Contributing to Sphinx

There are many ways you can contribute to Sphinx, be it filing bug reports or feature requests, writing new documentation or submitting patches for new or fixed behavior. This guide serves to illustrate how you can get started with this.

Get help

The Sphinx community maintains a number of mailing lists and IRC channels.

Stack Overflow with tag python-sphinx

Questions and answers about use and development.

sphinx-users <>

Mailing list for user support.

sphinx-dev <>

Mailing list for development related discussions.

#sphinx-doc on

IRC channel for development questions and user support.

Bug Reports and Feature Requests

If you have encountered a problem with Sphinx or have an idea for a new feature, please submit it to the issue tracker on GitHub or discuss it on the sphinx-dev mailing list.

For bug reports, please include the output produced during the build process and also the log file Sphinx creates after it encounters an unhandled exception. The location of this file should be shown towards the end of the error message.

Including or providing a link to the source files involved may help us fix the issue. If possible, try to create a minimal project that produces the error and post that instead.

Contribute code

The Sphinx source code is managed using Git and is hosted on GitHub. The recommended way for new contributors to submit code to Sphinx is to fork this repository and submit a pull request after committing changes to their fork. The pull request will then need to be approved by one of the core developers before it is merged into the main repository.

Getting started

Before starting on a patch, we recommend checking for open issues or open a fresh issue to start a discussion around a feature idea or a bug. If you feel uncomfortable or uncertain about an issue or your changes, feel free to email the sphinx-dev mailing list.

These are the basic steps needed to start developing on Sphinx.

  1. Create an account on GitHub.

  2. Fork the main Sphinx repository (sphinx-doc/sphinx) using the GitHub interface.

  3. Clone the forked repository to your machine.

    git clone
    cd sphinx
  4. Checkout the appropriate branch.

    Sphinx adopts Semantic Versioning 2.0.0 (refs: ).

    For changes that preserves backwards-compatibility of API and features, they should be included in the next MINOR release, use the A.x branch.

    git checkout A.x

    For incompatible or other substantial changes that should wait until the next MAJOR release, use the master branch.

    For urgent release, a new PATCH branch must be branched from the newest release tag (see Sphinx’s release process for detail).

  5. Setup a virtual environment.

    This is not necessary for unit testing, thanks to tox, but it is necessary if you wish to run sphinx-build locally or run unit tests without the help of tox:

    virtualenv ~/.venv
    . ~/.venv/bin/activate
    pip install -e .
  6. Create a new working branch. Choose any name you like.

    git checkout -b feature-xyz
  7. Hack, hack, hack.

    Write your code along with tests that shows that the bug was fixed or that the feature works as expected.

  8. Add a bullet point to CHANGES.rst if the fix or feature is not trivial (small doc updates, typo fixes), then commit:

    git commit -m '#42: Add useful new feature that does this.'

    GitHub recognizes certain phrases that can be used to automatically update the issue tracker. For example:

    git commit -m 'Closes #42: Fix invalid markup in docstring of'

    would close issue #42.

  9. Push changes in the branch to your forked repository on GitHub:

    git push origin feature-xyz
  10. Submit a pull request from your branch to the respective branch (master or A.x).

  11. Wait for a core developer to review your changes.

Coding style

Please follow these guidelines when writing code for Sphinx:

  • Try to use the same code style as used in the rest of the project.

  • For non-trivial changes, please update the CHANGES.rst file. If your changes alter existing behavior, please document this.

  • New features should be documented. Include examples and use cases where appropriate. If possible, include a sample that is displayed in the generated output.

  • When adding a new configuration variable, be sure to document it and update sphinx/cmd/ if it’s important enough.

  • Add appropriate unit tests.

Style and type checks can be run as follows:

ruff check .
mypy sphinx/

Unit tests

Sphinx is tested using pytest for Python code and Karma for JavaScript.

To run Python unit tests, we recommend using tox, which provides a number of targets and allows testing against multiple different Python environments:

  • To list all possible targets:

    tox -av
  • To run unit tests for a specific Python version, such as Python 3.10:

    tox -e py310
  • To run unit tests for a specific Python version and turn on deprecation warnings so they’re shown in the test output:

    PYTHONWARNINGS=error tox -e py310
  • Arguments to pytest can be passed via tox, e.g., in order to run a particular test:

    tox -e py310 tests/

You can also test by installing dependencies in your local environment:

pip install .[test]

To run JavaScript tests, use npm:

npm install
npm run test


karma requires a Firefox binary to use as a test browser.

For Unix-based systems, you can specify the path to the Firefox binary using:

FIREFOX_BIN="/Applications/" npm test

New unit tests should be included in the tests directory where necessary:

  • For bug fixes, first add a test that fails without your changes and passes after they are applied.

  • Tests that need a sphinx-build run should be integrated in one of the existing test modules if possible. New tests that to @with_app and then build_all for a few assertions are not good since the test suite should not take more than a minute to run.

Added in version 1.8: Sphinx also runs JavaScript tests.

Added in version 1.6: sphinx.testing is added as a experimental.

Changed in version 1.5.2: Sphinx was switched from nose to pytest.

Utility functions and pytest fixtures for testing are provided in sphinx.testing. If you are a developer of Sphinx extensions, you can write unit tests by using pytest. At this time, sphinx.testing will help your test implementation.

How to use pytest fixtures that are provided by sphinx.testing? You can require 'sphinx.testing.fixtures' in your test modules or files like this:

pytest_plugins = 'sphinx.testing.fixtures'

If you want to know more detailed usage, please refer to tests/ and other test_*.py files under the tests directory.

Contribute documentation

Contributing to documentation involves modifying the source files found in the doc/ folder. To get started, you should first follow Getting started, and then take the steps below to work with the documentation.

The following sections describe how to get started with contributing documentation, as well as key aspects of a few different tools that we use.

Build the documentation

To build the documentation, run the following command:

sphinx-build -M html ./doc ./build/sphinx -W --keep-going

This will parse the Sphinx documentation’s source files and generate HTML for you to preview in build/sphinx/html.

You can also build a live version of the documentation that you can preview in the browser. It will detect changes and reload the page any time you make edits. To do so, run the following command:

sphinx-autobuild ./doc ./build/sphinx/


The parts of messages in Sphinx that go into builds are translated into several locales. The translations are kept as gettext .po files translated from the master template sphinx/locale/sphinx.pot.

Sphinx uses Babel to extract messages and maintain the catalog files. The utils directory contains a helper script,

  • Use python extract to update the .pot template.

  • Use python update to update all existing language catalogs in sphinx/locale/*/LC_MESSAGES with the current messages in the template file.

  • Use python compile to compile the .po files to binary .mo files and .js files.

When an updated .po file is submitted, run python compile to commit both the source and the compiled catalogs.

When a new locale is submitted, add a new directory with the ISO 639-1 language identifier and put sphinx.po in there. Don’t forget to update the possible values for language in doc/usage/configuration.rst.

The Sphinx core messages can also be translated on Transifex. There tx client tool, which is provided by the transifex_client Python package, can be used to pull translations in .po format from Transifex. To do this, go to sphinx/locale and then run tx pull -f -l LANG where LANG is an existing language identifier. It is good practice to run python update afterwards to make sure the .po file has the canonical Babel formatting.

Debugging tips

  • Delete the build cache before building documents if you make changes in the code by running the command make clean or using the sphinx-build -E option.

  • Use the sphinx-build -P option to run pdb on exceptions.

  • Use node.pformat() and node.asdom().toxml() to generate a printable representation of the document structure.

  • Set the configuration variable keep_warnings to True so warnings will be displayed in the generated output.

  • Set the configuration variable nitpicky to True so that Sphinx will complain about references without a known target.

  • Set the debugging options in the Docutils configuration file.

  • JavaScript stemming algorithms in sphinx/search/non-minified-js/*.js are generated using snowball by cloning the repository, executing make dist_libstemmer_js and then unpacking the tarball which is generated in dist directory.

    Minified files in sphinx/search/minified-js/*.js are generated from non-minified ones using uglifyjs (installed via npm), with -m option to enable mangling.

  • The searchindex.js files found in the tests/js/fixtures/* directories are generated by using the standard Sphinx HTML builder on the corresponding input projects found in tests/js/roots/*. The fixtures provide test data used by the Sphinx JavaScript unit tests, and can be regenerated by running the utils/ script.