Multi

Multi lets macOS users bundle a set of web pages into a single native‑looking application. Each app is defined by a JSON file that lists the URLs to load, optional titles, and per‑tab customizations such as JavaScript, CSS, cookies, basic‑auth credentials, or a custom user‑agent string. The configuration also controls window behavior, notification handling, always‑on‑top status, and how external links are opened.

The tool provides a command‑line interface for creating and updating these apps, and the resulting binaries integrate with macOS features like native notifications, file‑upload dialogs, drag‑and‑drop URL opening, and find‑in‑page. Users can choose between tabbed windows or separate floating windows, and can enable automatic reloading for sites that disconnect.

Intended for individuals who want lightweight, dedicated desktop wrappers for web services—such as a Slack clone—Multi is distributed as a Homebrew cask or a downloadable DMG and runs on stable macOS releases.