
Chromosome Lib
I don't know my version or loader
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
- Edition: Minecraft Java
- File type: .jar
- Minecraft versions listed: 1.20, 1.20.1
- How to install: Install the matching mod loader (Forge, Fabric or NeoForge) for your Minecraft version. → Download the .jar. → Put it in the .minecraft/mods folder and launch that loader profile.
- Where to get it: Opens on Modrinth — not every file is mirrored on our own servers.
Install steps are the general flow for this file type — How to install Minecraft Java mods & modpacks walks through it step by step.
- Ships as chromosomelib-fabric-0.0.1+1.20.1.jar — drop this file into the mods folder
- Download size: 164 KB
- Download link checked 7 Sept 2026 — working
These come from our own check of the pack file, not from the source page.