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.