FastAPI Patterns

Modern Python API development with FastAPI, Pydantic v2, and async/await.

When to Activate

• Building or reviewing FastAPI API endpoints
• Designing Pydantic request/response schemas
• Implementing dependency injection with Depends()
• Writing async database queries (SQLAlchemy async, Motor)
• Setting up FastAPI testing with pytest + HTTPX
• Structuring a FastAPI project (routers, services, repositories)
• Migrating a Flask or Django REST Framework app to FastAPI
• Adding background tasks or lifespan event handlers to an existing FastAPI application
• Configuring global exception handlers to return RFC 7807 Problem Details responses

Project Structure