Documentation Status Latest Version Code Coverage Report License BSD-3 Clause

Automatic C++ library API documentation generator using Doxygen, Sphinx, and Breathe. Exhale revives Doxygen’s class, file, and page hierarchies in reStructuredText documents to make these hierarchies available in Sphinx documented projects.

Please read the Overview section if you are new to documenting code with either Doxygen, Sphinx, or Breathe. A Quickstart Guide gives the bare minimum needed to get things working.


This documentation was generated using exhale version 0.3.7.dev from commit 52a09209a02fccd34fd4cda6cac6431e372b2e95.

Is it For Me?

Exhale might not be the tool you are looking for! It was designed to be as intuitive and flexible as possible, but it does require more machinery to get everything started.

Why use it?

You would use Exhale if you want to have beautiful Sphinx generated websites, but also see the value of the Class, File, and Page hierarchies provided by Doxygen. From running Doxygen for you, to organizing your full API every time, you won’t need to worry about your documentation getting out of sync with the code — it’s regenerated on the fly every time.

Why not use it?

It may be more involved than you need. Check out the breathe-apidoc tool that comes with your installation of breathe. It is quite similar to the Sphinx API doc tool, and that may be all you are looking for to get your documentation displayed.

If you are working with a small enough framework, you may also be satisfied with just using the .. autodoxygenindex:: directive from breathe. It works very well!

The Main Difference

The Class, File, and Page hierarchies are only available in Sphinx via Exhale 😊

Depending on the size and complexity of your project, breathe-apidoc or autodoxygenindex may be more appropriate.

Important Consideration

Exhale is known to work well on small to medium sized projects. Supporting larger projects in Sphinx is a much more involved process that may or may not be resolved over time – this has to do with a lot more than just Exhale, but the nature of Exhale (generation of a large number of .rst files) definitely does not help.

Please see the full documentation for more information on how to get started.

See it in Action

The ExhaleCompanion repository has three builds to demonstrate the different options with respect to creating a Tree View, as well as details of specific HTML Theme choices:

HTML Theme Choice

TreeView Created

ExhaleCompanion Docs

RTD Theme



Bootstrap Theme







Exhale is a Sphinx Extension that depends on Breathe for access to the Doxygen reStructuredText directives, and both BeautifulSoup and lxml for parsing the generated Doxygen XML documentation. Exhale is hosted on PyPI, meaning you can install it through the normal mechanisms, e.g.,

$ python -m pip install exhale

This will install Exhale, as well as all of its dependencies.

Exhale Version Compatibility with Python, Sphinx, and Breathe

Exhale Version

Python Version

Sphinx Version

Breathe Version

0.3.2 – 0.3.6








0.2.1 – 0.2.4

2.7, 3.3+




2.7, 3.3+



For your project’s documentation requirements, adopting exhale@0.3.0 means you just need to specify directly that your docs/requirements.txt or similar express:


The exhale@0.3.0 release uses the same dependencies required by breathe@4.32.0. If you need python 3.5 support, pin your documentation requirements to:


For Python 2.7, you should pin your documentation requirements to:


Order matters, namely that sphinx and breathe appear / are installed before exhale. Exhale 0.2.* releases support Python 2.7, but users need to be aware of the dependencies between Python, Sphinx, and Breathe versions.


This project could not exist without the already excellent tools available: Doxygen, Sphinx, Breathe, and many others. In particular, though, for the Tree View hierarchies to be successful, I vendor copies of two excellent libraries that I make no claims to. They are vendored with your installation of Exhale, in accordance with each project’s license:

  1. For non-bootstrap, I used Kate Morley’s excellent and lightweight collapsibleLists including the sample CSS / images on that post. She includes a generous CC0 1.0 license for these files, as well as the rest of her website.

    For every HTML Theme I have tried, except for ones using bootstrap, this library works reliably and consistently. It matches the Sphinx RTD theme quite well, too!

  2. For bootstrap, I used Jon Miles’ comprehensive bootstrap-treeview library. Jon Miles hosts this library using the Apache v2 license.

    This library is exceptionally well thought out and enables an impressive amount of customization. At this time, Exhale does not expose any of the available customizations. If there is a specific one you’d like to see, please join the discussion here.

Both of these libraries and copies of their licenses can be found in the data folder of the source code.


This project uses a BSD 3-clause license, in hopes that it will be accessible to most projects. If you require a different license, please raise an issue and I will consider a dual license.

The full license is available here.

Full Documentation