Zlack

Zlack is a lightweight, optimized desktop wrapper for Slack, built with Tauri. It provides a native application experience with robust desktop notifications, handling deep links and window focus correctly even when minimized.

🚀 Features

• Native Desktop Notifications: Integrated directly with Windows native toast notifications.
• Unread Tray & Title Badges: The tray icon shows a red badge for unread DMs/@mentions and a blue badge for other unread messages, and the window title is prefixed with ! for unread DMs — handy if you prefer ambient indicators over toast popups.
• Custom CSS & Icon: Place zlack.css, zlack.png, zlack.ico, or zlack-taskbar.png next to the executable to customize Slack's UI and Zlack's running icons.
• Private WebView2 Runtime (optional): On Windows, Zlack uses a private webview2-runtime folder next to the executable when present, otherwise it falls back to the shared system WebView2 runtime.
• Smart Context: Extracts Team ID and Channel ID from Slack's console logs to ensure notifications take you to the exact right place.
• Background Reliability: Includes a custom rust backend to ensure clicking a notification properly restores the window from the system tray and focuses it.
• Multi-Workspace Support: Handles navigation for multiple Slack workspaces via standard webview login.
• Lightweight: Uses Tauri's minimal footprint (WebView2 on Windows) instead of a full Chromium bundle (Electron).

🛠 Tech Stack

• Frontend: Vanilla HTML/JS (Slack Web Client) + preload.js for bridge.
• Backend: Rust (Tauri) for system integration.
• Notification Engine: tauri-winrt-notification for advanced Windows Toast features (Inputs, Activation Callbacks).

📦 Installation

Download the installer for your OS:

Platform	File
Windows	Zlack_${version}_x64-setup.exe (installer) or Zlack_${version}_x64_en-US.msi
macOS	Zlack_${version}_x64.dmg

1. Run the installer.
2. Launch Zlack.
3. Log in to your Slack workspaces.

🏗 Development

Prerequisites

• Node.js
• Rust & Cargo
• Tauri CLI

Commands

Install Dependencies:

npm install

Run in Development Mode:

npm run tauri dev

Note: In dev mode, clicking notifications may not reliably restore the window due to Windows AUMID restrictions. This works fully in the built release.

Build for Production (Windows):

npm run build:dist:windows

This will compile the application and place the installer (.exe and .msi) into the dists/ folder.

Build for Production (macOS/Linux):

npm run build:dist:unix

This requires running on a Mac or Linux machine. It will generate .dmg/.app (macOS) or .deb/.AppImage (Linux) in the dists/ folder.

Optional private WebView2 runtime (Windows):

By default Zlack uses the shared, system-wide WebView2 runtime. Because that runtime is shared, allowing it through a software firewall effectively allows any app to reach the internet through it.

To use a private runtime instead, get the Fixed Version WebView2 runtime for your architecture from the WebView2 download page, extract it, and place it next to Zlack.exe as:

Zlack.exe
webview2-runtime/
  msedgewebview2.exe
  ...

If webview2-runtime/msedgewebview2.exe exists, Zlack uses it. Otherwise, it falls back to the shared system runtime.

🎨 Customization

Place optional customization files next to Zlack.exe:

Zlack.exe
zlack.css          # injected into Slack
zlack.png          # preferred custom running icon
zlack.ico          # fallback custom running icon
zlack-taskbar.png  # optional Windows taskbar-only override

The custom icon is used for the window, taskbar, and tray badge base. If zlack-taskbar.png exists, it overrides only the Windows taskbar icon. The embedded exe/installer icon remains fixed until rebuilt.

🧩 How It Works

Notification Interception

Slack's web client sends telemetry traces to /traces/v1/list_of_spans. Zlack's preload.js intercepts this network traffic:

1. Captures notification:sent spans to reliably identify the Team ID and Channel ID associated with the event.
2. Intercepts the browser's Notification API request.
3. Merges the content with the captured network context and sends it to the Rust backend.

Robust Window Restoration

Clicking a notification on Windows while an app is minimized is notoriously tricky due to OS foreground rules. Zlack solves this by:

1. Main Thread Architecture: Creates notification objects directly on the main thread to ensure proper COM listener persistence.
2. Staged Restoration: Explicitly calls set_skip_taskbar(false), unminimize(), and show() in the correct order.
3. Focus Hack: Uses a temporary "Always On Top" toggle to force the window into the foreground even if Windows tries to suppress it.

📄 License

MIT