react-native

A set of coding guidelines for building React Native mobile apps with Expo, a toolchain for running and packaging React Native projects.

In plain words
What is it for?
Use it when creating or reviewing Expo mobile apps, including their screens, routes, shared components, login flows, and data access.
Why use it?
It gives a consistent project layout and recommended choices for navigation, styling, state, fonts, and app screens.

Cursor rule

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 rules/renvia-code/best-cursor-rules/react-native
Clone the repo
git clone --depth 1 https://github.com/Renvia-code/best-cursor-rules
Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 2,650 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 $0.00000 $0.02650
Opus 5 $0.00000 $0.01325
Sonnet 5 $0.00000 $0.00530
Haiku 4.5 $0.00000 $0.00265

Measured yesterday against content hash a28b4e777ec2, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

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 yesterday.

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.

rules/mobile/react-native.mdc · 479 lines

How it starts

The opening of the file, as written. The whole thing — 479 lines — stays where its author put it; the contents beside it link to each section on GitHub.

React Native (Expo) Best Practices

Overview

Aspect Recommendation
Framework Expo SDK 54+
Router Expo Router (file-based)
Styling NativeWind (Tailwind) or StyleSheet
State Zustand or React Context
Navigation Stack, Tabs, Drawer via Expo Router

Project Structure

app/
├── (tabs)/                 # Tab navigator group
│   ├── _layout.tsx         # Tab layout config
│   ├── index.tsx           # Home tab
│   └── profile.tsx         # Profile tab
├── (auth)/                 # Auth flow group
│   ├── _layout.tsx
│   ├── login.tsx
│   └── register.tsx
├── [id].tsx                # Dynamic route
├── _layout.tsx             # Root layout
├── +not-found.tsx          # 404 page
└── modal.tsx               # Modal screen
components/
├── ui/                     # Reusable UI components
└── ...
hooks/
├── useAuth.ts
└── ...
lib/
├── api.ts
└── storage.ts

Expo Router Navigation

Root Layout

// app/_layout.tsx
import { Stack } from 'expo-router'
import { useFonts } from 'expo-font'
import * as SplashScreen from 'expo-splash-screen'
import { useEffect } from 'react'

SplashScreen.preventAutoHideAsync()

export default function RootLayout() {
  const [loaded] = useFonts({
    SpaceMono: require('../assets/fonts/SpaceMono-Regular.ttf'),
  })

  useEffect(() => {
    if (loaded) SplashScreen.hideAsync()
  }, [loaded])

  if (!loaded) return null

  return (
    <Stack>
      <Stack.Screen name="(tabs)" options={{ headerShown: false }} />
      <Stack.Screen name="modal" options={{ presentation: 'modal' }} />
    </Stack>
  )
}

Tab Navigator

// app/(tabs)/_layout.tsx
import { Tabs } from 'expo-router'
import { Ionicons } from '@expo/vector-icons'

export default function TabLayout() {
  return (
    <Tabs screenOptions={{ tabBarActiveTintColor: '#007AFF' }}>
      <Tabs.Screen
        name="index"
        options={{
          title: 'Home',
          tabBarIcon: ({ color, size }) => (
            <Ionicons name="home" size={size} color={color} />
          ),
        }}
      />
      <Tabs.Screen
        name="profile"
        options={{
          title: 'Profile',
          tabBarIcon: ({ color, size }) => (
            <Ionicons name="person" size={size} color={color} />
          ),
        }}
      />
    </Tabs>
  )
}

Read the full file on GitHub · 479 lines

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. yesterday First seen · 479 lines · 0 tokens per session scan A a28b4e777ec2

Subscribe to this mod's changes

react-native is a cursor rule published in the GitHub repository Renvia-code/best-cursor-rules (12 stars, last pushed 9mo ago), licensed CC0-1.0. It costs nothing until one of its globs matches a file; then it loads 2,650 tokens. 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.