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/jezweb/claude-skills/react-nativenpx skills add jezweb/claude-skills --skill react-nativegit clone --depth 1 https://github.com/jezweb/claude-skillsWrote 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/jezweb/claude-skills/react-native)<a href="https://agentmods.dev/skills/jezweb/claude-skills/react-native"><img src="https://agentmods.dev/badge/skills/jezweb/claude-skills/react-native.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 | $0.00091 | $0.02346 |
| Opus 5 | $0.00046 | $0.01173 |
| Sonnet 5 | $0.00018 | $0.00469 |
| Haiku 4.5 | $0.00009 | $0.00235 |
Grade A, and why
react-native 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 3d 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 — 183 lines — stays where its author put it; the contents beside it link to each section on GitHub.
React Native Patterns
Performance and architecture patterns for React Native + Expo apps. Rules ranked by impact — fix CRITICAL before touching MEDIUM.
This is a starting point. The skill will grow as you build more mobile apps.
When to Apply
- Building new React Native or Expo apps
- Optimising list and scroll performance
- Implementing animations
- Reviewing mobile code for performance issues
- Setting up a new Expo project
1. List Performance (CRITICAL)
Lists are the #1 performance issue in React Native. A janky scroll kills the entire app experience.
| Pattern | Problem | Fix |
|---|---|---|
| ScrollView for data | <ScrollView> renders all items at once |
Use <FlatList> or <FlashList> — virtualised, only renders visible items |
| Missing keyExtractor | FlatList without keyExtractor → unnecessary re-renders |
keyExtractor={(item) => item.id} — stable unique key per item |
| Complex renderItem | Expensive component in renderItem re-renders on every scroll | Wrap in React.memo, extract to separate component |
| Inline functions in renderItem | renderItem={({ item }) => <Row onPress={() => nav(item.id)} />} |
Extract handler: const handlePress = useCallback(...) |
| No getItemLayout | FlatList measures every item on scroll (expensive) | Provide getItemLayout for fixed-height items: (data, index) => ({ length: 80, offset: 80 * index, index }) |
| FlashList | FlatList is good, FlashList is better for large lists | @shopify/flash-list — drop-in replacement, recycling architecture |
| Large images in lists | Full-res images decoded on main thread | Use expo-image with placeholder + transition, specify dimensions |
FlatList Checklist
Every FlatList should have:
<FlatList
data={items}
keyExtractor={(item) => item.id}
renderItem={renderItem} // Memoised component
getItemLayout={getItemLayout} // If items are fixed height
initialNumToRender={10} // Don't render 100 items on mount
maxToRenderPerBatch={10} // Batch size for off-screen rendering
windowSize={5} // How many screens to keep in memory
removeClippedSubviews={true} // Unmount off-screen items (Android)
/>
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.
- 3d ago First seen · 183 lines · 91 tokens per session scan A c32065f601f2
react-native is a skill published in the GitHub repository jezweb/claude-skills (995 stars, last pushed 2mo ago), licensed MIT. It adds 91 tokens to every session and 2,346 once invoked, about $0.0005 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 2026-09-03.
Other skills, from other repositories
expo-react-native-expert
Use when building mobile applications with Expo and React Native that require native module integration, navigation setup, performant animations, push notifications, OTA updates, or App Store/Play Store deployment.
mobile-developer
Use when building iOS and Android apps, native or cross-platform (React Native, Flutter), with a focus on native performance, platform-specific UX, and offline-first architecture.
react-native-expert
Builds, optimizes, and debugs cross-platform mobile applications with React Native and Expo. Implements navigation hierarchies (tabs, stacks, drawers), configures native modules, optimizes FlatList rendering with memo and useCallback, and handles platform-specific code for iOS and Android. Use when building a React…
frontend-code-review
Trigger when the user requests a review of frontend files (e.g., .tsx, .ts, .js). Support both pending-change reviews and focused file reviews while applying the checklist rules.
frontend
Builds, styles, and polishes web UI and UX. Use for any frontend, page, component, styling, layout, animation, or visual-quality task, or when asked to make an interface look or feel a certain way.
animation-patterns
Framer Motion patterns, page transitions, skeleton loading, scroll-linked animations, and gesture-based interactions for React.