Heartbeat.

A heartbeat is a scheduling loop that keeps an always-on agent ticking. The agent wakes itself on an interval, say every 15 minutes, checks its task queue, does whatever work is waiting, logs its progress, picks up anything it didn't finish, then goes dormant until the next beat.

The name fits. It's the regular pulse that keeps the agent alive without you sitting there poking it.

For builders, this is how you get an agent that runs on its own rather than only when you open a chat. The interval is the dial. Beat too often and you burn Tokens on empty checks. Beat too rarely and work sits in the queue longer than you'd like. A heartbeat usually sits on top of a Cron schedule and works alongside Scheduled tasks to keep things moving.