import type { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
import type { IncomingMessage, ServerResponse } from 'node:http';
import process from 'node:process';
import { createMcpExpressApp } from '@modelcontextprotocol/sdk/server/express.js';
import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js';
import { StreamableHTTPServerTransport } from '@modelcontextprotocol/sdk/server/streamableHttp.js';
export async function startServer(
createServer: () => McpServer,
isHttp: boolean = false,
): Promise<void> {
if (isHttp) {
await startStreamableHttpServer(createServer);
}
else {
await startStdioServer(createServer);
}
}
export async function startStdioServer(
createServer: () => McpServer,
): Promise<void> {
const server = createServer();
await server.connect(new StdioServerTransport());
console.error('Met Museum MCP server running on stdio');
const shutdown = () => {
server.close()
.catch((error) => {
console.error('[MCP Shutdown Error]', error);
})
.finally(() => {
process.exit(0);
});
};
process.on('SIGINT', shutdown);
process.on('SIGTERM', shutdown);
}
export async function startStreamableHttpServer(
createServer: () => McpServer,
): Promise<void> {
const port = Number.parseInt(process.env.PORT ?? '3001', 10);
const host = process.env.HOST ?? '127.0.0.1';
const allowedHostsEnv = process.env.ALLOWED_HOSTS;
const defaultAllowedHosts = ['localhost', '127.0.0.1'];
const allowedHosts = allowedHostsEnv
? allowedHostsEnv
.split(',')
.map(value => value.trim())
.filter(Boolean)
: defaultAllowedHosts;
const expressApp = createMcpExpressApp({
host,
allowedHosts: allowedHosts.length ? allowedHosts : undefined,
});
expressApp.all('/mcp', async (
req: IncomingMessage & { body?: unknown },
res: ServerResponse,
) => {
const server = createServer();
const transport = new StreamableHTTPServerTransport({
sessionIdGenerator: undefined,
});
res.on('close', () => {
transport.close().catch(() => {});
server.close().catch(() => {});
});
try {
await server.connect(transport);
await transport.handleRequest(req, res, req.body);
}
catch (error) {
console.error('[MCP HTTP Error]', error);
if (!res.headersSent) {
const body = JSON.stringify({
jsonrpc: '2.0',
error: { code: -32603, message: 'Internal server error' },
id: null,
});
res.writeHead(500, { 'content-type': 'application/json' });
res.end(body);
}
}
});
const httpServer = expressApp.listen(port, host, () => {
console.error(`Met Museum MCP server running on http://${host}:${port}/mcp`);
});
const shutdown = () => {
console.error('\nShutting down...');
httpServer.close(() => process.exit(0));
};
process.on('SIGINT', shutdown);
process.on('SIGTERM', shutdown);
await new Promise<void>((resolve, reject) => {
httpServer.once('listening', resolve);
httpServer.once('error', reject);
});
}
