Fabric mod dependency guide

Fabric Language Kotlin Mod for clean Kotlin-powered Fabric setups

Understand what the library does, how dependency matching works, which Minecraft versions are commonly listed, and why the source ZIP differs from a compiled mod JAR.

Download Fabric Language Kotlin Mod How It Works
Kotlin entrypoints Client & server library Fabric Loader ecosystem
Original dashboard illustration for Fabric Language Kotlin Mod
Runtime dependency
Source-aware setup
Fabric Language Kotlin runtime and libraries illustration
What is it?

A language layer for Kotlin-based Fabric mods

Fabric Language Kotlin enables Kotlin-specific Fabric entrypoints and bundles Kotlin runtime libraries that dependent mods can share. It is infrastructure, not a gameplay content pack.

K

Kotlin entrypoint support

Lets mod metadata use the Kotlin adapter for Kotlin classes and functions.

Σ

Bundled runtime libraries

Includes Kotlin stdlib, reflection, coroutines, serialization, datetime, IO, and related libraries in current releases.

Features

Designed as shared runtime infrastructure

The module reduces repeated Kotlin runtime packaging across Fabric mods while giving developers a standard language adapter.

01 / LANGUAGE

Kotlin adapter

Supports Kotlin-specific entrypoints declared through Fabric mod metadata.

02 / RUNTIME

Stdlib included

Bundles the Kotlin standard library and reflection support used by many Kotlin mods.

03 / LIBRARIES

Common kotlinx packages

Current builds bundle commonly used coroutines, serialization, datetime and IO libraries.

04 / ENVIRONMENT

Client and server

Published project metadata supports both environments, subject to the needs of each dependent mod.

How it works

Dependency first, content second

A Kotlin-based Fabric mod declares Fabric Language Kotlin as a dependency. Fabric Loader checks the installed library version before the dependent mod starts.

1

Loader profile

Launch the correct Minecraft version with Fabric Loader.

2

Version match

Choose a compiled Fabric Language Kotlin build accepted by the dependent mod.

3

Runtime ready

Fabric loads the shared Kotlin language layer before dependent mods initialize.

Compatibility

Broad Minecraft coverage, but dependency ranges still matter

Official distribution listings include older Java Edition lines through 1.20.x and 1.21.x, as well as newer 26.1.x and 26.2 releases. The project itself is designed around Fabric Loader availability.

Always follow the version range requested by the mod that depends on Fabric Language Kotlin. A newer library is not automatically the correct choice for an older curated pack.
1.20.x Common established Fabric packs
1.21.x Modern Fabric modpacks
26.1.x Newer version line
26.2 Listed in current compatibility data
Use cases

Where the library fits

You normally install this library because another mod needs it, not because you expect direct gameplay features.

Kotlin-based gameplay mods

Provides the shared language runtime required by mods implemented with Kotlin.

Client utilities

Supports client-side mods that use Kotlin entrypoints or bundled Kotlin libraries.

Fabric servers

Can be part of server-side dependency stacks when server mods require it.

Download

Download Fabric Language Kotlin Mod

The provided project link downloads the current GitHub master branch source ZIP .

Format: ZIP source Host: GitHub Project: FabricMC
Download Fabric Language Kotlin Mod
Important: this source ZIP is not a compiled mod JAR. Players should use a compatible published JAR required by their modpack; developers can use the source archive for inspection or building.
Source download dashboard illustration
Safety notice

Keep source, release files, and dependencies clear

Most setup problems come from wrong file types or mismatched versions rather than from the language library itself.

Use original distribution channels

Avoid repacked installers or renamed archives. Verify the project name and version metadata before adding files to a modpack.

Back up a working instance

Before changing loader or library versions, keep a backup or exported profile so you can roll back cleanly.

Installation / setup

Three checks before launch

For gameplay use, install the compiled release JAR that meets your dependent mod’s version requirement.

1

Confirm Fabric Loader

Use the intended Minecraft and Fabric Loader profile.

2

Match the required version

Read the dependent mod metadata or loader error for the accepted Fabric Language Kotlin range.

3

Add the compiled JAR

Place it in the active instance mods folder and keep only one compatible copy.

Pros and cons

Useful infrastructure with version responsibilities

Advantages

  • Standard Kotlin language adapter for Fabric mods.
  • Shared Kotlin runtime reduces duplicated library packaging.
  • Supports both client and server environments.
  • Maintained as part of the FabricMC ecosystem.

Considerations

  • Does not add gameplay content by itself.
  • Must satisfy dependent mod version requirements.
  • A source ZIP is not a drop-in runtime JAR.
  • Updating one library inside an old pack can expose conflicts.
Release information

Current release reference

1.14.1+kotlin.2.4.20

GitHub release listings showed this as the latest release when this site was prepared on September 13, 2026. Check your dependent mod’s accepted range before updating.

Project facts

Project type
Library
Platform
Fabric
License
Apache-2.0
Environment
Client / Server
Troubleshooting

Start with the first dependency error

Fabric Loader messages usually tell you whether the library is missing, duplicated, or outside the required version range.

Missing library

Confirm a compiled JAR is in the active mods folder and that you launched the expected profile.

Wrong version

Match the version range requested by the dependent mod instead of selecting by newest date alone.

Duplicate files

Remove extra copies and keep one compatible Fabric Language Kotlin JAR.

Guides preview

Version and setup guides

View Guide Library
Fabric Language Kotlin download guide

Download guide

Source ZIP vs compiled JAR, safe setup, and version selection.

Read guide →
Fabric Language Kotlin 1.21.4 guide

Minecraft 1.21.4 setup

Loader, mods folder, client/server use, and dependency errors.

Read guide →
Fabric Language Kotlin troubleshooting guide

Troubleshooting

Fix missing dependencies, version conflicts, and server startup issues.

Read guide →
FAQ

Fabric Language Kotlin questions

Exactly 20 practical answers split into setup and troubleshooting categories.

Getting Started

It is a Fabric language module that enables Kotlin-specific entrypoints and bundles the Kotlin standard library plus several common kotlinx libraries for Fabric mods.
No. It is a dependency and language-support library. It does not add game content by itself.
You need it when another Fabric mod declares fabric-language-kotlin as a required dependency, usually because that mod is written in Kotlin or uses Kotlin entrypoints.
Yes. Fabric Language Kotlin is built for the Fabric ecosystem and expects Fabric Loader to be available.
Official distribution information lists both client-side and server-side support. Whether you need it on each side depends on the mod that requires it.
For a normal Fabric instance, place the compatible compiled JAR in that instance’s mods folder. Do not extract the JAR.
No. The provided download link on this site is the repository source ZIP. It is intended for source access and building, not direct placement in the Minecraft mods folder.
Official listings include the 1.21.x family. Always choose a library build that satisfies the dependent mod’s declared version requirement.
Published compatibility includes 1.20.x. Match the exact modpack, Fabric Loader, and dependent mod requirements rather than selecting by Minecraft version alone.
It lets Fabric mod metadata point entrypoints at Kotlin classes or functions using the Kotlin language adapter.

Versions & Troubleshooting

A mod in your instance requires Fabric Language Kotlin, but Fabric Loader cannot find a compatible installed JAR.
Read the required version range in the loader message, then use a Fabric Language Kotlin build that satisfies that range or update the dependent mod.
No. Duplicate versions can create conflicts. Keep one compatible version that satisfies all dependent mods in the instance.
Another dependency can still be missing, or the installed version may be outside the required range. Read the first actionable Fabric Loader error in the log.
No. They are different dependencies. A mod may require Fabric API, Fabric Language Kotlin, both, or neither.
No. YACL is a separate configuration library. A Kotlin-based mod can require Fabric Language Kotlin and YACL at the same time.
At the time this site was prepared in September 2026, the current GitHub release list showed Fabric Language Kotlin 1.14.1+kotlin.2.4.20.
You can, but it is safer to check dependent mods first. Curated packs may rely on a tested combination of loader and library versions.
Fabric Loader expects compiled mod JARs. A GitHub source ZIP contains project source and build files, not the runtime artifact the loader scans as a mod.
Check the server log, verify the server uses the expected Fabric Loader profile, compare required library versions, and confirm the compiled JAR is in the server mods folder.