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 skills add johnrogers/claude-swift-engineering --skill swiftui-patternsgit clone --depth 1 https://github.com/johnrogers/claude-swift-engineeringWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/johnrogers/claude-swift-engineering/swiftui-patterns)<a href="https://agentmods.dev/skills/johnrogers/claude-swift-engineering/swiftui-patterns"><img src="https://agentmods.dev/badge/skills/johnrogers/claude-swift-engineering/swiftui-patterns.svg" alt="Measured on agentmods" height="20"></a>What 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 5.1 | $0.00061 | $0.00952 |
| Opus 5 | $0.00030 | $0.00476 |
| Sonnet 5 | $0.00012 | $0.00190 |
| Haiku 4.5 | $0.00006 | $0.00095 |
Grade A, and why
swiftui-patterns 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 7d 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.
How it starts
The opening of the file, as written. The whole thing — 66 lines — stays where its author put it; the contents beside it link to each section on GitHub.
SwiftUI Patterns (iOS 17+)
SwiftUI 17+ removes ObservableObject boilerplate with @Observable, simplifies environment injection with @Environment, and introduces task-based async patterns. The core principle: use Apple's modern APIs instead of reactive libraries.
Overview
Quick Reference
| Need | Use (iOS 17+) | NOT |
|---|---|---|
| Observable model | @Observable |
ObservableObject |
| Published property | Regular property | @Published |
| Own state | @State |
@StateObject |
| Passed model (binding) | @Bindable |
@ObservedObject |
| Environment injection | environment(_:) |
environmentObject(_:) |
| Environment access | @Environment(Type.self) |
@EnvironmentObject |
| Async on appear | .task { } |
.onAppear { Task {} } |
| Value change | onChange(of:initial:_:) |
onChange(of:perform:) |
Core Workflow
- Use
@Observablefor model classes (no @Published needed) - Use
@Statefor view-owned models,@Bindablefor passed models - Use
.task { }for async work (auto-cancels on disappear) - Use
NavigationStackwithNavigationPathfor programmatic navigation - Apply
.accessibilityLabel()and.accessibilityHint()to interactive elements
Reference Loading Guide
ALWAYS load reference files if there is even a small chance the content may be required. It's better to have the context than to miss a pattern or make a mistake.
| Reference | Load When |
|---|---|
| Observable | Creating new @Observable model classes |
| State Management | Deciding between @State, @Bindable, @Environment |
| Environment | Injecting dependencies into view hierarchy |
| View Modifiers | Using onChange, task, or iOS 17+ modifiers |
| Migration Guide | Updating iOS 16 code to iOS 17+ |
| MVVM Observable | Setting up view model architecture |
| Navigation | Programmatic or deep-link navigation |
| Performance | Lists with 100+ items or excessive re-renders |
| UIKit Interop | Wrapping UIKit components (WKWebView, PHPicker) |
| Accessibility | VoiceOver, Dynamic Type, accessibility actions |
| Async Patterns | Loading states, refresh, background tasks |
| Composition | Reusable view modifiers or complex conditional UI |
What ships with it
12 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.
- references/accessibility.md 2.3 KB
- references/async-patterns.md 2.1 KB
- references/composition.md 2.4 KB
- references/environment.md 825 B
- references/migration-guide.md 1.3 KB
- references/mvvm-observable.md 1.7 KB
- references/navigation.md 1.6 KB
- references/observable.md 1.1 KB
- references/performance.md 2.7 KB
- references/state-management.md 2.4 KB
- references/uikit-interop.md 3.5 KB
- references/view-modifiers.md 1.5 KB
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.
- 7d ago First seen · 66 lines · 61 tokens per session scan A bfc3e2bcd4ce
swiftui-patterns is a skill published in the GitHub repository johnrogers/claude-swift-engineering (228 stars, last pushed 7mo ago), licensed MIT. It adds 61 tokens to every session and 952 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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