Support

Need help with Cairn - Metrics? Start with the answers below. If they don't solve it, email developer@startoni.com and say which device and OS version you're using.

Getting started

  1. On a Mac, open Cairn and press ⌘, to open Settings.
  2. Make sure the Mac is signed in to iCloud. "Collect This Mac's Stats" is on by default, and you can check it in Settings.
  3. macOS may ask you to allow "Cairn Helper" in System Settings > General > Login Items. It keeps the Mac collecting after you close Cairn. Until you allow it, the Mac collects while Cairn's window is open.
  4. Within about a minute the Mac appears as a card with CPU, memory, disk and battery gauges. Open it for the detail screen and history graphs.
  5. On your iPhone or iPad, sign in to the same iCloud account. Your Mac shows up in the list.

Frequently asked questions

The app is empty.

Cairn shows computers that are collecting. Open Cairn on a Mac, check that "Collect This Mac's Stats" is on in Settings, and make sure every device is signed in to the same iCloud account. If your Mac isn't in the list, tap "Collect This Mac's Stats" on the This Mac card.

A Mac says Offline.

Stats update about once a minute. A Mac is marked Offline after a few minutes without a report. It has to be awake and collecting, with Cairn open or its background item running.

The history graphs are empty.

A new computer starts with a single dot, and each device then adds a point every 5 minutes. Once a computer has two hours of history saved, the graph switches to the saved 15-minute history.

Why is there a gap in a graph?

The computer wasn't reporting, for example because it was asleep or off. "Long gaps with no data" in Settings squeezes a long gap narrow, with its length in a label, or draws it to scale. It only changes that device.

How do I stop Cairn running in the background?

On a Mac, open Settings and change "Keep Collecting When Closed" to Menu Bar or Off. To stop a Mac publishing at all, turn off "Collect This Mac's Stats".

How do I share a computer?

Open the computer's detail screen and use the two-people button to open its Sharing screen. Invite someone from there. They open the link and the computer appears in their app. The same screen lists everyone it's shared with, and removing a person ends their access. They can also leave with "Stop Watching".

What does a shared computer reveal?

Its stats, history, name and hardware model. The serial number, IP address and startup disk name stay hidden unless you turn each one on for that computer on its Sharing screen.

Which systems are supported?

macOS 27 or iOS 27 or later.

Privacy

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