Ability Types (ability_type)

The top-level type of an ability definition comes from this table:

{"type": "mxt:active", "costs": [{"id": "example:qi", "amount": 10}], "cooldown": 40}

The common fields — the handful every type reads — are on the ability definition page. This page records only the keys each type itself reads. A key that is listed nowhere is read by nobody even when it is written.

Overview

type	What it does	Needs a key
mxt:empty	Does nothing	No
mxt:active	One press, one run	Yes
mxt:triggered	One run when a signal arrives	No
mxt:channelled	Hold to keep it up, one run per beat	Yes
mxt:targeted	One press, the payload ability on each of a batch of targets	Yes
mxt:aura	Every so often, one run on every entity in radius	No
mxt:interval	Runs itself over and over on a cadence	No
mxt:modifier	Passive attribute bonuses	No
mxt:mount	Declares the artifact a flying mount	No
mxt:flight_control	One press to take off, one to land	Yes
mxt:storage	One press opens a carried storage	Yes
mxt:upkeep	A periodic price	No
mxt:word	The two whitelisted effects	No

Needs a key only affects the wheel: only pressable types enter the wheel pool, and no other type does. Commands, scripts and item-carried abilities cast a type of any kind directly.

The Four Action Fields

entity_action, target_selector, target_condition and bi_entity_action are written at the top level of the ability (beside type), with the defaults mxt:no_op / mxt:self / mxt:always / mxt:no_op. Only the five types that run actions read them: mxt:active, mxt:triggered, mxt:channelled, mxt:aura and mxt:interval.

The order inside one run never changes: entity_action first, then target_selector picks targets, every target is tested by target_condition, and only a target that passes runs bi_entity_action. One target failing does not affect the others, and an action that throws only logs a line rather than stopping the rest.

Each of the five types runs this set at its own moment:

Type	When it runs the four keys
mxt:active	On the press (with a cast_time, the tick it finishes).
mxt:triggered	Once the trigger fires, the chance passes and the costs are paid.
mxt:channelled	Once on activation, then once per tick_interval after each upkeep deduction succeeds.
mxt:aura	A pulse that comes due on interval finds entities by radius one by one, and each entity only runs target_condition + bi_entity_action (a pulse reads neither target_selector nor entity_action); fired one-off (a command, a script, a talisman) it runs the whole set once through the ordinary path.
mxt:interval	Runs the whole set on its own interval; fired one-off by a command or a script it runs once through the ordinary path.

Every other type reads none of it: mxt:word carries a terminal payload of its own (its effect field), mxt:targeted only picks targets (it runs the payload's one-target half), and mxt:modifier / mxt:mount / mxt:flight_control / mxt:storage / mxt:upkeep / mxt:empty have no such layer either.

mxt:targeted also writes a key called target_selector, but that is its own "who does this cast reach", not half of the set above.

Which Fields Each Type Reads

type	Its own fields
mxt:empty	none
mxt:active	cooldown, the four action fields
mxt:triggered	triggers, chance, damage_condition, cooldown, the four action fields
mxt:channelled	cooldown, tick_interval, upkeep_costs, the four action fields
mxt:targeted	target_selector, ability, cooldown
mxt:aura	cooldown, interval, radius, the four action fields
mxt:interval	interval, the four action fields
mxt:modifier	modifiers
mxt:mount	speed, seats, sit, render, entity_type, display, width, height, step_height, seat_offsets, mount_action, trail
mxt:flight_control	hand, speed_multiplier, cooldown
mxt:storage	slots, cooldown
mxt:upkeep	interval, on_fail, owner_only
mxt:word	effect, requires_operator, amount, cooldown

cooldown and damage_condition are read by only some types, so they are not in the common field table — but they are still written beside type in JSON.

• cooldown (NumberProvider, default 0): the cooldown length, written into the mxt:cooldown state. Every path that pays reads it — mxt:active / mxt:triggered / mxt:channelled / mxt:aura / mxt:word / mxt:targeted / mxt:flight_control / mxt:storage. A type that pays nothing reads nothing from it.
• damage_condition (DamageCondition, default mxt:always): only mxt:triggered reads it. Subscribing to the mxt:hurt signal tests this condition first and skips that signal while it fails. Written on any other type it is a key nobody reads; to pick a situation, use condition.

State Kinds

Which state kinds an ability can store is decided by its type; a data pack does not declare it. This table decides whether mxt:modify_ability_storage and the six mxt:ability_storage_* conditions accept a value:

type	Declared state kinds
mxt:empty / mxt:modifier / mxt:mount / mxt:upkeep	Only the default mxt:active_state
mxt:active / mxt:triggered / mxt:channelled / mxt:aura	mxt:active_state, mxt:cooldown, and mxt:charges when charges is written, plus mxt:toggle / mxt:timer / mxt:resource / mxt:target_lock
mxt:interval	mxt:active_state and those four content-side kinds; no mxt:cooldown and no mxt:charges
mxt:targeted	mxt:active_state, mxt:cooldown, and mxt:charges when charges is written; none of those four
mxt:flight_control	mxt:active_state, mxt:cooldown
mxt:storage	mxt:active_state, mxt:cooldown, mxt:container
mxt:word	mxt:active_state, mxt:cooldown, and mxt:charges when charges is written

The fields of those six kinds, how they are written and how they are read are on Ability Casting.

mxt:empty

No fields and no lifecycle: {"type": "mxt:empty"} is the whole ability. Useful as a placeholder, or where all you want is to grant an id.

mxt:active

One press runs the four action fields once; with a cast_time it is the tick the cast finishes on.

Field	Type	Default	Description
cooldown	NumberProvider	0	Cooldown length, in ticks
entity_action	EntityAction	mxt:no_op	Runs on the caster first
target_selector	TargetSelector	mxt:self	How targets are picked
target_condition	BiEntityCondition	mxt:always	Every target has to pass it
bi_entity_action	BiEntityAction	mxt:no_op	Only targets that pass the condition run it

It has no slot field. Which wheel cell an ability sits in is the player's own twelve-cell layout, nothing to do with the definition.

{
  "type": "mxt:active",
  "costs": [{"id": "example:qi", "amount": 10}],
  "cooldown": 40,
  "entity_action": {"type": "mxt:spawn_particles", "particle": {"type": "minecraft:flame"}},
  "target_selector": {"type": "mxt:ray", "length": 16},
  "target_condition": {"type": "mxt:not_owner"},
  "bi_entity_action": {"type": "mxt:set_on_fire", "ticks": 60}
}

mxt:triggered

Once a signal in triggers arrives, chance passes and the costs are paid, the four action fields run once.

Field	Type	Default	Description
triggers	Trigger list	[]	An empty list means it never triggers
chance	NumberProvider	1	Whether this one counts
damage_condition	DamageCondition	mxt:always	Only used on the mxt:hurt signal
cooldown	NumberProvider	0	Cooldown length
entity_action	EntityAction	mxt:no_op	Runs on the caster first
target_selector	TargetSelector	mxt:self	How targets are picked
target_condition	BiEntityCondition	mxt:always	Every target has to pass it
bi_entity_action	BiEntityAction	mxt:no_op	Only targets that pass the condition run it

How chance is read: an evaluation that throws or is not finite does not pass, ≤ 0 does not pass, ≥ 1 always passes, and anything in between rolls the entity's random once. This is not the same rule as the chance of the same name in the trigger rules, where a value that cannot be computed counts as 1.

{
  "type": "mxt:triggered",
  "triggers": [{"type": "mxt:item_use"}],
  "costs": [{"id": "example:qi", "amount": "10 + level"}],
  "cooldown": 100,
  "condition": {"type": "mxt:sneaking"},
  "entity_action": {"type": "mxt:spawn_particles", "particle": {"type": "minecraft:crit"}},
  "target_selector": {"type": "mxt:ray", "length": 6, "limit": 1},
  "target_condition": {"type": "mxt:not_owner"},
  "bi_entity_action": {"type": "mxt:damage", "amount": "6 + level"}
}

mxt:channelled

The activation itself is a full cast; after that it is kept up once every tick_interval: condition is tested first, then upkeep_costs are charged all or nothing, and only on success do the four action fields run. A failure at any step stops the channel.

Field	Type	Default	Description
cooldown	NumberProvider	0	Cooldown length
tick_interval	NumberProvider	1	Ticks between two upkeep payments
upkeep_costs	Cost list	[]	What each upkeep costs
entity_action	EntityAction	mxt:no_op	Runs on the caster first, on activation and on every upkeep
target_selector	TargetSelector	mxt:self	How targets are picked
target_condition	BiEntityCondition	mxt:always	Every target has to pass it
bi_entity_action	BiEntityAction	mxt:no_op	Only targets that pass the condition run it

{
  "type": "mxt:channelled",
  "tick_interval": 20,
  "upkeep_costs": [{"id": "example:qi", "amount": 1}],
  "entity_action": {"type": "mxt:add_resource", "resource": "example:qi", "amount": 2}
}

mxt:targeted

One press runs one full cast, uses target_selector to pick targets, and then runs the payload ability ability's one-target half on each of them: the payload's target_condition filters, the payload's bi_entity_action happens, and the actor stays whoever pressed.

Field	Type	Default	Description
target_selector	TargetSelector	required	Who this cast reaches; the distance and the shape are written here
ability	Ability id	required	The payload ability run on every target
cooldown	NumberProvider	0	Cooldown length

The payload takes concrete ids only, never a #tag, and it has to be one of the five types that run the four action fields; naming mxt:modifier / mxt:word / another mxt:targeted is refused before anything is paid.

None of the payload's own costs / cast_time / cooldown / charges / condition / element affinity is read, and neither are its entity_action and target_selector.

Picking nobody at all (or having every pick filtered out by the payload's target_condition) is NO_TARGET; a payload type with no one-target half is NOT_APPLICABLE. Both are decided before anything is paid.

mxt:aura

Every interval ticks it runs one pulse around itself.

Field	Type	Default	Description
cooldown	NumberProvider	0	Cooldown length
interval	NumberProvider	20	Ticks between two pulses
radius	NumberProvider	4	How far a pulse reaches
entity_action	EntityAction	mxt:no_op	Runs on the caster first when fired one-off; a pulse does not read it
target_selector	TargetSelector	mxt:self	How targets are picked when fired one-off; a pulse does not read it
target_condition	BiEntityCondition	mxt:always	Every entity in range has to pass it
bi_entity_action	BiEntityAction	mxt:no_op	Only in-range targets that pass the condition run it

A pulse picks entities by radius alone: a sphere centred on the caster, comparing each target's straight-line distance, reading neither target_selector nor entity_action. A radius that evaluates non-finite or negative skips that beat. A pulse puts two extra formula variables, aura_radius and distance, on the bi-entity context.

Fired one-off by a command, a script or a talisman, it runs the whole set once through the ordinary path.

Mind that mxt:aura's radius is a sphere while the mxt:area selector's radius is a box. Same name, but they do not cover the same entities.

mxt:interval

It runs itself over and over on a cadence: every interval ticks (the ticks world time divides by it) while it counts as in effect, one full pass over the four action fields.

Field	Type	Default	Description
interval	NumberProvider	20	Ticks between two passes
entity_action	EntityAction	mxt:no_op	Runs on the caster first
target_selector	TargetSelector	mxt:self	How targets are picked
target_condition	BiEntityCondition	mxt:always	Every target has to pass it
bi_entity_action	BiEntityAction	mxt:no_op	Only targets that pass the condition run it

An interval that yields no usable tick count (not finite, or below 1) skips that beat. Fired one-off by a command or a script it ignores its cadence and runs once straight away.

It pays nothing, so it has no cooldown and no charges.

mxt:modifier

While it is granted, modifiers are contributed to the holder's vanilla attributes and condition is tested again every tick; when it fails, the contribution is withdrawn.

Field	Type	Default	Description
modifiers	AttributeEntry list	[]	Attribute modifiers

Each AttributeEntry is attribute plus id / amount / operation, with an optional value: with value written the modifier is evaluated from it, otherwise from amount (recomputed every tick). The field details are on Shared Data Types.

An amount that is not finite is not a load error; that entry is skipped at runtime.

It is not a pressable type, it runs no entity_action, and it never enters the wheel pool.

{
  "type": "mxt:modifier",
  "modifiers": [
    {"attribute": "minecraft:attack_damage", "id": "example:blade", "amount": 2, "operation": "add_value"}
  ]
}

mxt:mount

A mxt:mount is how an artifact declares itself a flying mount: once it is in the artifact's abilities, the flying skill can take it from either hand and fly it — how fast, how many seats, what fuel it burns and what it looks like are all answered here. It is never activated: it reads only its own fields, the top-level costs (the fuel of every tick) and condition (re-read every tick, and failing it lands).

Field	Type	Default	Description
speed	NumberProvider	required	Mount speed
seats	int	1	Total seats including the driver, from 1 to 4
sit	bool	false	Riding pose, shared by the whole vehicle
render	Renderer	mxt:item	Which renderer draws the mount
entity_type	entity type id	mxt:flying_sword	Which entity type flies it; it has to implement the mount contract, and a wrong id fails at load
display	{translation, rotation, scale}	absent means the renderer's own default pose	How the mount sits relative to the mount's origin
width	double	0.35	Collision box width
height	double	0.12	Collision box height
step_height	double	0	Step height
seat_offsets	Vec3 list	spread behind by 0.8 per seat, the first at 0.65 high	Where each seat lands, in blocks
mount_action	{on_mount, on_dismount, tick}	all three are mxt:no_op	The mount's own three behaviours
trail	Object	absent means no trail	Trail particles

entity_type swaps "which entity flies it": leave it out and the framework's own mxt:flying_sword is used; write it and the id is looked up in the vanilla entity type registry, where a wrong id fails at load. Whether the body can carry a flight is the entity's own answer — the type has to implement the mount contract, or take-off is refused (the action bar still reports "cannot be boarded", and the log names the type, once per type). A different entity type is a different set of behaviour: movement, landing, seats, boarding, size, saved data and drawing all live on that entity, and the definition's width / height / seat_offsets / sit / step_height / render / display have to be read by it as well — which is why "boat / palanquin / airship" is an addon registering one entity type and one renderer, with a pack naming it.

costs is the fuel of every tick: the artifact's own store of the same aura is spent first, and only the remainder falls to the driver; fractions are allowed.

render picks which renderer draws it: mxt:item by default (the item model of the carried item), mxt:geckolib (a GeckoLib model and its animations, which needs GeckoLib on the client), or a type a content mod registered. display is optional; leave it out and the renderer uses its own default pose ([0,0,0] / [90,0,-45] / [2,2,2] on the item track, no rotation and 1 on the GeckoLib track). Its fields have the same names and meanings as a vanilla item model's display: translation is written in 1/16 blocks and stored in blocks, rotation is degrees combined as rotationXYZ, and scale is a factor (a negative value mirrors, which is legal). The three render.type values, the GeckoLib asset paths and the seven poses are on Mount Renderers. Changing the collision box takes effect at once.

The last seat_offsets entry written is reused for any seats past the list. seats is the total head count including the driver; the driver has to be a player, and any other seat is taken by right-clicking the mount. The driver steers with the movement keys: jump climbs, the descend key sinks, sprinting gives 1.5x horizontal speed, and forward/back/left/right follow the look direction by default (Server Config → Flight → Fly Where You Look); sneaking is still the vanilla dismount. Movement is computed on the server only.

All three behaviours of mount_action run on the driver: the moment the flight starts, the moment it lands (before the seat is given up), and every tick (once the fuel is paid).

trail's fields are particle (required) plus interval (default 1, 1–200), count (default 1, 0–256), speed (default 0), spread (default [0.2, 0.1, 0.2]), offset_x / offset_y / offset_z (default 0 / 0.1 / 0) and moving_only (default false). particle has to be written as an object, for example {"type": "minecraft:end_rod"}; a bare id string is a load error. spread and offset_* are measured in blocks (unlike mxt:spawn_particles, which scales by the entity's size); with moving_only on, it only emits on a tick where it really moved.

Load-time refusals: seats outside 1–4, more than four seat_offsets entries or a non-finite vector among them, a non-positive or non-finite width / height, a negative or non-finite step_height, a non-finite speed / spread / offset_* on trail, and an out-of-range trail.interval / trail.count.

Hitting a block or the ground lands the flight.

mxt:flight_control

One press takes the flying artifact out of the main hand, then the off hand, and takes off; a second press lands. A technique usually grants it.

Field	Type	Default	Description
hand	main / off / either	either	Which hand the mount is looked for in
speed_multiplier	NumberProvider	1	Multiplied into the mount's speed
cooldown	NumberProvider	0	Cooldown length

It reads costs, condition, cooldown and the display fields. It reads none of cast_time / charges / the four action fields / damage_condition / element affinity.

Neither it nor mxt:storage spends a charge.

mxt:storage

One press opens the carried item's own storage. It needs an item to carry it.

Field	Type	Default	Description
slots	NumberProvider	required	Storage slot count
cooldown	NumberProvider	0	Cooldown length

How the slot count settles: floor(value) → clamped to the 32-bit integer range, 0 at the bottom → anything ≤ 0 counts as 0 (a press then reports INVALID_FORMULA) → rows clamp((slots + 8) / 9, 0, 6) → capacity = rows x 9, 54 slots at most.

Failure reasons on a press: not a server-side player = UNAVAILABLE, nothing carried in hand = NO_CARRIER, not the owner = NOT_OWNED.

The contents live in the item component mxt:storage, as one record under this ability's own id. Two storage abilities on one carrier keep two separate boxes.

It spends no charge either.

mxt:upkeep

A periodic price: every server tick the carriers in the hands of online players (main hand, off hand, every Curios slot) are looked at, and every interval ticks each one's own costs are charged all or nothing. It needs an item to carry it.

Field	Type	Default	Description
interval	NumberProvider	20	Ticks between two settlements
on_fail	ItemAction	mxt:no_op	Runs on the holder and that stack when the price cannot be paid
owner_only	Boolean	true	Only the owner pays; with false, whoever carries it pays

interval runs on the world's clock and only settles on ticks divisible by it; when the evaluation is unusable (not finite, below 1, or beyond the 64-bit integer range) it falls back to the default 20, rather than becoming every tick.

When settlement is skipped: the stack carries no mxt:upkeep, costs is empty, owner_only is true and the holder is not the owner, or the current tick is not divisible by interval.

It is not a pressable type.

mxt:word

A terminal payload: it executes no target behaviour of its own.

Field	Type	Default	Description
effect	self_heal / purge_self_curses	required	The effect; an unknown value is a load error
requires_operator	Boolean	true	The caster has to be a player with gamemaster permission
amount	NumberProvider	0	The magnitude passed to the effect, only meaningful for self_heal
cooldown	NumberProvider	0	Cooldown length

effect is a fixed whitelist; a data pack cannot add a third value. It is not an arbitrary command string and has nothing to do with the action fields on an ability — for anything else, write an ability with an entity_action (such as mxt:heal).

amount has to evaluate finite, non-negative and no larger than a single-precision float allows, or this cast is refused with PERMISSION_DENIED. Failing requires_operator refuses it the same way.

It is not a pressable type; it is cast by a command or a script.