MacTap
Turns one, two or three knocks on the MacBook — or on the desk beneath it — into actions.
What it does
MacTap reads the MacBook’s motion sensor and watches for taps. One knock, two or three each map to an action: copy, paste, undo, save, play/pause, screenshot, lock, or accepting and rejecting an AI suggestion. A second layout splits left and right edges of the chassis for six slots instead of three, and per-app rules let an editor claim accept/reject/save while everything else keeps the default set.
The appeal is that the hands never leave the keyboard or the mouse, and nothing is bound to a key combination that an application might already want.
Notes
- Hardware requirement. It needs a MacBook whose accelerometer is exposed as an SPU HID device: M2 and later, or M1 Pro/Max/Ultra. The original M1 Air does not publish that report, and MacTap does not fall back to anything else. macOS 14.6 or later.
- Detection works without permissions; Accessibility is what lets a detected knock send the action.
- Sensitivity, a cooldown and ignore-while-typing are all settings, which is what keeps normal typing from triggering it.
- No Homebrew cask — the download is the project site or a GitHub release. The app itself is Developer ID signed and notarised, and a
codesign --verifyagainst the.dmgwrapper reporting unsigned is expected rather than a problem.
Alternative to
| Alternative | Type | Trade-off |
|---|---|---|
| Karabiner-Elements | Open source | Remaps keys, which still means pressing one |
| BetterTouchTool | Paid | Trackpad and Touch Bar gestures instead of knocks |
| Keyboard Maestro | Paid | Any trigger you can name, except a physical tap |
| A bare keyboard shortcut | Built in | Free, and one more combination to remember |
Install
Download from the project site, or take the
.zip from the latest GitHub release. Unzip, drag MacTap.app into /Applications, and launch it from there rather than from the disk image.