Getting Started with scripts

Crafttweaker uses a custom scripting Language called ZenScript, ZenScript is read from .zs files that are stored in the <gamedir>/scripts folder.

ZenScript is a “top down” scripting language, meaning that, Imports need to be at the top of the file, Variable Declarions should be near the top of the file, however there are no restrictions to that, a Variable can be defined anywhere in a script, however it will not be accessible to the lines above the Variable declaration.


Ever went into building a modpack and then found that just throwing in a bunch of mods didn’t give you an integrated experience? As mods are developed relatively independently from each other, one may feel overpowered in comparison to the other. Or you may believe that there would be a better recipe for some of the items. Or perhaps you’d want to remove an item from the game without having to remove the entire mod. Or you may discover that some ore dictionary entries have too many or too few items. Now you can do all of that - each with just a single instruction to MineTweaker.

In addition to the core functionality provided to support Vanilla minecraft, mod integration libraries are provided with the mod to enable you to not only modify vanilla recipes, but also the mod machine recipes and mod behavior.


Scripts are stored in <minecraftdir>/scripts and are loaded in the PreInitialization phase of Minecraft, unlike previous versions of Crafttweaker, Scripts cannot be reloaded, this is due to changes that Mojang have made in 1.12 and there is no workaround. Also, Scripts need to be on both, the server AND the client instance to work

Script files have the .zs prefix and can be compressed into a .zip that will also be read.

Writing your first script

To get started with Scripts, you can create a very basic file, called hello.zs in the <minecraftdir>/scripts> folder.

In hello.zs put the following line

print("Hello world!");

Now load up Minecraft and and take a look at the crafttweaker.log file.

The crafttweaker.log file is located in <minecraftdir> and can be read by any program that can read plaintext files.

It is recommended to use Notepad++ or Sublime Text to edit script files, however any program will do.

The crafttweaker.log file

The crafttweaker.log file uses a specific syntax in it’s output, that syntax is:


Using the example above, the output would be:


The syntax is used for debug purposes and the only time the syntax is not used, is for command dumps, in which case it just prints the message, this is done so copy pasting the dumps is easier.


Comments can be used to make your script files more readable and easier to understand!

ZenScript supports 3 types of comments, being:

Single line: // I'm a single line comment!

Alternate Single Line: # I'm also a single line comment!


/* I'm 
multiline comment! */