Fabric Language Kotlin Mod, the block every Kotlin mod stands on

It is a library mod for Minecraft: Java Edition on Fabric Loader. It lets Fabric load mods written in Kotlin and supplies the Kotlin runtime libraries they share. It adds no gameplay content of its own.

That mod was written in Kotlin, or uses Kotlin libraries, and cannot start without the shared runtime. Fabric Loader checks declared dependencies before launch and stops with a message naming the missing mod ID.

No. The button downloads the master branch source archive of the FabricMC/fabric-language-kotlin GitHub repository. It is source code in a .zip file. Players who need a loadable mod should use a built .jar release, commonly found on mod platforms such as Modrinth and CurseForge.

Place the built .jar in the mods folder of the Fabric game profile or launcher instance you play with. On a default Windows install that is %appdata%\.minecraft\mods. Keep only one copy of the library.

No. Fabric Loader reads .jar files directly. Extracting the jar, or placing the source .zip in the mods folder, means the loader will not recognise it as a mod.

Fabric Language Kotlin and Fabric API are separate libraries. Many mods require both, some require only one. Check each mod's dependency list and install everything it marks as required.

No. There are no settings to change and no in-game menu. Once the jar is in the mods folder and the game starts, mods that depend on it can load.

If a Kotlin-based mod runs on the server, yes. Install a compatible build in the server's own mods folder. Client and server should run versions that satisfy the same mods.

Replace the old jar with the newer build, rather than adding the new one beside it. Two copies trigger a duplicate mod error. Launchers with mod management can usually update it for you.

Yes, if you are comfortable with development tools. The project uses Gradle and includes the Gradle wrapper, so you can run the build task with a suitable JDK installed. The master branch may be ahead of the latest published release.

It works with Minecraft: Java Edition versions that Fabric Loader supports and for which builds are published. Because it is a language library, it tends to be less tied to one game version than content mods, but you should still pick a build that the release page lists for your version and that satisfies your mods.

Players commonly run Kotlin-based Fabric mods on both versions. Use the Fabric Loader profile for your version, run it on Java 17, and pick a library build that meets the minimum version your mods request.

Treat each as its own target. Filter the library's release listings by your exact game version and the Fabric loader, confirm your Java runtime matches the game's requirement, and check your mods' stated minimum library version.

No. It is a Fabric mod. Forge and NeoForge use different loaders, and Kotlin mods for those loaders rely on separate Kotlin libraries made for them.

No. Bedrock Edition, including the mobile version often called MCPE, does not run Java mods or Fabric Loader. This library is for Minecraft: Java Edition only.

Built releases are published on mod platforms including Modrinth and CurseForge. Check that the listing is published by FabricMC and filter by your game version and the Fabric loader.

No. Yet Another Config Lib is a separate library that mods use to build settings screens. Some mods require both libraries, but installing one does not replace the other.

No. It adds no content and is not a performance mod. It only provides what Kotlin-based mods need in order to run.

No. Fabric Loader treats two copies as duplicates and refuses to start. Keep the newest build that satisfies all your mods.

Add net.fabricmc:fabric-language-kotlin as a Gradle dependency, use the kotlin adapter for your entrypoints in fabric.mod.json, and list fabric-language-kotlin under depends so players see a clear message if it is missing.