Mathjs Calculator MCP

A simple MCP (Model Context Protocol) server that evaluates math expressions, using mathjs as the calculator backend.

What it does

• Exposes an MCP tool named calculator
• Accepts a single input: expression (string)
• Returns a formatted text result

Quick Start with npx

You can run this MCP server directly without installation using npx:

npx @liangjs/mathjs-calculator-mcp

This is useful for quickly testing or using the calculator MCP in your MCP client configuration.

Install

yarn install

Run

yarn run start

The server runs over stdio, so it's meant to be launched by an MCP-capable client/host.

Configuration

To use this MCP server in your MCP client (e.g., Claude Desktop), add it to your configuration file:

{
  "mcpServers": {
    "calculator": {
      "command": "npx",
      "args": ["@liangjs/mathjs-calculator-mcp"]
    }
  }
}

Examples

Try expressions like:

• 1 + 2 * 3
• sqrt(2)
• sin(pi / 4)
• 2 cm + 3 mm