Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add skills/chama-x/groundrules/macosnpx skills add chama-x/GroundRules --skill macosgit clone --depth 1 https://github.com/chama-x/GroundRulesWhat it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00055 | $0.08702 |
| Opus 5 | $0.00028 | $0.04351 |
| Sonnet 5 | $0.00011 | $0.01740 |
| Haiku 4.5 | $0.00006 | $0.00870 |
Grade A, and why
macos-design-guidelines scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
This is a copy
100% identical to macos-design-guidelines — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 1,123 lines — stays where its author put it; the contents beside it link to each section on GitHub.
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.
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.
What ships with it
3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 2d ago First seen · 1,123 lines · 55 tokens per session scan A 9fa44a38eee0
macos-design-guidelines is a skill published in the GitHub repository chama-x/GroundRules (5 stars, last pushed 19d ago), licensed MIT. It adds 55 tokens to every session and 8,702 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to macos-design-guidelines, differing in 0 lines, and is treated as a copy.
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