Intro

• FAQ
• Features
• Global

FAQ

What does this mod do?

This mod lets you create scripts in JavaScript language to manage your server, add new blocks and items, change recipes, add custom handlers for quest mods and more!

How to use it?

Run the game with mod installed once. It should generate kubejs folder in your minecraft directory with example scripts and README.txt. Read that!

Here's a video tutorial for 1.19.2:

I don't know JavaScript

There's examples and pre-made scripts here. And you can always ask in discord support channel for help with scripts, but be specific.

Can I reload scripts?

Yes, use /reload to reload server_scripts/, F3 + T to reload client_scripts/ and /kubejs reload startup_scripts to reload startup_scripts/. If you don't care about reloading recipes but are testing some world interaction event, you can run /kubejs reload server_scripts. Note: Not everything is reloadable. Some things require you to restart game, some only world, some work on fly. Reloading startup scripts is not recommended, but if you only have event listeners, it shouldn't be a problem.

What mod recipes does it support / is mod X supported?

If the mod uses datapack recipes, then it's supported by default. Some more complicated mods require addon mods, but in theory, still would work with datapack recipes. See Recipes and Addons sections for more info.

What features does this mod have?

See list of all Features.

How does this mod work?

It uses a fork of Rhino, a JavaScript engine by Mozilla to convert JS code to Java classes at runtime. KubeJS wraps minecraft classes and adds utilities to simplify that a lot and remove need for mappings. Architectury lets nearly the same source code be compiled for both Forge and Fabric making porting extremely easy.

Ok, but what if it.. doesn't work?

You can report issues here.

I have more questions/suggestions!

If wiki didn't have the answer for what you were looking for, you can join the Discord server and ask for help on #support channel!

Website: https://kubejs.com/

Source and issue tracker: https://github.com/KubeJS-Mods/KubeJS

Download: https://www.curseforge.com/minecraft/mc-mods/kubejs

Anything below 1.18 is no longer supported!

Features

Here's a list of all documented (and sometimes undocumented) features that I can remember:

• [Full list of events]
• Editing Recipes
• Editing Tags
• Adding New Items
• Adding New Blocks
  
• Default Options
• Changing Window Title and Icon
• Changing Mod Display Names
• Loading Assets and Data
• Modify Items
• Modify Blocks
• Adding Fluids
• Worldgen
• Chat event
• Block placement event
• Item right-click event
• And a bunch more that I forgot...

Global

Primitive prototype additions

• String#namespace: String - namespace part of namespaced string, aka of "minecraft:oak_planks" it's "minecraft". Defaults to "minecraft" if there's no :.
• String#path: String - path part of namespaced string, aka of "minecraft:oak_planks" it's "oak_planks"

Constants

• SECOND: Number = 1000
• MINUTE: Number = 60000 (60 * SECOND)
• HOUR: Number = 3600000 (60 * MINUTE)

Objects

• global: Map<String, Object>
• console: Console

Classes

• Platform
• ResourceLocation
• Utils
• Java
• Text
• UUID
• JsonIO
• Block
• Item
• Ingredient
• IngredientHelper
• NBT
• NBTIO
• Direction
• Facing
• AABB
• Fluid
• Color
• BlockStatePredicate
  

Wrapped Classes

Name	Class
JavaMath	java.lang.Math
Blocks	net.minecraft.world.level.block.Blocks
Items	net.minecraft.world.item.Items
Stats	net.minecraft.stats.Stats
DecorationGenerationStep	net.minecraft.world.level.levelgen.GenerationStep.Decoration
CarvingGenerationStep	net.minecraft.world.level.levelgen.GenerationStep.Carving
BlockPos	net.minecraft.core.BlockPos
DamageSource	net.minecraft.world.damagesource.DamageSource
BlockProperties	net.minecraft.world.level.block.state.properties.BlockStateProperties
Vec3, Vec3d	net.minecraft.world.phys.Vec3
Vec3i	net.minecraft.core.Vec3i