Expo UI Jetpack Compose

The instructions in this skill apply to SDK 55 only. For other SDK versions, refer to the Expo UI Jetpack Compose docs for that version for the most accurate information.

Installation

npx expo install @expo/ui

A native rebuild is required after installation (npx expo run:android).

Instructions

• Expo UI's API mirrors Jetpack Compose's API. Use Jetpack Compose and Material Design 3 knowledge to decide which components or modifiers to use. If you need deeper Jetpack Compose or Material 3 guidance (e.g. which component to pick, layout patterns, theming), spawn a subagent to research Jetpack Compose and Material Design 3 best practices.
• Components are imported from @expo/ui/jetpack-compose, modifiers from @expo/ui/jetpack-compose/modifiers.
• Always read the .d.ts type files to confirm the exact API before using a component or modifier. Run node -e "console.log(path.dirname(require.resolve('@expo/ui/jetpack-compose')))" to locate the package, then read the relevant {ComponentName}/index.d.ts files. This is the most reliable source of truth.
• When about to use a component, fetch its docs to confirm the API - https://docs.expo.dev/versions/v55.0.0/sdk/ui/jetpack-compose/{component-name}/index.md
• When unsure about a modifier's API, refer to the docs - https://docs.expo.dev/versions/v55.0.0/sdk/ui/jetpack-compose/modifiers/index.md
• Every Jetpack Compose tree must be wrapped in Host. Use <Host matchContents> for intrinsic sizing, or <Host style={{ flex: 1 }}> when you need explicit size (e.g. as a parent of LazyColumn). Example:

import { Host, Column, Button, Text } from "@expo/ui/jetpack-compose";
import { fillMaxWidth, paddingAll } from "@expo/ui/jetpack-compose/modifiers";

<Host matchContents>
  <Column verticalArrangement={{ spacedBy: 8 }} modifiers={[fillMaxWidth(), paddingAll(16)]}>
    <Text style={{ typography: "titleLarge" }}>Hello</Text>
    <Button onPress={() => alert("Pressed!")}>Press me</Button>
  </Column>
</Host>;

Key Components

• LazyColumn — Use instead of react-native ScrollView/FlatList for scrollable lists. Wrap in <Host style={{ flex: 1 }}>.
• Icon — Use <Icon source={require('./icon.xml')} size={24} /> with Android XML vector drawables. To get icons: go to Material Symbols, select an icon, choose the Android platform, and download the XML vector drawable. Save these as .xml files in your project's assets/ directory (e.g. assets/icons/wifi.xml). Metro bundles .xml assets automatically — no metro config changes needed.