Migrate AGP 8.11.* to AGP 9.0.0 for Kotlin Multiplatform

Table Of Contents

Step: 1 AGP Assistant Support
Step 2. Set up the Android Gradle Library Plugin for KMP
Step 3 Removing Gradle 9.0.0 properties & Enabling newDSL & buildInKotlin
Reference:

Step: 1 AGP Assistant Support

First, let take a advantage of AGP upgrade Assistant for the migration, which will simply update the correct versions associated with newly available AGPs. Chose the latest version and use wizard to complete the processs

In the end, you would expected to see some changes in gradle.properites. We needs to work on enabling these flags properly later.

gradle.properites.

android.builtInKotlin=false
android.newDsl=false

gradle-wrapper.properties

//OLD
distributionUrl=https\://services.gradle.org/distributions/gradle-8.14.3-bin.zip
//NEW
distributionUrl=https\://services.gradle.org/distributions/gradle-9.3.1-bin.zip

libs.versions.toml

// OLD
[versions]
agp = "8.11.2"
//NEW
[versions]
agp = "9.0.0"

Feel free to use github copilot/gemini to update rest of the library versions in .toml file. But, it is optional.

Step 2. Set up the Android Gradle Library Plugin for KMP

Separate Android Module, if it’s not separated before

I’ve used Android Studio Panda 1 to create a Kotlin Multimodule app, which doesn’t have separate module for android

OLD Folder Strcuture

New Folder Structure:

Steps to create androidApp folder

Create new ‘androidApp/src’ folder and move all the files and folders available in composeApp/src/androidMain to androidApp/src/main except Platform.android.kt file
composeApp/src/androidMain/AndroidManifest.xml to empty like below as we move out MainActivity and app code to different folder

<?xml version="1.0" encoding="utf-8"?>
<manifest>
</manifest>

3. Update gradle files (Please refer this patch file and make the chances accordingly)

Now worries, if you don’t know how to read this files. Here (-) inidicates removed lines (+) indicate added lines.

===================================================================
diff --git a/composeApp/build.gradle.kts b/composeApp/build.gradle.kts
--- a/composeApp/build.gradle.kts	(revision 5e06b291e9ef02c2756175a0e63e9bbcf9d30b4d)
+++ b/composeApp/build.gradle.kts	(date 1770332337088)
@@ -1,11 +1,10 @@
// Removed this import, if exit
-import org.gradle.kotlin.dsl.implementation
 
 plugins {
     alias(libs.plugins.kotlinMultiplatform)
     // Convert android applicaiton to android library
-    alias(libs.plugins.androidApplication)
+    alias(libs.plugins.androidLibrary)
     alias(libs.plugins.composeMultiplatform)
     alias(libs.plugins.composeCompiler)
     alias(libs.plugins.composeHotReload)
@@ -69,26 +68,8 @@
 }
 
 android {
-    namespace = "com.piappstudio.digitaldiary"
+    namespace = "com.piappstudio.digitaldiary.shared"
     compileSdk = libs.versions.android.compileSdk.get().toInt()
     // Remove this defaultConfig which is applicable only for android apps. LIbrary doens't needs it.
-
-    defaultConfig {
-        applicationId = "com.piappstudio.digitaldiary"
-        minSdk = libs.versions.android.minSdk.get().toInt()
-        targetSdk = libs.versions.android.targetSdk.get().toInt()
-        versionCode = 1
-        versionName = "1.0"
-    }
-    packaging {
-        resources {
-            excludes += "/META-INF/{AL2.0,LGPL2.1}"
-        }
-    }
-    buildTypes {
-        getByName("release") {
-            isMinifyEnabled = false
-        }
-    }
     compileOptions {
         sourceCompatibility = JavaVersion.VERSION_11
         targetCompatibility = JavaVersion.VERSION_11
Index: settings.gradle.kts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/settings.gradle.kts b/settings.gradle.kts
// Very important, we telling the to consider and complile our new folder structure.
+include(":androidApp")
====

4. Add new build.gradle.kts & proguards-rules.pro in androidApp folder

plugins {
    alias(libs.plugins.kotlinMultiplatform)
    alias(libs.plugins.androidApplication)
    alias(libs.plugins.composeMultiplatform)
    alias(libs.plugins.composeCompiler)

}

kotlin {
    androidTarget()
    sourceSets {
        val androidMain by getting {
            dependencies {
                implementation(project(":composeApp"))

                implementation(libs.compose.uiToolingPreview)
                implementation(libs.androidx.activity.compose)

            }
        }
    }
}

android {
    compileSdk = libs.versions.android.compileSdk.get().toInt()
    namespace = "com.piappstudio.digitaldiary"

    sourceSets["main"].manifest.srcFile("src/main/AndroidManifest.xml")

    defaultConfig {
        applicationId = "com.piappstudio.digitaldiary"
        minSdk = libs.versions.android.minSdk.get().toInt()
        targetSdk = libs.versions.android.targetSdk.get().toInt()
        versionCode = 66
        versionName = "2.0"
    }
    compileOptions {
        sourceCompatibility = JavaVersion.VERSION_17
        targetCompatibility = JavaVersion.VERSION_17
    }
    kotlin {
        jvmToolchain(17)
    }
    buildTypes {
        debug {
            proguardFiles(getDefaultProguardFile("proguard-android-optimize.txt"), "proguard-rules.pro")
        }
        release {
            isMinifyEnabled = true
            proguardFiles(getDefaultProguardFile("proguard-android-optimize.txt"), "proguard-rules.pro")
        }
    }
}
dependencies {
    implementation(project(":composeApp"))
}

Now, let’s compile and run the android project to make sure it is woring as expected before proceed further
Warning.

Supporting builtInKotlin when android.builtInKotlin=false

libs.versions.toml

/gradle/libs.versions.toml

[plugins]
jetbrainKotlinAndroid = { id = "org.jetbrains.kotlin.android", version.ref = "kotlin" }
androidKotlinMultiplatformLibrary = { id = "com.android.kotlin.multiplatform.library", version.ref = "agp" }

Update androidApp/build.gradle.kts

File: androidApp/build.gradle.kts

import org.jetbrains.kotlin.gradle.dsl.JvmTarget

plugins {
    alias(libs.plugins.jetbrainKotlinAndroid)
    alias(libs.plugins.androidApplication)
    alias(libs.plugins.composeMultiplatform)
    alias(libs.plugins.composeCompiler)

}

kotlin {
    target {
        compilerOptions {
            jvmTarget.set(JvmTarget.JVM_11)
        }
    }
    dependencies {

        implementation(project(":composeApp"))

        implementation(libs.compose.uiToolingPreview)
        implementation(libs.androidx.activity.compose)
   

    }

    android {
        compileSdk = libs.versions.android.compileSdk.get().toInt()
        namespace = "com.piappstudio.digitaldiary"

        defaultConfig {
            applicationId = "com.piappstudio.digitaldiary"
            minSdk = libs.versions.android.minSdk.get().toInt()
            targetSdk = libs.versions.android.targetSdk.get().toInt()
            versionCode = 66
            versionName = "2.0"
        }
        packaging {
            resources {
                excludes += "/META-INF/{AL2.0,LGPL2.1}"
            }
        }

        buildTypes {
            debug {
                proguardFiles(getDefaultProguardFile("proguard-android-optimize.txt"), "proguard-rules.pro")
            }
            release {
                isMinifyEnabled = true
                proguardFiles(getDefaultProguardFile("proguard-android-optimize.txt"), "proguard-rules.pro")
            }
        }
    }
}

Update project’s root build.gradle.kts

FileName: build.gradle.kts
+    alias(libs.plugins.jetbrainKotlinAndroid) apply false

Update composeApp/build.gradle.kts

Index: composeApp/build.gradle.kts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/composeApp/build.gradle.kts b/composeApp/build.gradle.kts
--- a/composeApp/build.gradle.kts	(revision 3f58f97d7de729adf13dd7c3086a06dc83ddb371)
+++ b/composeApp/build.gradle.kts	(date 1770341071189)
@@ -4,19 +4,14 @@
 
 plugins {
     alias(libs.plugins.kotlinMultiplatform)
-    alias(libs.plugins.androidLibrary)
+    alias(libs.plugins.androidKotlinMultiplatformLibrary)
     alias(libs.plugins.composeMultiplatform)
     alias(libs.plugins.composeCompiler)
     alias(libs.plugins.composeHotReload)
 }
 
 kotlin {
-    androidTarget {
-        compilerOptions {
-            jvmTarget.set(JvmTarget.JVM_11)
-        }
-    }
-    
+
     listOf(
         iosArm64(),
         iosSimulatorArm64()
@@ -65,19 +60,23 @@
             implementation(libs.kotlinx.coroutinesSwing)
         }
     }
-}
 
-android {
-    namespace = "com.piappstudio.digitaldiary.shared"
-    compileSdk = libs.versions.android.compileSdk.get().toInt()
-    compileOptions {
-        sourceCompatibility = JavaVersion.VERSION_11
-        targetCompatibility = JavaVersion.VERSION_11
+    androidLibrary {
+        namespace = "com.piappstudio.digitaldiary.shard"
+        compileSdk = libs.versions.android.compileSdk.get().toInt()
+        compilerOptions {
+            jvmTarget.set(JvmTarget.JVM_11)
+        }
+
+        androidResources {
+            enable = true
+        }
+
     }
 }
 
 dependencies {
-    debugImplementation(libs.compose.uiTooling)
+    androidRuntimeClasspath(libs.compose.uiTooling)
 }

Compile, and run the project and make sure everything works fine before touching the final nerves

Step 3 Removing Gradle 9.0.0 properties & Enabling newDSL & buildInKotlin

Now, make minor trick in androidApp/build.gradle.kts. Here, we are rolling back the changes we made for “org.jetbrains.kotlin.android” , which is not required when newDSL=true. Refer below .patch file for more details.

Subject: [PATCH] Refactor project structure and update build configurations

Index: androidApp/build.gradle.kts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/androidApp/build.gradle.kts b/androidApp/build.gradle.kts
--- a/androidApp/build.gradle.kts	(revision 70e52030549ff480ed9f0a36cf2860803bb5e8a0)
+++ b/androidApp/build.gradle.kts	(date 1770343677440)
@@ -3,7 +3,6 @@
 // https://github.com/kotlin-hands-on/get-started-with-cm/blob/main/gradle/libs.versions.toml
 //https://github.com/kotlin-hands-on/get-started-with-cm/tree/new-project-structure
 plugins {
-    alias(libs.plugins.jetbrainKotlinAndroid)
     alias(libs.plugins.androidApplication)
     alias(libs.plugins.composeMultiplatform)
     alias(libs.plugins.composeCompiler)
@@ -21,7 +20,7 @@
     }
     dependencies {
 
-        implementation(project(":composeApp"))
+        implementation(projects.composeApp)
 
         implementation(libs.compose.uiToolingPreview)
         implementation(libs.androidx.activity.compose)
Index: gradle/libs.versions.toml
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
--- a/gradle/libs.versions.toml	(revision 70e52030549ff480ed9f0a36cf2860803bb5e8a0)
+++ b/gradle/libs.versions.toml	(date 1770344246486)
@@ -51,7 +51,6 @@
 
 androidApplication = { id = "com.android.application", version.ref = "agp" }
 androidLibrary = { id = "com.android.library", version.ref = "agp" }
-jetbrainKotlinAndroid = { id = "org.jetbrains.kotlin.android", version.ref = "kotlin" }
 composeHotReload = { id = "org.jetbrains.compose.hot-reload", version.ref = "composeHotReload" }
 composeMultiplatform = { id = "org.jetbrains.compose", version.ref = "composeMultiplatform" }
 composeCompiler = { id = "org.jetbrains.kotlin.plugin.compose", version.ref = "kotlin" }
Index: build.gradle.kts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/build.gradle.kts b/build.gradle.kts
--- a/build.gradle.kts	(revision 70e52030549ff480ed9f0a36cf2860803bb5e8a0)
+++ b/build.gradle.kts	(date 1770344252515)
@@ -9,6 +9,4 @@
     alias(libs.plugins.kotlinMultiplatform) apply false
     alias(libs.plugins.androidKotlinMultiplatformLibrary) apply false
     alias(libs.plugins.androidLint) apply false
-    alias(libs.plugins.jetbrainKotlinAndroid) apply false
-
 }
\ No newline at end of file
Index: gradle.properties
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>ISO-8859-1
===================================================================
diff --git a/gradle.properties b/gradle.properties
--- a/gradle.properties	(revision 70e52030549ff480ed9f0a36cf2860803bb5e8a0)
+++ b/gradle.properties	(date 1770343722733)
@@ -9,14 +9,4 @@
 
 #Android
 android.nonTransitiveRClass=true
-android.builtInKotlin=false
-android.newDsl=false
\ No newline at end of file
+android.useAndroidX=true
\ No newline at end of file

That’s it. Now, you fully migrated to latest Android Gradle Plugin 9.0.0. 🔥🔥🔥

Reference:

https://kotlinlang.org/docs/multiplatform/multiplatform-project-agp-9-migration.html

Old Project Repo: https://github.com/kotlin-hands-on/get-started-with-cm/tree/main

New Project Repo: https://github.com/kotlin-hands-on/get-started-with-cm/tree/new-project-structure