Python REPL MCP Server

This is a fork of hdresearch/mcp-python, a Python REPL server for MCP protocol.

This MCP server provides a Python REPL (Read-Eval-Print Loop) as a tool. It allows execution of Python code through the MCP protocol with a persistent session.

Setup

No setup needed! The project uses uv for dependency management.

Environment Variables

The server supports .env file for environment variables management. Create a .env file in the root directory to store your environment variables. These variables will be automatically loaded and accessible in your Python REPL session using:

import os

# Access environment variables
my_var = os.environ.get('MY_VARIABLE')
# or
my_var = os.getenv('MY_VARIABLE')

Running the Server

Simply run:

uv run src/python_repl/server.py

Usage with Claude Desktop

Add this configuration to your Claude Desktop config file:

{
  "mcpServers": {
    "python-repl": {
      "command": "uv",
      "args": [
        "--directory",
        "/absolute/path/to/python-repl-server",
        "run",
        "mcp_python"
      ]
    }
  }
}

The server provides three tools:

1. execute_python: Execute Python code with persistent variables

   • code: The Python code to execute
   • reset: Optional boolean to reset the session

2. list_variables: Show all variables in the current session

3. install_package: Install a package from pypi

Examples

Set a variable:

a = 42

Use the variable:

print(f"The value is {a}")

List all variables:

# Use the list_variables tool

Reset the session:

# Use execute_python with reset=true

Contributing

Contributions are welcome! Please feel free to submit a Pull Request. Here are some ways you can contribute:

• Report bugs
• Suggest new features
• Improve documentation
• Add test cases
• Submit code improvements

Before submitting a PR, please ensure:

1. Your code follows the existing style
2. You've updated documentation as needed
3. Maybe write some tests?

For major changes, please open an issue first to discuss what you would like to change.