🐍 FastMCP Python REPL Server

Give any AI assistant the power to execute Python — via MCP.

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✨ What Is This?

A production-ready MCP (Model Context Protocol) server that exposes a Python REPL as an AI tool.

Plug it into Claude, Cursor, or any MCP-compatible AI — and watch it execute real Python code on demand.

You / AI Agent  →  MCP Tool Call  →  This Server  →  Live Python Output  →  Back to AI

🔴 Live Demo: This server is actively running and connected to Claude.ai as a custom tool.

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🚀 Features

• ⚡ One tool, infinite power — run_python executes any Python code and returns output
• 🌐 Cloud-ready — deploy to Render, Railway, or any platform in minutes
• 🔌 Plug & Play — works with Claude, Cursor, and any MCP-compatible client
• 🧰 Built on FastMCP — the fastest way to build MCP servers in Python
• 📦 Minimal setup — 3 dependencies, ~10 lines of core code

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🛠️ Quick Start

1. Clone & Install

git clone https://github.com/Pokemon455/fastmcp-python-repl-server.git
cd fastmcp-python-repl-server
pip install -r requirements.txt

2. Run Locally

python main.py

Server starts at: http://localhost:10000/mcp

3. Connect to Claude Desktop

Add this to your claude_desktop_config.json:

{
  "mcpServers": {
    "python-repl": {
      "url": "http://localhost:10000/mcp",
      "transport": "streamable-http"
    }
  }
}

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☁️ Deploy on Render (Free)

1. Fork this repo
2. Go to render.com → New Web Service
3. Connect your GitHub repo
4. Set start command: python main.py
5. Done! Your MCP server is live 🎉

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📦 Tech Stack

Package	Purpose
fastmcp	MCP server framework
langchain-experimental	Python REPL execution
uvicorn	Lightning-fast ASGI server

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🔧 MCP Tool Reference

run_python(code: str) → str

Executes any Python code string and returns the output.

Example:

# Input
code = "print(sum([1, 2, 3, 4, 5]))"

# Output
"15"

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🗺️ Roadmap

• Python REPL via MCP
• Render/Railway deployment support
• API key authentication
• Sandboxed execution environment
• Support for file I/O & pip installs
• Docker support

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🤝 Contributing

PRs are welcome! If you have ideas to make this better — open an issue or submit a pull request.

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👤 Author

Pokemon455 — AI/ML & MCP Developer 🔗 GitHub

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