How do I get notified when an agent finishes if I’m away from the machine?

Route the finish signal off the desk. Claude Code and Codex both fire a Stop hook at the end of a turn, and the hook runs any command you point it at, so a Slack webhook, an SMS API call, or a push service reaches you wherever you are. A say or a desktop banner only works if you are sitting there.

Hooks tell you something finished, not which project, so give each gem or repo its own hook message before you rely on it. crystl for iPhone does this natively: it pushes activity and approval requests to your phone, over the local network for free or from anywhere on Guild. For the on-screen version at your desk, see how do I get notified when an agent needs me or finishes.