Kotlin can also be used as a scripting language, which is safer, concise, and fun to write than bash or python. GitHub has recently enabled Kotlin on Github Action runners, which enables us to use Kotlin Script on GitHub Action out of the box. But using compiler plugins (eg: kotlinx-serialization) is not straightforward with Kotlin script and requires a bit of fiddling. kts-exec is a composite GitHub Action to execute the Kotlin Script (on mac/linux /windows) with a given kotlin compiler plugin and dependency caching.

Required The Kotlin script to execute. Default script name is script.main.kts.

Optional Kotlin compiler plugin to use. Currently, supported values are

• kotlinx-serialization (Default)
• allopen
• noarg
• lombok
• sam-with-receiver
• kotlin-imports-dumper

Optional Enable kotlin script dependencies caching. It is enabled (true) by default.

Local path to the kotlin compiler-plugin. You may also access the path via ${{ env.PLUGIN_PATH }}.

The kotlin installation path. You may also access the path via ${{ env.KOTLIN_ROOT }}.

Say, you want to execute the kotlin script with a Serializable data class for JSON processing

@file:DependsOn("org.jetbrains.kotlinx:kotlinx-serialization-json:1.6.2")

import kotlinx.serialization.*
import kotlinx.serialization.json.*

@Serializable
data class Lang(val name: String, val version: String)

val arg = args.firstOrNull() ?: "Kotlin"
println("Hello $arg!")

val serialized = Json.encodeToString(Lang("Kotlin", KotlinVersion.CURRENT.toString()))
println(serialized)

Add the kt-exec to your workflow and run your kotlin script.

jobs:
  build:
    runs-on: ubuntu-lastest
    steps:
      - name: Check out repository
        uses: actions/checkout@v4

      - name: Run Kotlin Script
        uses: sureshg/[email protected]
        with:
          script: "script.main.kts"