alf 0.4.1

Python OAuth 2 Client

alf is a OAuth 2 Client based on requests.Session with seamless support for the Client Credentials Flow.

Features

• Automatic token retrieving and renewing

• Token expiration control

• Automatic retry on status 401 (UNAUTHORIZED)

Usage

Initialize the client and use it as a requests.Session object.

from alf.client import Client

alf = Client(
    token_endpoint='http://example.com/token',
    client_id='client-id',
    client_secret='secret')

resource_uri = 'http://example.com/resource'

alf.put(
    resource_uri, data='{"name": "alf"}',
    headers={'Content-Type': 'application/json'})

alf.get(resource_uri)

alf.delete(resource_uri)

How it works?

Before any request the client tries to retrive a token on the endpoint, expecting a JSON response with the access_token and expires_in keys.

The client keeps the token until it is expired, according to the expires_in value.

After getting the token, the request is issued with a Bearer authorization header:

GET /resource/1 HTTP/1.1
Host: example.com
Authorization: Bearer token

If the request fails with a 401 (UNAUTHORIZED) status, a new token is retrieved from the endpoint and the request is retried. This happens only once, if it fails again the error response is returned.

Troubleshooting

In case of an error retrieving a token, the error response will be returned, the real request won’t happen.

Related projects

djalf

Extended client that uses Django’s cache backend to share tokens between server instances.