Calculator MCP Server

calculator-mcp is an MCP (Model Context Protocol) server that exposes 16 arithmetic operations as callable tools for use by LLMs within agentic applications. It contains no mathematical logic of its own. Instead, each tool is a thin synchronous wrapper that logs its arguments and delegates execution to the open-source calculator-lib package published on PyPI as calculator-lib-rubens.

Features

16 calculator functions exposed through an MCP server for consumption by AI agentic programs:

Two-operand operations: add, subtract, multiply, divide, power, nth_root, modulo, floor_divide
Single-operand operations: sqrt, absolute, floor, ceil, log10, ln, exp
Rounding: round_number (with configurable decimal places)

The following are the supported MCP JSON-RPC 2.0 methods:

Lifecycle Methods: initialize, notifications/initialized
Tools Methods: tools/list, tools/call
Resources Methods: resources/list, resources/templates/list, resources/read
Prompts Methods: prompts/list, prompts/get

The following MCP protocols are supported, selected by the client per request:

Legacy MCP (Version: 2025-06-18): initialize handshake and Mcp-Session-Id session
Modern MCP (Version: 2026-07-28): no handshake or session

Unsupported Features

Unsupported JSON-RPC methods:

Logging & Progress Utilities (e.g. notifications/progress)
Server-to-Client calls (e.g. sampling/createMessage, elicitation/create, roots/list)

AI Disclaimer

This project includes code and documentation created with the assistance of AI tools. For details on usage, limits, and review practices, please see the AI Disclaimer.

Prerequisites

Python 3.14+
pip

Installation

Install using pip

pip install calculator-mcp-rubens

Confirm the installed version matches the latest GitHub release at calculator-mcp/releases

calculator-mcp --version
pip show calculator-mcp-rubens

Uninstall

pip uninstall calculator-mcp-rubens
pip cache purge

Configuration

Copy the file config.yaml to ${HOME}/cfg/calculator-mcp/config.yaml.

export CALCULATORMCP_CONFIG="${HOME}/cfg/calculator-mcp/config.yaml"

Usage

calculator-mcp

Health check

curl -v http://localhost:8080/health
# Expect: OK

To stop, press Ctrl+C in the running terminal

License

The project is licensed under the MIT License.

Links

Author: Rubens Gomes

Metadata

Release files for calculator-mcp-rubens 0.0.39

For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.

Source distribution (sdist)

Source distribution for calculator-mcp-rubens 0.0.39
File	Size	Uploaded
calculator_mcp_rubens-0.0.39.tar.gz	12.5 kB	Oct 2, 2026	Details

Built distribution (wheel)

Table of built distributions (wheels) for calculator-mcp-rubens 0.0.39
File	Interpreter	ABI	Platform	Reset
calculator_mcp_rubens-0.0.39-py3-none-any.whl 19.2 kB Oct 2, 2026	Python 3	none	any	Details

Total release size: 31.7 kB

Release files / calculator_mcp_rubens-0.0.39.tar.gz

Download URL	calculator_mcp_rubens-0.0.39.tar.gz
Size	12.5 kB
Tags	Source
SHA-256 checksum How to use checksums	`4b0614d46b304a9e87af72429775127d21c10c71a059161cb03f3409db6f4890`
BLAKE2b-256 checksum How to use checksums	`daa5546574631e02ed2068932e808a9949e83c0a2dff7c5ef1d2fc2d4eefcf75`
Upload date	Oct 2, 2026
Uploaded using Trusted Publishing? What is trusted publishing?	No
Uploaded via	`poetry/2.4.3 CPython/3.14.7 Linux/6.17.0-1022-azure`

Release files / calculator_mcp_rubens-0.0.39-py3-none-any.whl

Download URL	calculator_mcp_rubens-0.0.39-py3-none-any.whl
Size	19.2 kB
Tags	Python 3
SHA-256 checksum How to use checksums	`9c924975edaa89acf3801d8d9d85a1e24834a9ab61b653f379bc27dda402c94c`
BLAKE2b-256 checksum How to use checksums	`42ae3ae79d8ec71f82920a8e977cd1c25c7bd2fd657a058f7a3b9b42706a08a7`
Upload date	Oct 2, 2026
Uploaded using Trusted Publishing? What is trusted publishing?	No
Uploaded via	`poetry/2.4.3 CPython/3.14.7 Linux/6.17.0-1022-azure`