# Extensions

Sphinx/docs/4.1.x/usage/extensions/index

# Extensions

Since many projects will need special features in their documentation, Sphinx allows adding “extensions” to the build process, each of which can modify almost any aspect of document processing.

This chapter describes the extensions bundled with Sphinx. For the API documentation on writing your own extension, refer to Developing extensions for Sphinx.

## Third-party extensions

You can find several extensions contributed by users in the sphinx-contrib organization. If you wish to include your extension in this organization, simply follow the instructions provided in the github-administration project. This is optional and there are several extensions hosted elsewhere. The awesome-sphinxdoc project contains a curated list of Sphinx packages, and many packages use the Framework :: Sphinx :: Extension and Framework :: Sphinx :: Theme trove classifiers for Sphinx extensions and themes, respectively.

### Where to put your own extensions?

Extensions local to a project should be put within the project’s directory structure. Set Python’s module search path, sys.path, accordingly so that Sphinx can find them. For example, if your extension foo.py lies in the exts subdirectory of the project root, put into conf.py:

import sys, os

sys.path.append(os.path.abspath('exts'))

extensions = ['foo']

You can also install extensions anywhere else on sys.path, e.g. in the site-packages directory.