The MCP-REPL server provides a comprehensive JavaScript/TypeScript execution and code analysis environment with advanced tooling for debugging, search, and transformation.

• Execute JavaScript/TypeScript code directly with Node.js or Deno, supporting ESM imports, CommonJS compatibility, dynamic imports, type checking, and full access to native APIs including web requests

• Debug and test hypotheses through iterative code execution with structured debugging approaches and batch operations for complex workflows

• Perform semantic code search with natural language queries, metadata extraction, and AST-aware chunking across project directories with configurable folders, ignores, and extensions

• Conduct AST-based pattern matching using ast-grep for searching, replacing, linting, and analyzing code structures with support for dry runs and interactive mode

• Transform and validate code with pattern-based replacements and YAML-defined rule validation for linting purposes

• Analyze AST structures with debugging capabilities for query analysis, pattern understanding, and full tree context viewing

• Work across multiple environments including Claude Code, Cursor, GitHub Copilot, and VS Code with flexible configuration options

Provides a secure JavaScript REPL (Read-Eval-Print-Loop) environment to execute code snippets with error handling, memory management, and output formatting.

Enables secure access to Node.js built-in modules and execution of JavaScript code in a sandboxed VM context with working directory support.

Allows running the REPL directly via npx without installation or installing it globally through npm for repeated usage.

1. Click on "Install Server".

2. Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state.

3. In the chat, type @ followed by the MCP server name and your instructions, e.g., "@MCP-REPL execute this JavaScript: console.log('Hello, World!');"

That's it! The server will respond to your query, and you can continue using it as needed.

Here is a step-by-step guide with screenshots.