import net from "net";
import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js";
import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
import cors from "cors";
import type { Request, Response } from "express";
import { createServer } from "./server.js";
// Helper to find an available port
async function findAvailablePort(startPort: number, maxAttempts = 10): Promise<number> {
for (let port = startPort; port < startPort + maxAttempts; port++) {
const available = await new Promise<boolean>((resolve) => {
const server = net.createServer();
server.once("error", () => resolve(false));
server.once("listening", () => {
server.close();
resolve(true);
});
server.listen(port);
});
if (available) return port;
}
throw new Error(`No available port found between ${startPort} and ${startPort + maxAttempts - 1}`);
}
export async function startStreamableHTTPServer(createServerFn: () => McpServer): Promise<void> {
const startPort = parseInt(process.env.PORT ?? "3000", 10);
const port = await findAvailablePort(startPort);
const app = createMcpExpressApp({ host: "0.0.0.0" });
app.use(cors());
app.all("/mcp", async (req: Request, res: Response) => {
const server = createServerFn();
const transport = new StreamableHTTPServerTransport({
sessionIdGenerator: undefined,
});
res.on("close", () => {
transport.close().catch(() => {});
server.close().catch(() => {});
});
try {
await server.connect(transport);
await transport.handleRequest(req, res, req.body);
} catch (error) {
console.error("MCP error:", error);
if (!res.headersSent) {
res.status(500).json({
jsonrpc: "2.0",
error: { code: -32603, message: "Internal server error" },
id: null,
});
}
}
});
const httpServer = app.listen(port, (err) => {
if (err) {
console.error("Failed to start server:", err);
process.exit(1);
}
console.log(`MCP server listening on http://localhost:${port}/mcp`);
});
const shutdown = () => {
console.log("\nShutting down...");
httpServer.close(() => process.exit(0));
};
process.on("SIGINT", shutdown);
process.on("SIGTERM", shutdown);
}
export async function startStdioServer(createServerFn: () => McpServer): Promise<void> {
await createServerFn().connect(new StdioServerTransport());
}
async function main() {
if (process.argv.includes("--stdio")) {
await startStdioServer(createServer);
} else {
await startStreamableHTTPServer(createServer);
}
}
main().catch((error) => {
console.error(error);
process.exit(1);
});
