#!/usr/bin/env node
/**
* Manual JSON-RPC Test Script
*
* This script demonstrates how to manually send JSON-RPC messages to the MCP server.
* This is useful for understanding the MCP protocol at a low level.
*
* Usage:
* 1. Start your MCP server in one terminal: npm start
* 2. In another terminal, run this script: npm run test:manual
*
* Note: This script connects to an already-running server via stdio.
* However, since stdio is already taken by the terminal, this script
* spawns its own server instance for demonstration purposes.
*/
import { spawn } from 'child_process';
import { fileURLToPath } from 'url';
import { dirname, join } from 'path';
const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);
const serverPath = join(__dirname, '..', 'dist', 'index.js');
/**
* Send a JSON-RPC message to the server
*/
function sendMessage(server: any, message: any): Promise<any> {
return new Promise((resolve, reject) => {
const id = Date.now();
const request = {
jsonrpc: '2.0',
id,
...message,
};
let responseBuffer = '';
let errorBuffer = '';
// Set up response handler
const responseHandler = (data: Buffer) => {
responseBuffer += data.toString();
try {
const lines = responseBuffer.split('\n').filter((line) => line.trim());
for (const line of lines) {
const response = JSON.parse(line);
if (response.id === id) {
server.stdout.removeListener('data', responseHandler);
server.stderr.removeListener('data', errorHandler);
if (response.error) {
reject(new Error(response.error.message || 'Request failed'));
} else {
resolve(response.result);
}
return;
}
}
} catch (e) {
// Not a complete JSON response yet, wait for more
}
};
const errorHandler = (data: Buffer) => {
errorBuffer += data.toString();
// Log server output (MCP servers log to stderr)
if (data.toString().includes('started and ready')) {
console.log('ā
Server started');
}
};
server.stdout.on('data', responseHandler);
server.stderr.on('data', errorHandler);
// Send the request
server.stdin.write(JSON.stringify(request) + '\n');
// Timeout after 5 seconds
setTimeout(() => {
server.stdout.removeListener('data', responseHandler);
server.stderr.removeListener('data', errorHandler);
reject(new Error('Request timeout'));
}, 5000);
});
}
/**
* Manual test demonstration
*/
async function manualTest() {
console.log('š§ Manual JSON-RPC Test');
console.log('=======================\n');
console.log('This demonstrates the MCP protocol at a low level.\n');
// Spawn the server
const server = spawn('node', [serverPath], {
stdio: ['pipe', 'pipe', 'pipe'],
});
server.on('error', (error) => {
console.error('ā Failed to start server:', error.message);
console.error('\nMake sure you have run: npm run build');
process.exit(1);
});
// Wait for server to be ready
await new Promise((resolve) => {
server.stderr.on('data', (data) => {
if (data.toString().includes('started and ready')) {
console.log('ā
Server started\n');
resolve(undefined);
}
});
});
try {
// Step 1: Initialize the connection
console.log('š” Step 1: Sending initialize request...');
const initResponse = await sendMessage(server, {
method: 'initialize',
params: {
protocolVersion: '2024-11-05',
capabilities: {},
clientInfo: {
name: 'manual-test-client',
version: '1.0.0',
},
},
});
console.log('Initialize response:', JSON.stringify(initResponse, null, 2));
console.log('');
// Step 2: Send initialized notification
console.log('š” Step 2: Sending initialized notification...');
server.stdin.write(
JSON.stringify({
jsonrpc: '2.0',
method: 'notifications/initialized',
}) + '\n'
);
console.log('ā
Initialized notification sent\n');
// Wait a bit for the server to process
await new Promise((resolve) => setTimeout(resolve, 100));
// Step 3: List tools
console.log('š” Step 3: Requesting list of tools...');
const toolsResponse = await sendMessage(server, {
method: 'tools/list',
params: {},
});
console.log('Tools:', JSON.stringify(toolsResponse, null, 2));
console.log('');
// Step 4: Call a tool
console.log('š” Step 4: Calling calculator tool (6 Ć 7)...');
const calcResponse = await sendMessage(server, {
method: 'tools/call',
params: {
name: 'calculator',
arguments: {
operation: 'multiply',
a: 6,
b: 7,
},
},
});
console.log('Calculator result:', JSON.stringify(calcResponse, null, 2));
console.log('');
// Step 5: List resources
console.log('š” Step 5: Requesting list of resources...');
const resourcesResponse = await sendMessage(server, {
method: 'resources/list',
params: {},
});
console.log('Resources:', JSON.stringify(resourcesResponse, null, 2));
console.log('');
console.log('ā
Manual test completed successfully!');
console.log('\nš” This demonstrates the raw JSON-RPC protocol used by MCP.');
} catch (error) {
console.error('ā Test failed:', error);
if (error instanceof Error) {
console.error('Error:', error.message);
}
} finally {
server.kill();
}
}
// Run the test
manualTest().catch((error) => {
console.error('Fatal error:', error);
process.exit(1);
});
