Why you need it
It says it slept. Maybe it never did.
Whether a MacBook sleeps is gated behind three locks. Close only one or two, and the UI says it's asleep while the keyboard backlight is still on.
One switch can disable sleep entirely
With it on, the whole machine never sleeps. It outranks everything — quit all the apps you want, nothing changes.
Apps can ask the system “don't let me sleep”
A browser playing video, an app with a running task — they all do this. The only way past is to quit them.
Things wake it up without telling you
One packet hitting the NIC, Bluetooth scanning in the background, a scheduled task reaching its mark — any of these can drag it out of sleep. It woke, it burned battery, and nothing on screen ever showed it.
How to use it
Before you leave: four steps.
All four happen in one window. No trips to System Settings.
Click the menu bar icon
It's a briefcase — hollow at home, solid when you're out. No Dock icon.
Click “Start Away Mode”
It lists what's blocking sleep. Close those apps yourself, or hit “Close all” — either way it moves on once they're gone.
When it says “Safe to unplug” — unplug the display
That line is telling you to act, not reporting progress. Unplug, and it takes over sleep. A few seconds later the keyboard backlight goes dark. Light off — pack up and go.
Plug back in, read the report
How many wakes, at what times, why each one happened.
When you're back
Three kinds of wake. Only one needs you.
The system log mixes three kinds of wake together. Read them blended and every single trip makes you worry. So it sorts them apart:
The wake from plugging your display back in doesn't count — you're standing right there. One false alarm and you'd never trust it again.
What it doesn't do
What it can't do, said up front.
Version 1 never succeeded once on real hardware. The UI showed everything green while the keyboard backlight stayed lit. That failure set a rule: say “can't” rather than lie. So the list below lives on the front page, not buried in an FAQ.
- Hardware key presses can't be blocked. Any key, a pressed trackpad, the power button, Touch ID — all hardware-level. Software has no say. Physical countermeasures below.
- Turning off Bluetooth kills offline Find My. If it's truly lost and whoever has it doesn't power it on, it can't be located. Your call.
- Disabling sharing services takes the machine off the LAN. If others reach this Mac over the network, skip this mode.
- Scheduled wakes are cancelled, not restored. You re-create those tasks yourself after you're back.
- No Apple Developer signing, not notarized. First launch gets blocked once — right-click → Open, then double-click normally after that.
- Move the app and its “launch at login” breaks. Re-tick that box after moving it.
Quitting apps can lose unsaved work
So it always shows the list first and waits for your nod, and the detection page spells out why each app is there. Anything that can't be closed makes it stop and ask. And the report never pretends everything succeeded.
Note: physical presses are out of software's reach
A backpack squeezing the keyboard or trackpad will wake a freshly-slept machine. That's hardware input; no app can intercept it. To stop it physically, give it a barrier: an A-panel crystal shell, or a 3D-printed cover plate over keyboard and trackpad. Skip this and accidental wakes will happen.
What this software does solve are the other two things: preventing “fake sleep” — the UI says asleep, backlight still glowing — and pushing it back to sleep after an accidental wake (Enhanced Mode, on by default: five minutes awake with no one around and it acts).
Open source
All the source is on GitHub.
MIT licensed. Build it yourself, or read exactly what it changes on your system first. A tool that edits your sleep settings has no business hiding its code.
Download
Three minutes to install.
Download, drag into Applications
Inside the DMG is the app. Drag it to the Applications folder on the left. Done.
First launch: right-click → Open
No developer signature, so macOS will block it once. Right-click the icon → Open → confirm. Normal double-click afterwards.
One password, exactly once
Changing system sleep settings needs admin rights — enter it once, never asked again. Notifications are optional; denying them costs you nothing but a banner.
b0c959493e138bcfd051612ddf9f11640b284d0aa74c4813c5c634e816441bb4The first-launch guide ships inside the DMG too. Stuck? See the FAQ or the first-launch notes (in Chinese).
Interface
Just these screens.
The app UI is currently in Chinese — the screenshots are the real thing.
FAQ
A few more common ones.
Everything's on the FAQ page.
Does it snoop on my stuff?
No. Accessibility, Screen Recording, Automation, Full Disk Access — it asks for none of the heavy permissions.
Just two things: one admin password (to install the background service, never asked again) and notifications (you can deny).
State and reports live on your machine under ~/Library/Application Support/HeadlessKnightMaster/. Nothing gets uploaded anywhere.
How does it know whether the machine was woken?
It records a timestamp when you leave, then reads pmset -g log from that point on, sorting every wake into dark, notification, and real wakes.
App killed mid-trip, system reboot, log rotation — none of it matters, the anchor is on disk.
What if I don't have an external display?
It still works. Unplug detection keys on display ID, not count — it copes even with the built-in display physically removed.
Prefer not to unplug at all? The unplug page has “Sleep now, without unplugging” — one click, no waiting.
How do I uninstall?
Drag the app to the Trash, then run this to clean up the background service and state files:
sudo rm -f /Library/PrivilegedHelperTools/com.headlessknight.helper \
/Library/LaunchDaemons/com.headlessknight.helper.plist
sudo rm -rf ~/Library/Application\ Support/HeadlessKnightMaster
sudo rm -f ~/Library/LaunchAgents/com.headlessknight.app.plistBluetooth and sharing services are restored the moment you tap “Done” in the app. If you never did, just turn Bluetooth back on and re-enable the services by hand.
Does it cost anything?
Free. No ads, no in-app purchases, no telemetry, no account — and it never goes online.
Stop guessing whether it slept.
One click before you leave. A straight answer when you're back.
Free Download 1.6