mcp-server

Currency Converter MCP Server

A simple Model Context Protocol (MCP) server that exposes a convert_currency tool, allowing MCP-compatible clients (like Claude Desktop) to convert an amount from one currency to another.

Note: This is a learning/demo project. The conversion rate is currently a hardcoded placeholder (1.2) and not a live exchange rate.

Features

• 🔌 Built with the official @modelcontextprotocol/sdk
• 🪙 Exposes one tool: convert_currency
• 📡 Communicates over stdio transport
• ✅ Input validation via Zod

Prerequisites

• Node.js v18 or higher
• npm (comes with Node.js)

Installation

git clone https://github.com/nehamangal/mcp-server.git
cd mcp-server
npm install

Usage

Run the server directly

node index.js

The server communicates over stdio, so running it standalone in a terminal won't show much — you'll just see:

MCP server running on stdio

It's meant to be launched by an MCP client, not run interactively.

Connect it to Claude Desktop

Add the server to your Claude Desktop config file:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "currency-converter": {
      "command": "node",
      "args": ["/absolute/path/to/your/index.js"]
    }
  }
}

Restart Claude Desktop, and the convert_currency tool should appear in the tools list.

Tool Reference

convert_currency

Converts an amount from one currency to another.

Parameter	Type	Description
amount	number	The amount of money to convert
fromCurrency	string	Currency code to convert from (e.g., USD)
toCurrency	string	Currency code to convert to (e.g., EUR)

Example call:

{
  "amount": 100,
  "fromCurrency": "USD",
  "toCurrency": "EUR"
}

Example response:

100 USD is approximately 120.00 EUR

Project Structure

.
├── index.js         # MCP server entry point
├── package.json
└── README.md