Calculator MCP Server (Python)

A feature-rich Model Context Protocol (MCP) server for mathematical calculations, scientific functions, unit conversions, financial metrics, and statistical analysis.

Built with Python 3.10+, the official mcp SDK (FastMCP), and sympy. Supports both stdio (Claude Desktop) and sse (Claude Web / Remote HTTP Connectors) transport modes.

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🚀 Features & Exposed Tools

• evaluate_math_expression: Evaluates custom mathematical expressions safely using SymPy (e.g. 2 * (3 + 4), sqrt(144) + sin(pi / 2), log(100, 10), 5^3).
• perform_arithmetic: Basic arithmetic (add, subtract, multiply, divide) on arrays of numbers.
• scientific_calculation: Powers, roots (sqrt, cbrt), factorials, logarithms (log, ln), and trigonometric functions (sin, cos, tan).
• convert_unit: Physical unit conversions (Length, Mass/Weight, Temperature, Volume, Time).
• financial_calculator: Simple interest, Compound interest, Loan EMI calculations, and Percentages.
• calculate_statistics: Summary statistics (mean, median, mode, variance, stdev, summary).

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📦 Installation & Setup

1. Install Dependencies:

   pip install -r requirements.txt
   pip install -e .
   

2. Run Automated Unit Tests:

   pytest
   

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💻 1. Connecting to Claude Desktop (Stdio Mode)

Your claude_desktop_config.json has been automatically created at: C:\Users\ADMIN\AppData\Roaming\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "calculator": {
      "command": "C:\\Users\\ADMIN\\AppData\\Local\\Programs\\Python\\Python312\\python.exe",
      "args": [
        "-m",
        "calculator_mcp.server"
      ],
      "env": {
        "PYTHONPATH": "E:/mcp tutorials"
      }
    }
  }
}

Usage in Claude Desktop:

1. Fully exit and restart Claude Desktop.
2. Open a chat and look for the 🔨 (hammer/tools icon) at the bottom right of the message bar.
3. Ask Claude: "What is sqrt(144) + sin(pi / 2)?" or "Convert 100 degC to degF".

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🌐 2. Connecting to Claude Web & Remote Web Clients (SSE HTTP Mode)

To run the Calculator MCP as a web HTTP service (for web-based platforms, web connectors, or remote AI agents):

1. Start the SSE Web Server:

   python -m calculator_mcp.server --transport sse --port 8000
   

2. Web Client Configuration:

   {
     "mcpServers": {
       "calculator-web": {
         "serverUrl": "http://localhost:8000/sse"
       }
     }
   }
   

3. Public Tunneling for Remote Web Apps (Optional): If your web client (like remote Claude Web) is hosted outside your local network, expose port 8000 using ngrok or localtunnel:

   npx localtunnel --port 8000
   # Or using ngrok:
   ngrok http 8000
   

   Then use the generated public HTTPS URL: https://<your-subdomain>.loca.lt/sse in your Web MCP connector configuration.

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🔍 Interactive Testing via Web Interface (MCP Inspector)

You can launch the official Model Context Protocol interactive Web Inspector UI to visually test all tools in your browser:

mcp dev calculator_mcp/server.py

Or via Node:

npx @modelcontextprotocol/inspector@0.4.1 python -m calculator_mcp.server