Native UI

Building native mobile UIs with Expo Router and React Native. Covers routing, navigation, styling, native controls, animations, and platform conventions following Apple Human Interface Guidelines.

Native UI with Expo Router

Patterns and conventions for building native mobile applications with Expo Router and React Native.

References

Consult these as needed:

• ./references/route-structure.md — Route conventions, dynamic routes, groups, folder organization
• ./references/tabs.md — Native tab bar with NativeTabs, iOS 26 features
• ./references/icons.md — SF Symbols with expo-symbols, icon names, animations, weights
• ./references/controls.md — Native iOS controls: Switch, Slider, SegmentedControl, DateTimePicker
• ./references/visual-effects.md — Blur effects (expo-blur) and liquid glass (expo-glass-effect)
• ./references/animations.md — Reanimated: entering, exiting, layout, scroll-driven, gestures
• ./references/search.md — Search bar with headers, useSearch hook, filtering patterns
• ./references/gradients.md — CSS gradients via experimental_backgroundImage (New Architecture only)
• ./references/media.md — Camera, audio, video, file saving
• ./references/storage.md — SQLite, AsyncStorage, SecureStore
• ./references/webgpu-three.md — 3D graphics and GPU visualizations with WebGPU/Three.js
• ./references/toolbar-and-headers.md — Stack headers and toolbar with buttons, menus, search bars (iOS)
• ./references/form-sheet.md — Form sheet presentation patterns

Running the App

Always try Expo Go first before creating custom builds.

1. Start with npx expo start and scan the QR code
2. Test features in Expo Go
3. Only create custom builds when required

When Custom Builds Are Required

Use npx expo run:ios/android or eas build only for:

• Local Expo modules (custom native code in modules/)
• Apple targets (widgets, app clips via @bacons/apple-targets)
• Third-party native modules not in Expo Go
• Custom native configuration beyond app.json

Expo Go supports all expo-* packages, Expo Router, Reanimated, Gesture Handler, push notifications, and deep links out of the box.

Installation

OpenClaw / Moltbot / Clawbot

bash

npx clawhub@latest install native-ui

---

Code Style

• Escape nested backticks and quotes correctly
• Always use import statements at the top of the file
• Use kebab-case for file names: comment-card.tsx
• Remove old route files when restructuring navigation
• No special characters in file names
• Configure tsconfig.json path aliases; prefer aliases over relative imports

Routes

See ./references/route-structure.md for detailed conventions.

• Routes belong in the app directory
• Never co-locate components, types, or utilities in app/ — this is an anti-pattern
• Always have a route matching /, possibly inside a group route

Library Preferences

Use	Instead of
expo-audio	expo-av
expo-video	expo-av
expo-symbols	@expo/vector-icons
react-native-safe-area-context	RN SafeAreaView
process.env.EXPO_OS	Platform.OS
React.use	React.useContext
expo-image	Intrinsic img element
expo-glass-effect	Custom glass backdrops

Never use deprecated modules: Picker, WebView, SafeAreaView, AsyncStorage (from RN core), or legacy expo-permissions.

---

Responsiveness

• Wrap root components in a scroll view
• Use <ScrollView contentInsetAdjustmentBehavior="automatic" /> instead of <SafeAreaView>
• Apply contentInsetAdjustmentBehavior="automatic" to FlatList and SectionList too
• Use flexbox instead of Dimensions API
• Prefer useWindowDimensions over Dimensions.get() for screen measurement

Behavior

• Use expo-haptics conditionally on iOS for delightful interactions
• Use views with built-in haptics (<Switch />, @react-native-community/datetimepicker)
• First child of a Stack route should almost always be a ScrollView with contentInsetAdjustmentBehavior="automatic"
• Prefer headerSearchBarOptions in Stack.Screen options for search bars
• Use <Text selectable /> on data that users may want to copy
• Format large numbers: 1.4M, 38k
• Never use intrinsic elements (img, div) outside webviews or Expo DOM components

---

Styling

Follow Apple Human Interface Guidelines.

General Rules

• Prefer flex gap over margin and padding
• Prefer padding over margin
• Always account for safe area via stack headers, tabs, or contentInsetAdjustmentBehavior="automatic"
• Ensure both top and bottom safe area insets are handled
• Inline styles preferred over StyleSheet.create unless reusing styles
• Add entering/exiting animations for state changes
• Use { borderCurve: 'continuous' } for rounded corners (not capsule shapes)
• Use navigation stack title instead of custom text headers
• On ScrollView, use contentContainerStyle for padding/gap (avoids clipping)
• CSS and Tailwind are not supported — use inline styles

Text Styling

• Add selectable prop to <Text/> elements showing important data or errors
• Use { fontVariant: 'tabular-nums' } on counters for alignment

Shadows

Use CSS boxShadow style prop. Never use legacy RN shadow or elevation styles.

tsx

<View style={{ boxShadow: "0 1px 2px rgba(0, 0, 0, 0.05)" }} />

Inset shadows are supported.

---

Navigation

Link

Use <Link href="/path" /> from expo-router for navigation.

tsx

import { Link } from 'expo-router';

<Link href="/path" />

<Link href="/path" asChild>
  <Pressable>...</Pressable>
</Link>

Include <Link.Preview> whenever possible to follow iOS conventions. Add context menus and previews frequently.

Stack

• Always use _layout.tsx files to define stacks
• Use Stack from expo-router/stack for native navigation stacks
• Set page titles in Stack.Screen options: options={{ title: "Home" }}

Context Menus

Add long-press context menus to Link components:

tsx

<Link href="/settings" asChild>
  <Link.Trigger>
    <Pressable><Card /></Pressable>
  </Link.Trigger>
  <Link.Menu>
    <Link.MenuAction title="Share" icon="square.and.arrow.up" onPress={handleShare} />
    <Link.MenuAction title="Block" icon="nosign" destructive onPress={handleBlock} />
    <Link.Menu title="More" icon="ellipsis">
      <Link.MenuAction title="Copy" icon="doc.on.doc" onPress={() => {}} />
      <Link.MenuAction title="Delete" icon="trash" destructive onPress={() => {}} />
    </Link.Menu>
  </Link.Menu>
</Link>

Link Previews

tsx

<Link href="/settings">
  <Link.Trigger>
    <Pressable><Card /></Pressable>
  </Link.Trigger>
  <Link.Preview />
</Link>

Can be combined with context menus.

Modal

Present a screen as a modal:

tsx

<Stack.Screen name="modal" options={{ presentation: "modal" }} />

Prefer this over custom modal components.

Sheet

Present as a dynamic form sheet:

tsx

<Stack.Screen
  name="sheet"
  options={{
    presentation: "formSheet",
    sheetGrabberVisible: true,
    sheetAllowedDetents: [0.5, 1.0],
    contentStyle: { backgroundColor: "transparent" },
  }}
/>

contentStyle: { backgroundColor: "transparent" } enables liquid glass on iOS 26+.

---

Common Route Structure

Standard app layout with tabs and stacks:

text

app/
  _layout.tsx        — <NativeTabs />
  (index,search)/
    _layout.tsx      — <Stack />
    index.tsx        — Main list
    search.tsx       — Search view

Root layout:

tsx

// app/_layout.tsx
import { NativeTabs, Icon, Label } from "expo-router/unstable-native-tabs";
import { Theme } from "../components/theme";

export default function Layout() {
  return (
    <Theme>
      <NativeTabs>
        <NativeTabs.Trigger name="(index)">
          <Icon sf="list.dash" />
          <Label>Items</Label>
        </NativeTabs.Trigger>
        <NativeTabs.Trigger name="(search)" role="search" />
      </NativeTabs>
    </Theme>
  );
}

Shared group layout:

tsx

// app/(index,search)/_layout.tsx
import { Stack } from "expo-router/stack";
import { PlatformColor } from "react-native";

export default function Layout({ segment }) {
  const screen = segment.match(/\((.*)\)/)?.[1]!;
  const titles: Record<string, string> = { index: "Items", search: "Search" };

  return (
    <Stack
      screenOptions={{
        headerTransparent: true,
        headerShadowVisible: false,
        headerLargeTitleShadowVisible: false,
        headerLargeStyle: { backgroundColor: "transparent" },
        headerTitleStyle: { color: PlatformColor("label") },
        headerLargeTitle: true,
        headerBlurEffect: "none",
        headerBackButtonDisplayMode: "minimal",
      }}
    >
      <Stack.Screen name={screen} options={{ title: titles[screen] }} />
      <Stack.Screen name="i/[id]" options={{ headerLargeTitle: false }} />
    </Stack>
  );
}