LUCE

LUCE is a small macOS menu bar app with a single job: let you clean your keyboard without accidentally pressing keys or triggering system shortcuts while you do it. Clicking "Lock Keyboard" in the menu bar blocks all keyboard input at the system level, including media keys for volume and brightness. Your mouse and trackpad still work, so you can click "Unlock" when you are done.

The app is written in Swift with no third-party dependencies. It lives in the menu bar (the strip of icons at the top right of a Mac screen) and shows a small floating panel anchored to the top of the display when activated. The panel stays on top of other windows so the Unlock button is always reachable.

A safety check runs before locking: LUCE reads the current screen brightness and refuses to lock if it is below 20%, because a dark screen would make the Unlock button hard to see. The app also installs a crash-safe handler so the keyboard is always restored even if the app quits unexpectedly.

Visual customization includes four color themes for the panel background (Default, Rare Jade, Deep Ocean, and Floral) and a choice of menu bar icon from Apple's built-in SF Symbols set. An automatic update check in the About panel compares the installed version against the latest GitHub release.

Installation is a standard drag-to-Applications from a downloaded disk image. macOS may block first launch because the app is not distributed through the App Store; the README includes a one-line Terminal command to clear that flag. The app requires macOS 14 (Sonoma) or later and requests Accessibility permission, which is needed to intercept keyboard events system-wide.