AlarmKit

Framework for scheduling alarms and countdown timers with custom UI, Live Activities integration, and focus/silent mode override. Prevents the most common mistakes: using the wrong authorization property name, omitting the Info.plist key, and forgetting the widget extension for countdown presentations.

When This Skill Activates

Use this skill when the user:

• Asks to add, fix, or review alarm or timer functionality
• Mentions AlarmKit, AlarmManager, or AlarmPresentation
• Wants to schedule one-time, repeating, or countdown alarms
• Asks about snooze, stop, or repeat buttons on alarm alerts
• Wants alarms to appear on Dynamic Island or Lock Screen (Live Activities)
• Mentions overriding Focus or silent mode for alarms
• Asks about AlarmAttributes or AlarmMetadata

Decision Tree

Choose the right reference file based on what the user needs:

What do you need?
|
+-- Schedule an alarm (one-time, repeating, or timer)
|   --> scheduling.md
|       +-- One-time alarm: Alarm.Schedule.relative + .repeats: .never
|       +-- Repeating alarm: Alarm.Schedule.relative + .repeats: .weekly(weekdays)
|       +-- Countdown timer: CountdownDuration (no schedule)
|       +-- Authorization & Info.plist setup
|       +-- Managing alarms: pause, resume, cancel
|
+-- Customize alarm UI (alert, countdown, paused screens)
|   --> presentation.md
|       +-- AlarmPresentation.Alert: title, stop, snooze/repeat buttons
|       +-- AlarmPresentation.Countdown: title, pause button
|       +-- AlarmPresentation.Paused: title, resume button
|       +-- Custom buttons with AlarmButton
|       +-- Tint color and metadata via AlarmAttributes
|
+-- Show alarm on Dynamic Island / Lock Screen
    --> live-activities.md
        +-- Widget extension with ActivityConfiguration
        +-- AlarmAttributes conformance
        +-- Custom AlarmMetadata protocol

API Availability

Top Mistakes -- Quick Reference

Review Checklist

When reviewing AlarmKit code, verify:

• Info.plist -- NSAlarmKitUsageDescription is present with a meaningful description
• Authorization -- requestAuthorization() is called before scheduling; denial is handled gracefully
• Correct property -- uses .authorizationState, not .authorizationStatus
• Alarm ID persistence -- alarm UUIDs are stored (e.g., UserDefaults, SwiftData) for later management
• State observation -- alarmUpdates async sequence is used to keep UI in sync
• Widget extension -- exists if countdown or paused presentations are used
• Error handling -- schedule(), pause(), resume(), cancel() calls handle errors
• System limits -- code accounts for the system limit on number of active alarms
• Real device testing -- alarms are tested on physical devices, not just Simulator

Reference Files