[AGP 9] Add Docs to Migrate Android Build files to Sucessfully Build on AGP 9 #179914
Description
Overview
Gradle files in the android/app directory of a Flutter app project will be changed. A signficant change includes removing applying the Kotlin Gradle Plugin (kotlin-android). This work is discussed in more detail in the following issues/PRs:
In a future release, new flutter created apps will use the updated gradle file templates automatically. Existing apps aren't migrated though. Doing so automatically (using the tool's Migrator API) would be hard to do and error prone, and even then it would only work for projects that didn't substantially modify the buildscripts (which most apps do at some point).
This issue is about writing a migration guide where all these changes would be explained, so developers can easily update the native buildscripts.
Changes
Below is a summary of what default Gradle build files look like in a few latest Flutter versions. They're taken from the default app generated with flutter create example.
A migration guide should take into account that different apps were generated with different versions of Flutter.
Flutter 3.38
Released on Nov 12th, 2025.
Using a Flutter version before the fist stable release of AGP 9.0.0.
android/app/build.gradle.kts
plugins {
id("com.android.application")
id("kotlin-android")
// The Flutter Gradle Plugin must be applied after the Android and Kotlin Gradle plugins.
id("dev.flutter.flutter-gradle-plugin")
}
android {
namespace = "com.example.brand_new"
compileSdk = flutter.compileSdkVersion
ndkVersion = flutter.ndkVersion
compileOptions {
sourceCompatibility = JavaVersion.VERSION_17
targetCompatibility = JavaVersion.VERSION_17
}
kotlinOptions {
jvmTarget = JavaVersion.VERSION_17.toString()
}
defaultConfig {
// TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
applicationId = "com.example.brand_new"
// You can update the following values to match your application needs.
// For more information, see: https://flutter.dev/to/review-gradle-config.
minSdk = flutter.minSdkVersion
targetSdk = flutter.targetSdkVersion
versionCode = flutter.versionCode
versionName = flutter.versionName
}
buildTypes {
release {
// TODO: Add your own signing config for the release build.
// Signing with the debug keys for now, so `flutter run --release` works.
signingConfig = signingConfigs.getByName("debug")
}
}
}
flutter {
source = "../.."
}android/gradle.properties
org.gradle.jvmargs=-Xmx8G -XX:MaxMetaspaceSize=4G -XX:ReservedCodeCacheSize=512m -XX:+HeapDumpOnOutOfMemoryError
android.useAndroidX=trueSome Future Flutter Version
TBD Release date. Probably sometime early next year
android/app/build.gradle.kts
plugins {
id("com.android.application")
// The Flutter Gradle Plugin must be applied after the Android and Kotlin Gradle plugins.
id("dev.flutter.flutter-gradle-plugin")
}
android {
namespace = "com.example.brand_new"
compileSdk = flutter.compileSdkVersion
ndkVersion = flutter.ndkVersion
compileOptions {
sourceCompatibility = JavaVersion.VERSION_17
targetCompatibility = JavaVersion.VERSION_17
}
kotlin {
compilerOptions {
jvmTarget = org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17
}
}
defaultConfig {
// TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
applicationId = "com.example.brand_new"
// You can update the following values to match your application needs.
// For more information, see: https://flutter.dev/to/review-gradle-config.
minSdk = flutter.minSdkVersion
targetSdk = flutter.targetSdkVersion
versionCode = flutter.versionCode
versionName = flutter.versionName
}
buildTypes {
release {
// TODO: Add your own signing config for the release build.
// Signing with the debug keys for now, so `flutter run --release` works.
signingConfig = signingConfigs.getByName("debug")
}
}
}
flutter {
source = "../.."
}android/gradle.properties
org.gradle.jvmargs=-Xmx8G -XX:MaxMetaspaceSize=4G -XX:ReservedCodeCacheSize=512m -XX:+HeapDumpOnOutOfMemoryError
android.useAndroidX=true
android.newDsl=false