Galette API documentation can be generated using doxygen apigen (https://www.doxygen.nl/).
A file named Doxyfile is provided in the sources to automate the process. To generate the documentation, just run from galette doc (current) directory:
$ doxygen
HTML files will be generated into apidocs directory.
API documentation is generated every night along with the nighlty archive; you can see it at: https://apidoc.galette.eu