FastAPI tutorial returns "Unknown client"

[koaning]

I'm trying out this tutorial but I seem to be stuck. When I click the authorize button from the FastAPI docs it leads me to:

So that seems like it's broken? But I'm unsure if it's broken on my end or on your server.

The tutorial might be better if it explained how to set the settings in the UI as well with some screenshots on where to get the settings. I think I've set it up correctly.

from fastapi import Depends, FastAPI
from fastapi.security import OAuth2AuthorizationCodeBearer
from fief_client import FiefAccessTokenInfo, FiefAsync
from fief_client.integrations.fastapi import FiefAuth

fief = FiefAsync(
    "base_url_from_tenant_menu",
    "45fu4...",
    "raMd...",
)

Did I misconfigure? Or was this a hiccup on your end?

[frankie567]

It looks like there is either something wrong with your base URL or your client ID. Several things to check:

• When you are redirected, the URL should look like this: https://mytenant.fief.dev/authorize?response_type=code&client_id=CLIENT_ID&redirect_uri=http%3A%2F%2Flocalhost:8000%auth%2Fcallback&scope=openid
• Clients are tied to one (and only one) tenant. So if you have several tenants, make sure the base URL corresponds to the client's tenant.

The tutorial might be better if it explained how to set the settings in the UI as well with some screenshots on where to get the settings. I think I've set it up correctly.

There are more details here: https://docs.fief.dev/integrate/python/#create-a-fief-client

[frankie567]

Ok, I think I figured out what we missed here! You probably forgot to change the base URL on the scheme below:

scheme = OAuth2AuthorizationCodeBearer(
    "https://example.fief.dev/authorize",  # Replace with your base URL here
    "https://example.fief.dev/api/token",  # And here
    scopes={"openid": "openid", "offline_access": "offline_access"},
)

Otherwise, the Swagger docs will redirect you to example.fief.dev, which obviously is not your tenant ;)

I improved the docs to heads up on this: https://docs.fief.dev/integrate/python/fastapi/#api-example

[koaning]

Good catch! I fixed the issue but hit my head against something else. I noticed that I was getting redirect errors. It seems that http://localhost:8000/docs/oauth2-redirect and http://127.0.0.1:8000/docs/oauth2-redirect are different URLs. After adding the 127.0.0.1 variant to the list as well I got a new issue though: when I log out and try to log back in I see this:

Just to check, is this an issue on my side?

[koaning]

In order to prevent any issues related to the Swagger page: is there a demo that I can download that just uses Jinja2 with FastApi and an actual login form? That would make it easier to confirm how easy it might be integrate with my project.

[frankie567]

You should probably try the web application example: https://docs.fief.dev/integrate/python/fastapi/#web-application-example

[chrisorner]

I had the exact same issues as @koaning. In the tutorial it is described that the redirect_uri http://localhost:8000/docs/oauth2-redirect has to be enabled but actually the uri with 127.0.0 needs to be enabled.

[shirkan]

Hi,
So I came across the same issue, and after I added http://127.0.0.1:8000/docs/oauth2-redirect to redirect URIs it seems to be working, but only with the main authorization button and after checking at least one scope.
@frankie567 I think this is worth mentioning in the tutorial in https://docs.fief.dev/integrate/python/fastapi/ as others might fall here, just like me and others have.
Thanks!

[frankie567]

This is explained in the Getting Started tutorial: https://docs.fief.dev/getting-started/try-oauth2/