Difference between revisions of "Pre-release protocol"

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(→‎Declare Commands: Flags are now always a byte)
m (→‎Join Game: Remove burger note; burger has been fixed and the current documentation seems right)
 
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This page documents the changes from the [[Protocol|last stable Minecraft release]] (currently [[Protocol version numbers|1.12.2, protocol 340]]) to the current pre-release (currently [[Protocol version numbers|17w50a, protocol 351]]). Note that this page contains bleeding-edge information that may not be completely or correctly documented.
+
This page documents the changes from the [[Protocol|last stable Minecraft release]] (currently [[Protocol version numbers|1.15.2, protocol 578]]) to the current pre-release (currently [[Protocol version numbers|20w21a, protocol 718]]). 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.
 
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.
Line 9: Line 9:
 
=== Data types ===
 
=== Data types ===
  
==== Other definitions ====
+
The UUID type is now also sometimes encoded by the Notchian server as an array of four 32-bit integers, from most significant to least significant (matching the new format used on entity NBT).  This representation is identical to using 16 bytes, two 64-bit integers, or one 128-bit integers.
 
 
===== Global palette =====
 
A table/dictionary/palette mapping nonnegative integers to block states. {{change|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 assignmentOne 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 [http://pokechu22.github.io/Burger/17w48a.html burger].}}
 
  
 
=== Packets ===
 
=== Packets ===
Line 25: Line 22:
 
  |-
 
  |-
 
!colspan="4"| Play clientbound
 
!colspan="4"| Play clientbound
{{PacketList|0x07|Statistics}}
+
{{PacketList|0x0F|Chat Message (clientbound)}}
{{PacketList|0x0B|Block Change}}
+
{{PacketList|0x22|Chunk Data}}
{{PacketList|{{change|0x0F|0x0E}}|Chat Message (clientbound)|pre=unchanged}}
+
{{PacketList|0x26|Join Game}}
{{PacketList|{{change|0x10|0x0F}}|Multi Block Change}}
+
{{PacketList|0x3B|Respawn}}
{{PacketList|{{change|0x0E|0x10}}|Tab-Complete (clientbound)}}
+
{{PacketList|{{Change|0x4E|0x43}}|Spawn Position|pre=unchanged}}
{{PacketList|0x11|Declare Commands|rel=added}}
+
{{PacketList|{{Change|0x43|0x44}}|Display Scoreboard|pre=unchanged}}
{{PacketList|{{change|0x11|0x12}}|Confirm Transaction (clientbound)|pre=unchanged}}
+
{{PacketList|{{Change|0x44|0x45}}|Entity Metadata|pre=unchanged}}
{{PacketList|{{change|0x12|0x13}}|Close Window (clientbound)|pre=unchanged}}
+
{{PacketList|{{Change|0x45|0x46}}|Attach Entity|pre=unchanged}}
{{PacketList|{{change|0x13|0x14}}|Open Window|pre=unchanged}}
+
{{PacketList|{{Change|0x46|0x47}}|Entity Velocity|pre=unchanged}}
{{PacketList|{{change|0x14|0x15}}|Window Items|pre=unchanged}}
+
{{PacketList|{{Change|0x47|0x48}}|Entity Equipment|pre=unchanged}}
{{PacketList|{{change|0x15|0x16}}|Window Property|pre=unchanged}}
+
{{PacketList|{{Change|0x48|0x49}}|Set Experience|pre=unchanged}}
{{PacketList|{{change|0x16|0x17}}|Set Slot|pre=unchanged}}
+
{{PacketList|{{Change|0x49|0x4A}}|Update Health|pre=unchanged}}
{{PacketList|{{change|0x17|0x18}}|Set Cooldown|pre=unchanged}}
+
{{PacketList|{{Change|0x4A|0x4B}}|Scoreboard Objective|pre=unchanged}}
{{PacketList|{{change|0x18|0x19}}|Plugin Message (clientbound)|pre=unchanged}}
+
{{PacketList|{{Change|0x4B|0x4C}}|Set Passengers|pre=unchanged}}
{{PacketList|{{change|0x19|0x1A}}|Named Sound Effect}}
+
{{PacketList|{{Change|0x4C|0x4D}}|Teams|pre=unchanged}}
{{PacketList|{{change|0x1A|0x1B}}|Disconnect (play)|pre=unchanged}}
+
{{PacketList|{{Change|0x4D|0x4E}}|Update Score|pre=unchanged}}
{{PacketList|{{change|0x1B|0x1C}}|Entity Status|pre=unchanged}}
+
{{PacketList|0x59|Entity Properties}}
{{PacketList|{{change|0x1C|0x1D}}|Explosion|pre=unchanged}}
 
{{PacketList|{{change|0x1D|0x1E}}|Unload Chunk|pre=unchanged}}
 
{{PacketList|{{change|0x1E|0x1F}}|Change Game State|pre=unchanged}}
 
{{PacketList|{{change|0x1F|0x20}}|Keep Alive (clientbound)|pre=unchanged}}
 
{{PacketList|{{change|0x20|0x21}}|Chunk Data}}
 
{{PacketList|{{change|0x21|0x22}}|Effect|pre=unchanged}}
 
{{PacketList|{{change|0x22|0x23}}|Particle}}
 
{{PacketList|{{change|0x23|0x24}}|Join Game|pre=unchanged}}
 
{{PacketList|{{change|0x24|0x25}}|Map|pre=unchanged}}
 
{{PacketList|{{change|0x25|0x26}}|Entity|pre=unchanged}}
 
{{PacketList|{{change|0x26|0x27}}|Entity Relative Move|pre=unchanged}}
 
{{PacketList|{{change|0x27|0x28}}|Entity Look And Relative Move|pre=unchanged}}
 
{{PacketList|{{change|0x28|0x29}}|Entity Look|pre=unchanged}}
 
{{PacketList|{{change|0x29|0x2A}}|Vehicle Move (clientbound)|pre=unchanged}}
 
{{PacketList|{{change|0x2A|0x2B}}|Open Sign Editor|pre=unchanged}}
 
{{PacketList|{{change|0x2B|0x2C}}|Craft Recipe Response}}
 
{{PacketList|{{change|0x2C|0x2D}}|Player Abilities (clientbound)|pre=unchanged}}
 
{{PacketList|{{change|0x2D|0x2E}}|Combat Event|pre=unchanged}}
 
{{PacketList|{{change|0x2E|0x2F}}|Player List Item|pre=unchanged}}
 
{{PacketList|{{change|0x2F|0x30}}|Player Position And Look (clientbound)|pre=unchanged}}
 
{{PacketList|{{change|0x30|0x31}}|Use Bed|pre=unchanged}}
 
{{PacketList|{{change|0x31|0x32}}|Unlock Recipes}}
 
{{PacketList|{{change|0x32|0x33}}|Destroy Entities|pre=unchanged}}
 
{{PacketList|{{change|0x33|0x34}}|Remove Entity Effect|pre=unchanged}}
 
{{PacketList|{{change|0x34|0x35}}|Resource Pack Send|pre=unchanged}}
 
{{PacketList|{{change|0x35|0x36}}|Respawn|pre=unchanged}}
 
{{PacketList|{{change|0x36|0x37}}|Entity Head Look|pre=unchanged}}
 
{{PacketList|{{change|0x37|0x38}}|Select Advancement Tab|pre=unchanged}}
 
{{PacketList|{{change|0x38|0x39}}|World Border|pre=unchanged}}
 
{{PacketList|{{change|0x39|0x3A}}|Camera|pre=unchanged}}
 
{{PacketList|{{change|0x3A|0x3B}}|Held Item Change (clientbound)|pre=unchanged}}
 
{{PacketList|{{change|0x3B|0x3C}}|Display Scoreboard|pre=unchanged}}
 
{{PacketList|{{change|0x3C|0x3D}}|Entity Metadata|pre=unchanged}}
 
{{PacketList|{{change|0x3D|0x3E}}|Attach Entity|pre=unchanged}}
 
{{PacketList|{{change|0x3E|0x3F}}|Entity Velocity|pre=unchanged}}
 
{{PacketList|{{change|0x3F|0x40}}|Entity Equipment|pre=unchanged}}
 
{{PacketList|{{change|0x40|0x41}}|Set Experience|pre=unchanged}}
 
{{PacketList|{{change|0x41|0x42}}|Update Health|pre=unchanged}}
 
{{PacketList|{{change|0x42|0x43}}|Scoreboard Objective}}
 
{{PacketList|{{change|0x43|0x44}}|Set Passengers|pre=unchanged}}
 
{{PacketList|{{change|0x44|0x45}}|Teams|pre=unchanged}}
 
{{PacketList|{{change|0x45|0x46}}|Update Score|pre=unchanged}}
 
{{PacketList|{{change|0x46|0x47}}|Spawn Position|pre=unchanged}}
 
{{PacketList|{{change|0x47|0x48}}|Time Update|pre=unchanged}}
 
{{PacketList|{{change|0x48|0x49}}|Title|pre=unchanged}}
 
{{PacketList|0x4A|Stop Sound|rel=added}}
 
{{PacketList|{{change|0x49|0x4B}}|Sound Effect|pre=unchanged}}
 
{{PacketList|{{change|0x4A|0x4C}}|Player List Header And Footer|pre=unchanged}}
 
{{PacketList|{{change|0x4B|0x4D}}|Collect Item|pre=unchanged}}
 
{{PacketList|{{change|0x4C|0x4E}}|Entity Teleport|pre=unchanged}}
 
{{PacketList|{{change|0x4D|0x4F}}|Advancements|pre=unchanged}}
 
{{PacketList|{{change|0x4E|0x50}}|Entity Properties|pre=unchanged}}
 
{{PacketList|{{change|0x4F|0x51}}|Entity Effect|pre=unchanged}}
 
{{PacketList|0x52|Declare Recipes|rel=added}}
 
{{PacketList|0x53|Tags|rel=added}}
 
 
  |-
 
  |-
 
!colspan="4"| Play serverbound
 
!colspan="4"| Play serverbound
{{PacketList|{{change|0x02|0x01}}|Chat Message (serverbound)|pre=unchanged}}
+
{{PacketList|0x0F|Generate Structure|rel=added}}
{{PacketList|{{change|0x03|0x02}}|Client Status|pre=unchanged}}
+
{{PacketList|{{change|0x0F|0x10}}|Keep Alive (serverbound)|pre=unchanged}}
{{PacketList|{{change|0x04|0x03}}|Client Settings|pre=unchanged}}
+
{{PacketList|{{change|0x10|0x11}}|Lock Difficulty|pre=unchanged}}
{{PacketList|{{change|0x01|0x04}}|Tab-Complete (serverbound)}}
+
{{PacketList|{{change|0x11|0x12}}|Player Position|pre=unchanged}}
{{PacketList|0x12|Craft Recipe Request}}
+
{{PacketList|{{change|0x12|0x13}}|Player Position And Rotation (serverbound)|pre=unchanged}}
 +
{{PacketList|{{change|0x13|0x14}}|Player Rotation|pre=unchanged}}
 +
{{PacketList|{{change|0x14|0x15}}|Player Movement|pre=unchanged}}
 +
{{PacketList|{{change|0x15|0x16}}|Vehicle Move (serverbound)|pre=unchanged}}
 +
{{PacketList|{{change|0x16|0x17}}|Steer Boat|pre=unchanged}}
 +
{{PacketList|{{change|0x17|0x18}}|Pick Item|pre=unchanged}}
 +
{{PacketList|{{change|0x18|0x19}}|Craft Recipe Request|pre=unchanged}}
 +
{{PacketList|{{change|0x19|0x1A}}|Player Abilities (serverbound)|pre=unchanged}}
 +
{{PacketList|{{change|0x1A|0x1B}}|Player Digging|pre=unchanged}}
 +
{{PacketList|{{change|0x1B|0x1C}}|Entity Action|pre=unchanged}}
 +
{{PacketList|{{change|0x1C|0x1D}}|Steer Vehicle|pre=unchanged}}
 +
{{PacketList|{{change|0x1D|0x1E}}|Recipe Book Data|pre=unchanged}}
 +
{{PacketList|{{change|0x1E|0x1F}}|Name Item|pre=unchanged}}
 +
{{PacketList|{{change|0x1F|0x20}}|Resource Pack Status|pre=unchanged}}
 +
{{PacketList|{{change|0x20|0x21}}|Advancement Tab|pre=unchanged}}
 +
{{PacketList|{{change|0x21|0x22}}|Select Trade|pre=unchanged}}
 +
{{PacketList|{{change|0x22|0x23}}|Set Beacon Effect|pre=unchanged}}
 +
{{PacketList|{{change|0x23|0x24}}|Held Item Change (serverbound)|pre=unchanged}}
 +
{{PacketList|{{change|0x24|0x25}}|Update Command Block|pre=unchanged}}
 +
{{PacketList|{{change|0x25|0x26}}|Update Command Block Minecart|pre=unchanged}}
 +
{{PacketList|{{change|0x26|0x27}}|Creative Inventory Action|pre=unchanged}}
 +
{{PacketList|{{change|0x27|0x28}}|Update Jigsaw Block}}
 +
{{PacketList|{{change|0x28|0x29}}|Update Structure Block|pre=unchanged}}
 +
{{PacketList|{{change|0x29|0x2A}}|Update Sign|pre=unchanged}}
 +
{{PacketList|{{change|0x2A|0x2B}}|Animation (serverbound)|pre=unchanged}}
 +
{{PacketList|{{change|0x2B|0x2C}}|Spectate|pre=unchanged}}
 +
{{PacketList|{{change|0x2C|0x2D}}|Player Block Placement|pre=unchanged}}
 +
{{PacketList|{{change|0x2D|0x2E}}|Use Item|pre=unchanged}}
 +
|-
 +
!colspan="4"| Login clientbound
 +
{{PacketList|0x02|Login Success}}
 
  |}
 
  |}
  
 
== New/modified data types ==
 
== New/modified data types ==
  
=== [[Slot]] ===
+
No changes so far.
  
{| class="wikitable"
+
== Entity Metadata ==
! Name
 
! Type
 
! Meaning
 
|-
 
| {{Change|Block ID|Item ID}}
 
| Short
 
| The {{Minecraft Wiki|Data values#Block IDs|item{{change|/block}} ID}}. A value of <code>-1</code> signifies that the slot is empty, and no further data follows. {{Change||Item IDs are now uniquely defined and are completely independent of block IDs.}}
 
|-
 
| Item Count
 
| Optional Byte
 
| Not present if Block ID is <code>-1</code>.
 
|- style="background-color: #f4cccc; text-decoration: line-through;"
 
| Item Damage
 
| Optional Short
 
| Not present if Block ID is <code>-1</code>.
 
|-
 
| NBT
 
| Optional NBT
 
| Not present if Block ID is <code>-1</code>. 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:
 
|}
 
  
== Block Actions ==
+
{{#vardefine:meta_prerelease|1}}
  
No changes so far.
+
=== FishingHook ===
  
== Plugin Channels ==
+
{{Metadata inherit|FishingHook|inherits=Entity|start_at=7}}
 
 
=== <code>MC|StopSound</code> ===
 
 
 
{{Change|''Server to client''}}
 
 
 
{{Change|Used to implement {{Minecraft Wiki|Commands#StopSound|the <code>/stopsound</code> command}}.  Stops a sound that is currently playing on the client.}}
 
 
 
{| class="wikitable" style="background-color: #f4cccc; text-decoration: line-through;"
 
! Field name
 
! Field type
 
! Notes
 
|-
 
| Sound category
 
| String
 
| Should be one of the sound categories used in [[Protocol#Named Sound Effect|Named Sound Effect]], but if it's invalid or empty then it is (intentionally) treated as ''all'' sound categories.
 
|-
 
| Sound name
 
| String
 
| A [http://pokechu22.github.io/Burger/1.11.html#sounds sound effect name].  If left empty, ''all'' sounds are stopped.
 
|}
 
 
 
{{Change|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.}}
 
 
 
{{Change||This plugin channel has been replaced by the [[#Stop sound|stop sound]] packet.}}
 
 
 
== Play ==
 
 
 
=== Clientbound ===
 
 
 
==== Block Change ====
 
 
 
Fired whenever a block is changed within the render distance.
 
 
 
{{Warning2|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.}}
 
  
 
{| class="wikitable"
 
{| class="wikitable"
  ! Packet ID
+
  ! Index
  ! State
+
  ! Type
! Bound To
+
  !style="width: 250px;" colspan="2"| Meaning
! Field Name
+
  ! Default
! Field Type
 
  ! Notes
 
|-
 
|rowspan="2"| 0x0B
 
|rowspan="2"| Play
 
|rowspan="2"| Client
 
  | Location
 
| Position
 
| Block Coordinates
 
 
  |-
 
  |-
  | Block ID
+
  | {{Metadata id|}}
 
  | VarInt
 
  | VarInt
  | The new block state ID for the block as given in the [[#global palette|global palette]]. {{change|(When reading data: <code>type {{=}} id >> 4</code>, <code>meta {{=}} id & 15</code>, when writing data: <code>id {{=}} type << 4 {{!}} (meta & 15)</code>)|See that section for more information.}}
+
  |colspan="2"| Hooked entity id + 1, or 0 if there is no hooked entity
 +
| 0
 +
  |- {{Added}}
 +
| {{Metadata id|added}}
 +
| Boolean
 +
|colspan="2"| Is catchable
 +
| False
 
  |}
 
  |}
  
 +
=== Abstract Arrow ===
  
==== Statistics ====
+
{{Metadata inherit|Abstract Arrow|inherits=Entity|start_at=7}}
  
Sent as a response to [[#Client_Status|Client Status]] (id 1).
+
Abstract base class for [[#Tipped Arrow|Tipped Arrow]] (which is used for regular arrows as well as tipped ones) and [[#Spectral Arrow|Spectral Arrow]].
  
 
{| class="wikitable"
 
{| class="wikitable"
  ! Packet ID
+
  ! Index
  ! State
+
  ! Type
  ! Bound To
+
  !style="width: 250px;" colspan="2"| Meaning
  !colspan="2"| Field Name
+
  ! Default
  !colspan="2"| Field Type
+
|-
  ! Notes
+
| rowspan="3" | {{Metadata id|}}
 +
  | rowspan="3" | Byte
 +
! Bit mask
 +
  ! Meaning
 +
| rowspan="3" | 0
 
  |-
 
  |-
  |rowspan="6"| 0x07
+
  | 0x01
|rowspan="6"| Play
+
  | Is critical
|rowspan="6"| Client
 
|colspan="2"| Count
 
|colspan="2"| VarInt
 
  | Number of elements in the following array
 
 
  |-
 
  |-
  |rowspan="4"| Statistic
+
  | 0x02
|style="background-color: #f4cccc; text-decoration: line-through;"| Name
+
  | Is noclip (used by loyalty tridents when returning)
|rowspan="4"| Array
+
  |- {{removed}}
  |style="background-color: #f4cccc; text-decoration: line-through;"| String (32767)
+
  | {{Metadata id|removed}}
  |style="background-color: #f4cccc; text-decoration: line-through;"| [https://gist.github.com/Alvin-LB/8d0d13db00b3c00fd0e822a562025eff https://gist.github.com/Alvin-LB/8d0d13db00b3c00fd0e822a562025eff]
+
  | OptUUID
  |- style="background-color: #d9ead3;"
+
  |colspan="2"| Unused
| Unknown 1
+
  | Empty
| VarInt
 
  |
 
  |- style="background-color: #d9ead3;"
 
| Unknown 2
 
| VarInt
 
  |
 
 
  |-
 
  |-
  | Value
+
  | {{Metadata id|}}
  | VarInt
+
  | Byte
  | The amount to set it to
+
|colspan="2"| Peircing level
 +
  | 0
 
  |}
 
  |}
  
==== Multi Block Change ====
+
=== Tipped Arrow ===
  
Fired whenever 2 or more blocks are changed within the same chunk on the same tick.
+
{{Metadata inherit|Tipped Arrow|inherits=Abstract Arrow}}
  
{{Warning|Changing blocks in chunks not loaded by the client is unsafe (see note on [[#Block Change|Block Change]]).}}
+
Used for both tipped and regular arrows.  If not tipped, then color is set to -1 and no tipped arrow particles are used.
  
 
{| class="wikitable"
 
{| class="wikitable"
  ! Packet ID
+
  ! Index
  ! State
+
  ! Type
! Bound To
+
  !style="width: 250px;" colspan="2"| Meaning
  !colspan="2"| Field Name
+
  ! Default
!colspan="2"| Field Type
 
  ! Notes
 
|-
 
|rowspan="6"| {{Change|0x10|0x0F}}
 
|rowspan="6"| Play
 
|rowspan="6"| Client
 
|colspan="2"| Chunk X
 
|colspan="2"| Int
 
| Chunk X coordinate
 
 
  |-
 
  |-
  |colspan="2"| Chunk Z
+
  | {{Metadata id|}}
|colspan="2"| Int
 
| Chunk Z coordinate
 
|-
 
|colspan="2"| Record Count
 
|colspan="2"| VarInt
 
| Number of elements in the following array, i.e. the number of blocks affected
 
|-
 
|rowspan="3"| Record
 
| Horizontal Position
 
|rowspan="3"| Array
 
| Unsigned Byte
 
| The 4 most significant bits (<code>0xF0</code>) encode the X coordinate, relative to the chunk. The 4 least significant bits (<code>0x0F</code>) encode the Z coordinate, relative to the chunk.
 
|-
 
| Y Coordinate
 
| Unsigned Byte
 
| Y coordinate of the block
 
|-
 
| Block ID
 
 
  | VarInt
 
  | VarInt
  | The new block state ID for the block as given in the [[#global palette|global palette]].  {{change|(When reading data: <code>type {{=}} id >> 4</code>, <code>meta {{=}} id & 15</code>, when writing data: <code>id {{=}} type << 4 {{!}} (meta & 15)</code>)|See that section for more information.}}
+
  |colspan="2"| Color (-1 for no particles)
 +
| -1
 
  |}
 
  |}
  
To decode the position into a world position:
+
=== Spectral Arrow ===
 
 
<syntaxhighlight lang="java">
 
worldX = (horizPos >> 4 & 15) + (chunkX * 16);
 
worldY = vertPos;
 
worldZ = (horizPos & 15) + (chunkZ * 16);
 
</syntaxhighlight>
 
  
 +
{{Metadata inherit|Spectral Arrow|inherits=Abstract Arrow}}
  
==== Tab-Complete (clientbound) ====
+
No additional metadata.
  
{{Need Info|This is most definitely no longer an accurate description of this packet}}
+
=== Trident ===
  
The server responds with a list of auto-completions of the last word sent to it. In the case of regular chat, this is a player username. Command names and parameters are also supported. The client sorts these alphabetically before listing them.
+
{{Metadata inherit|Trident|inherits=Abstract Arrow}}
  
 
{| class="wikitable"
 
{| class="wikitable"
  ! Packet ID
+
  ! Index
  ! State
+
  ! Type
! Bound To
+
  !style="width: 250px;" colspan="2"| Meaning
! Field Name
+
  ! Default
  ! Field Type
 
  ! Notes
 
 
  |-
 
  |-
  |rowspan="5"| {{Change|0x0E|0x10}}
+
  | {{Metadata id|}}
|rowspan="5"| Play
 
|rowspan="5"| Client
 
|style="background-color: #d9ead3;"| Transaction Id
 
|style="background-color: #d9ead3;"| VarInt
 
|style="background-color: #d9ead3;"| This id should also be used in the tab completion response packet, or it will be ignored.
 
|- style="background-color: #d9ead3;"
 
| Start
 
 
  | VarInt
 
  | VarInt
  |
+
  |colspan="2"| Loyalty level (enchantment)
|- style="background-color: #d9ead3;"
+
  | 0
| Length
 
| VarInt
 
  |
 
 
  |-
 
  |-
  | Count
+
  | {{Metadata id|}}
| VarInt
+
  | Boolean
  | Number of elements in the following array
+
  |colspan="2"| Has enchantment glint
  |-
+
  | False
| Matches
 
| Array of String (32767)
 
  | One eligible command, note that each command is sent separately instead of in a single string, hence the need for Count
 
 
  |}
 
  |}
  
==== Declare Commands ====
+
=== Strider ===
  
{{Need Info|This information is probably incomplete/inaccurate}}
+
{{Metadata inherit|Strider|inherits=Animal|start_at=16}}
  
Lists all of the commands on the server, and how they are parsed.
+
{| class="wikitable" {{added}}
 
+
  ! Index
{| class="wikitable"
+
  ! Type
  ! Packet ID
+
  !style="width: 250px;" colspan="2"| Meaning
  ! State
+
  ! Default
  ! Bound To
 
! Field Name
 
! Field Type
 
  ! Notes
 
 
  |-
 
  |-
  |rowspan="3"| 0x11
+
  | {{Metadata id|}}
|rowspan="3"| Play
 
|rowspan="3"| Client
 
| Count
 
 
  | VarInt
 
  | VarInt
  | Length of the following array
+
  |colspan="2"| Total time to "boost" with warped fungus on a stick for
 +
| 0
 
  |-
 
  |-
  | Nodes
+
  | {{Metadata id|}}
  | Array of Node
+
  | Boolean
  | A array of <code>CommandNode</code>s
+
|colspan="2"| Should display name tag (true unless riding a vehicle or on or in a block tagged with strider_warm_blocks (default: lava))
 +
  | false
 
  |-
 
  |-
  | Root index
+
  | {{Metadata id|}}
  | VarInt
+
  | Boolean
  | Index of the <code>RootCommandNode</code> in the previous array
+
|colspan="2"| Has saddle
 +
  | false
 
  |}
 
  |}
  
Node:
+
=== Hoglin ===
  
{| class="wikitable"
+
{{Metadata inherit|Hoglin|inherits=Animal|start_at=16}}
  ! Field Name
+
 
  ! Field Type
+
{| class="wikitable" {{added}}
  ! Notes
+
  ! Index
 +
  ! Type
 +
  !style="width: 250px;" colspan="2"| Meaning
 +
! Default
 
  |-
 
  |-
  | Flags
+
  | {{Metadata id|}}
  | Byte
+
  | Boolean
  |
+
  |colspan="2"| Is immune to zombification
  {| class="wikitable"
+
  | false
  ! Bit mask
 
  !colspan="2"| Meaning
 
  |-
 
  |rowspan="4"| 0x03
 
  |colspan="2"| Type of the <code>CommandNode</code>
 
  |-
 
  |0
 
  |<code>RootCommandNode</code>
 
  |-
 
  |1
 
  |<code>LiteralCommandNode</code>
 
  |-
 
  |2
 
  |<code>ArgumentCommandNode</code>
 
  |-
 
  |0x04
 
  |colspan="2"| Has command
 
  |-
 
  |0x08
 
  |colspan="2"| Has redirect node
 
  |-
 
  |0x10
 
  |colspan="2"| Has custom suggestions, currently only present if the type is a <code>ArgumentCommandNode</code>
 
  |}
 
|-
 
| Children Count
 
| VarInt
 
| Length of the following array
 
|-
 
| Children
 
| Array of VarInt
 
| The indexes of the children <code>CommandNode</code>s within the <code>Nodes</code> array
 
|-
 
| Redirect node
 
| Optional VarInt
 
| Only if flags & 0x08. Points to the redirect <code>CommandNode</code> within the <code>Nodes</code> array
 
|-
 
| Extra node data
 
| Extra node data
 
  | Type depends on the <code>CommandNode</code> type, see below.
 
 
  |}
 
  |}
  
Extra node data:
+
=== Zoglin ===
{| class="wikitable"
+
 
 +
{{Metadata inherit|Hoglin|inherits=Monster|start_at=15}}
 +
 
 +
{| class="wikitable" {{added}}
 +
! Index
 
  ! Type
 
  ! Type
  ! Field Name
+
  !style="width: 250px;" colspan="2"| Meaning
  ! Field Type
+
  ! Default
! Notes
 
 
  |-
 
  |-
  | <code>RootCommandNode</code>
+
  | {{Metadata id|}}
| Empty
+
  | Boolean
| Empty
+
  |colspan="2"| Is baby
|
+
  | false
|-
 
| <code>LiteralCommandNode</code>
 
| Literal
 
  | String (32767)
 
  | The text
 
|-
 
|rowspan="4"| <code>ArgumentCommandNode</code>
 
| 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:
+
=== Piglin ===
  
{| class="wikitable"
+
{{Metadata inherit|Piglin|inherits=Monster|start_at=15}}
  ! Identifier
+
 
  ! Description
+
{| class="wikitable" {{added}}
  ! Properties
+
  ! Index
 +
  ! Type
 +
!style="width: 250px;" colspan="2"| Meaning
 +
  ! Default
 
  |-
 
  |-
  | <code>brigadier:bool</code>
+
  | {{Metadata id|}}
  | Boolean value (<code>true</code> or <code>false</code>, case-sensitive)
+
  | Boolean
  | None
+
  |colspan="2"| Is baby
 +
| false
 
  |-
 
  |-
  | <code>brigadier:double</code>
+
  | {{Metadata id|}}
  | Double
+
  | Boolean
  | Specifies min and max values:
+
  |colspan="2"| Is immune to zombification
  {| class="wikitable"
+
  | false
  ! Name
 
  ! Type
 
  ! Description
 
  |-
 
  | Flags
 
  | Byte
 
  |
 
  |-
 
  | Min
 
  | Optional double
 
  | Only if flags & 0x01.  If not specified, defaults to <code>-Double.MAX_VALUE</code> (≈ -1.7976931348623157E307)
 
  |-
 
  | Max
 
  | Optional double
 
  | Only if flags & 0x02. If not specified, defaults to <code>Double.MAX_VALUE</code> (≈ 1.7976931348623157E307)
 
  |}
 
 
  |-
 
  |-
  | <code>brigadier:float</code>
+
  | {{Metadata id|}}
| Float
+
  | Boolean
| Specifies min and max values:
+
  |colspan="2"| Is charging crossbow
  {| class="wikitable"
+
  | false
  ! Name
 
  ! Type
 
  ! Description
 
  |-
 
  | Flags
 
  | Byte
 
  |
 
  |-
 
  | Min
 
  | Optional float
 
  | Only if flags & 0x01.  If not specified, defaults to <code>-Float.MAX_VALUE</code> (≈ -3.4028235E38)
 
  |-
 
  | Max
 
  | Optional float
 
  | Only if flags & 0x02.  If not specified, defaults to <code>Float.MAX_VALUE</code> (≈ 3.4028235E38)
 
  |}
 
|-
 
| <code>brigadier:integer</code>
 
| Integer
 
| Specifies min and max values:
 
  {| class="wikitable"
 
  ! Name
 
  ! Type
 
  ! Description
 
  |-
 
  | Flags
 
  | Byte
 
  |
 
  |-
 
  | Min
 
  | Optional integer
 
  | Only if flags & 0x01.  If not specified, defaults to <code>Integer.MIN_VALUE</code> (-2147483648)
 
  |-
 
  | Max
 
  | Optional integer
 
  | Only if flags & 0x02.  If not specified, defaults to <code>Integer.MAX_VALUE</code> (2147483647)
 
  |}
 
|-
 
| <code>brigadier:string</code>
 
| A string
 
| A VarInt enum:
 
  {| class="wikitable"
 
  ! Value
 
  ! Name
 
  ! Description
 
  |-
 
  | 0
 
  | <code>SINGLE_WORD</code>
 
  | Reads a single word
 
  |-
 
  | 1
 
  | <code>QUOTABLE_PHRASE</code>
 
  | If it starts with a <code>"</code>, keeps reading until another <code>"</code> (allowing escaping with <code>\</code>).  Otherwise behaves the same as <code>SINGLE_WORD</code>
 
  |-
 
  | 2
 
  | <code>GREEDY_PHRASE</code>
 
  | Reads the rest of the content after the cursor.  Quotes will not be removed.
 
  |}
 
  |-
 
  | <code>minecraft:entity</code>
 
| A selector, player name, or UUID.
 
| Has a single flags byte:
 
  {| class="wikitable"
 
  ! Bit mask
 
  ! Meaning
 
  |-
 
  | 0x01
 
  | Only allows 1 entity/player
 
  |-
 
  | 0x02
 
  | Only allows players
 
  |}
 
|-
 
| <code>minecraft:game_profile</code>
 
| A player, online or not.  Can also use a selector, which may match one or more players (but not entities).
 
| None
 
|-
 
| <code>minecraft:block_pos</code>
 
| A location, represented as 3 numbers (which must be integers).  May use relative locations with <code>~</code>.
 
| None
 
|-
 
| <code>minecraft:vec3</code>
 
| 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 <code>~</code>.
 
| None
 
|-
 
| <code>minecraft:vec2</code>
 
| 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 <code>~</code>.
 
| None
 
|-
 
| <code>minecraft:block</code>
 
| A block state, optionally including NBT and state information.
 
| None
 
|-
 
| <code>minecraft:item</code>
 
| An item, optionally including NBT.
 
| None
 
|-
 
| <code>minecraft:color</code>
 
| A chat color.  One of the names from [[Chat#Colors]], or <code>reset</code>.  Case-insensitive.
 
| None
 
|-
 
| <code>minecraft:component</code>
 
| A JSON [[Chat]] component.
 
| None
 
|-
 
| <code>minecraft:message</code>
 
| A regular message, potentially including selectors.
 
| None
 
|-
 
| <code>minecraft:nbt</code>
 
| An NBT value, parsed using JSON-NBT rules.
 
| None
 
|-
 
| <code>minecraft:nbt_path</code>
 
| A path within an NBT value, allowing for array and member accesses.
 
| None
 
|-
 
| <code>minecraft:objective</code>
 
| A scoreboard objective.
 
| None
 
|-
 
| <code>minecraft:objective_criteria</code>
 
| A single score criterion.
 
| None
 
|-
 
| <code>minecraft:operation</code>
 
| A scoreboard operator
 
| None
 
|-
 
| <code>minecraft:particle</code>
 
| A particle effect (an identifier with extra information following it for specific particles, mirroring the [[#Particle|Particle]] packet)
 
| None
 
|-
 
| <code>minecraft:rotation</code>
 
| 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 <code>~</code>.
 
| None
 
|-
 
| <code>minecraft:scoreboard_slot</code>
 
| A scoreboard display position slot.  <code>list</code>, <code>sidebar</code>, <code>belowName</code>, and <code>sidebar.team.${color}</code> for all chat colors (<code>reset</code> is not included)
 
| None
 
|-
 
| <code>minecraft:score_holder</code>
 
| Something that can join a team.  Allows selectors and <code>*</code>.
 
| Has a single flags byte:
 
  {| class="wikitable"
 
  ! Bit mask
 
  ! Meaning
 
  |-
 
  | 0x01
 
  | Unknown.
 
  |-
 
  | 0x02
 
  | Unknown.
 
  |}
 
|-
 
| <code>minecraft:swizzle</code>
 
| A collection of up to 3 axes.
 
| None
 
|-
 
| <code>minecraft:team</code>
 
| The name of a team.  Parsed as an unquoted string.
 
| None
 
|-
 
| <code>minecraft:item_slot</code>
 
| A name for an inventory slot.
 
| None
 
|-
 
| <code>minecraft:resource_location</code>
 
| An Identifier.
 
| None
 
|-
 
| <code>minecraft:mob_effect</code>
 
| A potion effect.
 
  | None
 
 
  |}
 
  |}
  
Suggestion types:
+
=== {{Change|Zombie Pigman|Zombified Piglin}} ===
 +
 
 +
{{Metadata inherit|{{Change|Zombie Pigman|Zombified Piglin}}|inherits=Zombie|start_at=18}}
 +
 
 +
No additional metadata.
 +
 
 +
== Block Actions ==
 +
 
 +
No changes so far.
 +
 
 +
== Inventories ==
 +
 
 +
No changes so far.
 +
 
 +
== Plugin Channels ==
 +
 
 +
No changes so far.
 +
 
 +
== Play ==
 +
 
 +
=== Clientbound ===
  
{| class="wikitable"
+
==== Chat Message (clientbound) ====
  ! Identifier
 
  ! Description
 
  |-
 
  | <code>minecraft:ask_server</code>
 
  | Sends the <code>Tab-Complete</code> packet to the server to request tab completions.
 
  |-
 
  | <code>minecraft:all_recipes</code>
 
  | Suggests all the available recipes.
 
  |-
 
  | <code>minecraft:available_sounds</code>
 
  | Suggests all the available sounds.
 
  |-
 
  | <code>minecraft:summonable_entities</code>
 
  | Suggests all the summonable entities.
 
  |}
 
  
==== Named Sound Effect ====
+
Identifying the difference between Chat/System Message is important as it helps respect the user's chat visibility options.  See [[Chat#Processing chat|processing chat]] for more info about these positions.
{{See also|#Sound Effect}}
 
  
Used to play a sound effect on the client. Custom sounds may be added by resource packs.
+
{{warning2|Game info accepts json formatting but does not display it, although the deprecated §-based formatting works. This is not an issue when using the [[#Title|Title]] packet, so prefer that packet for displaying information in that slot.  See [https://bugs.mojang.com/browse/MC-119145 MC-119145] for more information.}}
  
 
{| class="wikitable"
 
{| class="wikitable"
Line 684: Line 307:
 
  ! Notes
 
  ! Notes
 
  |-
 
  |-
  |rowspan="7"| {{Change|0x19|0x1A}}
+
  |rowspan="3"| 0x0F
  |rowspan="7"| Play
+
  |rowspan="3"| Play
  |rowspan="7"| Client
+
  |rowspan="3"| Client
  | Sound Name
+
  | JSON Data
  | {{Change|String (256)|Identifier}}
+
  | [[Chat]]
  | All sound effect names as of 1.12.2 can be seen [http://pokechu22.github.io/Burger/1.12.2.html#sounds here].
+
  | Limited to 32767 bytes
 
  |-
 
  |-
  | Sound Category
+
  | Position
  | VarInt Enum
+
  | Byte
  | The category that this sound will be played from ([https://gist.github.com/konwboj/7c0c380d3923443e9d55 current categories])
+
  | 0: chat (chat box), 1: system message (chat box), 2: game info (above hotbar).
|-
+
  |- {{added}}
| Effect Position X
+
  | Sender
| Int
+
  | UUID
| Effect X multiplied by 8 ([[Data types#Fixed-point numbers|fixed-point number]] with only 3 bits dedicated to the fractional part)
+
  | Used by the Notchian client for the disableChat launch option. Setting both longs to 0 will always display the message regardless of the setting.
  |-
 
  | Effect Position Y
 
  | Int
 
  | Effect Y multiplied by 8 ([[Data types#Fixed-point numbers|fixed-point number]] with only 3 bits dedicated to the fractional part)
 
|-
 
| Effect Position Z
 
| Int
 
| Effect Z multiplied by 8 ([[Data types#Fixed-point numbers|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
 
 
  |}
 
  |}
  
Line 719: Line 326:
 
{{Main|Chunk Format}}
 
{{Main|Chunk Format}}
 
{{See also|#Unload Chunk}}
 
{{See also|#Unload Chunk}}
 +
 +
{{Need Info|How do biomes work now?  The biome change happened at the same time as the seed change, but it's not clear how/if biomes could be computed given that it's not the actual seed...  ([https://www.reddit.com/r/Mojira/comments/e5at6i/a_discussion_for_the_changes_to_how_biomes_are/ /r/mojira discussion] which notes that it seems to be some kind of interpolation, and 3D biomes are only used in the nether)}}
  
 
The server only sends skylight information for chunk pillars in the {{Minecraft Wiki|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|Update Block Entity]] later).
 
The server only sends skylight information for chunk pillars in the {{Minecraft Wiki|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|Update Block Entity]] later).
 
{{Change||Indexes into the global palette are still used, but since the global palette has changed, behavior is different.}}
 
  
 
{| class="wikitable"
 
{| class="wikitable"
Line 732: Line 339:
 
  ! Notes
 
  ! Notes
 
  |-
 
  |-
  |rowspan="9"| {{Change|0x20|0x21}}
+
  |rowspan="10"| 0x22
  |rowspan="9"| Play
+
  |rowspan="10"| Play
  |rowspan="9"| Client
+
  |rowspan="10"| Client
 
  | Chunk X
 
  | Chunk X
 
  | Int
 
  | Int
Line 743: Line 350:
 
  | Chunk coordinate (block coordinate divided by 16, rounded down)
 
  | Chunk coordinate (block coordinate divided by 16, rounded down)
 
  |-
 
  |-
  | Ground-Up Continuous
+
  | Full chunk
 
  | Boolean
 
  | Boolean
  | See [[Chunk Format#Ground-up continuous|Chunk Format]]
+
  | See [[Chunk Format#Full chunk|Chunk Format]]
 
  |-
 
  |-
 
  | Primary Bit Mask
 
  | Primary Bit Mask
 
  | VarInt
 
  | 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).
 
  | 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).
 +
|-
 +
| Heightmaps
 +
| [[NBT]]
 +
| Compound containing one long array named <code>MOTION_BLOCKING</code>, which is a heightmap for the highest solid block at each position in the chunk (as a compacted long array with 256 entries at 9 bits per entry totaling 36 longs). The Notchian server also adds a <code>WORLD_SURFACE</code> long array, the purpose of which is unknown, but it's not required for the chunk to be accepted.
 +
|-
 +
| Biomes
 +
| Optional array of Integer
 +
| 1024 biome IDs, ordered by x then z then y, in 4&times;4&times;4 blocks.  Not present if full chunk is false.
 
  |-  
 
  |-  
 
  | Size
 
  | Size
Line 761: Line 376:
 
  | Number of block entities
 
  | Number of block entities
 
  | VarInt
 
  | VarInt
  | Length of the following array
+
  | Number of elements in the following array
 
  |-
 
  |-
 
  | Block entities
 
  | Block entities
Line 768: Line 383:
 
  |}
 
  |}
  
 +
Note that the Notchian client requires an [[#Update View Position|Update View Position]] packet when it crosses a chunk border, otherwise it'll only display render distance + 2 chunks around the chunk it spawned in.
 +
 +
{{Change||The compacted array format has been adjusted so that individual entries no longer span across multiple longs, affecting the main data array and heightmaps.}}
  
==== Particle ====
+
==== Join Game ====
  
Displays the named particle
+
See [[Protocol Encryption]] for information on logging in.
  
 
{| class="wikitable"
 
{| class="wikitable"
Line 781: Line 399:
 
  ! Notes
 
  ! Notes
 
  |-
 
  |-
  |rowspan="11"| {{Change|0x22|0x23}}
+
  |rowspan="12"| 0x26
  |rowspan="11"| Play
+
  |rowspan="12"| Play
  |rowspan="11"| Client
+
  |rowspan="12"| Client
  | Particle ID
+
  | Entity ID
 
  | Int
 
  | Int
  | See below
+
  | The player's Entity ID (EID)
 
  |-
 
  |-
  | Long Distance
+
  | Gamemode
  | Boolean
+
  | Unsigned Byte
  | If true, particle distance increases from 256 to 65536
+
  | 0: Survival, 1: Creative, 2: Adventure, 3: Spectator. Bit 3 (0x8) is the hardcore flag.
 +
|- {{Added}}
 +
| Dimension Codec
 +
| [[NBT|NBT Tag Compound]]
 +
| This CompoundTag contains a ListTag named "dimension". The ListTag should contain CompoundTags with named StringTags "key" and "element". The full extent of these is still unknown, but the tag represents a dimension registry. See below for the vanilla default.
 
  |-
 
  |-
  | X
+
  | Dimension
  | Float
+
  | {{change|Int Enum|Identifier}}
  | X position of the particle
+
  | {{change|-1: The Nether, 0: The Overworld, 1: The End|Valid dimensions are defined per dimension registry sent before this}}
 
  |-
 
  |-
  | Y
+
  | Hashed seed
  | Float
+
  | Long
  | Y position of the particle
+
  | First 8 bytes of the SHA-256 hash of the world's seed.
 
  |-
 
  |-
  | Z
+
  | Max Players
  | Float
+
  | Unsigned Byte
  | Z position of the particle
+
  | Was once used by the client to draw the player list, but now is ignored
|-
+
  |- {{Removed}}
| Offset X
+
  | Level Type
| Float
+
  | String Enum (16)
| This is added to the X position after being multiplied by random.nextGaussian()
+
  | default, flat, largeBiomes, amplified, customized, buffet, default_1_1
  |-
 
  | 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
+
  | View Distance
| Float
 
| The data of each particle
 
|-
 
| Particle Count
 
| Int
 
| The number of particles to create
 
|-
 
| Data
 
| {{Change|Array of VarInt|Varies}}
 
| {{Change|Length depends on particle. "iconcrack" has length of 2, "blockcrack", "blockdust", and "fallingdust" have lengths of 1, the rest have 0.|Type of data varies based off of the particle.  For "iconcrack", it is a [[Slot]].  For "blockcrack", "blockdust", and "fallingdust", it is a block state encoded as a VarInt that is an index within the global palette.}}
 
|}
 
 
 
==== Craft Recipe Response ====
 
 
 
Response to the serverbound packet ([[#Craft Recipe Request|Craft Recipe Request]]), with the same recipe ID.  Appears to be used to notify the UI.
 
 
 
{| class="wikitable"
 
! Packet ID
 
! State
 
! Bound To
 
! Field Name
 
! Field Type
 
! Notes
 
|-
 
|rowspan="2"| {{Change|0x2B|0x2C}}
 
|rowspan="2"| Play
 
|rowspan="2"| Client
 
| Window ID
 
| Byte
 
|
 
|-
 
| Recipe
 
| {{Change|VarInt|Identifer}}
 
| A recipe ID
 
|}
 
 
 
 
 
==== Unlock Recipes ====
 
 
 
{| class="wikitable"
 
! Packet ID
 
! State
 
! Bound To
 
! Field Name
 
! Field Type
 
! Notes
 
|-
 
|rowspan="8"| {{Change|0x31|0x32}}
 
|rowspan="8"| Play
 
|rowspan="8"| Client
 
|-
 
| Action
 
 
  | VarInt
 
  | VarInt
  | 0: init, 1: add, 2: remove
+
  | Render distance (2-32)
 
  |-
 
  |-
  | Crafting Book Open
+
  | Reduced Debug Info
 
  | Boolean
 
  | Boolean
  | If true, then the crafting book will be open when the player opens its inventory.
+
  | If true, a Notchian client shows reduced information on the {{Minecraft Wiki|debug screen}}.  For servers in development, this should almost always be false.
 
  |-
 
  |-
  | Filtering Craftable
+
  | Enable respawn screen
 +
| Boolean
 +
| Set to false when the doImmediateRespawn gamerule is true
 +
|- {{Added}}
 +
| Is Debug
 +
| Boolean
 +
| True if the world is a {{Minecraft Wiki|debug mode}} world; debug mode worlds cannot be modified and have predefined blocks
 +
|- {{Added}}
 +
| Is Flat
 
  | Boolean
 
  | Boolean
  | If true, then the filtering option is active when the players opens its inventory.
+
  | True if the world is a {{Minecraft Wiki|superflat}} world; flat worlds have different void fog and a horizon at y=0 instead of y=63
|-
 
| Array size 1
 
| VarInt
 
| Number of elements in the following array
 
|-
 
| Recipe IDs
 
| Array of {{Change|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 {{Change|VarInt|Identifier}}, only present if mode is 0 (init)
 
|
 
 
  |}
 
  |}
Action:
+
Example of Dimension codec CompoundTag sent by the server:  
* 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?
+
    ListTag (Type: CompoundTag) "dimension":
* 1 (add) = All the recipes in the list are added and their icon will be shown in the notification.
+
        CompoundTag:
* 2 (remove) = Remove all the recipes in the list. This allows them to re-displayed when they are readded.
+
            StringTag "key" value: 'minecraft:overworld'
 
+
            StringTag "element" value: 'minecraft:overworld'
==== Scoreboard Objective ====
+
        CompoundTag:
 +
            StringTag "key" value: 'minecraft:the_nether'
 +
            StringTag "element" value: 'minecraft:the_nether'
 +
        CompoundTag:
 +
            StringTag "key" value: 'minecraft:the_end'
 +
            StringTag "element" value: 'minecraft:the_end'
  
This is sent to the client when it should create a new {{Minecraft Wiki|scoreboard}} objective or remove one.
+
==== Respawn ====
 
 
{| class="wikitable"
 
! Packet ID
 
! State
 
! Bound To
 
! Field Name
 
! Field Type
 
! Notes
 
|-
 
|rowspan="4"| {{Change|0x42|0x43}}
 
|rowspan="4"| Play
 
|rowspan="4"| 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 {{change|String|VarInt Enum}}
 
| Only if mode is 0 or 2. {{change|“integer” or “hearts”|0 = "integer", 1 = "hearts"}}
 
|}
 
  
==== Stop Sound ====
+
To change the player's dimension (overworld/nether/end), send them a respawn packet with the appropriate dimension, followed by prechunks/chunks for the new dimension, and finally a position and look packet. You do not need to unload chunks, the client will do it automatically.
  
 
{| class="wikitable"
 
{| class="wikitable"
Line 943: Line 474:
 
  ! Notes
 
  ! Notes
 
  |-
 
  |-
  |rowspan="7"| 0x4A
+
  |rowspan="7"| 0x3B
 
  |rowspan="7"| Play
 
  |rowspan="7"| Play
 
  |rowspan="7"| Client
 
  |rowspan="7"| Client
  | Flags
+
  | Dimension
  | Byte
+
  | {{change|Int Enum|Identifier}}
  | Controls which fields are present.
+
  | {{change|-1: The Nether, 0: The Overworld, 1: The End|Valid dimensions are defined per dimension registry sent in [[#Join Game|Join Game]]}}
 
  |-
 
  |-
  | Source
+
  | Hashed seed
  | Optional VarInt enum
+
  | Long
  | Only if flags is 3 or 1 (bit mask 0x1).  See below.  If not present, then sounds from all sources are cleared.
+
  | First 8 bytes of the SHA-256 hash of the world's seed.
 
  |-
 
  |-
  | Sound
+
  | Gamemode
  | Optional Identifier
+
  | Unsigned Byte
  | Only if flags is 2 or 3 (bit mask 0x2). A sound effect name, see [[#Named Sound Effect|Named Sound Effect]].  If not present, then all sounds are cleared.
+
  | 0: survival, 1: creative, 2: adventure, 3: spectator. The hardcore flag is not included
 +
|- {{Removed}}
 +
| Level Type
 +
| String (16)
 +
  | Same as [[#Join Game|Join Game]]
 +
|- {{Added}}
 +
| Is Debug
 +
| Boolean
 +
| True if the world is a {{Minecraft Wiki|debug mode}} world; debug mode worlds cannot be modified and have predefined blocks
 +
|- {{Added}}
 +
| Is Flat
 +
| Boolean
 +
| True if the world is a {{Minecraft Wiki|superflat}} world; flat worlds have different void fog and a horizon at y=0 instead of y=63
 +
|- {{added}}
 +
| Copy metadata
 +
| Boolean
 +
| If false, metadata is reset on the respawned player entitySet to true for dimension changes (including the dimension change triggered by sending client status perform respawn to exit the end poem/credits), and false for normal respawns.
 
  |}
 
  |}
  
Categories:
+
{{Warning2|Avoid changing player's dimension to same dimension they were already in unless they are dead. If you change the dimension to one they are already in, weird bugs can occur, such as the player being unable to attack other players in new world (until they die and respawn).
  
{| class="wikitable"
+
If you must respawn a player in the same dimension without killing them, send two respawn packets, one to a different world and then another to the world you want. You do not need to complete the first respawn; it only matters that you send two packets.}}
! Name !! Value
+
 
|-
+
==== Entity Properties ====
| master || 0
 
|-
 
| music || 1
 
|-
 
| record || 2
 
|-
 
| weather || 3
 
|-
 
| block || 4
 
|-
 
| hostile || 5
 
|-
 
| neutral || 6
 
|-
 
| player || 7
 
|-
 
| ambient || 8
 
|-
 
| voice || 9
 
|}
 
  
==== Declare Recipes ====
+
Sets {{Minecraft Wiki|Attribute|attributes}} on the given entity.
  
 
{| class="wikitable"
 
{| class="wikitable"
Line 995: Line 522:
 
  ! Notes
 
  ! Notes
 
  |-
 
  |-
  |rowspan="4"| 0x52
+
  |rowspan="6"| 0x59
  |rowspan="4"| Play
+
  |rowspan="6"| Play
  |rowspan="4"| Client
+
  |rowspan="6"| Client
  |colspan="2"| Num Recipes
+
  |colspan="2"| Entity ID
 
  |colspan="2"| VarInt
 
  |colspan="2"| VarInt
  | Length of the following array
+
  |  
 
  |-
 
  |-
  |rowspan="3"| Recipe
+
|colspan="2"| Number Of Properties
  | Recipe ID
+
|colspan="2"| Int
  |rowspan="3"| Array
+
| Number of elements in the following array
  | Identifier
+
|-
  |
+
  |rowspan="4"| Property
 +
  | Key
 +
  |rowspan="4"| Array
 +
  | {{Change|String (64)|Identifier}}
 +
| See below
 +
|-
 +
| Value
 +
| Double
 +
  | See below
 
  |-
 
  |-
  | Type
+
  | Number Of Modifiers
  | String
+
  | VarInt
  | The recipe type, see below
+
  | Number of elements in the following array
 
  |-
 
  |-
  | Data
+
  | Modifiers
  | Optional, varies
+
  | Array of Modifier Data
  | Additional data for the recipe. For some types, there will be no data.
+
  | See {{Minecraft Wiki|Attribute#Modifiers}}. Modifier Data defined below.
 
  |}
 
  |}
  
Recipe types:
+
Known Key values (see also {{Minecraft Wiki|Attribute#Modifiers}}):
  
 
{| class="wikitable"
 
{| class="wikitable"
! Type
 
! Description
 
! Data
 
 
  |-
 
  |-
  | <code>crafting_shapeless</code>
+
  ! Key
  | Shapeless crafting recipe.  All items in the ingredient list must be present, but in any order/slot.
+
  ! Default
  | As follows:
+
  ! Min
  {| class="wikitable"
+
! Max
    ! Name
+
! Label
    ! Type
 
    ! Description
 
    |-
 
    | Group
 
    | String
 
    | Used to group similar recipes together in the recipe book.  Tag is present in recipe JSON.
 
    |-
 
    | Ingredient count
 
    | VarInt
 
    | Length of the following array
 
    |-
 
    | Ingredients
 
    | Array of Ingredient
 
    |
 
    |-
 
    | Result
 
    | [[Slot]]
 
    |
 
    |}
 
 
  |-
 
  |-
  | <code>crafting_shaped</code>
+
  | {{change|generic.maxHealth|generic.max_health}}
  | Shaped crafting recipe. All items must be present in the same pattern (which may be flipped horizontally or translated)
+
  | 20.0
  | As follows:
+
  | 0.0
  {| class="wikitable"
+
| 1024.0
    ! Name
+
  | Max Health
    ! 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]]
 
    |
 
    |}
 
 
  |-
 
  |-
  | <code>crafting_special_armordye</code>
+
  | {{change|generic.followRange|generic.follow_range}}
  | Recipe for dying leather armor
+
| 32.0
  | None
+
| 0.0
 +
  | 2048.0
 +
  | Follow Range
 
  |-
 
  |-
  | <code>crafting_special_bookcloning</code>
+
  | {{change|generic.knockbackResistance|generic.knockback_resistance}}
  | Recipe for copying contents of written books
+
| 0.0
  | None
+
| 0.0
 +
  | 1.0
 +
  | Knockback Resistance
 
  |-
 
  |-
  | <code>crafting_special_mapcloning</code>
+
  | {{change|generic.movementSpeed|generic.movement_speed}}
  | Recipe for copying maps
+
| 0.7
  | None
+
| 0.0
 +
  | 1024.0
 +
  | Movement Speed
 
  |-
 
  |-
  | <code>crafting_special_mapextending</code>
+
  | {{change|generic.attackDamage|generic.attack_damage}}
  | Recipe for adding paper to maps
+
| 2.0
  | None
+
| 0.0
 +
  | 2048.0
 +
  | Attack Damage
 
  |-
 
  |-
  | <code>crafting_special_firework_rocket</code>
+
  | {{change|generic.attackSpeed|generic.attack_speed}}
  | Recipe for making firework rockets
+
| 4.0
  | None
+
| 0.0
 +
  | 1024.0
 +
  | Attack Speed
 
  |-
 
  |-
  | <code>crafting_special_firework_star</code>
+
  | {{change|generic.flyingSpeed|generic.flying_speed}}
  | Recipe for making firework stars
+
| 0.4
  | None
+
| 0.0
 +
  | 1024.0
 +
  | Flying Speed
 
  |-
 
  |-
  | <code>crafting_special_firework_star_fade</code>
+
  | generic.armor
  | Recipe for making firework stars fade between multiple colors
+
  | 0.0
  | None
+
  | 0.0
 +
| 30.0
 +
| Armor
 
  |-
 
  |-
  | <code>crafting_special_repairitem</code>
+
  | {{change|generic.armorToughness|generic.armor_toughness}}
  | Recipe for repairing items via crafting
+
| 0.0
  | None
+
| 0.0
 +
  | 20.0
 +
  | Armor Toughness
 
  |-
 
  |-
  | <code>crafting_special_tippedarrow</code>
+
  | {{change|generic.attackKnockback|generic.attack_knockback}}
  | Recipe for crafting tipped arrows
+
| 0.0
  | None
+
| 0.0
 +
  | 5.0
 +
  | &mdash;
 
  |-
 
  |-
  | <code>crafting_special_bannerduplicate</code>
+
  | generic.luck
  | Recipe for copying banner patterns
+
  | 0.0
  | None
+
  | -1024.0
 +
| 1024.0
 +
| Luck
 
  |-
 
  |-
  | <code>crafting_special_banneraddpattern</code>
+
  | {{change|horse.jumpStrength|horse.jump_strength}}
  | Recipe for adding patterns to banners
+
| 0.7
  | None
+
| 0.0
 +
  | 2.0
 +
  | Jump Strength
 
  |-
 
  |-
  | <code>crafting_special_shielddecoration</code>
+
  | {{change|zombie.spawnReinforcements|zombie.spawn_reinforcements}}
  | Recipe for applying a banner's pattern to a shield
+
| 0.0
  | None
+
| 0.0
 +
  | 1.0
 +
  | Spawn Reinforcements Chance
 
  |-
 
  |-
  | <code>crafting_special_shulkerboxcoloring</code>
+
  | generic.reachDistance
  | Recipe for recoloring a shulker box
+
  | 5.0
  | None
+
  | 0.0
  |}
+
  | 1024.0
 
+
| Player Reach Distance (Forge only)
Ingredient is defined as:
 
 
 
{| class="wikitable"
 
! Name
 
! Type
 
! Description
 
 
  |-
 
  |-
  | Count
+
  | forge.swimSpeed
  | VarInt
+
  | 1.0
  | Length of the following array
+
  | 0.0
  |-
+
  | 1024.0
| Items
+
  | Swimming Speed (Forge only)
  | Array of [[Slot]]
 
| Any item in this array may be used for the recipe.  The count of each item should be 1.
 
 
  |}
 
  |}
  
==== Tags ====
+
Unknown attributes will cause a game crash ([https://bugs.mojang.com/browse/MC-150405 MC-150405]) due to the default minimum being larger than the default value.
  
{{Warning|This packet MUST be send, even if it's empty, not doing so can crash the client (e.g. when clicking a fuel slot in a furnace).}}
+
''Modifier Data'' structure:
  
 
{| class="wikitable"
 
{| class="wikitable"
  ! Packet ID
+
  |-
! State
 
! Bound To
 
 
  ! Field Name
 
  ! Field Name
 
  ! Field Type
 
  ! Field Type
 
  ! Notes
 
  ! Notes
 
  |-
 
  |-
  |rowspan="2"| 0x53
+
  | UUID
  |rowspan="2"| Play
+
| UUID
  |rowspan="2"| Client
+
  |  
  | Block Tags
+
  |-
  | (See below)
+
  | Amount
  | IDs are block IDs
+
  | Double
 +
  | May be positive or negative
 
  |-
 
  |-
  | Item Tags
+
  | Operation
  | (See below)
+
  | Byte
  | IDs are item IDs
+
  | See below
 
  |}
 
  |}
  
Tags look like:
+
The operation controls how the base value of the modifier is changed.
  
{| class="wikitable"
+
* 0: Add/subtract amount
!colspan="2"| Field Name
+
* 1: Add/subtract amount percent of the current value
!colspan="2"| Field Type
+
* 2: Multiply by amount percent
! Notes
+
 
|-
+
All of the 0's are applied first, and then the 1's, and then the 2's.
|colspan="2"| Length
 
|colspan="2"| VarInt
 
| Length of the following array
 
|-
 
|rowspan="3"| Tags
 
| Tag name
 
|rowspan="3"| Array
 
| Identifier
 
|
 
|-
 
| Count
 
| VarInt
 
| Length of the following array
 
|-
 
| Entries
 
| Array of VarInt
 
| Numeric ID of the block/item.
 
|}
 
  
 
=== Serverbound ===
 
=== Serverbound ===
  
==== Tab-Complete (serverbound) ====
+
==== Generate Structure ====
 
 
{{Need Info|This is most definitely no longer an accurate description of this packet}}
 
  
Sent when the user presses ''tab'' while writing text.
+
Sent when Generate is pressed on the {{Minecraft Wiki|Jigsaw Block}} interface.
  
{| class="wikitable"
+
{| class="wikitable" {{added}}
 
  ! Packet ID
 
  ! Packet ID
 
  ! State
 
  ! State
Line 1,213: Line 698:
 
  ! Notes
 
  ! Notes
 
  |-
 
  |-
  |rowspan="5"| {{Change|0x01|0x04}}
+
  |rowspan="2"| 0x0F
  |rowspan="5"| Play
+
  |rowspan="2"| Play
  |rowspan="5"| Server
+
  |rowspan="2"| Server
  |style="background-color: #d9ead3;"| Transaction Id
+
  | Location
  |style="background-color: #d9ead3;"| VarInt
+
  | Position
  |style="background-color: #d9ead3;"| The id received in the tab completion request packet, must match or the client will ignore this packet.
+
  | Block entity location
 
  |-
 
  |-
  | Text
+
  | Levels
  | String ({{change|32767|256}})
+
  | VarInt
  | All text behind the cursor without the <code>/</code> (e.g. to the left of the cursor in left-to-right languages like English)
+
  | Value of the levels slider/max depth to generate
|- style="background-color: #f4cccc; text-decoration: line-through;"
 
| Assume Command
 
| Boolean
 
| If true, the server will parse Text as a command even if it doesn't start with a <code>/</code>. Used in the command block GUI.
 
|- style="background-color: #f4cccc; text-decoration: line-through;"
 
| Has Position
 
| Boolean
 
|
 
|- style="background-color: #f4cccc; text-decoration: line-through;"
 
| Looked At Block
 
| Optional Position
 
| The position of the block being looked at. Only sent if Has Position is true.
 
 
  |}
 
  |}
  
==== Craft Recipe Request ====
+
==== Update Jigsaw Block ====
 
 
A replacement for [[Protocol#Prepare Crafting Grid|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).
+
Sent when Done is pressed on the {{Minecraft Wiki|Jigsaw Block}} interface.
  
 
{| class="wikitable"
 
{| class="wikitable"
Line 1,251: Line 722:
 
  ! Notes
 
  ! Notes
 
  |-
 
  |-
  |rowspan="3"| 0x12
+
  |rowspan="7"| {{Change|0x27|0x28}}
  |rowspan="3"| Play
+
  |rowspan="7"| Play
  |rowspan="3"| Server
+
  |rowspan="7"| Server
  | Window ID
+
  | Location
  | Byte
+
| Position
  |
+
| Block entity location
 +
|- {{Removed}}
 +
| Attachment type
 +
| Identifier
 +
|
 +
|- {{Added}}
 +
| Name
 +
| Identifier
 +
|
 +
|- {{Added}}
 +
| Target
 +
| Identifier
 +
|
 +
|-
 +
| {{Change|Target pool|Pool}}
 +
  | Identifier
 +
  |  
 
  |-
 
  |-
  | Recipe
+
  | Final state
  | {{Change|VarInt|Identifier}}
+
  | String
  | A recipe ID
+
  | "Turns into" on the GUI, <code>final_state</code> in NBT
  |-
+
  |- {{Added}}
  | Make all
+
  | Joint type
  | Boolean
+
  | String
  | Affects the amount of items processed; true if shift is down when clicked
+
  | <code>rollable</code> if the attached piece can be rotated, else <code>aligned</code>
 
  |}
 
  |}
 
  
 
== Handshaking ==
 
== Handshaking ==
Line 1,293: Line 779:
 
  | Protocol Version
 
  | Protocol Version
 
  | VarInt
 
  | VarInt
  | See [[protocol version numbers]] (currently {{change|340|351}})
+
  | See [[protocol version numbers]] (currently {{change|578|718}})
 
  |-
 
  |-
 
  | Server Address
 
  | Server Address
 
  | String
 
  | 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.
+
  | Hostname or IP, e.g. localhost or 127.0.0.1, that was used to connect. The Notchian server does not use this information. Note that SRV records are a complete redirect, e.g. if _minecraft._tcp.example.com points to mc.example.org, users connecting to example.com will provide mc.example.org as server address in addition to connecting to it.
 
  |-  
 
  |-  
 
  | Server Port
 
  | Server Port
Line 1,322: Line 808:
 
=== Clientbound ===
 
=== Clientbound ===
  
No changes so far.
+
==== Login Success ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x02
 +
|rowspan="2"| Login
 +
|rowspan="2"| Client
 +
| UUID
 +
| {{Change|String (36)|UUID}}
 +
| {{Change|Unlike in other packets, this field contains the UUID as a string with hyphens}}.
 +
|-
 +
| Username
 +
| String (16)
 +
|
 +
|}
 +
 
 +
This packet switches the connection state to [[#Play|play]].
  
 
=== Serverbound ===
 
=== Serverbound ===

Latest revision as of 04:52, 23 May 2020

This page documents the changes from the last stable Minecraft release (currently 1.15.2, protocol 578) to the current pre-release (currently 20w21a, protocol 718). 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

The UUID type is now also sometimes encoded by the Notchian server as an array of four 32-bit integers, from most significant to least significant (matching the new format used on entity NBT). This representation is identical to using 16 bytes, two 64-bit integers, or one 128-bit integers.

Packets

ID Packet name Documentation
Handshaking serverbound
0x00 Handshake Current Pre
Play clientbound
0x0F Chat Message (clientbound) Current Pre
0x22 Chunk Data Current Pre
0x26 Join Game Current Pre
0x3B Respawn Current Pre
0x4E 0x43 Spawn Position Current (unchanged)
0x43 0x44 Display Scoreboard Current (unchanged)
0x44 0x45 Entity Metadata Current (unchanged)
0x45 0x46 Attach Entity Current (unchanged)
0x46 0x47 Entity Velocity Current (unchanged)
0x47 0x48 Entity Equipment Current (unchanged)
0x48 0x49 Set Experience Current (unchanged)
0x49 0x4A Update Health Current (unchanged)
0x4A 0x4B Scoreboard Objective Current (unchanged)
0x4B 0x4C Set Passengers Current (unchanged)
0x4C 0x4D Teams Current (unchanged)
0x4D 0x4E Update Score Current (unchanged)
0x59 Entity Properties Current Pre
Play serverbound
0x0F Generate Structure Pre
0x0F 0x10 Keep Alive (serverbound) Current (unchanged)
0x10 0x11 Lock Difficulty Current (unchanged)
0x11 0x12 Player Position Current (unchanged)
0x12 0x13 Player Position And Rotation (serverbound) Current (unchanged)
0x13 0x14 Player Rotation Current (unchanged)
0x14 0x15 Player Movement Current (unchanged)
0x15 0x16 Vehicle Move (serverbound) Current (unchanged)
0x16 0x17 Steer Boat Current (unchanged)
0x17 0x18 Pick Item Current (unchanged)
0x18 0x19 Craft Recipe Request Current (unchanged)
0x19 0x1A Player Abilities (serverbound) Current (unchanged)
0x1A 0x1B Player Digging Current (unchanged)
0x1B 0x1C Entity Action Current (unchanged)
0x1C 0x1D Steer Vehicle Current (unchanged)
0x1D 0x1E Recipe Book Data Current (unchanged)
0x1E 0x1F Name Item Current (unchanged)
0x1F 0x20 Resource Pack Status Current (unchanged)
0x20 0x21 Advancement Tab Current (unchanged)
0x21 0x22 Select Trade Current (unchanged)
0x22 0x23 Set Beacon Effect Current (unchanged)
0x23 0x24 Held Item Change (serverbound) Current (unchanged)
0x24 0x25 Update Command Block Current (unchanged)
0x25 0x26 Update Command Block Minecart Current (unchanged)
0x26 0x27 Creative Inventory Action Current (unchanged)
0x27 0x28 Update Jigsaw Block Current Pre
0x28 0x29 Update Structure Block Current (unchanged)
0x29 0x2A Update Sign Current (unchanged)
0x2A 0x2B Animation (serverbound) Current (unchanged)
0x2B 0x2C Spectate Current (unchanged)
0x2C 0x2D Player Block Placement Current (unchanged)
0x2D 0x2E Use Item Current (unchanged)
Login clientbound
0x02 Login Success Current Pre

New/modified data types

No changes so far.

Entity Metadata

FishingHook

Extends Entity.

Index Type Meaning Default
7 VarInt Hooked entity id + 1, or 0 if there is no hooked entity 0
8 Boolean Is catchable False

Abstract Arrow

Extends Entity.

Abstract base class for Tipped Arrow (which is used for regular arrows as well as tipped ones) and Spectral Arrow.

Index Type Meaning Default
7 Byte Bit mask Meaning 0
0x01 Is critical
0x02 Is noclip (used by loyalty tridents when returning)
8 OptUUID Unused Empty
9 8 Byte Peircing level 0

Tipped Arrow

Extends Abstract Arrow.

Used for both tipped and regular arrows. If not tipped, then color is set to -1 and no tipped arrow particles are used.

Index Type Meaning Default
10 9 VarInt Color (-1 for no particles) -1

Spectral Arrow

Extends Abstract Arrow.

No additional metadata.

Trident

Extends Abstract Arrow.

Index Type Meaning Default
10 9 VarInt Loyalty level (enchantment) 0
11 10 Boolean Has enchantment glint False

Strider

Extends Animal.

Index Type Meaning Default
16 VarInt Total time to "boost" with warped fungus on a stick for 0
17 Boolean Should display name tag (true unless riding a vehicle or on or in a block tagged with strider_warm_blocks (default: lava)) false
18 Boolean Has saddle false

Hoglin

Extends Animal.

Index Type Meaning Default
16 Boolean Is immune to zombification false

Zoglin

Extends Monster.

Index Type Meaning Default
15 Boolean Is baby false

Piglin

Extends Monster.

Index Type Meaning Default
15 Boolean Is baby false
16 Boolean Is immune to zombification false
17 Boolean Is charging crossbow false

Zombie Pigman Zombified Piglin

Extends Zombie.

No additional metadata.

Block Actions

No changes so far.

Inventories

No changes so far.

Plugin Channels

No changes so far.

Play

Clientbound

Chat Message (clientbound)

Identifying the difference between Chat/System Message is important as it helps respect the user's chat visibility options. See processing chat for more info about these positions.

Warning.png Game info accepts json formatting but does not display it, although the deprecated §-based formatting works. This is not an issue when using the Title packet, so prefer that packet for displaying information in that slot. See MC-119145 for more information.

Packet ID State Bound To Field Name Field Type Notes
0x0F Play Client JSON Data Chat Limited to 32767 bytes
Position Byte 0: chat (chat box), 1: system message (chat box), 2: game info (above hotbar).
Sender UUID Used by the Notchian client for the disableChat launch option. Setting both longs to 0 will always display the message regardless of the setting.

Chunk Data

Main article: Chunk Format
See also: #Unload Chunk
Huh.png The following information needs to be added to this page:
How do biomes work now? The biome change happened at the same time as the seed change, but it's not clear how/if biomes could be computed given that it's not the actual seed... (/r/mojira discussion which notes that it seems to be some kind of interpolation, and 3D biomes are only used in the nether)

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).

Packet ID State Bound To Field Name Field Type Notes
0x22 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)
Full chunk 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).
Heightmaps NBT Compound containing one long array named MOTION_BLOCKING, which is a heightmap for the highest solid block at each position in the chunk (as a compacted long array with 256 entries at 9 bits per entry totaling 36 longs). The Notchian server also adds a WORLD_SURFACE long array, the purpose of which is unknown, but it's not required for the chunk to be accepted.
Biomes Optional array of Integer 1024 biome IDs, ordered by x then z then y, in 4×4×4 blocks. Not present if full chunk is false.
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.

Note that the Notchian client requires an Update View Position packet when it crosses a chunk border, otherwise it'll only display render distance + 2 chunks around the chunk it spawned in.

The compacted array format has been adjusted so that individual entries no longer span across multiple longs, affecting the main data array and heightmaps.

Join Game

See Protocol Encryption for information on logging in.

Packet ID State Bound To Field Name Field Type Notes
0x26 Play Client Entity ID Int The player's Entity ID (EID)
Gamemode Unsigned Byte 0: Survival, 1: Creative, 2: Adventure, 3: Spectator. Bit 3 (0x8) is the hardcore flag.
Dimension Codec NBT Tag Compound This CompoundTag contains a ListTag named "dimension". The ListTag should contain CompoundTags with named StringTags "key" and "element". The full extent of these is still unknown, but the tag represents a dimension registry. See below for the vanilla default.
Dimension Int Enum Identifier -1: The Nether, 0: The Overworld, 1: The End Valid dimensions are defined per dimension registry sent before this
Hashed seed Long First 8 bytes of the SHA-256 hash of the world's seed.
Max Players Unsigned Byte Was once used by the client to draw the player list, but now is ignored
Level Type String Enum (16) default, flat, largeBiomes, amplified, customized, buffet, default_1_1
View Distance VarInt Render distance (2-32)
Reduced Debug Info Boolean If true, a Notchian client shows reduced information on the debug screen. For servers in development, this should almost always be false.
Enable respawn screen Boolean Set to false when the doImmediateRespawn gamerule is true
Is Debug Boolean True if the world is a debug mode world; debug mode worlds cannot be modified and have predefined blocks
Is Flat Boolean True if the world is a superflat world; flat worlds have different void fog and a horizon at y=0 instead of y=63

Example of Dimension codec CompoundTag sent by the server:

   ListTag (Type: CompoundTag) "dimension":
       CompoundTag: 
           StringTag "key" value: 'minecraft:overworld'
           StringTag "element" value: 'minecraft:overworld'
       CompoundTag: 
           StringTag "key" value: 'minecraft:the_nether'
           StringTag "element" value: 'minecraft:the_nether'
       CompoundTag: 
           StringTag "key" value: 'minecraft:the_end'
           StringTag "element" value: 'minecraft:the_end'

Respawn

To change the player's dimension (overworld/nether/end), send them a respawn packet with the appropriate dimension, followed by prechunks/chunks for the new dimension, and finally a position and look packet. You do not need to unload chunks, the client will do it automatically.

Packet ID State Bound To Field Name Field Type Notes
0x3B Play Client Dimension Int Enum Identifier -1: The Nether, 0: The Overworld, 1: The End Valid dimensions are defined per dimension registry sent in Join Game
Hashed seed Long First 8 bytes of the SHA-256 hash of the world's seed.
Gamemode Unsigned Byte 0: survival, 1: creative, 2: adventure, 3: spectator. The hardcore flag is not included
Level Type String (16) Same as Join Game
Is Debug Boolean True if the world is a debug mode world; debug mode worlds cannot be modified and have predefined blocks
Is Flat Boolean True if the world is a superflat world; flat worlds have different void fog and a horizon at y=0 instead of y=63
Copy metadata Boolean If false, metadata is reset on the respawned player entity. Set to true for dimension changes (including the dimension change triggered by sending client status perform respawn to exit the end poem/credits), and false for normal respawns.

Warning.png Avoid changing player's dimension to same dimension they were already in unless they are dead. If you change the dimension to one they are already in, weird bugs can occur, such as the player being unable to attack other players in new world (until they die and respawn).

If you must respawn a player in the same dimension without killing them, send two respawn packets, one to a different world and then another to the world you want. You do not need to complete the first respawn; it only matters that you send two packets.

Entity Properties

Sets attributes on the given entity.

Packet ID State Bound To Field Name Field Type Notes
0x59 Play Client Entity ID VarInt
Number Of Properties Int Number of elements in the following array
Property Key Array String (64) Identifier See below
Value Double See below
Number Of Modifiers VarInt Number of elements in the following array
Modifiers Array of Modifier Data See Attribute#Modifiers. Modifier Data defined below.

Known Key values (see also Attribute#Modifiers):

Key Default Min Max Label
generic.maxHealth generic.max_health 20.0 0.0 1024.0 Max Health
generic.followRange generic.follow_range 32.0 0.0 2048.0 Follow Range
generic.knockbackResistance generic.knockback_resistance 0.0 0.0 1.0 Knockback Resistance
generic.movementSpeed generic.movement_speed 0.7 0.0 1024.0 Movement Speed
generic.attackDamage generic.attack_damage 2.0 0.0 2048.0 Attack Damage
generic.attackSpeed generic.attack_speed 4.0 0.0 1024.0 Attack Speed
generic.flyingSpeed generic.flying_speed 0.4 0.0 1024.0 Flying Speed
generic.armor 0.0 0.0 30.0 Armor
generic.armorToughness generic.armor_toughness 0.0 0.0 20.0 Armor Toughness
generic.attackKnockback generic.attack_knockback 0.0 0.0 5.0
generic.luck 0.0 -1024.0 1024.0 Luck
horse.jumpStrength horse.jump_strength 0.7 0.0 2.0 Jump Strength
zombie.spawnReinforcements zombie.spawn_reinforcements 0.0 0.0 1.0 Spawn Reinforcements Chance
generic.reachDistance 5.0 0.0 1024.0 Player Reach Distance (Forge only)
forge.swimSpeed 1.0 0.0 1024.0 Swimming Speed (Forge only)

Unknown attributes will cause a game crash (MC-150405) due to the default minimum being larger than the default value.

Modifier Data structure:

Field Name Field Type Notes
UUID UUID
Amount Double May be positive or negative
Operation Byte See below

The operation controls how the base value of the modifier is changed.

  • 0: Add/subtract amount
  • 1: Add/subtract amount percent of the current value
  • 2: Multiply by amount percent

All of the 0's are applied first, and then the 1's, and then the 2's.

Serverbound

Generate Structure

Sent when Generate is pressed on the Jigsaw Block interface.

Packet ID State Bound To Field Name Field Type Notes
0x0F Play Server Location Position Block entity location
Levels VarInt Value of the levels slider/max depth to generate

Update Jigsaw Block

Sent when Done is pressed on the Jigsaw Block interface.

Packet ID State Bound To Field Name Field Type Notes
0x27 0x28 Play Server Location Position Block entity location
Attachment type Identifier
Name Identifier
Target Identifier
Target pool Pool Identifier
Final state String "Turns into" on the GUI, final_state in NBT
Joint type String rollable if the attached piece can be rotated, else aligned

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 578 718)
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. Note that SRV records are a complete redirect, e.g. if _minecraft._tcp.example.com points to mc.example.org, users connecting to example.com will provide mc.example.org as server address in addition to connecting to it.
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

Login Success

Packet ID State Bound To Field Name Field Type Notes
0x02 Login Client UUID String (36) UUID Unlike in other packets, this field contains the UUID as a string with hyphens.
Username String (16)

This packet switches the connection state to play.

Serverbound

No changes so far.