# Expo (React Native, web target) (/getting-started/frameworks/expo)



Expo works with `WalletManagerProvider` and `autoDiscovery()`, but React Native
has no `localStorage`, so you supply an `AsyncStorage`-backed
[storage driver](/guides/custom-storage). This is the `demo-expo-web`
reference.

```ts title="src/async-storage-driver.ts"
import AsyncStorage from "@react-native-async-storage/async-storage";
import type { StorageDriver } from "@usebutr/core";

const asyncStorageDriver: StorageDriver = {
  getItem: (key) => AsyncStorage.getItem(key),
  setItem: (key, value) => AsyncStorage.setItem(key, value),
  removeItem: (key) => AsyncStorage.removeItem(key),
};

export { asyncStorageDriver };
```

```tsx title="src/wallet-provider.tsx"
import type { ReactNode } from "react";
import { WalletStorage } from "@usebutr/core";
import { WalletManagerProvider } from "@usebutr/react";
import { autoDiscovery } from "@usebutr/wallets";
import { asyncStorageDriver } from "./async-storage-driver";

const KEY_PREFIX = "butr-demo";

const discovery = autoDiscovery();

const storage = new WalletStorage({
  keyPrefix: KEY_PREFIX,
  persistent: asyncStorageDriver,
  session: asyncStorageDriver,
});

const WalletProvider = ({ children }: { children: ReactNode }) => (
  <WalletManagerProvider discovery={discovery} storage={storage} storageKeyPrefix={KEY_PREFIX}>
    {children}
  </WalletManagerProvider>
);

export { WalletProvider };
```

<Callout type="warn">
  `demo-expo-web` targets the **web** bundle (`expo start --web`), where browser wallet discovery
  works. Native iOS/Android wallet transports (deep links, in-app browsers) are out of scope for
  this provider; on native you'd pair through [WalletConnect](/connectors/walletconnect) instead.
</Callout>

<Callout type="info">
  **Source:** `apps/demo-expo-web/src/wallet-provider.tsx` in the [butr
  repository](https://github.com/pedroapfilho/usebutr/tree/main/apps/demo-expo-web). Run `pnpm dev   --filter=demo-expo-web` → `http://localhost:8081`. See [custom storage](/guides/custom-storage)
  for the session-storage caveat.
</Callout>