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hyperpolymath

Claude for Gecko

Unofficial Claude AI assistant for Firefox and Gecko-based browsers

image::https://img.shields.io/badge/Firefox-115%2B-orange.svg[Firefox 115+] image::https://img.shields.io/badge/Manifest-V3-green.svg[Manifest V3]

Overview

Claude for Gecko brings Claude AI to browsers that the official extension doesn’t support:

• Firefox

• LibreWolf

• Mullvad Browser

• Tor Browser

• Waterfox

• Floorp

This is an unofficial extension that uses the Anthropic API directly. It is not affiliated with or endorsed by Anthropic.

Features

• Popup Chat - Quick access to Claude from any page

• Context Menu - Right-click selected text to: Explain Summarize

  • Translate ** Ask custom questions

• Overlay Responses - See Claude’s answers without leaving the page

• Conversation History - Maintains context within a session

• Model Selection - Choose between Sonnet, Opus, or Haiku

Requirements

• Firefox 115+ (or compatible Gecko-based browser)

• Anthropic API key (Get one here)

Installation

From Source (Developer Mode)

[source,bash]

git clone https://github.com/hyperpolymath/claude-gecko-browser-extension.git cd claude-gecko-browser-extension —-

1. Open Firefox and navigate to about:debugging . Click “This Firefox” in the sidebar . Click “Load Temporary Add-on…” . Select the manifest.json file from the cloned directory

From Firefox Add-ons (Coming Soon)

The extension will be submitted to Firefox Add-ons once stable.

Configuration

1. Click the extension icon in your toolbar . Click the ⚙️ settings button . Enter your Anthropic API key . (Optional) Select your preferred model . (Optional) Add a custom system prompt

Usage

Popup Chat

1. Click the Claude icon in your toolbar . Type your message and press Enter (or click Send) . Shift+Enter for multi-line input

Context Menu

1. Select text on any webpage . Right-click to open the context menu . Choose a Claude action: “Ask Claude to explain” “Ask Claude to summarize” “Ask Claude to translate” “Ask Claude about this…”

Keyboard Shortcuts

[cols=“1,2”] |=== | Shortcut | Action

Enter
Send message

Shift+Enter
New line in input

Escape
Close overlay

== Privacy * Your API key is stored locally in browser storage * Messages are sent directly to Anthropic’s API * No data is collected or transmitted to third parties * No analytics or tracking == Licensing === Legal License This project is licensed under the Palimpsest-MPL License v1.0 (PMPL-1.0) - see LICENSE for details. You are free to use, modify, and distribute this software. === Philosophical Companion: Palimpsest License We encourage adopters to also consider the principles of the Palimpsest License - a philosophical manifesto for building technology that serves humanity’s long-term flourishing. The Palimpsest License is not a legal document but a commitment to: * Building on the work of others with gratitude * Leaving the codebase better than you found it * Considering the ethical implications of your changes * Passing knowledge forward to future contributors See docs/PALIMPSEST.adoc for the full text. == Development === Project Structure == [source] claude-gecko-browser-extension/ ├── manifest.json # Extension manifest (MV3) ├── src/ │ ├── background/ │ │ └── background.js # Service worker, API calls │ ├── content/ │ │ ├── content.js # Page overlay injection │ │ └── content.css # Overlay styles │ ├── popup/ │ │ ├── popup.html # Main popup UI │ │ ├── popup.js # Popup logic │ │ ├── popup.css # Popup styles │ │ ├── options.html # Settings page │ │ ├── options.js # Settings logic │ │ └── options.css # Settings styles │ └── icons/ │ └── icon-*.png # Extension icons ├── docs/ │ └── PALIMPSEST.adoc # Philosophical license ├── LICENSE # Palimpsest-MPL License v1.0 (PMPL-1.0) ├── README.adoc # This file └── STATE.scm # Project state checkpoint —- === Building No build step required - the extension runs directly from source. === Testing . Make changes to the source files . Go to about:debugging → “This Firefox” . Click “Reload” on the extension . Test your changes == Contributing Contributions welcome! Please: . Fork the repository . Create a feature branch . Make your changes . Submit a pull request == Disclaimer This is an unofficial extension. “Claude” is a trademark of Anthropic, PBC. This project is not affiliated with, endorsed by, or sponsored by Anthropic. == See Also * Anthropic API Documentation * Firefox Extension Workshop * MDN WebExtensions Guide