Reading on one device must clear the others
Aliases: badge sync · notification dismissal · clear on read
What it is
The mail is opened on the computer; the phone badge still shows 1, and the same row sits on the watch face. The job is done; other devices still treat it as open. Read on one device, clear everywhere: banners, list rows, and badges should vanish with “handled,” not wait for a swipe on every machine. This is not the same layer as ringing fewer times at arrival. Arrival is interrupt count; clearing is residue after handling. Mail, chat, and calendar invites all carry this expectation.
Why it happens
Notification Center is a local queue per device. Opening, swiping, or marking read inside the app changes that queue by default. Other devices never hear that the matter closed, so residue becomes a second interruption: still on the lock screen, still badging someone into content they already saw. The close signal is tiny and should ride the same fast path as read state; if the notification pipe and the content-sync pipe are separate, the body can be read while the banner remains. People treat the badge as a to-do count; residue systematically inflates workload and trains them to ignore badges. Clearing has to cover three surfaces: a live banner, the history row in Notification Center, and the app-icon badge. Clearing one leaves the other two to pull people back.
Where it stops holding
A notice meant to be finished later on another device (a title glanced at on the computer, the body saved for the tablet at night) must not globally clear on a preview; preview and open are different. On a shared account or household device, one person’s read must not clear another’s. An offline device will miss the close signal; on reconnect it should fetch the closed set before painting the lock screen, so handled rows do not light up again. OS-level unread (SMS, missed calls) may be counted by the system; an in-app checkmark that cannot touch the system badge has to use the platform’s read API.
Applying it
- Map “open the detail,” “mark read,” and “swipe away” onto one cross-device close event, and on other ends drop the banner, the list row, and the badge together.
- Do not treat a preview (a lock-screen glance, a banner that appeared briefly) as a close; only entering the object or an explicit dismiss should send clearing.
- On reconnect, fetch the closed set before rendering lock screen and badges, so handled items do not flash.
- Verify by opening a badged mail and a calendar invite on the computer, then immediately checking the phone lock screen, Notification Center, and mail badge. All three surfaces should drop the matching items within seconds. Then swipe one row away only in the phone’s Notification Center; the computer badge should drop too. As a control, expand a banner without entering the detail: that item should remain on the other devices.