What state management framework should I use with Jewel? (Compose)

IntelliJ Platform
1

I’ve tried using both Molecule and Koin for state management, but I’m running into class loader errors with both of them. Does anyone know how to fix this?

java.lang.ClassCastException: class androidx.compose.runtime.ComposerImpl cannot be cast to class androidx.compose.runtime.Composer (androidx.compose.runtime.ComposerImpl is in unnamed module of loader com.intellij.ide.plugins.cl.PluginClassLoader @5d06915d; androidx.compose.runtime.Composer is in unnamed module of loader com.intellij.ide.plugins.cl.PluginClassLoader @4adf6740)
	at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jb.kt:33)
	at org.jetbrains.jewel.bridge.ToolWindowExtensionsKt.addComposeTab$lambda$0(ToolWindowExtensions.kt:26)

Here’s my configuration:

dependencies {

    implementation("ai.koog:koog-agents:0.3.0"){
        exclude(group = "org.jetbrains.compose")
        exclude(group = "androidx.compose")
        exclude(group = "androidx.compose.runtime")
        exclude(group = "androidx.compose.ui")
        exclude(group = "androidx.compose.foundation")
        exclude(group = "androidx.compose.material")
    }
    testImplementation("junit:junit:4.13.2")
    testImplementation("org.jetbrains.kotlinx:kotlinx-coroutines-test:1.10.2")
    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.10.2")
    implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.9.0")
    implementation("app.cash.molecule:molecule-runtime:${molecule_version}"){
        exclude(group = "org.jetbrains.compose.material")
    }

    intellijPlatform {
        create("IC", "2025.2")
        testFramework(TestFrameworkType.Platform)
        bundledModule("intellij.platform.jewel.foundation")
        bundledModule("intellij.platform.jewel.ui")
        bundledModule("intellij.platform.jewel.ideLafBridge")
        bundledModule("intellij.platform.jewel.markdown.core")
        bundledModule("intellij.platform.jewel.markdown.ideLafBridgeStyling")
        bundledModule("intellij.libraries.compose.foundation.desktop")
        bundledModule("intellij.libraries.skiko")
    }
}
3

Hey, most probably

jetbrains.compose.runtime.desktop

loaded somewhere twice and you have to exclude it as well.

4

Please take a look on our examples of plugin development with Compose intellij-platform-compose-plugin-template/src/main/kotlin/org/jetbrains/plugins/template/weatherApp/ui/WeatherAppViewModel.kt at main · JetBrains/intellij-platform-compose-plugin-template · GitHub . This approach doesn’t require additional libraries.

1 Like
5

I’m not intimately familiar with the dependencies tree used of Molecule and Koin, but you very much want to make sure they are not bringing in Compose as a transitive dependency. Only the one from the platform should end up on the classpath if you want to avoid classloading issues.

The same goes for coroutines, and possibly kotlinx-serialization — I think they should already be on the classpath from the platform, or at least can be brought in from it.

6

Thank you, this example is helpful to me.