Claudezilla

Browser automation for Claude Code that runs on Firefox — for systems where Chrome is unavailable, unwelcome, or policy-prohibited.

The only Firefox-native MCP server for Claude Code. Navigate, automate, screenshot, and extract data on any system that runs Firefox — no Chrome dependency, no Google infrastructure.

Claudezilla.com

Why Claudezilla?

Anthropic's official browser tool requires Chrome. If you're on a system where Chrome is not available — or not acceptable — Claudezilla gives Claude Code the same browser automation capabilities through Firefox.

• Linux-native — Works with the Firefox that ships on Debian, Fedora, RHEL, Ubuntu, and every major distro. No Google repository required.
• Zero telemetry — All communication runs through a local Unix socket. No data leaves your machine. No Google account, no Chrome sync, no phone-home.
• Hardened environments — Built for Tails, Whonix, Qubes OS, air-gapped networks, and enterprise Linux where package policy prohibits Chrome.
• Multi-agent safe — 12-tab shared pool with 128-bit agent IDs, ownership tracking, and screenshot mutex. Multiple Claude sessions coexist safely.
• Full feature parity — Click, type, scroll, screenshot, evaluate JS, access DevTools console and network. Same capabilities, different browser.

Quick Start

1. Install the extension

Install from Firefox Add-ons

2. Install the native host

git clone https://github.com/boot-industries/claudezilla.git
cd claudezilla

# macOS
./install/install-macos.sh

# Linux
./install/install-linux.sh

The installer automatically:

• Installs the native messaging host
• Runs npm install for MCP dependencies
• Configures Claude Code MCP settings (~/.claude/mcp.json)

No manual config required — restart Claude Code and you're ready.

What Can Claude Do?

Capability	Description
Browse	Open URLs, navigate pages, manage tabs
Read	Extract text, get page structure, accessibility tree
Interact	Click buttons, fill forms, press keys, scroll
Screenshot	Capture pages (JPEG, configurable quality)
Consent	Auto-dismiss cookie/GDPR consent dialogs
Wait	Handle SPAs and dynamic content
Focus Loops	Persistent iterative tasks until completion

Support Development

Claudezilla is free and open source. You can support its development with a one-time donation or monthly sponsorship:

• Click the ☕ Buy Me a Coffee button on the welcome page after first install
• Or use the ☕ Support this project link in the extension popup
• Donations are processed securely through Stripe

See STRIPE_SETUP.md for deployment and configuration details.

Example Usage

Once connected, Claude can use commands like:

Claude, open https://example.com and take a screenshot
Claude, fill in the search box with "Firefox automation" and click submit
Claude, get all the links on this page

Available Tools

Browser Control

• firefox_create_window — Open URL in browser
• firefox_navigate — Navigate current tab to a URL
• firefox_get_content — Read page text (50K char limit)
• firefox_click — Click element by CSS selector
• firefox_type — Type into input field
• firefox_press_key — Keyboard events (Enter, Tab, shortcuts)
• firefox_screenshot — Capture viewport (supports annotated mode)
• firefox_get_tabs / firefox_close_tab — Manage tabs

Configuration

• firefox_activate — Load tool categories on demand (lazy loading saves ~6K tokens)
• firefox_set_config — Set domain allowlist, consent auto-dismiss, and session config
• firefox_set_private_mode — Toggle private/regular browsing
• firefox_handle_consent — Dismiss cookie/GDPR consent dialogs

Focus Loops

• firefox_start_loop — Start persistent iteration with prompt and max iterations
• firefox_stop_loop — Stop active loop manually
• firefox_loop_status — Check iteration count and state

Page Analysis

• firefox_get_page_state — Structured data (headings, links, buttons, diff support)
• firefox_get_accessibility_snapshot — Semantic tree (screen reader view)
• firefox_get_element_info — Element attributes and styles
• firefox_wait_for — Wait for element, text, or URL pattern
• firefox_scroll — Scroll to element or position

Diagnostics

• firefox_diagnose — Check connection health, socket status, and troubleshoot issues

Requirements

• Firefox 91+
• Node.js 18+
• Claude Code CLI

Privacy & Security

Claudezilla is designed with security in mind:

• Command whitelist — Only predefined actions allowed
• Local only — Communication via Unix socket (no network exposure)
• Tab isolation — Each Claude session owns its tabs
• URL validation — Blocks dangerous schemes (javascript:, data:)
• Supply chain hardened — ignore-scripts=true, pinned dependencies, pnpm strict isolation, SHA-pinned CI actions, timing-safe auth

Works in both regular and private Firefox windows. Tab navigation respects ownership — Claude can only navigate tabs it created.

See SECURITY.md for the full security model.

Architecture

Claude Code ←→ MCP Server ←→ Unix Socket ←→ Native Host ←→ Firefox Extension

The extension uses Firefox's Native Messaging to communicate with a local Node.js process, which exposes tools via the Model Context Protocol.

Contributing

Issues and PRs welcome. See CLAUDE.md for development notes.

License

MIT

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Author: Chris Lyons — boot.industries