Compile-time Aspect-Oriented Programming for Kotlin Multiplatform.

AspectK is a Kotlin compiler plugin that injects advice code at compile time via K2 IR transformation — no runtime reflection, no proxies, zero overhead. Declare an @Aspect, annotate your advice with @Before, and AspectK weaves the call directly into the intercepted functions during compilation.

// build.gradle.kts
plugins {
    id("io.github.mole-labs.aspectk") version "LATEST_VERSION"
}

For Kotlin Multiplatform:

plugins {
    kotlin("multiplatform")
    id("io.github.mole-labs.aspectk") version "LATEST_VERSION"
}

@Target(AnnotationTarget.FUNCTION)
@Retention(AnnotationRetention.BINARY)
annotation class Logged

import io.github.molelabs.aspectk.runtime.Aspect
import io.github.molelabs.aspectk.runtime.Before
import io.github.molelabs.aspectk.runtime.JoinPoint

@Aspect
object LoggingAspect {
    @Before(target = [Logged::class])
    fun log(joinPoint: JoinPoint) {
        println("→ ${joinPoint.signature.methodName}(${joinPoint.args.joinToString()})")
    }
}

@Logged
fun processOrder(orderId: String, amount: Double) {
    // AspectK injects LoggingAspect.log() here at compile time
}

AspectK works with the full range of Kotlin function kinds — including those that other AOP solutions struggle with. Because advice is injected during the IR transformation phase, before platform-specific lowering, AspectK intercepts functions exactly as Kotlin defines them:

• Class member functions
• Top-level functions
• Extension functions
• suspend functions — interception happens before coroutine lowering, so the advice sees the function in its original, unsuspended form
• inline functions — intercepted at the call site before the inliner runs
• Property getters and setters
• expect/actual functions across all platforms

JVM · Android · JS (IR) · WASM/JS · macOS (arm64, x64) · iOS (arm64, sim, x64) · Linux (arm64, x64) · Windows (x64) · watchOS · tvOS · Android Native

Full documentation: https://mole-labs.github.io/aspectk/

• Installation
• Quick Start
• Core Concepts
• API Reference

Copyright 2026 Mole Labs

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    https://www.apache.org/licenses/LICENSE-2.0