Voidwalker

Zero-state local MCP for browser storage

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.