FireFlag

Safe Firefox/Gecko flag management for users and developers

Jonathan D.A. Jewell <jonathan.jewell@open.ac.uk> :toc: macro :toclevels: 3 :icons: font :source-highlighter: rouge :experimental: :url-github: https://github.com/hyperpolymath/fireflag :url-gitlab: https://gitlab.com/hyperpolymath/fireflag :url-bitbucket: https://bitbucket.org/hyperpolymath/fireflag

Overview

FireFlag is a Firefox extension that makes about:config flags accessible and safe for everyone. Manage 105+ Firefox flags with built-in safety ratings, detailed documentation, and rollback protection.

Key Features:

• 🛡️ Safety First - Every flag rated: Safe, Moderate, Advanced, or Experimental

• 📊 Comprehensive Database - 105 flags across 8 categories

• 🔒 Privacy-First - Zero data collection, all data stored locally

• ✅ Change Tracking - Before/after values with timestamps

• 📤 Export Capability - JSON/CSV export for backup

• 🔧 DevTools Integration - Performance impact analysis

• 🔐 Granular Permissions - Only request what you need

Current Status

Version: 0.1.0
Phase: Ready for Mozilla Add-ons Submission
Completion: 99%

Component	Status	Details
Extension Package	✅ Complete	fireflag-0.1.0.xpi (120 KB, 46 files)
Flag Database	✅ Complete	105 flags with safety levels, documentation
UI Components	✅ Complete	Popup, sidebar, options, DevTools panel
Documentation	✅ Complete	Privacy policy, submission docs, test reports
Validation	✅ Complete	0 errors, 8/8 automated tests passing
Screenshots	✅ Complete	7 mockups ready for submission
Signing	⏳ Pending	Awaiting Mozilla API credentials
Submission	⏳ Pending	Ready to submit once signed

Installation

From Source (Development)

# Clone repository
git clone https://github.com/hyperpolymath/fireflag
cd fireflag

# Install dependencies (Deno required)
# No npm install needed - Deno handles dependencies

# Build extension
just build-ext

# Run in Firefox for testing
just run-ext

# Or load manually
# Firefox → about:debugging → Load Temporary Add-on
# Select: extension/web-ext-artifacts/fireflag-0.1.0.xpi

From Mozilla Add-ons (Coming Soon)

Once approved by Mozilla:

# Install from addons.mozilla.org
# Visit: https://addons.mozilla.org/firefox/addon/fireflag/

Usage

Browser Action Popup

Click the FireFlag icon in the toolbar:

• Search flags - Type to filter by name or keyword

• Filter by category - Privacy, Performance, Network, UI, Developer, Media, Accessibility, Experimental

• Filter by safety - Safe, Moderate, Advanced, Experimental

• View details - Click a flag to see full documentation

• Apply changes - Toggle or modify flag values (requires permissions)

Sidebar Panel

Open via View → Sidebars → FireFlag (or kbd:[Ctrl+Shift+Y]):

• Flags tab - View all modified flags with before/after values

• History tab - Chronological change history with timestamps

• Export - Download as JSON or CSV

Options Page

Right-click FireFlag icon → Manage Extension → Options:

• Auto-update - Enable/disable weekly database updates

• Notifications - Toggle update notifications

• Permissions - Manage granted permissions

• Clear data - Reset all changes

DevTools Panel

Press kbd:[F12] → FireFlag tab:

• Active flags - Flags affecting current page

• Performance impact - Resource usage indicators

• Recommendations - Suggested flag changes

Flag Database

Total Flags: 105 across 8 categories

Category	Count	Examples
Privacy	27	resistFingerprinting, trackingprotection, telemetry
UI	15	Tabs, downloads, appearance customization
Experimental	13	WebAssembly, WebGPU, WebXR, PWA features
Performance	7	WebRender, cache, GPU acceleration
Network	7	HTTP/3, DNS-over-HTTPS, proxy settings
Developer	7	DevTools, WebDriver, debugging
Media	7	WebRTC, autoplay, codecs, DRM
Accessibility	4	Motion, speech, assistive technologies

Safety Levels:

• Safe - No known issues, recommended for all users

• Moderate - Some caveats, read documentation first

• Advanced - For experienced users only, may affect stability

• Experimental - Unstable, may cause crashes or data loss

Privacy & Security

Zero Data Collection:

• ❌ No analytics or telemetry

• ❌ No tracking or profiling

• ❌ No personal information collected

• ❌ No remote servers (except optional database updates)

Local Storage Only:

• ✅ All data in browser.storage.local

• ✅ Stays on your device

• ✅ Fully exportable

• ✅ Completely deletable

Network Activity:

• Weekly database update checks (optional, can be disabled)

• Extension updates from Mozilla Add-ons (standard Firefox behavior)

• Nothing else

Security:

• ✅ CodeQL static analysis

• ✅ TruffleHog secret detection

• ✅ Neurosymbolic security scanning (svalin)

• ✅ SLSA Level 3 provenance (reproducible builds)

See PRIVACY.md for full privacy policy.

Development

Prerequisites

• Deno 1.40+ (package management and runtime)

• Firefox 112+ (minimum version for extension)

• ImageMagick (for screenshot generation)

• Guix or Nix (optional, for containerized builds)

Quick Start

# Install justfile runner
# Fedora: dnf install just
# Arch: pacman -S just
# macOS: brew install just

# Build extension
just build-ext

# Run in Firefox
just run-ext

# Lint extension
just lint-ext

# Run all tests
just test

Project Structure

fireflag/
├── extension/              # Extension source
│   ├── manifest.json       # Manifest V3 config
│   ├── background/         # Service worker
│   ├── popup/              # Browser action UI
│   ├── sidebar/            # Sidebar panel
│   ├── options/            # Settings page
│   ├── devtools/           # DevTools integration
│   ├── data/               # Flag database (105 flags)
│   ├── icons/              # Extension icons
│   └── lib/
│       ├── idris/          # Safety proofs (Idris2)
│       └── rescript/       # Type definitions (ReScript)
├── .containerization/      # Docker + Guix builds
├── .screenshots/           # Screenshot generation
├── scripts/                # Build and signing scripts
├── STATE.scm               # Project state tracking
├── ECOSYSTEM.scm           # Ecosystem relationships
└── META.scm                # Architecture decisions

Build System

Simple Build:

just build-ext  # Uses web-ext

Full Build Pipeline:

just full-build
# 1. Check Idris2 proofs
# 2. Build ReScript (if applicable)
# 3. Generate icons
# 4. Lint extension
# 5. Run security scans
# 6. Build .xpi package

Containerized Build:

just container-build-full
# Reproducible build with Guix + Chainguard
# Generates SLSA provenance
# SBOM (CycloneDX)

Signing & Submission

# Get Mozilla API credentials
# https://addons.mozilla.org/developers/addon/api/key/

# Sign extension
./scripts/sign-extension.sh \
  --api-key YOUR_KEY \
  --api-secret YOUR_SECRET \
  --channel listed

# Signed .xpi will be created in extension/web-ext-artifacts/

See SUBMISSION-CHECKLIST.md for complete submission guide.

Contributing

See CONTRIBUTING.md for general contribution guidelines.

See CONTRIBUTING-FLAGS.md for flag database contributions.

Areas for Contribution:

• Flag Database - Add missing flags, improve documentation

• Translations - i18n support (planned for v0.2.0)

• Testing - Browser compatibility testing (Librewolf, Waterfox, Pale Moon)

• UI/UX - Design improvements

• Documentation - User guides, tutorials, videos

Roadmap

See ROADMAP.adoc for detailed roadmap.

v0.1.0 (Current):

• ✅ 105-flag database with safety levels

• ✅ Browser action popup

• ✅ Sidebar panel with tracking

• ✅ Options page

• ✅ DevTools integration

• ✅ Privacy policy & submission docs

• ⏳ Mozilla Add-ons submission

v0.2.0 (Planned):

• Android support (Firefox for Android)

• Flag recommendations based on usage

• Import/export profiles

• Multi-profile support

• Advanced filtering (by version, impact, dependencies)

• i18n support

v1.0.0 (Future):

• WASM optimizations for flag evaluation

• ReScript compilation for type safety

• Advanced permission management

• Flag impact analysis

• Automated testing suite

License

Mozilla Public License 2.0 (MPL-2.0)

FireFlag is open source software licensed under MPL-2.0. This was chosen for compatibility with Mozilla Add-ons ecosystem requirements.

Preferred License: Palimpsest License (PMPL-1.0-or-later)
Fallback License: MPL-2.0 (for Chrome/Firefox extension stores)

See LICENSE for full text.

Links

• GitHub: {url-github}

• Issues: {url-github}/issues

• Discussions: {url-github}/discussions

• GitLab Mirror: {url-gitlab}

• Bitbucket Mirror: {url-bitbucket}

Acknowledgments

Built with:

• ReScript - Type-safe JavaScript compilation

• Idris2 - Formal verification and safety proofs

• Guix - Reproducible build environment

• Chainguard - Minimal security-focused containers

• web-ext - Mozilla’s official extension build tool

Inspired by the need for safer about:config management in Firefox and Gecko-based browsers.

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FireFlag - Safe Firefox flag management for everyone.