Item Condition Types

An item condition checks a single item stack and returns true or false. The holder entity and the stack are supplied by whatever data table declares the condition, so the condition itself only describes what to check about the stack it is given.

Item conditions are a Java (built-in) registry, so their type ids are fixed and a data pack cannot add new ones. type selects the built-in type and its value is one of the ids tabulated on this page, written with the mxt namespace. A data pack never adds or removes entries in this registry. Only Java code or the KubeJS bridge can introduce custom condition types — see the KubeJS API.

In the table below, a field name followed by ? is optional; every other listed field must be present. The Fields column lists the JSON keys taken directly from the type's codec.

Common Structure

A condition is a JSON object whose type field names the built-in type. All remaining keys are the fields declared by that type.

{
  "type": "mxt:item_tag",
  "tag": "minecraft:swords"
}

Because conditions are used as values inside other data tables, the same structure usually appears nested under a field such as item_condition:

"item_condition": {
  "type": "mxt:relative_durability",
  "comparison": "<=",
  "compare_to": 0.25
}

Anywhere an item condition is expected, an array of conditions is also accepted. The array is shorthand for mxt:and and passes only when every entry passes:

"item_condition": [
  { "type": "mxt:item_tag", "tag": "minecraft:swords" },
  { "type": "mxt:relative_durability", "comparison": ">", "compare_to": 0.5 }
]

Where Item Conditions Run

The stack to test is normally supplied by the declaring table, for example through the mxt:equipped_item entity condition or an item action field. The comparison operators are ==, !=, <, <=, > and >=.

Datapack Visual Editor

The Datapack Visual Editor shows the field list of every type interactively, which is handy for checking a field name without reading the table here.

Condition Types

Type	Fields	Description
mxt:always_true	—	Always passes.
mxt:js	id, params?	Calls an item condition handler that was registered through the KubeJS bridge.
mxt:and	conditions	Passes only when every nested item condition passes.
mxt:or	conditions	Passes when at least one nested item condition passes.
mxt:not	condition	Negates a nested item condition.
mxt:chance	chance	Passes randomly with the given probability between 0 and 1.
mxt:constant	value	Always returns the given boolean value.
mxt:item_id	item	Matches the stack's item id.
mxt:owned_by	—	Passes when the stack's artifact owner is the current holder.
mxt:energy_range	min, max	Checks that the stack's artifact spirit energy lies between min and max.
mxt:item_tag	tag	Matches the stack against a vanilla or data pack item tag.
mxt:item_matcher	items	Matches any item id, item tag or typed matcher entry listed in one value.
mxt:amount	comparison, compare_to	Compares the stack's count.
mxt:fuel	comparison, compare_to	Compares the stack's furnace burn time.
mxt:is_equipable	slot?	Checks that the stack has an equippable component, optionally for one specific equipment slot.
mxt:relative_durability	comparison, compare_to	Compares the stack's remaining durability divided by its maximum durability.
mxt:armor_value	comparison, compare_to	Compares the armor value the stack contributes in its equippable slot.
mxt:durability	comparison, compare_to	Compares the stack's remaining durability.
mxt:on_cooldown	—	Passes when the stack is on the vanilla item cooldown of the holder.
mxt:ingredient	ingredient	Matches the stack against a vanilla ingredient.
mxt:tool_ability	ability	Checks whether the stack can perform a NeoForge item ability.
mxt:base_enchantment	enchantment, comparison, compare_to	Compares the level of one enchantment stored on the stack.
mxt:has_component	component	Checks whether the stack has the given data component.
mxt:component	component, nbt	Matches the serialized value of a data component using partial NBT comparison.
mxt:spirit_storage_not_full	—	Matches chargeable items whose stored spirit power is below their capacity.

mxt:item_matcher

The items field accepts a single value or an array, and the array may freely mix item ids, item tags and typed matcher entries. The typed entries are mxt:item, mxt:tag, mxt:wildcard, mxt:regex, mxt:herb_tag (a spirit herb carrying a given element or material tag) and the fieldless mxt:spirit_storage, which matches every item that stores aura; see Other Type Families. It is the most compact way to accept a set of items that is not already covered by an existing tag.

mxt:durability Compared With mxt:relative_durability

mxt:durability compares the raw remaining durability, so the same value means different things on items with different maximum durability. mxt:relative_durability compares the remaining fraction between 0 and 1 and is the better choice for a generic rule. Both only pass for damageable items.