simpleStatelessStreamableHttp.ts•4.31 kB
import express, { Request, Response } from 'express';
import { McpServer } from '../../server/mcp.js';
import { StreamableHTTPServerTransport } from '../../server/streamableHttp.js';
import { z } from 'zod';
import { CallToolResult, GetPromptResult, ReadResourceResult } from '../../types.js';
const getServer = () => {
// Create an MCP server with implementation details
const server = new McpServer({
name: 'stateless-streamable-http-server',
version: '1.0.0',
}, { capabilities: { logging: {} } });
// Register a simple prompt
server.prompt(
'greeting-template',
'A simple greeting prompt template',
{
name: z.string().describe('Name to include in greeting'),
},
async ({ name }): Promise<GetPromptResult> => {
return {
messages: [
{
role: 'user',
content: {
type: 'text',
text: `Please greet ${name} in a friendly manner.`,
},
},
],
};
}
);
// Register a tool specifically for testing resumability
server.tool(
'start-notification-stream',
'Starts sending periodic notifications for testing resumability',
{
interval: z.number().describe('Interval in milliseconds between notifications').default(100),
count: z.number().describe('Number of notifications to send (0 for 100)').default(10),
},
async ({ interval, count }, { sendNotification }): Promise<CallToolResult> => {
const sleep = (ms: number) => new Promise(resolve => setTimeout(resolve, ms));
let counter = 0;
while (count === 0 || counter < count) {
counter++;
try {
await sendNotification({
method: "notifications/message",
params: {
level: "info",
data: `Periodic notification #${counter} at ${new Date().toISOString()}`
}
});
}
catch (error) {
console.error("Error sending notification:", error);
}
// Wait for the specified interval
await sleep(interval);
}
return {
content: [
{
type: 'text',
text: `Started sending periodic notifications every ${interval}ms`,
}
],
};
}
);
// Create a simple resource at a fixed URI
server.resource(
'greeting-resource',
'https://example.com/greetings/default',
{ mimeType: 'text/plain' },
async (): Promise<ReadResourceResult> => {
return {
contents: [
{
uri: 'https://example.com/greetings/default',
text: 'Hello, world!',
},
],
};
}
);
return server;
}
const app = express();
app.use(express.json());
app.post('/mcp', async (req: Request, res: Response) => {
const server = getServer();
try {
const transport: StreamableHTTPServerTransport = new StreamableHTTPServerTransport({
sessionIdGenerator: undefined,
});
await server.connect(transport);
await transport.handleRequest(req, res, req.body);
res.on('close', () => {
console.log('Request closed');
transport.close();
server.close();
});
} catch (error) {
console.error('Error handling MCP request:', error);
if (!res.headersSent) {
res.status(500).json({
jsonrpc: '2.0',
error: {
code: -32603,
message: 'Internal server error',
},
id: null,
});
}
}
});
app.get('/mcp', async (req: Request, res: Response) => {
console.log('Received GET MCP request');
res.writeHead(405).end(JSON.stringify({
jsonrpc: "2.0",
error: {
code: -32000,
message: "Method not allowed."
},
id: null
}));
});
app.delete('/mcp', async (req: Request, res: Response) => {
console.log('Received DELETE MCP request');
res.writeHead(405).end(JSON.stringify({
jsonrpc: "2.0",
error: {
code: -32000,
message: "Method not allowed."
},
id: null
}));
});
// Start the server
const PORT = 3000;
app.listen(PORT, () => {
console.log(`MCP Stateless Streamable HTTP Server listening on port ${PORT}`);
});
// Handle server shutdown
process.on('SIGINT', async () => {
console.log('Shutting down server...');
process.exit(0);
});