Choose your surface
Three ways to build on Zeph, ranked by how ready they are — and where to start.
There are three ways to extend Zeph. They differ in how much they ship to the device and how ready they are today. Start with the first — it needs no build step and no SDK, and works right now from your own environment.
Agents over MCP
Your agent registers itself and becomes a first-class app on the device — push_screen draws a live UI, notify blocks and hands you the user's answer, a button press wakes your agent. Nothing compiles, nothing installs to flash. This is the surface an outsider can use today.
Device apps (WASM)
Code that lives on the device, sandboxed, installed to flash — it keeps running with the companion asleep. Rust, no_std, wasm32, rendered through the real device renderer without hardware. The full dev loop exists; the guest SDK is not published yet, so you copy an example directory rather than run a scaffold, and distribution is first-party.
Skills
Instruction content that teaches someone else's agent — Claude Code, Cursor, Claude Desktop — how to drive a device running ZephOS. It installs into their skills directory. The catalog is the unit, and it is published.
Which one
If it must keep working with your Mac closed, it is a device app. If it is your agent's face on the device, it is agents over MCP. If you are teaching a tool you already use to drive the device, it is a skill.
Agents over MCP
Device apps: Quickstart
Build a skill
The public SDK, toolchain, and authoring studio are coming.