deno-json-rpc

import {
  createRPC,
  RPC,
} from "https://deno.land/x/deno_json_rpc/src/rpc_two.ts";
// vscode_io is an implementation of VSCode-style I/O.
import {
  createVSCodeIO,
} from "https://deno.land/x/deno_json_rpc/src/vscode_io.ts";

// Create your RPC actor
const rpc: RPC = createRPC(createVSCodeIO(Deno.stdin, Deno.stdout));

// add a listener for methods you will receive (requests/notifications)
rpc.onRequest("CalculateOneAndOne", (_params: unknown) => {
  // Will automatically respond, assuming the return as the result
  return 1 + 1;
});

// Start the service
rpc.start();