0002: Agents get their own Wayland seat

• Status: accepted
• Date: 2026-09-26

Context

"Humans and agents co-exist" has to mean something concrete on a desktop. If an agent injects input into the user's seat, the user cannot work while the agent works: the pointer moves, focus jumps, the clipboard is clobbered. Codex on macOS solves this with private APIs. Wayland has standard protocols for it.

Decision

Every agent task runs against its own seat, created with ext-transient-seat-v1, with virtual pointer and keyboard bound to that seat. Per-window capture uses ext-image-copy-capture-v1. The agent's cursor is rendered distinctly. The user can freeze, take over or reveal the agent's work at any time.

Consequences

• Slate targets Wayland only. X11 is not a supported target.
• Slate targets compositors that implement these protocols: wlroots-based today. GNOME and KDE are not supported until they do.
• SlateOS ships and, where needed, patches its own compositor.
• The protocols are standard, so slate-desktop should work on any conforming compositor with reduced integration.