#!/usr/bin/env node
/**
* Ultra-fast Minimal MCP Server for Testing
*
* This is an optimized version that uses direct buffer-based I/O
* instead of readline interface for faster startup and response times.
*/
const serverName = process.argv[2] || 'test-server';
// Pre-build response objects to avoid repeated JSON serialization
const initializeResponse = JSON.stringify({
jsonrpc: '2.0',
result: {
protocolVersion: '2024-11-05',
capabilities: { tools: {}, resources: {} },
serverInfo: { name: serverName, version: '1.0.0' },
},
});
const toolsListResponse = JSON.stringify({
jsonrpc: '2.0',
result: {
tools: [
{
name: 'test_tool',
description: `A test tool from ${serverName}`,
inputSchema: {
type: 'object',
properties: {
message: { type: 'string', description: 'A test message' },
},
},
},
{
name: `${serverName}_tool`,
description: `A tool for ${serverName}`,
inputSchema: {
type: 'object',
properties: {
message: { type: 'string', description: 'A test message' },
},
},
},
],
},
});
const resourcesListResponse = JSON.stringify({
jsonrpc: '2.0',
result: {
resources: [
{
uri: `test://${serverName}/resource1`,
name: `${serverName}_1mcp_test_resource`,
description: `A test resource from ${serverName}`,
mimeType: 'text/plain',
},
],
},
});
const promptsListResponse = JSON.stringify({
jsonrpc: '2.0',
result: {
prompts: [
{
name: `${serverName}_1mcp_test_prompt`,
description: `A test prompt from ${serverName}`,
arguments: [
{
name: 'message',
description: 'A test message',
required: false,
},
],
},
],
},
});
// Signal ready immediately
process.stderr.write(`${serverName} ready\n`);
// Buffer for incoming data
let buffer = Buffer.alloc(0);
// Process each line in buffer
function processBuffer() {
while (true) {
const newlineIndex = buffer.indexOf('\n');
if (newlineIndex === -1) break;
// Extract line
const lineBytes = buffer.subarray(0, newlineIndex);
buffer = buffer.subarray(newlineIndex + 1);
if (lineBytes.length === 0) continue;
try {
const request = JSON.parse(lineBytes.toString('utf8'));
// Build response based on method
let responseStr;
let id = request.id;
if (request.method === 'initialize') {
responseStr = initializeResponse.slice(0, -1) + `,"id":${id}}`;
} else if (request.method === 'tools/list') {
responseStr = toolsListResponse.slice(0, -1) + `,"id":${id}}`;
} else if (request.method === 'resources/list') {
responseStr = resourcesListResponse.slice(0, -1) + `,"id":${id}}`;
} else if (request.method === 'prompts/list') {
responseStr = promptsListResponse.slice(0, -1) + `,"id":${id}}`;
} else if (request.method === 'tools/call') {
responseStr = JSON.stringify({
jsonrpc: '2.0',
id,
result: {
content: [
{
type: 'text',
text: `Called ${request.params.name} on ${serverName}`,
},
],
},
});
} else if (request.method === 'ping') {
responseStr = JSON.stringify({
jsonrpc: '2.0',
id,
result: {},
});
} else {
// Unknown method
responseStr = JSON.stringify({
jsonrpc: '2.0',
id,
error: { code: -32601, message: `Method not found: ${request.method}` },
});
}
process.stdout.write(responseStr + '\n');
} catch {
// Parse error - send error response
process.stdout.write(
JSON.stringify({
jsonrpc: '2.0',
id: null,
error: { code: -32700, message: 'Parse error' },
}) + '\n',
);
}
}
}
// Handle incoming data
process.stdin.on('data', (data) => {
buffer = Buffer.concat([buffer, data]);
processBuffer();
});
// Keep process alive
process.on('SIGINT', () => {
process.exit(0);
});
