Pre-release protocol

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Revision as of 18:45, 18 April 2018 by Pokechu22 (talk | contribs) (→‎Entity Metadata Format: New entity metadata)
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This page documents the changes from the last stable Minecraft release (currently 1.12.2, protocol 340) to the current pre-release (currently 18w15a, protocol 371). Note that this page contains bleeding-edge information that may not be completely or correctly documented.

One who wishes to commandeer the merging of this into Protocol when an update is made must be sure to respect any changes that may have occurred to the respective packets there.

Contents

Data types

Other definitions

Global palette

A table/dictionary/palette mapping nonnegative integers to block states. The block state IDs can be constructed from this table by multiplying what the Minecraft Wiki calls “block IDs” by 16 and adding the metadata/damage value (or in most programming languages block_id << 4 | metadata). Block state IDs are created in a linear fashion based off of order of assignment. One block state ID allocated for each unique block state for a block; if a block has multiple properties then the number of allocated states is the product of the number of values for each property. A current list of properties and state ID ranges is found on burger.

Alternatively, the vanilla server now includes an option to export the current block state ID mapping, by running java -cp minecraft_server.18w15a.jar net.minecraft.data.Main --reports (use --help for a list of other options). One can parse the generated blocks.json to convert known block states to and from ids.

Packets

ID Packet name Documentation
Handshaking serverbound
0x00 Handshake Current Pre
Play clientbound
0x04 Spawn Painting Current Pre
0x07 Statistics Current Pre
0x09 Update Block Entity Current Pre
0x0B Block Change Current Pre
0x0F 0x0E Chat Message (clientbound) Current (unchanged)
0x10 0x0F Multi Block Change Current Pre
0x0E 0x10 Tab-Complete (clientbound) Current Pre
0x11 Declare Commands Pre
0x11 0x12 Confirm Transaction (clientbound) Current (unchanged)
0x12 0x13 Close Window (clientbound) Current (unchanged)
0x13 0x14 Open Window Current (unchanged)
0x14 0x15 Window Items Current (unchanged)
0x15 0x16 Window Property Current (unchanged)
0x16 0x17 Set Slot Current (unchanged)
0x17 0x18 Set Cooldown Current (unchanged)
0x18 0x19 Plugin Message (clientbound) Current (unchanged)
0x19 0x1A Named Sound Effect Current Pre
0x1A 0x1B Disconnect (play) Current (unchanged)
0x1B 0x1C Entity Status Current (unchanged)
0x1C 0x1D Explosion Current (unchanged)
0x1D 0x1E Unload Chunk Current (unchanged)
0x1E 0x1F Change Game State Current (unchanged)
0x1F 0x20 Keep Alive (clientbound) Current (unchanged)
0x20 0x21 Chunk Data Current Pre
0x21 0x22 Effect Current (unchanged)
0x22 0x23 Spawn Particle Current Pre
0x23 0x24 Join Game Current (unchanged)
0x24 0x25 Map Current Pre
0x25 0x26 Entity Current (unchanged)
0x26 0x27 Entity Relative Move Current (unchanged)
0x27 0x28 Entity Look And Relative Move Current (unchanged)
0x28 0x29 Entity Look Current (unchanged)
0x29 0x2A Vehicle Move (clientbound) Current (unchanged)
0x2A 0x2B Open Sign Editor Current (unchanged)
0x2B 0x2C Craft Recipe Response Current Pre
0x2C 0x2D Player Abilities (clientbound) Current (unchanged)
0x2D 0x2E Combat Event Current (unchanged)
0x2E 0x2F Player List Item Current (unchanged)
0x30 Face Player Pre
0x2F 0x31 Player Position And Look (clientbound) Current (unchanged)
0x30 0x32 Use Bed Current (unchanged)
0x31 0x33 Unlock Recipes Current Pre
0x32 0x34 Destroy Entities Current (unchanged)
0x33 0x35 Remove Entity Effect Current (unchanged)
0x34 0x36 Resource Pack Send Current (unchanged)
0x35 0x37 Respawn Current (unchanged)
0x36 0x38 Entity Head Look Current (unchanged)
0x37 0x39 Select Advancement Tab Current (unchanged)
0x38 0x3A World Border Current (unchanged)
0x39 0x3B Camera Current (unchanged)
0x3A 0x3C Held Item Change (clientbound) Current (unchanged)
0x3B 0x3D Display Scoreboard Current (unchanged)
0x3C 0x3E Entity Metadata Current (unchanged)
0x3D 0x3F Attach Entity Current (unchanged)
0x3E 0x40 Entity Velocity Current (unchanged)
0x3F 0x41 Entity Equipment Current (unchanged)
0x40 0x42 Set Experience Current (unchanged)
0x41 0x43 Update Health Current (unchanged)
0x42 0x44 Scoreboard Objective Current Pre
0x43 0x45 Set Passengers Current (unchanged)
0x44 0x46 Teams Current Pre
0x45 0x47 Update Score Current (unchanged)
0x46 0x48 Spawn Position Current (unchanged)
0x47 0x49 Time Update Current (unchanged)
0x48 0x4A Title Current (unchanged)
0x4B Stop Sound Pre
0x49 0x4C Sound Effect Current (unchanged)
0x4A 0x4D Player List Header And Footer Current (unchanged)
0x4B 0x4E Collect Item Current (unchanged)
0x4C 0x4F Entity Teleport Current (unchanged)
0x4D 0x50 Advancements Current (unchanged)
0x4E 0x51 Entity Properties Current (unchanged)
0x4F 0x52 Entity Effect Current (unchanged)
0x53 Declare Recipes Pre
0x54 Tags Pre
Play serverbound
0x02 0x01 Chat Message (serverbound) Current (unchanged)
0x03 0x02 Client Status Current (unchanged)
0x04 0x03 Client Settings Current (unchanged)
0x01 0x04 Tab-Complete (serverbound) Current Pre
0x12 Craft Recipe Request Current Pre
0x17 Recipe Book Data Current Pre

New/modified data types

Slot

Name Type Meaning
Block ID Item ID Short The item/block ID. A value of -1 signifies that the slot is empty, and no further data follows. Item IDs are now uniquely defined and are completely independent of block IDs.
Item Count Optional Byte Not present if Block ID is -1.
Item Damage Optional Short Not present if Block ID is -1.
NBT Optional NBT Not present if Block ID is -1. If 0, there is no NBT data, and no further data follows. Otherwise the byte is the start of an NBT blob as shown below:

Particle

Field Name Field Type Meaning
ID VarInt The ID of the particle type, see below.
Data Varies Varies based on the particle type, see below.
Particle Name Particle ID Data
minecraft:ambient_entity_effect 0 None
minecraft:angry_villager 1 None
minecraft:barrier 2 None
minecraft:block 3
Field Name Field Type Meaning
BlockState VarInt The ID of the block state.
minecraft:bubble 4 None
minecraft:cloud 5 None
minecraft:crit 6 None
minecraft:damage_indicator 7 None
minecraft:dragon_breath 8 None
minecraft:dripping_lava 9 None
minecraft:dripping_water 10 None
minecraft:dust 11
Field Name Field Type Meaning
Red Float Red value, 0-1
Green Float Green value, 0-1
Blue Float Blue value, 0-1
Scale Float The scale, will be clamped between 0.01 and 4.
minecraft:effect 12 None
minecraft:elder_guardian 13 None
minecraft:enchanted_hit 14 None
minecraft:enchant 15 None
minecraft:end_rod 16 None
minecraft:entity_effect 17 None
minecraft:explosion_emitter 18 None
minecraft:explosion 19 None
minecraft:falling_dust 20
Field Name Field Type Meaning
BlockState VarInt The ID of the block state.
minecraft:firework 21 None
minecraft:fishing 22 None
minecraft:flame 23 None
minecraft:happy_villager 24 None
minecraft:heart 25 None
minecraft:instant_effect 26 None
minecraft:item 27
Field Name Field Type Meaning
Item Slot The item that will be used.
minecraft:item_slime 28 None
minecraft:item_snowball 29 None
minecraft:large_smoke 30 None
minecraft:lava 31 None
minecraft:mycelium 32 None
minecraft:note 33 None
minecraft:poof 34 None
minecraft:portal 35 None
minecraft:rain 36 None
minecraft:smoke 37 None
minecraft:spit 38 None
minecraft:squid_ink 39 None
minecraft:sweep_attack 40 None
minecraft:totem_of_undying 41 None
minecraft:underwater 42 None
minecraft:splash 43 None
minecraft:witch 44 None
minecraft:bubble_pop 45 None
minecraft:current_down 46 None
minecraft:bubble_column_up 47 None

Entity Metadata Format

Note that entity metadata is a totally distinct concept from block metadata. It is not required to send all metadata fields, or even any metadata fields, so long as the terminating entry is correctly sent.

Entity Metadata is an array of entries, each of which looks like the following:

Name Type Meaning
Index Unsigned Byte Unique index key determining the meaning of the following value, see the table below. If this is 0xff then the it is the end of the Entity Metadata array and no more is read.
Type Optional Byte Enum Only if Index is not 0xff; the type of the index, see the table below
Value Optional value of Type Only if Index is not 0xff: the value of the metadata field
Value of Type field Type of Value field Notes
0 Byte
1 VarInt
2 Float
3 String
4 Chat
5 OptChat (Boolean + Optional Chat) Chat is present if the Boolean is set to true
5 6 Slot
6 7 Boolean
7 8 Rotation 3 floats: rotation on x, rotation on y, rotation on z
8 9 Position
9 10 OptPosition (Boolean + Optional Position) Position is present if the Boolean is set to true
10 11 Direction (VarInt) (Down = 0, Up = 1, North = 2, South = 3, West = 4, East = 5)
11 12 OptUUID (Boolean + Optional UUID) UUID is present if the Boolean is set to true
12 13 OptBlockID (VarInt) 0 for absent, otherwise index into the global palette. (Air is treated as absent)
13 14 NBT Tag
15 #Particle

Entity

The base class.

Index Type Meaning Default
0 Byte Bit mask Meaning 0
0x01 On Fire
0x02 Crouched
0x04 Unused (previously riding)
0x08 Sprinting
0x10 Unused (previously eating/drinking/blocking; use hand state now)
0x20 Invisible
0x40 Glowing effect
0x80 Flying with elytra
1 VarInt Air 300
2 String OptChat Custom name empty
3 Boolean Is custom name visible false
4 Boolean Is silent false
5 Boolean No gravity false

AreaEffectCloud

Extends Entity.

Index Type Meaning Default
6 Float Radius 0.5
7 VarInt Color (only for mob spell particle) 0
8 Boolean Ignore radius and show effect as single point, not area false
9 Particle The #Particle effect
9 VarInt Particle ID 15 (mobSpell)
10 VarInt Particle parameter 1 0
11 VarInt Particle parameter 2 0

Trident

Extends Arrow.

Index Type Meaning Default
7 VarInt Loyalty level (enchantment) 0

Boat

Extends Entity.

Index Type Meaning Default
6 VarInt Time since last hit 0
7 VarInt Forward direction 1
8 Float Damage taken 0.0
9 VarInt Type (0=oak, 1=spruce, 2=birch, 3=jungle, 4=acacia, 5=dark oak) 0
10 Boolean Right paddle turning false
11 Boolean Left paddle turning false
12 VarInt Splash timer (?) 0

Phantom

Extends Flying.

Index Type Meaning Default
12 VarInt Size 0

Hitbox size is determined by horizontal=0.9 + 0.2*size and vertical=0.5 + 0.1 * i

Dolphin

Extends Creature.

No additional metadata.

WaterMob

Extends Insentient Creature.

No additional metadata.

Abstract fish

Extends WaterMob.

Index Type Meaning Default
12 Boolean From bucket False

Cod

Extends AbstractFish.

No additional metadata.

Puffer fish

Extends AbstractFish.

Index Type Meaning Default
13 VarInt PuffState (varies from 0 to 2) 0

Salmon

Extends AbstractFish.

No additional metadata.

Tropical fish

Extends AbstractFish.

Index Type Meaning Default
13 VarInt Variant 0

Turtle

Extends Animal.

Index Type Meaning Default
13 BlockPos Home pos (0, 0, 0)
14 Boolean Has egg false
15 Boolean Laying egg (?) false
16 BlockPos Travel pos (0, 0, 0)
17 Boolean Going home false
18 Boolean Traveling false

Drowned

Extends Drowned.

Index Type Meaning Default
15 Boolean Has target (?) false

Block Actions

No changes so far.

Plugin Channels

MC|StopSound

Server to client

Used to implement the /stopsound command. Stops a sound that is currently playing on the client.

Field name Field type Notes
Sound category String Should be one of the sound categories used in Named Sound Effect, but if it's invalid or empty then it is (intentionally) treated as all sound categories.
Sound name String A sound effect name. If left empty, all sounds are stopped.

Emptiness of sound category or sound name can be combined, IE a empty sound name but a set sound category will stop all sounds in the given category.

This plugin channel has been replaced by the stop sound packet.

MC|DebugCaves

Never sent, but (presumably) used to debug caves. Does not render without modifying the client.

Field name Field type Notes
Unknown 1 Position
Count Int Number of elements in the following array
Data Unknown 2 Array Position
Unknown 3 Float

MC|DebugStructures

Never sent, but (presumably) used to debug structures. Does not render without modifying the client.

Field name Field type Notes
Unknown 1 Int
Bounding box minX Int min must be less than max
Bounding box minY Int
Bounding box minZ Int
Bounding box maxX Int
Bounding box maxY Int
Bounding box maxZ Int
Count Int Number of elements in the following array
Unknown Bounding box minX Array Int min must be less than max
Bounding box minY Int
Bounding box minZ Int
Bounding box maxX Int
Bounding box maxY Int
Bounding box maxZ Int
Unknown Boolean

MC|DebugWorldGenAttempt

Never sent, but (presumably) used to debug something with world generation. Does not render without modifying the client.

Warning.png This channel is invalid, as its name is longer than the max length (23 > 20).

Field name Field type Notes
Unknown 1 Position
Unknown 2 Float
Unknown 3 Float
Unknown 4 Float
Unknown 5 Float
Unknown 6 Float

Play

Clientbound

Spawn Painting

This packet shows location, name, and type of painting.

Packet ID State Bound To Field Name Field Type Notes
0x04 Play Client Entity ID VarInt
Entity UUID UUID
Motive String (13) VarInt Name of the painting. Max length 13 Panting's ID, see below
Location Position Center coordinates (see below)
Direction Byte Enum Direction the painting faces (North = 2, South = 0, West = 1, East = 3)

Calculating the center of an image: given a (width × height) grid of cells, with (0, 0) being the top left corner, the center is (max(0, width / 2 - 1), height / 2). E.g. (1, 0) for a 2×1 painting, or (1, 2) for a 4×4 painting.

List of paintings by coordinates in paintings_kristoffer_zetterstrand.png (where x and y are in pixels from the top left and width and height are in pixels or 16ths of a block):

Name ID x y width height
Kebab minecraft:kebab 0 0 0 16 16
Aztec minecraft:aztec 1 16 0 16 16
Alban minecraft:alban 2 32 0 16 16
Aztec2 minecraft:aztec2 3 48 0 16 16
Bomb minecraft:bomb 4 64 0 16 16
Plant minecraft:plant 5 80 0 16 16
Wasteland minecraft:wasteland 6 96 0 16 16
Pool minecraft:pool 7 0 32 32 16
Courbet minecraft:courbet 8 32 32 32 16
Sea minecraft:sea 9 64 32 32 16
Sunset minecraft:sunset 10 96 32 32 16
Creebet minecraft:creebet 11 128 32 32 16
Wanderer minecraft:wanderer 12 0 64 16 32
Graham minecraft:graham 13 16 64 16 32
Match minecraft:match 14 0 128 32 32
Bust minecraft:bust 15 32 128 32 32
Stage minecraft:stage 16 64 128 32 32
Void minecraft:void 17 96 128 32 32
SkullAndRoses skull_and_roses 18 128 128 32 32
Wither minecraft:wither 19 160 128 32 32
Fighters minecraft:fighters 20 0 96 64 32
Pointer minecraft:pointer 21 0 192 64 64
Pigscene minecraft:pigscene 22 64 192 64 64
BurningSkull minecraft:burning_skull 23 128 192 64 64
Skeleton minecraft:skeleton 24 192 64 64 48
DonkeyKong minecraft:donkey_kong 25 192 112 64 48

The Minecraft Wiki article on paintings also provides a list of painting names to the actual images.

Statistics

Sent as a response to Client Status (id 1).

Packet ID State Bound To Field Name Field Type Notes
0x07 Play Client Count VarInt Number of elements in the following array
Statistic Name Array String (32767) https://gist.github.com/Alvin-LB/8d0d13db00b3c00fd0e822a562025eff
Category ID VarInt See below
Statistic ID VarInt See below
Value VarInt The amount to set it to

Categories (these are namespaced, but with :. replaced with .):

Name ID Registry
minecraft.mined 0 Blocks
minecraft.crafted 1 Items
minecraft.used 2 Items
minecraft.broken 3 Items
minecraft.picked_up 4 Items
minecraft.dropped 5 Items
minecraft.killed 6 Entities
minecraft.killed_by 7 Entities
minecraft.custom 8 Custom

Blocks, Items, and Entities use block (not block state), item, and entity ids.

Custom has the following (unit only matters for clients):

Name ID Unit
minecraft.leave_game 0 None
minecraft.play_one_minute 1 Time
minecraft.time_since_death 2 Time
minecraft.sneak_Time 3 Time
minecraft.walk_one_cm 4 Distance
minecraft.crouch_one_cm 5 Distance
minecraft.sprint_one_cm 6 Distance
minecraft.swim_one_cm 7 Distance
minecraft.fall_one_cm 8 Distance
minecraft.climb_one_cm 9 Distance
minecraft.fly_one_cm 10 Distance
minecraft.dive_one_cm 11 Distance
minecraft.minecart_one_cm 12 Distance
minecraft.boat_one_cm 13 Distance
minecraft.pig_one_cm 14 Distance
minecraft.horse_one_cm 15 Distance
minecraft.aviate_one_cm 16 Distance
minecraft.jump 17 None
minecraft.drop 18 None
minecraft.damage_dealt 19 Damage
minecraft.damage_taken 20 Damage
minecraft.deaths 21 None
minecraft.mob_kills 22 None
minecraft.animals_bred 23 None
minecraft.player_kills 24 None
minecraft.fish_caught 25 None
minecraft.talked_to_villager 26 None
minecraft.traded_with_villager 27 None
minecraft.eat_cake_slice 28 None
minecraft.fill_cauldron 29 None
minecraft.use_cauldron 30 None
minecraft.clean_armor 31 None
minecraft.clean_banner 32 None
minecraft.interact_with_brewingstand 33 None
minecraft.interact_with_beacon 34 None
minecraft.inspect_dropper 35 None
minecraft.inspect_hopper 36 None
minecraft.inspect_dispenser 37 None
minecraft.play_noteblock 38 None
minecraft.tune_noteblock 39 None
minecraft.pot_flower 40 None
minecraft.trigger_trapped_chest 41 None
minecraft.open_enderchest 42 None
minecraft.enchant_item 43 None
minecraft.play_record 44 None
minecraft.interact_with_furnace 45 None
minecraft.interact_with_crafting_table 46 None
minecraft.open_chest 47 None
minecraft.sleep_in_bed 48 None
minecraft.open_shulker_box 49 None

Units:

  • None: just a normal number (formatted with 0 decimal places)
  • Damage: value is 10 times the normal amount
  • Distance: a distance in centimeters (hundredths of blocks)
  • Time: a time span in ticks

Update Block Entity

Sets tile entity associated with the block at the given location.

Packet ID State Bound To Field Name Field Type Notes
0x09 Play Client Location Position
Action Unsigned Byte The type of update to perform, see below
NBT Data NBT Tag Data to set. May be a TAG_END (0), in which case the block entity at the given location is removed (though this is not required since the client will remove the block entity automatically on chunk unload or block removal)

Action field:

  • 1: Set data of a mob spawner (everything except for SpawnPotentials: current delay, min/max delay, mob to be spawned, spawn count, spawn range, etc.)
  • 2: Set command block text (command and last execution status)
  • 3: Set the level, primary, and secondary powers of a beacon
  • 4: Set rotation and skin of mob head
  • 5: Set type of flower in flower pot
  • 5: Declare a conduit
  • 6: Set base color and patterns on a banner
  • 7: Set the data for a Structure tile entity
  • 8: Set the destination for a end gateway
  • 9: Set the text on a sign
  • 10: Declare a shulker box, no data appears to be sent and the client seems to do fine without this packet. Perhaps it is a leftover from earlier versions?
  • 11: Set the color of a bed Declare a bed

Block Change

Fired whenever a block is changed within the render distance.

Warning.png Changing a block in a chunk that is not loaded is not a stable action. The Notchian client currently uses a shared empty chunk which is modified for all block changes in unloaded chunks; while in 1.9 this chunk never renders in older versions the changed block will appear in all copies of the empty chunk. Servers should avoid sending block changes in unloaded chunks and clients should ignore such packets.

Packet ID State Bound To Field Name Field Type Notes
0x0B Play Client Location Position Block Coordinates
Block ID VarInt The new block state ID for the block as given in the global palette. (When reading data: type = id >> 4, meta = id & 15, when writing data: id = type << 4 | (meta & 15)) See that section for more information.

Multi Block Change

Fired whenever 2 or more blocks are changed within the same chunk on the same tick.

Warning.png Changing blocks in chunks not loaded by the client is unsafe (see note on Block Change).

Packet ID State Bound To Field Name Field Type Notes
0x10 0x0F Play Client Chunk X Int Chunk X coordinate
Chunk Z Int Chunk Z coordinate
Record Count VarInt Number of elements in the following array, i.e. the number of blocks affected
Record Horizontal Position Array Unsigned Byte The 4 most significant bits (0xF0) encode the X coordinate, relative to the chunk. The 4 least significant bits (0x0F) encode the Z coordinate, relative to the chunk.
Y Coordinate Unsigned Byte Y coordinate of the block
Block ID VarInt The new block state ID for the block as given in the global palette. (When reading data: type = id >> 4, meta = id & 15, when writing data: id = type << 4 | (meta & 15)) See that section for more information.

To decode the position into a world position:

worldX = (horizPos >> 4 & 15) + (chunkX * 16);
worldY = vertPos;
worldZ = (horizPos & 15) + (chunkZ * 16);


Tab-Complete (clientbound)

Used to respond to the client's previous tab complete request.

Packet ID State Bound To Field Name Field Type Notes
0x0E 0x10 Play Client Transaction Id VarInt This id should also be used in the tab completion response packet, or it will be ignored.
Start VarInt Start of the text to replace
Length VarInt Length of the text to replace
Count VarInt Number of elements in the following array
Matches Match Array String (32767) One eligible command value to insert, note that each command is sent separately instead of in a single string, hence the need for Count. Note that for instance this doesn't include a leading / on commands.
Has tooltip Boolean True if the following is present
Tooltip Optional Chat Tooltip to display; only present if previous Boolean is true

Declare Commands

Lists all of the commands on the server, and how they are parsed.

This is a tree, with one root node. Each redirect or child node must refer only to nodes that have already been declared.

Packet ID State Bound To Field Name Field Type Notes
0x11 Play Client Count VarInt Number of elements in the following array
Nodes Array of Node A array of CommandNodes
Root index VarInt Index of the RootCommandNode in the previous array

Node:

Field Name Field Type Notes
Flags Byte
Bit mask Meaning
0x03 Type of the CommandNode
0 RootCommandNode
1 LiteralCommandNode
2 ArgumentCommandNode
0x04 Has command
0x08 Has redirect node
0x10 Has custom suggestions, currently only present if the type is a ArgumentCommandNode
Children Count VarInt Number of elements in the following array
Children Array of VarInt The indexes of the children CommandNodes within the Nodes array
Redirect node Optional VarInt Only if flags & 0x08. Points to the redirect CommandNode within the Nodes array
Extra node data Extra node data Type depends on the CommandNode type, see below.

Extra node data:

Type Field Name Field Type Notes
RootCommandNode Empty Empty
LiteralCommandNode Literal String (32767) The text
ArgumentCommandNode Name String (32767) The name of the argument
Parser Identifier One of several known to the client, listed below. If the client does not know the parser, reading this RequiredArgumentBuilder stops immediately (following fields are not read)
Properties Optional, varies See below. Varies depending on the parser.
Suggests Optional Identifier Only present if (flags & 0x10) != 0. See below for the available types.

Parsers:

Identifier Description Properties
brigadier:bool Boolean value (true or false, case-sensitive) None
brigadier:double Double Specifies min and max values:
Name Type Description
Flags Byte
Min Optional double Only if flags & 0x01. If not specified, defaults to -Double.MAX_VALUE (≈ -1.7976931348623157E307)
Max Optional double Only if flags & 0x02. If not specified, defaults to Double.MAX_VALUE (≈ 1.7976931348623157E307)
brigadier:float Float Specifies min and max values:
Name Type Description
Flags Byte
Min Optional float Only if flags & 0x01. If not specified, defaults to -Float.MAX_VALUE (≈ -3.4028235E38)
Max Optional float Only if flags & 0x02. If not specified, defaults to Float.MAX_VALUE (≈ 3.4028235E38)
brigadier:integer Integer Specifies min and max values:
Name Type Description
Flags Byte
Min Optional integer Only if flags & 0x01. If not specified, defaults to Integer.MIN_VALUE (-2147483648)
Max Optional integer Only if flags & 0x02. If not specified, defaults to Integer.MAX_VALUE (2147483647)
brigadier:string A string A VarInt enum:
Value Name Description
0 SINGLE_WORD Reads a single word
1 QUOTABLE_PHRASE If it starts with a ", keeps reading until another " (allowing escaping with \). Otherwise behaves the same as SINGLE_WORD
2 GREEDY_PHRASE Reads the rest of the content after the cursor. Quotes will not be removed.
minecraft:entity A selector, player name, or UUID. Has a single flags byte:
Bit mask Meaning
0x01 If set, only allows a single entity/player
0x02 If set, only allows players
minecraft:game_profile A player, online or not. Can also use a selector, which may match one or more players (but not entities). None
minecraft:block_pos A location, represented as 3 numbers (which must be integers). May use relative locations with ~. None
minecraft:vec3 A location, represented as 3 numbers (which may have a decimal point, but will be moved to the center of a block if none is specified). May use relative locations with ~. None
minecraft:vec2 A location, represented as 2 numbers (which may have a decimal point, but will be moved to the center of a block if none is specified). May use relative locations with ~. None
minecraft:block_state A block state, optionally including NBT and state information. None
minecraft:block_predicate A block, or a block tag. None
minecraft:item_stack An item, optionally including NBT. None
minecraft:item_predicate An item, or an item tag. None
minecraft:color A chat color. One of the names from Chat#Colors, or reset. Case-insensitive. None
minecraft:component A JSON Chat component. None
minecraft:message A regular message, potentially including selectors. None
minecraft:nbt An NBT value, parsed using JSON-NBT rules. None
minecraft:nbt_path A path within an NBT value, allowing for array and member accesses. None
minecraft:objective A scoreboard objective. None
minecraft:objective_criteria A single score criterion. None
minecraft:operation A scoreboard operator. None
minecraft:particle A particle effect (an identifier with extra information following it for specific particles, mirroring the Particle packet) None
minecraft:rotation An angle, represented as 2 numbers (which may have a decimal point, but will be moved to the center of a block if none is specified). May use relative locations with ~. None
minecraft:scoreboard_slot A scoreboard display position slot. list, sidebar, belowName, and sidebar.team.${color} for all chat colors (reset is not included) None
minecraft:score_holder Something that can join a team. Allows selectors and *. Has a single flags byte:
Bit mask Meaning
0x01 If set, allows multiple.
minecraft:swizzle A collection of up to 3 axes. None
minecraft:team The name of a team. Parsed as an unquoted string. None
minecraft:item_slot A name for an inventory slot. None
minecraft:resource_location An Identifier. None
minecraft:mob_effect A potion effect. None
minecraft:function A function. None
minecraft:entity_anchor The entity anchor related to the facing argument in the teleport command, is feet or eyes. None
minecraft:range A range of values with a min and a max.
Name Type Description
Decimals Boolean Whether decimal values are allowed.
minecraft:item_enchantment Represents a item enchantment. None

Suggestion types:

Identifier Description
minecraft:ask_server Sends the Tab-Complete packet to the server to request tab completions.
minecraft:all_recipes Suggests all the available recipes.
minecraft:available_sounds Suggests all the available sounds.
minecraft:summonable_entities Suggests all the summonable entities.

Named Sound Effect

See also: #Sound Effect

Used to play a sound effect on the client. Custom sounds may be added by resource packs.

Packet ID State Bound To Field Name Field Type Notes
0x19 0x1A Play Client Sound Name String (256) Identifier All sound effect names as of 1.12.2 can be seen here.
Sound Category VarInt Enum The category that this sound will be played from (current categories)
Effect Position X Int Effect X multiplied by 8 (fixed-point number with only 3 bits dedicated to the fractional part)
Effect Position Y Int Effect Y multiplied by 8 (fixed-point number with only 3 bits dedicated to the fractional part)
Effect Position Z Int Effect Z multiplied by 8 (fixed-point number with only 3 bits dedicated to the fractional part)
Volume Float 1 is 100%, can be more
Pitch Float Float between 0.5 and 2.0 by Notchian clients

Chunk Data

Main article: Chunk Format
See also: #Unload Chunk

The server only sends skylight information for chunk pillars in the Overworld, it's up to the client to know in which dimenison the player is currently located. You can also infer this information from the primary bitmask and the amount of uncompressed bytes sent. This packet also sends all block entities in the chunk (though sending them is not required; it is still legal to send them with Update Block Entity later).

Indexes into the global palette are still used, but since the global palette has changed, behavior is different.

The bits per block value used to index in the global palette is 13 14, which is determined by taking the base 2 logarithm of the highest state ID and then rounding up (or alternatively, simply checking how many bits are needed to represent the highest state ID).

Packet ID State Bound To Field Name Field Type Notes
0x20 0x21 Play Client Chunk X Int Chunk coordinate (block coordinate divided by 16, rounded down)
Chunk Z Int Chunk coordinate (block coordinate divided by 16, rounded down)
Ground-Up Continuous Boolean See Chunk Format
Primary Bit Mask VarInt Bitmask with bits set to 1 for every 16×16×16 chunk section whose data is included in Data. The least significant bit represents the chunk section at the bottom of the chunk column (from y=0 to y=15).
Size VarInt Size of Data in bytes
Data Byte array See data structure in Chunk Format
Number of block entities VarInt Number of elements in the following array
Block entities Array of NBT Tag All block entities in the chunk. Use the x, y, and z tags in the NBT to determine their positions.
Data structure

The data section of the packet contains most of the useful data for the chunk.

Field Name Field Type Notes
Data Array of Chunk Section The number of elements is equal to the number of bits set in Primary Bit Mask. Sections are sent bottom-to-top, i.e. the first section, if sent, extends from Y=0 to Y=15.
Biomes Optional Byte Int Array Only sent if Ground-Up Continuous is true; 256 bytes entries if present

Spawn Particle

Displays the named particle

Packet ID State Bound To Field Name Field Type Notes
0x22 0x23 Play Client Particle ID Int The particle ID listed in #Particle.
Long Distance Boolean If true, particle distance increases from 256 to 65536
X Float X position of the particle
Y Float Y position of the particle
Z Float Z position of the particle
Offset X Float This is added to the X position after being multiplied by random.nextGaussian()
Offset Y Float This is added to the Y position after being multiplied by random.nextGaussian()
Offset Z Float This is added to the Z position after being multiplied by random.nextGaussian()
Particle Data Float The data of each particle
Particle Count Int The number of particles to create
Data Array of VarInt Varies Length depends on particle. "iconcrack" has length of 2, "blockcrack", "blockdust", and "fallingdust" have lengths of 1, the rest have 0. The variable data listed in #Particle

Map

Updates a rectangular area on a map item.

Warning.png Map icons with types over 15 currently don't work on servers (see MC-126815).

Packet ID State Bound To Field Name Field Type Notes
0x24 0x25 Play Client Item Damage VarInt The damage value (map ID) of the map being modified
Scale Byte From 0 for a fully zoomed-in map (1 block per pixel) to 4 for a fully zoomed-out map (16 blocks per pixel)
Tracking Position Boolean Specifies whether the icons are shown
Icon Count VarInt Number of elements in the following array
Icon Direction And Type Array Byte 0xF0 = Type, 0x0F = Direction
X Byte
Z Byte
Has Display Name Boolean
Display Name Optional Chat Only present if previous Boolean is true
Columns Byte Number of columns updated
Rows Optional Byte Only if Columns is more than 0; number of rows updated
X Optional Byte Only if Columns is more than 0; x offset of the westernmost column
Z Optional Byte Only if Columns is more than 0; z offset of the northernmost row
Length Optional VarInt Only if Columns is more than 0; length of the following array
Data Optional Array of Unsigned Byte Only if Columns is more than 0; see Map item format

For icons, a direction of 0 is a vertical icon and increments by 22.5° (360/16).

Types are based off of rows and columns in map_icons.png:

Icon type Result
0 White arrow (players)
1 Green arrow (item frames)
2 Red arrow
3 Blue arrow
4 White cross
5 Red pointer
6 White circle (off-map players)
7 Small white circle (far-off-map players)
8 Mansion
9 Temple
10 White Banner
11 Orange Banner
12 Magenta Banner
13 Light Blue Banner
14 Yellow Banner
15 Lime Banner
16 Pink Banner
17 Gray Banner
18 Light Gray Banner
19 Cyan Banner
20 Purple Banner
21 Blue Banner
22 Brown Banner
23 Green Banner
24 Red Banner
25 Black Banner
26 Treasure marker

Craft Recipe Response

Response to the serverbound packet (Craft Recipe Request), with the same recipe ID. Appears to be used to notify the UI.

Packet ID State Bound To Field Name Field Type Notes
0x2B 0x2C Play Client Window ID Byte
Recipe VarInt Identifer A recipe ID

Face Player

Used to rotate the client player to face the given location or entity (for /teleport [<targets>] <x> <y> <z> facing).

Packet ID State Bound To Field Name Field Type Notes
0x30 Play Client
Feet/eyes VarInt enum Values are feet=0, eyes=1. If set to eyes, aims using the head position; otherwise aims using the feet position.
Target x Double x coordinate of the point to face towards
Target y Double y coordinate of the point to face towards
Target z Double z coordinate of the point to face towards
Is entity Boolean If true, additional information about an entity is provided.
Entity ID Optional VarInt Only if is entity is true — the entity to face towards
Entity feet/eyes Optional VarInt enum Whether to look at the entity's eyes or feet. Same values and meanings as before, just for the entity's head/feet.

If the entity given by entity ID cannot be found, this packet should be treated as if is entity was false.

Unlock Recipes

Packet ID State Bound To Field Name Field Type Notes
0x31 0x33 Play Client
Action VarInt 0: init, 1: add, 2: remove
Crafting Recipe Book Open Boolean If true, then the crafting recipe book will be open when the player opens its inventory.
Crafting Recipe Book Filter Active Boolean If true, then the filtering option is active when the players opens its inventory.
Smelting Recipe Book Open Boolean If true, then the smelting recipe book will be open when the player opens its inventory.
Smelting Recipe Book Filter Active Boolean If true, then the filtering option is active when the players opens its inventory.
Array size 1 VarInt Number of elements in the following array
Recipe IDs Array of VarInt Identifier
Array size 2 Optional VarInt Number of elements in the following array, only present if mode is 0 (init)
Recipe IDs Optional Array of VarInt Identifier, only present if mode is 0 (init)

Action:

  • 0 (init) = All the recipes in the list 2 will added to the recipe book. All the recipes in list 1 will be tagged as displayed, recipes that aren't tagged will be shown in the notification. VERIFY LIST ORDER?
  • 1 (add) = All the recipes in the list are added and their icon will be shown in the notification.
  • 2 (remove) = Remove all the recipes in the list. This allows them to re-displayed when they are readded.

Scoreboard Objective

This is sent to the client when it should create a new scoreboard objective or remove one.

Packet ID State Bound To Field Name Field Type Notes
0x42 0x44 Play Client Objective Name String (16) An unique name for the objective
Mode Byte 0 to create the scoreboard. 1 to remove the scoreboard. 2 to update the display text.
Objective Value Optional String (32) Only if mode is 0 or 2. The text to be displayed for the score
Type Optional String VarInt Enum Only if mode is 0 or 2. “integer” or “hearts”

Teams

Creates and updates teams.

Packet ID State Bound To Field Name Field Type Notes
0x44 0x46 Play Client Team Name String (16) A unique name for the team. (Shared with scoreboard).
Mode Byte Determines the layout of the remaining packet
0: create team Team Display Name String (32)
Team Prefix String (16) Displayed before the names of players that are part of this team
Team Suffix String (16) Displayed after the names of players that are part of this team
Friendly Flags Byte Bit mask. 0x01: Allow friendly fire, 0x02: can see invisible players on same team
Name Tag Visibility String Enum (32) always, hideForOtherTeams, hideForOwnTeam, never
Collision Rule String Enum (32) always, pushOtherTeams, pushOwnTeam, never
Color Formatting Byte VarInt enum For colors, the same Chat colors (0-15). -1 indicates RESET/no color. See below for more info.
Entity Count VarInt Number of elements in the following array
Entities Array of String (40) Identifiers for the entities in this team. For players, this is their username; for other entities, it is their UUID.
1: remove team no fields no fields
2: update team info Team Display Name String (32)
Team Prefix String (16) Displayed before the names of entities that are part of this team
Team Suffix String (16) Displayed after the names of entities that are part of this team
Friendly Flags Byte Bit mask. 0x01: Allow friendly fire, 0x02: can see invisible entities on same team
Name Tag Visibility String Enum (32) always, hideForOtherTeams, hideForOwnTeam, never
Collision Rule String Enum (32) always, pushOtherTeams, pushOwnTeam, never
Color Formatting Byte VarInt enum For colors, the same Chat colors (0-15). -1 indicates RESET/no color. See below for more info.
3: add players to team Entity Count VarInt Number of elements in the following array
Entities Array of String (40) Identifiers for the entities added. For players, this is their username; for other entities, it is their UUID.
4: remove players from team Entity Count VarInt Number of elements in the following array
Entities Array of String (40) Identifiers for the entities removed. For players, this is their username; for other entities, it is their UUID.

Formatting: The formatting of a team defines how the names of the team members are visualized. The following table lists all the possible formattings.

ID Formatting
0-15 Color formatting, same values as Chat colors.
16 Obfuscated
17 Bold
18 Strikethrough
19 Underlined
20 Italic
21 Reset

Stop Sound

Packet ID State Bound To Field Name Field Type Notes
0x4B Play Client Flags Byte Controls which fields are present.
Source Optional VarInt enum Only if flags is 3 or 1 (bit mask 0x1). See below. If not present, then sounds from all sources are cleared.
Sound Optional Identifier Only if flags is 2 or 3 (bit mask 0x2). A sound effect name, see Named Sound Effect. If not present, then all sounds are cleared.

Categories:

Name Value
master 0
music 1
record 2
weather 3
block 4
hostile 5
neutral 6
player 7
ambient 8
voice 9

Declare Recipes

Packet ID State Bound To Field Name Field Type Notes
0x53 Play Client Num Recipes VarInt Number of elements in the following array
Recipe Recipe ID Array Identifier
Type String The recipe type, see below
Data Optional, varies Additional data for the recipe. For some types, there will be no data.

Recipe types:

Type Description Data
crafting_shapeless Shapeless crafting recipe. All items in the ingredient list must be present, but in any order/slot. As follows:
Name Type Description
Group String Used to group similar recipes together in the recipe book. Tag is present in recipe JSON.
Ingredient count VarInt Number of elements in the following array
Ingredients Array of Ingredient
Result Slot
crafting_shaped Shaped crafting recipe. All items must be present in the same pattern (which may be flipped horizontally or translated) As follows:
Name Type Description
Width VarInt
Height VarInt
Group String Used to group similar recipes together in the recipe book. Tag is present in recipe JSON.
Ingredients Array of Ingredient Length is width * height. Indexed by x + (y * width).
Result Slot
crafting_special_armordye Recipe for dying leather armor None
crafting_special_bookcloning Recipe for copying contents of written books None
crafting_special_mapcloning Recipe for copying maps None
crafting_special_mapextending Recipe for adding paper to maps None
crafting_special_firework_rocket Recipe for making firework rockets None
crafting_special_firework_star Recipe for making firework stars None
crafting_special_firework_star_fade Recipe for making firework stars fade between multiple colors None
crafting_special_repairitem Recipe for repairing items via crafting None
crafting_special_tippedarrow Recipe for crafting tipped arrows None
crafting_special_bannerduplicate Recipe for copying banner patterns None
crafting_special_banneraddpattern Recipe for adding patterns to banners None
crafting_special_shielddecoration Recipe for applying a banner's pattern to a shield None
crafting_special_shulkerboxcoloring Recipe for recoloring a shulker box None

Ingredient is defined as:

Name Type Description
Count VarInt Number of elements in the following array
Items Array of Slot Any item in this array may be used for the recipe. The count of each item should be 1.

Tags

Warning.png This packet MUST be send TWICE, even if it's empty, not doing so can crash the client (e.g. when clicking a fuel slot in a furnace). The packet should also be send two times, this is to prevent the client from crashing.

Packet ID State Bound To Field Name Field Type Notes
0x54 Play Client Block Tags (See below) IDs are block IDs
Item Tags (See below) IDs are item IDs

Tags look like:

Field Name Field Type Notes
Length VarInt Number of elements in the following array
Tags Tag name Array Identifier
Count VarInt Number of elements in the following array
Entries Array of VarInt Numeric ID of the block/item.

Serverbound

Tab-Complete (serverbound)

Sent when the client needs to tab-complete a minecraft:ask_server suggestion type.

Packet ID State Bound To Field Name Field Type Notes
0x01 0x04 Play Server Transaction Id VarInt The id received in the tab completion request packet, must match or the client will ignore this packet. Client generates this and increments it each time it sends another tab completion that doesn't get a response.
Text String (32767 256) All text behind the cursor without the / (e.g. to the left of the cursor in left-to-right languages like English)
Assume Command Boolean If true, the server will parse Text as a command even if it doesn't start with a /. Used in the command block GUI.
Has Position Boolean
Looked At Block Optional Position The position of the block being looked at. Only sent if Has Position is true.

Craft Recipe Request

A replacement for Prepare Crafting Grid. It appears to behave more or less the same, but the client does not specify where to move the items.

This packet is sent when a player clicks a recipe in the crafting book that is craftable (white border).

Packet ID State Bound To Field Name Field Type Notes
0x12 Play Server Window ID Byte
Recipe VarInt Identifier A recipe ID
Make all Boolean Affects the amount of items processed; true if shift is down when clicked

Recipe Book Data

(previously known as Crafting Book Data)

Packet ID State Bound To Field Name Field Type Notes
0x17 Play Server Type VarInt Determines the format of the rest of the packet
Type Field Name
0: Displayed Recipe Recipe ID Int The internal id of the displayed recipe.
1: Recipe Book States Crafting Recipe Book Open Boolean Whether the player has the crafting recipe book currently openened/active.
Crafting Recipe Filter Active Boolean Whether the player has the crafting recipe book filter option currently active.
Smelting Recipe Book Open Boolean Whether the player has the smelting recipe book currently openened/active.
Smelting Recipe Filter Active Boolean Whether the player has the smelting recipe book filter option currently active.

The Recipe Book Status type is send when one of the states changes.

Handshaking

Clientbound

There are no clientbound packets in the Handshaking state, since the protocol immediately switches to a different state after the client sends the first packet.

Serverbound

Handshake

This causes the server to switch into the target state.

Packet ID State Bound To Field Name Field Type Notes
0x00 Handshaking Server Protocol Version VarInt See protocol version numbers (currently 340 371)
Server Address String Hostname or IP, e.g. localhost or 127.0.0.1, that was used to connect. The Notchian server does not use this information.
Server Port Unsigned Short Default is 25565. The Notchian server does not use this information.
Next State VarInt Enum 1 for status, 2 for login

Status

Clientbound

No changes so far.

Serverbound

No changes so far.

Login

Clientbound

No changes so far.

Serverbound

No changes so far.