KoalaSync

_{KoalaSync is a lightweight Browser Extension and Relay Server for synchronized video playback across any website—YouTube, Twitch, and custom HTML5 players. Built with a focus on Data Sovereignty and Performance.}

🌟 Why KoalaSync?

🛡️ Security-First: Volatile RAM-based relay with built-in brute-force protection and zero-persistence architecture.
📡 Direct Logic: Manual Socket.IO wire implementation for reliable synchronization.
🛠️ Clean Build: Dependency-free extension runtime with no library overhead.
🌐 Universal: Works on any website with a <video> tag.

✨ Key Features

Global Synchronization: Synchronize Play, Pause, and Seeking on any website with a <video> tag.
Episode Auto-Sync: Perfectly sync series binges. All peers wait until everyone has loaded the next episode before starting together.
Smart Matching: Automatically highlights tabs containing matching video titles.
Dual Heartbeat Architecture: Robust session tracking that prevents ghost rooms and stale connections.
Efficient Relay: Minimal overhead WebSocket message forwarding.
Seamless Invitations: Smart links that automatically configure server and room credentials for your friends.

📂 Repository Structure

extension/: Browser Extension (Chrome & Firefox).
server/: Node.js + Socket.IO Relay Server (Containerized).
website/: Marketing landing page & Invitation Bridge.
shared/: Single Source of Truth for protocol constants.
scripts/: Automated build and synchronization utilities.
docs/: Technical deep-dives (Architecture, Sync Guide).

🚀 Quick Start

For Users (Installation)

The easiest way to install KoalaSync is to download the pre-compiled version from the Releases page.

Download the latest koalasync-chrome.zip or koalasync-firefox.zip.
Extract the file and load it as an "Unpacked Extension" in your browser's Developer Mode.

For Developers (Building)

To build the extension from source and synchronize protocol constants:

npm install
node scripts/build-extension.js

The compiled artifacts will be available in the dist/ directory.

For Self-Hosting (Docker)

Deploy your own private relay server using our official image:

# Pull the latest image
docker pull ghcr.io/shik3i/koalasync:latest

# Or use our example compose file
cp docker-compose.example.yml docker-compose.yml
docker-compose up -d

The server will be available at ws://localhost:3000. See docker-compose.example.yml for advanced configuration.

To connect your extension to a self-hosted server, open the popup → Room tab → select Custom Server → enter your server's WebSocket URL (e.g., ws://localhost:3000).

⚠️ Note: ws:// only works for localhost. If you deploy to a real domain, you must use wss:// (e.g., wss://sync.yourdomain.com). This requires a TLS-terminating reverse proxy (e.g., Caddy, Nginx, or Traefik) in front of the relay server. See Caddyfile.example for a production-ready template.

📖 Documentation & Links

PRIVACY.md: Data Handling and Privacy Policy.
CONTRIBUTING.md: How to help make KoalaSync better.
HOW_IT_WORKS.md: Step-by-step walkthrough of the complete user flow.
ARCHITECTURE.md: Deep-dive into the two-phase sync and heartbeat logic.
SECURITY.md: Disclosure policy and security practices.
Caddyfile.example: Production Caddy configuration for website and relay.

_{Built with ❤️ by Shik3i. KoalaSync is Open Source under the MIT License.}

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