Item Inputs and Outputs

The Thermal Crusher already knows how to process slot 3 into slot 4. Item IO adds an automation policy around those slots:

input_1  -> automation may insert into slot 3
output_1 -> automation may extract from slot 4
disabled -> the face exposes neither slot

The recipe code does not change which slot it reads or writes.

1. Import the IO registry

Update the DoriosCore import in the crusher script:

BP/scripts/examples/machines/thermalCrusher.js

import { Machine, registerIOInterface } from "DoriosCore/index.js";

Keep the required import style. Do not import from a private DoriosCore file.

2. Define the slot layout

Add these constants near the top of the module:

const BLOCK_ID = "utilitycraft:example_thermal_crusher";
const INPUT_SLOT = 3;
const OUTPUT_SLOT = 4;
const ITEM_IO_BUTTON_SLOTS = [9, 14];

[9, 14] is an inclusive button range. It expands to:

[9, 10, 11, 12, 13, 14]

Exactly six slots are required because the interface creates one button for each machine face.

3. Register the item policy

Register IO once at module load, before the block component registration:

BP/scripts/examples/machines/thermalCrusher.js

registerIOInterface(BLOCK_ID, {
  items: {
    buttonSlots: ITEM_IO_BUTTON_SLOTS,
    anyInputSlots: [INPUT_SLOT],
    anyOutputSlots: [OUTPUT_SLOT],
    modes: [
      { id: "disabled" },
      { id: "input_1", inputSlots: [INPUT_SLOT] },
      { id: "output_1", outputSlots: [OUTPUT_SLOT] },
    ],
  },
});

Do not register this inside onTick(). The policy is static for the block type and should be installed only once when the module loads.

Configuration fields

Field	Value	Meaning
buttonSlots	[9, 14]	Six helper-entity slots containing the clickable face buttons.
anyInputSlots	[3]	Input fallback for transfers without a known physical face.
anyOutputSlots	[4]	Output fallback for transfers without a known physical face.
modes	array	Ordered choices cycled independently by every face.

The any* arrays are not a seventh face and do not enable every physical side. They are used when an adapter or link path cannot provide a direction.

Every fallback slot must also appear in a corresponding mode. For example, anyInputSlots: [3] is valid because input_1 declares inputSlots: [3].

Mode fields

Field	Required	Meaning
id	Yes	Exact visual state written into the face button.
inputSlots	For an input mode	Machine inventory slots automation may fill.
outputSlots	For an output mode	Machine inventory slots automation may drain.

disabled must not declare inputs or outputs. Every other mode must expose at least one slot.

For a machine with two distinct inputs, the same pattern can expose separate modes:

modes: [
  { id: "disabled" },
  { id: "input_1", inputSlots: [3] },
  { id: "input_2", inputSlots: [4] },
  { id: "output_1", outputSlots: [5] },
]

Use only visual IDs supported by UtilityCraft UI Core. input_1 through input_9 and output_1 through output_9 have matching numbered outlines. An invented ID can still enter the runtime configuration but has no matching outline and appears to disappear in the UI.

4. Process transfers

Call processIO() once after the machine is valid:

onTick({ block }, { params: settings }) {
  const machine = new Machine(block, settings);
  if (!machine.valid) return;

  machine.processIO();

  // Continue with recipe validation and processing.
}

On an enabled input face, DoriosCore pulls compatible items from the adjacent container into slot 3. On an enabled output face, it pushes items from slot 4 into the adjacent container.

The registration protects automation boundaries:

• input faces cannot insert into slot 4;
• output faces cannot extract from slot 3;
• disabled faces expose neither operational slot.

Recipe validation is still required. IO decides where an item may go, not whether its identifier has a valid crusher recipe.

Optional transfer limits

The default call is appropriate for most machines. A machine can apply smaller budgets:

const moved = machine.processIO({
  maxInputSlotsScannedPerTick: 6,
  maxOutputSlotsMovedPerTick: 2,
});

Result field	Meaning
itemsMoved	Total item count transferred in this call.
inputSlotsScanned	Adjacent source slots examined while pulling.
fluidMoved	Liquid moved; remains 0 for this crusher.
gasMoved	Gas moved; remains 0 for this crusher.

Slot safety

The crusher's highest button slot is 14, so its helper entity needs at least 15 inventory slots:

{
  "entity": {
    "type": "machine",
    "inventory_size": 15
  }
}

Button slots must not overlap operational item slots. This layout is safe:

Slots	Purpose
0–2	Energy, label, and progress display.
3–4	Recipe input and output.
5–8	Reserved upgrades.
9–14	Six item IO buttons.

For the full configuration types and thrown validation errors, see the technical IO interface API.

Continue with Configure the six faces to connect these button slots to the UI.