The API is by no means stable yet.
It depends on glib, libsoup, libxml2, gnome-common and gtk-doc-tools:
apt-get install libsoup2.4-dev libglib2.0-dev libxml2-dev libgirepository1.0-dev \ gnome-common gtk-doc-tools
To build from source use:
./autogen.sh ./configure make
To install use
To run from the compiled source code use
./run python3 examples/trip-query.py Gelsenkirchen Essen
If you want to contribute to libplanfahr see the HACKING document.