FastAPI, AsgiFunctionApp and WebSockets

[Michel Hua (mycaule)]

Hi,

I am trying to write a FastAPI websocket endpoint just like in their tutorial, I can successfully run it with fastapi dev app.py on localhost:8000.

$ curl localhost:8000/chat
✅

$ websocat ws://localhost:8000/chat/ws/1721224068746
✅

Now, when I mount the FastAPI app using AsgiFunctionApp and func start, there is a new http_app_func on localhost:7071.

http_app_func: [GET,POST,DELETE,HEAD,PATCH,PUT,OPTIONS] http://localhost:7071/api/{*route}

But the same CLI test is not working,

$ curl localhost:7071/api/chat
✅

$ websocat ws://localhost:7071/api/chat/ws/1721224068746
❌
websocat: WebSocketError: WebSocketError: Received unexpected status code (404 Not Found)
websocat: error running

How can I change the implementation of AsgiFunctionApp so that it also supports WebSockets, additional to the HTTP methods listed above