import { Server as HttpServer, IncomingMessage, ServerResponse } from 'http';
/**
* Creates a simple HTTP transport for MCP Server (like old version)
* This implements JSON-RPC 2.0 over HTTP POST
*/
export function createHttpTransport(path: string, server: HttpServer) {
// Store the current response object for sending replies
let currentResponse: ServerResponse | null = null;
let responseTimeout: NodeJS.Timeout | null = null;
// Helper function to parse JSON body
async function parseBody(req: IncomingMessage): Promise<any> {
return new Promise((resolve, reject) => {
const chunks: Buffer[] = [];
const maxSize = 50 * 1024 * 1024; // 50MB limit
let totalSize = 0;
req.on('data', (chunk: Buffer) => {
totalSize += chunk.length;
if (totalSize > maxSize) {
reject(new Error('Request body too large'));
return;
}
chunks.push(chunk);
});
req.on('end', () => {
try {
const body = Buffer.concat(chunks).toString('utf8');
resolve(body ? JSON.parse(body) : {});
} catch (error) {
reject(new Error('Invalid JSON'));
}
});
req.on('error', reject);
});
}
// Helper function to send JSON response
function sendJson(res: ServerResponse, statusCode: number, data: any) {
res.statusCode = statusCode;
res.setHeader('Content-Type', 'application/json');
res.end(JSON.stringify(data));
}
// Create the transport object that MCP Server expects
const transport = {
// Callback functions
onmessage: undefined as ((message: any) => void) | undefined,
onclose: undefined as (() => void) | undefined,
onerror: undefined as ((error: Error) => void) | undefined,
// Start the transport and setup HTTP endpoint
async start() {
server.on('request', async (req: IncomingMessage, res: ServerResponse) => {
// Only handle POST requests to the specified path
if (req.method !== 'POST' || req.url !== path) {
res.statusCode = 404;
res.end();
return;
}
try {
// Parse request body
const body = await parseBody(req);
// Log incoming request for debugging
const method = body.method || 'unknown';
console.log(`[DEBUG] HTTP Transport: received ${method}`);
// Check if this is a notification
const hasId = body.hasOwnProperty('id') && body.id !== null && body.id !== undefined;
const isNotification = !hasId || (typeof method === 'string' && method.startsWith('notifications/'));
// For notifications, send immediate empty response
if (isNotification) {
// Process the notification asynchronously
if (this.onmessage) {
this.onmessage(body);
}
// Send immediate empty response for notifications
res.statusCode = 204;
res.end();
return;
}
// For regular requests, store the response object
currentResponse = res;
// Set a timeout to prevent hanging connections
const timeoutMs = 60000; // 60 seconds
responseTimeout = setTimeout(() => {
console.log(`[WARN] HTTP Transport: timeout for ${method}`);
if (currentResponse) {
sendJson(currentResponse, 500, {
jsonrpc: '2.0',
error: {
code: -32603,
message: 'Request timeout',
data: `Method ${method} did not respond within 60 seconds`
},
id: body.id || null
});
currentResponse = null;
}
}, timeoutMs);
// Pass the message to the MCP server
if (this.onmessage) {
this.onmessage(body);
}
} catch (error) {
console.error('[ERROR] HTTP Transport: Error handling request', error);
sendJson(res, 500, {
jsonrpc: '2.0',
error: {
code: -32603,
message: 'Internal error',
data: error instanceof Error ? error.message : String(error)
},
id: null
});
}
});
},
// Send a message (used to send responses)
async send(message: any): Promise<void> {
console.log(`[DEBUG] HTTP Transport: sending response`);
// Clear timeout if set
if (responseTimeout) {
clearTimeout(responseTimeout);
responseTimeout = null;
}
// Send the response if we have a response object
if (currentResponse) {
sendJson(currentResponse, 200, message);
currentResponse = null;
}
return Promise.resolve();
},
// Close the transport
async close(): Promise<void> {
console.log('[DEBUG] HTTP Transport: closing');
// Clear any pending timeout
if (responseTimeout) {
clearTimeout(responseTimeout);
responseTimeout = null;
}
// Clear response object
currentResponse = null;
if (this.onclose) {
this.onclose();
}
return Promise.resolve();
}
};
return transport;
}
