FoxHound is the Firefox half of an Agent Browser Bridge. It pairs with a small MCP server installed from npm so that an AI agent (Claude Code, Claude Desktop, Cursor, Antigravity, or any MCP client) can drive the browser end to end. Once both halves are running the agent can:

Open URLs, switch tabs, click and fill forms, run JavaScript in a tab, wait for elements or navigations, upload files, and screenshot the page or any single element.
Capture every HTTP request and response with bodies. Each captured request is tagged with the PwnFox container it came from. Replay any request through the same container.
Read and write cookies, localStorage, sessionStorage, IndexedDB, and Cache Storage. Snapshot every storage layer for a tab origin in one call.
Inspect what the page already runs without injecting anything new: postMessage listeners and traffic, WebSocket frames, Web Workers, service workers, route changes, errors, dangerous DOM sinks, console output.
Pause and forward requests on demand for active testing.

Privacy. Everything stays on your machine. The extension talks only to a WebSocket server bound to 127.0.0.1, signed with HMAC-SHA256 using a 32 byte secret generated locally on first install. No analytics, no telemetry, no remote code, no third party calls. Install the companion MCP server with npm install -g foxhound-mcp, then copy the configuration shown in the add on options page into your MCP client. Full setup guide and issue tracker: github.com/amrelsagaei/foxhound.

Amr Elsagaei

Published Firefox add-on:

FoxHound