %s: %s", self.model.__name__, id, e
+            )
             raise
 
     async def get_multi(
@@ -96,28 +96,17 @@ class CRUDBase[
     ) -> 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)
@@ -126,7 +115,7 @@ class CRUDBase[
             return list(result.scalars().all())
         except Exception as e:
             logger.error(
-                f"Error retrieving multiple {self.model.__name__} records: {e!s}"
+                "Error retrieving multiple %s records: %s", self.model.__name__, e
             )
             raise
 
@@ -136,9 +125,8 @@ class CRUDBase[
         """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)
@@ -152,22 +140,24 @@ class CRUDBase[
             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}"
+                    "Duplicate entry attempted for %s: %s",
+                    self.model.__name__,
+                    error_msg,
                 )
-                raise ValueError(
+                raise DuplicateEntryError(
                     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.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__}: {e!s}")
-            raise ValueError(f"Database operation failed: {e!s}")
+            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__}: {e!s}", exc_info=True
-            )
+            logger.exception("Unexpected error creating %s: %s", self.model.__name__, e)
             raise
 
     async def update(
@@ -198,34 +188,35 @@ class CRUDBase[
             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}"
+                    "Duplicate entry attempted for %s: %s",
+                    self.model.__name__,
+                    error_msg,
                 )
-                raise ValueError(
+                raise DuplicateEntryError(
                     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.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__}: {e!s}")
-            raise ValueError(f"Database operation failed: {e!s}")
+            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__}: {e!s}", exc_info=True
-            )
+            logger.exception("Unexpected error updating %s: %s", self.model.__name__, e)
             raise
 
     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} - {e!s}")
+            logger.warning("Invalid UUID format for deletion: %s - %s", id, e)
             return None
 
         try:
@@ -236,7 +227,7 @@ class CRUDBase[
 
             if obj is None:
                 logger.warning(
-                    f"{self.model.__name__} with id {id} not found for deletion"
+                    "%s with id %s not found for deletion", self.model.__name__, id
                 )
                 return None
 
@@ -246,15 +237,16 @@ class CRUDBase[
         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(
+            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}: {e!s}",
-                exc_info=True,
+            logger.exception(
+                "Error deleting %s with id %s: %s", self.model.__name__, id, e
             )
             raise
 
@@ -267,65 +259,53 @@ class CRUDBase[
         sort_by: str | None = None,
         sort_order: str = "asc",
         filters: dict[str, Any] | None = None,
-    ) -> tuple[list[ModelType], int]:
+    ) -> 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"):
                 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:
+        except Exception as e:  # pragma: no cover
             logger.error(
-                f"Error retrieving paginated {self.model.__name__} records: {e!s}"
+                "Error retrieving paginated %s records: %s", self.model.__name__, e
             )
             raise
 
@@ -335,7 +315,7 @@ class CRUDBase[
             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: {e!s}")
+            logger.error("Error counting %s records: %s", self.model.__name__, e)
             raise
 
     async def exists(self, db: AsyncSession, id: str) -> bool:
@@ -351,14 +331,13 @@ class CRUDBase[
         """
         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} - {e!s}")
+            logger.warning("Invalid UUID format for soft deletion: %s - %s", id, e)
             return None
 
         try:
@@ -369,18 +348,16 @@ class CRUDBase[
 
             if obj is None:
                 logger.warning(
-                    f"{self.model.__name__} with id {id} not found for soft deletion"
+                    "%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(
+                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(UTC)
             db.add(obj)
             await db.commit()
@@ -388,9 +365,8 @@ class CRUDBase[
             return obj
         except Exception as e:
             await db.rollback()
-            logger.error(
-                f"Error soft deleting {self.model.__name__} with id {id}: {e!s}",
-                exc_info=True,
+            logger.exception(
+                "Error soft deleting %s with id %s: %s", self.model.__name__, id, e
             )
             raise
 
@@ -400,18 +376,16 @@ class CRUDBase[
 
         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} - {e!s}")
+            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"):
                 result = await db.execute(
                     select(self.model).where(
@@ -420,18 +394,19 @@ class CRUDBase[
                 )
                 obj = result.scalar_one_or_none()
             else:
-                logger.error(f"{self.model.__name__} does not support soft deletes")
-                raise ValueError(
+                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"
+                    "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()
@@ -439,8 +414,7 @@ class CRUDBase[
             return obj
         except Exception as e:
             await db.rollback()
-            logger.error(
-                f"Error restoring {self.model.__name__} with id {id}: {e!s}",
-                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

@@ -1,5 +1,5 @@
-# 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 Any
@@ -9,10 +9,11 @@ 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 OrganizationRole, UserOrganization
+from app.repositories.base import BaseRepository
 from app.schemas.organizations import (
     OrganizationCreate,
     OrganizationUpdate,
@@ -21,8 +22,10 @@ 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) -> Organization | None:
         """Get organization by slug."""
@@ -32,7 +35,7 @@ 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}: {e!s}")
+            logger.error("Error getting organization by slug %s: %s", slug, e)
             raise
 
     async def create(
@@ -54,18 +57,20 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
         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(
+            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(f"Integrity error creating organization: {error_msg}")
-            raise ValueError(f"Database integrity error: {error_msg}")
+            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: {e!s}", exc_info=True
-            )
+            logger.exception("Unexpected error creating organization: %s", e)
             raise
 
     async def get_multi_with_filters(
@@ -79,16 +84,10 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
         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)
-        """
+        """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)
 
@@ -100,26 +99,23 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
                 )
                 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: {e!s}")
+            logger.error("Error getting organizations with filters: %s", e)
             raise
 
     async def get_member_count(self, db: AsyncSession, *, organization_id: UUID) -> int:
@@ -136,7 +132,7 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
             return result.scalar_one() or 0
         except Exception as e:
             logger.error(
-                f"Error getting member count for organization {organization_id}: {e!s}"
+                "Error getting member count for organization %s: %s", organization_id, e
             )
             raise
 
@@ -149,16 +145,8 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
         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.
-        This eliminates the N+1 query problem.
-
-        Returns:
-            Tuple of (list of dicts with org and member_count, total count)
-        """
+        """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,
@@ -181,10 +169,10 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
                 .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}%"),
@@ -193,17 +181,15 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
                 )
                 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)
             )
@@ -211,7 +197,6 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
             result = await db.execute(query)
             rows = result.all()
 
-            # Convert to list of dicts
             orgs_with_counts = [
                 {"organization": org, "member_count": member_count}
                 for org, member_count in rows
@@ -220,9 +205,7 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
             return orgs_with_counts, total
 
         except Exception as e:
-            logger.error(
-                f"Error getting organizations with member counts: {e!s}", exc_info=True
-            )
+            logger.exception("Error getting organizations with member counts: %s", e)
             raise
 
     async def add_user(
@@ -236,7 +219,6 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
     ) -> 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_(
@@ -248,7 +230,6 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
             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
@@ -257,9 +238,10 @@ 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,
@@ -273,11 +255,11 @@ 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: {e!s}")
-            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: {e!s}", exc_info=True)
+            logger.exception("Error adding user to organization: %s", e)
             raise
 
     async def remove_user(
@@ -303,7 +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: {e!s}", exc_info=True)
+            logger.exception("Error removing user from organization: %s", e)
             raise
 
     async def update_user_role(
@@ -338,7 +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: {e!s}", exc_info=True)
+            logger.exception("Error updating user role: %s", e)
             raise
 
     async def get_organization_members(
@@ -348,16 +330,10 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
         organization_id: UUID,
         skip: int = 0,
         limit: int = 100,
-        is_active: bool = True,
+        is_active: bool | None = 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)
-        """
+        """Get members of an organization with user details."""
         try:
-            # Build query with join
             query = (
                 select(UserOrganization, User)
                 .join(User, UserOrganization.user_id == User.id)
@@ -367,7 +343,6 @@ 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)
@@ -381,7 +356,6 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
             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)
@@ -406,11 +380,11 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
 
             return members, total
         except Exception as e:
-            logger.error(f"Error getting organization members: {e!s}")
+            logger.error("Error getting organization members: %s", e)
             raise
 
     async def get_user_organizations(
-        self, db: AsyncSession, *, user_id: UUID, is_active: bool = True
+        self, db: AsyncSession, *, user_id: UUID, is_active: bool | None = True
     ) -> list[Organization]:
         """Get all organizations a user belongs to."""
         try:
@@ -429,21 +403,14 @@ 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: {e!s}")
+            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
+        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.
-        Eliminates N+1 problem by using subquery for member counts.
-
-        Returns:
-            List of dicts with organization, role, and member_count
-        """
+        """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,
@@ -454,7 +421,6 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
                 .subquery()
             )
 
-            # Main query with JOIN to get org, role, and member count
             query = (
                 select(
                     Organization,
@@ -486,9 +452,7 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
             ]
 
         except Exception as e:
-            logger.error(
-                f"Error getting user organizations with details: {e!s}", exc_info=True
-            )
+            logger.exception("Error getting user organizations with details: %s", e)
             raise
 
     async def get_user_role_in_org(
@@ -507,9 +471,9 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
             )
             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: {e!s}")
+            logger.error("Error getting user role in org: %s", e)
             raise
 
     async def is_user_org_owner(
@@ -531,5 +495,5 @@ class CRUDOrganization(CRUDBase[Organization, OrganizationCreate, OrganizationUp
         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

@@ -1,6 +1,5 @@
-"""
-Async CRUD operations for user sessions using SQLAlchemy 2.0 patterns.
-"""
+# app/repositories/session.py
+"""Repository for UserSession model async database operations using SQLAlchemy 2.0 patterns."""
 
 import logging
 import uuid
@@ -11,49 +10,32 @@ from sqlalchemy import and_, delete, func, select, update
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy.orm import joinedload
 
-from app.crud.base import CRUDBase
+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 CRUDSession(CRUDBase[UserSession, SessionCreate, SessionUpdate]):
-    """Async CRUD operations for user sessions."""
+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.
-
-        Args:
-            db: Database session
-            jti: Refresh token JWT ID
-
-        Returns:
-            UserSession if found, None otherwise
-        """
+        """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(f"Error getting session by JTI {jti}: {e!s}")
+            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.
-
-        Args:
-            db: Database session
-            jti: Refresh token JWT ID
-
-        Returns:
-            Active UserSession if found, None otherwise
-        """
+        """Get active session by refresh token JTI."""
         try:
             result = await db.execute(
                 select(UserSession).where(
@@ -65,7 +47,7 @@ class CRUDSession(CRUDBase[UserSession, SessionCreate, SessionUpdate]):
             )
             return result.scalar_one_or_none()
         except Exception as e:
-            logger.error(f"Error getting active session by JTI {jti}: {e!s}")
+            logger.error("Error getting active session by JTI %s: %s", jti, e)
             raise
 
     async def get_user_sessions(
@@ -76,25 +58,12 @@ class CRUDSession(CRUDBase[UserSession, SessionCreate, SessionUpdate]):
         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
-        """
+        """Get all sessions for a user with optional eager loading."""
         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))
 
@@ -105,25 +74,13 @@ class CRUDSession(CRUDBase[UserSession, SessionCreate, SessionUpdate]):
             result = await db.execute(query)
             return list(result.scalars().all())
         except Exception as e:
-            logger.error(f"Error getting sessions for user {user_id}: {e!s}")
+            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.
-
-        Args:
-            db: Database session
-            obj_in: SessionCreate schema with session data
-
-        Returns:
-            Created UserSession
-
-        Raises:
-            ValueError: If session creation fails
-        """
+        """Create a new user session."""
         try:
             db_obj = UserSession(
                 user_id=obj_in.user_id,
@@ -143,33 +100,26 @@ class CRUDSession(CRUDBase[UserSession, SessionCreate, SessionUpdate]):
             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})"
+                "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.error(f"Error creating session: {e!s}", exc_info=True)
-            raise ValueError(f"Failed to create session: {e!s}")
+            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).
-
-        Args:
-            db: Database session
-            session_id: Session UUID
-
-        Returns:
-            Deactivated UserSession if found, None otherwise
-        """
+        """Deactivate a session (logout from device)."""
         try:
             session = await self.get(db, id=session_id)
             if not session:
-                logger.warning(f"Session {session_id} not found for deactivation")
+                logger.warning("Session %s not found for deactivation", session_id)
                 return None
 
             session.is_active = False
@@ -178,31 +128,23 @@ class CRUDSession(CRUDBase[UserSession, SessionCreate, SessionUpdate]):
             await db.refresh(session)
 
             logger.info(
-                f"Session {session_id} deactivated for user {session.user_id} "
-                f"({session.device_name})"
+                "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(f"Error deactivating session {session_id}: {e!s}")
+            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).
-
-        Args:
-            db: Database session
-            user_id: User ID
-
-        Returns:
-            Number of sessions deactivated
-        """
+        """Deactivate all active sessions for a user (logout from all devices)."""
         try:
-            # Convert user_id string to UUID if needed
             user_uuid = UUID(user_id) if isinstance(user_id, str) else user_id
 
             stmt = (
@@ -216,27 +158,18 @@ class CRUDSession(CRUDBase[UserSession, SessionCreate, SessionUpdate]):
 
             count = result.rowcount
 
-            logger.info(f"Deactivated {count} sessions for user {user_id}")
+            logger.info("Deactivated %s sessions for user %s", count, user_id)
 
             return count
         except Exception as e:
             await db.rollback()
-            logger.error(f"Error deactivating all sessions for user {user_id}: {e!s}")
+            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.
-
-        Args:
-            db: Database session
-            session: UserSession object
-
-        Returns:
-            Updated UserSession
-        """
+        """Update the last_used_at timestamp for a session."""
         try:
             session.last_used_at = datetime.now(UTC)
             db.add(session)
@@ -245,7 +178,7 @@ class CRUDSession(CRUDBase[UserSession, SessionCreate, SessionUpdate]):
             return session
         except Exception as e:
             await db.rollback()
-            logger.error(f"Error updating last_used for session {session.id}: {e!s}")
+            logger.error("Error updating last_used for session %s: %s", session.id, e)
             raise
 
     async def update_refresh_token(
@@ -256,20 +189,7 @@ class CRUDSession(CRUDBase[UserSession, SessionCreate, SessionUpdate]):
         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
-        """
+        """Update session with new refresh token JTI and expiration."""
         try:
             session.refresh_token_jti = new_jti
             session.expires_at = new_expires_at
@@ -281,32 +201,16 @@ class CRUDSession(CRUDBase[UserSession, SessionCreate, SessionUpdate]):
         except Exception as e:
             await db.rollback()
             logger.error(
-                f"Error updating refresh token for session {session.id}: {e!s}"
+                "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.
-
-        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
-        """
+        """Clean up expired sessions using optimized bulk DELETE."""
         try:
             cutoff_date = datetime.now(UTC) - timedelta(days=keep_days)
             now = datetime.now(UTC)
 
-            # Use bulk DELETE with WHERE clause - single query
             stmt = delete(UserSession).where(
                 and_(
                     UserSession.is_active == False,  # noqa: E712
@@ -321,38 +225,25 @@ class CRUDSession(CRUDBase[UserSession, SessionCreate, SessionUpdate]):
             count = result.rowcount
 
             if count > 0:
-                logger.info(f"Cleaned up {count} expired sessions using bulk DELETE")
+                logger.info("Cleaned up %s expired sessions using bulk DELETE", count)
 
             return count
         except Exception as e:
             await db.rollback()
-            logger.error(f"Error cleaning up expired sessions: {e!s}")
+            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.
-
-        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
-        """
+        """Clean up expired and inactive sessions for a specific user."""
         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}")
+                logger.error("Invalid UUID format: %s", user_id)
+                raise InvalidInputError(f"Invalid user ID format: {user_id}")
 
             now = datetime.now(UTC)
 
-            # Use bulk DELETE with WHERE clause - single query
             stmt = delete(UserSession).where(
                 and_(
                     UserSession.user_id == uuid_obj,
@@ -368,30 +259,22 @@ class CRUDSession(CRUDBase[UserSession, SessionCreate, SessionUpdate]):
 
             if count > 0:
                 logger.info(
-                    f"Cleaned up {count} expired sessions for user {user_id} using bulk DELETE"
+                    "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(
-                f"Error cleaning up expired sessions for user {user_id}: {e!s}"
+                "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.
-
-        Args:
-            db: Database session
-            user_id: User ID
-
-        Returns:
-            Number of active sessions
-        """
+        """Get count of active sessions for a user."""
         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(
@@ -401,7 +284,7 @@ class CRUDSession(CRUDBase[UserSession, SessionCreate, SessionUpdate]):
             )
             return result.scalar_one()
         except Exception as e:
-            logger.error(f"Error counting sessions for user {user_id}: {e!s}")
+            logger.error("Error counting sessions for user %s: %s", user_id, e)
             raise
 
     async def get_all_sessions(
@@ -413,31 +296,16 @@ class CRUDSession(CRUDBase[UserSession, SessionCreate, SessionUpdate]):
         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)
-        """
+        """Get all sessions across all users with pagination (admin only)."""
         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)
 
-            # Get total count
             count_query = select(func.count(UserSession.id))
             if active_only:
                 count_query = count_query.where(UserSession.is_active)
@@ -445,7 +313,6 @@ class CRUDSession(CRUDBase[UserSession, SessionCreate, SessionUpdate]):
             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)
@@ -458,9 +325,9 @@ class CRUDSession(CRUDBase[UserSession, SessionCreate, SessionUpdate]):
             return sessions, total
 
         except Exception as e:
-            logger.error(f"Error getting all sessions: {e!s}", exc_info=True)
+            logger.exception("Error getting all sessions: %s", e)
             raise
 
 
-# Create singleton instance
-session = CRUDSession(UserSession)
+# Singleton instance
+session_repo = SessionRepository(UserSession)

backend/app/repositories/user.py

@@ -1,5 +1,5 @@
-# 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 UTC, datetime
@@ -11,15 +11,16 @@ 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) -> User | None:
         """Get user by email address."""
@@ -27,13 +28,12 @@ class CRUDUser(CRUDBase[User, UserCreate, UserUpdate]):
             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}: {e!s}")
+            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(
@@ -57,13 +57,49 @@ class CRUDUser(CRUDBase[User, UserCreate, UserUpdate]):
             await db.rollback()
             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: {e!s}", exc_info=True)
+            logger.exception("Unexpected error creating user: %s", e)
+            raise
+
+    async def create_oauth_user(
+        self,
+        db: AsyncSession,
+        *,
+        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(
@@ -75,8 +111,6 @@ 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"]
@@ -85,6 +119,15 @@ class CRUDUser(CRUDBase[User, UserCreate, UserUpdate]):
 
         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,
@@ -96,43 +139,23 @@ class CRUDUser(CRUDBase[User, UserCreate, UserUpdate]):
         filters: dict[str, Any] | None = None,
         search: str | None = 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
+        """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}%"),
@@ -141,14 +164,12 @@ class CRUDUser(CRUDBase[User, UserCreate, UserUpdate]):
                 )
                 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":
@@ -156,7 +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())
@@ -164,32 +184,21 @@ class CRUDUser(CRUDBase[User, UserCreate, UserUpdate]):
             return users, total
 
         except Exception as e:
-            logger.error(f"Error retrieving paginated users: {e!s}")
+            logger.error("Error retrieving paginated users: %s", e)
             raise
 
     async def bulk_update_status(
         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
+                .where(User.deleted_at.is_(None))
                 .values(is_active=is_active, updated_at=datetime.now(UTC))
             )
 
@@ -197,12 +206,14 @@ class CRUDUser(CRUDBase[User, UserCreate, UserUpdate]):
             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: {e!s}", exc_info=True)
+            logger.exception("Error bulk updating user status: %s", e)
             raise
 
     async def bulk_soft_delete(
@@ -212,34 +223,20 @@ class CRUDUser(CRUDBase[User, UserCreate, UserUpdate]):
         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(UTC),
                     is_active=False,
@@ -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: {e!s}", 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/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

@@ -48,7 +48,7 @@ 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):

backend/app/schemas/users.py

@@ -23,6 +23,7 @@ class UserBase(BaseModel):
 class UserCreate(UserBase):
     password: str
     is_superuser: bool = False
+    is_active: bool = True
 
     @field_validator("password")
     @classmethod

backend/app/schemas/validators.py

@@ -60,6 +60,15 @@ 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")

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

@@ -2,7 +2,6 @@
 import logging
 from uuid import UUID
 
-from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.core.auth import (
@@ -14,12 +13,18 @@ from app.core.auth import (
     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"""
@@ -39,10 +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
@@ -71,40 +78,23 @@ 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: {e!s}", exc_info=True)
+            logger.exception("Error creating user: %s", e)
             raise AuthenticationError(f"Failed to create user: {e!s}")
 
     @staticmethod
@@ -168,8 +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")
 
@@ -177,7 +166,7 @@ class AuthService:
             return AuthService.create_tokens(user)
 
         except (TokenExpiredError, TokenInvalidError) as e:
-            logger.warning(f"Token refresh failed: {e!s}")
+            logger.warning("Token refresh failed: %s", e)
             raise
 
     @staticmethod
@@ -200,8 +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")
 
@@ -210,10 +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:
@@ -222,7 +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}: {e!s}", exc_info=True
-            )
+            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

@@ -58,8 +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:")
@@ -199,7 +199,7 @@ The {settings.PROJECT_NAME} Team
                 text_content=text_content,
             )
         except Exception as e:
-            logger.error(f"Failed to send password reset email to {to_email}: {e!s}")
+            logger.error("Failed to send password reset email to %s: %s", to_email, e)
             return False
 
     async def send_email_verification(
@@ -287,7 +287,7 @@ The {settings.PROJECT_NAME} Team
                 text_content=text_content,
             )
         except Exception as e:
-            logger.error(f"Failed to send verification email to {to_email}: {e!s}")
+            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

@@ -8,7 +8,7 @@ import logging
 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__)
 
@@ -32,15 +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: {e!s}", exc_info=True)
+            logger.exception("Error during session cleanup: %s", e)
             return 0
 
 
@@ -79,10 +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: {e!s}", 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/test_utils.py

@@ -65,10 +65,10 @@ 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,
     )

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/)

backend/entrypoint.sh

@@ -1,12 +1,22 @@
-#!/bin/bash
+#!/bin/sh
 set -e
 echo "Starting Backend"
 
+# Ensure the project's virtualenv binaries are on PATH so commands like
+# 'uvicorn' work even when not prefixed by 'uv run'. This matches how uv
+# installs the env into /app/.venv in our containers.
+if [ -d "/app/.venv/bin" ]; then
+  export PATH="/app/.venv/bin:$PATH"
+fi
+
 # Apply database migrations
-uv run alembic upgrade head
+# Avoid installing the project in editable mode (which tries to write egg-info)
+# when running inside a bind-mounted volume with restricted permissions.
+# See: https://github.com/astral-sh/uv (use --no-project to skip project build)
+uv run --no-project alembic upgrade head
 
 # Initialize database (creates first superuser if needed)
-uv run python app/init_db.py
+uv run --no-project python app/init_db.py
 
 # Execute the command passed to docker run
 exec "$@"

backend/migrate.py

@@ -2,8 +2,32 @@
 """
 Database migration helper script.
 Provides convenient commands for generating and applying Alembic migrations.
+
+Usage:
+    # Generate migration (auto-increments revision ID: 0001, 0002, etc.)
+    python migrate.py --local generate "Add new field"
+    python migrate.py --local auto "Add new field"
+
+    # Apply migrations
+    python migrate.py --local apply
+
+    # Show next revision ID
+    python migrate.py next
+
+    # Reset after deleting migrations (clears alembic_version table)
+    python migrate.py --local reset
+
+    # Override auto-increment with custom revision ID
+    python migrate.py --local generate "initial_models" --rev-id custom_id
+
+    # Generate empty migration template without database (no autogenerate)
+    python migrate.py generate "Add performance indexes" --offline
+
+    # Inside Docker (without --local flag):
+    python migrate.py auto "Add new field"
 """
 import argparse
+import os
 import subprocess
 import sys
 from pathlib import Path
@@ -13,15 +37,21 @@ project_root = Path(__file__).resolve().parent
 if str(project_root) not in sys.path:
     sys.path.append(str(project_root))
 
-try:
-    # Import settings to check if configuration is working
-    from app.core.config import settings
 
-    print(f"Using database URL: {settings.database_url}")
-except ImportError as e:
-    print(f"Error importing settings: {e}")
-    print("Make sure your Python path includes the project root.")
-    sys.exit(1)
+def setup_database_url(use_local: bool) -> str:
+    """Setup database URL, optionally using localhost for local development."""
+    if use_local:
+        # Override DATABASE_URL to use localhost instead of Docker hostname
+        local_url = os.environ.get(
+            "LOCAL_DATABASE_URL",
+            "postgresql://postgres:postgres@localhost:5432/app"
+        )
+        os.environ["DATABASE_URL"] = local_url
+        return local_url
+
+    # Use the configured DATABASE_URL from environment/.env
+    from app.core.config import settings
+    return settings.database_url
 
 
 def check_models():
@@ -40,11 +70,30 @@ def check_models():
         return False
 
 
-def generate_migration(message):
-    """Generate an Alembic migration with the given message"""
+def generate_migration(message, rev_id=None, auto_rev_id=True, offline=False):
+    """Generate an Alembic migration with the given message.
+
+    Args:
+        message: Migration message
+        rev_id: Custom revision ID (overrides auto_rev_id)
+        auto_rev_id: If True and rev_id is None, auto-generate sequential ID
+        offline: If True, generate empty migration without database (no autogenerate)
+    """
+    # Auto-generate sequential revision ID if not provided
+    if rev_id is None and auto_rev_id:
+        rev_id = get_next_rev_id()
+
     print(f"Generating migration: {message}")
+    if rev_id:
+        print(f"Using revision ID: {rev_id}")
+
+    if offline:
+        # Generate migration file directly without database connection
+        return generate_offline_migration(message, rev_id)
 
     cmd = ["alembic", "revision", "--autogenerate", "-m", message]
+    if rev_id:
+        cmd.extend(["--rev-id", rev_id])
     result = subprocess.run(cmd, capture_output=True, text=True)
 
     print(result.stdout)
@@ -64,8 +113,9 @@ def generate_migration(message):
                     if len(part) >= 12 and all(c in "0123456789abcdef" for c in part[:12]):
                         revision = part[:12]
                         break
-            except Exception:
-                pass
+            except Exception as e:
+                # If parsing fails, we can still proceed without a detected revision
+                print(f"Warning: could not parse revision from line '{line}': {e}")
 
     if revision:
         print(f"Generated revision: {revision}")
@@ -131,8 +181,14 @@ def check_database_connection():
     from sqlalchemy.exc import SQLAlchemyError
 
     try:
-        engine = create_engine(settings.database_url)
-        with engine.connect() as conn:
+        # Use DATABASE_URL from environment (set by setup_database_url)
+        db_url = os.environ.get("DATABASE_URL")
+        if not db_url:
+            from app.core.config import settings
+            db_url = settings.database_url
+
+        engine = create_engine(db_url)
+        with engine.connect():
             print("✓ Database connection successful!")
         return True
     except SQLAlchemyError as e:
@@ -140,16 +196,172 @@ def check_database_connection():
         return False
 
 
+def get_next_rev_id():
+    """Get the next sequential revision ID based on existing migrations."""
+    import re
+
+    versions_dir = project_root / "app" / "alembic" / "versions"
+    if not versions_dir.exists():
+        return "0001"
+
+    # Find all migration files with numeric prefixes
+    max_num = 0
+    pattern = re.compile(r"^(\d{4})_.*\.py$")
+
+    for f in versions_dir.iterdir():
+        if f.is_file() and f.suffix == ".py":
+            match = pattern.match(f.name)
+            if match:
+                num = int(match.group(1))
+                max_num = max(max_num, num)
+
+    next_num = max_num + 1
+    return f"{next_num:04d}"
+
+
+def get_current_rev_id():
+    """Get the current (latest) revision ID from existing migrations."""
+    import re
+
+    versions_dir = project_root / "app" / "alembic" / "versions"
+    if not versions_dir.exists():
+        return None
+
+    # Find all migration files with numeric prefixes and get the highest
+    max_num = 0
+    max_rev_id = None
+    pattern = re.compile(r"^(\d{4})_.*\.py$")
+
+    for f in versions_dir.iterdir():
+        if f.is_file() and f.suffix == ".py":
+            match = pattern.match(f.name)
+            if match:
+                num = int(match.group(1))
+                if num > max_num:
+                    max_num = num
+                    max_rev_id = match.group(1)
+
+    return max_rev_id
+
+
+def generate_offline_migration(message, rev_id):
+    """Generate a migration file without database connection.
+
+    Creates an empty migration template that can be filled in manually.
+    Useful for performance indexes or when database is not available.
+    """
+    from datetime import datetime
+
+    versions_dir = project_root / "app" / "alembic" / "versions"
+    versions_dir.mkdir(parents=True, exist_ok=True)
+
+    # Slugify the message for filename
+    slug = message.lower().replace(" ", "_").replace("-", "_")
+    slug = "".join(c for c in slug if c.isalnum() or c == "_")
+
+    filename = f"{rev_id}_{slug}.py"
+    filepath = versions_dir / filename
+
+    # Get the previous revision ID
+    down_revision = get_current_rev_id()
+    down_rev_str = f'"{down_revision}"' if down_revision else "None"
+
+    # Generate the migration file content
+    content = f'''"""{message}
+
+Revision ID: {rev_id}
+Revises: {down_revision or ''}
+Create Date: {datetime.now().strftime('%Y-%m-%d %H:%M:%S.%f')}
+
+"""
+
+from collections.abc import Sequence
+
+import sqlalchemy as sa
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision: str = "{rev_id}"
+down_revision: str | None = {down_rev_str}
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
+
+
+def upgrade() -> None:
+    # TODO: Add your upgrade operations here
+    pass
+
+
+def downgrade() -> None:
+    # TODO: Add your downgrade operations here
+    pass
+'''
+
+    filepath.write_text(content)
+    print(f"Generated offline migration: {filepath}")
+    return rev_id
+
+
+def show_next_rev_id():
+    """Show the next sequential revision ID."""
+    next_id = get_next_rev_id()
+    print(f"Next revision ID: {next_id}")
+    print(f"\nUsage:")
+    print(f"  python migrate.py --local generate 'your_message' --rev-id {next_id}")
+    print(f"  python migrate.py --local auto 'your_message' --rev-id {next_id}")
+    return next_id
+
+
+def reset_alembic_version():
+    """Reset the alembic_version table (for fresh start after deleting migrations)."""
+    from sqlalchemy import create_engine, text
+    from sqlalchemy.exc import SQLAlchemyError
+
+    db_url = os.environ.get("DATABASE_URL")
+    if not db_url:
+        from app.core.config import settings
+        db_url = settings.database_url
+
+    try:
+        engine = create_engine(db_url)
+        with engine.connect() as conn:
+            conn.execute(text("DROP TABLE IF EXISTS alembic_version"))
+            conn.commit()
+        print("✓ Alembic version table reset successfully")
+        print("  You can now run migrations from scratch")
+        return True
+    except SQLAlchemyError as e:
+        print(f"✗ Error resetting alembic version: {e}")
+        return False
+
+
 def main():
     """Main function"""
     parser = argparse.ArgumentParser(
-        description='Database migration helper for PragmaStack template'
+        description='Database migration helper for Generative Models Arena'
     )
+
+    # Global options
+    parser.add_argument(
+        '--local', '-l',
+        action='store_true',
+        help='Use localhost instead of Docker hostname (for local development)'
+    )
+
     subparsers = parser.add_subparsers(dest='command', help='Command to run')
 
     # Generate command
     generate_parser = subparsers.add_parser('generate', help='Generate a migration')
     generate_parser.add_argument('message', help='Migration message')
+    generate_parser.add_argument(
+        '--rev-id',
+        help='Custom revision ID (e.g., 0001, 0002 for sequential naming)'
+    )
+    generate_parser.add_argument(
+        '--offline',
+        action='store_true',
+        help='Generate empty migration template without database connection'
+    )
 
     # Apply command
     apply_parser = subparsers.add_parser('apply', help='Apply migrations')
@@ -164,15 +376,56 @@ def main():
     # Check command
     subparsers.add_parser('check', help='Check database connection and models')
 
+    # Next command (show next revision ID)
+    subparsers.add_parser('next', help='Show the next sequential revision ID')
+
+    # Reset command (clear alembic_version table)
+    subparsers.add_parser(
+        'reset',
+        help='Reset alembic_version table (use after deleting all migrations)'
+    )
+
     # Auto command (generate and apply)
     auto_parser = subparsers.add_parser('auto', help='Generate and apply migration')
     auto_parser.add_argument('message', help='Migration message')
+    auto_parser.add_argument(
+        '--rev-id',
+        help='Custom revision ID (e.g., 0001, 0002 for sequential naming)'
+    )
+    auto_parser.add_argument(
+        '--offline',
+        action='store_true',
+        help='Generate empty migration template without database connection'
+    )
 
     args = parser.parse_args()
 
+    # Commands that don't need database connection
+    if args.command == 'next':
+        show_next_rev_id()
+        return
+
+    # Check if offline mode is requested
+    offline = getattr(args, 'offline', False)
+
+    # Offline generate doesn't need database or model check
+    if args.command == 'generate' and offline:
+        generate_migration(args.message, rev_id=args.rev_id, offline=True)
+        return
+
+    if args.command == 'auto' and offline:
+        generate_migration(args.message, rev_id=args.rev_id, offline=True)
+        print("\nOffline migration generated. Apply it later with:")
+        print(f"  python migrate.py --local apply")
+        return
+
+    # Setup database URL (must be done before importing settings elsewhere)
+    db_url = setup_database_url(args.local)
+    print(f"Using database URL: {db_url}")
+
     if args.command == 'generate':
         check_models()
-        generate_migration(args.message)
+        generate_migration(args.message, rev_id=args.rev_id)
 
     elif args.command == 'apply':
         apply_migration(args.revision)
@@ -187,11 +440,14 @@ def main():
         check_database_connection()
         check_models()
 
+    elif args.command == 'reset':
+        reset_alembic_version()
+
     elif args.command == 'auto':
         check_models()
-        revision = generate_migration(args.message)
+        revision = generate_migration(args.message, rev_id=args.rev_id)
         if revision:
-            proceed = input("\nPress Enter to apply migration or Ctrl+C to abort... ")
+            input("\nPress Enter to apply migration or Ctrl+C to abort... ")
             apply_migration()
 
     else:

backend/pyproject.toml

@@ -20,40 +20,36 @@ dependencies = [
     "uvicorn>=0.34.0",
     "pydantic>=2.10.6",
     "pydantic-settings>=2.2.1",
-    "python-multipart>=0.0.19",
+    "python-multipart>=0.0.22",
     "fastapi-utils==0.8.0",
-
     # Database
     "sqlalchemy>=2.0.29",
     "alembic>=1.14.1",
     "psycopg2-binary>=2.9.9",
     "asyncpg>=0.29.0",
     "aiosqlite==0.21.0",
-
     # Environment configuration
     "python-dotenv>=1.0.1",
-
     # API utilities
     "email-validator>=2.1.0.post1",
     "ujson>=5.9.0",
-
     # CORS and security
     "starlette>=0.40.0",
     "starlette-csrf>=1.4.5",
     "slowapi>=0.1.9",
-
     # Utilities
     "httpx>=0.27.0",
     "tenacity>=8.2.3",
     "pytz>=2024.1",
-    "pillow>=10.3.0",
+    "pillow>=12.1.1",
     "apscheduler==3.11.0",
-
-    # Security and authentication (pinned for reproducibility)
-    "python-jose==3.4.0",
-    "passlib==1.7.4",
+    # Security and authentication
+    "PyJWT>=2.9.0",
     "bcrypt==4.2.1",
-    "cryptography==44.0.1",
+    "cryptography>=46.0.5",
+    # OAuth authentication
+    "authlib>=1.6.6",
+    "urllib3>=2.6.3",
 ]
 
 # Development dependencies
@@ -69,7 +65,24 @@ dev = [
 
     # Development tools
     "ruff>=0.8.0",  # All-in-one: linting, formatting, import sorting
-    "mypy>=1.8.0",  # Type checking
+    "pyright>=1.1.390",  # Type checking
+
+    # Security auditing
+    "pip-audit>=2.7.0",  # Dependency vulnerability scanning (PyPA/OSV)
+    "pip-licenses>=4.0.0",  # License compliance checking
+    "detect-secrets>=1.5.0",  # Hardcoded secrets detection
+
+    # Performance benchmarking
+    "pytest-benchmark>=4.0.0",  # Performance regression detection
+
+    # Pre-commit hooks
+    "pre-commit>=4.0.0",  # Git pre-commit hook framework
+]
+
+# E2E testing with real PostgreSQL (requires Docker)
+e2e = [
+    "testcontainers[postgres]>=4.0.0",
+    "schemathesis>=3.30.0",
 ]
 
 # ============================================================================
@@ -122,6 +135,8 @@ select = [
     "RUF",    # Ruff-specific
     "ASYNC",  # flake8-async
     "S",      # flake8-bandit (security)
+    "G",      # flake8-logging-format (logging best practices)
+    "T20",    # flake8-print (no print statements in production code)
 ]
 
 # Ignore specific rules
@@ -145,11 +160,13 @@ unfixable = []
 [tool.ruff.lint.per-file-ignores]
 "app/alembic/env.py" = ["E402", "F403", "F405"]  # Alembic requires specific import order
 "app/alembic/versions/*.py" = ["E402"]  # Migration files have specific structure
-"tests/**/*.py" = ["S101", "N806", "B017", "N817", "S110", "ASYNC251", "RUF043"]  # pytest: asserts, CamelCase fixtures, blind exceptions, try-pass patterns, and async test helpers are intentional
+"tests/**/*.py" = ["S101", "N806", "B017", "N817", "ASYNC251", "RUF043", "T20"]  # pytest: asserts, CamelCase fixtures, blind exceptions, async test helpers, and print for debugging are intentional
 "app/models/__init__.py" = ["F401"]  # __init__ files re-export modules
 "app/models/base.py" = ["F401"]  # Re-exports Base for use by other models
 "app/utils/test_utils.py" = ["N806"]  # SQLAlchemy session factories use CamelCase convention
 "app/main.py" = ["N806"]  # Constants use UPPER_CASE convention
+"app/init_db.py" = ["T20"]  # CLI script uses print for user-facing output
+"migrate.py" = ["T20"]  # CLI script uses print for user-facing output
 
 # ============================================================================
 # Ruff Import Sorting (isort replacement)
@@ -176,116 +193,6 @@ indent-style = "space"
 skip-magic-trailing-comma = false
 line-ending = "lf"
 
-# ============================================================================
-# mypy Configuration - Type Checking
-# ============================================================================
-[tool.mypy]
-python_version = "3.12"
-warn_return_any = false  # SQLAlchemy queries return Any - overly strict
-warn_unused_configs = true
-disallow_untyped_defs = false  # Gradual typing - enable later
-disallow_incomplete_defs = false
-check_untyped_defs = true
-no_implicit_optional = true
-warn_redundant_casts = true
-warn_unused_ignores = true
-warn_no_return = true
-strict_equality = true
-ignore_missing_imports = false
-explicit_package_bases = true
-namespace_packages = true
-
-# Pydantic plugin for better validation
-plugins = ["pydantic.mypy"]
-
-# Per-module options
-[[tool.mypy.overrides]]
-module = "alembic.*"
-ignore_errors = true
-
-[[tool.mypy.overrides]]
-module = "app.alembic.*"
-ignore_errors = true
-
-[[tool.mypy.overrides]]
-module = "sqlalchemy.*"
-ignore_missing_imports = true
-
-[[tool.mypy.overrides]]
-module = "fastapi_utils.*"
-ignore_missing_imports = true
-
-[[tool.mypy.overrides]]
-module = "slowapi.*"
-ignore_missing_imports = true
-
-[[tool.mypy.overrides]]
-module = "jose.*"
-ignore_missing_imports = true
-
-[[tool.mypy.overrides]]
-module = "passlib.*"
-ignore_missing_imports = true
-
-[[tool.mypy.overrides]]
-module = "pydantic_settings.*"
-ignore_missing_imports = true
-
-[[tool.mypy.overrides]]
-module = "fastapi.*"
-ignore_missing_imports = true
-
-[[tool.mypy.overrides]]
-module = "apscheduler.*"
-ignore_missing_imports = true
-
-[[tool.mypy.overrides]]
-module = "starlette.*"
-ignore_missing_imports = true
-
-# SQLAlchemy ORM models - Column descriptors cause type confusion
-[[tool.mypy.overrides]]
-module = "app.models.*"
-disable_error_code = ["assignment", "arg-type", "return-value"]
-
-# CRUD operations - Generic ModelType and SQLAlchemy Result issues
-[[tool.mypy.overrides]]
-module = "app.crud.*"
-disable_error_code = ["attr-defined", "assignment", "arg-type", "return-value"]
-
-# API routes - SQLAlchemy Column to Pydantic schema conversions
-[[tool.mypy.overrides]]
-module = "app.api.routes.*"
-disable_error_code = ["arg-type", "call-arg", "call-overload", "assignment"]
-
-# API dependencies - Similar SQLAlchemy Column issues
-[[tool.mypy.overrides]]
-module = "app.api.dependencies.*"
-disable_error_code = ["arg-type"]
-
-# FastAPI exception handlers have correct signatures despite mypy warnings
-[[tool.mypy.overrides]]
-module = "app.main"
-disable_error_code = ["arg-type"]
-
-# Auth service - SQLAlchemy Column issues
-[[tool.mypy.overrides]]
-module = "app.services.auth_service"
-disable_error_code = ["assignment", "arg-type"]
-
-# Test utils - Testing patterns
-[[tool.mypy.overrides]]
-module = "app.utils.auth_test_utils"
-disable_error_code = ["assignment", "arg-type"]
-
-# ============================================================================
-# Pydantic mypy plugin configuration
-# ============================================================================
-[tool.pydantic-mypy]
-init_forbid_extra = true
-init_typed = true
-warn_required_dynamic_aliases = true
-
 # ============================================================================
 # Pytest Configuration
 # ============================================================================
@@ -302,10 +209,15 @@ addopts = [
     "--cov=app",
     "--cov-report=term-missing",
     "--cov-report=html",
+    "--ignore=tests/benchmarks",  # benchmarks are incompatible with xdist; run via 'make benchmark'
+    "-p", "no:benchmark",  # disable pytest-benchmark plugin during normal runs (conflicts with xdist)
 ]
 markers = [
     "sqlite: marks tests that should run on SQLite (mocked).",
     "postgres: marks tests that require a real PostgreSQL database.",
+    "e2e: marks end-to-end tests requiring Docker containers.",
+    "schemathesis: marks Schemathesis-generated API tests.",
+    "benchmark: marks performance benchmark tests.",
 ]
 asyncio_default_fixture_loop_scope = "function"
 
@@ -319,6 +231,7 @@ omit = [
     "*/__pycache__/*",
     "*/alembic/versions/*",
     "*/.venv/*",
+    "app/init_db.py",  # CLI script for database initialization
 ]
 branch = true
 

backend/pyrightconfig.json

@@ -0,0 +1,23 @@
+{
+  "include": ["app"],
+  "exclude": ["app/alembic"],
+  "pythonVersion": "3.12",
+  "venvPath": ".",
+  "venv": ".venv",
+  "typeCheckingMode": "standard",
+  "reportMissingImports": true,
+  "reportMissingTypeStubs": false,
+  "reportUnknownMemberType": false,
+  "reportUnknownVariableType": false,
+  "reportUnknownArgumentType": false,
+  "reportUnknownParameterType": false,
+  "reportUnknownLambdaType": false,
+  "reportReturnType": true,
+  "reportUnusedImport": false,
+  "reportGeneralTypeIssues": false,
+  "reportAttributeAccessIssue": false,
+  "reportArgumentType": false,
+  "strictListInference": false,
+  "strictDictionaryInference": false,
+  "strictSetInference": false
+}

backend/tests/api/test_admin.py

@@ -147,7 +147,7 @@ class TestAdminCreateUser:
             headers={"Authorization": f"Bearer {superuser_token}"},
         )
 
-        assert response.status_code == status.HTTP_404_NOT_FOUND
+        assert response.status_code == status.HTTP_409_CONFLICT
 
 
 class TestAdminGetUser:
@@ -565,7 +565,7 @@ class TestAdminCreateOrganization:
             headers={"Authorization": f"Bearer {superuser_token}"},
         )
 
-        assert response.status_code == status.HTTP_404_NOT_FOUND
+        assert response.status_code == status.HTTP_409_CONFLICT
 
 
 class TestAdminGetOrganization:
@@ -923,6 +923,27 @@ class TestAdminRemoveOrganizationMember:
 
         assert response.status_code == status.HTTP_404_NOT_FOUND
 
+    @pytest.mark.asyncio
+    async def test_admin_remove_organization_member_user_not_found(
+        self, client, async_test_superuser, async_test_db, superuser_token
+    ):
+        """Test removing non-existent user from organization."""
+        _test_engine, AsyncTestingSessionLocal = async_test_db
+
+        # Create organization
+        async with AsyncTestingSessionLocal() as session:
+            org = Organization(name="User Not Found Org", slug="user-not-found-org")
+            session.add(org)
+            await session.commit()
+            org_id = org.id
+
+        response = await client.delete(
+            f"/api/v1/admin/organizations/{org_id}/members/{uuid4()}",
+            headers={"Authorization": f"Bearer {superuser_token}"},
+        )
+
+        assert response.status_code == status.HTTP_404_NOT_FOUND
+
 
 # ===== SESSION MANAGEMENT TESTS =====
 
@@ -1097,3 +1118,102 @@ class TestAdminListSessions:
         )
 
         assert response.status_code == status.HTTP_403_FORBIDDEN
+
+
+# ===== ADMIN STATS TESTS =====
+
+
+class TestAdminStats:
+    """Tests for GET /admin/stats endpoint."""
+
+    @pytest.mark.asyncio
+    async def test_admin_get_stats_with_data(
+        self,
+        client,
+        async_test_superuser,
+        async_test_user,
+        async_test_db,
+        superuser_token,
+    ):
+        """Test getting admin stats with real data in database."""
+        _test_engine, AsyncTestingSessionLocal = async_test_db
+
+        # Create multiple users and organizations with members
+        async with AsyncTestingSessionLocal() as session:
+            from app.core.auth import get_password_hash
+            from app.models.user import User
+
+            # Create several users
+            for i in range(5):
+                user = User(
+                    email=f"statsuser{i}@example.com",
+                    password_hash=get_password_hash("TestPassword123!"),
+                    first_name=f"Stats{i}",
+                    last_name="User",
+                    is_active=i % 2 == 0,  # Mix of active/inactive
+                )
+                session.add(user)
+            await session.commit()
+
+        # Create organizations with members
+        async with AsyncTestingSessionLocal() as session:
+            orgs = []
+            for i in range(3):
+                org = Organization(name=f"Stats Org {i}", slug=f"stats-org-{i}")
+                session.add(org)
+                orgs.append(org)
+            await session.flush()
+
+            # Add some members to organizations
+            user_org = UserOrganization(
+                user_id=async_test_user.id,
+                organization_id=orgs[0].id,
+                role=OrganizationRole.MEMBER,
+                is_active=True,
+            )
+            session.add(user_org)
+            await session.commit()
+
+        response = await client.get(
+            "/api/v1/admin/stats",
+            headers={"Authorization": f"Bearer {superuser_token}"},
+        )
+
+        assert response.status_code == status.HTTP_200_OK
+        data = response.json()
+
+        # Verify response structure
+        assert "user_growth" in data
+        assert "organization_distribution" in data
+        assert "registration_activity" in data
+        assert "user_status" in data
+
+        # Verify user_growth has 30 days of data
+        assert len(data["user_growth"]) == 30
+        for item in data["user_growth"]:
+            assert "date" in item
+            assert "total_users" in item
+            assert "active_users" in item
+
+        # Verify registration_activity has 14 days of data
+        assert len(data["registration_activity"]) == 14
+        for item in data["registration_activity"]:
+            assert "date" in item
+            assert "registrations" in item
+
+        # Verify user_status has active/inactive counts
+        assert len(data["user_status"]) == 2
+        status_names = {item["name"] for item in data["user_status"]}
+        assert status_names == {"Active", "Inactive"}
+
+    @pytest.mark.asyncio
+    async def test_admin_get_stats_unauthorized(
+        self, client, async_test_user, user_token
+    ):
+        """Test that non-admin users cannot access stats endpoint."""
+        response = await client.get(
+            "/api/v1/admin/stats",
+            headers={"Authorization": f"Bearer {user_token}"},
+        )
+
+        assert response.status_code == status.HTTP_403_FORBIDDEN

backend/tests/api/test_admin_error_handlers.py

@@ -45,7 +45,7 @@ class TestAdminListUsersFilters:
     async def test_list_users_database_error_propagates(self, client, superuser_token):
         """Test that database errors propagate correctly (covers line 118-120)."""
         with patch(
-            "app.api.routes.admin.user_crud.get_multi_with_total",
+            "app.api.routes.admin.user_service.list_users",
             side_effect=Exception("DB error"),
         ):
             with pytest.raises(Exception):
@@ -74,8 +74,8 @@ class TestAdminCreateUserErrors:
             },
         )
 
-        # Should get error for duplicate email
-        assert response.status_code == status.HTTP_404_NOT_FOUND
+        # Should get conflict for duplicate email
+        assert response.status_code == status.HTTP_409_CONFLICT
 
     @pytest.mark.asyncio
     async def test_create_user_unexpected_error_propagates(
@@ -83,7 +83,7 @@ class TestAdminCreateUserErrors:
     ):
         """Test unexpected errors during user creation (covers line 151-153)."""
         with patch(
-            "app.api.routes.admin.user_crud.create",
+            "app.api.routes.admin.user_service.create_user",
             side_effect=RuntimeError("Unexpected error"),
         ):
             with pytest.raises(RuntimeError):
@@ -135,7 +135,7 @@ class TestAdminUpdateUserErrors:
     ):
         """Test unexpected errors during user update (covers line 206-208)."""
         with patch(
-            "app.api.routes.admin.user_crud.update",
+            "app.api.routes.admin.user_service.update_user",
             side_effect=RuntimeError("Update failed"),
         ):
             with pytest.raises(RuntimeError):
@@ -166,7 +166,7 @@ class TestAdminDeleteUserErrors:
     ):
         """Test unexpected errors during user deletion (covers line 238-240)."""
         with patch(
-            "app.api.routes.admin.user_crud.soft_delete",
+            "app.api.routes.admin.user_service.soft_delete_user",
             side_effect=Exception("Delete failed"),
         ):
             with pytest.raises(Exception):
@@ -196,7 +196,7 @@ class TestAdminActivateUserErrors:
     ):
         """Test unexpected errors during user activation (covers line 282-284)."""
         with patch(
-            "app.api.routes.admin.user_crud.update",
+            "app.api.routes.admin.user_service.update_user",
             side_effect=Exception("Activation failed"),
         ):
             with pytest.raises(Exception):
@@ -238,7 +238,7 @@ class TestAdminDeactivateUserErrors:
     ):
         """Test unexpected errors during user deactivation (covers line 326-328)."""
         with patch(
-            "app.api.routes.admin.user_crud.update",
+            "app.api.routes.admin.user_service.update_user",
             side_effect=Exception("Deactivation failed"),
         ):
             with pytest.raises(Exception):
@@ -258,7 +258,7 @@ class TestAdminListOrganizationsErrors:
     async def test_list_organizations_database_error(self, client, superuser_token):
         """Test list organizations with database error (covers line 427-456)."""
         with patch(
-            "app.api.routes.admin.organization_crud.get_multi_with_member_counts",
+            "app.api.routes.admin.organization_service.get_multi_with_member_counts",
             side_effect=Exception("DB error"),
         ):
             with pytest.raises(Exception):
@@ -299,14 +299,14 @@ class TestAdminCreateOrganizationErrors:
             },
         )
 
-        # Should get error for duplicate slug
-        assert response.status_code == status.HTTP_404_NOT_FOUND
+        # Should get conflict for duplicate slug
+        assert response.status_code == status.HTTP_409_CONFLICT
 
     @pytest.mark.asyncio
     async def test_create_organization_unexpected_error(self, client, superuser_token):
         """Test unexpected errors during organization creation (covers line 484-485)."""
         with patch(
-            "app.api.routes.admin.organization_crud.create",
+            "app.api.routes.admin.organization_service.create_organization",
             side_effect=RuntimeError("Creation failed"),
         ):
             with pytest.raises(RuntimeError):
@@ -367,7 +367,7 @@ class TestAdminUpdateOrganizationErrors:
             org_id = org.id
 
         with patch(
-            "app.api.routes.admin.organization_crud.update",
+            "app.api.routes.admin.organization_service.update_organization",
             side_effect=Exception("Update failed"),
         ):
             with pytest.raises(Exception):
@@ -412,7 +412,7 @@ class TestAdminDeleteOrganizationErrors:
             org_id = org.id
 
         with patch(
-            "app.api.routes.admin.organization_crud.remove",
+            "app.api.routes.admin.organization_service.remove_organization",
             side_effect=Exception("Delete failed"),
         ):
             with pytest.raises(Exception):
@@ -456,7 +456,7 @@ class TestAdminListOrganizationMembersErrors:
             org_id = org.id
 
         with patch(
-            "app.api.routes.admin.organization_crud.get_organization_members",
+            "app.api.routes.admin.organization_service.get_organization_members",
             side_effect=Exception("DB error"),
         ):
             with pytest.raises(Exception):
@@ -531,7 +531,7 @@ class TestAdminAddOrganizationMemberErrors:
             org_id = org.id
 
         with patch(
-            "app.api.routes.admin.organization_crud.add_user",
+            "app.api.routes.admin.organization_service.add_member",
             side_effect=Exception("Add failed"),
         ):
             with pytest.raises(Exception):
@@ -587,7 +587,7 @@ class TestAdminRemoveOrganizationMemberErrors:
             org_id = org.id
 
         with patch(
-            "app.api.routes.admin.organization_crud.remove_user",
+            "app.api.routes.admin.organization_service.remove_member",
             side_effect=Exception("Remove failed"),
         ):
             with pytest.raises(Exception):

backend/tests/api/test_auth_error_handlers.py

@@ -19,7 +19,7 @@ class TestLoginSessionCreationFailure:
         """Test that login succeeds even if session creation fails."""
         # Mock session creation to fail
         with patch(
-            "app.api.routes.auth.session_crud.create_session",
+            "app.api.routes.auth.session_service.create_session",
             side_effect=Exception("Session creation failed"),
         ):
             response = await client.post(
@@ -43,7 +43,7 @@ class TestOAuthLoginSessionCreationFailure:
     ):
         """Test OAuth login succeeds even if session creation fails."""
         with patch(
-            "app.api.routes.auth.session_crud.create_session",
+            "app.api.routes.auth.session_service.create_session",
             side_effect=Exception("Session failed"),
         ):
             response = await client.post(
@@ -76,7 +76,7 @@ class TestRefreshTokenSessionUpdateFailure:
 
         # Mock session update to fail
         with patch(
-            "app.api.routes.auth.session_crud.update_refresh_token",
+            "app.api.routes.auth.session_service.update_refresh_token",
             side_effect=Exception("Update failed"),
         ):
             response = await client.post(
@@ -130,7 +130,7 @@ class TestLogoutWithNonExistentSession:
         tokens = response.json()
 
         # Mock session lookup to return None
-        with patch("app.api.routes.auth.session_crud.get_by_jti", return_value=None):
+        with patch("app.api.routes.auth.session_service.get_by_jti", return_value=None):
             response = await client.post(
                 "/api/v1/auth/logout",
                 headers={"Authorization": f"Bearer {tokens['access_token']}"},
@@ -157,7 +157,7 @@ class TestLogoutUnexpectedError:
 
         # Mock to raise unexpected error
         with patch(
-            "app.api.routes.auth.session_crud.get_by_jti",
+            "app.api.routes.auth.session_service.get_by_jti",
             side_effect=Exception("Unexpected error"),
         ):
             response = await client.post(
@@ -186,7 +186,7 @@ class TestLogoutAllUnexpectedError:
 
         # Mock to raise database error
         with patch(
-            "app.api.routes.auth.session_crud.deactivate_all_user_sessions",
+            "app.api.routes.auth.session_service.deactivate_all_user_sessions",
             side_effect=Exception("DB error"),
         ):
             response = await client.post(
@@ -212,7 +212,7 @@ class TestPasswordResetConfirmSessionInvalidation:
 
         # Mock session invalidation to fail
         with patch(
-            "app.api.routes.auth.session_crud.deactivate_all_user_sessions",
+            "app.api.routes.auth.session_service.deactivate_all_user_sessions",
             side_effect=Exception("Invalidation failed"),
         ):
             response = await client.post(