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.

Documentation: https://tomasvotava.github.io/fastapi-sso/

Source Code: https://github.com/tomasvotava/fastapi-sso

Demo site

An awesome demo site was created and is maintained by even awesomer Chris Karvouniaris (@chrisK824). Chris has also posted multiple Medium articles about FastAPI and FastAPI SSO.

Be sure to see his tutorials, follow him and show him some appreciation!

Please see his announcement with all the links.

Quick links for the eager ones:

• Demo site
• Medium articles

Security Notice

Version 0.16.0 Update: Race Condition Bug Fix & Context Manager Change

A race condition bug in the login flow that could, in rare cases, allow one user to assume the identity of another due to concurrent login requests was recently discovered by @parikls. This issue was reported in #186 and has been resolved in version 0.16.0.

Details of the Fix:

The bug was mitigated by introducing an async lock mechanism that ensures only one user can attempt the login process at any given time. This prevents race conditions that could lead to unintended user identity crossover.

Important Change:

To fully support this fix, users must now use the SSO instance within an async with context manager. This adjustment is necessary for proper handling of asynchronous operations.

The synchronous with context manager is now deprecated and will produce a warning. It will be removed in future versions to ensure best practices for async handling.

Impact:

This bug could potentially affect deployments with high concurrency or scenarios where multiple users initiate login requests simultaneously. To prevent potential issues and deprecation warnings, update to version 0.16.0 or later and modify your code to use the async with context.

Code Example Update:

# Before (deprecated)
with sso:
    openid = await sso.verify_and_process(request)

# After (recommended)
async with sso:
    openid = await sso.verify_and_process(request)

Thanks to both @parikls and the community for helping me identify and improve the security of fastapi-sso. If you encounter any issues or potential vulnerabilities, please report them immediately so they can be addressed.

For more details, refer to Issue #186 and PR #189.

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)
• Notion
• Twitter (X)

Contributed

• Kakao (by Jae-Baek Song - thdwoqor)
• Naver (by 1tang2bang92) - 1tang2bang92
• Gitlab (by Alessandro Pischedda) - Cereal84
• Line (by Jimmy Yeh) - jimmyyyeh
• LinkedIn (by Alessandro Pischedda) - Cereal84
• Yandex (by Akim Faskhutdinov) – akimrx
• Seznam (by Tomas Koutek) - TomasKoutek
• Discord (by Kaelian Baudelet) - afi-dev
• Bitbucket (by Kaelian Baudelet) - afi-dev

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

Contributing

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