Slot Data

The Slot data structure defines how an item is represented when inside an inventory window of any kind, such as a chest or furnace.

This page presents the new Slot data structure, using structured components. You can find the documentation of the old structure, that utilizes raw NBT data, here.

Format

Some description does here.

Name		Type		Meaning
Item Count		VarInt		The item count. Every following field is only present if this value is greater than zero.
Item ID		Optional VarInt		The item ID. Item IDs are distinct from block IDs; see Data Generators for more information.
Number of components to add		Optional VarInt		Number of elements present in the first data component array
Number of components to remove		Optional VarInt		Number of elements present in the second data component array. This serve as a way to remove the default component values that are present on some items.
Components to add	Component type	Optional Array	VarInt Enum	The type of component. See Structured components for more detail.
	Component data		Varies	The component-dependent data. See Structured components for more detail.
Components to remove	Component type	Optional Array	VarInt Enum	The type of component. See Structured components for more detail.

Structured components

The complete list of available components is described below. Items marked in blue cause no noticeable impact on the client, and mainly concern server-side operations.

For a more in-depth description, and information on how the items below are encoded with the NBT format, check here.

Type	Name	Description	Data
0	minecraft:custom_data	Customizable data that doesn't fit any specific component.	As follows: Name Type Description Data NBT Always a Compound Tag.
1	minecraft:max_stack_size	Maximum stack size for the item.	As follows: Name Type Description Max Stack Size VarInt Ranges from 1 to 99.
2	minecraft:max_damage	The maximum damage the item can take before breaking.	As follows: Name Type Description Max Damage VarInt
3	minecraft:damage	The current damage of the item.	As follows: Name Type Description Damage VarInt
4	minecraft:unbreakable	Marks the item as unbrekable.	As follows: Name Type Description Show In Tooltip Boolean Whether the Unbreakable indicator should be shown on the item's tooltip.
5	minecraft:custom_name	Item's custom name. Normally shown in italic, and changeable at an anvil.	As follows: Name Type Description Name Text Component
6	minecraft:item_name	Override for the item's default name. Shown when the item has no custom name.	As follows: Name Type Description Name Text Component
7	minecraft:lore	Item's lore.	As follows: Name Type Description Number of Lines VarInt Number of elements in the following array. Lines Array of Text Component
8	minecraft:rarity	Item's rarity. This affects the default color of the item's name.	As follows: Name Type Description Rarity VarInt Enum Can be one of the following: 0 - Common (white) 1 - Uncommon (yellow) 2 - Rare (aqua) 3 - Epic (pink)
9	minecraft:enchantments	The enchantments of the item.	As follows: Name Type Description Number Of Enchantments VarInt Number of elements in the following array. Enchantment Type ID Array VarInt Enum The ID of the enchantment in the enchantment registry. Level VarInt The level of the enchantment. Show In Tooltip Boolean Whether the list of enchantments should be shown on the item's tooltip.
10	minecraft:can_place_on	List of blocks this block can be placed on when in adventure mode.	As follows: Name Type Description Number Of Predicates VarInt Number of elements in the following array. Block Predicates Array of Block Predicate See Block Predicate. Show In Tooltip Boolean Whether the Unbreakable indicator should be shown on the item's tooltip.
11	minecraft:can_break	List of blocks this item can break when in adventure mode.	As follows: Name Type Description Number Of Predicates VarInt Number of elements in the following array. Block Predicates Array of Block Predicate See Block Predicate. Show In Tooltip Boolean Whether the Unbreakable indicator should be shown on the item's tooltip.
12	minecraft:attribute_modifiers	The attribute modifiers of the item.	As follows: Name Type Description Number Of Attributes VarInt Number of elements in the following array. Attribute Type ID Array VarInt Enum The ID of the attribute. Unique ID UUID The attribute's unique ID. Name String The attribute's name. Value Double The attribute's value. Operation VarInt Enum The operation to be applied upon the value. Can be one of the following: 0 - Add 1 - Multiply base 2 - Multiply total Slot VarInt Enum The item slot placement required for the attribute to have effect. Can be one of the following: 0 - Any 1 - Main hand 2 - Off hand 3 - Hand 4 - Feet 5 - Legs 6 - Chest 7 - Head 8 - Armor 9 - Body Show In Tooltip Boolean Whether the list of attributes should be shown on the item's tooltip.
13	minecraft:custom_model_data	Value for the item predicate when using custom item models. More info can be found here.	As follows: Name Type Description Value VarInt
14	minecraft:hide_additional_tooltip	The following information needs to be added to this page: What is considered as "additional"? What exact items does this hide?	None.
15	minecraft:hide_tooltip	Hides the item's tooltip altogether.	None.
16	minecraft:repair_cost	Accumulated anvil usage cost. The client displays "Too Expensive" if the value is greater than 40 and the player is not in creative mode (more specifically, if they don't have the insta-build flag enabled). This behavior can be overridden by setting the level with the Set Container Property packet.	As follows: Name Type Description Cost VarInt
17	minecraft:creative_slot_lock	Marks the item as non-interactive on the creative inventory (the first 5 rows of items). This is used internally by the client on the paper icon in the saved hot-bars tab.	None.
18	minecraft:enchantment_glint_override	Overrides the item glint resulted from enchantments	As follows: Name Type Description Has Glint VarInt
19	minecraft:intangible_projectile	Marks the projectile as intangible (cannot be picked-up). The Notchian client utilizes the codec meant for chat parsing (and NBT in general) when handling this component, even though it contains no data. This causes an empty Compound Tag to be written, which is likely an unintended bug.	As follows: Name Type Description Value NBT Always a Compound Tag, and always empty.
20	minecraft:food	Makes the item consumable.	As follows: Name Type Description Nutrition VarInt Non-negative Saturation Boolean Can Always Eat Boolean Whether the item can always be eaten, even at full hunger. Seconds To Eat Float How long it takes to consume the item. Number of effects VarInt Number of elements in the following array. Effect Type ID Array Potion Effect The potion effect. See Potion Effect. Probability Float The probability for this effect to be chosen.
21	minecraft:fire_resistant	Marks this item as fire resistant. The client won't render the item as being on-fire if this component is present.	None.
22	minecraft:tool	Alters the speed at which this item breaks certain blocks	As follows: Name Type Description Number of Rules VarInt The number of elements in the following array. Rule Blocks Array Block Set The block this rule applies to. See Block Set. Has Speed Boolean Speed Optional Float The speed at which the tool breaks this rules' blocks. Only present if Has Speed is true. Has Correct Drop For Blocks Boolean Correct Drop For Blocks Optional Boolean Whether items should drop only if this is the correct tool. Only present if Has Correct Drop For Blocks is true. Default Mining Speed Float The mining speed in case none of the previous rule were matched. Damage Per Block VarInt The amount of damage the item takes per block break.
23	minecraft:stored_enchantments	The enchantments stored in this enchanted book.	As follows: Name Type Description Number of enchantments VarInt Number of elements in the following array. Enchantment Type ID Array VarInt Enum The ID of the enchantment in the enchantment registry. Level VarInt The level of the enchantment. Show In Tooltip Boolean Whether the list of enchantments should be shown on the item's tooltip.
24	minecraft:dyed_color	Color of dyed leather armor.	As follows: Name Type Description Color Int The RGB components of the color, encoded as an integer. Show In Tooltip Boolean Whether the armor's color should be shown on the item's tooltip.
25	minecraft:map_color	Color of the markings on the map item model.	As follows: Name Type Description Color Int The RGB components of the color, encoded as an integer.
26	minecraft:map_id	The ID of the map.	As follows: Name Type Description ID VarInt
27	minecraft:map_decorations	Icons present on a map.	As follows: Name Type Description Data NBT Always a Compound Tag.
28	minecraft:map_post_processing	Used internally by the client when expanding or locking a map. Display extra information on the item's tooltip when the component is present.	As follows: Name Type Description Type VarInt Enum Type of post processing. Can be either: 0 - Lock 1 - Scale
29	minecraft:charged_projectiles	Projectiles loaded into a charged crossbow.	As follows: Name Type Description Number Of Projectiles VarInt The number of elements in the following array. Projectiles Array of Slot The projectiles.
30	minecraft:bundle_contents	Contents of a bundle.	As follows: Name Type Description Number Of Items VarInt The number of elements in the following array. Items Array of Slot The projectiles.
31	minecraft:potion_contents	Visual and effects of a potion item.	As follows: Name Type Description Potion ID VarInt The ID of the potion type in the potion registry. Has Custom Color Boolean Whether this potion has a custom color. If false, it uses the default color associated with the potion type. Custom Color Int The RGB components of the color, encoded as an integer. Number Of Custom Effects VarInt The number of elements in the following array. Custom Effects Array of Potion Effect Any custom effects the potion might have. See Potion Effect.
32	minecraft:suspicious_stew_effects	Effects granted by a suspicious stew.	As follows: Name Type Description Number Of Effects VarInt Number of elements in the following array. Effect Type ID Array VarInt Enum The ID of the effect in the potion effect type registry. Duration VarInt The duration of the effect.
33	minecraft:writable_book_content	Content of a writable book.	As follows: Name Type Description Number Of Pages VarInt Number of elements in the following array. Page Raw Content Array (100) String (1024) The raw text of the page. Has Filtered Content Boolean Filtered Content Optional String (1024) The content after passing through chat filters. Only present if Has Filtered Content is true.
34	minecraft:written_book_content	Content of a written and signed book.	As follows: Name Type Description Raw Title String (32) The raw title of the book. Has Filtered Title Boolean Filtered Title Optional String (32) The title after going through chat filters. Only present if Has Filtered Title is true. Author String Generation VarInt Number Of Pages VarInt Number of elements in the following array. Page Raw Content Array (100) TextComponent (1024) The raw text of the page. Has Filtered Content Boolean Filtered Content Optional Text Component (1024) The content after passing through chat filters. Only present if Has Filtered Content is true. Resolved Boolean Whether entity selectors have already been resolved.
35	minecraft:trim	Armor's trim pattern and color	As follows: Name Type Description Trim Material Type VarInt Identifier used to determine the data that follows. It can be either: 0 - Directly represents a trim material, with the necessary data following. Anything else - References a trim material in its registry, by the ID of Trim Material Type - 1. Asset Name Optional String See Armor Trim Material Registry. Only present if Trim Material Type is 0. Ingredient Optional VarInt See Armor Trim Material Registry. Only present if Trim Material Type is 0. Item Model Index Optional Float See Armor Trim Material Registry. Only present if Trim Material Type is 0. Number of Overrides Optional VarInt See Armor Trim Material Registry. Only present if Trim Material Type is 0. Override Armor Material Type Optional Array VarInt Enum See Armor Trim Material Registry. Only present if Trim Material Type is 0. Overriden Asset Name String See Armor Trim Material Registry. Only present if Trim Material Type is 0. Description Optional Text Component See Armor Trim Material Registry. Only present if Trim Material Type is 0. Trim Pattern Type VarInt Identifier used to determine the data that follows. It can be either: 0 - Directly represents a trim pattern, with the necessary data following. Anything else - References a trim pattern in its registry, by the ID of Trim Pattern Type - 1. Asset Name Optional String See Armor Trim Pattern Registry. Only present if Trim Pattern Type is 0. Template Item Optional VarInt See Armor Trim Pattern Registry. Only present if Trim Pattern Type is 0. Description Optional Text Component See Armor Trim Pattern Registry. Only present if Trim Pattern Type is 0. Decal Optional Boolean See Armor Trim Pattern Registry. Only present if Trim Pattern Type is 0. Show In Tooltip Boolean Whether the trim information should be shown on the item's tooltip.
36	minecraft:debug_stick_state	State of the debug stick	As follows: Name Type Description Data NBT States of previously interacted blocks. Always a Compound Tag.
37	minecraft:entity_data	Data for the entity to be created from this item.	As follows: Name Type Description Data NBT Always a Compound Tag.
38	minecraft:bucket_entity_data	Data of the entity contained in this bucket.	As follows: Name Type Description Data NBT Always a Compound Tag.
39	minecraft:block_entity_data	Data of the block entity to be created from this item.	As follows: Name Type Description Data NBT Always a Compound Tag.
40	minecraft:instrument	The sound played when using a goat horn.	As follows: Name Type Description Instrument Type VarInt Identifier used to determine the data that follows. It can be either: 0 - Directly represents an instrument, with the necessary data following. Anything else - References an instrument in its registry, by the ID of Instrument Type - 1. Sound Event Type Optional VarInt Identifier used to determine the data that follows. It can be either: 0 - Directly represents an instrument, with the necessary data following. Anything else - References an instrument in its registry, by the ID of Instrument Type - 1. Only present if Instrument Type is 0. Sound Name Optional Identifier Only present if Instrument Type and Sound Event Type are 0. Has Fixed Range Optional Boolean Whether this sound has a fixed range, as opposed to a variable volume based on distance. Only present if Instrument Type and Sound Event Type are 0. Fixed Range Optional Float The maximum range of the sound. Only present if Instrument Type and Sound Event Type are 0. Use duration Optional Float The maximum range of the sound. Only present if Instrument Type is 0. Range Optional Float The range of the instrument. Only present if Instrument Type is 0.
41	minecraft:ominous_bottle_amplifier	Amplifier for the effect of an ominous bottle.	As follows: Name Type Description Amplifier VarInt Between 0 and 4.
42	minecraft:recipes	The recipes this knowledge book unlocks.	As follows: Name Type Description Data NBT Always a Compound Tag.
43	minecraft:lodestone_tracker	The lodestone this compass points to.	As follows: Name Type Description Has Global Position Boolean Whether this lodestone points to a position, otherwise it spins randomly. Dimension Identifier The dimension the compass points to. Only present if Has Global Position is true. Position Position The position the compass points to. Only present if Has Global Position is true. Tracked Boolean Whether the component is removed when the associated lodestone is broken.
44	minecraft:firework_explosion	Properties of a firework star.	As follows: Name Type Description Explosion Firework Explosion See Firework Explosion.
45	minecraft:fireworks	Properties of a firework.	As follows: Name Type Description Flight Duration VarInt Number Of Explosions VarInt Number of elements in the following array. Explosions Array of Firework Explosion See Firework Explosion.
46	minecraft:profile	Game Profile of a player's head.	As follows: Name Type Description Has Name Boolean Name Optional String (16) Only present if Has Name is true. Has Unique ID Boolean Unique ID Optional UUID Only present if Has Unique ID is true. Number of Properties VarInt Number of elements in the following array. Property Name Array String (64) Value String Has Signature Boolean Signature String (1024) Only present if Has Signature is true.
47	minecraft:note_block_sound	Sound played by a note block when this player's head is placed on top of it.	As follows: Name Type Description Sound Identifier
48	minecraft:banner_patterns	Patterns of a banner or banner applied to a shield.	As follows: Name Type Description Number of Layers VarInt Number of elements in the following array. Layer Pattern Type Array VarInt Identifier used to determine the data that follows. It can be either: 0 - Directly represents a pattern, with the necessary data following. Anything else - References a pattern in its registry, by the ID of Pattern Type - 1. Asset ID Optional Identifier Identifier of the asset. Only present if Pattern Type is 0. Translation Key Optional String Only present if Pattern Type is 0. Color Dye Color See Dye Color.
49	minecraft:base_color	Base color of the banner applied to a shield.	As follows: Name Type Description Color Dye Color See Dye Color.
50	minecraft:pot_decorations	Decorations on the four sides of a pot.	As follows: Name Type Description Number Of Decorations VarInt The number of elements in the following array. Decorations Array (4) of VarInt Enum The ID of the items in the item registry.
51	minecraft:container	Items inside a container of any type.	As follows: Name Type Description Number Of Items VarInt The number of elements in the following array. Items Array (256) of Slot
52	minecraft:block_state	State of a block.	As follows: Name Type Description Number of Properties VarInt Number of elements in the following array. Property Name Array String Value String
53	minecraft:bees	Bees inside a hive.	As follows: Name Type Description Number of Bees VarInt Number of elements in the following array. Bee Entity Data Array NBT Custom data for the entity, always a Compound Tag. Same structure as the minecraft:custom_data component. Ticks In Hive VarInt Min Ticks In Hive VarInt
54	minecraft:lock	Name of the necessary key to open this container.	As follows: Name Type Description Key NBT Always a String Tag.
55	minecraft:container_loot	Loot table for an unopened container.	As follows: Name Type Description Data NBT Always a Compound Tag.

Other types

Common types used in multiple components are described below.

Block Predicate

Describes a predicate used when block filtering is necessary. It can be parameterized to account for the type of block, the values of specific block state properties, NBT data related to block entities, or any combination of the three.

Name	Type	Description
Has Blocks	Boolean	Whether this predicate is tied to specific types of blocks.
Blocks	Optional Block Set	See Block Set. Only present if Has Blocks is true.
Has Properties	Boolean	Whether this predicate is tied to specific properties of a block.
Number of Properties	Optional VarInt	Number of elements in the following array. Only present if Has Properties is true.
Properties	Optional Array of Property	See Property structure below. Only present if Has Properties is true.
Has NBT	Boolean	Whether this predicate is tied to specific block entity data.
NBT	Optional NBT	Only present is Has NBT is true.

The Property structure is defined as follows:

Name	Type	Description
Name	String	Name of the block state property.
Is Exact Match	Boolean	Whether this is an exact value match, as opposed to ranged.
Exact Value	Optional String	Value of the block state property. Only present in exact match mode.
Min Value	Optional String	Minimum value of the block state property range. Only present in ranged match mode.
Max Value	Optional String	Maximum value of the block state property range. Only present in ranged match mode.

Block Set

Represents a list of block types, either directly (enumerated IDs) or indirectly (block tag).

Name	Type	Description
Type	VarInt	Identifier used to determine the data that follows. It can be either: 0 - Represents a named set of blocks, defined by a tag. Anything else - Represents an enumerated set of blocks, defined by block IDs.
Tag name	Optional Identifier	A tag representing a set of blocks. Only present if Type is 0.
Block IDs	Optional Array of VarInt	An array of block IDs. Only present if Type is not 0. The size of the array is equal to Type - 1.

Dye Color

A color from one of the 16 dye types.

Name	Type	Description
Color	VarInt Enum	Can be one of the following: 0 - White 1 - Orange 2 - Magenta 3 - Light Blue 4 - Yellow 5 - Lime 6 - Pink 7 - Gray 8 - Light Gray 9 - Cyan 10 - Purple 11 - Blue 12 - Brown 13 - Green 14 - Red 15 - Black

Firework Explosion

Represents a firework explosion, consisting of a shape, colors, and extra details.

Name	Type	Description
Shape	VarInt Enum	Can be one of the following: 0 - Small ball 1 - Large ball 2 - Star 3 - Creeper 4 - Burst
Number Of Colors	VarInt	The number of elements in the following array.
Colors	Array of Int	The RGB components of the color, encoded as an integer.
Number Of Fade Colors	VarInt	The number of elements in the following array.
Fade Colors	Array of Int	The RGB components of the color, encoded as an integer.
Has Trail	Boolean
Has Twinkle	Boolean

Potion Effect

Describes all the aspects of a potion effect.

Name	Type	Description
Type ID	VarInt Enum	The ID of the effect in the potion effect type registry.
Details	Detail	See Detail structure below.

The Detail structure is defined as follows:

Name	Type	Description
Amplifier	VarInt
Duration	VarInt	-1 for infinite.
Ambient	Boolean	Produces more translucent particle effects if true.
Show Particles	Boolean	Completely hides effect particles if false.
Show Icon	Boolean	Shows the potion icon in the inventory screen if true.
Has Hidden Effect	Boolean	Used to store the state of the previous potion effect when a stronger one is applied. This guarantees that the weaker one will persist, in case it lasts longer. The following information needs to be added to this page: This behavior seems to be entirely server-sided. Does the presence of this field actually has any noticeable impact on the client?
Hidden Effect	Optional Detail	Only present if Has Hidden Effect is true.