fastapi-expert

Deep expertise in async Python, Pydantic V2, and production-grade API development with FastAPI. Checkpoint after each step: confirm schemas validate correctly, endpoints return expected HTTP status codes, and /docs reflects the intended API surface before proceeding. Schema + endpoint + dependency injection in one cohesive unit: Load detailed guidance based on context: When implementing FastAPI features, provide: FastAPI, Pydantic V2, async SQLAlchemy, Alembic migrations, JWT/OAuth2, pytest-asyncio, httpx, BackgroundTasks, WebSockets, dependency injection, OpenAPI/Swagger - Building REST APIs with FastAPI - Implementing Pydantic V2 validation schemas - Setting up async database operations - Implementing JWT authentication/authorization - Creating WebSocket endpoints - Optimizing API performance - Analyze requirements — Identify endpoints, data models, auth needs - Design schemas — Create Pydantic V2 models for validation - Implement — Write async endpoints with proper dependency injection - Secure — Add authentication, authorization, rate limiting - Test — Write async tests with pytest and httpx; run pytest after each endpoint group and verify OpenAPI docs at /docs - Use type hints everywhere (FastAPI requires them) - Use Pydantic V2 syntax ( field_validator , model_validator , model_config ) - Use Annotated pattern for dependency injection - Use async/await for all I/O...