Mmcp.market

react-native-expert skill

by Jeffallan·Jeffallan/claude-skills·12k stars·MIT

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 Native or Expo mobile app, setting up navigation, integrating native modules, improving scroll performance, handling SafeArea or keyboard input, or configuring Expo SDK projects.

A100/100content scan

Is the react-native-expert skill safe?

Clean: nothing in its files matched our rules. We read 6 files in the folder on 2026-09-28.

No findings.

Install the react-native-expert skill

A skill is a folder. Copy it into your agent's skills folder and the agent loads it when the task matches its description.

git clone --depth 1 https://github.com/Jeffallan/claude-skills.git /tmp/claude-skills
mkdir -p ~/.claude/skills
cp -r /tmp/claude-skills/skills/react-native-expert ~/.claude/skills/react-native-expert
available in every project

In the Claude apps, zip the folder and upload it from the Skills settings. The folder on GitHub

The instructions your agent would load

SKILL.md as published, without the frontmatter. Read it on GitHub

React Native Expert

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

Core Workflow

  1. Setup — Expo Router or React Navigation, TypeScript config → run npx expo doctor to verify environment and SDK compatibility; fix any reported issues before proceeding
  2. Structure — Feature-based organization
  3. Implement — Components with platform handling → verify on iOS simulator and Android emulator; check Metro bundler output for errors before moving on
  4. Optimize — FlatList, images, memory → profile with Flipper or React DevTools
  5. Test — Both platforms, real devices

Error Recovery

  • Metro bundler errors → clear cache with npx expo start --clear, then restart
  • iOS build fails → check Xcode logs → resolve native dependency or provisioning issue → rebuild with npx expo run:ios
  • Android build fails → check adb logcat or Gradle output → resolve SDK/NDK version mismatch → rebuild with npx expo run:android
  • Native module not found → run npx expo install to ensure compatible version, then rebuild native layers

Reference Guide

Load detailed guidance based on context:

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)

Code Examples

Optimized FlatList with memo + useCallback

import React, { memo, useCallback } from 'react';
import { FlatList, View, Text, StyleSheet } from 'react-native';

type Item = { id: string; title: string };

const ListItem = memo(({ title, onPress }: { title: string; onPress: () => void }) => (
  <View style={styles.item}>
    <Text onPress={onPress}>{title}</Text>
  </View>
));

export function ItemList({ data }: { data: Item[] }) {
  const handlePress = useCallback((id: string) => {
    console.log('pressed', id);
  }, []);

  const renderItem = useCallback(
    ({ item }: { item: Item }) => (
      <ListItem title={item.title} onPress={() => handlePress(item.id)} />
    ),
    [handlePress]
  );

  return (
    <FlatList
      data={data}
      keyExtractor={(item) => item.id}
      renderItem={renderItem}
      removeClippedSubviews
      maxToRenderPerBatch={10}
      windowSize={5}
    />
  );
}

const styles = StyleSheet.create({
  item: { padding: 16, borderBottomWidth: StyleSheet.hairlineWidth },
});

KeyboardAvoidingView Form

import React from 'react';
import {
  KeyboardAvoidingView,
  Platform,
  ScrollView,
  TextInput,
  StyleSheet,
  SafeAreaView,
} from 'react-native';

export function LoginForm() {
  return (
    <SafeAreaView style={styles.safe}>
      <KeyboardAvoidingView
        style={styles.flex}
        behavior={Platform.OS === 'ios' ? 'padding' : 'height'}
      >
        <ScrollView contentContainerStyle={styles.content} keyboardShouldPersistTaps="handled">
          <TextInput style={styles.input} placeholder="Email" autoCapitalize="none" />
          <TextInput style={styles.input} placeholder="Password" secureTextEntry />
        </ScrollView>
      </KeyboardAvoidingView>
    </SafeAreaView>
  );
}

const styles = StyleSheet.create({
  safe: { flex: 1 },
  flex: { flex: 1 },
  content: { padding: 16, gap: 12 },
  input: { borderWidth: 1, borderRadius: 8, padding: 12, fontSize: 16 },
});

Platform-Specific Component

import { Platform, StyleSheet, View, Text } from 'react-native';

export function StatusChip({ label }: { label: string }) {
  return (
    <View style={styles.chip}>
      <Text style={styles.label}>{label}</Text>
    </View>
  );
}

const styles = StyleSheet.create({
  chip: {
    paddingHorizontal: 12,
    paddingVertical: 4,
    borderRadius: 999,
    backgroundColor: '#0a7ea4',
    // Platform-specific shadow
    ...Platform.select({
      ios: { shadowColor: '#000', shadowOffset: { width: 0, height: 2 }, shadowOpacity: 0.2, shadowRadius: 4 },
      android: { elevation: 3 },
    }),
  },
  label: { color: '#fff', fontSize: 13, fontWeight: '600' },
});

Output Format

When implementing React Native features, deliver:

  1. Component code — TypeScript, with prop types defined
  2. Platform handling — Platform.select or .ios.tsx / .android.tsx splits as needed
  3. Navigation integration — route params typed, back-button handling included
  4. Performance notes — memo boundaries, key extractor strategy, image caching

Knowledge Reference

React Native 0.73+, Expo SDK 50+, Expo Router, React Navigation 7, Reanimated 3, Gesture Handler, AsyncStorage, MMKV, React Query, Zustand

Documentation

More skills from Jeffallan/claude-skills

  • Aangular-architectGenerates Angular 17+ standalone components, configures advanced routing with lazy loading and guards, implements NgRx state management, applies RxJS patterns, and optimizes bundle performance. Use when building Angular 17+ applications with standalone components or signals, setting up NgRx stores, establishing RxJS reactive patterns, performance tuning, or writing Angular tests for enterprise apps.
  • Aapi-designerUse when designing REST or GraphQL APIs, creating OpenAPI specifications, or planning API architecture. Invoke for resource modeling, versioning strategies, pagination patterns, error handling standards.
  • Aarchitecture-designerUse when designing new high-level system architecture, reviewing existing designs, or making architectural decisions. Invoke to create architecture diagrams, write Architecture Decision Records (ADRs), evaluate technology trade-offs, design component interactions, and plan for scalability. Use for system design, architecture review, microservices structuring, ADR authoring, scalability planning, and infrastructure pattern selection — distinct from code-level design patterns or database-only design tasks.
  • Aatlassian-mcpIntegrates with Atlassian products to manage project tracking and documentation via MCP protocol. Use when querying Jira issues with JQL filters, creating and updating tickets with custom fields, searching or editing Confluence pages with CQL, managing sprints and backlogs, setting up MCP server authentication, syncing documentation, or debugging Atlassian API integrations.
  • Achaos-engineerDesigns chaos experiments, creates failure injection frameworks, and facilitates game day exercises for distributed systems — producing runbooks, experiment manifests, rollback procedures, and post-mortem templates. Use when designing chaos experiments, implementing failure injection frameworks, or conducting game day exercises. Invoke for chaos experiments, resilience testing, blast radius control, game days, antifragile systems, fault injection, Chaos Monkey, Litmus Chaos.
  • Acli-developerUse when building CLI tools, implementing argument parsing, or adding interactive prompts. Invoke for parsing flags and subcommands, displaying progress bars and spinners, generating bash/zsh/fish completion scripts, CLI design, shell completions, and cross-platform terminal applications using commander, click, typer, or cobra.
  • Acloud-architectDesigns cloud architectures, creates migration plans, generates cost optimization recommendations, and produces disaster recovery strategies across AWS, Azure, and GCP. Use when designing cloud architectures, planning migrations, or optimizing multi-cloud deployments. Invoke for Well-Architected Framework, cost optimization, disaster recovery, landing zones, security architecture, serverless design.
  • Acode-documenterGenerates, formats, and validates technical documentation — including docstrings, OpenAPI/Swagger specs, JSDoc annotations, doc portals, and user guides. Use when adding docstrings to functions or classes, creating API documentation, building documentation sites, or writing tutorials and user guides. Invoke for OpenAPI/Swagger specs, JSDoc, doc portals, getting started guides.
  • Acode-reviewerAnalyzes code diffs and files to identify bugs, security vulnerabilities (SQL injection, XSS, insecure deserialization), code smells, N+1 queries, naming issues, and architectural concerns, then produces a structured review report with prioritized, actionable feedback. Use when reviewing pull requests, conducting code quality audits, identifying refactoring opportunities, or checking for security issues. Invoke for PR reviews, code quality checks, refactoring suggestions, review code, code quality. Complements specialized skills (security-reviewer, test-master) by providing broad-scope review across correctness, performance, maintainability, and test coverage in a single pass.
  • Acpp-proWrites, optimizes, and debugs C++ applications using modern C++20/23 features, template metaprogramming, and high-performance systems techniques. Use when building or refactoring C++ code requiring concepts, ranges, coroutines, SIMD optimization, or careful memory management — or when addressing performance bottlenecks, concurrency issues, and build system configuration with CMake.
  • Acsharp-developerUse when building C# applications with .NET 8+, ASP.NET Core APIs, or Blazor web apps. Builds REST APIs using minimal or controller-based routing, configures database access with Entity Framework Core, implements async patterns and cancellation, structures applications with CQRS via MediatR, and scaffolds Blazor components with state management. Invoke for C#, .NET, ASP.NET Core, Blazor, Entity Framework, EF Core, Minimal API, MAUI, SignalR.
  • Adatabase-optimizerOptimizes database queries and improves performance across PostgreSQL and MySQL systems. Use when investigating slow queries, analyzing execution plans, or optimizing database performance. Invoke for index design, query rewrites, configuration tuning, partitioning strategies, lock contention resolution.

All agent skills → · MCP servers