I'm probably going to regret this name since it warrants an explanation and is slightly imprecise.
This is a gRPC interface for the Gy processing service (3GPP charging protocol) and Horde. There's nothing stopping you from using this from another process.
It's just a protobuf file and a sample server right now. If you don't know what "Horde", "Gy" or "gRPC" is you can safely ignore this repo.
You'll need the protobuf compiler to build this project.