WebSocket support is now available for Python Functions

Vercel now supports WebSocket connections for Python applications.

WebSockets enable bidirectional communication between client- and server-side code, powering real-time features like interactive AI streaming, real-time chat, and multiplayer live collaboration. Both ASGI and WSGI applications are supported, including frameworks like FastAPI, Django, and Flask.

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import fastapi
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app = fastapi.FastAPI()
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@app.websocket("/api/ws")
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async def websocket_endpoint(websocket: fastapi.WebSocket):
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    await websocket.accept()
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    try:
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        while True:
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            message = await websocket.receive_text()
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            await websocket.send_text(message)
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    except fastapi.WebSocketDisconnect:
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        pass

Explore the FastAPI AI Chat and Flask AI Chat examples, or read the WebSockets documentation to get started.