/activitykit

name: activitykit
description: "Implement, review, or improve Live Activities and Dynamic Island experiences in iOS apps using ActivityKit. Use when building real-time updating widgets for the Lock Screen and Dynamic Island — delivery tracking, sports scores, ride-sharing status, workout timers, media playback, or any time-sensitive information that updates in real time. Also use when working with ActivityKit, ActivityAttributes, Activity lifecycle (request/update/end), Dynamic Island layouts (compact/minimal/expanded), push-to-update Live Activities, or Lock Screen live widgets."

ActivityKit

ActivityKit owns real-time, glanceable Live Activities displayed on the Lock Screen and Dynamic Island. Ordinary timeline widgets belong in `widgetkit`, and generic APNs setup belongs in `push-notifications`; ActivityKit owns the Live Activity lifecycle and payload contract. `aps.content-state` must decode into the exact `ActivityAttributes.ContentState` shape, including any coordinated custom date/range encoding. Modern `ActivityContent` lifecycle examples require iOS 16.2+ unless noted.

See [references/activitykit-patterns.md](references/activitykit-patterns.md) for complete code patterns including push payload formats, concurrent activities, state observation, and testing.

Contents

• [Workflow](#workflow)
• [ActivityAttributes Definition](#activityattributes-definition)
• [Activity Lifecycle](#activity-lifecycle)
• [Lock Screen Presentation](#lock-screen-presentation)
• [Dynamic Island](#dynamic-island)
• [Push-to-Update](#push-to-update)
• [Recent Additions](#recent-additions)
• [Common Mistakes](#common-mistakes)
• [Review Checklist](#review-checklist)
• [References](#references)

Workflow

1. Create a new Live Activity

1. Verify the host app capability and `NSSupportsLiveActivities = YES`. 2. Define `ActivityAttributes.ContentState`; encode and decode a representative fixture that matches the server payload contract. 3. Create `ActivityConfiguration` and preview Lock Screen and Dynamic Island states, including stale and terminal content. 4. Check `ActivityAuthorizationInfo.areActivitiesEnabled`, then request and observe the activity lifecycle. 5. Exercise local update and every terminal end path. 6. For remote updates, validate a complete reference payload before registering rotating update or push-to-start tokens with the server.

2. Review existing Live Activity code

Run through the Review Checklist at the end of this document.

ActivityAttributes Definition

Define both static data (immutable for the activity lifetime) and dynamic `ContentState` (changes with each update). Keep `ContentState` small because the entire struct is serialized on every update and push payload.

import ActivityKit

struct DeliveryAttributes: ActivityAttributes {
    // Static -- set once at activity creation, never changes
    var orderNumber: Int
    var restaurantName: String

    // Dynamic -- updated throughout the activity lifetime
    struct ContentState: Codable, Hashable {
        var driverName: String
        var estimatedDeliveryTime: ClosedRange<Date>
        var currentStep: DeliveryStep
    }
}

enum DeliveryStep: String, Codable, Hashable, CaseIterable {
    case confirmed, preparing, pickedUp, delivering, delivered

    var icon: String {
        switch self {
        case .confirmed: "checkmark.circle"
        case .preparing: "frying.pan"
        case .pickedUp: "bag.fill"
        case .delivering: "box.truck.fill"
        case .delivered: "house.fill"
        }
    }
}

Stale Date

Set `staleDate` on `ActivityContent` to tell the system when content becomes outdated. The system sets `context.isStale` to `true` after this date; show fallback UI (e.g., "Updating...") in your views.

let content = ActivityContent(
    state: state,
    staleDate: Date().addingTimeInterval(300), // stale after 5 minutes
    relevanceScore: 75
)

Activity Lifecycle

Starting

Use `Activity.request` to create and display a Live Activity. Pass `.token` as the `pushType` to enable remote updates via APNs. The `ActivityContent` request shown here requires iOS 16.2+.

let attributes = DeliveryAttributes(orderNumber: 42, restaurantName: "Pizza Place")
let state = DeliveryAttributes.ContentState(
    driverName: "Alex",
    estimatedDeliveryTime: Date()...Date().addingTimeInterval(1800),
    currentStep: .preparing
)
let content = ActivityContent(state: state, staleDate: nil, relevanceScore: 75)

do {
    let activity = try Activity.request(
        attributes: attributes,
        content: content,
        pushType: .token
    )
    print("Started activity: \(activity.id)")
} catch {
    print("Failed to start activity: \(error)")
}

Updating

Update the dynamic content state from the app. Use `AlertConfiguration` to trigger a visible banner and sound alongside the update.

let updatedState = DeliveryAttributes.ContentState(
    driverName: "Alex",
    estimatedDeliveryTime: Date()...Date().addingTimeInterval(600),
    currentStep: .delivering
)
let updatedContent = ActivityContent(
    state: updatedState,
    staleDate: Date().addingTimeInterval(300),
    relevanceScore: 90
)

// Silent update
await activity.update(updatedContent)

// Update with an alert
await activity.update(updatedContent, alertConfiguration: AlertConfiguration(
    title: "Order Update",
    body: "Your driver is nearby!",
    sound: .default
))

Ending

End the activity when the tracked event completes. Choose a dismissal policy to control how long the ended activity lingers on the Lock Screen.

let finalState = DeliveryAttributes.ContentState(
    driverName: "Alex",
    estimatedDeliveryTime: Date()...Date(),
    currentStep: .delivered
)
let finalContent = ActivityContent(state: finalState, staleDate: nil, relevanceScore: 0)

// System decides when to remove (up to 4 hours)
await activity.end(finalContent, dismissalPolicy: