python_local MCP Server

An MCP Server that provides an interactive Python REPL (Read-Eval-Print Loop) environment.

Components

Resources

The server provides access to REPL session history:

• Custom repl:// URI scheme for accessing session history
• Each session's history can be viewed as a text/plain resource
• History shows input code and corresponding output for each execution

Tools

The server implements one tool:

• python_repl: Executes Python code in a persistent session
• Takes code (Python code to execute) and session_id as required arguments
• Maintains separate state for each session
• Supports both expressions and statements
• Captures and returns stdout/stderr output

Configuration

Install

Claude Desktop

On MacOS: ~/Library/Application\ Support/Claude/claude_desktop_config.json On Windows: %APPDATA%/Claude/claude_desktop_config.json

  "mcpServers": {
    "python_local": {
      "command": "uv",
      "args": [
        "--directory",
        "/path/to/python_local",
        "run",
        "python_local"
      ]
    }
  }

  "mcpServers": {
    "python_local": {
      "command": "uvx",
      "args": [
        "python_local"
      ]
    }
  }

Development

Building and Publishing

To prepare the package for distribution:

1. Sync dependencies and update lockfile:

uv sync

2. Build package distributions:

uv build

This will create source and wheel distributions in the dist/ directory.

3. Publish to PyPI:

uv publish

Note: You'll need to set PyPI credentials via environment variables or command flags:

• Token: --token or UV_PUBLISH_TOKEN
• Or username/password: --username/UV_PUBLISH_USERNAME and --password/UV_PUBLISH_PASSWORD

Debugging

Since MCP servers run over stdio, debugging can be challenging. For the best debugging experience, we strongly recommend using the MCP Inspector.

You can launch the MCP Inspector via npm with this command:

npx @modelcontextprotocol/inspector uv --directory /path/to/python_local run python-local

Upon launching, the Inspector will display a URL that you can access in your browser to begin debugging.