android-gradle-logic

Create a build-logic directory included as a composite build via includeBuild in settings.gradle.kts, then write convention plugins that apply common configuration. Modules apply them with a single plugins block alias instead of repeating configuration.

Apply the kotlin-dsl plugin in build-logic/convention/build.gradle.kts, write a class implementing Plugin<Project>, and register it in the gradlePlugin block with a stable ID. Declare the ID in libs.versions.toml so modules can reference it with alias(libs.plugins...).

Yes, but not automatically. In build-logic/settings.gradle.kts, create a version catalog in dependencyResolutionManagement that points to the root gradle/libs.versions.toml file using from(files(...)).

The examples target AGP 8. AGP 9 removes the standalone org.jetbrains.kotlin.android plugin, drops BaseExtension and old variant APIs, moves kotlinOptions to kotlin { compilerOptions {} }, and breaks kapt, so convention plugins touching these need migration.

Use convention plugins once you have multiple modules sharing compileSdk, minSdk, toolchains, or Compose setup. They define configuration once, so updates propagate to every module without editing each build file.