Project Setup

The com.mojang Folder

The com.mojang folder is Minecraft's home for crucial data like Add-ons, Worlds, settings, and player information. Your development packs go directly into specific subfolders here, while saved worlds are usually found in minecraftWorlds.

Finding Your com.mojang Folder:

The exact location varies by operating system and Minecraft version. Below are common paths. You might need to enable viewing hidden files/folders.

Development Packs

For rapid development, we use special folders: development_behavior_packs and development_resource_packs. These live directly inside the main com.mojang folder (use the primary Windows UWP/Store path or equivalent for your OS).

The standard resource_packs and behavior_packs folders are typically for add-ons imported via .mcpack files or from the Marketplace. We'll focus on the development_ folders.

Your Workspace

A good workspace setup makes development much smoother. We recommend using VS Code, but you can adapt these steps for any editor.

BP Manifest (manifest.json)

The manifest file, always named manifest.json, is the heart of your pack. It tells Minecraft essential information like the pack's name, description, type, and unique identifiers. It uses JSON format. If JSON is new to you, check out a quick JSON Introduction.

In your VS Code workspace, right-click within your BP folder area and select "New File". Name it exactly manifest.json. Paste the following code into it:

{    "format_version": 2,    "header": {        "name": "pack.name",        "description": "pack.description",        "uuid": "GENERATE-UUID-1", // <-- Replace with generated UUID        "version": [1, 0, 0],        "min_engine_version": [1, 20, 0] // <-- Updated example version    },    "modules": [        {            "type": "data",            "uuid": "GENERATE-UUID-2", // <-- Replace with generated UUID            "version": [1, 0, 0]        }    ],    "metadata": {        "authors": ["Your Name"], // <-- Optional: Add author info        "product_type": "addon" // Allows achievements if desired    }}

Important: You'll need to replace the "GENERATE-UUID-..." placeholders with actual unique IDs soon. We'll cover that next.

Manifest Explained

UUID Explained

RP Manifest (manifest.json)

Now, let's create the manifest for the Resource Pack (RP). It's very similar to the BP manifest, but the module type is "resources" instead of "data".

Create a new file named manifest.json inside your RP folder. Paste in the following code.

{    "format_version": 2,    "header": {        "name": "pack.name",        "description": "pack.description",        "uuid": "GENERATE-UUID-3", // <-- Replace with new generated UUID        "version": [1, 0, 0],        "min_engine_version": [1, 20, 0] // <-- Updated example version    },    "modules": [        {            "type": "resources", // <-- Marks it as a Resource Pack            "uuid": "GENERATE-UUID-4", // <-- Replace with new generated UUID            "version": [1, 0, 0]        }    ],    "metadata": {         "authors": ["Your Name"], // <-- Optional: Add author info        "product_type": "addon"    }}

Save the RP/manifest.json file after pasting the code and the new UUIDs.

Pack Icon (pack_icon.png)

The pack icon is the image displayed for your add-on in Minecraft's menus (e.g., world settings, global resources). It must be a PNG file named exactly pack_icon.png.

Create or find a square image (e.g., 128x128 or 256x256 pixels) that represents your pack. Save it as pack_icon.png.

Place a copy of your pack_icon.png file directly inside both your RP folder and your BP folder.

Language Files (Localization Basics)

Remember how we used pack.name and pack.description in the manifests? To tell Minecraft what those actually mean, we need language files. This allows your pack's name and description (and later, item/block names) to be translated.

Create a new folder named texts inside both your RP folder and your BP folder.

Inside each texts folder, create two files:

pack.name=My Awesome RPpack.description=Resources for my awesome addon!

["en_US"]

pack.name=My Awesome BPpack.description=Behavior for my awesome addon!

["en_US"]

Checking Your Work & Test Setup

If all files are correctly named, placed, and formatted (especially the JSON!), your packs should now appear in Minecraft's pack menus when creating or editing a world.

Enable Experiments (Required for Most Features)

Many add-on features (custom blocks/items, scripting APIs, etc.) require enabling "Experimental Gameplay" toggles when creating or editing your world. To even *see* these toggles, you often need a special UI resource pack activated globally.

With this pack active globally, the necessary "Experiments" toggles will appear in the world creation screen (shown next).

Turn on Content Log (Essential for Debugging)

The Content Log displays errors and warnings from your add-ons, making it invaluable for finding problems. You *must* enable it.

Navigate to the minecraftpe folder, which is usually located *inside* your main com.mojang folder (refer to the paths listed earlier if needed, it's one level deeper than where the pack folders are).

Open options.txt with a plain text editor (Notepad, VS Code, TextEdit, etc.). Find these lines (they might be scattered):

... (other settings) ...content_log_file:1 # Set to 1 to enable file logging (can use lots of storage!)content_log_gui:1  # Set to 1 to enable on-screen log... (more settings) ...

Change the 0 to a 1 for both content_log_file and content_log_gui. Save the file and close it.

Now, when you run Minecraft and load a world with your packs, errors will appear on screen (GUI log) and potentially be saved to a log file (file log). The GUI log is usually sufficient for active development.

With the setup complete, create a new world specifically for testing your add-on using these settings:

Project Structure Overview

After following these steps, your project folders within development_resource_packs and development_behavior_packs should look like this:

What You Have Learned