import express from 'express';
import { randomUUID } from 'node:crypto';
import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
import { z } from 'zod';
import { statefulHandlers } from '../src/index.js';
// Create Express app
const app = express();
app.use(express.json());
function serverFactory() {
const server = new McpServer({
name: 'stateful-example-server',
version: '1.0.0',
});
server.tool(
'echo',
{ message: z.string() },
async ({ message }) => ({ content: [{ type: 'text', text: `Echo: ${message}` }] })
);
return server;
}
// Configure the stateful handler
const handlers = statefulHandlers(serverFactory, {
sessionIdGenerator: () => randomUUID(),
onSessionInitialized: (sessionId: string) => {
console.log(`Session initialized: ${sessionId}`);
},
onSessionClosed: (sessionId: string) => {
console.log(`Session closed: ${sessionId}`);
},
onInvalidSession: (req: express.Request) => {
console.log('Invalid or missing session ID', req.headers);
},
onError: (error: Error, sessionId: string | undefined) => {
console.error(`Error in session ${sessionId || 'unknown'}:`, error);
}
});
// Mount the handler on multiple HTTP methods
app.post('/mcp', handlers.postHandler);
app.get('/mcp', handlers.getHandler);
app.delete('/mcp', handlers.deleteHandler);
// Start the server
const PORT = process.env.PORT || 3000;
app.listen(PORT, () => {
console.log(`Stateful MCP server running on port ${PORT}`);
});
