FastAPI SSO

FastAPI plugin to enable SSO to most common providers (such as Facebook login, Google login and login via Microsoft Office 365 account).

This allows you to implement the famous Login with Google/Facebook/Microsoft buttons functionality on your backend very easily.

Support this project

If you'd like to support this project, consider buying me a coffee ☕. I tend to process Pull Requests faster when properly caffeinated 😉.

Supported login providers

Official

• Google
• Microsoft
• Facebook
• Spotify
• Fitbit
• Github (credits to Brandl for hint using accept header)
• generic (see docs)

Contributed

• Kakao (by Jae-Baek Song - thdwoqor)

See Contributing for a guide on how to contribute your own login provider.

Installation

Install using pip

pip install fastapi-sso

Install using poetry

poetry add fastapi-sso

Example

For more examples, see examples directory.

example.py

"""This is an example usage of fastapi-sso.
"""

from fastapi import FastAPI
from starlette.requests import Request
from fastapi_sso.sso.google import GoogleSSO

app = FastAPI()

google_sso = GoogleSSO("my-client-id", "my-client-secret", "https://my.awesome-web.com/google/callback")

@app.get("/google/login")
async def google_login():
    """Generate login url and redirect"""
    return await google_sso.get_login_redirect()


@app.get("/google/callback")
async def google_callback(request: Request):
    """Process login response from Google and return user info"""
    user = await google_sso.verify_and_process(request)
    return {
        "id": user.id,
        "picture": user.picture,
        "display_name": user.display_name,
        "email": user.email,
        "provider": user.provider,
    }

Run using uvicorn example:app.

Specify redirect_uri on request time

In scenarios you cannot provide the redirect_uri upon the SSO class initialization, you may simply omit the parameter and provide it when calling get_login_redirect method.

...

google_sso = GoogleSSO("my-client-id", "my-client-secret")

@app.get("/google/login")
async def google_login(request: Request):
    """Generate login url and redirect"""
    return await google_sso.get_login_redirect(redirect_uri=request.url_for("google_callback"))

@app.get("/google/callback")
async def google_callback(request: Request):
    ...

Specify scope

Since 0.4.0 you may specify scope when initializing the SSO class.

from fastapi_sso.sso.microsoft import MicrosoftSSO

sso = MicrosoftSSO(client_id="client-id", client_secret="client-secret", scope=["openid", "email"])

Additional query parameters

Since 0.4.0 you may provide additional query parameters to be sent to the login screen.

E.g. sometimes you want to specify access_type=offline or prompt=consent in order for Google to return refresh_token.

async def google_login(request: Request):
    return await google_sso.get_login_redirect(
        redirect_uri=request.url_for("google_callback"),
        params={"prompt": "consent", "access_type": "offline"}
        )

HTTP and development

You should always use https in production. But in case you need to test on localhost and do not want to use self-signed certificate, make sure you set up redirect uri within your SSO provider to http://localhost:{port} and then add this to your environment:

OAUTHLIB_INSECURE_TRANSPORT=1

And make sure you pass allow_insecure_http = True to SSO class' constructor, such as:

google_sso = GoogleSSO("client-id", "client-secret", allow_insecure_http=True)

See this issue for more information.

State

State is useful if you want the server to return something back to you to help you understand in what context the authentication was initiated. It is mostly used to store the url you want your user to be redirected to after successful login. You may use .state property to get the state returned from the server.

Example:

from fastapi import Request
from fastapi.responses import RedirectResponse

# E.g. https://example.com/auth/login?return_url=https://example.com/welcome
async def google_login(return_url: str):
    google_sso = GoogleSOO("client-id", "client-secret")
    # Send return_url to Google as a state so that Google knows to return it back to us
    return await google_sso.get_login_redirect(redirect_uri=request.url_for("google_callback"), state=return_url)

async def google_callback(request: Request):
    google_sso = GoogleSOO("client-id", "client-secret")
    user = await google_sso.verify_and_process(request)
    # google_sso.state now holds your return_url (https://example.com/welcome)
    return RedirectResponse(google_sso.state)

Deprecation Warning: legacy use_state argument in SSOBase constructor is deprecated and will be removed.

Contributing

If you'd like to contribute and add your specific login provider, please see CONTRIBUTING.md file.