import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
import type { NextFunction, Request, Response } from "express";
import type { McpServer } from "skybridge/server";
export const mcp =
(server: McpServer) =>
async (req: Request, res: Response, next: NextFunction) => {
if (req.path !== "/mcp") {
return next();
}
if (req.method === "POST") {
try {
const transport = new StreamableHTTPServerTransport({
sessionIdGenerator: undefined,
});
res.on("close", () => {
transport.close();
});
try {
await server.connect(transport);
} catch {
await server.close();
await server.connect(transport);
}
await transport.handleRequest(req, res, req.body);
} 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,
});
}
}
} else if (req.method === "GET" || req.method === "DELETE") {
res.writeHead(405).end(
JSON.stringify({
jsonrpc: "2.0",
error: {
code: -32000,
message: "Method not allowed.",
},
id: null,
}),
);
} else {
next();
}
};
