🧮 MCP Calculator Server — Build Your First MCP Tool with TypeScript

A lightweight Model Context Protocol (MCP) server built in TypeScript using the official @modelcontextprotocol/sdk. This server exposes a simple tool that performs addition of two numbers, showcasing how to build custom MCP-compatible tools.

🚀 Features

Built using the official MCP SDK
Implements a simple calculator with an add function
Written in TypeScript
Easy to extend for new MCP tools

📁 Project Structure

my-calculator/ │ ├── src/ │ └── index.ts # Main server logic ├── package.json ├── tsconfig.json └── README.md

⚙️ Setup Instructions

1. Clone the Repository

git clone https://github.com/<your-username>/mcp-calculator-server.git cd mcp-calculator-server

2. Install Dependencies

Make sure you have Node.js (v18+) and npm installed.

npm install

3. Build the Project

npm run build

4. Start the MCP Server

npm run start

You should see:

✅ MCP Calculator Server is running...

🧠 How It Works

The project uses @modelcontextprotocol/sdk to create a minimal MCP server.

import { server } from "@modelcontextprotocol/sdk/server/stdio"; import { z } from "zod"; const s = server({ name: "MCP Calculator Server", }); s.tool( "add", { a: z.number(), b: z.number(), }, async ({ a, b }) => ({ content: [{ type: "text", text: `Result: ${a + b}` }], }) ); s.start(); console.log("✅ MCP Calculator Server is running...");

This registers an add tool, which takes two numbers (a, b) and returns their sum.

🧩 Testing (Optional)

If you want to test manually:

npm run start

Then, you can connect this server to any MCP-compatible client (like Claude Desktop, ChatGPT with MCP, or other integrations).

🧱 Build Commands Reference

Command	Description
`npm run build`	Compiles TypeScript into JavaScript
`npm run start`	Starts the MCP server with ts-node
`npm install`	Installs all dependencies

🧰 Tech Stack

TypeScript
Node.js
Model Context Protocol SDK
Zod (Schema validation)

📜 License

MIT License — feel free to fork and modify.

This server cannot be installed

-

security - not tested

A

license - permissive license

-

quality - not tested

How are these scores calculated?

Resources

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