Use when designing or building native macOS applications with SwiftUI or AppKit. Triggers on menu bar structure, keyboard shortcuts, multi-window behavior, Liquid Glass design system, macOS Tahoe/Sequoia, sidebar navigation, toolbar design, app icons, SF Symbols, or making an app feel like a "good M

macOS App Design & Development Guide for designing and implementing native feeling, "good Mac citizen" apps: fast, elegant, accessible, and deeply integrated with macOS workflows. Two Rules That Beat Everything Else 1. Prefer system components and conventions over bespoke UI—fastest path to "feels right on Mac" 2. If you customize bars, backgrounds, borders, or control chrome : stop and justify it Quick Reference: Mac Citizen Checklist Area Requirement Menu Bar Standard layout (App/File/Edit/View/Window/Help), ⌘, for Settings Keyboard Every primary command reachable via keyboard, standard shortcuts work Windows Resize fluidly, support multiple windows, respect fullscreen/minimize Sidebars Top level navigation, scannable items, content extends behind Toolbars Group by function/frequency, demote secondary to "more" menu Text Use system text components, standard editing behaviors Accessibility VoiceOver labels, full keyboard navigation, Reduced Motion support Liquid Glass Quick Rules Do: Use for navigation/controls layer (toolbars, sidebars, bars) Let system components provide built in behaviors Don't: Apply to content layer (tables, lists, document content) Stack "glass on glass" App Archetypes Identify your app type first: Document based : Files as primary units (open/save/duplicate) Library + editor : Sidebar lists items, detail in main area Utility : Single window, optional menu bar Menu bar app : Lives in menu bar, minimal UI Pro tool : Dense, power user workflows Deliverables Before Building 1. App archetype identified 2. Information architecture (sidebar structure, navigation, window model) 3. Command map (menus + keyboard shortcuts for every major feature) 4. State + data model (persistence, undo/redo, concurrency) 5. Accessibility plan (VoiceOver, keyboard, contrast, reduce motion) Full Reference For complete design system details, Icon Composer workflow, SF Symbols guidance, evaluation rubrics, and Definition of Done checklist: See: [references/macos design guide.md](references/macos design guide.md) Common Mistakes Mistake Fix Missing menu bar commands Every feature in menus with keyboard shortcuts Settings outside App menu Always ⌘, opening from App menu Custom text components Use system text for Mac editing ecosystem Toolbar overload Demote secondary actions, group by function Glass on content Reserve Liquid Glass for navigation layer only Breaking standard shortcuts Never override ⌘C, ⌘V, ⌘Z, etc. Single window only Support multiple windows when it benefits workflows

macos-app-design