#!/usr/bin/env node
/**
* Minimal MCP Server for Testing
*
* This script acts as a mock MCP server that responds to initialize and listTools requests.
* It's designed to be used in E2E tests where a real MCP server is needed.
*/
const readline = require('readline');
const rl = readline.createInterface({
input: process.stdin,
output: process.stdout,
terminal: false,
});
// Server configuration
const serverName = process.argv[2] || 'test-server';
const serverTools = [
{
name: 'test_tool',
description: `A test tool from ${serverName}`,
inputSchema: {
type: 'object',
properties: {
message: {
type: 'string',
description: 'A test message',
},
},
},
},
];
// Send ready notification immediately
console.error(`${serverName} ready`);
// Handle incoming requests
rl.on('line', (line) => {
try {
const request = JSON.parse(line);
// Handle initialize
if (request.method === 'initialize') {
const response = {
jsonrpc: '2.0',
id: request.id,
result: {
protocolVersion: '2024-11-05',
capabilities: {
tools: {},
},
serverInfo: {
name: serverName,
version: '1.0.0',
},
},
};
console.log(JSON.stringify(response));
return;
}
// Handle tools/list
if (request.method === 'tools/list') {
const response = {
jsonrpc: '2.0',
id: request.id,
result: {
tools: serverTools,
},
};
console.log(JSON.stringify(response));
return;
}
// Handle tools/call
if (request.method === 'tools/call') {
const response = {
jsonrpc: '2.0',
id: request.id,
result: {
content: [
{
type: 'text',
text: `Called ${request.params.name} on ${serverName} with args: ${JSON.stringify(request.params.arguments)}`,
},
],
},
};
console.log(JSON.stringify(response));
return;
}
// Unknown method
const errorResponse = {
jsonrpc: '2.0',
id: request.id,
error: {
code: -32601,
message: `Method not found: ${request.method}`,
},
};
console.log(JSON.stringify(errorResponse));
} catch (error) {
const errorResponse = {
jsonrpc: '2.0',
id: null,
error: {
code: -32700,
message: `Parse error: ${error.message}`,
},
};
console.log(JSON.stringify(errorResponse));
}
});
// Keep process alive
process.on('SIGINT', () => {
process.exit(0);
});
