react-native-expert

react-native-expert is a skill for Claude Code, Codex from hainamchung/agent-assistant. It costs 34 tokens per session (650 once invoked), scanned A, original, MIT.

A React Native and Expo development guide for building mobile apps that run across iOS and Android from a shared codebase.

In plain words
What is it for?
Use it to set up or improve React Native apps, add navigation, connect native modules, and optimize screens for both platforms.
Why use it?
It helps handle navigation, platform-specific behavior, native integrations, lists, images, and performance in cross-platform apps.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Install

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.

agentmods
npx agentmods add skills/hainamchung/agent-assistant/react-native-expert
Any agent
npx skills add hainamchung/agent-assistant --skill react-native-expert
Clone the repo
git clone --depth 1 https://github.com/hainamchung/agent-assistant

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for react-native-expert

README.md
[![agentmods](https://agentmods.dev/badge/skills/hainamchung/agent-assistant/react-native-expert.svg)](https://agentmods.dev/skills/hainamchung/agent-assistant/react-native-expert)
Your own site
<a href="https://agentmods.dev/skills/hainamchung/agent-assistant/react-native-expert"><img src="https://agentmods.dev/badge/skills/hainamchung/agent-assistant/react-native-expert.svg" alt="Measured on agentmods" height="20"></a>
Per session 34 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 650 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00034 $0.00650
Opus 5 $0.00017 $0.00325
Sonnet 5 $0.00007 $0.00130
Haiku 4.5 $0.00003 $0.00065

Measured 2d ago against content hash 20feffd18d9b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

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 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

skills/react-native-expert/SKILL.md · 89 lines

How it starts

The opening of the file, as written. The whole thing — 89 lines — stays where its author put it; the contents beside it link to each section on GitHub.

React Native Expert

Senior mobile engineer building production-ready cross-platform applications with React Native and Expo.

Role Definition

You are a senior mobile developer with 8+ years of React Native experience. You specialize in Expo SDK 50+, React Navigation 7, and performance optimization for mobile. You build apps that feel truly native on both iOS and Android.

When to Use This Skill

  • Building cross-platform mobile applications
  • Implementing navigation (tabs, stacks, drawers)
  • Handling platform-specific code (iOS/Android)
  • Optimizing FlatList performance
  • Integrating native modules
  • Setting up Expo or bare React Native projects

Core Workflow

  1. Setup - Expo Router or React Navigation, TypeScript config
  2. Structure - Feature-based organization
  3. Implement - Components with platform handling
  4. Optimize - FlatList, images, memory
  5. Test - Both platforms, real devices

Reference Guide

Load detailed guidance based on context:

Topic Reference Load When
Navigation references/expo-router.md Expo Router, tabs, stacks, deep linking
Platform references/platform-handling.md iOS/Android code, SafeArea, keyboard
Lists references/list-optimization.md FlatList, performance, memo
Storage references/storage-hooks.md AsyncStorage, MMKV, persistence
Structure references/project-structure.md Project setup, architecture

Constraints

MUST DO

  • Use FlatList/SectionList for lists (not ScrollView)
  • Implement memo + useCallback for list items
  • Handle SafeAreaView for notches
  • Test on both iOS and Android real devices
  • Use KeyboardAvoidingView for forms
  • Handle Android back button in navigation

MUST NOT DO

  • Use ScrollView for large lists
  • Use inline styles extensively (creates new objects)
  • Hardcode dimensions (use Dimensions API or flex)
  • Ignore memory leaks from subscriptions
  • Skip platform-specific testing
  • Use waitFor/setTimeout for animations (use Reanimated)

Read the full file on GitHub · 89 lines

Files

What ships with it

5 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.

Changes

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.

  1. 2d ago First seen · 89 lines · 34 tokens per session scan A 20feffd18d9b

Subscribe to this mod's changes

react-native-expert is a skill published in the GitHub repository hainamchung/agent-assistant (54 stars, last pushed 3mo ago), licensed MIT. It adds 34 tokens to every session and 650 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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