Item Components

UtilityCraft reads parameters stored on custom item components. Your addon defines the item and attaches the existing component ID; UtilityCraft registers the behavior once.

utilitycraft:hammer

A Hammer converts a mined block through the Crusher recipe table. Its tier must meet the recipe's optional tier requirement.

BP/items/examples/example_hammer.json

{
  "format_version": "1.21.110",
  "minecraft:item": {
    "description": {
      "identifier": "utilitycraft:example_hammer",
      "menu_category": { "category": "equipment" }
    },
    "components": {
      "utilitycraft:hammer": { "tier": 2 },
      "minecraft:icon": "utilitycraft_diamond_hammer",
      "minecraft:max_stack_size": 1,
      "minecraft:hand_equipped": true,
      "minecraft:durability": { "max_durability": 512 },
      "minecraft:damage": 5,
      "minecraft:tags": {
        "tags": [
          "minecraft:is_pickaxe",
          "minecraft:is_tool",
          "utilitycraft:is_hammer"
        ]
      }
    }
  }
}

Parameter	Type	Meaning
tier	finite number	Minimum recipe tier the tool can process. A tier 2 Hammer can process recipes requiring 0, 1, or 2.

The handler looks up the exact mined block in the Crusher registry, removes its normal matching drop, and spawns the registered result and amount. Add a Crusher recipe through Add recipes to existing machines.

Durability, mining speed, damage, tags, icon, and recipe are ordinary item configuration owned by the addon; they are not supplied by the custom component.

utilitycraft:mesh

A Mesh controls Auto Sieve tier, success chance, and output amount:

BP/items/examples/example_mesh.json

{
  "format_version": "1.21.110",
  "minecraft:item": {
    "description": {
      "identifier": "utilitycraft:example_mesh",
      "menu_category": { "category": "construction" }
    },
    "components": {
      "utilitycraft:mesh": {
        "tier": 4,
        "multiplier": 1.5,
        "amount_multiplier": 1
      },
      "minecraft:icon": "utilitycraft_diamond_mesh",
      "minecraft:max_stack_size": 1,
      "minecraft:durability": { "max_durability": 768 }
    }
  }
}

Parameter	Meaning
tier	Minimum-tier gate for registered Sieve drops.
multiplier	Multiplies every eligible drop's base chance. 1.5 turns 0.08 into 0.12.
amount_multiplier	Multiplies the rolled output amount before it is rounded to a whole item. Default behavior is 1.

Manual Sieve limitation

The current Basic manual Sieve accepts only UtilityCraft's built-in Mesh item IDs. An addon-owned Mesh such as utilitycraft:example_mesh is intended for the Auto Sieve and is deliberately rejected by the manual Sieve interaction handler.

Register loot through Fishing and sieve drops.

utilitycraft:fishing_net

The Auto Fisher reads all of its equipment modifiers from the installed Fishing Net:

BP/items/examples/example_fishing_net.json

{
  "format_version": "1.21.110",
  "minecraft:item": {
    "description": {
      "identifier": "utilitycraft:example_fishing_net",
      "menu_category": { "category": "construction" }
    },
    "components": {
      "utilitycraft:fishing_net": {
        "tier": 4,
        "speed": 1.5,
        "chance_multiplier": 1.75,
        "amount_multiplier": 1,
        "rolls": 2,
        "luck": 3
      },
      "minecraft:icon": "utilitycraft_diamond_fishing_net",
      "minecraft:max_stack_size": 1,
      "minecraft:durability": { "max_durability": 768 }
    }
  }
}

Parameter	Default	Meaning
tier	0	Minimum-tier gate for loot entries.
speed	1	Multiplies the Auto Fisher processing rate.
chance_multiplier	1	Multiplies each eligible base drop chance.
amount_multiplier	1	Multiplies rolled item amounts.
rolls	1	Loot rolls performed for each completed process.
luck	0	Improves supported enchantment chances, counts, and quality for built-in enchantable loot.

Use positive, intentionally balanced values. Increasing both rolls and chance_multiplier compounds output much faster than changing either one alone.

utilitycraft:machine_upgrade

Attach this behavior to every item installed through UtilityCraft's upgrade interaction:

{
  "utilitycraft:machine_upgrade": {},
  "minecraft:max_stack_size": 4,
  "minecraft:tags": {
    "tags": ["utilitycraft:is_upgrade"]
  }
}

The component handles using the item on a compatible machine. Its perk type and level values come from DoriosLib.registry.registerMachineUpgrade(), while the machine's block component declares the accepted slot and maximum level. Follow Machine Upgrades instead of configuring these pieces independently.

Test each item

Item	Minimum test
Hammer	Mine a block with a registered Crusher recipe below and above the Hammer tier.
Mesh	Install it in an Auto Sieve, test a guaranteed drop, then restore the intended probability.
Fishing Net	Install it in an Auto Fisher near water and compare rate, eligible tier, and rolls.
Upgrade	Use and sneak-use it on a compatible machine; verify the correct slot, level cap, and perk.

Do not register any of these component IDs again. To create genuinely different behavior, define an addon-owned ID and handler with DoriosLib.registry.itemComponent().

Continue with Generators.