syndarix/backend/app/tasks/cost.py

# app/tasks/cost.py
"""
Cost tracking and budget management tasks for Syndarix.

These tasks implement multi-layered cost tracking per ADR-012:
- Per-agent token usage tracking
- Project budget monitoring
- Daily cost aggregation
- Budget threshold alerts
- Cost reporting

Costs are tracked in real-time in Redis for speed,
then aggregated to PostgreSQL for durability.
"""

import logging
from typing import Any

from app.celery_app import celery_app

logger = logging.getLogger(__name__)


@celery_app.task(bind=True, name="app.tasks.cost.aggregate_daily_costs")
def aggregate_daily_costs(self) -> dict[str, Any]:
    """
    Aggregate daily costs from Redis to PostgreSQL.

    This periodic task (runs daily):
    1. Read accumulated costs from Redis
    2. Aggregate by project, agent, and model
    3. Store in PostgreSQL cost_records table
    4. Clear Redis counters for new day

    Returns:
        dict with status
    """
    logger.info("Starting daily cost aggregation")

    # TODO: Implement cost aggregation
    # This will involve:
    # 1. Fetching cost data from Redis
    # 2. Grouping by project_id, agent_id, model
    # 3. Inserting into PostgreSQL cost tables
    # 4. Resetting Redis counters

    return {
        "status": "pending",
    }


@celery_app.task(bind=True, name="app.tasks.cost.check_budget_thresholds")
def check_budget_thresholds(
    self,
    project_id: str,
) -> dict[str, Any]:
    """
    Check if a project has exceeded budget thresholds.

    This task checks budget limits:
    1. Get current spend from Redis counters
    2. Compare against project budget limits
    3. Send alerts if thresholds exceeded
    4. Pause agents if hard limit reached

    Args:
        project_id: UUID of the project

    Returns:
        dict with status and project_id
    """
    logger.info(f"Checking budget thresholds for project {project_id}")

    # TODO: Implement budget checking
    # This will involve:
    # 1. Loading project budget configuration
    # 2. Getting current spend from Redis
    # 3. Comparing against soft/hard limits
    # 4. Sending alerts or pausing agents

    return {
        "status": "pending",
        "project_id": project_id,
    }


@celery_app.task(bind=True, name="app.tasks.cost.record_llm_usage")
def record_llm_usage(
    self,
    agent_id: str,
    project_id: str,
    model: str,
    prompt_tokens: int,
    completion_tokens: int,
    cost_usd: float,
) -> dict[str, Any]:
    """
    Record LLM usage from an agent call.

    This task tracks each LLM API call:
    1. Increment Redis counters for real-time tracking
    2. Store raw usage event for audit
    3. Trigger budget check if threshold approaching

    Args:
        agent_id: UUID of the agent instance
        project_id: UUID of the project
        model: Model identifier (e.g., claude-opus-4-5-20251101)
        prompt_tokens: Number of input tokens
        completion_tokens: Number of output tokens
        cost_usd: Calculated cost in USD

    Returns:
        dict with status, agent_id, project_id, and cost_usd
    """
    logger.debug(
        f"Recording LLM usage for model {model}: "
        f"{prompt_tokens} prompt + {completion_tokens} completion tokens = ${cost_usd}"
    )

    # TODO: Implement usage recording
    # This will involve:
    # 1. Incrementing Redis counters
    # 2. Storing usage event
    # 3. Checking if near budget threshold

    return {
        "status": "pending",
        "agent_id": agent_id,
        "project_id": project_id,
        "cost_usd": cost_usd,
    }


@celery_app.task(bind=True, name="app.tasks.cost.generate_cost_report")
def generate_cost_report(
    self,
    project_id: str,
    start_date: str,
    end_date: str,
) -> dict[str, Any]:
    """
    Generate a cost report for a project.

    This task creates a detailed cost breakdown:
    1. Query cost records for date range
    2. Group by agent, model, and day
    3. Calculate totals and trends
    4. Format report for display

    Args:
        project_id: UUID of the project
        start_date: Report start date (YYYY-MM-DD)
        end_date: Report end date (YYYY-MM-DD)

    Returns:
        dict with status, project_id, and date range
    """
    logger.info(
        f"Generating cost report for project {project_id} from {start_date} to {end_date}"
    )

    # TODO: Implement report generation
    # This will involve:
    # 1. Querying PostgreSQL for cost records
    # 2. Aggregating by various dimensions
    # 3. Calculating totals and averages
    # 4. Formatting report data

    return {
        "status": "pending",
        "project_id": project_id,
        "start_date": start_date,
        "end_date": end_date,
    }


@celery_app.task(bind=True, name="app.tasks.cost.reset_daily_budget_counters")
def reset_daily_budget_counters(self) -> dict[str, Any]:
    """
    Reset daily budget counters in Redis.

    This periodic task (runs daily at midnight UTC):
    1. Archive current day's counters
    2. Reset all daily budget counters
    3. Prepare for new day's tracking

    Returns:
        dict with status
    """
    logger.info("Resetting daily budget counters")

    # TODO: Implement counter reset
    # This will involve:
    # 1. Getting all daily counter keys from Redis
    # 2. Archiving current values
    # 3. Resetting counters to zero

    return {
        "status": "pending",
    }