#!/usr/bin/env node
import express from 'express';
import cors from 'cors';
import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
import { SseServerTransport } from '@modelcontextprotocol/sdk/server/sse.js';
const app = express();
const PORT = process.env.PORT || 3003;
// Configure CORS
app.use(cors({
origin: '*',
methods: ['GET', 'POST', 'OPTIONS'],
allowedHeaders: ['Content-Type', 'Origin']
}));
// Create MCP server
const server = new McpServer(
{
name: "mcp-prompts-sse",
version: "1.0.0"
},
{
capabilities: {
resources: { subscribe: false },
tools: { listChanged: false },
prompts: { listChanged: false }
}
}
);
// Define some tools
server.tool(
'echo',
{
message: { type: 'string' }
},
async (params) => {
return {
type: 'object',
object: { echo: params.message }
};
}
);
// Configure SSE endpoint
app.get('/events', (req, res) => {
console.log('SSE connection request received');
// Set SSE headers
res.writeHead(200, {
'Content-Type': 'text/event-stream',
'Cache-Control': 'no-cache',
'Connection': 'keep-alive'
});
// Send a welcome message
res.write(`data: ${JSON.stringify({ type: 'connect', message: 'Connected to MCP Prompts SSE stream' })}\n\n`);
// Create the SSE transport
const transport = new SseServerTransport(req, res);
// Connect server to transport
server.connect(transport).catch(error => {
console.error('Error connecting server to transport:', error);
});
// Keep the connection alive with heartbeat
const heartbeat = setInterval(() => {
res.write(`data: ${JSON.stringify({ type: 'heartbeat', timestamp: new Date().toISOString() })}\n\n`);
}, 30000);
// Handle client disconnect
req.on('close', () => {
clearInterval(heartbeat);
console.log('SSE connection closed');
});
});
// Health check endpoint
app.get('/health', (req, res) => {
res.json({
status: 'healthy',
version: '1.0.0',
timestamp: new Date().toISOString(),
features: {
sse: true,
ssePath: '/events'
}
});
});
// Root endpoint
app.get('/', (req, res) => {
res.json({
name: 'mcp-prompts-sse',
version: '1.0.0',
endpoints: [
'/health',
'/events'
]
});
});
// Start the server
app.listen(PORT, () => {
console.log(`SSE server running on port ${PORT}`);
console.log(`SSE endpoint available at http://localhost:${PORT}/events`);
});
process.on('unhandledRejection', (error) => {
console.error('Unhandled rejection:', error);
});
