Before contributing to Read the Docs, make sure your patch passes our test suite and your code style passes our code linting suite.

Read the Docs uses Tox to execute testing and linting procedures. Tox is the only dependency you need to run linting or our test suite, the remainder of our requirements will be installed by Tox into environment specific virtualenv paths. Before testing, make sure you have Tox installed:

pip install tox

To run the full test and lint suite against your changes, simply run Tox. Tox should return without any errors. You can run Tox against all of our environments by running:


By default, tox won’t run tests from search, in order to run all test including the search tests, you need to override tox’s posargs. If you don’t have any additional arguments to pass, you can also set the TOX_POSARGS environment variable to an empty string:



If you need to override tox’s posargs, but you still don’t want to run the search tests, you need to include -m 'not search' to your command:

tox -- -m 'not search' -x

To target a specific environment:

tox -e py310

To run a subset of tests:

tox -e py310 -- -k test_celery

The tox configuration has the following environments configured. You can target a single environment to limit the test suite:


Run our test suite using Python 3.10


Same as py310, but there are some useful debugging tools available in the environment.


Run code linting using Prospector. This currently runs pylint, pyflakes, pep8 and other linting tools.


Test documentation compilation with Sphinx.

Pytest marks

The Read the Docs code base is deployed as three instances:

  • Main: where you can see the dashboard.

  • Build: where the builds happen.

  • Serve/proxito: It is in charge of serving the documentation pages.

Each instance has its own settings. To make sure we test each part as close as possible to its real settings, we use pytest marks. This allow us to run each set of tests with different settings files, or skip some (like search tests):

DJANGO_SETTINGS_MODULE=custom.settings.file pytest -m mark
DJANGO_SETTINGS_MODULE=another.settings.file pytest -m "not mark"

Current marks are:

  • search (tests that require Elastic Search)

  • proxito (tests from the serve/proxito instance)

Tests without mark are from the main instance.

Continuous Integration

The RTD test suite is exercised by Circle CI on every push to our repo at GitHub. You can check out the current build status: https://app.circleci.com/pipelines/github/readthedocs/readthedocs.org