# API Documentation Specification

## Purpose

Provide comprehensive API documentation and health monitoring endpoints.

## Requirements

### Requirement: OpenAPI/Swagger Documentation

The system SHALL auto-generate API documentation.

#### Scenario: API docs access
- GIVEN the running API server
- WHEN visiting `/docs`
- THEN Swagger UI displays:
  - All available endpoints
  - Request/response schemas
  - Authentication requirements
  - Example requests and responses

### Requirement: Health Check Endpoints

The system SHALL provide health monitoring endpoints.

#### Scenario: General health check
- GIVEN the running API server
- WHEN visiting `/health`
- THEN it returns:
  - Overall service status
  - Database connectivity status
  - Redis connectivity status
  - Disk space status
  - Uptime information

#### Scenario: Database health check
- GIVEN the running API server
- WHEN visiting `/health/db`
- THEN it returns:
  - Database connection status
  - Response time
  - Connection pool status

### Requirement: API Setup Documentation

The system SHALL document API setup and configuration.

#### Scenario: Developer onboarding
- GIVEN a new developer
- WHEN they read `apps/api/README.md`
- THEN they find:
  - Setup instructions
  - Environment variables
  - Running tests
  - Common commands
  - Architecture overview

### Requirement: Architecture Decision Records

The system SHALL document significant architectural decisions.

#### Scenario: Auth decision record
- GIVEN the codebase
- THEN an ADR SHALL exist documenting:
  - Why httpOnly cookies were chosen
  - Alternatives considered
  - Trade-offs and risks
  - Decision date and participants

### Requirement: Endpoint Documentation

The system SHALL document all API endpoints.

#### Scenario: Endpoint coverage
- GIVEN the API codebase
- THEN every endpoint SHALL have:
  - Pydantic request/response models
  - Docstrings with descriptions
  - Response status codes
  - Authentication requirements

## Dependencies

- FastAPI (auto-generates OpenAPI)
- Pydantic v2

## Quality Gates

- `/docs` endpoint loads successfully
- `/health` returns 200 with valid JSON
- `/health/db` returns database status
- `pytest` must pass
- `mypy .` must pass
- `ruff check .` must pass
