sphinx-hoverxref is a Sphinx extension to add tooltips on the cross references of the documentation with the content of the linked section.

You can install sphinx-hoverxref from PyPI:

pip install sphinx-hoverxref

Or, alternatively, install it from GitHub directly (requires git):

pip install git+https://github.com/readthedocs/sphinx-hoverxref

Add this extension in your conf.py file as:

extensions = [
 # ... other extensions here

 'hoverxref.extension',
]

Check out the full documentation at https://sphinx-hoverxref.readthedocs.io/