AlarmKit Bridge Component

[niklasbabel]

Overview

This proposal outlines the addition of an AlarmKit bridge component to the joemasilotti/bridge-components repository. AlarmKit is Apple's new framework (introduced in iOS 26) that allows apps to create and manage system-level alarms with Lock Screen integration, Dynamic Island support, and Live Activities.

Component Description

The AlarmKit bridge component would enable Hotwire Native apps to:

• Create and schedule system alarms from web views
• Manage alarm lifecycle (start, stop, pause, resume)
• Configure alarm appearance with custom Live Activities
• Handle alarm actions through App Intents
• Check and request alarm permissions

Proposed Features

Core Functionality

1. Alarm Creation: Schedule one-time or repeating alarms
2. Countdown Support: Create countdown timers with Live Activity updates
3. Permission Management: Check and request AlarmKit authorization
4. Alarm Management: Update, cancel, and query existing alarms
5. Custom Actions: Define App Intent actions for alarm buttons

Bridge Interface

<!-- Schedule an alarm -->
<div data-controller="bridge--alarm"
     data-bridge-alarm-identifier="morning-alarm"
     data-bridge-alarm-hour="7"
     data-bridge-alarm-minute="30"
     data-bridge-alarm-label="Morning Workout"
     data-bridge-alarm-sound="default"
     data-bridge-alarm-repeats="weekdays">
  <button data-action="click->bridge--alarm#schedule">Set Alarm</button>
</div>

<!-- Create a countdown timer -->
<div data-controller="bridge--alarm"
     data-bridge-alarm-identifier="cooking-timer"
     data-bridge-alarm-countdown="1800"
     data-bridge-alarm-label="Pizza Timer">
  <button data-action="click->bridge--alarm#startCountdown">Start Timer</button>
</div>

Implementation Structure

iOS Component (AlarmComponent.swift)

import HotwireNative
import AlarmKit
import ActivityKit

final class AlarmComponent: BridgeComponent {
    override class var name: String { "alarm" }
    
    override func onReceive(message: Message) {
        guard let data = message.data else { return }
        
        switch message.event {
        case "schedule":
            scheduleAlarm(with: data)
        case "startCountdown":
            startCountdown(with: data)
        case "cancel":
            cancelAlarm(with: data)
        case "checkPermission":
            checkAlarmPermission()
        default:
            break
        }
    }
    
    private func scheduleAlarm(with data: MessageData) {
        // Implementation for scheduling alarms
    }
    
    private func startCountdown(with data: MessageData) {
        // Implementation for countdown timers
    }
}

JavaScript Controller (alarm_controller.js)

import { BridgeComponent } from "@hotwired/hotwire-native-bridge"

export default class extends BridgeComponent {
  static component = "alarm"
  
  schedule(event) {
    event.preventDefault()
    
    const data = {
      identifier: this.identifierValue,
      hour: parseInt(this.hourValue),
      minute: parseInt(this.minuteValue),
      label: this.labelValue,
      sound: this.soundValue,
      repeats: this.repeatsValue
    }
    
    this.send("schedule", data)
  }
  
  startCountdown(event) {
    event.preventDefault()
    
    const data = {
      identifier: this.identifierValue,
      duration: parseInt(this.countdownValue),
      label: this.labelValue
    }
    
    this.send("startCountdown", data)
  }
  
  // Additional methods...
}

Use Cases

1. Fitness Apps: Schedule workout reminders with custom actions
2. Recipe Apps: Set cooking timers with Live Activity updates
3. Travel Apps: Create wake-up alarms for different time zones
4. Study Apps: Set study session reminders and break timers
5. Medication Apps: Schedule medication reminders

Benefits

• Native Experience: Alarms appear on Lock Screen and Dynamic Island
• System Integration: Works even when app is closed
• Live Activities: Real-time countdown updates
• Custom Actions: App-specific buttons in alarm interface
• Cross-Platform: Web-based configuration with native execution

Considerations

iOS Version Requirement

• Requires iOS 26+ for AlarmKit support
• Need graceful fallback for older iOS versions

Permissions

• Must request alarm permissions from user
• Handle denied permission scenarios

Android Parity

• Consider using Android's AlarmManager API for similar functionality: https://developer.android.com/reference/android/app/AlarmManager

References

• [AlarmKit Documentation](https://developer.apple.com/documentation/AlarmKit)
• [WWDC25: Wake up to the AlarmKit API](https://developer.apple.com/videos/play/wwdc2025/230/)
• [ActivityKit Integration](https://developer.apple.com/documentation/activitykit)