CurseForge · Minecraft mod
Chromosome Lib
Introduces genetic mechanisms for entities in Minecraft
Quick answer
Which Chromosome Lib release should I use?
Chromosome Lib chromosomelib-fabric-0.0.1+1.20.1.jar targets 1.20.1, 1.20 with Fabric. The project page does not say whether this file belongs on the client, dedicated server, or both. All 1 required mods have matching files.
Where it goes
Is Chromosome Lib required on the client, server, or both?
The project page does not say whether this file belongs on the client, dedicated server, or both.
The source does not explicitly classify this release as client-only or server-only.
What else does Chromosome Lib chromosomelib-fabric-0.0.1+1.20.1.jar need?
chromosomelib-fabric-0.0.1+1.20.1.jar. Change the file and its required mods may change too.
Install Fabric API first. We found matching files for this game-version and loader setup.
We only count dependency files that match this setup. A file for another loader does not fill the gap.
Before you install it
Add Chromosome Lib without breaking your instance.
Built for Chromosome Lib chromosomelib-fabric-0.0.1+1.20.1.jar. Pick another file and the loader, install side or required mods may change.
- 01
Stick to this file
Use chromosomelib-fabric-0.0.1+1.20.1.jar. It targets 1.20.1, 1.20 with Fabric; another release may have different loader, side or dependency requirements.
- 02
Bring the mods it needs
Install Fabric API first. We found matching files for this game-version and loader setup.
- 03
Put it on the correct side
The project page does not say whether this file belongs on the client, dedicated server, or both.
- 04
Pick the file you checked
Use the “Get this file” button beside chromosomelib-fabric-0.0.1+1.20.1.jar. It opens that exact file at the source.
About this project
What does Chromosome Lib add?
Abstract
This is a library mod that introduces chromosome-based genetic mechanisms for entities, such as villagers, sheeps, cows, in Minecraft. It does not provide any actual functionality on its own, but serves as a powerful and compatible library that integrates traits and genetic systems for dependents.
For developers to create dependents of this mod, please read the following sections.
Architecture

Core capabilities
- Multi-loader support: Works seamlessly on both Fabric and (Neo)Forge.
- Five custom registries for chromosomes, gene loci, genes, traits, and trait types.
- Extensible trait system allowing developers to define custom observable characteristics.
Registration
Chromosomes, Gene Loci, Genes, Traits and Trait Types can be registered through this mod.
We also provide some built-in chromosomes for vanilla animals such as sheep, cows, polar bears, humans, to prevent conflicts between different mods by registering different chromosomes to the same entity.
Inheritance
Automatic chromosome inheritance, including gene recombination and mutation, default gene selectors, are reusable to any mobs, which is managed by chromosome lib. So there's no need for developers to understand how it's implemented - they can code in a really easy way.
Debug Commands
We also provide several commands for players to show and modify genes of entities easily, and reassign traits of them based on their genes.
Use Cases
This library is perfect for:
- Wildlife and animal husbandry mods wanting realistic breeding systems.
- RPG mods requiring hereditary traits and characteristics.
- Educational mods teaching genetics and biology concepts.
- Any mod that needs sophisticated inheritance mechanics.
Get Started
Add Viola Siemens's Maven to repository in your build.gradle.
repositories {
maven {
name = 'Maven from Viola Siemens'
url = "https://viola-siemens.github.io/pages/maven/"
}
}
Declare Chromosome Lib as your dependency.
Forge:
implementation fg.deobf("com.hexagram2021:chromosomelib-forge:${chromosomelib_version}")
Fabric:
modImplementation group: 'com.hexagram2021', name: 'chromosomelib-fabric', version: chromosomelib_version
NeoForge:
implementation group: 'com.hexagram2021', name: 'chromosomelib-neoforge', version: chromosomelib_version
MultiLoader:
// ^common/build\.gradle$
modImplementation group: 'com.hexagram2021', name: 'chromosomelib-common', version: chromosomelib_version
// ^forge/build\.gradle$
modImplementation group: 'com.hexagram2021', name: 'chromosomelib-forge', version: chromosomelib_version
// ^fabric/build\.gradle$
modImplementation group: 'com.hexagram2021', name: 'chromosomelib-fabric', version: chromosomelib_version
// ^neoforge/build\.gradle$
modImplementation group: 'com.hexagram2021', name: 'chromosomelib-neoforge', version: chromosomelib_version
Example Mods
Project description from CurseForge.
Pick your setup
Chromosome Lib by Minecraft version and loader
Choose the version and loader you play, then open the matching release.
1.20.1
2 loader builds1.20
2 loader buildsCheck the dependencies, then try the file in a copied instance before changing a world you care about.
Recent files
Chromosome Lib versions and loaders
chromosomelib-fabric-0.0.1+1.20.1.jar
17 Nov 2025
chromosomelib-forge-0.0.1+1.20.1.jar
17 Nov 2025
Looking for an older file? The official CurseForge project page is in Resources.