The companion
A desktop app for macOS that keeps running in the menu bar after you close the window.
The companion is a desktop application for macOS. Close its window and Zeph keeps running in the menu bar, holding the device link, audio, your workflows and the MCP server.
The menu-bar item shows the connected device, its battery and its link. It holds Disconnect, updates, a way back into the window, and Quit.
The window
One window, one sidebar, six sections:
| Section | What lives there |
|---|---|
| Devices | Every device you own. Connect, set up, flash, recover. Each device opens a profile: overview, glances, apps, settings, storage, firmware, debug. |
| Assistant | A chat with a model you configured. |
| Workflows | Every workflow, and the editor: a trigger, then a list of steps you drag into the order you want. |
| Library | Extensions: discover, apps, integrations, skills, updates. |
| Settings | General, audio routing, MCP clients, privacy, diagnostics. |
| About | Version, channel, updates. |
The part that never sleeps
Closing the window does not quit Zeph. The window is a surface onto a program that goes on running without it.
Close the window; Zeph keeps running
The window is a view; this is the program. It does not need the window open to do its job.
- The link to your devices — Bluetooth and USB, reconnected automatically, encrypted either way.
- Audio — the routing engine, the microphone level, and the virtual microphone that lets any app hear your device.
- The workflow engine — triggers, steps, and the effects they produce.
- The Library — your extensions, and the runtime that hosts the companion half of your apps.
- An MCP server on localhost, which is how agents reach the device.
- Updates — for the app, the firmware, the audio driver, and everything in the Library.
Your device stays usable while you work in something else, and Claude Code and other agents reach the device's screen with no window open.
macOS
The companion is a macOS desktop app, and macOS is the only build today.
What's tied to macOS, and what isn't
The parts closest to the system are written for macOS: the virtual microphone is a CoreAudio plug-in, typing at your cursor goes through CGEvent, and the audio routing engine compiles on macOS only. The core underneath is portable — the zeph command-line tool is built from exactly the same Rust crate — so nothing about the device or the protocol is Mac-specific.