BrowSync

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BrowSync is a macOS native app that makes Safari, Chrome, Arc, Edge, and Brave work together. It unifies your browsing experience through a local WebSocket daemon, browser extensions, intelligent URL routing rules, and cross-browser data synchronization.

Important

Privacy First by Design BrowSync is built on a strict privacy-first architecture. All synchronization and URL routing happen entirely locally on your device via a local WebSocket daemon. Your browsing data (history, bookmarks, cookies) never leaves your machine, and no external servers or cloud services are involved.

🚀 Key Features

• Intelligent URL Routing: Register BrowSync as your default macOS browser. Its powerful rule engine automatically directs links to your preferred browser based on domain, URL patterns, query strings, source application, time of day, or Focus mode.
• Cross-Browser Synchronization: Seamlessly sync Cookies, LocalStorage, sessionStorage, Tab states, and Bookmarks across Safari and Chromium-based browsers (Chrome, Arc, Edge, Brave).
• Flexible Sync Strategies: Choose the synchronization logic that fits your workflow:
  • Unidirectional (Master-slave)
  • Last-Write-Wins (based on access time)
  • Bidirectional Merging
• Granular Control: Manage sync scope with whitelist/blacklist rules. Apply per-site policy overrides for ultimate customization.
• Local & Secure: All communication happens entirely on your machine via a local WebSocket daemon (ws://127.0.0.1:62333). No external servers are involved.
• Native macOS Experience: Built with SwiftUI. Supports Dark/Light themes, Menu Bar integration, Focus Mode, and Launch at Login.

🛠 Installation & Setup

1. Requirements

Tool	Version
macOS	14.0+
Xcode	15.0+
Swift	5.10+
Homebrew	Latest
XcodeGen	2.40+

2. Quick Start

# 1. Clone the repo
git clone https://github.com/chentao1006/browsync.git
cd browsync

# 2. Run the setup script
chmod +x setup.sh
./setup.sh

# 3. Open the generated project
open BrowSync.xcodeproj

Then in Xcode:

1. Select the BrowSync target → Signing & Capabilities
2. Set your Development Team
3. Press ⌘R to build and run

3. Loading the Chromium Extension

For Chrome, Arc, Edge, or Brave:

1. Open the browser → go to chrome://extensions/
2. Enable Developer Mode (top-right toggle)
3. Click Load Unpacked
4. Select the ChromiumExtension/ folder
5. The BrowSync extension icon will appear in the toolbar. Safari users can enable the extension directly in Safari Settings.

🔍 Architecture & Protocol

System Architecture

Safari Extension           Chrome / Arc / Edge / Brave Extension
      │                                    │
      └──────────── WebSocket ─────────────┘
                         │
                  BrowSync Daemon
              ws://127.0.0.1:62333
                         │
                   BrowSync App
              (macOS native, SwiftUI)

Directory Structure

BrowSync/
├── BrowSync/                   # macOS App (Swift/SwiftUI)
│   ├── App/                    # Entry point, AppState
│   ├── Views/                  # 5-tab UI
│   ├── Core/                   # DaemonServer, BrowserScanner, BrowserLauncher
│   ├── Models/                 # Data models (Browser, Rule, SyncModels, WSMessage)
│   ├── Services/               # RulesEngine, SyncService, SettingsService
│   └── Resources/              # Info.plist, Localizable.strings (en + zh-Hans)
│
├── BrowSyncExtension/          # Safari Web Extension target
│   ├── SafariWebExtensionHandler.swift
│   └── Resources/
│       ├── manifest.json
│       ├── background.js       # WebSocket client, bookmark/cookie/tab sync
│       ├── content.js          # localStorage/sessionStorage proxy
│       ├── popup.html
│       └── popup.js
│
├── ChromiumExtension/          # Shared MV3 extension (Chrome/Arc/Edge/Brave)
│   ├── manifest.json
│   ├── background/
│   │   └── service-worker.js   # Same logic as Safari background.js
│   ├── content/
│   │   └── content-script.js
│   ├── popup/
│   │   ├── popup.html
│   │   └── popup.js
│   └── _locales/
│       ├── en/messages.json
│       └── zh_CN/messages.json
│
├── project.yml                 # XcodeGen configuration
├── BrowSync.entitlements       # App entitlements (Sandbox: NO)
└── setup.sh                    # One-command project setup

WebSocket Protocol

All browser extensions connect to the BrowSync daemon at ws://127.0.0.1:62333.

• Registration: { "type": "register", "browser": "chrome", "instanceId": "chrome-main" }
• Heartbeat (every 30s): { "type": "heartbeat" }
• Sync:

{
  "type": "sync",
  "browser": "safari",
  "site": "chatgpt.com",
  "category": "bookmarks",
  "payload": { "kind": "bookmarks", "bookmarks": [...] },
  "messageId": "uuid",
  "timestamp": 1234567890
}

📁 Data Directory & Identifiers

BrowSync stores its data locally in your Application Support folder:

~/Library/Application Support/BrowSync/
├── sites/          # Per-site sync state
├── bookmarks/      # Synced bookmark snapshots
├── history/        # History (when enabled)
├── logs/           # sync.log
└── settings.json   # All app settings

Bundle IDs:

• App: com.ct106.browsync
• Safari Extension: com.ct106.browsync.extension
• App Group: group.com.ct106.browsync

🎯 Feature Status (MVP)

Feature	Status
Browser detection & extension status	✅
WebSocket Daemon	✅
URL routing rules & Default browser handling	✅
Bookmark sync	✅
localStorage & sessionStorage sync	✅
Cookie sync	✅
Tab state sync	✅
Safari & Chromium Extensions	✅
Focus Mode (data + UI)	✅
Dark/Light/System theme & EN/zh-Hans localization	✅
Automatic Sync & iCloud Sync	🔜 PRO
History sync	⚠️ Off by default

⚠️ Important Notes

• Default Browser: To utilize the URL routing feature, BrowSync must be set as your default system browser in macOS Settings.
• History Sync: History synchronization is currently disabled by default for performance and privacy considerations.

🛡 License

© 2026 BrowSync. All rights reserved.