| name | anti-sleep |
| description | Keep a Mac awake with caffeinate during long builds, downloads, or supervised automation runs. |
| category | operations |
| risk | critical |
| source | community |
| source_repo | davidondrej/skills |
| source_type | community |
| date_added | 2026-07-07 |
| author | davidondrej |
| tags | ["macos","caffeinate","operations"] |
| tools | ["claude","codex"] |
| license | MIT |
| license_source | https://github.com/davidondrej/skills/blob/main/LICENSE |
Anti-Sleep (macOS caffeinate)
When to Use
- Use when the user wants the Mac to stay awake during a long supervised task.
- Use when a build, download, or automation run should not be interrupted by sleep.
Keep the Mac awake using the built-in caffeinate command. No install needed.
Quick start — the standard command
caffeinate -d -i -t 7200
Duration is -t <seconds>: 2h = 7200, 7h = 25200, overnight (9h) = 32400.
Aggressiveness levels
| Flags | Effect |
|---|
-i | prevents idle system sleep only (screen may still dim/lock) |
-d | prevents display sleep (screen stays on) |
-d -i | default choice — screen on + system awake |
-d -i -s | adds -s: prevents sleep even on AC power semantics; -s only works when plugged in |
-u -t 1 | simulates user activity — wakes the display right now |
Default to -d -i -t <seconds> unless the user says otherwise.
Tie to a process instead of a timer
caffeinate -d -i -w <PID>
caffeinate -i npm run build
Run it in a visible terminal (cmux pane)
Prefer running it in the user's own terminal pane so it's visible and easy to Ctrl+C. In cmux (read the cmux skill first if interacting with panes):
cmux send --surface surface:<N> "caffeinate -d -i -t 25200\n"
Otherwise run it as a background Bash task. Never block your own foreground shell with it.
Verify and monitor
pgrep -fl caffeinate
ps -o etime= -p <PID>
pmset -g assertions | grep -i deny
Gotcha: caffeinate prints nothing and holds the prompt — it looks "stuck" or like Enter wasn't pressed. It isn't stuck. Verify with pgrep, not by looking at the terminal.
Expiry: with -t it exits silently when time runs out — no notification. If the user asks "is it still on?" after hours, check pgrep first; it may simply have expired.
Keyboard backlight
caffeinate cannot keep the keyboard backlight on — it has its own inactivity timer with no CLI/API on Apple Silicon (researched 2026-07). Fix is manual, one-time: System Settings > Keyboard > "Turn keyboard backlight off after inactivity" > Never.
Stop early
pkill -f "caffeinate -d -i"
After starting: confirm to the user the PID, the flags, and the wall-clock time it will expire.
Limitations
- Adapted from
davidondrej/skills; verify local paths, tools, credentials, and agent features before acting.
- For commands, remote access, scheduling, browser automation, or file-changing workflows, get explicit user approval and confirm the target environment first.