MCP Calculator - AI Developer Tools Tool

Overview

MCP Calculator is an open-source sample project that demonstrates the Model Context Protocol (MCP) by exposing simple, callable tools that language models can invoke. The repository provides a working calculator tool (calculator.py) and a communication pipe (mcp_pipe.py) that handle secure WebSocket connections, real-time streaming, and automatic reconnection with exponential backoff. The project is configuration-driven: mcp_config.json lets you declare multiple local or remote MCP servers and select transport types (stdio, sse/http, http proxy) so you can run a single example tool locally or wire it into an MCP-enabled model stack. ([github.com](https://github.com/78/mcp-calculator)) Designed for developers experimenting with model-tool integrations, MCP Calculator includes an easy-to-follow example of creating tools using the FastMCP helper (mcp.tool decorator), concrete run commands, and a requirements.txt listing dependencies. The calculator example shows how to safely implement mathematical evaluation and return structured results to the calling model; the project also documents typical use cases such as email operations, knowledge-base search, remote device control, and data processing. The README and example files make it straightforward to adapt the project into custom MCP tools or to use the mcp-proxy for SSE/HTTP transports. ([github.com](https://github.com/78/mcp-calculator))

GitHub Statistics

• Stars: 324
• Forks: 136
• Contributors: 5
• Primary Language: Python
• Last Updated: 2025-11-07T23:13:08Z

Repository activity indicates modest but ongoing maintenance: the repo shows 323 stars and 135 forks and lists five contributors. There are around 20 open issues and a small number of pull requests, which suggests an active but small community of users and maintainers. Recent commits show activity in mid-to-late 2025 (multiple commits through August 2025), including README clarifications, venv/Windows fixes, and configuration improvements, indicating continued development after the initial release. The project is published under the MIT License and does not have formal GitHub releases or packages. ([github.com](https://github.com/78/mcp-calculator))

Installation

Install via pip:

git clone https://github.com/78/mcp-calculator.git

cd mcp-calculator

pip install -r requirements.txt

export MCP_ENDPOINT=<your_mcp_endpoint>  # set environment variable if needed

python mcp_pipe.py calculator.py  # run calculator example

python mcp_pipe.py  # run all configured servers from mcp_config.json

Key Features

• Calculator example (calculator.py) illustrating safe mathematical evaluation and structured results. ([github.com](https://github.com/78/mcp-calculator/blob/main/calculator.py))
• Bidirectional communication between models and tools via secure WebSocket connections. ([github.com](https://github.com/78/mcp-calculator))
• Automatic reconnection with exponential backoff to improve reliability of long-lived connections. ([github.com](https://github.com/78/mcp-calculator))
• Real-time streaming of tool output back to the calling model for interactive workflows. ([github.com](https://github.com/78/mcp-calculator))
• Config-driven server definitions using mcp_config.json for stdio, sse, and http transport types. ([github.com](https://github.com/78/mcp-calculator))
• Simple tool-creation API using FastMCP and a @mcp.tool() decorator for typed, schema-driven tool functions. ([github.com](https://github.com/78/mcp-calculator))

Community

Small but engaged community: the repo has ~323 stars, ~135 forks and 5 contributors. There are ~20 open issues and a few active pull requests; commits were made as recently as August 2025. No formal releases or published packages exist, so users typically clone and run from source. The project accepts contributions and is licensed MIT. ([github.com](https://github.com/78/mcp-calculator))

Key Information

• Category: Developer Tools
• Type: AI Developer Tools Tool