1. Set up your project 

mkdir cursor-mcp
cd cursor-mcp
npm init -y
npm pkg set type=module

2. Install dependencies 

npm install @modelcontextprotocol/sdk

3. Create index.js 

import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import { z } from "zod";

const server = new McpServer({
  name: "Hello World",
  version: "1.0.0"
});

server.tool("add",
  { a: z.number(), b: z.number() },
  async ({ a, b }) => ({
    content: [{ type: "text", text: String(a + b) }]
  })
);

const transport = new StdioServerTransport();
await server.connect(transport);

4. Add to Cursor

Go to Settings, MCP, and add new MCP server.

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The command is node /absolute/path/to/your/index.js. For example node /Users/andyrewlee/mcp-server/index.js.

5. Trigger your MCP by asking Cursor to add 24 and 81

In Agent mode prompt 8 + 24 and watch the add tool in your MCP get triggered.

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