json-rpc-2.0

import express from 'express'; import bodyParser from 'body-parser'; import { JSONRPCServer, JSONRPCClient } from 'json-rpc-2.0'; import fetch from 'node-fetch'; // For client in Node.js // --- Server Setup --- const server = new JSONRPCServer(); server.addMethod('echo', ({ text }) => text); server.addMethod('add', ({ a, b }) => a + b); server.addMethod('log', ({ message }) => console.log(message)); // Add a middleware for logging server.applyMiddleware(async (next, request, serverParams) => { console.log(`[Server Middleware] Received request: ${JSON.stringify(request)}`); const response = await next(request, serverParams); console.log(`[Server Middleware] Responding: ${JSON.stringify(response)}`); return response; }); const app = express(); app.use(bodyParser.json()); app.post('/json-rpc', (req, res) => { const jsonRPCRequest = req.body; server.receive(jsonRPCRequest).then((jsonRPCResponse) => { if (jsonRPCResponse) { res.json(jsonRPCResponse); } else { res.sendStatus(204); // Notification, no response needed } }); }); const PORT = 3000; app.listen(PORT, () => console.log(`JSON-RPC server listening on http://localhost:${PORT}/json-rpc`)); // --- Client Setup --- const client = new JSONRPCClient(async (jsonRPCRequest) => { const response = await fetch('http://localhost:3000/json-rpc', { method: 'POST', headers: { 'Content-Type': 'application/json', }, body: JSON.stringify(jsonRPCRequest), }); if (response.status === 204) { return; // Notification, no response } const jsonRPCResponse = await response.json(); client.receive(jsonRPCResponse); }); // --- Client Usage --- async function runClient() { try { console.log('\n--- Client Calls ---'); const echoResult = await client.request('echo', { text: 'Hello JSON-RPC' }); console.log('Echo result:', echoResult); const addResult = await client.request('add', { a: 5, b: 3 }); console.log('Add result:', addResult); // Send a notification (no response expected) client.notify('log', { message: 'Client sent a log message.' }); console.log('\n--- Client finished ---'); } catch (error) { console.error('Client error:', error); } } // Give server a moment to start setTimeout(runClient, 1000);