A tiny menu-bar app that stops your Mac from falling asleep. One click. Filled cup = awake. ☕

The story (or: why this exists at all)

I wanted the classic coffee-cup-in-the-menu-bar thing. Easy, right? Except my work laptop's MDM had other plans:

1. Tried KeepingYouAwake → blocked.
2. Tried the classic Caffeine app → blocked.
3. Tried dropping a LaunchAgent → turns out the MDM had made ~/Library/LaunchAgents root-owned. Blocked.

At that point it was personal. Downloaded apps get a quarantine flag and have to clear notarization + an endpoint-management allowlist — but a binary you compile locally has no quarantine flag and isn't a pre-built app the MDM recognizes. So I got bored, opened a .swift file, and wrote my own in ~120 lines.

CaffeineOSS wasn't a real project. It's not on Homebrew, it wasn't on GitHub, the name didn't exist. I just built it because I was bored and the corporate firewall made me angry. Now it's here. ☕

What it actually does

Under the hood it's the same trick Apple's own /usr/bin/caffeinate uses — a single public IOKit call:

IOPMAssertionCreateWithName(
    kIOPMAssertionTypePreventUserIdleDisplaySleep as CFString,
    IOPMAssertionLevel(kIOPMAssertionLevelOn),
    "CaffeineOSS keeping the Mac awake" as CFString,
    &assertionID
)

That's it. It asks the OS power manager to prevent user-idle display/system sleep while active, and releases the assertion when you toggle off. No kernel extensions, no private APIs, no special entitlements, no daemons phoning home.

• 🟤 Outline cup = sleep allowed (normal)
• ☕ Filled cup = staying awake
• ⏱ Timed modes — awake for 30 min / 1 h / 2 h / 5 h, then auto-off
• 🪶 Featherweight — one Swift file, zero dependencies, no Dock icon (menu-bar only)

Install (build it yourself — that's the whole point)

You need the Xcode Command Line Tools (xcode-select --install). Then:

git clone https://github.com/kuberwastaken/caffeineOSS.git
cd caffeineOSS
./build.sh
open CaffeineOSS.app

build.sh compiles main.swift, wraps it in a proper .app bundle, and ad-hoc signs it locally — so there's no quarantine flag for an MDM/Gatekeeper to choke on.

Start at login (survives reboots)

The clean way is a LaunchAgent — but if your MDM has locked down ~/Library/LaunchAgents (mine had), use the per-user Login Items list instead, which doesn't need that directory:

osascript -e 'tell application "System Events" to make login item at end with properties {path:"'$PWD'/CaffeineOSS.app", hidden:true, name:"CaffeineOSS"}'

Verify it took:

osascript -e 'tell application "System Events" to get name of every login item'

You can also do this by hand in System Settings → General → Login Items → +.

Uninstall

# stop it
osascript -e 'quit app "CaffeineOSS"'
# remove from login items
osascript -e 'tell application "System Events" to delete login item "CaffeineOSS"'
# delete the build
rm -rf CaffeineOSS.app

No-install fallback

If even a locally-built app gets blocked, macOS ships the original. Zero install, zero app:

caffeinate -d        # keep display awake until Ctrl-C
caffeinate -t 3600   # awake for 1 hour
caffeinate make      # awake until `make` finishes

CaffeineOSS is really just a friendly coffee cup glued on top of that idea.

Project layout

caffeineOSS/
├── main.swift        # the entire app (~120 lines)
├── build.sh          # compile → .app bundle → ad-hoc sign
├── assets/
│   └── banner.svg    # the cup up top
└── README.md

License

MIT — see LICENSE. Do whatever you want with it. ☕

_{Built because I was bored and the corporate firewall made me angry.}