Expo

Capacitor renders every screen in a WebView, which is the right default. Expo earns its place when a screen needs what only native views can do:

If none of these apply to your app, stay with Capacitor.

Web routes are not converted to React Native. A React, Svelte, Vue, Angular, HTML or HTMX page is packaged and rendered exactly as in the Capacitor app. Only the modules you list use React Native.

Everything else in mobile works the same for both engines. routes.native maps a path pattern to a React Native module, relative to your project root. The generated app uses Expo SDK 57.

import { defineConfig } from '@absolutejs/absolute';

export default defineConfig({
  mobile: {
    engine: 'expo',
    appId: 'com.example.shop',
    appName: 'Shop',
    server: { productionOrigin: 'https://shop.example.com' },
    routes: {
      native: {
        '/scanner': './mobile/native/scanner.tsx',
        '/products/:productId': './mobile/native/product.tsx',
        '/files/*': './mobile/native/files.tsx'
      }
    }
  }
});

A native route is a React Native component whose props come from your existing server route. You do not write an API for it: the handler that renders the page on the web returns the same props to the app.

// The same handler serves the web page and the native route's pageProps
.get('/products/:productId', async ({ params, request }) =>
  handleReactPageRequest({
    index: asset(manifest, 'ProductIndex'),
    Page: Product,
    props: await loadProduct(params.productId),
    request
  })
)

// mobile/native/product.tsx
import { FlatList, Pressable, Text } from 'react-native';
import type { AbsoluteNativeRouteProps } from '@absolutejs/absolute/mobile';
import type { ProductPageProps } from '../../src/frontend/pages/Product';

export default function Product({
  pageProps,
  params,
  reload
}: AbsoluteNativeRouteProps<ProductPageProps, { productId: string }>) {
  return (
    <FlatList
      data={pageProps.variants}
      keyExtractor={(variant) => variant.id}
      ListHeaderComponent={<Text>{pageProps.name} #{params.productId}</Text>}
      onRefresh={reload}
      refreshing={false}
      renderItem={({ item }) => (
        <Pressable>
          <Text>{item.label}</Text>
        </Pressable>
      )}
    />
  );
}

Your code does not change. Native routes and web routes both use @absolutejs/auth/client, @absolutejs/sync and @absolutejs/devices; the Expo app installs these implementations for you, as soon as your package.json lists the package.

Push uses the device's APNs or FCM token directly and registers it with your server exactly as in the Capacitor app; see Push notifications.

Web routes call a fixed list of native methods: device features, HTTP, sign-in and Sync. Nothing else on the native side is reachable from a page.

Sync over the bridge uses the default JSON serializer.

bun dev generates the Expo project, offers to install the pinned SDK and Android toolchain, and starts Metro, the development client and your server together. It rebuilds the native app when your config, package.json or lockfile changes.

bun dev                            # Metro, the dev client and your server together
bun dev --android-device emulator-5554
bun dev --ios-device "iPhone 16"

iOS needs macOS, or a Mac paired with absolute mobile pair mac. Development covers devices, HTTPS and the remote Mac.

Store builds, the release doctor, certification and publishing use the same commands as Capacitor. Each build regenerates the native project from scratch, so nothing left over from development reaches the store.

bunx absolute mobile build android src/backend/server.ts
bunx absolute mobile build ios src/backend/server.ts
bunx absolute mobile publish android --play-track internal

Over-the-air updates use the standard expo-updates client against your own AbsoluteJS server, with an RSA code-signing certificate built into the app. Over-the-air updates covers keys and rollout.