Source documentation

The FreeCAD source code is commented to allow automatic programming documentation generation using Doxygen, a popular source code documentation system. Doxygen can document both the C++ and Python parts of FreeCAD, resulting in offline HTML pages with links to each documented function and class.

The online source documentation is located at the FreeCAD API website. Please note that this documentation is not always up to date; if you need more details, consider downloading FreeCAD's latest source code and compiling the documentation yourself. If you have pressing questions about the code please ask in the developer section of the FreeCAD forum.

Compiling the API documentation follows the same general steps as compiling the FreeCAD executable, as indicated in the compile on Unix page.



Build source documentation
If you have Doxygen installed, it is very easy to build the documentation. Also install Graphviz to be able to produce diagrams showing the relationships between different classes and libraries in the FreeCAD code. Graphviz is also used by FreeCAD's dependency graph to show the relationships between different objects.

Then follow the same steps you would do to compile FreeCAD, as described on the compile on Unix page, and summarized here for convenience.
 * Get the source code of FreeCAD and place it in its own directory.
 * Create another directory in which you will compile FreeCAD and its documentation.
 * Configure the sources with, making sure you indicate the source directory, and specify the required options for your build.
 * Trigger the creation of the documentation using.

While you are inside the build directory issue the following instruction to create only the documentation.

As mentioned in compiling (speeding up), the option sets the number of CPU cores used for compilation. The resulting documentation files will appear in the directory

The point of entrance to the documentation is the file, which you can open with a web browser:

The target will generate a significant amount of data, around 5 GB of new files, particularly due to the diagrams created by Graphviz.

An alternative, smaller version of the documentation which takes only around 600 MB can be generated with a different target. This is the version displayed on the FreeCAD API website.

Other versions
FreeCAD 0.12 documentation hosted in Sourceforge.

FreeCAD 0.16 development documentation built by qingfeng.xia.

FreeCAD 0.19 development documentation built by qingfeng.xia.

Integrate Coin3D documentation
On Unix systems it is possible to link Coin3D source documentation with FreeCAD's. This allows for easier navigation and complete inheritance diagrams for Coin derived classes.


 * Install the, , or similarly named package.
 * Unpack the archive located in ; the files may be already unpacked in your system.
 * Generate again the source documentation.

If you don't install the documentation package for Coin, the links will be generated to access the online documentation at BitBucket. This will happen if a Doxygen tag file can be downloaded at configure time with.

How to integrate doxygen in to the FreeCAD source code
This section explains how to comment your source code so that it can be processed by Doxygen to automatically create the documentation.

This is an example of how source code is documented. It looks into the source code of VTK, a 3D visualization library used to present multi-physics simulation results.

A class to store a collection of coordinates is defined in a C++ header file. The top part of the file is commented, and a few keywords are used, like, , , and to indicate important parts. Inside the class, before a function is called, a block of commented text explains what the function does, and its arguments.


 * Source code of vtkArrayCoordinates.h defining the class
 * Doxygen produced documentation page for vtkArrayCoordinates class