Instructions for other versions: 1.20.6 | 1.19.2 | 1.14-1.16.5 | 1.17-1.17.1

Makes Kotlin Forge-friendly by doing the following:

• Provides Kotlin stdlib, reflection, JSON serialization, and coroutines libraries.
• Provides KotlinLanguageProvider to allow usage of object declarations as @Mod targets.
• Provides AutoKotlinEventBusSubscriber to allow usage of object declarations as @Mod.EventBusSubscriber targets.
• Provides useful utility functions and constants

A 1.19.3 (works for 1.19.4 too) example mod is provided here: 1.19.3 KotlinModdingSkeleton repository
A 1.20 example mod is provided here: 1.20 KotlinModdingSkeleton repository
A 1.20.6 example mod is provided here: 1.20.6 KotlinModdingSkeleton repository

If you aren't sure where to start, make a fork of the KotlinModdingSkeleton repository (replace BRANCH with your version)

git clone --branch BRANCH https://github.com/thedarkcolour/KotlinModdingSkeleton.git

To implement in an existing project, merge the following into your build script:

plugins {    
    // Adds the Kotlin Gradle plugin
    id 'org.jetbrains.kotlin.jvm' version '1.9.22'
    // OPTIONAL Kotlin Serialization plugin
    id 'org.jetbrains.kotlin.plugin.serialization' version '1.9.22'
}

repositories {
    // Add KFF Maven repository
    maven {
        name = 'Kotlin for Forge'
        url = 'https://thedarkcolour.github.io/KotlinForForge/'
    }
}

dependencies {
    // Adds KFF as dependency and Kotlin libs (use the variant matching your mod loader)
    // FORGE
    implementation 'thedarkcolour:kotlinforforge:4.10.0'
    // NEOFORGE
    implementation 'thedarkcolour:kotlinforforge-neoforge:4.10.0'
}

plugins {
    // Adds the Kotlin Gradle plugin
    kotlin("jvm") version "1.9.22"
    // OPTIONAL Kotlin Serialization plugin
    kotlin("plugin.serialization") version "1.9.22"
}

repositories {
    // Add KFF Maven repository
    maven {
        name = "Kotlin for Forge"
        setUrl("https://thedarkcolour.github.io/KotlinForForge/")
    }
}

dependencies {
    // Adds KFF as dependency and Kotlin libs (use the variant matching your mod loader)
    // FORGE
    implementation("thedarkcolour:kotlinforforge:4.10.0")
    // NEOFORGE
    implementation("thedarkcolour:kotlinforforge-neoforge:4.10.0")
}

Then, change the following to your mods.toml file:

modLoader="kotlinforforge"
# Change this if you require a certain version of KotlinForForge
loaderVersion="[4.10,)"

Use thedarkcolour.kotlinforforge.forge.MOD_CONTEXT
instead of net.minecraftforge.fml.javafmlmod.FMLJavaModLoadingContext