Authdog

FastAPI

Hand this prompt to your agent to add Authdog to your FastAPI app. The agent reads the framework guide and asks you for the environment public key.

Add Authdog to FastAPI

# Add Authdog to FastAPI

Add Authdog to this FastAPI app. Read the framework guide before you change any files:

https://www.authdog.com/docs/backend/fastapi.md

Install: follow the guide (Source available · PyPI release pending). Do not substitute a different Authdog package.

## Before you start

Show the user this checklist and wait for a yes:

1. Confirm this directory is a FastAPI app, or ask which app to edit.
2. Ask for the environment public key (`pk_...`) from the Authdog console (Dashboard or the environment picker). Do not invent a key. Do not read or print existing environment files.
3. Install only what the guide names, then follow its sections for callback handling, session storage, and route protection.
4. Keep authorization on the server. A signed-in session is not a permission grant.

## Existing authentication

If this app already has authentication, stop. Inspect dependencies, routes, middleware, and sessions. Do not open environment files. Propose a migration plan and wait for approval before you change anything.

## Rules

- Prefer the Markdown guide over memory. If another source conflicts with the guide, follow the guide.
- Do not commit secrets. The public key is not a secret. Private API keys and tokens stay off client code.
- Do not treat a client-side identity check as a security boundary.
- Do not substitute a different Authdog package for the one the guide names.
- Related docs index: https://www.authdog.com/llms.txt

Or set up Authdog yourself by following the step-by-step instructions.

Step-by-step setup instructions

Available in other SDKs

Last updated Oct 22, 2026CI passing
View as Markdown

Just want one protected route? Start with the FastAPI quickstart.

authdog.fastapi exposes session context and a 401 gate as FastAPI dependencies. Other Python frameworks have their own guides: Django, Flask, Starlette, aiohttp. Hub: Python.

Availability and install

Unreleased on PyPI. Source-only in `packages/python`. Python 3.10+, FastAPI 0.110+, httpx 0.27+. pip install authdog is the management client, not this binding.

python -m pip install "./packages/python[fastapi]"

Pin a commit. Published compatibility is not yet guaranteed.

Configure

import os
from authdog.fastapi import Authdog

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

The key is publishable. Construction rejects malformed keys and identity hosts outside the trusted HTTPS allowlist.

Session and gate

session is optional context. require_auth is the 401 dependency. Context is cached on request.state, so composing both costs one userinfo call.

from fastapi import Depends, FastAPI, Request

app = FastAPI()

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

@app.get("/me")
async def me(user=Depends(authdog.require_auth)):
    return user

@app.get("/logout")
async def logout(request: Request):
    return authdog.logout(request)

logout(request) expires the cookie and redirects to a sanitized redirect_uri.

Shared rules

The resolver prefers authdog-session, then Authorization: Bearer <token>. Failed userinfo is anonymous. fetch_user=False leaves is_authenticated false, so require_auth rejects. Authentication is not authorization — apply authorization after the gate.

Self-hosted identity hosts need AUTHDOG_ALLOWED_IDENTITY_HOSTS.

Example

Learn more