MCP Igor

A Model Context Protocol (MCP) server for Raketa DX that provides secure JavaScript code execution in a Deno sandbox environment.

Features

• Secure Execution: Runs JavaScript code in a restricted Deno sandbox with no permissions
• Temporary Isolation: Each execution runs in a temporary directory that is automatically cleaned up
• Error Handling: Provides detailed error messages and permission guidance

Installation

npm install -g @raketa-cloud/mcp-igor

Prerequisites

• Node.js 18+
• Deno installed and available in PATH

Usage

As MCP Server

Add to your MCP client configuration (e.g., Claude Desktop):

{
  "mcpServers": {
    "igor": {
      "command": "npx",
      "args": ["@raketa-cloud/mcp-igor"]
    }
  }
}

Direct Usage

Start the MCP server:

npx @raketa-cloud/mcp-igor

Available Tools

runJavaScript

Executes JavaScript code in a Deno sandbox.

Parameters:

• code (string): JavaScript code to execute

Example:

console.log("Hello from Deno!");
const result = Math.sqrt(16);
console.log(`Square root of 16 is: ${result}`);

Security

• Code runs in a completely sandboxed Deno environment
• No file system, network, or environment access
• Temporary files are created with restricted permissions (0o600)
• All temporary directories are automatically cleaned up
• Uses process umask 0o077 for additional security

Error Handling

The server provides helpful error messages for common issues:

• Permission errors with suggested Deno flags
• Syntax errors from the executed code
• Runtime errors with detailed stack traces

Development

git clone [email protected]:studioraketa/mcp-igor.git
cd mcp-igor
npm install

# Format code
npm run format:fix

# Lint code
npm run lint:fix

# Start development server
npm start

Credits

Inspired by https://github.com/bewt85/mcp-deno-sandbox. Took most of the code, removed the TS and build and simplified it to handle our cases.

License

MIT

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.