NDK Mobile

A React Native/Expo implementation of NDK (Nostr Development Kit) that provides a complete toolkit for building Nostr applications on mobile platforms.

Features

• 🔐 Multiple signer implementations (NIP-07, NIP-46, Private Key)
• 💾 SQLite-based caching for offline support
• 🔄 Subscription management with automatic reconnection
• 📱 React Native and Expo compatibility
• 🪝 React hooks for easy state management
• 👛 Integrated wallet support

Installation

npm install @nostr-dev-kit/ndk-mobile

Usage

When using this library don't import @nostr-dev-kit/ndk directly, instead import @nostr-dev-kit/ndk-mobile. ndk-mobile exports the same classes as ndk, so you can just swap the import.

Initialization

Initialize NDK using the init function, probably when your app loads.

function App() {
    const { ndk, init: initializeNDK } = useNDK();

    useEffect(() => {
        initializeNDK({
            /* Any parameter you'd want to pass to NDK */
            explicitRelayUrls: [...],
            // ...
        }
    }, []);
}

Settings

Throughout the use of a normal app, you will probably want to store some settings, such us, the user that is logged in. ndk-mobile can take care of this for you automatically if you pass a settingsStore to the initialization. For example, using expo-secure-store you can:

import * as SecureStore from 'expo-secure-store';

const settingsStore = {
    get: SecureStore.getItemAsync,
    set: SecureStore.setItemAsync,
    delete: SecureStore.deleteItemAsync,
    getSync: SecureStore.getItem,
};

// and then, when you initialiaze NDK:
initializeNDK({
    ......,
    settingsStore
})

Now, once your user logs in, their login information will be stored locally so when your app restarts, the user will be logged in automatically.

useNDK()

useNDK() provides access to the ndk instance and some other useful information.

function LoginScreen() {
    const { ndk, login } = useNDK();
    const currentUser = useNDKCurrentUser();

    useEffect(() => {
        if (currentUser) alert("you are now logged in as ", +currentUser.pubkey);
    }, [currentUser]);

    return <Button onPress={() => login(withPayload("nsec1..."))} title="Login" />;
}

Example

For a real application using this look at Olas.