react-native-expo

# React Native Expo (0.76-0.82+ / SDK 52+)

**Status**: Production Ready
**Last Updated**: 2026-01-21
**Dependencies**: Node.js 20.19.4+, Expo CLI, Xcode 16.1+ (iOS)
**Latest Versions**: react-native@0.81.5, expo@~54.0.31, react@19.2.3

---

## Quick Start (15 Minutes)

### 1. Create New Expo Project (RN 0.76+)

```bash
# Create new Expo app with React Native 0.76+
npx create-expo-app@latest my-app

cd my-app

# Install latest dependencies
npx expo install react-native@latest expo@latest
```

**Why this matters:**
- Expo SDK 52+ uses React Native 0.76+ with New Architecture enabled by default
- New Architecture is **mandatory** in React Native 0.82+ (cannot be disabled)
- Hermes is the only supported JavaScript engine (JSC removed from Expo Go)

### 2. Verify New Architecture is Enabled

```bash
# Check if New Architecture is enabled (should be true by default)
npx expo config --type introspect | grep newArchEnabled
```

**CRITICAL:**
- React Native 0.82+ **requires** New Architecture - legacy architecture completely removed
- If migrating from 0.75 or earlier, upgrade to 0.76-0.81 first to use the interop layer
- Never try to disable New Architecture in 0.82+ (build will fail)

### 3. Start Development Server

```bash
# Start Expo dev server
npx expo start

# Press 'i' for iOS simulator
# Press 'a' for Android emulator
# Press 'j' to open React Native DevTools (NOT Chrome debugger!)
```

**CRITICAL:**
- Old Chrome debugger removed in 0.79 - use React Native DevTools instead
- Metro terminal no longer streams `console.log()` - use DevTools Console
- Keyboard shortcuts 'a'/'i' work in CLI, not Metro terminal

---

## Critical Breaking Changes (Dec 2024+)

### 🔴 New Architecture Mandatory (0.82+)

**SDK Timeline:**
- **Expo SDK 54** (React Native 0.81): Last release supporting Legacy Architecture
- **Expo SDK 55** (React Native 0.83): New Architecture mandatory, Legacy completely removed

**What Changed:**
- **0.76-0.81 / SDK 52-54**: New Architecture default, legacy