Expo Router

Overview

Expo Router brings file-based routing to React Native — the same pattern as Next.js but for mobile apps. Drop a file in app/, get a screen. Folder structure defines navigation hierarchy: stacks, tabs, drawers, and modals. Deep linking works automatically — every route has a URL. Build iOS, Android, and web from one codebase with the same routing system.

When to Use

• Building a React Native / Expo app that needs navigation
• Want file-based routing instead of manual React Navigation config
• Need deep linking and universal links without extra setup
• Building a universal app (iOS + Android + Web)
• Migrating from React Navigation to a simpler routing model

Instructions

Setup

npx create-expo-app@latest my-app --template tabs
cd my-app
npx expo start

File-Based Routes

app/
├── _layout.tsx          # Root layout (wraps all screens)
├── index.tsx            # / (home screen)
├── about.tsx            # /about
├── (tabs)/              # Tab navigation group
│   ├── _layout.tsx      # Tab bar configuration
│   ├── index.tsx        # First tab (home)
│   ├── explore.tsx      # Second tab
│   └── profile.tsx      # Third tab
├── settings/
│   ├── _layout.tsx      # Stack layout for settings
│   ├── index.tsx        # /settings
│   ├── account.tsx      # /settings/account
│   └── notifications.tsx # /settings/notifications
├── [id].tsx             # /123 (dynamic route)
├── post/
│   └── [slug].tsx       # /post/my-first-post
└── +not-found.tsx       # 404 screen

Root Layout

// app/_layout.tsx — Root layout with stack navigation
import { Stack } from "expo-router";

export default function RootLayout() {
  return (
    <Stack>
      <Stack.Screen name="(tabs)" options={{ headerShown: false }} />
      <Stack.Screen name="settings" options={{ title: "Settings" }} />
      <Stack.Screen
        name="modal"
        options={{ presentation: "modal", title: "Info" }}
      />
    </Stack>
  );
}

Tab Navigation

// app/(tabs)/_layout.tsx — Bottom tab bar
import { Tabs } from "expo-router";
import { Ionicons } from "@expo/vector-icons";

export default function TabLayout() {
  return (
    <Tabs screenOptions={{ tabBarActiveTintColor: "#007AFF" }}>
      <Tabs.Screen
        name="index"
        options={{
          title: "Home",
          tabBarIcon: ({ color }) => <Ionicons name="home" size={24} color={color} />,
        }}
      />
      <Tabs.Screen
        name="explore"
        options={{
          title: "Explore",
          tabBarIcon: ({ color }) => <Ionicons name="compass" size={24} color={color} />,
        }}
      />
      <Tabs.Screen
        name="profile"
        options={{
          title: "Profile",
          tabBarIcon: ({ color }) => <Ionicons name="person" size={24} color={color} />,
        }}
      />
    </Tabs>
  );
}

Navigation and Dynamic Routes

// app/(tabs)/index.tsx — Home screen with navigation
import { Link, router } from "expo-router";
import { View, Text, Pressable, FlatList } from "react-native";

export default function HomeScreen() {
  const posts = usePosts();

  return (
    <View>
      {/* Declarative navigation */}
      <Link href="/about">About</Link>
      <Link href="/settings">Settings</Link>
      <Link href="/post/hello-world">My Post</Link>

      {/* Programmatic navigation */}
      <Pressable onPress={() => router.push("/settings/account")}>
        <Text>Go to Account</Text>
      </Pressable>

      {/* Dynamic routes */}
      <FlatList
        data={posts}
        renderItem={({ item }) => (
          <Link href={`/post/${item.slug}`}>
            <Text>{item.title}</Text>
          </Link>
        )}
      />
    </View>
  );
}

// app/post/[slug].tsx — Dynamic route screen
import { useLocalSearchParams } from "expo-router";

export default function PostScreen() {
  const { slug } = useLocalSearchParams<{ slug: string }>();
  const post = usePost(slug);

  return (
    <View>
      <Text style={{ fontSize: 24 }}>{post?.title}</Text>
      <Text>{post?.content}</Text>
    </View>
  );
}

Deep Linking (Automatic)

// app.json — Deep linking just works
{
  "expo": {
    "scheme": "myapp",
    "web": { "bundler": "metro" }
  }
}

Every route automatically gets a URL:

• myapp:// → Home screen
• myapp://post/hello-world → Post screen
• https://myapp.com/post/hello-world → Same screen (universal links)

Examples

Example 1: Build a social media app navigation

User prompt: "Set up navigation for a social app — tabs for feed/search/profile, stack for post details, and modal for creating posts."

The agent will create tab layout, nested stack routes, and a modal route with proper animations and deep linking.

Example 2: Add authentication flow

User prompt: "Add login/signup screens that show before the main app tabs."

The agent will create a route group for auth screens, use layout redirection based on auth state, and protect tab routes.

Guidelines

• File = route — app/about.tsx = /about screen
• _layout.tsx for navigation containers — Stack, Tabs, Drawer
• (group) for route groups — organize without affecting URL
• [param] for dynamic routes — access via useLocalSearchParams
• Deep linking is automatic — every route has a URL
• Link for declarative, router for programmatic — navigation
• +not-found.tsx for 404 — catches unmatched routes
• Typed routes — href autocompletes with TypeScript
• Web support — same routes work on web with expo-router
• presentation: "modal" in options — for modal screens