Lock, display sleep, system sleep: only one kills your agent

A black screen can mean three different things. Two of them are completely safe for a running agent.

The problemYou want to lock up and leave while an agent works — but you can't tell which kind of "off" will kill the run.

Without an appLock with ⌃⌘Q, adjust a power setting, and wrap the run in caffeinate.

What UnIdle addsOne shortcut, ⌥⌘L, that locks and lets the display sleep while the Mac keeps working — and tells you when the agent needs you.

LockSafeLogin screen on top. Everything underneath keeps running.

Display sleepSafeThe screen turns off. The Mac doesn't.

System sleepKills the runEvery process freezes until you wake it.

Lock without sleeping

Press ⌃⌘Q to lock immediately. Your session stays alive behind the login screen, and so does the agent.

Let the display sleep, not the Mac

In System Settings › Battery › Options, turn on "Prevent automatic sleeping on power adapter when the display is off". Plugged in, the screen can go dark on its normal schedule while the Mac keeps working.

On battery, there's no equivalent setting — the Mac will idle-sleep on its own schedule. Wrap the run in caffeinate -i to hold it off.

The short version

Lock freely. Let the screen sleep. Keep the system awake — and remember that closing the lid on battery is system sleep, no matter what else you've set.

Where UnIdle fits

Locked and walked away, there's one thing the built-in tools still can't handle: an agent that stops to ask "allow this command?" sits blocked behind your lock screen until you come back. UnIdle covers the whole routine:

⌥⌘L locks the Mac and lets the display sleep, while UnIdle holds system sleep off for the agent.
It lets go when the agent finishes, so the Mac sleeps normally again.
When Claude Code needs a yes, you're told right away — on your Mac, or with Pro, on your phone.

Download freePro is $12 once, with a 14-day free trial.