Calculator MCP Server

A Model Context Protocol (MCP) server built with FastMCP that exposes a calculator as a set of tools, resources, and prompts for use by an LLM client.

Tools

• Basic: add, subtract, multiply, divide

• Advanced: power, square_root, percentage

Each tool validates its inputs (division by zero, negative square roots, undefined powers, zero-denominator percentages) and returns a formatted string, and logs every successful calculation to an in-memory history.

Resources

• constants://math — pi, e, the golden ratio, and tau

• history://calculations — a chronological log of every calculation made during the current session

Prompts

• solve_equation(problem) — walks a word problem step by step, directing the model to use the calculator tools for arithmetic

• calculation_help(topic) — explains which tools/resources are relevant to a topic, with a worked example

Running it

uv sync
uv run python calculator_server.py

Point an MCP client (e.g. Claude Desktop, or an MCP inspector) at that command over stdio.