Build native mobile UI with React and Expo

This skill covers @expo/ui, a package that renders real native UI from React: SwiftUI on iOS and Jetpack Compose on Android. It starts with universal components (Host, Column, Row, Button, Text, List, and more imported from the @expo/ui root) that produce one component tree running unmodified across iOS, Android, and web from a single source - Compose on Android, SwiftUI on iOS, react-native-web/react-dom on web - with no platform file splits. When the universal layer is missing a component or modifier, or platform-specific behavior/optimization is needed, it drops to the platform-specific layers imported from @expo/ui/swift-ui (iOS-only) or @expo/ui/jetpack-compose (Android-only), which requires splitting code into .ios.tsx/.android.tsx files or branching on Platform.OS. It also ships drop-in, API-compatible replacements for popular React Native community UI libraries - such as @gorhom/bottom-sheet and @react-native-community/datetimepicker - imported from @expo/ui/community/<name>, as a migration path distinct from the universal-vs-platform decision. The universal layer requires Expo SDK 56+; drop-in replacements and the platform-specific layers also work on SDK 55. On SDK 56, @expo/ui runs directly in Expo Go via npx expo start, with no custom dev build required; older SDKs need a dev client built first via npx expo run:ios/npx expo run:android.

Use it whenever building native UI with @expo/ui in an Expo or React Native app - whether reaching for universal cross-platform components, a platform-specific SwiftUI/Jetpack Compose layer, or a drop-in replacement for an existing RN community UI library. Work down the decision order it specifies: try universal components first, and only move to platform-specific imports when the universal layer genuinely lacks what's needed. Do NOT import @expo/ui/swift-ui or @expo/ui/jetpack-compose in a file that can run on the other platform - this crashes at runtime with "Unable to get view config" errors - and never place platform-specific trees inside app/, since Expo Router does not support platform extensions for route files; isolate them in components/ instead.

Inputs: the UI need (a specific native component or interaction) and the Expo SDK version in use, since the universal layer specifically requires SDK 56+. Outputs: a component tree - universal, platform-specific, or a drop-in replacement - wrapped in Host (always imported from the universal @expo/ui package root, never from a platform-specific sub-package), running as real SwiftUI or Jetpack Compose under the hood.

npx expo install @expo/ui

Built directly on SwiftUI (iOS) and Jetpack Compose (Android) as the native rendering layers, with a web fallback via react-native-web/react-dom. Ships drop-in replacements for RN community libraries including @gorhom/bottom-sheet and @react-native-community/datetimepicker. Works inside Expo Go on SDK 56+; requires a custom dev client (npx expo run:ios/run:android) on SDK 55.

Expo/React Native developers who want native iOS and Android look-and-feel without maintaining separate native codebases, and teams migrating off existing RN community UI libraries toward native-rendered equivalents.