Need help with betamax?
Click the “chat” button below for chat support from the developer who created it, or find similar developers for support.

About the developer

489 Stars 55 Forks Other 523 Commits 24 Opened issues


A VCR imitation designed only for python-requests.

Services available


Need anything else?

Contributors list


Betamax is a VCR_ imitation for requests. This will make mocking out requests much easier. It is tested on

Travis CI

Put in a more humorous way: "Betamax records your HTTP interactions so the NSA does not have to."

Example Use

.. code-block:: python

from betamax import Betamax
from requests import Session
from unittest import TestCase

with Betamax.configure() as config: config.cassette_library_dir = 'tests/fixtures/cassettes'

class TestGitHubAPI(TestCase): def setUp(self): self.session = Session() self.headers.update(...)

# Set the cassette in a line other than the context declaration
def test_user(self):
    with Betamax(self.session) as vcr:
        resp = self.session.get('',
                                auth=('user', 'pass'))
        assert resp.json()['login'] is not None

# Set the cassette in line with the context declaration
def test_repo(self):
    with Betamax(self.session).use_cassette('repo'):
        resp = self.session.get(
        assert resp.json()['owner'] != {}

What does it even do?

If you are unfamiliar with VCR_, you might need a better explanation of what Betamax does.

Betamax intercepts every request you make and attempts to find a matching request that has already been intercepted and recorded. Two things can then happen:

  1. If there is a matching request, it will return the response that is associated with it.
  2. If there is not a matching request and it is allowed to record new responses, it will make the request, record the response and return the response.

Recorded requests and corresponding responses - also known as interactions - are stored in files called cassettes. (An example cassette can be seen in the

examples section of the documentation
.) The directory you store your cassettes in is called your library, or your
cassette library

VCR Cassette Compatibility

Betamax can use any VCR-recorded cassette as of this point in time. The only caveat is that python-requests returns a URL on each response. VCR does not store that in a cassette now but we will. Any VCR-recorded cassette used to playback a response will unfortunately not have a URL attribute on responses that are returned. This is a minor annoyance but not something that can be fixed.

.. _VCR: .. _Travis CI: .. _examples section of the documentation: .. _cassette library:

We use cookies. If you continue to browse the site, you agree to the use of cookies. For more information on our use of cookies please see our Privacy Policy.