fabric-language-kotlin

Fabric language module for Kotlin. Adds support for Kotlin exclusive entrypoints and bundles the Kotlin Stdlib as well as common kotlinx libraries.

Usage

Dependency

Add it as a dependency to your Gradle project:

dependencies {
    modImplementation("net.fabricmc:fabric-language-kotlin:1.13.7+kotlin.2.2.21")
}

Adapter

Use the kotlin adapter for your mod by setting the adapter property in the fabric.mod.json file. Remember to the add a dependency entry to your fabric.mod.json file:

{
    "schemaVersion":  1, 
    "entrypoints": {
        "main": [
            {
                "adapter": "kotlin",
                "value": "package.ClassName"
            }
        ]
    },
    "depends": {
        "fabric-language-kotlin": ">=1.13.7+kotlin.2.2.21"
    }
}

For more info reference the fabric.mod.json documentation.

Do not forget to set the schemaVersion to 1 or it will fall back to schema 0 and will not attempt to load entrypoints.

Entrypoint samples

Kind	Class reference	Function reference	Field reference
class	{ "adapter": "kotlin", "value": "mymod.MyMod" } package mymod class MyMod : ModInitializer { override fun onInitialize() { TODO() } }
object	{ "adapter": "kotlin", "value": "mymod.MyMod" } package mymod object MyMod : ModInitializer { override fun onInitialize() { TODO() } }	{ "adapter": "kotlin", "value": "mymod.MyMod::init" } package mymod object MyMod { fun init() { TODO() } }	{ "adapter": "kotlin", "value": "mymod.MyMod::initializer" } package mymod object MyMod { val initializer = ModInitializer { TODO() } }
companion object	{ "adapter": "kotlin", "value": "mymod.MyMod$Companion" } package mymod class MyMod { companion object : ModInitializer { override fun onInitialize() { TODO() } } }	{ "adapter": "kotlin", "value": "mymod.MyMod$Companion::init" } package mymod class MyMod { companion object { fun init() { TODO() } } }	{ "adapter": "kotlin", "value": "mymod.MyMod$Companion::initializer" } package mymod class MyMod { companion object { val initializer = ModInitializer { TODO() } } }
top level		{ "adapter": "kotlin", "value": "mymod.MyModKt::init" } File: src/main/kotlin/mymod/MyMod.kt package mymod fun init() { TODO() }

Companion objects can be used by appending $Companion to the class. Take care of processResources there, it might try to expand it, in that case escape it.

Bundled libraries

org.jetbrains.kotlin namespace:

• kotlin-stdlib 2.2.21 Docs, API docs, GitHub
• kotlin-reflect 2.2.21 Docs, API docs

org.jetbrains.kotlinx namespace:

• kotlinx-coroutines-core 1.10.2 Guide, API docs, GitHub
• kotlinx-coroutines-jdk8 1.10.2 API docs
• kotlinx-serialization-core 1.9.0 Guide, API docs, GitHub
• kotlinx-serialization-json 1.9.0 API docs
• kotlinx-serialization-cbor 1.9.0 API docs
• atomicfu 0.29.0 GitHub
• kotlinx-datetime 0.7.1 GitHub
• kotlinx-io-core 0.8.0 API docs, GitHub
• kotlinx-io-bytestring 0.8.0 API docs

Available Versions

https://maven.fabricmc.net/net/fabricmc/fabric-language-kotlin/

Updating README

• Update the readme in templates/README.template.md.
• Run ./gradlew processMDTemplates.