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js-sandbox MCP Server: Secure Isolation & Enterprise Control - MCP Implementation

js-sandbox MCP Server: Secure Isolation & Enterprise Control

js-sandbox MCP Server: Mirror, secure, and scale JavaScript execution flawlessly. Future-proof isolation meets enterprise-grade control—built for real-world resilience.

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About js-sandbox MCP Server

What is js-sandbox MCP Server: Secure Isolation & Enterprise Control?

This server acts as a secure gateway for executing JavaScript code in tightly controlled environments. Built on the Model Context Protocol (MCP), it ensures enterprise-grade isolation by running code in sandboxed processes with strict resource boundaries. Think of it as a digital safety zone where even untrusted scripts can’t escape their designated playground.

How to use js-sandbox MCP Server: Secure Isolation & Enterprise Control?

Getting started is straightforward: start by installing dependencies with npm install, then build the server using npm run build. For active development, enable auto-rebuild mode via npm run watch. To integrate with Claude Desktop, update your config file with the server path. The most critical step? Always validate inputs and monitor execution limits to maintain security posture.

js-sandbox MCP Server Features

Key Features of js-sandbox MCP Server: Secure Isolation & Enterprise Control?

  • Execution Safety: Mandatory timeout (100-30,000ms) and memory (1MB-100MB) caps prevent resource exhaustion attacks
  • Code Containment: Each script runs in fully isolated processes with no access to host system resources
  • Enterprise Flexibility: Configurable parameters let admins balance security constraints with operational needs
  • Debugging Power: Use the MCP Inspector tool (link) to troubleshoot through browser-based visualizations

Use cases of js-sandbox MCP Server: Secure Isolation & Enterprise Control?

Perfect for scenarios requiring strict code confinement:

  • Executing untrusted third-party scripts in SaaS platforms
  • Running customer-provided plugins in enterprise applications
  • Automating tasks with sandboxed headless browsers
  • Testing suspicious code samples in security research

js-sandbox MCP Server FAQ

FAQ from js-sandbox MCP Server: Secure Isolation & Enterprise Control?

How does it prevent code injection attacks?
All code executes in memory-limited VMs with network and filesystem access completely disabled
Can I customize timeout/memory limits per request?
Yes - both parameters are configurable through API calls when invoking execute_js
What logging capabilities exist?
Full execution traces are captured by default, including error stacks and resource utilization metrics
How do I diagnose communication issues?
The MCP Inspector provides real-time traffic analysis and protocol validation tools

Content

js-sandbox MCP Server

A Model Context Protocol server that provides a secure JavaScript execution environment.

Features

Tools

  • execute_js - Executes JavaScript code in an isolated environment
    • Parameters:
      • code (required): JavaScript code to execute
      • timeout (optional): Maximum execution time in milliseconds (100-30000ms)
      • memory (optional): Memory limit in bytes (1MB-100MB)
    • Returns the result of code execution

Security

  • Isolated code execution in a controlled environment
  • Configurable execution time and memory limits
  • Protection against malicious code

Development

Install dependencies:

npm install

Build the server:

npm run build

Development mode with auto-rebuild:

npm run watch

Installation

To use with Claude Desktop, add the server configuration:

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

{
  "mcpServers": {
    "js-sandbox": {
      "command": "/path/to/js-sandbox/build/index.js"
    }
  }
}

Debugging

Since MCP servers communicate over stdio, debugging can be challenging. We recommend using MCP Inspector, which is available as:

npm run inspector

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

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