Middy middleware for Model Context Protocol server
npm install middy-mcpA Middy middleware for Model Context Protocol (MCP) server integration with AWS Lambda functions.
Middy MCP is a middleware that enables seamless integration between AWS Lambda functions and Model Context Protocol servers. It provides a convenient way to handle MCP requests and responses within your Lambda functions using the Middy middleware framework. It supports requests sent to AWS Lambda from API Gateway (both REST API / v1 and HTTP API / v2) using the Proxy integration, as well as requests sent form an ALB.
> Disclaimer: hosting your MCP server this way is only compatible with MCP clients using at least protocol version 2025-03-26.
``bash`
pnpm install middy-mcp
- Node.js >= 18.0.0
- Middy >= 6.0.0
This middleware can throw HTTP exceptions, so it can be convenient to use it in combination with the @middy/http-error-handler.
Hereafter is an exemple of a minimal Lambda function handler file. Deploy this lambda as a proxy integration on a POST route of your API Gateway and you're good to go.
`typescript
import middy from "@middy/core";
import httpErrorHandler from "@middy/http-error-handler";
import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { z } from "zod";
import mcpMiddleware from "middy-mcp";
// Create an MCP server
const server = new McpServer({
name: "Lambda hosted MCP Server",
version: "1.0.0",
});
// Add an addition tool
server.tool("add", { a: z.number(), b: z.number() }, async ({ a, b }) => ({
content: [{ type: "text", text: String(a + b) }],
}));
export const handler = middy()
.use(mcpMiddleware({ server }))
.use(httpErrorHandler());
``
This project is licensed under the MIT License - see the LICENSE file for details.
Contributions are welcome! Please feel free to open an issue or to submit a pull request 🚀!