KSP with Kotlin Multiplatform

Here you'll learn how to use Kotlin Symbol Processing (KSP) in a Kotlin Multiplatform project. For a quick start, see an example of a multiplatform project with several targets using KSP in the source repository. The processor in this example generates a Foo class used by the project.

Add KSP to a multiplatform project

In the build.gradle.kts file of the client module (the module that uses the processor), add the appropriate KSP processor dependency for each target that requires symbol processing:

dependencies {
  add("ksp<Target>", <processor>)
}

<Target> is one of the targets used in your multiplatform project.
For a full list of targets, see Multiplatform Gradle DSL reference and Kotlin/Native supported targets.
<processor> is a Gradle project path. It can be:
- a specific directory in your project that contains the logic for your symbol processor:
  add("kspJvm", project(":local-processor"))
- an external processor such as Room:
  add("kspJvm", "androidx.room:room-compiler:2.6.1")

Use mutiple processors in a single target

You can add more than one processor to a target:

add("kspAndroid", project(":test-processor"))
add("kspAndroid", "androidx.room:room-compiler:2.6.1")

add('kspAndroid', project(':test-processor'))
add('kspAndroid', 'androidx.room:room-compiler:2.6.1')

Use the same processor in multiple targets

You can add the same processor to more than one target:

add("kspIosX64", project(":test-processor"))
add("kspIosArm64", project(":test-processor"))
add("kspIosSimulatorArm64", project(":test-processor"))

add('kspIosX64', project(':test-processor'))
add('kspIosArm64', project(':test-processor'))
add('kspIosSimulatorArm64', project(':test-processor'))

If you have many iOS targets, you can avoid repetition by looping:

kotlin.targets.filter { it.name.startsWith("ios") }.forEach { target ->
    add(
        "ksp${target.name.replaceFirstChar { it.uppercaseChar() }}",
        project(":test-processor")
    )
}

kotlin.targets.filter { it.name.startsWith("ios") }.forEach { target ->
    add(
        "ksp${target.name.replaceFirstChar { it.uppercaseChar() }}",
        project(":test-processor")
    )
}

Configure KSP for test compilations

To run KSP during test compilation, add the processor to the corresponding test configurations:

add("kspJvmTest", project(":test-processor"))
add("kspJsTest", project(":test-processor"))
add("kspIosX64Test", project(":test-processor"))

add('kspJvmTest', project(':test-processor'))
add('kspJsTest', project(':test-processor'))
add('kspIosX64Test', project(':test-processor'))

For Android host and device tests, KSP derives configuration names from the corresponding source set names:

add("kspAndroidHostTest", project(":test-processor"))
add("kspAndroidDeviceTest", project(":test-processor"))

add('kspAndroidHostTest', project(':test-processor'))
add('kspAndroidDeviceTest', project(':test-processor'))

Find KSP configuration names

KSP derives configuration names from the Kotlin Multiplatform source sets. To view the complete list of KSP configurations for a module, run:

./gradlew :<your-module-name>:dependencies | grep ksp

Look for the configuration names that correspond to your target source sets.

Compilation and processing

In a multiplatform project, Kotlin creates a separate compilation for each target and source set, such as main andtest. For each Kotlin compilation task with one or more configured KSP processors, KSP creates a corresponding symbol processing task.

The example project defines six targets. Each target has main and test compilations, resulting in the following compilation and symbol processing tasks:

JVM: jvmMain and jvmTest
JS: jsMain and jsTest
LinuxX64: linuxX64Main and linuxX64Test
AndroidNativeX64: androidNativeX64Main and androidNativeX64Test
AndroidNativeArm64: androidNativeArm64Main and androidNativeArm64Test
MingwX64: mingwX64Main and mingwX64Test

In the example's workload/build.gradle.kts file, KSP dependencies are declared for the following configurations:

kspJvm and kspJvmTest
kspJs and kspJsTest
kspAndroidNativeX64 and kspAndroidNativeX64Test
kspAndroidNativeArm64 and kspAndroidNativeArm64Test
kspLinuxX64
kspMingwX64

KSP creates a symbol processing task for each configuration where a KSP dependency is declared. In this example, the project creates at least 12 Kotlin compilation tasks and 10 symbol processing tasks. The remaining compilations don't have corresponding KSP tasks because KSP isn't configured for them.

23 July 2026