Error with http3 AsyncClient

[updatatoday]

Describe the bug
Error using fastapi with http3 library https://github.com/encode/http3

To Reproduce

from fastapi import FastAPI
app = FastAPI()

@app.get('/')
async def root():
    return

import http3
client = http3.AsyncClient(app=app)
await client.get('http://test/')

Traceback:

Traceback (most recent call last):
  File "/Users/dzmitrysianiuk/.local/share/virtualenvs/backend-CYvvO53x/lib/python3.7/site-packages/IPython/core/interactiveshell.py", line 3292, in run_code
    last_expr = (yield from self._async_exec(code_obj, self.user_ns))
  File "<ipython-input-7-3f0100d218b8>", line 4, in async-def-wrapper
  File "/Users/dzmitrysianiuk/.local/share/virtualenvs/backend-CYvvO53x/lib/python3.7/site-packages/http3/client.py", line 302, in get
    timeout=timeout,
  File "/Users/dzmitrysianiuk/.local/share/virtualenvs/backend-CYvvO53x/lib/python3.7/site-packages/http3/client.py", line 534, in request
    timeout=timeout,
  File "/Users/dzmitrysianiuk/.local/share/virtualenvs/backend-CYvvO53x/lib/python3.7/site-packages/http3/client.py", line 136, in send
    await response.read()
  File "/Users/dzmitrysianiuk/.local/share/virtualenvs/backend-CYvvO53x/lib/python3.7/site-packages/http3/models.py", line 855, in read
    self._content = b"".join([part async for part in self.stream()])
  File "/Users/dzmitrysianiuk/.local/share/virtualenvs/backend-CYvvO53x/lib/python3.7/site-packages/http3/models.py", line 855, in <listcomp>
    self._content = b"".join([part async for part in self.stream()])
  File "/Users/dzmitrysianiuk/.local/share/virtualenvs/backend-CYvvO53x/lib/python3.7/site-packages/http3/models.py", line 866, in stream
    async for chunk in self.raw():
  File "/Users/dzmitrysianiuk/.local/share/virtualenvs/backend-CYvvO53x/lib/python3.7/site-packages/http3/models.py", line 885, in raw
    await self.close()
  File "/Users/dzmitrysianiuk/.local/share/virtualenvs/backend-CYvvO53x/lib/python3.7/site-packages/http3/models.py", line 895, in close
    await self.on_close()
  File "/Users/dzmitrysianiuk/.local/share/virtualenvs/backend-CYvvO53x/lib/python3.7/site-packages/http3/dispatch/asgi.py", line 131, in on_close
    raise app_exc
  File "/Users/dzmitrysianiuk/.local/share/virtualenvs/backend-CYvvO53x/lib/python3.7/site-packages/http3/dispatch/asgi.py", line 101, in run_app
    await app(scope, receive, send)
  File "/Users/dzmitrysianiuk/.local/share/virtualenvs/backend-CYvvO53x/lib/python3.7/site-packages/starlette/applications.py", line 133, in __call__
    await self.error_middleware(scope, receive, send)
  File "/Users/dzmitrysianiuk/.local/share/virtualenvs/backend-CYvvO53x/lib/python3.7/site-packages/starlette/middleware/errors.py", line 122, in __call__
    raise exc from None
  File "/Users/dzmitrysianiuk/.local/share/virtualenvs/backend-CYvvO53x/lib/python3.7/site-packages/starlette/middleware/errors.py", line 100, in __call__
    await self.app(scope, receive, _send)
  File "/Users/dzmitrysianiuk/.local/share/virtualenvs/backend-CYvvO53x/lib/python3.7/site-packages/starlette/exceptions.py", line 73, in __call__
    raise exc from None
  File "/Users/dzmitrysianiuk/.local/share/virtualenvs/backend-CYvvO53x/lib/python3.7/site-packages/starlette/exceptions.py", line 62, in __call__
    await self.app(scope, receive, sender)
  File "/Users/dzmitrysianiuk/.local/share/virtualenvs/backend-CYvvO53x/lib/python3.7/site-packages/starlette/routing.py", line 585, in __call__
    await route(scope, receive, send)
  File "/Users/dzmitrysianiuk/.local/share/virtualenvs/backend-CYvvO53x/lib/python3.7/site-packages/starlette/routing.py", line 207, in __call__
    await self.app(scope, receive, send)
  File "/Users/dzmitrysianiuk/.local/share/virtualenvs/backend-CYvvO53x/lib/python3.7/site-packages/starlette/routing.py", line 40, in app
    response = await func(request)
  File "/Users/dzmitrysianiuk/.local/share/virtualenvs/backend-CYvvO53x/lib/python3.7/site-packages/fastapi/routing.py", line 109, in app
    dependency_overrides_provider=dependency_overrides_provider,
  File "/Users/dzmitrysianiuk/.local/share/virtualenvs/backend-CYvvO53x/lib/python3.7/site-packages/fastapi/dependencies/utils.py", line 376, in solve_dependencies
    dependant.query_params, request.query_params
  File "/Users/dzmitrysianiuk/.local/share/virtualenvs/backend-CYvvO53x/lib/python3.7/site-packages/starlette/requests.py", line 63, in query_params
    self._query_params = QueryParams(self._scope["query_string"])
KeyError: 'query_string'

Environment:

• OS: [e.g. macOS]
• python 3.7.2
• FastAPI Version 0.30.0
• http3 version 0.6.0

[tiangolo]

Sorry, I'm not sure what you are trying to achieve.

But await can only be used inside of async functions, so I guess that might be the first thing to check.

I'll close this, but feel free to add more comments.

Also, if you still have problems, you can create a self-contained example that I can run and see your error.

[Jonatha-Varjao]

Just a quick question @tiangolo, any plans to document how to add http3 support into FastAPI ? using aioquic maybe ?
I'm loving it, migrating from django/node frameworks to FastAPI.
Hoping, in a soon future, to contribute to the project.

[dmontagu]

For what it's worth, the "http3" library referenced in the original post in this issue has been renamed to httpx.

@Jonatha-Varjao If you are referring to the HTTP/3 protocol (and given your reference to QUIC, I think you probably are), my understanding is that support for that would happen at a lower level in the stack -- probably inside the ASGI server. So, it's a matter of gunicorn/uvicorn/your ASGI server of choice adding support for HTTP/3.

I think uvicorn still hasn't added HTTP/2 support yet (though it is planned); I'm not aware of any ASGI servers offering HTTP/3 support yet (though I haven't loooked).

[Yamita]

Hi Tiangolo,

Just wanted to make you aware that a HTTP3 lib project now exists for Python: https://github.com/aiortc/aioquic

I'm not a lib dev but it sounds like they have designed it to be implementable by other lib authors into their own project. Maybe it can be integrated to FastAPI. Hope that helps in some way.

Also very sorry if I posted this in a wrong section or something. Just passing on tech news I think you might find interesting without creating a new HTTP3 thread.

With Love,
Yamita

[k-tatiana]

Just as for probable reason for such traceback for me was a wrong endpoint passed to get method, for example check for slashes more carefullly

[wbarnha]

Thanks for making this post, and sorry if I'm creating unnecessary noise. You can use QUIC with newer versions of FastAPI if you pip install hypercorn[h3] and set the following when running your application:

import asyncio
from hypercorn.config import Config
from hypercorn.asyncio import serve

config = Config()
config.bind = ["localhost:5000"]
config.quic_bind = ["localhost:5000"]
config.keyfile = "/path/to/keyfile.pem"
config.certfile = "/path/to/certfile.pem"
asyncio.run(serve(fastapi_app, config))