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 johnkozaris/jko-claude-plugins --skill swiftui-expertgit clone --depth 1 https://github.com/johnkozaris/jko-claude-pluginsWrote 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/johnkozaris/jko-claude-plugins/swiftui-expert)<a href="https://agentmods.dev/skills/johnkozaris/jko-claude-plugins/swiftui-expert"><img src="https://agentmods.dev/badge/skills/johnkozaris/jko-claude-plugins/swiftui-expert/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/johnkozaris/jko-claude-plugins/swiftui-expert"><img src="https://agentmods.dev/badge/skills/johnkozaris/jko-claude-plugins/swiftui-expert.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00133 | $0.00982 |
| Opus 5 | $0.00067 | $0.00491 |
| Sonnet 5 | $0.00027 | $0.00196 |
| Haiku 4.5 | $0.00013 | $0.00098 |
Grade A, and why
swiftui-expert 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 9d 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 — 87 lines — stays where its author put it; the contents beside it link to each section on GitHub.
SwiftUI Expert
Inspect the project before applying a default. Read its deployment targets, Swift language mode, existing state patterns, platform targets, dependencies, and nearby code. Look up current Apple documentation before making a load-bearing claim about API behavior or availability.
If a missing target, isolation setting, ownership fact, deep-link/restoration need, sync topology, offline behavior, or minimum-OS decision would materially change the answer, ask one focused question or present conditional recommendations.
Opinions worth carrying
- Use SwiftUI's data flow directly by default. Let views compose sources of
truth with
@State,@Environment,@Bindable, and query wrappers. Add a ViewModel when it owns real orchestration: a state machine, retries, pagination, optimistic updates, lifecycle independent of one view, or a valuable test seam. Do not introduce one merely to move properties out of a view. - Own shared observable state at a clear ancestor. App-wide
@Observableinstances normally originate inAppand enter the environment. Keep ownership distinct from observation and binding extraction. - Model navigation as state when the product needs restoration, deep links, or independent tab histories. Prefer typed destinations and keep one navigation history per independent surface. Do not force a router into a small linear flow that gains nothing from it.
- Treat view identity and lifecycle as correctness concerns. Work tied to a view belongs in lifecycle-aware tasks; structural changes, unstable IDs, and hidden side effects can recreate state or repeat work unexpectedly.
- Use modern concurrency deliberately. Match recommendations to the
project's Swift mode and isolation settings. App targets often benefit from
main-actor defaults; reusable non-UI packages often should remain
nonisolated. Treat
@unchecked Sendableas a synchronization claim that must be visible in the code. - Respect the platform. A Mac app needs menus, keyboard behavior, windows, and AppKit bridges where SwiftUI is weak. An iOS app needs real accessibility, lifecycle, permission, privacy, and background-behavior review. Do not infer one platform's conventions from another.
- Do not modernize for sport. Preserve coherent working patterns on older deployment targets unless the current change benefits from migration.
What ships with it
8 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-and-performance.md 1.2 KB
- references/concurrency.md 1.1 KB
- references/lifecycle-and-navigation.md 1.4 KB
- references/persistence.md 1.8 KB
- references/platform.md 866 B
- references/state-and-architecture.md 1.7 KB
- references/testing-and-api.md 1.1 KB
- references/visual-system.md 1.2 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.
- 9d ago First seen · 87 lines · 133 tokens per session scan A fada4f44628a
swiftui-expert is a skill published in the GitHub repository johnkozaris/jko-claude-plugins (11 stars, last pushed 12d ago), licensed MIT. It adds 133 tokens to every session and 982 once invoked, about $0.0007 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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