Time Machine’s “Manually” setting still exists in macOS 27, but only as a protected system setting. Changing it takes administrator rights and Full Disk Access, so Cadence does it through a small helper that you approve once.
Why Cadence asks for an administrator password
When you click Set Up Cadence, macOS asks for an administrator password to register the Cadence helper, a background service that starts with your Mac. You’re asked once. Updates to Cadence don’t ask again: when the installed helper is older than the app, Cadence restarts it with one click and no password.
The helper does three things only:
- switches Time Machine between Manual and Automatic (the same switch as
tmutil disableandtmutil enable), - starts and stops backups and reads their progress with
tmutil, - deletes leftover local snapshots, if you turn that on, keeping the ones Time Machine needs.
It never reads the contents of your backups, and Cadence makes no network calls. The app and the helper check each other’s code signature, so only the signed Cadence app can control the helper.
Grant Full Disk Access
Reveal the helper
Open the Cadence menu and click Reveal Helper in the setup banner. A Finder window opens with
cadence-helperselected. It lives inside the app, atCadence.app/Contents/MacOS/cadence-helper.Open Full Disk Access
Open System Settings›Privacy & Security›Full Disk Access.
Add the helper and switch it on
Drag
cadence-helperfrom the Finder into the list, then make sure its switch is on. macOS may ask for your password to change the list.
Cadence checks for the permission by trying to read Time Machine’s settings file, which is exactly the access it needs, so the banner updates as soon as access works.
If the banner still asks for access
- Make sure the item you switched on is
cadence-helper, not Cadence itself. - If you moved Cadence after granting access, remove the old entry with the minus button and add the helper again from the app in Applications.
- Quit and reopen Cadence from the Applications folder.