/**
* Entry point for running the MCP server.
* Run with: npx @mcp-demos/excalidraw-server
* Or: node dist/index.js [--stdio]
*/
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";
/**
* Starts an MCP server with Streamable HTTP transport in stateless mode.
*
* @param createServer - Factory function that creates a new McpServer instance per request.
*/
export async function startStreamableHTTPServer(
createServer: () => McpServer,
): Promise<void> {
const port = parseInt(process.env.PORT ?? "3001", 10);
const app = createMcpExpressApp({ host: "0.0.0.0" });
app.use(cors());
app.all("/mcp", async (req: Request, res: Response) => {
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 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);
}
/**
* Starts an MCP server with stdio transport.
*
* @param createServer - Factory function that creates a new McpServer instance.
*/
export async function startStdioServer(
createServer: () => McpServer,
): Promise<void> {
await createServer().connect(new StdioServerTransport());
}
async function main() {
if (process.argv.includes("--stdio")) {
await startStdioServer(createServer);
} else {
await startStreamableHTTPServer(createServer);
}
}
main().catch((e) => {
console.error(e);
process.exit(1);
});
