MCP Server Node

🚀 Creating an MCP Server with Node.js

This project demonstrates how to create an MCP (Model Context Protocol) server using Node.js, offering two fundamental tools. One tool, add, takes two numbers and returns their sum. The other tool, getApiKey, retrieves an API key from environment variables (via the API_KEY variable).

🚀 Quick Start

Prerequisites

• Node.js: Version 20 or higher is required.

Installation

1. Clone the repository

   git clone <repository_url>
   cd <repository_directory>
   

2. Install dependencies You can install project dependencies in one of two ways: Option 1: Install using the existing package.json Simply run:

   npm install
   

   Option 2: Manually install dependencies If you prefer, you can delete the existing package.json and manually install the required packages:

   npm install @modelcontextprotocol/typescript-sdk zod
   

   Then copy the following code into a new index.ts file:

   import { McpServer } from "@modelcontextprotocol/typescript-sdk";
   import { ServerTransportStdio } from "@modelcontextprotocol/typescript-sdk";
   
   // Define the schema for the add tool
   const addSchema = {
     inputs: {
       a: "number",
       b: "number"
     },
     output: "string"
   };
   
   // Define the schema for the getApiKey tool
   const getApiKeySchema = {
     inputs: {},
     output: "string"
   };
   
   const server = new McpServer({
     name: "node-mcp-server",
     version: "1.0.0",
     transport: new ServerTransportStdio()
   });
   
   // Register the add tool
   server.registerTool("add", {
     schema: addSchema,
     async run(inputs) {
       return inputs.a + inputs.b;
     }
   });
   
   // Register the getApiKey tool
   server.registerTool("getApiKey", {
     schema: getApiKeySchema,
     async run() {
       return process.env.API_KEY || "no-api-key";
     }
   });
   
   // Start the server
   server.start();
   

Configuration

Create a server.json file in the project root directory and add the following content:

{
  "name": "node-mcp-server",
  "version": "1.0.0",
  "tools": {
    "add": {
      "description": "Calculate the sum of two numbers",
      "inputs": {
        "a": {
          "type": "number",
          "required": true
        },
        "b": {
          "type": "number",
          "required": true
        }
      },
      "output": "string"
    },
    "getApiKey": {
      "description": "Get the API key",
      "inputs": {},
      "output": "string"
    }
  }
}

Usage

1. Set the environment variable API_KEY:

   export API_KEY=your_api_key_here
   

2. Run the server:

   node index.ts
   

3. Now, you can test the tools using the following commands:

   mcp-client add --a 10 --b 20
   mcp-client getApiKey
   

✨ Features

• MCP Integration: Exposes functionality to LLM-based IDEs.
• Addition Tool: Accepts two numeric parameters and returns their sum.
• Environment Variable Retrieval: Demonstrates how to load example environment variables from a configuration file.
• Input Validation: Uses Zod for schema validation.
• Standard I/O Transport: Connects via StdioServerTransport for integration with development environments.

📚 Documentation

What is MCP?

The Model Context Protocol (MCP) provides a standardized way to integrate custom tools into AI-assisted development environments. With MCP, you can define tools that perform specific tasks—such as retrieving external data, validating code, or enforcing coding standards—and the AI assistant in the IDE can automatically call these tools based on context. This helps improve developer productivity, ensure consistent quality, and streamline workflows.

References & Resources

• Model Context Protocol: TypeScript SDK
• Use Your Own MCP on Cursor in 5 Minutes
• Introduction to the Model Context Protocol

📄 License

This project is licensed under the MIT License.