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/hoangatg/ai-agent-toolkit/react-native-expertnpx skills add hoangatg/ai-agent-toolkit --skill react-native-expertgit clone --depth 1 https://github.com/hoangatg/ai-agent-toolkitWrote 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/hoangatg/ai-agent-toolkit/react-native-expert)<a href="https://agentmods.dev/skills/hoangatg/ai-agent-toolkit/react-native-expert"><img src="https://agentmods.dev/badge/skills/hoangatg/ai-agent-toolkit/react-native-expert.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 | $0.00035 | $0.00885 |
| Opus 5 | $0.00017 | $0.00443 |
| Sonnet 5 | $0.00007 | $0.00177 |
| Haiku 4.5 | $0.00003 | $0.00089 |
Grade A, and why
react-native-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 today.
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 — 135 lines — stays where its author put it; the contents beside it link to each section on GitHub.
React Native Expert
One codebase, two platforms — done right.
1. Architecture Decisions
Expo vs Bare Workflow
| Factor | Expo | Bare |
|---|---|---|
| Setup | Minutes | Hours |
| Native modules | Limited (Expo SDK) | Full access |
| OTA updates | Built-in (EAS Update) | Manual (CodePush) |
| Build | EAS Build (cloud) | Local Xcode/Android Studio |
| Best for | 90% of apps | Custom native code needs |
Rule: Start with Expo. Eject only when you must.
2. Navigation
React Navigation Patterns
| Pattern | Use Case |
|---|---|
| Stack | Linear flows (auth, onboarding) |
| Tab | Main app sections |
| Drawer | Settings, secondary nav |
| Modal | Overlays, forms |
| Deep linking | URL-based navigation |
Principles
| Principle | Application |
|---|---|
| Type-safe routes | Use TypeScript route params |
| Lazy loading | Load screens on demand |
| State persistence | Save nav state for app restart |
| Deep links | Configure linking for all screens |
3. State Management
| Solution | Best For |
|---|---|
| React Context | Simple, app-wide state |
| Zustand | Lightweight, performant |
| Redux Toolkit | Complex state, middleware |
| React Query/TanStack | Server state, caching |
| MMKV | Persistent local storage |
4. Performance
Critical Optimizations
| Technique | Impact |
|---|---|
| FlatList over ScrollView | Virtual rendering for lists |
| React.memo | Prevent unnecessary re-renders |
| useCallback/useMemo | Memoize callbacks and values |
| Hermes engine | Faster startup, less memory |
| Image optimization | Use expo-image or FastImage |
| Native driver | useNativeDriver: true for animations |
Performance Budget
| Metric | Target |
|---|---|
| App startup | < 2 seconds |
| Frame rate | 60 fps |
| Bundle size | < 20MB (initial) |
| RAM usage | < 200MB |
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.
- today First seen · 135 lines · 35 tokens per session scan A f83618d7e705
react-native-expert is a skill published in the GitHub repository hoangatg/ai-agent-toolkit (1 stars, last pushed 5mo ago), licensed MIT. It adds 35 tokens to every session and 885 once invoked, about $0.0002 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.
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