Kotlin for Forge

Used to make mods with the Kotlin programming language. Works by shading the Kotlin libraries, providing KotlinLanguageProvider to load @Mod object declarations, providing AutoKotlinEventBusSubscriber to load @EventBusSubscriber declarations, and providing useful utility functions and constants.

As of Kotlin for Forge 1.8.0, this provides Kotlin 1.4.21, Kotlin coroutines 1.4.2, Kotlin JSON serialization 1.0.1, and Jetbrains annotations 20.1.0.

If you're not a mod developer, this is a dependency mod.

Unlike Kottle, this library (as of 1.2.0) provides its own implementation of IEventBus that supports IEventBus#addListener and IEventBus#addGenericListener with function references.

Information for how to implement can be found here.
You do not have to use the language loader or any of the features Kotlin for Forge provides, you can just use it for the bundled Kotlin libraries.

If you'd like to ask for help or suggest something, feel free to do so on the Kotlin for Forge discord server.

ABOUT THIS LISTING

This page describes Kotlin for Forge by thedarkcolour. The description and screenshots are the author's own, imported from their listing on Modrinth on 31 August 2026: https://modrinth.com/mod/kotlin-for-forge

Mythiq.net hosts no files for it. The download button goes straight to the release file on cdn.modrinth.com, so you are downloading from the author's own host, not from a copy of ours.

The download count, rating and comments on this page start at zero and count Mythiq.net only. The source's own figures are not copied here — they measure a different site, and a number that cannot be checked against our own ledger is not worth printing.

MOD LOADER

This release is built for Forge and Neoforge. A mod built for one loader will not load under another — Fabric mods do not run on Forge, and vice versa.

GAME VERSION

Built for Minecraft 1.21.8, 1.21.7, 1.21.6, 1.21.5, 1.21.4, 1.21.3. Minecraft mods are tied to an exact version: a 1.21.4 build will refuse to load on 1.21.5.

THIS IS A LIBRARY

On its own it adds nothing you can see. It is here because other mods require it, and installing it is usually something another mod asked you to do.

DEPENDENCIES

Check the author's listing for required libraries before you start the game — a missing dependency shows up as a crash on launch, not as a warning.

1. Install Forge for the Minecraft version you play, if you have not already.

2. Download the .jar with the button on this page. Do not unzip it — a mod jar is installed as it is.

3. Put it in your mods folder:

Windows — %APPDATA%\.minecraft\mods

macOS — ~/Library/Application Support/minecraft/mods

Linux — ~/.minecraft/mods

4. Launch the game with the Forge profile selected.

ON A SERVER

Anything that changes world generation or gameplay has to be installed on the server as well as on every client. Client-side visual and interface mods do not.

UPDATING

Replace the old .jar rather than adding the new one beside it. Two versions of the same mod in the folder is a crash on launch.