# Developing extensions overview¶

## Make an extension depend on another extension¶

Sometimes your extension depends on the functionality of another Sphinx extension. Most Sphinx extensions are activated in a project’s conf.py file, but this is not available to you as an extension developer.

To ensure that another extension is activated as a part of your own extension, use the Sphinx.setup_extension() method. This will activate another extension at run-time, ensuring that you have access to its functionality.

For example, the following code activates the recommonmark extension:

def setup(app):
app.setup_extension("recommonmark")


Note

Since your extension will depend on another, make sure to include it as a part of your extension’s installation requirements.