Plug in. Watch it celebrate.
PowerSnek is a tiny macOS menu-bar app that does one thing: when you plug in your charger, it draws a green comet around the edge of each display, including the MacBook notch, then gets out of the way.
It is a one-shot animation, not a background effect. There are no persistent windows, no Accessibility or Screen Recording permissions, and no ongoing GPU work after the animation finishes.
- Traces the real screen outline, notch included.
- Runs only on the battery-to-AC transition.
- Animates all connected displays.
- Can be toggled or previewed from the menu bar.
Download: get the latest PowerSnek-x.y.z.dmg from
Releases, open it, and drag
PowerSnek to Applications. Launch it, and a small power icon appears in the
menu bar. There is no Dock icon.
Build from source:
brew install xcodegen
xcodegen generate
open PowerSnek.xcodeproj # ⌘R to runClick the menu-bar icon, then open Settings...:
- Enable effect: master on/off
- Launch at login: start automatically with
SMAppService - Comet color: defaults to
#34FF6A - Laps: 1-5, default 2
- Speed: lap duration
- Preview: run the animation without unplugging
The menu also has Test Animation for a quick preview.
The app is a SwiftUI menu-bar agent with AppKit overlay windows and Core
Animation strokes. Testable logic lives in PowerSnekKit; the app target owns
the IOKit listener, overlay windows, animation, and UI.
| Piece | Responsibility |
|---|---|
PowerMonitor |
IOKit power-source notifications; fires only on battery-to-AC, with launch/wake seeded silently |
PerimeterPathBuilder |
Pure geometry to a closed CGPath outline, including notch detours |
ScreenGeometry |
Reads live NSScreen insets/notch/corner radius into the builder |
CometOverlayWindow |
One borderless, click-through, shield-level window per display |
CometAnimator |
Stacked CAShapeLayer strokes + glow, driven by an animated lineDashPhase |
AppController |
Orchestrates: on plug-in, animate every display (with per-display debounce) |
PowerSnek does not request Accessibility or Screen Recording permissions.
xcodegen generate # regenerate the project
xcodebuild build -project PowerSnek.xcodeproj -scheme PowerSnek \
-configuration Debug -derivedDataPath build CODE_SIGNING_ALLOWED=NO
xcodebuild test -project PowerSnek.xcodeproj -scheme PowerSnek \
-destination 'platform=macOS'project.ymlis the source of truth (XcodeGen); regenerate the Xcode project from it.- CI (
.github/workflows/ci.yml) builds and tests on every push and PR. - Design spec and implementation plan live under
docs/superpowers/.
PowerSnek is open source. If you think of a feature you want, issues and pull
requests are welcome. See CONTRIBUTING.md for setup,
project conventions, and PR expectations.
Tag-triggered, signed and notarized DMGs via
.github/workflows/release.yml. Signing and
notarization are secret-gated; see
scripts/release/README.md for the required
secrets. To cut a release:
git tag v0.1.0 && git push origin v0.1.0This builds a universal binary, signs it with Developer ID and Hardened Runtime, notarizes and staples it, and publishes a draft GitHub Release with the DMG and its checksum.
macOS 14+ (built and tested on macOS 26, Apple Silicon).
Apache License 2.0. See LICENSE.
