/**
* SPDX-FileCopyrightText: © 2025 Talib Kareem <taazkareem@icloud.com>
* SPDX-License-Identifier: MIT
*
* SSE and HTTP Streamable Transport Server
*
* This module provides HTTP Streamable and legacy SSE transport support
* for the ClickUp MCP Server. It reuses the unified server configuration
* from server.ts to avoid code duplication.
*/
import { SSEServerTransport } from '@modelcontextprotocol/sdk/server/sse.js';
import { StreamableHTTPServerTransport } from '@modelcontextprotocol/sdk/server/streamableHttp.js';
import { isInitializeRequest } from '@modelcontextprotocol/sdk/types.js';
import express from 'express';
import { server } from './server.js';
import configuration from './config.js';
import { info, error as logError } from './logger.js';
const app = express();
app.use(express.json({ limit: '1mb' }));
export async function startSSEServer() {
const transports = {
streamable: {} as Record<string, StreamableHTTPServerTransport>,
sse: {} as Record<string, SSEServerTransport>,
};
// Streamable HTTP endpoint - handles POST requests for client-to-server communication
app.post('/mcp', async (req, res) => {
try {
const sessionId = req.headers['mcp-session-id'] as string | undefined;
let transport: StreamableHTTPServerTransport;
if (sessionId && transports.streamable[sessionId]) {
transport = transports.streamable[sessionId];
} else if (!sessionId && isInitializeRequest(req.body)) {
transport = new StreamableHTTPServerTransport({
sessionIdGenerator: () => `session_${Date.now()}_${Math.random().toString(36).substring(2, 15)}`,
onsessioninitialized: (sessionId) => {
transports.streamable[sessionId] = transport;
},
enableJsonResponse: true,
});
transport.onclose = () => {
if (transport.sessionId) {
delete transports.streamable[transport.sessionId];
}
};
await server.connect(transport);
} else {
res.status(400).json({
jsonrpc: '2.0',
error: {
code: -32000,
message: 'Bad Request: No valid session ID provided',
},
id: null,
});
return;
}
await transport.handleRequest(req, res, req.body);
} catch (error) {
logError('Error handling MCP request', error instanceof Error ? { message: error.message, stack: error.stack } : error);
if (!res.headersSent) {
res.status(500).json({
jsonrpc: '2.0',
error: {
code: -32603,
message: 'Internal server error',
},
id: null,
});
}
}
});
const handleSessionRequest = async (req: express.Request, res: express.Response) => {
const sessionId = req.headers['mcp-session-id'] as string | undefined;
if (!sessionId || !transports.streamable[sessionId]) {
res.status(400).send('Invalid or missing session ID');
return;
}
const transport = transports.streamable[sessionId];
await transport.handleRequest(req, res);
};
app.get('/mcp', handleSessionRequest);
app.delete('/mcp', handleSessionRequest);
// Legacy SSE endpoints (for backwards compatibility)
app.get('/sse', async (req, res) => {
const transport = new SSEServerTransport('/messages', res);
transports.sse[transport.sessionId] = transport;
info('New SSE connection established', { sessionId: transport.sessionId });
res.on('close', () => {
delete transports.sse[transport.sessionId];
});
await server.connect(transport);
});
app.post('/messages', async (req, res) => {
const sessionId = req.query.sessionId as string;
const transport = transports.sse[sessionId];
if (transport) {
await transport.handlePostMessage(req, res, req.body);
} else {
res.status(400).send('No transport found for sessionId');
}
});
const PORT = Number(configuration.port ?? '3231');
// Bind to all interfaces so Smithery can reach the Streamable HTTP endpoint
app.listen(PORT, '0.0.0.0', () => {
info('Streamable HTTP transport listening', {
port: PORT,
endpoints: {
streamable: '/mcp',
sse: '/sse'
}
});
}).on('error', (err) => {
logError('Failed to start HTTP transport server', { message: err.message, stack: err.stack });
process.exit(1);
});
}
