Declaring compatibility with K2

The Kotlin IntelliJ plugin assumes that a dependent third-party plugin does not support K2 Kotlin out of the box. Such incompatible plugins will not be loaded if the K2 mode is currently enabled.

Once a plugin has been migrated to the Analysis API, a setting should be added to its plugin.xml to declare its compatibility with the K2 mode. Even if the plugin does not use any of the old K1 analysis functions and no migration to the Analysis API is needed, compatibility with the K2 Kotlin plugin should be declared explicitly nonetheless.

Starting from IntelliJ 2024.2.1 (Preview), the following setting in the plugin.xml can be used to declare compatibility with the K2 mode:

<extensions defaultExtensionNs="org.jetbrains.kotlin">
    <supportsKotlinPluginMode supportsK2="true" />
</extensions>

It is also possible to declare compatibility with only the K2 mode:

<extensions defaultExtensionNs="org.jetbrains.kotlin">
    <supportsKotlinPluginMode supportsK1="false" supportsK2="true" />
</extensions>

Currently, the default setting for supportsK1 is true and for supportsK2 is false.

To test it locally when using the IntelliJ Platform Gradle Plugin, add a dependency on the IntelliJ IDEA Community 2024.2.1 (intellijIdeaCommunity("2024.2.1")) or higher.

A number of third-party plugins may already be enabled in the K2 mode without a supportsK2 declaration. The IntelliJ Kotlin plugin keeps an internal list of plugins which are known to be compatible with the K2 mode as they do not use Kotlin analysis. The authors of these plugins should not be surprised if their plugin already works in the K2 mode. However, it's still advised to check and declare K2 support explicitly as this list is not future-proof and could potentially contain unsafe plugins due to some circumstances.

Last modified: 30 September 2024