Direct Node.js REPL Executor

Simplified JavaScript Execution Environment

A streamlined direct Node.js execution environment that enables seamless code execution with full support for:

• ESM Modules - Native import/export syntax
• Dynamic Imports - Full support for await import()
• CommonJS compatibility - Works with require() through createRequire
• Native Node.js API access - Direct access to all Node.js features

Configuration

For Cursor, update your .cursor/mcp.json configuration:

{
  "mcpServers": {
    "mcp-repl": {
      "command": "node",
      "args": [
        "path/to/direct-node-executor.js", "path/to/your/project"
      ],
      "env": {},
      "disabled": false,
      "autoApprove": ["execute"]
    }
  }
}

Features

• Direct Node.js Execution: Runs code directly in Node.js without VM sandboxing
• Full Module Support: Seamless support for ESM and CommonJS modules
• Real-time Feedback: Get immediate results from code execution
• Enhanced Debugging: Clean output with proper error handling
• Simple Architecture: Streamlined implementation with minimal complexity
• File System Access: Full access to the file system for real testing

Implementation Details

This implementation:

1. Creates temporary .mjs files for each execution
2. Runs the code directly with Node.js in a separate process
3. Captures all console output and execution results
4. Cleans up temporary files automatically
5. Returns standardized results to the MCP client

Usage Examples

// Dynamic imports
const fs = await import('fs/promises');
const path = await import('path');

// Reading files
const content = await fs.readFile('package.json', 'utf8');
console.log(JSON.parse(content));

// Using path utilities
console.log(path.join('folder', 'file.txt'));