Starlette
Lightweight ASGI framework that powers FastAPI — ideal for building high-performance async web services, WebSockets, and background tasks
Visit Starlette →Starlette is the ASGI toolkit FastAPI is built on top of — routing, middleware, request/response objects, WebSocket support, and background tasks, without FastAPI’s request-validation and auto-documentation layer on top.
You can use Starlette directly for a lightweight async service that doesn’t need FastAPI’s Pydantic-driven validation — see What Is Uvicorn? for how Starlette, FastAPI, and the ASGI server underneath all fit together.