MCP Calculator Server (Python)

A simple Model Context Protocol (MCP) server implementation in Python that provides basic calculator functionality.

Installation

Install the required dependencies:

pip install -r requirements.txt

Or install the MCP Python SDK directly:

pip install mcp>=1.18.0

Usage

Running the Server

The server is designed to be used by MCP clients (like Claude Desktop). To start the server:

python mcp_calculator_server.py

Note: When run directly in a terminal, you'll see JSON-RPC validation errors. This is normal behavior - the server is waiting for properly formatted MCP client messages.

Testing the Functions

To test that the calculator functions work correctly:

python test_calculator.py

Troubleshooting

Import Errors

If you see ModuleNotFoundError: No module named 'mcp', install the MCP Python SDK:

pip install mcp>=1.18.0

JSON-RPC Errors When Running Directly

Errors like "Invalid JSON: EOF while parsing a value" when running the server directly are expected. The server needs MCP client messages, not direct terminal input.