Cuukit install

Cover the screen,
not the work.

One click covers every connected display behind a four-digit PIN and holds the Mac awake for exactly as long as the cover is up. Whatever is running underneath keeps running.

Download for Mac

version 2.2.10  ·  107 MB  ·  Apple silicon  ·  macOS 12+
signed and notarized by Apple  ·  free, no account
sha256 bcafa0f36c8ed0f2d62cc364f213a892b2a90918b1bfedae6851546a2ff9d018

agent — run 214
› refactor the payments module and run the suite tool read src/payments/ledger.ts tool read src/payments/refund.ts tool edit src/payments/ledger.ts +64 −21 tool edit src/payments/refund.ts +18 −9 tool bash npm run typecheck tsc --noEmit clean, 0 errors tool bash npm test -- payments ledger 42 passed refund 17 passed webhooks 31 passed tool edit src/payments/index.ts +7 −2 tool bash npm run build bundling ................ 8.4s build ok › now migrate the callers tool grep createRefund\( 19 matches tool edit src/api/checkout.ts +12 −5 tool edit src/api/orders.ts +9 −4 tool edit src/jobs/reconcile.ts +21 −13 tool bash npm test 318 passed, 0 failed — 41.2s › refactor the payments module and run the suite tool read src/payments/ledger.ts tool read src/payments/refund.ts tool edit src/payments/ledger.ts +64 −21 tool edit src/payments/refund.ts +18 −9 tool bash npm run typecheck tsc --noEmit clean, 0 errors tool bash npm test -- payments ledger 42 passed refund 17 passed webhooks 31 passed tool edit src/payments/index.ts +7 −2 tool bash npm run build bundling ................ 8.4s build ok › now migrate the callers tool grep createRefund\( 19 matches tool edit src/api/checkout.ts +12 −5 tool edit src/api/orders.ts +9 −4 tool edit src/jobs/reconcile.ts +21 −13 tool bash npm test 318 passed, 0 failed — 41.2s

Screen protected

Still cooking underneath

The run does not pause. It is still moving behind the cover.

Why not just lock the Mac?

You can, and you should when what you need is security. Control-Command-Q gives you the real macOS login window, which is a stronger boundary than anything Cuukit draws.

What locking does not give you is a promise that the Mac stays awake. macOS offers to keep it running with the display off only while you are plugged in; there is no equivalent switch for battery. So a locked laptop on battery may still doze off and take a long run with it. A power setting or a caffeinate command covers that, but both are separate things to remember, and both stay switched on long after you are back.

Cuukit does the temporary version of the job: cover every display, hold the keyboard, keep the Mac awake, and let go of all three the moment you type your PIN.

For most background work, that is mainly a difference in power handling and convenience. With a live browser, the difference becomes measurable.

Locking stops the browser. Covering does not.

This is the part worth measuring rather than asserting, because it is the one place where the free workaround is actively worse.

Lock the Mac and Chrome treats every tab as hidden: animation frames stop dead and timers fall from ten ticks a second to one. Anything driving a real browser — an agent working through a page, a dashboard you left rendering — stops with it. Under Cuukit's cover the same tab kept drawing at full rate through six runs, with the browser both in front and behind.

Measured on macOS 26.5, not claimed from the spec sheet. The instrument is a page that counts its own frames, and it is here if you want to run it against your own Mac.

What it does

  • Covers every connected display from one menu bar item.
  • Holds on to the keyboard and trackpad — only the PIN keys get through, so the cover cannot be clicked or tabbed away.
  • Holds the Mac awake while the cover is up, then hands power management straight back when you unlock.
  • Stores your PIN as a salted scrypt hash, never in plain text.
  • Makes no network requests. Nothing leaves your Mac, ever.

What it is not

  • Not a replacement for your login password. It is a cover over a running session, not an account boundary.
  • Not proof against someone with real intent — a forced restart is a forced restart.
  • Not a way to pause work. Everything keeps running, including anything you would rather it did not.
  • Not a faster way back in. If your Mac has Touch ID, the login window opens with a finger; Cuukit asks for four digits.
  • Not for Intel Macs yet. Apple silicon only.

Install

  1. Open the disk image

    Drag Cuukit Screen Lid into your Applications folder, then eject the image.

  2. Launch it

    Cuukit has no Dock icon. Look for the cloche in the menu bar, then pick PIN and appearance settings… and choose four digits.

  3. Grant Accessibility

    The first time you cover the screen, macOS asks for Accessibility. That permission is what lets Cuukit hold the keyboard — without it the cover can be dismissed.