What Zeph is

Zeph is a small connected device: a screen you read at a glance, buttons under your thumb, a microphone and a speaker. Press a button, speak, done.

Inside, it runs ZephOS — an operating system we build for devices this size. On your Mac, the companion holds the other end of the link, and that is how an agent reaches the screen in your hand.

The device

Its home is a strip of cards. Each card is a glance: the face of one app, a fact or two you can read in a second. Tap the face and you are in the room behind it. The strip holds eight.

Every button carries a few gestures — a tap, a double tap, a hold. Each gesture is a slot, and you decide what goes in it — hold to talk, and the words land at your cursor. Which buttons a device has is part of that device, and the companion shows you the ones on yours.

ZephOS

ZephOS is the software on the device, and it is one image: a UI toolkit, the shell that owns the strip of glances, and a sandbox for apps you did not write. They are flashed together, and the companion updates them together, over the air.

What is on the device

One firmware image. Flashed together, updated together.

The app sandboxA WebAssembly runtime. Apps arrive over the wire, one at a time, and run inside it.

The glance shellThe strip of faces, the rooms behind them, and one router every gesture and button funnels into.

ZephUIA screen is a tree of widgets. The renderer walks the tree and draws it.

The kernelThreads, drivers, storage, Bluetooth, USB.

The boardAn ESP32-S3 with an AMOLED display.

Nothing on the device draws pixels directly. An app, a system screen, or your Mac describes a tree of widgets, and one renderer turns that description into what you see. That is why an agent can hand the device a screen: it writes the same tree everything else writes.

The companion

The companion is a desktop app for macOS. Close the window and it keeps running in the menu bar, holding:

• the link to your device, over Bluetooth or USB, encrypted either way;
• your audio — the routing engine, and a virtual microphone that lets any app on your Mac hear the device;
• your workflows — a trigger, a few steps, an effect: hold the button, speak, and the transcript is typed at the caret;
• your extensions — the speech and model providers a workflow routes to, running on your machine or behind a vendor's key;
• an MCP server on localhost.

The MCP server is how an agent reaches the device's screen. Claude Code — or anything else that speaks MCP — connects to it, and once you approve the client it can push a screen to the device, subscribe to what you tap, and notify you.

How an agent reaches the device

An agentClaude Code, or any MCP client on your Mac.

a tool call

The companionAn MCP server on localhost. You approve the client on first connect.

a widget tree

ZephUIOn the device. The renderer walks the tree.

pixels

The screen in your handWhere the agent's screen arrives.

Where the hardware is

Zeph Pulse is the first device we make. It is coming, and you cannot buy one yet.

What you can do today is run all of this on an off-the-shelf development board. ZephOS runs on boards you can buy now, and the companion flashes one over USB-C — give it a few minutes. Same operating system, same companion, same apps, same MCP server. The device is what changes.