nice! Have you seen prpc? nodir.io/post/138899670556/prpc. It is basically the same thing. Chrome Operations have been successfully using it for 2 years.
In addition to server/client implementations in Go, it has
- discovery service
- GUI for making requests with descriptor-based autocompletion (example)
- CLI tool for making requests, with authentication and descriptor-based flag parsing
- prpc-agnostic service interface decorator generator
- server implementation for Python