Phrase Strings OTA for Flutter

Library for Phrase Strings over-the-air translations.


Important: this library depends on 0.18.0 version of Flutter's intl library. Please follow this guide to add localizations support to your app.

Add the phrase dependency to your pubspec.yaml:

  phrase: ^2.0.0
  intl: ^0.18.0
    sdk: flutter

  generate: true

Just like intl library, phrase uses code generation to process your ARB files.

To keep it up-to-date, just run this command:

$ flutter pub run phrase

or if you're using build_runner:

$ flutter pub run build_runner watch


Initialize Phrase Strings in your main.dart file:

import 'package:flutter/material.dart';
import 'package:flutter_gen/gen_l10n/app_localizations.dart';
import 'package:flutter_gen/gen_l10n/phrase_localizations.dart';
import 'package:phrase/phrase.dart';

void main() {
  Phrase.setup("[DISTRIBUTION_ID]", "[ENVIRONMENT_ID]");

class MyApp extends StatelessWidget {
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      localizationsDelegates: PhraseLocalizations.localizationsDelegates,
      supportedLocales: PhraseLocalizations.supportedLocales,

That's it! You can access your messages just like you did before:


But now your app will check for updated translations in Phrase regularly and download them in the background.


Update behavior

By default, Phrase Strings will update OTA translations every time the app launches.

You can disable this behavior:

Phrase.setup("[DISTRIBUTION_ID]", "[ENVIRONMENT_ID]", checkForUpdates: false);

and trigger updates manually:

Phrase.updateTranslations(context).then((_) => print("Done!"));

Api host

By default phrase uses european host. But we can set it to use the US api host if needed. To do so, we just have to set it up during initial setup:

Phrase.setup("[DISTRIBUTION_ID]", "[ENVIRONMENT_ID]", host:;

Custom app version

The SDK will use the app version by default to return a release which matches the release constraints for the min and max version. The app version has to use semantic versioning otherwise no translation update will be returned. In case your app does not use semantic versioning it is possible to manually override the app version:

Phrase.setup("[DISTRIBUTION_ID]", "[ENVIRONMENT_ID]", customAppVersion: "1.2.3");

Access OTA translation with key string literal

You can access the OTA translation using a string literal containing the translation key. To get the translation value for

  "textSimple": "Simple Text"

you can get the value using


instead of


It's also possible to use this method using translation parameters. To get the translation value for

  "textWithDate": "Text with date: {date}",
  "@textWithDate": {
    "description": "Text with date parameter",
    "placeholders": {
      "date": {
        "type": "DateTime",
        "format": "yMd"

you can get the value using

    args: {'date': DateTime.utc(1996, 7, 10)},

instead of

    DateTime.utc(1996, 7, 10),

Notice that the argument key value must match the translation placeholder name, otherwise you will get a runtime error.

Given that getText is a method in a class extension on AppLocalizations you have to import the file phrase_localizations.dart from the same location as it's done in setting up the App's localization. Either from package:flutter_gen/gen_l10n/phrase_localizations.dart or the one defined in l10n.yaml file's output-dir when using synthetic-package set to false. For example package:flutter_sdk_example/l10n/gen/phrase_localizations.dart.


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