Create UtilityCraft Extensions

Build your own UtilityCraft extension one working feature at a time. This learning path starts with the official addon template and gradually introduces scripted machines, energy, UI, IO, upgrades, recipes, fluids, gases, generators, reusable components, and advanced machinery.

You do not need to understand UtilityCraft's private implementation. The examples use only the public DoriosLib and DoriosCore entry points that an extension is expected to use.

Open the UtilityCraft Addon Template

New to addon scripting?

Start at Getting Started. It explains every required pack, how to download the project, how to run it with or without Regolith, and which folders you are expected to edit.

The three parts of an extension

Part	Responsibility
Your addon	Owns its blocks, items, entities, textures, recipes, scripts, namespace, and custom mechanics.
DoriosLib	Provides shared helpers and the public registries used to register components and UtilityCraft integrations.
DoriosCore	Provides the machinery-focused classes and systems used by machines, generators, storage, IO, ports, and interfaces.

UtilityCraft supplies the runtime and shared assets expected by the template. UtilityCore owns networks; DoriosCore does not.

What you will learn

The documentation is organized as a progressive course:

1. Prepare and run the official template.
2. Build a small scripted machine.
3. Give the machine a standard UtilityCraft UI and progress display.
4. Configure item, liquid, and gas IO.
5. Register and apply machine upgrades.
6. Add content to UtilityCraft registries through DoriosLib.
7. Reuse existing block and item components.
8. Create passive and active generators.
9. Move reusable addon behavior into an addon-owned core.
10. Build ports and multiblock machinery.

Documentation map

Section	Goal	Status
Getting Started	Install, inspect, and run the template safely.	Available
Your First Machine	Build a complete beginner-friendly scripted machine.	Available
Machine UI	Add slots, labels, progress, and standard tabs.	Available
Machine IO	Configure faces and item, liquid, and gas routing.	Available
Machine Upgrades	Register and consume standard and addon-owned perks.	Available
UtilityCraft Registries	Register recipes, resources, plants, fuels, and drops with DoriosLib.	Available
Reusable Components	Use existing block and item components correctly.	Available
Generators	Create passive, fuel, liquid, and gas generators.	Available
Advanced Examples	Extend DoriosCore safely and build multiblocks and ports.	Available
Machine UI Core	Look up every shared @uc.* JSON UI element.	Reference available

Rules followed throughout this course

• Import DoriosCore only from DoriosCore/index.js.
• Import DoriosLib only from DoriosLib/index.js.
• Treat the template's BP/scripts/DoriosCore and BP/scripts/DoriosLib folders as read-only dependencies.
• Put reusable addon-owned code in an addon-owned core such as MYADDON_CORE.
• Keep concrete blocks, registrations, and examples outside DoriosCore.
• Use a unique namespace and unique manifest UUIDs for a real addon.
• Validate every example against the current UtilityCraft Addon Template.

Continue with Getting Started.