Outcome: a Flask view that returns 401 unless Authdog authenticates the caller. About five minutes.

**Unreleased:** not on PyPI. Install from the public source tree.

0. Prerequisites: Python 3.10+, Flask 3.0+, and an Authdog environment.

## 1. Create an environment and copy the public key

In the [console](https://console.authdog.com), create a tenant → project → environment and copy **Public key** from **Dashboard**. Details: [Environments](/docs/console/environments).

## 2. Install from source

```bash
python -m pip install "./packages/python[flask]"
```

Pin [`packages/python`](https://github.com/authdog/web-sdk/tree/main/packages/python).

## 3. Set the env var

```bash
export PK_AUTHDOG="pk_..."
```

## 4. Construct the client

```python
import os
from flask import Flask
from authdog.flask import Authdog

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

## 5. Protect one view

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

## 6. Verify

`GET /me` without a session → 401. With a valid cookie or bearer token from hosted sign-in → user JSON.

If it fails: decorator order (route above `require_auth`); wrong environment key; used `session()` alone as a gate.

## Next

The [Flask guide](/docs/backend/flask) covers `flask.g` caching and logout. Other Python frameworks: [FastAPI](/docs/quickstarts?sdk=fastapi), [Django](/docs/quickstarts?sdk=django), [Starlette](/docs/quickstarts?sdk=starlette), [aiohttp](/docs/quickstarts?sdk=aiohttp).