flutter_tts uses legacy Kotlin Gradle Plugin and triggers future Flutter build warning

[babak3389]

Description

When building my Flutter Android application, Flutter reports that flutter_tts applies the legacy Kotlin Gradle Plugin (KGP) configuration.

The application currently builds successfully, but Flutter warns that future Flutter versions may fail to build projects using plugins with this configuration.

Warning message

WARNING: Your app uses the following plugins that apply Kotlin Gradle Plugin (KGP): flutter_tts

Future versions of Flutter will fail to build if your app uses plugins that apply KGP.

Please check the changelogs of these plugins and upgrade to a version that supports Built-in Kotlin.

Environment

• Flutter version: [run flutter --version and paste the output]
• Dart version: [paste Dart version]
• flutter_tts version: 4.2.5
• Operating system: Windows
• Target platform: Android
• Android Gradle Plugin: [paste version if known]
• Gradle version: [paste version if known]
• Kotlin version: [paste version if known]

Steps to reproduce

1. Create or open a Flutter Android project.
2. Add the following dependency:

dependencies:
flutter_tts: ^4.2.5

3. Run:

flutter pub get
flutter build apk --debug

4. Observe the Kotlin Gradle Plugin compatibility warning.

Expected behavior

flutter_tts should use Flutter's current Built-in Kotlin compatibility approach and should not trigger a legacy KGP warning during the Android build.

Actual behavior

The build completes successfully, but Flutter reports that flutter_tts applies the legacy Kotlin Gradle Plugin configuration and may become incompatible with future Flutter releases.

Requested fix

Could you please migrate the Android part of flutter_tts to the current Flutter Built-in Kotlin approach and publish a compatible release?

It would also be helpful if the changelog documented the migration and the minimum supported Flutter/Android Gradle versions.

Thank you for maintaining this plugin.