name: apple-internal-docs
description: Consult Apple Internal Documentation for iOS 18+, macOS 15+, and visionOS 2+. Use when implementing modern frameworks (StoreKit, MapKit, WebKit, AlarmKit), adopting design systems (Liquid Glass), or using new Swift features (SwiftData inheritance, InlineArray).
allowed-tools: Read, Grep, Glob

Apple Internal Documentation

Overview

Use this skill to access and apply the latest Apple API documentation and implementation guides. These documents contain the source of truth for iOS 18+, Swift 6.2, and new design paradigms like Liquid Glass. Prioritize patterns found here over general web knowledge.

Workflow Decision Tree

Choose the path that matches the request:

1) Research an API or Feature

• Search: Use grep or glob in references/ for keywords (e.g., "PlaceDescriptor", "WebView", "AppTransaction").
• Identify: Select the specific markdown file covering the domain.
• Read: Analyze the "Overview" and "Usage" sections.

2) Implement a Feature

• Design System: If building UI, check *-Implementing-Liquid-Glass-Design.md for the specific framework (SwiftUI/UIKit/AppKit).
• Data Models: Use SwiftData-Class-Inheritance.md for complex models or MapKit-GeoToolbox-PlaceDescriptors.md for location data.
• Commerce: Refer to StoreKit-Updates.md for subscriptions and JWS signing.
• Web: Use the native WebView and WebPage from SwiftUI-WebKit-Integration.md.

3) Review & Refactor

• Check code against "Best Practices" in the relevant doc.
• Verify availability checks (e.g., #available(iOS 18.4, *) for new StoreKit features).
• Ensure accessibility compliance (e.g., Implementing-Assistive-Access-in-iOS.md).

Core Guidelines

• Liquid Glass: Use native APIs (glassEffect, UIGlassEffect) instead of custom blurs. See specific files for SwiftUI, UIKit, AppKit, or WidgetKit.
• SwiftData: Prefer class inheritance for hierarchical models over flat structures when appropriate.
• MapKit: Use PlaceDescriptor and GeoToolbox for standardized location handling.
• StoreKit: Implement SubscriptionOfferView for merchandising and check AppTransaction.shared for attribution.
• VisionOS: Handle specific widget textures (.glass vs .paper) and mounting styles (.recessed vs .elevated).

Implementation Checklist

• Doc Selection: Identified correct file in references/.
• Availability: Guarded code with correct #available checks (note: some features are iOS 18.4+).
• Patterns: Used specific snippets (e.g., GlassEffectContainer, WebView(page)).
• Configuration: Applied necessary Info.plist keys (e.g., for AlarmKit or Assistive Access).
• Performance: Verified against performance notes (e.g., InlineArray for hot paths).

Resources

The following documentation is available in the references/ directory:

Core Frameworks & Swift

• references/AppIntents-Updates.md
• references/Foundation-AttributedString-Updates.md
• references/FoundationModels-Using-on-device-LLM-in-your-app.md
• references/Swift-Concurrency-Updates.md
• references/Swift-InlineArray-Span.md
• references/SwiftData-Class-Inheritance.md

Liquid Glass Design System

• references/SwiftUI-Implementing-Liquid-Glass-Design.md
• references/UIKit-Implementing-Liquid-Glass-Design.md
• references/AppKit-Implementing-Liquid-Glass-Design.md
• references/WidgetKit-Implementing-Liquid-Glass-Design.md

App Services

• references/StoreKit-Updates.md
• references/MapKit-GeoToolbox-PlaceDescriptors.md
• references/SwiftUI-AlarmKit-Integration.md
• references/Implementing-Visual-Intelligence-in-iOS.md
• references/Implementing-Assistive-Access-in-iOS.md

SwiftUI Components

• references/SwiftUI-WebKit-Integration.md
• references/SwiftUI-Styled-Text-Editing.md
• references/SwiftUI-New-Toolbar-Features.md
• references/Swift-Charts-3D-Visualization.md
• references/Widgets-for-visionOS.md