Authdog

Python · Flask

Authentication for Flask

A session resolver, a require_auth decorator, and a logout handler for Flask. The context resolves once and caches on flask.g. Validate Authdog sessions on every request, on the same wire as the Node SDKs.

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PyPI versionCI passing
One call for the session
Call authdog.session() in any view for a typed AuthdogContext, cached on flask.g with no per-request wiring.
One enforcement point
Decorate a view with @authdog.require_auth and unauthenticated requests get a 401 before your view runs.
Resolved once per request
The context lives on flask.g, so repeated session() calls never trigger a second userinfo lookup.
Plain Flask
Ordinary view decorators that compose with blueprints and leave your app structure unchanged.

Wire up the app

# app.py
from flask import Flask
from authdog.flask import Authdog

app = Flask(__name__)
authdog = Authdog(public_key=os.environ["PK_AUTHDOG"])

@app.get("/")
def index():
    return {"authenticated": authdog.session().is_authenticated}

Gate views with a decorator

# app.py
@app.get("/me")
@authdog.require_auth
def me():
    return authdog.session().user

Decorators and flask.g

Everything Flask apps need

A drop-in session resolver, a require_auth decorator, and a typed context cached on flask.g.

01

A session on flask.g

authdog.session() resolves the request's session and caches it on flask.g, returning a typed AuthdogContext with token, user, and is_authenticated from any view.

  • Typed AuthdogContext
  • Cached on flask.g
02

require_auth decorator

Stack @authdog.require_auth on a view and Flask rejects unauthenticated requests with a 401, returning the user object otherwise. This is the security boundary.

  • 401 before your view
  • Returns the verified user
03

At most one userinfo call

The resolved context is cached on flask.g, so calling session() several times in one request still makes a single outbound userinfo call.

  • One outbound call
  • Repeat calls are free
04

Plain Flask decorators

The bindings are ordinary view decorators. Stack them under your route, combine them with blueprints, and keep your app's structure unchanged.

  • Works with blueprints
  • No app restructuring
05

Safe logout handler

authdog.logout() returns a redirect Response that expires the session cookie and redirects to a redirect_uri sanitized against open redirects.

  • Expires the cookie
  • Open-redirect safe
06

Same wire as Node

It mirrors @authdog/express and @authdog/fastify on the wire, so one Authdog environment serves your Node and Flask services interchangeably.

  • One environment
  • Node and Python together
01

Install

pip install 'authdog-fastapi[flask]'.

02

Create the client

Instantiate Authdog with your environment's public key.

03

Gate views

Stack require_auth under the routes you protect.

Add auth to your Flask app.

pip install 'authdog-fastapi[flask]', add the decorator, and gate your views with require_auth today. Free to start, with secure defaults built in.

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