Command Executor MCP Server

command-executor MCP Server

A Model Context Protocol server for executing pre-approved commands securely.

🎥 Demo

https://github.com/user-attachments/assets/ed763a12-b685-4e0b-b9a5-bc948a590f51

✨ Features

• Secure command execution with pre-approved command list
• Configurable allowed commands through environment variables
• Built with TypeScript and MCP SDK
• Communication via stdio for seamless integration
• Error handling and security validations
• Real-time command output streaming

🚀 Installation

Install dependencies:

Build the server:

For development with auto-rebuild:

⚙️ Configuration

🔒 Allowed Commands

By default, the following commands are allowed:

• git
• ls
• mkdir
• cd
• npm
• npx
• python

You can customize the allowed commands by setting the ALLOWED_COMMANDS environment variable:

🔌 Claude Desktop Integration

To use with Claude Desktop, add the server config:

On MacOS:

On Windows:

Configuration example:

🛡️ Security Considerations

The command-executor server implements several security measures:

1. Pre-approved Command List
   • Only explicitly allowed commands can be executed
   • Default list is restrictive and security-focused
   • Commands are validated by prefix to prevent injection
2. Command Validation
   • Command prefix validation prevents command injection
   • No shell execution for improved security
   • Environment variables are properly sanitized
3. Error Handling
   • Comprehensive error handling for unauthorized commands
   • Clear error messages for debugging
   • Failed commands don't crash the server
4. Environment Isolation
   • Server runs in its own environment
   • Environment variables can be controlled
   • Limited system access

💻 Development

📁 Project Structure

🐛 Debugging

Since MCP servers communicate over stdio, debugging can be challenging. We recommend using the MCP Inspector:

The Inspector will provide a URL to access debugging tools in your browser.

🛠️ Tool API

The server provides a single tool:

execute_command

Executes a pre-approved command.

Parameters:

• command (string, required): The command to execute

Example Request:

Example Response:

Error Response:

❌ Error Handling

The server provides detailed error messages for various scenarios:

1. Unauthorized Commands
   { "code": "InvalidParams", "message": "Command not allowed: [command]. Allowed commands: git, ls, mkdir, cd, npm, npx, python" }
2. Execution Failures
   { "content": [ { "type": "text", "text": "Command execution failed: [error message]" } ], "isError": true }

🤝 Contributing

1. Fork the repository
2. Create your feature branch
3. Commit your changes
4. Push to the branch
5. Create a new Pull Request

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.