Expo Router

Overview

File-based routing for React Native using Expo Router 6.x. Maps file system structure in the app/ directory to navigation screens. Supports Stack and Tab navigators, route groups, dynamic parameters, and nested layouts.

Install: Included with Expo SDK 54+. Ensure expo-router is in dependencies.

Workflows

Setting up routing:

1. Create app/_layout.tsx as root layout (providers, global chrome)
2. Create route group directories: app/(demo)/, app/(auth)/
3. Add _layout.tsx in each group for group-specific navigation
4. Add index.tsx for default screens
5. Add [param].tsx for dynamic routes
6. Add +not-found.tsx for 404 handling

Adding a new screen:

1. Create file in appropriate route group
2. Export default React component
3. Configure screen options in parent _layout.tsx or via <Stack.Screen options={...} />
4. Navigate using useRouter() or <Link>

Guidance

File Conventions

File	Purpose
_layout.tsx	Layout wrapper for directory (providers, navigators)
index.tsx	Default screen for directory
[param].tsx	Dynamic route segment
[...catchAll].tsx	Catch-all route
+not-found.tsx	404 screen
(group)/	Route group (no URL segment)

Root Layout Pattern

The root _layout.tsx is the entry point. Use it for global providers:

app/_layout.tsx → GestureHandlerRootView > SafeAreaProvider > Context > Stack

Keep the root layout thin — push chrome (tabs, headers) into group layouts.

Route Groups

Route groups (name)/ organize screens without affecting the URL path. Common pattern:

app/
├── _layout.tsx          # Root: providers + Stack
├── (demo)/
│   ├── _layout.tsx      # Tabs or Stack for demo scenes
│   ├── index.tsx        # Home screen
│   └── [id].tsx         # Detail screen
└── +not-found.tsx

Navigation

• Programmatic: const router = useRouter() → router.push('/detail/123'), router.back()
• Declarative: <Link href="/detail/123"> component
• Params: const { id } = useLocalSearchParams<{ id: string }>()
• Redirect: <Redirect href="/login" /> for conditional routing

Screen Options

Configure screen presentation via layout or inline:

• In layout: <Stack.Screen name="detail" options={{ title: 'Detail', headerShown: false }} />
• Inline: <Stack.Screen options={{ presentation: 'modal' }} />
• Common options: title, headerShown, presentation ('card' | 'modal'), animation

Layout Nesting

Nest providers in root, chrome in groups:

• Root _layout.tsx: GestureHandlerRootView, SafeAreaProvider, theme context, <Stack />
• Group _layout.tsx: <Tabs /> or <Stack /> with screen options, header configuration

Best Practices

• Keep route files thin — delegate to view components in /components/views/
• Use route groups to separate concerns without affecting URLs
• Type route params with generics: useLocalSearchParams<{ id: string }>()
• Set headerShown: false when providing custom headers
• Use <Stack screenOptions={{ animation: 'slide_from_right' }} /> for consistent transitions
• Place shared providers (theme, data context) in root _layout.tsx
• Use +not-found.tsx for graceful 404 handling

Anti-Patterns

• Placing business logic in route files (keep them thin, delegate to components)
• Deeply nesting route groups beyond 2 levels
• Using React Navigation directly instead of Expo Router abstractions
• Hardcoding navigation paths as strings without a constants file for complex apps
• Forgetting to export default from route files (causes blank screens)
• Putting providers in group layouts when they should be in root layout