FastAPI combines Python type hints with Pydantic for validated, documented APIs. Async support enables high concurrency. Automatic OpenAPI documentation. Dependency injection simplifies testing.
API Definition
Define endpoints with decorators. Pydantic models validate input. Type hints specify response shapes. Async functions handle concurrent requests.
- Use Pydantic models for request/response validation
- Leverage type hints for automatic documentation
- Implement async endpoints for I/O-bound work
- Use dependency injection for shared resources
- Access automatic OpenAPI docs at /docs
Performance
Starlette foundation provides async performance. Uvicorn or Gunicorn for production serving. Comparable to Node.js and Go for I/O workloads.