Registry Data

Registries are repositories of data that contain entries pertaining to certain aspects of the game, such as the world, the player, among others.

The server sends these registries to the client via Registry Data packet during the configuration phase.

Format

Packet ID	State	Bound To	Field Name	Field Type	Notes
0x05	Configuration	Client	Registry Data	NBT Tag Compound	Information included below.

The Registry Data field represents a list of all available registries in the form of a Compound Tag. Elements in this compound are defined by the registry information, associated with the registry's name, as shown in the example below:

{
    "minecraft:dimension_type": { /* Registry */ },
    "minecraft:worldgen/biome": { /* Registry */ },
    "minecraft:chat_type": { /* Registry */ },
    ...
}

Registry

The Registry Compound Tag specifies the type of the registry, and a list of registry entries.

The name of the registry in the Registry Data is always the same to the registry type in the Notchian implementation.

Name	Type	Notes
type	TAG_String	The type of the registry.
value	TAG_List of TAG_Compound	List of registry entries.

Registry Entry

The Registry Entry Compound Tag specifies a single entry of a Registry.

Name	Type	Notes
name	TAG_String	The name of the entry.
id	TAG_Int	The protocol ID of the entry.
element	TAG_Compound	The actual data of the entry. This field is context-dependent and is based on the type field of its Registry.

Required Registries

The current release specification allows for six different registries to be sent to the client, six of which are required. A brief explanation of each of them is presented below, along with the format of their entries' element field.

Armor Trim Material

The minecraft:trim_material registry.

Armor Trim Pattern

The minecraft:trim_pattern registry.

Biome

The minecraft:worldgen/biome registry. It defines several aesthetic characteristics of the biomes present in the game.

A registry entry for each biome implemented in the client must exist in the Biome registry, otherwise the client will crash with an exception due to the missing biome.

Biome properties:

Name			Type		Meaning		Values
has_precipitation			TAG_Byte		Determines whether or not the biome has precipitation.		1: true, 0: false.
depth			Optional TAG_Float		The depth factor of the biome.		The default values vary between 1.5 and -1.8.
temperature			TAG_Float		The temperature factor of the biome.		The default values vary between 2.0 and -0.5.
scale			Optional TAG_Float		?		The default values vary between 1.225 and 0.0.
downfall			TAG_Float		?		The default values vary between 1.0 and 0.0.
category			Optional TAG_String		The category of the biome.		Known values are "ocean", "plains", "desert", "forest", "extreme_hills", "taiga", "swamp", "river", "nether", "the_end", "icy", "mushroom", "beach", "jungle", "mesa", "savanna", and "none".
temperature_modifier			Optional TAG_String		?		The only known value is "frozen".
effects	sky_color		TAG_Compound	TAG_Int	The color of the sky.		Example: 8364543, which is #7FA1FF in RGB.
	water_fog_color			TAG_Int	Possibly the tint color when swimming.		Example: 8364543, which is #7FA1FF in RGB.
	fog_color			TAG_Int	Possibly the color of the fog effect when looking past the view distance.		Example: 8364543, which is #7FA1FF in RGB.
	water_color			TAG_Int	The tint color of the water blocks.		Example: 8364543, which is #7FA1FF in RGB.
	foliage_color			Optional TAG_Int	The tint color of the grass.		Example: 8364543, which is #7FA1FF in RGB.
	grass_color			Optional TAG_Int	?		Example: 8364543, which is #7FA1FF in RGB.
	grass_color_modifier			Optional TAG_String	Unknown, likely affects foliage color.		If set, known values are "swamp" and "dark_forest".
	music			Optional TAG_Compound	Music properties for the biome.		If present, contains the fields: replace_current_music (TAG_Byte), sound (TAG_String), max_delay (TAG_Int), min_delay (TAG_Int).
	ambient_sound			Optional TAG_String	Ambient soundtrack.		If present, the ID of a soundtrack. Example: "minecraft:ambient.basalt_deltas.loop".
	additions_sound			Optional TAG_Compound	Additional ambient sound that plays randomly.		If present, contains the fields: sound (TAG_String), tick_chance (TAG_Double).
	mood_sound			Optional TAG_Compound	Additional ambient sound that plays at an interval.		If present, contains the fields: sound (TAG_String), tick_delay (TAG_Int), offset (TAG_Double), block_search_extent (TAG_Int).
	particle	probability	Optional TAG_Compound	TAG_FLOAT	Particles that appear randomly in the biome.	Possibly the probability of spawning the particle.	?
		options		TAG_COMPOUND		The properties of the particle to spawn.	Contains the field "type" (TAG_String), which identifies the particle type.

Chat Type

The minecraft:chat_type registry. <add some explanation here>

Chat type "chat" and "narration":

Name	Type	Notes
translation_key	TAG_String
style	TAG_Compound	Similar to Chat JSON (only present in "chat" TAG_Compound)
parameters	TAG_List of TAG_String	Values can be "sender", "target" and "content"

Damage Type

The minecraft:damage_type registry.

Dimension Type

The minecraft:dimension_type registry. It defines the types of dimension that can be attributed to a world, along with all their characteristics.

Dimension type:

Name	Type	Meaning		Values
piglin_safe	TAG_Byte	Whether piglins shake and transform to zombified piglins.		1: true, 0: false.
has_raids	TAG_Byte	Whether players with the Bad Omen effect can cause a raid.		1: true, 0: false.
monster_spawn_light_level	TAG_Int or TAG_Compound	Possibly the light level(s) at which monsters can spawn.	When TAG_Int, 0 - 15. When TAG_Compound, contains the fields: type (TAG_String), appears to be always "minecraft:uniform", and value (TAG_Compound), which contains the fields: max_inclusive (TAG_Int), min_inclusive (TAG_Int).
monster_spawn_block_light_limit	TAG_Int
natural	TAG_Byte	When false, compasses spin randomly. When true, nether portals can spawn zombified piglins.		1: true, 0: false.
ambient_light	TAG_Float	How much light the dimension has.		0.0 to 1.0.
fixed_time	Optional TAG_Long	If set, the time of the day is the specified value.		If set, 0 to 24000.
infiniburn	TAG_String	A resource location defining what block tag to use for infiniburn.		"#" or minecraft resource "#minecraft:...".
respawn_anchor_works	TAG_Byte	Whether players can charge and use respawn anchors.		1: true, 0: false.
has_skylight	TAG_Byte	Whether the dimension has skylight access or not.		1: true, 0: false.
bed_works	TAG_Byte	Whether players can use a bed to sleep.		1: true, 0: false.
effects	TAG_String	?		"minecraft:overworld", "minecraft:the_nether", "minecraft:the_end" or something else.
min_y	TAG_Int	The minimum Y level.		A multiple of 16. Example: -64
height	TAG_Int	The maximum height.		A multiple of 16. Example: 256
logical_height	TAG_Int	The maximum height to which chorus fruits and nether portals can bring players within this dimension. (Must be lower than height)		0-384.
coordinate_scale	TAG_Double	The multiplier applied to coordinates when traveling to the dimension.		0.00001 - 30000000.0
ultrawarm	TAG_Byte	Whether the dimensions behaves like the nether (water evaporates and sponges dry) or not. Also causes lava to spread thinner.		1: true, 0: false.
has_ceiling	TAG_Byte	Whether the dimension has a bedrock ceiling or not. When true, causes lava to spread faster.		1: true, 0: false.

Default Registries

The default registries in the JSON format is available for the following versions:

• 1.20.1
• 1.19.2
• 1.19