Simple Chat Commands

Who doesn't want cool custom commands? With the Script API, you can create your own. In this article, we will be creating them using the Script API.

Setup Pack ​

Assuming you have understood the basics of scripting, let's start creating the pack.

{
	"format_version": 2,
	"header": {
		"name": "Custom Commands",
		"description": "Custom Commands using the Script API",
		"uuid": "c8c3239f-027f-4e80-890f-880eba65027d",
		"min_engine_version": [1, 19, 40],
		"version": [1, 0, 0]
	},
	"modules": [
		{
			"description": "Behavior Pack Module",
			"type": "data",
			"uuid": "cd2cd41a-1849-410e-8f0a-5d30fde4bd9a",
			"version": [1, 0, 0]
		},
		{
			"description": "Gametest Module",
			"type": "script",
			"language": "javascript",
			"entry": "scripts/main.js",
			"uuid": "f626740d-50a6-49f1-a24a-834983b72134",
			"version": [1, 0, 0]
		}
	],
	"dependencies": [
		{
			"module_name": "@minecraft/server",
			"version": "1.15.0-beta" // needs to be the latest or it will break ( latest as of 1.21.30 )
		}
  ]
}

In our manifest, we have added script module. The entry is where our script file is stored. This is typically within the scripts folder of the behavior pack. The dependency allows us to use that script module in our script.

Creating Custom Commands ​

Now comes the fun part - creating our custom commands. First, we will add the module.

import { world } from '@minecraft/server';

Next, we will add simple commands, such as !gmc to change our gamemode to creative and !gms to change into survival.

world.beforeEvents.chatSend.subscribe((eventData) => {
	const player = eventData.sender;
	switch (eventData.message) {
		case '!gmc':
			eventData.cancel = true;
			player.runCommandAsync('gamemode c');
			break;
		case '!gms':
			eventData.cancel = true;
			player.runCommandAsync('gamemode s');
			break;
		default: break;
	}
});

This is the main function to execute our commands. world.beforeEvents.chatSend.subscribe() will run before chat messages get sent.

• A switch statement runs through the possible options for the value, and if it matches, runs the code until the next break statement.
• eventData.cancel = true will cancel the chat message that will be sent- similar to how vanilla commands work.
• const player = eventData.sender declares the variable player to be used later.
• player.runCommandAsync('gamemode c') runs the command on the sender of the message.

Limited Command Usage by Tags ​

This function will always be checking if the player types the special message to activate the command, even if the player shouldn't have access. To prevent this, we can use tags to limit these commands to specific people.

For example, let's make our commands usable only to players that have the Admin tag.

import { world } from "@minecraft/server";

world.beforeEvents.chatSend.subscribe((eventData) => {
	const player = eventData.sender;
	if (!player.hasTag('Admin')) return;
	switch (eventData.message) {
		case '!gmc':
			eventData.cancel = true;
			player.runCommandAsync('gamemode c');
			break;
		case '!gms':
			eventData.cancel = true;
			player.runCommandAsync('gamemode s');
			break;
		default: break;
	}
});

In plain text, if (!eventData.sender.hasTag('Admin')) return; means: "If the player does NOT (!) have the 'Admin' tag, stop the script from running past here (return)"

For more information about the Script API, you can reference the wiki or the Microsoft Docs