Rerune Flutter OTA

Update ARB translation files at runtime (mobile, web, desktop) using a manifest endpoint. The SDK downloads new translations, caches them, and rebuilds Localizations without restarting the app.

Features

  • Manifest-driven ARB updates with ETag support
  • Local cache for offline fallback
  • Hot swap translations without app restart
  • Works on mobile, web, and desktop

Getting started

Add the package to your pubspec.yaml:

dependencies:
  rerune_flutter_ota: ^0.0.1

Add your rerune.json to the app root and include it as an asset:

flutter:
  assets:
    - rerune.json
    - lib/languages/I10n/

If you pass apiKey to the controller, the file is optional and ignored.

When translations_path is set in rerune.json, the SDK automatically loads seed bundles from app_<code>.arb files in that folder.

Seamless AppLocalizations integration

The SDK can overlay OTA translations on top of your generated AppLocalizations API, so your widgets keep using:

Text(AppLocalizations.of(context)!.helloWorld)

  1. Generate Flutter localizations (flutter gen-l10n).

  2. Generate the Rerune wrapper:

dart run rerune_flutter_ota:generate \
  --input lib/l10n/app_localizations.dart \
  --output lib/l10n/rerune_app_localizations.dart
  1. Wire the generated delegate in your app root:
import 'l10n/app_localizations.dart';
import 'l10n/rerune_app_localizations.dart';

final controller = OtaLocalizationController(
  supportedLocales: const [Locale('en'), Locale('es')],
  // Optional: override api_key from rerune.json
  // apiKey: 'your-api-key',
  // Optional: override project_id/platform from rerune.json
  // projectId: 'your-project-id',
  // platform: 'flutter',
);

await controller.initialize();

return OtaTypedLocalizationBuilder<AppLocalizations>(
  controller: controller,
  delegateFactory: (context, controller, revision) {
    return ReruneAppLocalizationsDelegate(
      controller: controller,
      revision: revision,
    );
  },
  builder: (context, delegate) {
    return MaterialApp(
      localizationsDelegates:
          ReruneAppLocalizationsSetup.localizationsDelegates(delegate),
      supportedLocales: ReruneAppLocalizationsSetup.supportedLocales,
      home: MyHomePage(),
    );
  },
);

OtaLocalizationController always uses https://rerune.io/api for manifest and translation requests.

Manifest format

{
  "version": 7,
  "locales": {
    "en": {
      "version": 3,
      "url": "https://rerune.io/api/sdk/projects/<projectId>/translations/flutter/en",
      "sha256": "..."
    },
    "es": {
      "version": 2,
      "url": "https://rerune.io/api/sdk/projects/<projectId>/translations/flutter/es"
    }
  }
}

Manifest URL is derived internally from https://rerune.io/api + project_id: /sdk/projects/{projectId}/translations/manifest?platform={platform}.

If a locale entry omits url, the SDK constructs it using: /sdk/projects/{projectId}/translations/{platform}/{locale} with values from rerune.json or controller overrides.

Libraries

rerune_flutter_ota