iOS Development

Start here. This skill coordinates the Apple skills collection — it tells you which skill to use and when, so you get opinionated guidance and full API references together.

Operating Rules

• Do not bridge UIKit/AppKit when SwiftUI has a native solution — bridging adds state-sync bugs, breaks SwiftUI composition (animations, environment), and complicates lifecycle management
• Do not enforce specific architectures (MVVM, VIPER, MV, TCA, etc.) — encourage separating business logic from views without mandating how
• Liquid Glass is the default iOS 26+ design system — use system glass behaviors naturally, but add custom GlassEffect modifiers only when they serve the UI, not for decoration
• Present performance optimizations as suggestions backed by reasoning, not blanket requirements
• When you need exact API details, grep the framework reference skills — they contain full Apple documentation

Task Workflows

Review existing code

1. Read the code and identify which topics apply
2. Run the Correctness Checklist below — violations are bugs
3. Use the Topic Router to load the relevant guide for each topic
4. For API correctness, grep the matching framework reference skill

Improve existing code

1. Run the correctness checklist first
2. For performance issues: use guide-swiftui-performance-audit
3. For view structure / long bodies: use guide-swiftui-view-refactor
4. For navigation, state, or pattern questions: use guide-swiftui-ui-patterns
5. For visual quality: use ios-ui-craft
6. For API details: grep the matching framework reference skill

Build a new feature

1. Design data flow first — identify owned vs. injected state
2. For UI patterns and app wiring: use guide-swiftui-ui-patterns
3. For API details: grep the matching framework reference skill
4. Structure views for optimal diffing — extract subviews early
5. Run the correctness checklist before finishing
6. For visual polish: use ios-ui-craft

Topic Router

The Guide column has opinionated, short pattern guides. The API Reference column has full Apple documentation as grepable Markdown — use apple-docs-index to find which framework has what.

Topic	Guide	API Reference
State management	guide-swiftui-ui-patterns	swiftui (state.md, binding.md, observation.md, environment.md)
View composition	guide-swiftui-view-refactor	swiftui (view-protocol.md)
Performance	guide-swiftui-performance-audit	—
Navigation	guide-swiftui-ui-patterns	swiftui (navigationstack.md, navigationsplitview.md, navigationlink.md)
Sheets & modals	guide-swiftui-ui-patterns	swiftui (sheet.md, inspector.md, alert.md, confirmationdialog.md)
Lists & ForEach	guide-swiftui-ui-patterns	swiftui (list.md)
ScrollView	guide-swiftui-ui-patterns	swiftui (scrollview.md)
Forms & input	—	swiftui (form.md, textfield.md, picker.md, toggle.md, slider.md)
Charts	guide-swiftui-charts	swiftui (chart.md, charts-overview.md)
Animations	guide-swiftui-animations	swiftui (swiftui-overview.md)
Layout	guide-swiftui-ui-patterns	swiftui (geometryreader.md, grid.md, hstack.md, vstack.md, zstack.md, spacer.md)
TabView	guide-swiftui-ui-patterns	swiftui (tabview.md)
Liquid Glass	ios-design-consultant	ios-liquid-glass
Visual design	ios-ui-craft	hig
Accessibility	guide-swiftui-ui-patterns	hig
macOS apps	guide-macos-spm-packaging	swiftui, uikit
Data persistence	guide-swiftdata	swiftdata
Testing	guide-swift-testing	swift-testing, xcuitest
Concurrency	guide-swift-concurrency	swift-concurrency
In-app purchases	—	storekit
Maps	—	mapkit
Health data	—	healthkit
Notifications	—	usernotifications
App Intents / Siri	—	appintents
Widgets	—	widgetkit
App Store metadata	apple-aso	—
Finding docs	apple-docs-index	—

Correctness Checklist

These are hard rules — violations are always bugs:

• @State properties are private
• @Binding only where a child needs to mutate parent state
• Values passed in are never declared as @State — they silently ignore updates
• Use @State with @Observable classes — not @StateObject or ObservableObject
• Use @Bindable for injected observables that need bindings
• ForEach uses stable identity — never .indices on dynamic content
• Each ForEach element produces a constant number of views
• .animation(_:value:) always includes the value: parameter
• @FocusState properties are private
• @Observable classes are @MainActor — Swift 6 strict concurrency requires it
• Property wrappers (@AppStorage, @SceneStorage, @Query) inside @Observable classes are marked @ObservationIgnored — they conflict with the macro and cause compiler errors
• No business logic in body — use .task, .onChange, or methods
• No AnyView unless truly unavoidable — fix with better composition

Related Skills

Design trio:

• /ios-ui-craft — Build visually striking interfaces (produces code)
• /ios-design-consultant — Design advice and rationale (no code)
• /ios-liquid-glass — Liquid Glass API reference

Workflow guides:

• /guide-swiftui-ui-patterns — Navigation, state, sheets, component patterns
• /guide-swiftui-animations — Implicit/explicit animation, transitions, keyframes
• /guide-swiftui-charts — Marks, axes, selection, styling, accessibility
• /guide-swiftui-view-refactor — View structure, extraction, MV patterns
• /guide-swiftui-performance-audit — Diagnose and fix performance issues
• /guide-swift-testing — Swift Testing patterns, async tests, common agent mistakes
• /guide-swift-concurrency — Concurrency patterns, actors, diagnostics, bug patterns
• /guide-swiftdata — SwiftData patterns, predicates, CloudKit constraints
• /guide-macos-spm-packaging — Build macOS apps with SwiftPM

Utilities:

• /apple-docs-index — Find the right Apple documentation
• /simulator-utils — Simulator screenshots and device management
• /apple-aso — App Store Optimization