aospina/rpc ? reverse-engineered prompt

Build me a simple RPC demo app or library, something basic that shows how a client can call a function on a server and get a result back.

I want it to be easy to run and easy to understand, with a small example that shows the full flow from request to response. If you need to, look up current docs online for the best way to do it. Keep the code clean and minimal, and make sure the project can be opened and used without a lot of setup.

If it helps, include a tiny sample service, a client that calls it, and clear instructions for how to test it locally. I’m mainly looking for a working starting point for a basic RPC setup, not a huge production system.