Musickit

# MusicKit

Search the Apple Music catalog, manage playback with `ApplicationMusicPlayer`,
check subscriptions, and publish Now Playing metadata via `MPNowPlayingInfoCenter`
and `MPRemoteCommandCenter`. Targets Swift 6.3 / iOS 26+.

## Contents

- [Setup](#setup)
- [Authorization](#authorization)
- [Catalog Search](#catalog-search)
- [Subscription Checks](#subscription-checks)
- [Playback with ApplicationMusicPlayer](#playback-with-applicationmusicplayer)
- [Queue Management](#queue-management)
- [Now Playing Info](#now-playing-info)
- [Remote Command Center](#remote-command-center)
- [Common Mistakes](#common-mistakes)
- [Review Checklist](#review-checklist)
- [References](#references)

## Setup

### Project Configuration

1. Enable the **MusicKit** capability in Xcode (adds the `com.apple.developer.musickit` entitlement)
2. Add `NSAppleMusicUsageDescription` to Info.plist explaining why the app accesses Apple Music
3. For background playback, add the `audio` background mode to `UIBackgroundModes`

### Imports

```swift
import MusicKit       // Catalog, auth, playback
import MediaPlayer    // MPRemoteCommandCenter, MPNowPlayingInfoCenter
```

## Authorization

Request permission before accessing the user's music data or playing Apple Music content. Authorization is a one-time prompt per app install.

```swift
func requestMusicAccess() async -> MusicAuthorization.Status {
    let status = await MusicAuthorization.request()
    switch status {
    case .authorized:
        // Full access to MusicKit APIs
        break
    case .denied, .restricted:
        // Show guidance to enable in Settings
        break
    case .notDetermined:
        break
    @unknown default:
        break
    }
    return status
}

// Check current status without prompting
let current = MusicAuthorization.currentStatus
```

## Catalog Search

Use `MusicCatalogSearchRequest` to search the Apple Music catalog. The user must have an Apple Music subscription for full catalog access.

```swift
func searchCatalog(term: String) async throws -> MusicItemCollection<Song> {
    var request = MusicCatalogSearchRequest(term: term, types: [Song.self])
    request.limit = 25

    let response = try await request.response()
    return response.songs
}
```

### Displaying Results

```swift
for song in songs {
    print("\(song.title) by \(song.artistName)")
    if let artwork = song.artwork {
        let url = artwork.url(width: 300, height: 300)
        // Load artwork from url
    }
}
```

## Subscription Checks

Check whether the user has an active Apple Music subscription before offering playback features.

```swift
func checkSubscription() async throws -> Bool {
    let subscription = try await MusicSubscription.current
    return subscription.canPlayCatalogContent
}

// Observe subscription changes
func observeSubscription() async {
    for await subscription in MusicSubscription.subscriptionUpdates {
        if subscription.canPlayCatalogContent {
            // Enable full playback UI
        } else {
            // Show subscription offer
        }
    }
}
```

### Offering Apple Music

Present the Apple Music subscription offer sheet when the user is not subscribed.

```swift
import MusicKit
import SwiftUI

struct MusicOfferView: View {
    @State private var showOffer = false

    var body: some View {
        Button("Subscribe to Apple Music") {
            showOffer = true
        }
        .musicSubscriptionOffer(isPresented: $showOffer)
    }
}
```

## Playback with ApplicationMusicPlayer

`ApplicationMusicPlayer` plays Apple Music content independently from the Music app. It does not affect the system player's state.

```swift
let player = ApplicationMusic