OpenBSC USSD external application

Hi, I’ve been looking into getting ussd working with an external application. I found a branch from last year (fairwaves/sup-ussd) that looks like it has implemented most of ussd sessions and possibly communicates with an external application. Does anyone know if it was finished or what still needs to be done? I also found a python script called ussd_example.py which looks like it is supposed to act as a gateway and receive used connections from openbsc. Is this correct and did it work or am I misunderstanding its purpose? Thanks! - Rowan Phipps