ScriptCraft - Modding Minecraft with Javascript

ScriptCraft lets you write Minecraft Mods using Javascript - a programming language that's relatively easy to learn and use. ScriptCraft is a Minecraft Server plugin which means it must be used with a Minecraft server. Once you've downloaded and installed the Minecraft Server, then installed the ScriptCraft Plugin you can write your own Minecraft mods using Javascript.

I created ScriptCraft to make it easier for younger programmers to create their own Minecraft Mods. Mods are written using the JavaScript programming language. Once the ScriptCraft mod is installed, you can add your own new Mods by adding JavaScript (.js) files in a directory.

• If you're new to programming and want to start modding Minecraft, then Start Here.
• If you've already used Scratch, have attended a few CoderDojo sessions, or have already dabbled with JavaScript, then Start Here.
• Watch some demos of what you can do with ScriptCraft.

This is a simple mod in a file called greet.js in the scriptcraft/plugins directory:

function greet( player ) {
  echo( player, 'Hello ' + player.name );
}
exports.greet = greet;

At the in-game prompt, type:

/js greet(self)

Anything you can do using the Spigot or CanaryMod APIs in Java, you can do using ScriptCraft in JavaScript.

Description

ScriptCraft is a plugin for Minecraft Servers which lets operators, administrators and plug-in authors customize the game using JavaScript. ScriptCraft makes it easier to create your own mods. Mods can be written in Javscript and can use the full SpigotMC API or CanaryMod API. ScriptCraft works with all of the following Minecraft Server software:

• SpigotMC (Recommended)
• GlowStone
• CanaryMod

I recommend using SpigotMC because both CanaryMod and CraftBukkit are no longer being actively developed. The ScriptCraft mod also lets you enter javascript commands at the in-game prompt. To bring up the in-game prompt press the / key then type js followed by any javascript statement. For example: /js 1 + 1 will print 2.

ScriptCraft also includes many objects and functions to make building and modding easier using JavaScript. The JavaScript Drone object bundled with ScriptCraft provides an easy way to build at-scale in Minecraft. See the attached temple.js file for an example of how you can use the sample Drone plugin to create new buildings in Minecraft.

Prerequisites

ScriptCraft is a Minecraft Server Mod which only works with Minecraft for Personal computers (Windows, Mac and Linux). It does not work with X-BOX, Playstation or WiiU versions of the game. You will need to have Java version 7 or later installed. Check the version by typing java -version at a command prompt.

Installation

Before installing ScriptCraft you must first install SpigotMC which is a special version of Minecraft Server that makes it easy to customize the game.

Installing and Running SpigotMC

Follow these steps to download and install SpigotMC.

1. Download Spigot's BuildTools.jar
2. Save the BuildTools.jar file to a new directory called spigotmc.
3. Open a terminal (Mac and Linux) or command prompt (windows) window and type java -jar BuildTools.jar. This will kick off a long series of commands to "build" SpigotMC.
4. When the build is done, there will be a new file beginning with spigot and ending in .jar in the spigotmc directory. Run this file by typing java -jar spigot-1.10.2.jar (it might not be that exact name - you can list files in the directory by typing dir (Windows) or ls (Mac and Linux).
5. The server will start up then shut down very shortly afterwards. You'll need to edit a file called eula.txt - change eula=false to eula=true and save the file.
6. Run the java -jar spigot-1.10.2.jar command again - this time the server will start up. Shut it down by typing stop at the server prompt.

Installing ScriptCraft

Follow these steps to download and install ScriptCraft.

1. Download the scriptcraft.jar plugin and save it to the plugins directory and restart the server by typing java -jar spigot-1.10.2.jar.
2. At the server prompt type js 1 + 1 and hit enter. The result 2 should be displayed.

Congratulations - you've just installed your Custom Minecraft Server and are ready to begin writing your first mod!

Post Install

Once installed, a new scriptcraft/plugins directory is automatically created. All files in the scriptcraft/plugins directory will be automatically loaded when the server starts. Only players who are ops can use this plugin. You can grant a player op privileges by typing 'op ' (replacing with your own Minecraft user name) at the server console prompt or by adding the player's username to the ops.txt file in your server directory.

Launch the server, then launch the Minecraft client and create a new server connection. The IP address will be localhost . Once you've connected to your server and have entered the game, look at a ground-level block and type:

/js up().box( blocks.wool.black, 4, 9, 1 )

… This will create a black monolith structure 4 blocks wide by 9 blocks high by 1 block long. Take a look at the src/main/javascript/drone/drone.js file to see what ScriptCraft's drone can do.

If you're interested in customizing minecraft beyond just creating new buildings, take a look at the homes mod for an example of how to create a more fully-featured JavaScript plugin for Minecraft.

Your first mod - Howling blocks

Listed below is a simple mod that will make blocks 'Howl' when they're broken.

// copy and paste this code to a new file named 'scriptcraft/plugins/howling-blocks.js'
var sounds = require('sounds');
function howl(event){
  sounds.entityWolfHowl( event.block );
}
events.blockBreak( howl );

If you're using CanaryMod instead of SpigotMC you can download the equivalent code.

A JavaScript mod for minecraft is just a JavaScript source file (.js) located in the scriptcraft/plugins directory. All .js files in this directory will be automatically loaded when the server starts.

To get started writing your own mod, take a look at some of the examples.

Additional information

Because the SpigotMC API is open, all of the SpigotMC API is accessible via javascript once the ScriptCraft plugin is loaded. There are a couple of useful Java objects exposed via javascript in the ScriptCraft plugin:

• __plugin – the ScriptCraft Plugin itself. This is a useful starting point for accessing other SpigotMC objects. The __plugin object is of type org.bukkit.plugin.Plugin and all of its properties and methods are accessible. For example: js __plugin.name returns the plugin's name (JavaScript is more concise than the equivalent Java code: __plugin.getName() ).

• server – The top-level org.bukkit.Server object. See the SpigotMC API docs for reference.

• self – The player/command-block or server console operator who invoked the /js command. Again, this is a good jumping off point for diving into the SpigotMC API.

Contributing

If you would like to contribute source code and/or documentation changes please read contributing.md

Status

Bukkit Configuration

(You can ignore this if using CanaryMod)

ScriptCraft works with Bukkit Plugin and uses the Bukkit Configuration API. On first loading, ScriptCraft will create a config.yml file in the plugins/scriptcraft/ directory. This file looks like this:

extract-js:
  plugins: true
  modules: true
  lib: true

This file allows scriptcraft admins to turn on or off re-unzipping of the modules, plugins and lib folders when deploying a new version of ScriptCraft. It's strongly recommended that the lib directory always be set to true to get the latest core ScriptCraft code . The modules and plugins directories are optional and not part of ScriptCraft core.

Further Reading

ScriptCraft has its own website with further information.

• To get started using ScriptCraft to Learn JavaScript, read The Young Person's Guide to Programming in Minecraft.
• The ScriptCraft API documentation.
• To delve deeper into creating your own minecraft mod for use by others, read Creating a complete Minecraft Mod in JavaScript.
• Take a look at some examples.
• Buy the Official ScriptCraft Book A Beginner's Guide to Writing Minecraft Plugins in Javascript.

You can find more information about ScriptCraft on my blog.

Additional Resources

CoderDojo Athenry have some excellent tutorials for younger programmers who have used Scratch and are interested in Modding Minecraft using JavaScript. In particular, they have an excellent Scratch - to - JavaScript tutorial which explains Scratch programs and how to do the same thing in JavaScript.

I highly recommend the series of tutorials provided by CoderDojo Athenry.

Developer Chris Cacciatore has created some interesting tools using ScriptCraft:

• A wolf-bot
• L-Systems (Large-scale fractal structures in Minecraft)

Docker

To launch a container with SpigotMC and ScriptCraft you can just do

  docker run -p 25565:25565 -it tclavier/scriptcraft

You can find all files used to build this container in github project: docker-scriptcraft