Voidwalker

About

Voidwalker lets AI agents (Claude, Cursor, Gemini) read and debug your browser's live state - localStorage, sessionStorage,IndexedDB, cookies, and DOM mutations - directly from your AI client.

It works by pairing a browser extension with a local MCP server running on your machine. All data stays on localhost; nothing is sent to any cloud service.

  HOW IT WORKS:
  1. Install this extension
  2. Run the Voidwalker MCP server locally (npm install -g voidwalker-mcp)
  3. Connect it to your AI client (Claude Desktop, Cursor, etc.)
  4. Ask your AI to inspect your browser state, debug storage issues, or trace mutations

  WHAT YOUR AI CAN DO:
  • Read localStorage, sessionStorage, IndexedDB, and cookies from any tab
  • Watch real-time DOM mutations as they happen
  • Diff storage state before and after user actions
  • Navigate tabs and execute storage reads/writes on your behalf

  SECURITY:
  • Token-authenticated WebSocket (256-bit token stored at ~/.voidwalker/token)
  • All traffic is local (ws://127.0.0.1:3695)
  • Sensitive keys (auth tokens, passwords, JWTs) are automatically redacted
  • Rate limiting and connection eviction built in

  PERMISSIONS EXPLAINED:
  • <all_urls>: Required to inject at document_start before page scripts load, so Storage and IndexedDB APIs can be intercepted.Without this, reads would miss keys set during page initialization.
  • storage, tabs, cookies, alarms: Used to read browser state and relay it to the local MCP server.

  No data leaves your machine. Open source on GitHub.