Flutter apps

The bothy package wraps the Rust engine as a native library. Building an app with it needs a Rust toolchain (rustup); the native code is compiled for each platform during the Flutter build.

dependencies:
  bothy: ^0.4.0

Open, write, watch

import 'package:bothy/bothy.dart';

await Bothy.initialize();
final db = await Bothy.open(
  path: '${supportDir.path}/notes.db',
  appId: 'com.example.notes',
  remote: BothyRemoteSpec.googleDriveAppData(
    (forceRefresh) => mySignIn.accessToken(refresh: forceRefresh),
  ),
  p2p: true,
);
await db.initOrJoin();

final notes = db.collection('notes');
await notes.put('n1', {'title': 'Hello', 'done': false});
await notes.patch('n1', {'done': true});
final note = await notes.get('n1');

notes.watch().listen((change) => refresh(change.id));
db.startAutoSync();

Google sign-in

The package never signs in by itself. Your app runs the OAuth flow, for example with google_sign_in on Android and iOS or a browser loopback on desktop, and gives Bothy a callback that returns an access token:

• with the drive.appdata scope for BothyRemoteSpec.googleDriveAppData;
• or with the drive.file scope for BothyRemoteSpec.googleDriveFolder(name).

Return null when the user is signed out. Bothy calls the callback with forceRefresh: true after Drive rejects a token. Create the clients as in Set up Google sign-in; on Android you need an Android client (package name and signing SHA-1) and a Web client.

Encryption

final db = await Bothy.open(..., encrypt: true, password: password); // first device
final db = await Bothy.open(..., password: password);                // other devices

Keep await db.exportKey() in flutter_secure_storage and open with key: next time. A wrong password throws BothyException with BothyErrorKind.wrongPassword. A database opened without a secret is locked: local reads and writes work, and sync throws BothyErrorKind.keyRequired until unlock.

Background sync

startAutoSync() syncs while the app runs. For sync while the app is closed, schedule db.sync() with WorkManager (Android) or BGTaskScheduler (iOS); the demo app shows both. Direct channels only run while the app is in the foreground.

The demo app

examples/flutter-notes is a complete notes app: sign-in on every platform, encryption, conflicts, a Robot screen and direct channels. Its README covers the OAuth client setup.