Implement AlarmKit alarms and countdown timers for iOS and iPadOS with Lock Screen, Dynamic Island, StandBy, and paired Apple Watch system UI. Covers AlarmManager scheduling, AlarmAttributes and AlarmPresentation, system Stop and AlarmButton secondary actions, authorization, state observation, count

AlarmKit Schedule prominent alarms and countdown timers that surface on the Lock Screen, Dynamic Island, StandBy, and a paired Apple Watch when the alarm fires. AlarmKit requires iOS 26+ / iPadOS 26+. Alarms can break through Focus and Silent mode. AlarmKit uses ActivityKit data models for its Live Activity, but the firing alert is system managed alarm UI, not a general custom notification UI surface. Custom UI belongs only to countdown and paused Live Activity states rendered by a Widget Extension with the same AlarmAttributes<Metadata and AlarmPresentationState used when scheduling. See [references/alarmkit patterns.md](references/alarmkit patterns.md) for complete code patterns including authorization, scheduling, countdown timers, snooze handling, and widget setup. Contents [Workflow]( workflow) [Authorization]( authorization) [Alarm vs Timer Decision]( alarm vs timer decision) [Scheduling Alarms]( scheduling alarms) [Countdown Timers]( countdown timers) [Alarm States]( alarm states) [AlarmAttributes and AlarmPresentation]( alarmattributes and alarmpresentation) [AlarmButton]( alarmbutton) [Live Activity Integration]( live activity integration) [Common Mistakes]( common mistakes) [Review Checklist]( review checklist) [References]( references) Workflow 1. Create a new alarm or timer 1. Add NSAlarmKitUsageDescription to Info.plist with a user facing string. 2. Request authorization with AlarmManager.shared.requestAuthorization() when the app can explain the value, or handle the first schedule system prompt. 3. If authorization is .denied or not .authorized , show recovery UI instead of scheduling. 4. Configure AlarmPresentation (alert, countdown, paused states). 5. Create AlarmAttributes with the presentation, optional metadata, and tint color. 6. Build an AlarmManager.AlarmConfiguration (.alarm or .timer). 7. Schedule with AlarmManager.shared.schedule(id:configuration:) . 8. Observe alarmManager.alarmUpdates and confirm the scheduled ID reaches the expected state. 9. If using countdown, add a Widget Extension target with an ActivityConfiguration for the same AlarmAttributes<Metadata type. 2. Review existing alarm code Run through the Review Checklist at the end of this document. Authorization AlarmKit requires user authorization. Request early when the app can explain the value, or let AlarmKit prompt automatically on first schedule. If authorization is not granted after the explicit or automatic prompt, alarms are not scheduled and will not alert. Alarm vs Timer Decision Feature Alarm ( .alarm ) Timer ( .timer ) Fires at Specific time (schedule) After duration elapses Countdown UI Optional Always shown Recurring Yes (weekly days) No Use case Wake up, scheduled reminders Cooking, workout intervals Use .alarm(schedule:...) when firing at a clock time. Use .timer(duration:...) when firing after a duration from now. Scheduling Alarms Alarm.Schedule Use .fixed(date) for a one time absolute date or .relative for a local clock time with .never or .weekly repetition. Load [Recurring Alarm Patterns](references/alarmkit patterns.md recurring alarm patterns) for daily, weekday, weekend, and fixed date variants. Schedule and Configure For an authorization gated function and metadata bearing variant, load [Complete Alarm Scheduling Flow](references/alarmkit patterns.md complete alarm scheduling flow). stopIntent and secondaryIntent default to nil . Omit stopIntent for AlarmKit's standard system Stop behavior; provide it only when Stop must run app cleanup, custom stop behavior, or other side effects. Omit secondaryIntent for ordinary Snooze/Repeat with secondaryButtonBehavior: .countdown and Alarm.CountdownDuration.postAlert ; provide it only for .custom secondary behavior or app cleanup/custom behavior. Alarm State Transitions cancel(id:) remove the alarm completely, including repeating alarms pause(id:) pause a counting down alarm; throws from other states resume(id:) resume a paused alarm; throws from other states stop(id:) stop the alarm; one shot alarms are removed, repeating alarms reschedule countdown(id:) restart countdown from alerting state (snooze); throws from other states Countdown Timers Timers fire after a duration and always show a countdown UI. Use Alarm.CountdownDuration to control pre alert and post alert durations. CountdownDuration Alarm.CountdownDuration controls the visible countdown phases: preAlert seconds to count down before the alarm fires (the main countdown) postAlert seconds for a repeat/snooze countdown after the alarm fires Load [Complete Countdown Timer Flow](references/alarmkit patterns.md complete countdown timer flow) for the timer factory, pause/resume presentation, metadata, and scheduling gate. Alarm States Each Alarm has a state property reflecting its current lifecycle position. State Meaning .scheduled Scheduled and ready to alert at the appropriate time .countdown Actively counting down (timer or pre alert phase) .paused Countdown paused by user or app .alerting Alarm is firing sound playing, UI prominent Observing State Changes AlarmManager.shared.alarms is a throwing getter for the current daemon snapshot. Use try , and either propagate the error or wrap launch refresh in do/catch before relying on the snapshot. Observe alarmUpdates rather than maintaining an independent lifecycle. Load [State Observation with Async Sequences](references/alarmkit patterns.md state observation with async sequences) for the complete store and refresh loop. An alarm that disappears from alarmUpdates is no longer scheduled with AlarmKit. Compare against app persisted IDs when you need to distinguish fired, cancelled, and rescheduled alarms. AlarmAttributes and AlarmPresentation AlarmAttributes conforms to ActivityAttributes and defines the static data for the alarm's Live Activity. It is generic over a Metadata type conforming to AlarmMetadata , which inherits Decodable , Encodable , Hashable , and Sendable . The metadata value itself is optional and defaults to nil . AlarmPresentation supplies the required alerting content and optional countdown/paused content. The system renders alerting UI; a widget extension can customize countdown and paused Live Activity views with the same attributes and presentation state. Keep metadata lightweight, use nil when it is unnecessary, and share its type with the widget extension. AlarmPresentationState AlarmPresentationState is the system managed ContentState of the alarm Live Activity. It contains the alarm ID and a Mode enum: .alert(Alert) alarm is firing, includes the scheduled time .countdown(Countdown) actively counting down, includes fire date and durations .paused(Paused) countdown paused, includes elapsed and total durations The widget extension reads AlarmPresentationState.mode to decide which UI to render in the Dynamic Island and Lock Screen for non alerting states. AlarmButton AlarmButton defines the text, color, and symbol for an alarm action. The representative scheduling example above shows a standard Snooze button. Secondary Button Behavior The secondary button on the alert UI has two behaviors: Behavior Effect .countdown Restarts a countdown using postAlert duration (snooze) .custom Triggers the secondaryIntent (e.g., open app) Live Activity Integration AlarmKit alarms appear as Live Activities on the Lock Screen, Dynamic Island, StandBy, and on a paired Apple Watch when the alarm fires. The system manages the alerting UI. For countdown and paused states, add a Widget Extension target whose ActivityConfiguration uses the same AlarmAttributes<Metadata type used when scheduling the alarm. A widget extension is expected if your alarm uses countdown presentation. Keep that lightweight metadata type available to both the app and widget extension. Without the extension, alarms may be dismissed unexpectedly or fail to alert, though the system can still show a fallback countdown UI in limited cases such as after a device restart before first unlock. Work Owner Authorization, scheduling/state, presentation, sound, system alarm actions AlarmKit Home Screen/Smart Stack widgets, families, timelines, reloads widgetkit Non alarm Live Activity lifecycle, tokens, remote content state activitykit APNs, notification categories/actions, custom notification UI push notifications AlarmKit's alert is system rendered on Lock Screen, Dynamic Island, StandBy, and paired Apple Watch; only countdown/paused states use the widget extension. For setup, name Apple documented NSAlarmKitUsageDescription and AlarmManager authorization. Do not require unsupported AlarmKit setup keys or com.apple.developer.alarmkit unless a current Apple source documents them. Load [Live Activity Widget Extension for Alarms](references/alarmkit patterns.md live activity widget extension for alarms) for the complete shared attributes widget implementation. Common Mistakes Mistake Correction Missing usage string or authorization gate Add NSAlarmKitUsageDescription ; handle denial before scheduling Timer used for recurrence Use an alarm with .weekly([...]) App owned state replaces alarmUpdates Observe the system sequence and reconcile by ID Intents added for standard Stop/Snooze Omit them unless cleanup/custom behavior requires one Large AlarmMetadata payload Keep lightweight metadata or reference app data by ID Deprecated stopButton initializer Use init(title:secondaryButton:secondaryButtonBehavior:) Review Checklist [ ] Setup and authorization gates pass without unsupported entitlement keys [ ] Alarm/timer choice, presentation, metadata, intents, snooze duration, and tint are valid [ ] Scheduled IDs are retained and reconciled through alarmUpdates ; operation errors are handled [ ] Countdown uses the shared Widget Extension attributes and presentation state [ ] System managed alert UI and adjacent skill ownership follow the routing table [ ] Sound, vibration, Stop/Snooze, and state changes pass on device testing References Patterns and code: [references/alarmkit patterns.md](references/alarmkit patterns.md) Apple docs: [AlarmKit](https://sosumi.ai/documentation/alarmkit) [AlarmManager](https://sosumi.ai/documentation/alarmkit/alarmmanager) [AlarmAttributes](https://sosumi.ai/documentation/alarmkit/alarmattributes) [Scheduling an alarm](https://sosumi.ai/documentation/alarmkit/scheduling an alarm with alarmkit)