GroundRules: Skill for Claude Code

macOS Human Interface Guidelines

Mac apps serve power users who expect deep keyboard control, persistent menu bars, resizable multi-window layouts, and tight system integration. These guidelines codify Apple's HIG into actionable rules with SwiftUI and AppKit examples.

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1. Menu Bar (CRITICAL)

Every Mac app must have a menu bar. It is the primary discovery mechanism for commands. Users who cannot find a feature will look in the menu bar before anywhere else.

Rule 1.1 — Provide Standard Menus

Every app must include at minimum: App, File, Edit, View, Window, Help. Omit File only if the app is not document-based. Add app-specific menus between Edit and View or between View and Window.

// SwiftUI — Standard menu structure
@main
struct MyApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
        .commands {
            // Adds to existing standard menus
            CommandGroup(after: .newItem) {
                Button("New from Template...") { newFromTemplate() }
                    .keyboardShortcut("T", modifiers: [.command, .shift])
            }
            CommandMenu("Canvas") {
                Button("Zoom to Fit") { zoomToFit() }
                    .keyboardShortcut("0", modifiers: .command)
                Divider()
                Button("Add Artboard") { addArtboard() }
                    .keyboardShortcut("A", modifiers: [.command, .shift])
            }
        }
    }
}

// AppKit — Building menus programmatically
let editMenu = NSMenu(title: "Edit")
let undoItem = NSMenuItem(title: "Undo", action: #selector(UndoManager.undo), keyEquivalent: "z")
let redoItem = NSMenuItem(title: "Redo", action: #selector(UndoManager.redo), keyEquivalent: "Z")
editMenu.addItem(undoItem)
editMenu.addItem(redoItem)
editMenu.addItem(.separator())

Rule 1.2 — Keyboard Shortcuts for All Menu Items

Every menu item that performs an action must have a keyboard shortcut. Use standard shortcuts for standard actions (Cmd+C, Cmd+V, Cmd+Z, etc.). Custom shortcuts should use Cmd plus a letter. Reserve Cmd+Shift, Cmd+Option, and Cmd+Ctrl combos for secondary actions.