This is actually really cool! Any chance you can point me to an implementation for JSON-RPC? I'm interested to see the benefits with JSON-RPC over a traditional REST API.
The spec explains pretty much everything you need to know. Look for a client and server implementation in your language of choice; essentially all it needs to do is decode the JSON message and validate that it uses the right structure, and handle message IDs for batching, then call your custom message handling logic.
Over HTTP, basically you just have a single endpoint which always takes POST requests, and always responds with 200 status, even on errors. If you're using this in a frontend JS application, you'd want a wrapper over fetch() which rejects the promise if the RPC response has an error in the message.
