Difference between revisions of "Protocol"

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This page presents a dissection of the new [http://minecraft.net/game/ Minecraft Beta] protocol. Credit goes to the Great Old Ones, and the citizens of [irc://irc.freenode.net/#mcdevs <nowiki>#mcdevs</nowiki>] who helped by providing packet dumps and insight. If you're having trouble, check out the [[Protocol_FAQ|FAQ]].
+
{{Box
 +
  |BORDER = #9999FF
 +
  |BACKGROUND = #99CCFF
 +
  |WIDTH = 100%
 +
  |ICON =
 +
  |HEADING = Heads up!
 +
  |CONTENT = This article is about the protocol for the latest '''stable''' release of Minecraft '''Java Edition''' ([[Protocol version numbers|1.15.2, protocol 578]]). For the Java Edition pre-releases, see [[Pre-release protocol]]. For the incomplete Bedrock Edition docs, see [[Bedrock Protocol]]. For the old Pocket Edition, see [[Pocket Edition Protocol Documentation]].
 +
}}
  
'''Note:''' While you may use the contents of this page without restriction to create servers, clients, bots, etc… you still need to provide the attribution above if you copy any of the contents of this page for publication elsewhere.
+
This page presents a dissection of the current '''[https://minecraft.net/ Minecraft] protocol'''.
  
== Data Types ==
+
If you're having trouble, check out the [[Protocol FAQ|FAQ]] or ask for help in the IRC channel [ircs://chat.freenode.net:6697/mcdevs #mcdevs on chat.freenode.net] ([http://wiki.vg/MCDevs More Information]).
  
All types in Java (and as such Minecraft) are [http://en.wikipedia.org/wiki/Endianness#Big-endian big-endian], that is, the most significant byte comes first. The majority of everyday computers are little endian, and using most programming languages will require converting big endian values to little endian.
+
'''Note:''' While you may use the contents of this page without restriction to create servers, clients, bots, etc… you still need to provide attribution to #mcdevs if you copy any of the contents of this page for publication elsewhere.
  
These data formats are identical to those provided by the Java classes [http://download.oracle.com/javase/1.4.2/docs/api/java/io/DataInputStream.html DataInputStream] and [http://download.oracle.com/javase/1.4.2/docs/api/java/io/DataOutputStream.html DataOutputStream].
+
The changes between versions may be viewed at [[Protocol History]].
 +
 
 +
== Definitions ==
 +
 
 +
The Minecraft server accepts connections from TCP clients and communicates with them using ''packets''. A packet is a sequence of bytes sent over the TCP connection. The meaning of a packet depends both on its packet ID and the current state of the connection. The initial state of each connection is [[#Handshaking|Handshaking]], and state is switched using the packets [[#Handshake|Handshake]] and [[#Login Success|Login Success]].
 +
 
 +
=== Data types ===
 +
 
 +
{{:Data types}} <!-- Transcluded contents of Data types article in here — go to that page if you want to edit it -->
 +
 
 +
=== Other definitions ===
 +
 
 +
{| class="wikitable"
 +
|-
 +
! Term
 +
! Definition
 +
|-
 +
| Player
 +
| When used in the singular, Player always refers to the client connected to the server.
 +
|-
 +
| Entity
 +
| Entity refers to any item, player, mob, minecart or boat etc. See {{Minecraft Wiki|Entity|the Minecraft Wiki article}} for a full list.
 +
|-
 +
| EID
 +
| An EID — or Entity ID — is a 4-byte sequence used to identify a specific entity. An entity's EID is unique on the entire server.
 +
|-
 +
| XYZ
 +
| In this document, the axis names are the same as those shown in the debug screen (F3). Y points upwards, X points east, and Z points south.
 +
|-
 +
| Meter
 +
| The meter is Minecraft's base unit of length, equal to the length of a vertex of a solid block. The term “block” may be used to mean “meter” or “cubic meter”.
 +
|-
 +
| Global palette
 +
| A table/dictionary/palette mapping nonnegative integers to block states. 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 [https://pokechu22.github.io/Burger/1.15.2.html burger].
 +
 
 +
Alternatively, the vanilla server now includes an option to export the current block state ID mapping, by running <code>java -cp minecraft_server.jar net.minecraft.data.Main --reports</code>.  See [[Data Generators]] for more information.
 +
|-
 +
| Notchian
 +
| The official implementation of vanilla Minecraft as developed and released by Mojang.
 +
|}
 +
 
 +
== Packet format ==
 +
 
 +
=== Without compression ===
 +
 
 +
{| class="wikitable"
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| Length
 +
| VarInt
 +
| Length of Packet ID + Data
 +
|-
 +
| Packet ID
 +
| VarInt
 +
|
 +
|-
 +
| Data
 +
| Byte Array
 +
| Depends on the connection state and packet ID, see the sections below
 +
|}
 +
 
 +
=== With compression ===
 +
 
 +
Once a [[#Set Compression|Set Compression]] packet (with a non-negative threshold) is sent, [[wikipedia:Zlib|zlib]] compression is enabled for all following packets. The format of a packet changes slighty to include the size of the uncompressed packet.
 +
 
 +
{| class=wikitable
 +
! Compressed?
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| No
 +
| Packet Length
 +
| VarInt
 +
| Length of Data Length + compressed length of (Packet ID + Data)
 +
|-
 +
| No
 +
| Data Length
 +
| VarInt
 +
| Length of uncompressed (Packet ID + Data) or 0
 +
|-
 +
|rowspan="2"| Yes
 +
| Packet ID
 +
| VarInt
 +
| zlib compressed packet ID (see the sections below)
 +
|-
 +
| Data
 +
| Byte Array
 +
| zlib compressed packet data (see the sections below)
 +
|}
 +
 
 +
The length given by the Packet Length field is the number of bytes that remain in that packet, including the Data Length field.
 +
 
 +
If Data Length is set to zero, then the packet is uncompressed; otherwise it is the size of the uncompressed packet.
 +
 
 +
If compressed, the uncompressed length of (Packet ID + Data) must be equal to or over the threshold set in the packet [[#Set Compression|Set Compression]], otherwise the receiving party will disconnect.
 +
 
 +
Compression can be disabled by sending the packet [[#Set Compression|Set Compression]] with a negative Threshold, or not sending the Set Compression packet at all.
 +
 
 +
== 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.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="4"| 0x00
 +
|rowspan="4"| Handshaking
 +
|rowspan="4"| Server
 +
| Protocol Version
 +
| VarInt
 +
| See [[protocol version numbers]] (currently 578 in Minecraft 1.15.2)
 +
|-
 +
| Server Address
 +
| String (255)
 +
| 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|status]], 2 for [[#Login|login]]
 +
|}
 +
 
 +
==== Legacy Server List Ping ====
 +
 
 +
{{Warning|This packet uses a nonstandard format. It is never length-prefixed, and the packet ID is an Unsigned Byte instead of a VarInt.}}
 +
 
 +
While not technically part of the current protocol, legacy clients may send this packet to initiate [[Server List Ping]], and modern servers should handle it correctly.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0xFE
 +
| Handshaking
 +
| Server
 +
| Payload
 +
| Unsigned Byte
 +
| always 1 (<code>0x01</code>)
 +
|}
 +
 
 +
See [[Server List Ping#1.6]] for the details of the protocol that follows this packet.
 +
 
 +
== Status ==
 +
{{Main|Server List Ping}}
 +
 
 +
=== Clientbound ===
 +
 
 +
==== Response ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x00
 +
|rowspan="2"| Status
 +
|rowspan="2"| Client
 +
|-
 +
| JSON Response
 +
| String (32767)
 +
| See [[Server List Ping#Response]]; as with all strings this is prefixed by its length as a VarInt
 +
|}
 +
 
 +
==== Pong ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="1"| 0x01
 +
|rowspan="1"| Status
 +
|rowspan="1"| Client
 +
| Payload
 +
| Long
 +
| Should be the same as sent by the client
 +
|}
 +
 
 +
=== Serverbound ===
 +
 
 +
==== Request ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="1"| 0x00
 +
| Status
 +
| Server
 +
|colspan="3"| ''no fields''
 +
|}
 +
 
 +
==== Ping ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="1"| 0x01
 +
|rowspan="1"| Status
 +
|rowspan="1"| Server
 +
| Payload
 +
| Long
 +
| May be any number. Notchian clients use a system-dependent time value which is counted in milliseconds.
 +
|}
 +
 
 +
== Login ==
 +
 
 +
The login process is as follows:
 +
 
 +
# C→S: [[#Handshake|Handshake]] with Next State set to 2 (login)
 +
# C→S: [[#Login Start|Login Start]]
 +
# S→C: [[#Encryption Request|Encryption Request]]
 +
# Client auth
 +
# C→S: [[#Encryption Response|Encryption Response]]
 +
# Server auth, both enable encryption
 +
# S→C: [[#Set Compression|Set Compression]] (optional)
 +
# S→C: [[#Login Success|Login Success]]
 +
 
 +
Set Compression, if present, must be sent before Login Success. Note that anything sent after Set Compression must use the [[#With_compression|Post Compression packet format]].
 +
 
 +
For unauthenticated ("cracked"/offline-mode) and localhost connections (either of the two conditions is enough for an unencrypted connection) there is no encryption. In that case [[#Login Start|Login Start]] is directly followed by [[#Login Success|Login Success]].
 +
 
 +
See [[Protocol Encryption]] for details.
 +
 
 +
=== Clientbound ===
 +
 
 +
==== Disconnect (login) ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="1"| 0x00
 +
|rowspan="1"| Login
 +
|rowspan="1"| Client
 +
| Reason
 +
| [[Chat]]
 +
|
 +
|}
 +
 
 +
==== Encryption Request ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="5"| 0x01
 +
|rowspan="5"| Login
 +
|rowspan="5"| Client
 +
| Server ID
 +
| String (20)
 +
| Appears to be empty
 +
|-
 +
| Public Key Length
 +
| VarInt
 +
| Length of Public Key
 +
|-
 +
| Public Key
 +
| Byte Array
 +
|
 +
|-
 +
| Verify Token Length
 +
| VarInt
 +
| Length of Verify Token. Always 4 for Notchian servers.
 +
|-
 +
| Verify Token
 +
| Byte Array
 +
| A sequence of random bytes generated by the server
 +
|}
 +
 
 +
See [[Protocol Encryption]] for details.
 +
 
 +
==== Login Success ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x02
 +
|rowspan="2"| Login
 +
|rowspan="2"| Client
 +
| UUID
 +
| String (36)
 +
| 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]].
 +
 
 +
{{Warning2|The (notchian) server might take a bit to fully transition to the Play state, so it's recommended to wait before sendings Play packets, either by setting a timeout, or waiting for Play packets from the server (usually [[#Player Info|Player Info]]).
 +
 
 +
The notchian client doesn't send any (non-[[#Keep Alive|keep alive]]) packets until the next tick/[[#Time Update|time update]] packet.
 +
}}
 +
 
 +
==== Set Compression ====
 +
 
 +
Enables compression.  If compression is enabled, all following packets are encoded in the [[#With compression|compressed packet format]].  Negative or zero values will disable compression, meaning the packet format should remain in the [[#Without compression|uncompressed packet format]].  However, this packet is entirely optional, and if not sent, compression will also not be enabled (the notchian server does not send the packet when compression is disabled).
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="1"| 0x03
 +
|rowspan="1"| Login
 +
|rowspan="1"| Client
 +
| Threshold
 +
| VarInt
 +
| Maximum size of a packet before it is compressed
 +
|}
 +
 
 +
==== Login Plugin Request ====
 +
 
 +
Used to implement a custom handshaking flow together with [[#Login_Plugin_Response | Login Plugin Response]].
 +
 
 +
Unlike plugin messages in "play" mode, these messages follow a lock-step request/response scheme, where the client is expected to respond to a request indicating whether it understood. The notchian client always responds that it hasn't understood, and sends an empty payload.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="3"| 0x04
 +
|rowspan="3"| Login
 +
|rowspan="3"| Client
 +
| Message ID
 +
| VarInt
 +
| Generated by the server - should be unique to the connection.
 +
|-
 +
| Channel
 +
| Identifier
 +
| Name of the [[plugin channel]] used to send the data
 +
|-
 +
| Data
 +
| Byte Array
 +
| Any data, depending on the channel. The length of this array must be inferred from the packet length.
 +
|}
 +
 
 +
=== Serverbound ===
 +
 
 +
==== Login Start  ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="1"| 0x00
 +
|rowspan="1"| Login
 +
|rowspan="1"| Server
 +
| Name
 +
| String (16)
 +
| Player's Username
 +
|}
 +
 
 +
==== Encryption Response ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="4"| 0x01
 +
|rowspan="4"| Login
 +
|rowspan="4"| Server
 +
| Shared Secret Length
 +
| VarInt
 +
| Length of Shared Secret
 +
|-
 +
| Shared Secret
 +
| Byte Array
 +
|
 +
|-
 +
| Verify Token Length
 +
| VarInt
 +
| Length of Verify Token
 +
|-
 +
| Verify Token
 +
| Byte Array
 +
|
 +
|}
 +
 
 +
See [[Protocol Encryption]] for details.
 +
 
 +
==== Login Plugin Response ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="3"| 0x02
 +
|rowspan="3"| Login
 +
|rowspan="3"| Server
 +
| Message ID
 +
| VarInt
 +
| Should match ID from server.
 +
|-
 +
| Successful
 +
| Boolean
 +
| <code>true</code> if the client understands the request, <code>false</code> otherwise. When <code>false</code>, no payload follows.
 +
|-
 +
| Data
 +
| Optional Byte Array
 +
| Any data, depending on the channel. The length of this array must be inferred from the packet length.
 +
|}
 +
 
 +
== Play ==
 +
 
 +
=== Clientbound ===
 +
 
 +
==== Spawn Entity ====
 +
 
 +
Sent by the server when a vehicle or other non-living entity is created.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="12"| 0x00
 +
|rowspan="12"| Play
 +
|rowspan="12"| Client
 +
| Entity ID
 +
| VarInt
 +
| EID of the entity
 +
|-
 +
| Object UUID
 +
| UUID
 +
|
 +
|-
 +
| Type
 +
| VarInt
 +
| The type of entity (same as in [[#Spawn Living Entity|Spawn Living Entity]])
 +
|-
 +
| X
 +
| Double
 +
|
 +
|-
 +
| Y
 +
| Double
 +
|
 +
|-
 +
| Z
 +
| Double
 +
|
 +
|-
 +
| Pitch
 +
| Angle
 +
|
 +
|-
 +
| Yaw
 +
| Angle
 +
|
 +
|-
 +
| Data
 +
| Int
 +
| Meaning dependent on the value of the Type field, see [[Object Data]] for details.
 +
|-
 +
| Velocity X
 +
| Short
 +
|rowspan="3"| Same units as [[#Entity Velocity|Entity Velocity]].  Always sent, but only used when Data is greater than 0 (except for some entities which always ignore it; see [[Object Data]] for details).
 +
|-
 +
| Velocity Y
 +
| Short
 +
|-
 +
| Velocity Z
 +
| Short
 +
|}
 +
 
 +
==== Spawn Experience Orb ====
 +
 
 +
Spawns one or more experience orbs.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="5"| 0x01
 +
|rowspan="5"| Play
 +
|rowspan="5"| Client
 +
| Entity ID
 +
| VarInt
 +
|
 +
|-
 +
| X
 +
| Double
 +
|
 +
|-
 +
| Y
 +
| Double
 +
|
 +
|-
 +
| Z
 +
| Double
 +
|
 +
|-
 +
| Count
 +
| Short
 +
| The amount of experience this orb will reward once collected
 +
|}
 +
 
 +
==== Spawn Weather Entity ====
 +
 
 +
With this packet, the server notifies the client of thunderbolts striking within a 512 block radius around the player. The coordinates specify where exactly the thunderbolt strikes.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="5"| 0x02
 +
|rowspan="5"| Play
 +
|rowspan="5"| Client
 +
| Entity ID
 +
| VarInt
 +
| The EID of the thunderbolt
 +
|-
 +
| Type
 +
| Byte Enum
 +
| The global entity type, currently always 1 for thunderbolt
 +
|-
 +
| X
 +
| Double
 +
|
 +
|-
 +
| Y
 +
| Double
 +
|
 +
|-
 +
| Z
 +
| Double
 +
|
 +
|}
 +
 
 +
==== Spawn Living Entity ====
 +
 
 +
Sent by the server when a living entity is spawned.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="12"| 0x03
 +
|rowspan="12"| Play
 +
|rowspan="12"| Client
 +
| Entity ID
 +
| VarInt
 +
|
 +
|-
 +
| Entity UUID
 +
| UUID
 +
|
 +
|-
 +
| Type
 +
| VarInt
 +
| The type of mob. See [[Entities#Mobs]]
 +
|-
 +
| X
 +
| Double
 +
|
 +
|-
 +
| Y
 +
| Double
 +
|
 +
|-
 +
| Z
 +
| Double
 +
|
 +
|-
 +
| Yaw
 +
| Angle
 +
|
 +
|-
 +
| Pitch
 +
| Angle
 +
|
 +
|-
 +
| Head Pitch
 +
| Angle
 +
|
 +
|-
 +
| Velocity X
 +
| Short
 +
| Same units as [[#Entity Velocity|Entity Velocity]]
 +
|-
 +
| Velocity Y
 +
| Short
 +
| Same units as [[#Entity Velocity|Entity Velocity]]
 +
|-
 +
| Velocity Z
 +
| Short
 +
| Same units as [[#Entity Velocity|Entity Velocity]]
 +
|}
 +
 
 +
==== Spawn Painting ====
 +
 
 +
This packet shows location, name, and type of painting.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="5"| 0x04
 +
|rowspan="5"| Play
 +
|rowspan="5"| Client
 +
| Entity ID
 +
| VarInt
 +
|
 +
|-
 +
| Entity UUID
 +
| UUID
 +
|
 +
|-
 +
| Motive
 +
| VarInt
 +
| 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 <code>(0, 0)</code> being the top left corner, the center is <code>(max(0, width / 2 - 1), height / 2)</code>. E.g. <code>(1, 0)</code> for a 2×1 painting, or <code>(1, 2)</code> for a 4×4 painting.
 +
 
 +
List of paintings by coordinates in <code>paintings_kristoffer_zetterstrand.png</code> (where x and y are in pixels from the top left and width and height are in pixels or 16ths of a block):
 +
 
 +
{| class="wikitable"
 +
! Name
 +
! ID
 +
! x
 +
! y
 +
! width
 +
! height
 +
|-
 +
| <code>minecraft:kebab</code>
 +
| 0
 +
| 0
 +
| 0
 +
| 16
 +
| 16
 +
|-
 +
| <code>minecraft:aztec</code>
 +
| 1
 +
| 16
 +
| 0
 +
| 16
 +
| 16
 +
|-
 +
| <code>minecraft:alban</code>
 +
| 2
 +
| 32
 +
| 0
 +
| 16
 +
| 16
 +
|-
 +
| <code>minecraft:aztec2</code>
 +
| 3
 +
| 48
 +
| 0
 +
| 16
 +
| 16
 +
|-
 +
| <code>minecraft:bomb</code>
 +
| 4
 +
| 64
 +
| 0
 +
| 16
 +
| 16
 +
|-
 +
| <code>minecraft:plant</code>
 +
| 5
 +
| 80
 +
| 0
 +
| 16
 +
| 16
 +
|-
 +
| <code>minecraft:wasteland</code>
 +
| 6
 +
| 96
 +
| 0
 +
| 16
 +
| 16
 +
|-
 +
| <code>minecraft:pool</code>
 +
| 7
 +
| 0
 +
| 32
 +
| 32
 +
| 16
 +
|-
 +
| <code>minecraft:courbet</code>
 +
| 8
 +
| 32
 +
| 32
 +
| 32
 +
| 16
 +
|-
 +
| <code>minecraft:sea</code>
 +
| 9
 +
| 64
 +
| 32
 +
| 32
 +
| 16
 +
|-
 +
| <code>minecraft:sunset</code>
 +
| 10
 +
| 96
 +
| 32
 +
| 32
 +
| 16
 +
|-
 +
| <code>minecraft:creebet</code>
 +
| 11
 +
| 128
 +
| 32
 +
| 32
 +
| 16
 +
|-
 +
| <code>minecraft:wanderer</code>
 +
| 12
 +
| 0
 +
| 64
 +
| 16
 +
| 32
 +
|-
 +
| <code>minecraft:graham</code>
 +
| 13
 +
| 16
 +
| 64
 +
| 16
 +
| 32
 +
|-
 +
| <code>minecraft:match</code>
 +
| 14
 +
| 0
 +
| 128
 +
| 32
 +
| 32
 +
|-
 +
| <code>minecraft:bust</code>
 +
| 15
 +
| 32
 +
| 128
 +
| 32
 +
| 32
 +
|-
 +
| <code>minecraft:stage</code>
 +
| 16
 +
| 64
 +
| 128
 +
| 32
 +
| 32
 +
|-
 +
| <code>minecraft:void</code>
 +
| 17
 +
| 96
 +
| 128
 +
| 32
 +
| 32
 +
|-
 +
| <code>skull_and_roses</code>
 +
| 18
 +
| 128
 +
| 128
 +
| 32
 +
| 32
 +
|-
 +
| <code>minecraft:wither</code>
 +
| 19
 +
| 160
 +
| 128
 +
| 32
 +
| 32
 +
|-
 +
| <code>minecraft:fighters</code>
 +
| 20
 +
| 0
 +
| 96
 +
| 64
 +
| 32
 +
|-
 +
| <code>minecraft:pointer</code>
 +
| 21
 +
| 0
 +
| 192
 +
| 64
 +
| 64
 +
|-
 +
| <code>minecraft:pigscene</code>
 +
| 22
 +
| 64
 +
| 192
 +
| 64
 +
| 64
 +
|-
 +
| <code>minecraft:burning_skull</code>
 +
| 23
 +
| 128
 +
| 192
 +
| 64
 +
| 64
 +
|-
 +
| <code>minecraft:skeleton</code>
 +
| 24
 +
| 192
 +
| 64
 +
| 64
 +
| 48
 +
|-
 +
| <code>minecraft:donkey_kong</code>
 +
| 25
 +
| 192
 +
| 112
 +
| 64
 +
| 48
 +
|}
 +
 
 +
The {{Minecraft Wiki|Painting#Canvases|Minecraft Wiki article on paintings}} also provides a list of painting names to the actual images.
 +
 
 +
==== Spawn Player ====
 +
 
 +
This packet is sent by the server when a player comes into visible range, ''not'' when a player joins.
 +
 
 +
This packet must be sent after the [[#Player Info|Player Info]] packet that adds the player data for the client to use when spawning a player. If the Player Info for the player spawned by this packet is not present when this packet arrives, Notchian clients will not spawn the player entity. The Player Info packet includes skin/cape data.
 +
 
 +
Servers can, however, safely spawn player entities for players not in visible range. The client appears to handle it correctly.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="7"| 0x05
 +
|rowspan="7"| Play
 +
|rowspan="7"| Client
 +
| Entity ID
 +
| VarInt
 +
| Player's EID
 +
|-
 +
| Player UUID
 +
| UUID
 +
| See below for notes on {{Minecraft Wiki|Server.properties#online-mode|offline mode}} and NPCs
 +
|-
 +
| X
 +
| Double
 +
|
 +
|-
 +
| Y
 +
| Double
 +
|
 +
|-
 +
| Z
 +
| Double
 +
|
 +
|-
 +
| Yaw
 +
| Angle
 +
|
 +
|-
 +
| Pitch
 +
| Angle
 +
|
 +
|}
 +
 
 +
When in {{Minecraft Wiki|Server.properties#online-mode|online mode}}, the UUIDs must be valid and have valid skin blobs.
 +
 
 +
In offline mode, [[Wikipedia:Universally unique identifier#Versions 3 and 5 (namespace name-based)|UUID v3]] is used with the String <code>OfflinePlayer:&lt;player name&gt;</code>, encoded in UTF-8 (and case-sensitive).
 +
 
 +
For NPCs UUID v2 should be used. Note:
 +
 
 +
<+Grum> i will never confirm this as a feature you know that :)
 +
 
 +
In an example UUID, <code>xxxxxxxx-xxxx-Yxxx-xxxx-xxxxxxxxxxxx</code>, the UUID version is specified by <code>Y</code>. So, for UUID v3, <code>Y</code> will always be <code>3</code>, and for UUID v2, <code>Y</code> will always be <code>2</code>.
 +
 
 +
==== Entity Animation (clientbound) ====
 +
 
 +
Sent whenever an entity should change animation.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x06
 +
|rowspan="2"| Play
 +
|rowspan="2"| Client
 +
| Entity ID
 +
| VarInt
 +
| Player ID
 +
|-
 +
| Animation
 +
| Unsigned Byte
 +
| Animation ID (see below)
 +
|}
 +
 
 +
Animation can be one of the following values:
 +
 
 +
{| class="wikitable"
 +
! ID
 +
! Animation
 +
|-
 +
| 0
 +
| Swing main arm
 +
|-
 +
| 1
 +
| Take damage
 +
|-
 +
| 2
 +
| Leave bed
 +
|-
 +
| 3
 +
| Swing offhand
 +
|-
 +
| 4
 +
| Critical effect
 +
|-
 +
| 5
 +
| Magic critical effect
 +
|}
 +
 
 +
==== Statistics ====
 +
 
 +
Sent as a response to [[#Client_Status|Client Status 0x04]] (id 1).
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
!colspan="2"| Field Name
 +
!colspan="2"| Field Type
 +
! Notes
 +
|-
 +
|rowspan="4"| 0x07
 +
|rowspan="4"| Play
 +
|rowspan="4"| Client
 +
|colspan="2"| Count
 +
|colspan="2"| VarInt
 +
| Number of elements in the following array
 +
|-
 +
|rowspan="2"| Statistic
 +
| Category ID
 +
|rowspan="2"| Array
 +
| VarInt
 +
| See below
 +
|-
 +
| Statistic ID
 +
| VarInt
 +
| See below
 +
|-
 +
|colspan="2"| Value
 +
|colspan="2"| VarInt
 +
| The amount to set it to
 +
|}
 +
 
 +
Categories (these are namespaced, but with <code>:</code> replaced with <code>.</code>):
 +
 
 +
{| class="wikitable"
 +
! Name
 +
! ID
 +
! Registry
 +
|-
 +
| <code>minecraft.mined</code>
 +
| 0
 +
| Blocks
 +
|-
 +
| <code>minecraft.crafted</code>
 +
| 1
 +
| Items
 +
|-
 +
| <code>minecraft.used</code>
 +
| 2
 +
| Items
 +
|-
 +
| <code>minecraft.broken</code>
 +
| 3
 +
| Items
 +
|-
 +
| <code>minecraft.picked_up</code>
 +
| 4
 +
| Items
 +
|-
 +
| <code>minecraft.dropped</code>
 +
| 5
 +
| Items
 +
|-
 +
| <code>minecraft.killed</code>
 +
| 6
 +
| Entities
 +
|-
 +
| <code>minecraft.killed_by</code>
 +
| 7
 +
| Entities
 +
|-
 +
| <code>minecraft.custom</code>
 +
| 8
 +
| Custom
 +
|}
 +
 
 +
Blocks, Items, and Entities use block (not block state), item, and entity ids.
 +
 
 +
Custom has the following (unit only matters for clients):
 +
 
 +
{| class="wikitable"
 +
! Name
 +
! ID
 +
! Unit
 +
|-
 +
| <code>minecraft.leave_game</code>
 +
| 0
 +
| None
 +
|-
 +
| <code>minecraft.play_one_minute</code>
 +
| 1
 +
| Time
 +
|-
 +
| <code>minecraft.time_since_death</code>
 +
| 2
 +
| Time
 +
|-
 +
| <code>minecraft.sneak_Time</code>
 +
| 3
 +
| Time
 +
|-
 +
| <code>minecraft.walk_one_cm</code>
 +
| 4
 +
| Distance
 +
|-
 +
| <code>minecraft.crouch_one_cm</code>
 +
| 5
 +
| Distance
 +
|-
 +
| <code>minecraft.sprint_one_cm</code>
 +
| 6
 +
| Distance
 +
|-
 +
| <code>minecraft.swim_one_cm</code>
 +
| 7
 +
| Distance
 +
|-
 +
| <code>minecraft.fall_one_cm</code>
 +
| 8
 +
| Distance
 +
|-
 +
| <code>minecraft.climb_one_cm</code>
 +
| 9
 +
| Distance
 +
|-
 +
| <code>minecraft.fly_one_cm</code>
 +
| 10
 +
| Distance
 +
|-
 +
| <code>minecraft.dive_one_cm</code>
 +
| 11
 +
| Distance
 +
|-
 +
| <code>minecraft.minecart_one_cm</code>
 +
| 12
 +
| Distance
 +
|-
 +
| <code>minecraft.boat_one_cm</code>
 +
| 13
 +
| Distance
 +
|-
 +
| <code>minecraft.pig_one_cm</code>
 +
| 14
 +
| Distance
 +
|-
 +
| <code>minecraft.horse_one_cm</code>
 +
| 15
 +
| Distance
 +
|-
 +
| <code>minecraft.aviate_one_cm</code>
 +
| 16
 +
| Distance
 +
|-
 +
| <code>minecraft.jump</code>
 +
| 17
 +
| None
 +
|-
 +
| <code>minecraft.drop</code>
 +
| 18
 +
| None
 +
|-
 +
| <code>minecraft.damage_dealt</code>
 +
| 19
 +
| Damage
 +
|-
 +
| <code>minecraft.damage_taken</code>
 +
| 20
 +
| Damage
 +
|-
 +
| <code>minecraft.deaths</code>
 +
| 21
 +
| None
 +
|-
 +
| <code>minecraft.mob_kills</code>
 +
| 22
 +
| None
 +
|-
 +
| <code>minecraft.animals_bred</code>
 +
| 23
 +
| None
 +
|-
 +
| <code>minecraft.player_kills</code>
 +
| 24
 +
| None
 +
|-
 +
| <code>minecraft.fish_caught</code>
 +
| 25
 +
| None
 +
|-
 +
| <code>minecraft.talked_to_villager</code>
 +
| 26
 +
| None
 +
|-
 +
| <code>minecraft.traded_with_villager</code>
 +
| 27
 +
| None
 +
|-
 +
| <code>minecraft.eat_cake_slice</code>
 +
| 28
 +
| None
 +
|-
 +
| <code>minecraft.fill_cauldron</code>
 +
| 29
 +
| None
 +
|-
 +
| <code>minecraft.use_cauldron</code>
 +
| 30
 +
| None
 +
|-
 +
| <code>minecraft.clean_armor</code>
 +
| 31
 +
| None
 +
|-
 +
| <code>minecraft.clean_banner</code>
 +
| 32
 +
| None
 +
|-
 +
| <code>minecraft.interact_with_brewingstand</code>
 +
| 33
 +
| None
 +
|-
 +
| <code>minecraft.interact_with_beacon</code>
 +
| 34
 +
| None
 +
|-
 +
| <code>minecraft.inspect_dropper</code>
 +
| 35
 +
| None
 +
|-
 +
| <code>minecraft.inspect_hopper</code>
 +
| 36
 +
| None
 +
|-
 +
| <code>minecraft.inspect_dispenser</code>
 +
| 37
 +
| None
 +
|-
 +
| <code>minecraft.play_noteblock</code>
 +
| 38
 +
| None
 +
|-
 +
| <code>minecraft.tune_noteblock</code>
 +
| 39
 +
| None
 +
|-
 +
| <code>minecraft.pot_flower</code>
 +
| 40
 +
| None
 +
|-
 +
| <code>minecraft.trigger_trapped_chest</code>
 +
| 41
 +
| None
 +
|-
 +
| <code>minecraft.open_enderchest</code>
 +
| 42
 +
| None
 +
|-
 +
| <code>minecraft.enchant_item</code>
 +
| 43
 +
| None
 +
|-
 +
| <code>minecraft.play_record</code>
 +
| 44
 +
| None
 +
|-
 +
| <code>minecraft.interact_with_furnace</code>
 +
| 45
 +
| None
 +
|-
 +
| <code>minecraft.interact_with_crafting_table</code>
 +
| 46
 +
| None
 +
|-
 +
| <code>minecraft.open_chest</code>
 +
| 47
 +
| None
 +
|-
 +
| <code>minecraft.sleep_in_bed</code>
 +
| 48
 +
| None
 +
|-
 +
| <code>minecraft.open_shulker_box</code>
 +
| 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
 +
 
 +
==== Acknowledge Player Digging ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="4"| 0x08
 +
|rowspan="4"| Play
 +
|rowspan="4"| Client
 +
| Location
 +
| Position
 +
| Position where the digging was happening
 +
|-
 +
| Block
 +
| VarInt
 +
| Block state ID of the block that should be at that position now.
 +
|-
 +
| Status
 +
| VarInt enum
 +
| Same as Player Digging.  Only Started digging (0), Cancelled digging (1), and Finished digging (2) are used.
 +
|-
 +
| Successful
 +
| Boolean
 +
| True if the digging succeeded; false if the client should undo any changes it made locally.  (How does this work?)
 +
|}
 +
 
 +
==== Block Break Animation ====
 +
 
 +
0–9 are the displayable destroy stages and each other number means that there is no animation on this coordinate.
 +
 
 +
Block break animations can still be applied on air; the animation will remain visible although there is no block being broken.  However, if this is applied to a transparent block, odd graphical effects may happen, including water losing its transparency.  (An effect similar to this can be seen in normal gameplay when breaking ice blocks)
 +
 
 +
If you need to display several break animations at the same time you have to give each of them a unique Entity ID. The entity ID does not need to correspond to an actual entity on the client. It is valid to use a randomly generated number.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="3"| 0x09
 +
|rowspan="3"| Play
 +
|rowspan="3"| Client
 +
| Entity ID
 +
| VarInt
 +
| Entity ID of the entity breaking the block
 +
|-
 +
| Location
 +
| Position
 +
| Block Position
 +
|-
 +
| Destroy Stage
 +
| Byte
 +
| 0–9 to set it, any other value to remove it
 +
|}
 +
 
 +
==== Block Entity Data ====
 +
 
 +
Sets the block entity associated with the block at the given location.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="3"| 0x0A
 +
|rowspan="3"| Play
 +
|rowspan="3"| Client
 +
| Location
 +
| Position
 +
|
 +
|-
 +
| Action
 +
| Unsigned Byte
 +
| The type of update to perform, see below
 +
|-
 +
| NBT Data
 +
| [[NBT|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''': 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''': Unused
 +
* '''11''': Declare a bed
 +
* '''12''': Set data of a jigsaw block
 +
* '''13''': Set items in a campfire
 +
* '''14''': Behive information
 +
 
 +
==== Block Action ====
 +
 
 +
This packet is used for a number of actions and animations performed by blocks, usually non-persistent.
 +
 
 +
See [[Block Actions]] for a list of values.
 +
 
 +
{{Warning2|This packet uses a block ID, not a block state.  Unfortunately, block IDs are not directly included in the output from [[Data Generators]], but can manually be calculated.}}
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="4"| 0x0B
 +
|rowspan="4"| Play
 +
|rowspan="4"| Client
 +
| Location
 +
| Position
 +
| Block coordinates
 +
|-
 +
| Action ID (Byte 1)
 +
| Unsigned Byte
 +
| Varies depending on block — see [[Block Actions]]
 +
|-
 +
| Action Param (Byte 2)
 +
| Unsigned Byte
 +
| Varies depending on block — see [[Block Actions]]
 +
|-
 +
| Block Type
 +
| VarInt
 +
| The block type ID for the block.  This must match the block at the given coordinates.
 +
|}
 +
 
 +
==== 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"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x0C
 +
|rowspan="2"| Play
 +
|rowspan="2"| Client
 +
| Location
 +
| Position
 +
| Block Coordinates
 +
|-
 +
| Block ID
 +
| VarInt
 +
| The new block state ID for the block as given in the {{Minecraft Wiki|Data values#Block IDs|global palette}}. See that section for more information.
 +
|}
 +
 
 +
==== Boss Bar ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
!colspan="2"| Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="14"| 0x0D
 +
|rowspan="14"| Play
 +
|rowspan="14"| Client
 +
|colspan="2"| UUID
 +
| UUID
 +
| Unique ID for this bar
 +
|-
 +
|colspan="2"| Action
 +
| VarInt Enum
 +
| Determines the layout of the remaining packet
 +
|-
 +
! Action
 +
! Field Name
 +
!
 +
!
 +
|-
 +
|rowspan="5"| 0: add
 +
| Title
 +
| [[Chat]]
 +
|
 +
|-
 +
| Health
 +
| Float
 +
| From 0 to 1. Values greater than 1 do not crash a Notchian client, and start [https://i.johni0702.de/nA.png rendering part of a second health bar] at around 1.5.
 +
|-
 +
| Color
 +
| VarInt Enum
 +
| Color ID (see below)
 +
|-
 +
| Division
 +
| VarInt Enum
 +
| Type of division (see below)
 +
|-
 +
| Flags
 +
| Unsigned Byte
 +
| Bit mask. 0x1: should darken sky, 0x2: is dragon bar (used to play end music), 0x04: create fog (previously was also controlled by 0x02)
 +
|-
 +
| 1: remove
 +
| ''no fields''
 +
| ''no fields''
 +
| Removes this boss bar
 +
|-
 +
| 2: update health
 +
| Health
 +
| Float
 +
| as above
 +
|-
 +
| 3: update title
 +
| Title
 +
| [[Chat]]
 +
|
 +
|-
 +
|rowspan="2"| 4: update style
 +
| Color
 +
| VarInt Enum
 +
| Color ID (see below)
 +
|-
 +
| Dividers
 +
| VarInt Enum
 +
| as above
 +
|-
 +
| 5: update flags
 +
| Flags
 +
| Unsigned Byte
 +
| as above
 +
|-
 +
|}
 +
 
 +
{| class="wikitable"
 +
! ID
 +
! Color
 +
|-
 +
| 0
 +
| Pink
 +
|-
 +
| 1
 +
| Blue
 +
|-
 +
| 2
 +
| Red
 +
|-
 +
| 3
 +
| Green
 +
|-
 +
| 4
 +
| Yellow
 +
|-
 +
| 5
 +
| Purple
 +
|-
 +
| 6
 +
| White
 +
|}
 +
 
 +
{| class="wikitable"
 +
! ID
 +
! Type of division
 +
|-
 +
| 0
 +
| No division
 +
|-
 +
| 1
 +
| 6 notches
 +
|-
 +
| 2
 +
| 10 notches
 +
|-
 +
| 3
 +
| 12 notches
 +
|-
 +
| 4
 +
| 20 notches
 +
|}
 +
 
 +
==== Server Difficulty ====
 +
 
 +
Changes the difficulty setting in the client's option menu
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x0E
 +
|rowspan="2"| Play
 +
|rowspan="2"| Client
 +
| Difficulty
 +
| Unsigned Byte
 +
| 0: peaceful, 1: easy, 2: normal, 3: hard
 +
|-
 +
| Difficulty locked?
 +
| Boolean
 +
|
 +
|}
 +
 
 +
==== Chat Message (clientbound) ====
 +
 
 +
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.
 +
 
 +
{{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"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x0F
 +
|rowspan="2"| Play
 +
|rowspan="2"| Client
 +
| JSON Data
 +
| [[Chat]]
 +
| Limited to 32767 bytes
 +
|-
 +
| Position
 +
| Byte
 +
| 0: chat (chat box), 1: system message (chat box), 2: game info (above hotbar).
 +
|}
 +
 
 +
==== Multi Block Change ====
 +
 
 +
Fired whenever 2 or more blocks are changed within the same chunk on the same tick.
 +
 
 +
{{Warning|Changing blocks in chunks not loaded by the client is unsafe (see note on [[#Block Change|Block Change]]).}}
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
!colspan="2"| Field Name
 +
!colspan="2"| Field Type
 +
! Notes
 +
|-
 +
|rowspan="6"| 0x10
 +
|rowspan="6"| Play
 +
|rowspan="6"| Client
 +
|colspan="2"| Chunk X
 +
|colspan="2"| Int
 +
| Chunk X coordinate
 +
|-
 +
|colspan="2"| Chunk Z
 +
|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
 +
| The new block state ID for the block as given in the {{Minecraft Wiki|Data values#Block IDs|global palette}}. See that section for more information.
 +
|}
 +
 
 +
To decode the position into a world position:
 +
 
 +
<syntaxhighlight lang="java">
 +
worldX = (horizPos >> 4 & 15) + (chunkX * 16);
 +
worldY = vertPos;
 +
worldZ = (horizPos & 15) + (chunkZ * 16);
 +
</syntaxhighlight>
 +
 
 +
==== Tab-Complete (clientbound) ====
 +
 
 +
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.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
!colspan="2"| Field Name
 +
!colspan="2"| Field Type
 +
! Notes
 +
|-
 +
|rowspan="8"| 0x11
 +
|rowspan="8"| Play
 +
|rowspan="8"| Client
 +
|-
 +
|colspan="2"| ID
 +
|colspan="2"| VarInt
 +
| Transaction ID
 +
|-
 +
|colspan="2"| Start
 +
|colspan="2"| VarInt
 +
| Start of the text to replace
 +
|-
 +
|colspan="2"| Length
 +
|colspan="2"| VarInt
 +
| Length of the text to replace
 +
|-
 +
|colspan="2"| Count
 +
|colspan="2"| VarInt
 +
| Number of elements in the following array
 +
|-
 +
|rowspan="3"| Matches
 +
| Match
 +
|rowspan="3"| Array
 +
| String (32767)
 +
| One eligible 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 <code>/</code> 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 directed graph, with one root node.  Each redirect or child node must refer only to nodes that have already been declared.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="3"| 0x12
 +
|rowspan="3"| Play
 +
|rowspan="3"| Client
 +
| Count
 +
| VarInt
 +
| Number of elements in the following array
 +
|-
 +
| Nodes
 +
| Array of [[Command Data|Node]]
 +
| An array of nodes
 +
|-
 +
| Root index
 +
| VarInt
 +
| Index of the <code>root</code> node in the previous array
 +
|}
 +
 
 +
For more information on this packet, see the [[Command Data]] article.
 +
 
 +
==== Window Confirmation (clientbound) ====
 +
 
 +
A packet from the server indicating whether a request from the client was accepted, or whether there was a conflict (due to lag).  If the packet was not accepted, the client must respond with a [[#Window Confirmation (serverbound)|serverbound window confirmation]] packet.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="3"| 0x13
 +
|rowspan="3"| Play
 +
|rowspan="3"| Client
 +
| Window ID
 +
| Byte
 +
| The ID of the window that the action occurred in
 +
|-
 +
| Action Number
 +
| Short
 +
| Every action that is to be accepted has a unique number. This number is an incrementing integer (starting at 0) with separate counts for each window ID.
 +
|-
 +
| Accepted
 +
| Boolean
 +
| Whether the action was accepted
 +
|}
 +
 
 +
==== Close Window (clientbound) ====
 +
 
 +
This packet is sent from the server to the client when a window is forcibly closed, such as when a chest is destroyed while it's open.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x14
 +
| Play
 +
| Client
 +
| Window ID
 +
| Unsigned Byte
 +
| This is the ID of the window that was closed. 0 for inventory.
 +
|}
 +
 
 +
==== Window Items ====
 +
[[File:Inventory-slots.png|thumb|The inventory slots]]
 +
 
 +
Sent by the server when items in multiple slots (in a window) are added/removed. This includes the main inventory, equipped armour and crafting slots.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="3"| 0x15
 +
|rowspan="3"| Play
 +
|rowspan="3"| Client
 +
| Window ID
 +
| Unsigned Byte
 +
| The ID of window which items are being sent for. 0 for player inventory.
 +
|-
 +
| Count
 +
| Short
 +
| Number of elements in the following array
 +
|-
 +
| Slot Data
 +
| Array of [[Slot Data|Slot]]
 +
|
 +
|}
 +
 
 +
See [[Inventory#Windows|inventory windows]] for further information about how slots are indexed.
 +
 
 +
==== Window Property ====
 +
 
 +
This packet is used to inform the client that part of a GUI window should be updated.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="3"| 0x16
 +
|rowspan="3"| Play
 +
|rowspan="3"| Client
 +
| Window ID
 +
| Unsigned Byte
 +
|
 +
|-
 +
| Property
 +
| Short
 +
| The property to be updated, see below
 +
|-
 +
| Value
 +
| Short
 +
| The new value for the property, see below
 +
|}
 +
 
 +
The meaning of the Property field depends on the type of the window. The following table shows the known combinations of window type and property, and how the value is to be interpreted.
 +
 
 +
{| class="wikitable"
 +
|-
 +
! Window type
 +
! Property
 +
! Value
 +
|-
 +
|rowspan="4"| Furnace
 +
| 0: Fire icon (fuel left)
 +
| counting from fuel burn time down to 0 (in-game ticks)
 +
|-
 +
| 1: Maximum fuel burn time
 +
| fuel burn time or 0 (in-game ticks)
 +
|-
 +
| 2: Progress arrow
 +
| counting from 0 to maximum progress (in-game ticks)
 +
|-
 +
| 3: Maximum progress
 +
| always 200 on the notchian server
 +
|-
 +
|rowspan="10"| Enchantment Table
 +
| 0: Level requirement for top enchantment slot
 +
|rowspan="3"| The enchantment's xp level requirement
 +
|-
 +
| 1: Level requirement for middle enchantment slot
 +
|-
 +
| 2: Level requirement for bottom enchantment slot
 +
|-
 +
| 3: The enchantment seed
 +
| Used for drawing the enchantment names (in [[Wikipedia:Standard Galactic Alphabet|SGA]]) clientside.  The same seed ''is'' used to calculate enchantments, but some of the data isn't sent to the client to prevent easily guessing the entire list (the seed value here is the regular seed bitwise and <code>0xFFFFFFF0</code>).
 +
|-
 +
| 4: Enchantment ID shown on mouse hover over top enchantment slot
 +
|rowspan="3"| The enchantment id (set to -1 to hide it), see below for values
 +
|-
 +
| 5: Enchantment ID shown on mouse hover over middle enchantment slot
 +
|-
 +
| 6: Enchantment ID shown on mouse hover over bottom enchantment slot
 +
|-
 +
| 7: Enchantment level shown on mouse hover over the top slot
 +
|rowspan="3"| The enchantment level (1 = I, 2 = II, 6 = VI, etc.), or -1 if no enchant
 +
|-
 +
| 8: Enchantment level shown on mouse hover over the middle slot
 +
|-
 +
| 9: Enchantment level shown on mouse hover over the bottom slot
 +
|-
 +
|rowspan="3"| Beacon
 +
| 0: Power level
 +
| 0-4, controls what effect buttons are enabled
 +
|-
 +
| 1: First potion effect
 +
| {{Minecraft Wiki|Data values#Status effects|Potion effect ID}} for the first effect, or -1 if no effect
 +
|-
 +
| 2: Second potion effect
 +
| {{Minecraft Wiki|Data values#Status effects|Potion effect ID}} for the second effect, or -1 if no effect
 +
|-
 +
| Anvil
 +
| 0: Repair cost
 +
| The repair's cost in xp levels
 +
|-
 +
|rowspan="2"| Brewing Stand
 +
| 0: Brew time
 +
| 0 – 400, with 400 making the arrow empty, and 0 making the arrow full
 +
|-
 +
| 1: Fuel time
 +
| 0 - 20, with 0 making the arrow empty, and 20 making the arrow full
 +
|}
 +
 
 +
For an enchanting table, the following numerical IDs are used:
 +
 
 +
{| class="wikitable"
 +
! Numerical ID
 +
! Enchantment ID
 +
! Enchantment Name
 +
|-
 +
| 0
 +
| minecraft:protection
 +
| Protection
 +
|-
 +
| 1
 +
| minecraft:fire_protection
 +
| Fire Protection
 +
|-
 +
| 2
 +
| minecraft:feather_falling
 +
| Feather Falling
 +
|-
 +
| 3
 +
| minecraft:blast_protection
 +
| Blast Protection
 +
|-
 +
| 4
 +
| minecraft:projectile_protection
 +
| Projectile Protection
 +
|-
 +
| 5
 +
| minecraft:respiration
 +
| Respiration
 +
|-
 +
| 6
 +
| minecraft:aqua_affinity
 +
| Aqua Affinity
 +
|-
 +
| 7
 +
| minecraft:thorns
 +
| Thorns
 +
|-
 +
| 8
 +
| minecraft:depth_strider
 +
| Depth Strider
 +
|-
 +
| 9
 +
| minecraft:frost_walker
 +
| Frost Walker
 +
|-
 +
| 10
 +
| minecraft:binding_curse
 +
| Curse of Binding
 +
|-
 +
| 11
 +
| minecraft:sharpness
 +
| Sharpness
 +
|-
 +
| 12
 +
| minecraft:smite
 +
| Smite
 +
|-
 +
| 13
 +
| minecraft:bane_of_arthropods
 +
| Bane of Arthropods
 +
|-
 +
| 14
 +
| minecraft:knockback
 +
| Knockback
 +
|-
 +
| 15
 +
| minecraft:fire_aspect
 +
| Fire Aspect
 +
|-
 +
| 16
 +
| minecraft:looting
 +
| Looting
 +
|-
 +
| 17
 +
| minecraft:sweeping
 +
| Sweeping Edge
 +
|-
 +
| 18
 +
| minecraft:efficiency
 +
| Efficiency
 +
|-
 +
| 19
 +
| minecraft:silk_touch
 +
| Silk Touch
 +
|-
 +
| 20
 +
| minecraft:unbreaking
 +
| Unbreaking
 +
|-
 +
| 21
 +
| minecraft:fortune
 +
| Fortune
 +
|-
 +
| 22
 +
| minecraft:power
 +
| Power
 +
|-
 +
| 23
 +
| minecraft:punch
 +
| Punch
 +
|-
 +
| 24
 +
| minecraft:flame
 +
| Flame
 +
|-
 +
| 25
 +
| minecraft:infinity
 +
| Infinity
 +
|-
 +
| 26
 +
| minecraft:luck_of_the_sea
 +
| Luck of the Sea
 +
|-
 +
| 27
 +
| minecraft:lure
 +
| Lure
 +
|-
 +
| 28
 +
| minecraft:loyalty
 +
| Loyalty
 +
|-
 +
| 29
 +
| minecraft:impaling
 +
| Impaling
 +
|-
 +
| 30
 +
| minecraft:riptide
 +
| Riptide
 +
|-
 +
| 31
 +
| minecraft:channeling
 +
| Channeling
 +
|-
 +
| 32
 +
| minecraft:mending
 +
| Mending
 +
|-
 +
| 33
 +
| minecraft:vanishing_curse
 +
| Curse of Vanishing
 +
|}
 +
 
 +
==== Set Slot ====
 +
 
 +
Sent by the server when an item in a slot (in a window) is added/removed.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="3"| 0x17
 +
|rowspan="3"| Play
 +
|rowspan="3"| Client
 +
| Window ID
 +
| Byte
 +
| The window which is being updated. 0 for player inventory. Note that all known window types include the player inventory. This packet will only be sent for the currently opened window while the player is performing actions, even if it affects the player inventory. After the window is closed, a number of these packets are sent to update the player's inventory window (0).
 +
|-
 +
| Slot
 +
| Short
 +
| The slot that should be updated
 +
|-
 +
| Slot Data
 +
| [[Slot Data|Slot]]
 +
|
 +
|}
 +
 
 +
To set the cursor (the item currently dragged with the mouse), use -1 as Window ID and as Slot.
 +
 
 +
This packet can only be used to edit the hotbar of the player's inventory if window ID is set to 0 (slots 36 through 44).  If the window ID is set to -2, then any slot in the inventory can be used but no add item animation will be played.
 +
 
 +
==== Set Cooldown ====
 +
 
 +
Applies a cooldown period to all items with the given type.  Used by the Notchian server with enderpearls.  This packet should be sent when the cooldown starts and also when the cooldown ends (to compensate for lag), although the client will end the cooldown automatically. Can be applied to any item, note that interactions still get sent to the server with the item but the client does not play the animation nor attempt to predict results (i.e block placing).
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x18
 +
|rowspan="2"| Play
 +
|rowspan="2"| Client
 +
| Item ID
 +
| VarInt
 +
| Numeric ID of the item to apply a cooldown to.
 +
|-
 +
| Cooldown Ticks
 +
| VarInt
 +
| Number of ticks to apply a cooldown for, or 0 to clear the cooldown.
 +
|}
 +
 
 +
==== Plugin Message (clientbound) ====
 +
 
 +
{{Main|Plugin channels}}
 +
 
 +
Mods and plugins can use this to send their data. Minecraft itself uses several [[plugin channel]]s. These internal channels are in the <code>minecraft</code> namespace.
 +
 
 +
More documentation on this: [http://dinnerbone.com/blog/2012/01/13/minecraft-plugin-channels-messaging/ http://dinnerbone.com/blog/2012/01/13/minecraft-plugin-channels-messaging/]
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x19
 +
|rowspan="2"| Play
 +
|rowspan="2"| Client
 +
| Channel
 +
| Identifier
 +
| Name of the [[plugin channel]] used to send the data
 +
|-
 +
| Data
 +
| Byte Array
 +
| Any data, depending on the channel. <code>minecraft:</code> channels are documented [[plugin channel|here]].  The length of this array must be inferred from the packet length.
 +
|}
 +
 
 +
==== Named Sound Effect ====
 +
{{See also|#Sound Effect}}
 +
 
 +
Used to play a sound effect on the client. Custom sounds may be added by resource packs.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="7"| 0x1A
 +
|rowspan="7"| Play
 +
|rowspan="7"| Client
 +
| Sound Name
 +
| Identifier
 +
| All sound effect names as of 1.15.2 can be seen [https://pokechu22.github.io/Burger/1.15.2.html#sounds here].
 +
|-
 +
| Sound Category
 +
| VarInt Enum
 +
| The category that this sound will be played from ([https://gist.github.com/konwboj/7c0c380d3923443e9d55 current categories])
 +
|-
 +
| Effect Position X
 +
| Int
 +
| Effect X multiplied by 8 ([[Data types#Fixed-point numbers|fixed-point number]] with only 3 bits dedicated to the fractional part)
 +
|-
 +
| 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
 +
|}
 +
 
 +
==== Disconnect (play) ====
 +
 
 +
Sent by the server before it disconnects a client. The client assumes that the server has already closed the connection by the time the packet arrives.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x1B
 +
| Play
 +
| Client
 +
| Reason
 +
| [[Chat]]
 +
| Displayed to the client when the connection terminates.
 +
|}
 +
 
 +
==== Entity Status ====
 +
 
 +
Entity statuses generally trigger an animation for an entity.  The available statuses vary by the entity's type (and are available to subclasses of that type as well).
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x1C
 +
|rowspan="2"| Play
 +
|rowspan="2"| Client
 +
| Entity ID
 +
| Int
 +
|
 +
|-
 +
| Entity Status
 +
| Byte Enum
 +
| See below
 +
|}
 +
 
 +
See [[Entity statuses]] for a list of which statuses are valid for each type of entity.
 +
 
 +
==== Explosion ====
 +
 
 +
Sent when an explosion occurs (creepers, TNT, and ghast fireballs).
 +
 
 +
Each block in Records is set to air. Coordinates for each axis in record is int(X) + record.x
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
| class="col0" |
+
! State
! class="col1" | Size
+
! Bound To
! class="col2" | Range
+
! Field Name
! class="col3" | Notes
+
! Field Type
|- class="row1"
+
! Notes
! class="col0 centeralign" | byte
+
|-
| class="col1 centeralign" | 1
+
|rowspan="9"| 0x1D
| class="col2" | -128 to 127
+
|rowspan="9"| Play
| class="col3" | Signed, two's complement
+
|rowspan="9"| Client
|- class="row2"
+
| X
! class="col0 centeralign" | short
+
| Float
| class="col1 centeralign" | 2
+
|  
| class="col2" | -32768 to 32767
+
|-
| class="col3" | Signed, two's complement
+
| Y
|- class="row3"
+
| Float
! class="col0 centeralign" | int
+
|  
| class="col1 centeralign" | 4
+
|-
| class="col2" | -2147483648 to 2147483647
+
| Z
| class="col3" | Signed, two's complement
+
| Float
|- class="row4"
+
|  
! class="col0 centeralign" | long
+
|-
| class="col1 centeralign" | 8
+
| Strength
| class="col2" | -9223372036854775808 to 9223372036854775807
+
| Float
| class="col3" | Signed, two's complement
+
| A strength greater than or equal to 2.0 spawns a <code>minecraft:explosion_emitter</code> particle, while a lesser strength spawns a <code>minecraft:explosion</code> particle.
|- class="row5"
+
|-
! class="col0 centeralign" | float
+
| Record Count
| class="col1 centeralign" | 4
+
| Int
| class="col2" |
+
| Number of elements in the following array
See [http://java.sun.com/docs/books/jls/third_edition/html/typesValues.html#4.2.3 this]
+
|-
| class="col3" | Single-precision 32-bit IEEE 754 floating point
+
| Records
|- class="row6"
+
| Array of (Byte, Byte, Byte)
! class="col0 centeralign" | double
+
| Each record is 3 signed bytes long; the 3 bytes are the XYZ (respectively) signed offsets of affected blocks.
| class="col1 centeralign" | 8
+
|-
| class="col2" |
+
| Player Motion X
See [http://java.sun.com/docs/books/jls/third_edition/html/typesValues.html#4.2.3 this]
+
| Float
| class="col3" | Double-precision 64-bit IEEE 754 floating point
+
| X velocity of the player being pushed by the explosion
|- class="row7"
+
|-
! class="col0 centeralign" | string
+
| Player Motion Y
| class="col1 centeralign" | ≥ 2
+
| Float
| class="col2" | N/A
+
| Y velocity of the player being pushed by the explosion
| class="col3" | [http://en.wikipedia.org/wiki/UTF-8#Modified_UTF-8 Modified UTF-8] string. Prefixed by a short containing the length of the string.
+
|-
|- class="row8"
+
| Player Motion Z
! class="col0 centeralign" | bool
+
| Float
| class="col1 centeralign" | 1
+
| Z velocity of the player being pushed by the explosion
| class="col2" | 0 or 1
+
|}
| class="col3" | Value can be either True (0x01) or False (0x00)
+
 
|- class="row9"
+
==== Unload Chunk ====
! class="col0 centeralign" | Metadata
 
| class="col1 centeralign" | varies
 
| class="col2" | See below
 
| class="Col3" | See below
 
|}
 
  
=== Metadata ===
+
Tells the client to unload a chunk column.
  
The Metadata type provides extra information about an entity, such as sheep color. Metadata was introduced in Beta 1.2. Currently, it takes the following form:
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x1E
 +
|rowspan="2"| Play
 +
|rowspan="2"| Client
 +
| Chunk X
 +
| Int
 +
| Block coordinate divided by 16, rounded down
 +
  |-
 +
| Chunk Z
 +
| Int
 +
  | Block coordinate divided by 16, rounded down
 +
|}
  
  let x = 0 of type byte
+
It is legal to send this packet even if the given chunk is not currently loaded.
  while (x = read byte from stream) does not equal 127:
 
      select based on value of (x >> 5):
 
          case 0: read byte from stream
 
          case 1: read short from stream
 
          case 2: read int from stream
 
          case 3: read float from stream
 
          case 4: read string from stream
 
          case 5: read short, byte, short from stream
 
      end select
 
  end while
 
The last 5 bits of x (x & 0x1F) are either an index or bitmask.  Currently, only "byte" type metadata has been seen from the server.
 
  
== Terminology ==
+
==== Change Game State ====
  
This is a fairly lengthy page, and to make it more readable certain terminology must be understood. Terms used on this page and their definition are provided below.
+
Used for a wide variety of game state things, from whether to bed use to gamemode to demo messages.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
| class="col0" |
+
! State
! class="col1" | Definition
+
! Bound To
|- class="row1"
+
! Field Name
! class="col0 centeralign" | Player
+
! Field Type
| class="col1" | When used in in the singular, Player always refers to the client connected to the server
+
! Notes
|- class="row2"
+
|-
! class="col0 centeralign" | Entity
+
|rowspan="2"| 0x1F
| class="col1" | Entity refers to any item, player or mob in the world. This definition is subject to change as Notch extends the protocol
+
|rowspan="2"| Play
|- class="row3"
+
|rowspan="2"| Client
! class="col0 centeralign" | EID
+
| Reason
| class="col1" | An EID - or Entity ID - is a unique 4-byte integer used to identify a specific entity
+
| Unsigned Byte
|- class="row4"
+
| See below
! class="col0 centeralign" | XYZ
+
|-
| class="col1" | In this document, the axis names are the same as those used by Notch. Y points upwards, X points South, and Z points West.
+
| Value
|- class="row5"
+
| Float
! class="col0 centeralign" | MOTD
+
| Depends on Reason
| class="col1" | Message Of The Day
+
|}
|}
 
  
== Units of Measurement ==
+
''Reason codes'':
  
There are several different units of measurement used in the protocol depending on what is being described. For example, it wouldn't make much sense to send the position of a block (which is a constant multiple of 32) in a floating point double.
+
{| class="wikitable"
 +
! Reason
 +
! Effect
 +
! Value
 +
|-
 +
| 0
 +
| Invalid Bed
 +
| Would be used to switch between messages, but the only used message is 0 for invalid bed
 +
|-
 +
| 1
 +
| End raining
 +
|
 +
|-
 +
| 2
 +
| Begin raining
 +
|
 +
|-
 +
| 3
 +
| Change gamemode
 +
| 0: Survival, 1: Creative, 2: Adventure, 3: Spectator
 +
|-
 +
| 4
 +
| Exit end
 +
| 0: Immediately send Client Status of respawn without showing end credits; 1: Show end credits and respawn at the when they finish showing (or when esc is pressed). 1 is sent if the player has not yet received the "The end?" advancement, while if they do have it 0 is used.
 +
|-
 +
| 5
 +
| Demo message
 +
| 0: Show welcome to demo screen, 101: Tell movement controls, 102: Tell jump control, 103: Tell inventory control, 104: Tell that the demo is over and print a message about how to take a screenshot
 +
|-
 +
| 6
 +
| Arrow hitting player
 +
| Appears to be played when an arrow strikes another player in Multiplayer
 +
|-
 +
| 7
 +
| Fade value
 +
| The current darkness value. 1 = Dark, 0 = Bright, Setting the value higher causes the game to change color and freeze
 +
|-
 +
| 8
 +
| Fade time
 +
| Time in ticks for the sky to fade
 +
|-
 +
| 9
 +
| Play pufferfish sting sound
 +
|-
 +
| 10
 +
| Play elder guardian mob appearance (effect and sound)
 +
|
 +
|-
 +
| 11
 +
| Enable respawn screen
 +
|  0: Enable respawn screen, 1: Immediately respawn (sent when the doImmediateRespawn gamerule changes)
 +
|}
  
A block represents 1 meter x 1 meter x 1 meter. There are 32 pixels per meter, and chunks are 16m x 128m x 16m.
+
==== Open Horse Window ====
 +
 
 +
This packet is used exclusively for opening the horse GUI. [[#Open Window|Open Window]] is used for all other GUIs.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
| class="col0" |
+
! State
! class="col1 centeralign" | Data Types
+
! Bound To
! class="col2 centeralign" | Units
+
! Field Name
! class="col3" | Represents
+
! Field Type
|- class="row1"
+
! Notes
! class="col0" | Absolute
+
|-
| class="col1 centeralign" | double
+
|rowspan="3"| 0x20
| class="col2 centeralign" | meters
+
|rowspan="3"| Play
| class="col3" | Represents an object's location in the world.
+
|rowspan="3"| Client
|- class="row2"
+
| Window ID?
! class="col0" | Absolute Integer
+
| Byte
| class="col1 centeralign" | int
+
|
| class="col2 centeralign" | pixels
+
|-
| class="col3" | Represents an object's location in the world. <br/> Functions the same as Absolute Double, but requires fewer bytes and is less precise. <br/> In C/C++/Java: <code>absolute_int = (int)(absolute_double * 32.0);</code>
+
| Number of slots?
|- class="row3"
+
| VarInt
! class="col0" | Block
+
|
| class="col1 centeralign" | byte, short, int
+
|-
| class="col2 centeralign" | meters
+
| Entity ID?
| class="col3" | Represents a block's location in the world.
+
| Integer
|- class="row4"
+
|
! class="col0" | Chunk
+
|}
| class="col1 centeralign" | short, int
+
 
| class="col2 centeralign" | chunks
+
==== Keep Alive (clientbound) ====
| class="col3" | Represents the position of a chunk.
+
 
|}
+
The server will frequently send out a keep-alive, each containing a random ID. The client must respond with the same packet. If the client does not respond to them for over 30 seconds, the server kicks the client. Vice versa, if the server does not send any keep-alives for 20 seconds, the client will disconnect and yields a "Timed out" exception.
 +
 
 +
The Notchian server uses a system-dependent time in milliseconds to generate the keep alive ID value.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="1"| 0x21
 +
|rowspan="1"| Play
 +
|rowspan="1"| Client
 +
| Keep Alive ID
 +
| Long
 +
|
 +
|}
 +
 
 +
==== Chunk Data ====
 +
{{Main|Chunk Format}}
 +
{{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).
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="10"| 0x22
 +
|rowspan="10"| Play
 +
|rowspan="10"| 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#Full chunk|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 <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
 +
| VarInt
 +
| Size of Data in bytes
 +
|-
 +
| Data
 +
| Byte array
 +
| See [[Chunk Format#Data structure|data structure]] in Chunk Format
 +
|-
 +
| Number of block entities
 +
| VarInt
 +
| Number of elements in the following array
 +
|-
 +
| Block entities
 +
| Array of [[NBT|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|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.
 +
 
 +
==== Effect ====
 +
Sent when a client is to play a sound or particle effect.
 +
 
 +
By default, the Minecraft client adjusts the volume of sound effects based on distance. The final boolean field is used to disable this, and instead the effect is played from 2 blocks away in the correct direction. Currently this is only used for effect 1023 (wither spawn), effect 1028 (enderdragon death), and effect 1038 (end portal opening); it is ignored on other effects.
  
== Packets ==
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="4"| 0x23
 +
|rowspan="4"| Play
 +
|rowspan="4"| Client
 +
| Effect ID
 +
| Int
 +
| The ID of the effect, see below
 +
|-
 +
| Location
 +
| Position
 +
| The location of the effect
 +
|-
 +
| Data
 +
| Int
 +
| Extra data for certain effects, see below
 +
|-
 +
| Disable Relative Volume
 +
| Boolean
 +
| See above
 +
|}
  
All packets begin with a single "Packet ID" byte.  Listed packet size includes this byte.  Packets are either "server to client", "client to server", or both.  If not specified, assume that the packet can be sent both ways.  There is no "length" field; for variable length packets, you must parse to the end to determine the length.
+
Effect IDs:
  
=== Keep Alive (0x00) ===
+
{| class="wikitable"
 +
! ID
 +
! Name
 +
! Data
 +
|-
 +
!colspan="3"| Sound
 +
|-
 +
| 1000
 +
| Dispenser dispenses
 +
|
 +
|-
 +
| 1001
 +
| Dispenser fails to dispense
 +
|
 +
|-
 +
| 1002
 +
| Dispenser shoots
 +
|
 +
|-
 +
| 1003
 +
| Ender eye launched
 +
|
 +
|-
 +
| 1004
 +
| Firework shot
 +
|
 +
|-
 +
| 1005
 +
| Iron door opened
 +
|
 +
|-
 +
| 1006
 +
| Wooden door opened
 +
|
 +
|-
 +
| 1007
 +
| Wooden trapdoor opened
 +
|
 +
|-
 +
| 1008
 +
| Fence gate opened
 +
|
 +
|-
 +
| 1009
 +
| Fire extinguished
 +
|
 +
|-
 +
| 1010
 +
| Play record
 +
| Special case, see below for more info
 +
|-
 +
| 1011
 +
| Iron door closed
 +
|
 +
|-
 +
| 1012
 +
| Wooden door closed
 +
|
 +
|-
 +
| 1013
 +
| Wooden trapdoor closed
 +
|
 +
|-
 +
| 1014
 +
| Fence gate closed
 +
|
 +
|-
 +
| 1015
 +
| Ghast warns
 +
|
 +
|-
 +
| 1016
 +
| Ghast shoots
 +
|
 +
|-
 +
| 1017
 +
| Enderdragon shoots
 +
|
 +
|-
 +
| 1018
 +
| Blaze shoots
 +
|
 +
|-
 +
| 1019
 +
| Zombie attacks wood door
 +
|
 +
|-
 +
| 1020
 +
| Zombie attacks iron door
 +
|
 +
|-
 +
| 1021
 +
| Zombie breaks wood door
 +
|
 +
|-
 +
| 1022
 +
| Wither breaks block
 +
|
 +
|-
 +
| 1023
 +
| Wither spawned
 +
|
 +
|-
 +
| 1024
 +
| Wither shoots
 +
|
 +
|-
 +
| 1025
 +
| Bat takes off
 +
|
 +
|-
 +
| 1026
 +
| Zombie infects
 +
|
 +
|-
 +
| 1027
 +
| Zombie villager converted
 +
|
 +
|-
 +
| 1028
 +
| Ender dragon death
 +
|
 +
|-
 +
| 1029
 +
| Anvil destroyed
 +
|
 +
|-
 +
| 1030
 +
| Anvil used
 +
|
 +
|-
 +
| 1031
 +
| Anvil landed
 +
|
 +
|-
 +
| 1032
 +
| Portal travel
 +
|
 +
|-
 +
| 1033
 +
| Chorus flower grown
 +
|
 +
|-
 +
| 1034
 +
| Chorus flower died
 +
|
 +
|-
 +
| 1035
 +
| Brewing stand brewed
 +
|
 +
|-
 +
| 1036
 +
| Iron trapdoor opened
 +
|
 +
|-
 +
| 1037
 +
| Iron trapdoor closed
 +
|
 +
|-
 +
| 1038
 +
| End portal created in overworld
 +
|
 +
|-
 +
| 1039
 +
| Phantom bites
 +
|
 +
|-
 +
| 1040
 +
| Zombie converts to drowned
 +
|
 +
|-
 +
| 1041
 +
| Husk converts to zombie by drowning
 +
|
 +
|-
 +
| 1042
 +
| Grindstone used
 +
|
 +
|-
 +
| 1043
 +
| Book page turned
 +
|
 +
|-
 +
|-
 +
!colspan="3"| Particle
 +
|-
 +
| 1500
 +
| Composter composts
 +
|
 +
|-
 +
| 1501
 +
| Lava converts block (either water to stone, or removes existing blocks such as torches)
 +
|
 +
|-
 +
| 1502
 +
| Redstone torch burns out
 +
|
 +
|-
 +
| 1503
 +
| Ender eye placed
 +
|
 +
|-
 +
| 2000
 +
| Spawns 10 smoke particles, e.g. from a fire
 +
| Direction, see below
 +
|-
 +
| 2001
 +
| Block break + block break sound
 +
| Block state, as an index into the global palette
 +
|-
 +
| 2002
 +
| Splash potion. Particle effect + glass break sound.
 +
| [http://minecraft.gamepedia.com/Data_values#Potions Potion ID]
 +
|-
 +
| 2003
 +
| Eye of Ender entity break animation — particles and sound
 +
|
 +
|-
 +
| 2004
 +
| Mob spawn particle effect: smoke + flames
 +
|
 +
|-
 +
| 2005
 +
| Bonemeal particles
 +
| How many particles to spawn (if set to 0, 15 are spawned)
 +
|-
 +
| 2006
 +
| Dragon breath
 +
|
 +
|-
 +
| 2007
 +
| Instant splash potion
 +
| [http://minecraft.gamepedia.com/Data_values#Potions Potion ID]
 +
|-
 +
| 2008
 +
| Ender dragon destroys block
 +
|
 +
|-
 +
| 2009
 +
| Wet sponge vaporizes in nether
 +
|
 +
|-
 +
| 3000
 +
| End gateway spawn
 +
|
 +
|-
 +
| 3001
 +
| Enderdragon growl
 +
|
 +
|}
  
This packet may be sent to keep the connection alive, or may be a relic of UDP testing. No one is really sure. What we do know is that the Beta server will disconnect a client if it doesn't receive at least one packet before 1200 in-game ticks, and the Beta client will time out the connection under the same conditions.
+
Smoke directions:
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! ID
! class="col0" | Packet ID
+
! Direction
|- class="row1"
+
|-
| class="col0 centeralign" | 0x00
+
| 0
|}
+
| South-East
 +
|-
 +
| 1
 +
| South
 +
|-
 +
| 2
 +
| South-West
 +
|-
 +
| 3
 +
| East
 +
|-
 +
| 4
 +
| (Up or middle ?)
 +
|-
 +
| 5
 +
| West
 +
|-
 +
| 6
 +
| North-East
 +
|-
 +
| 7
 +
| North
 +
|-
 +
| 8
 +
| North-West
 +
|}
  
=== Login Request (0x01) ===
+
Play record: This is actually a special case within this packet. You can start/stop a record at a specific location. Use a valid {{Minecraft Wiki|Music Discs|Record ID}} to start a record (or overwrite a currently playing one), any other value will stop the record.  See [[Data Generators]] for information on item IDs.
  
==== Client to Server ====
+
==== Particle ====
  
Sent by the client after the handshake to finish logging in. If the version is outdated or any field is invalid, the server will disconnect the client with a [[#Disconnect.2FKick_.280xFF.29|kick]]. If the client is started in offline mode, the player's username will default to <code>Player</code>, making LAN play with more than one player impossible (without authenticating) as the server will prevent multiple users with the same name.
+
Displays the named particle
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="5" | 0x01
+
|rowspan="11"| 0x24
| class="col1 centeralign" | Protocol Version
+
|rowspan="11"| Play
| class="col2 centeralign" | int
+
|rowspan="11"| Client
| class="col3 centeralign" | <code>8</code>
+
| Particle ID
| class="col4" | The latest version of the protocol is 8
+
| Int
|- class="row2"
+
| The particle ID listed in [[#Particle|the particle data type]].
| class="col0 centeralign" | Username
+
|-
| class="col1 centeralign" | string
+
| Long Distance
| class="col2 centeralign" | <code>TkTech</code>
+
| Boolean
| class="col3" | The name of the user attempting to login
+
| If true, particle distance increases from 256 to 65536
|- class="row3"
+
|-
| class="col0 centeralign" | Password
+
| X
| class="col1 centeralign" | string
+
| Double
| class="col2 centeralign" | <code>Password</code>
+
| X position of the particle
| class="col3" | Used to login to password-protected servers
+
|-
|- class="row4"
+
| Y
| class="col0 centeralign" | Map Seed
+
| Double
| class="col1 centeralign" | long
+
| Y position of the particle
| class="col2 centeralign" | <code>0</code>
+
|-
| class="col3" | This value is not required for the client
+
| Z
|- class="row5"
+
| Double
| class="col0 centeralign" | Dimension
+
| Z position of the particle
| class="col1 centeralign" | byte
+
|-
| class="col2 centeralign" | <code>0</code>
+
| Offset X
| class="col3" | This value is not required for the client
+
| Float
|- class="row6"
+
| This is added to the X position after being multiplied by random.nextGaussian()
! class="col0" | Total Size:
+
|-
| class="col1 rightalign" colspan="4" | 18 bytes + length of strings
+
| 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
 +
| Varies
 +
| The variable data listed in [[#Particle|the particle data type]].
 +
|}
  
==== Server to Client ====
+
==== Update Light ====
  
Sent by the server if it accepts the clients [[#Login_Request_.280x01.29|login request]]. If it didn't, it'll send a [[#Disconnect.2FKick_.280xFF.29|kick]] instead.
+
Updates light levels for a chunk.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
!colspan="2"| Field Name
! class="col3" | Example
+
!colspan="2"| Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="5" | 0x01
+
|rowspan="10"| 0x25
| class="col1 centeralign" | Entity ID
+
|rowspan="10"| Play
| class="col2 centeralign" | int
+
|rowspan="10"| Client
| class="col3 centeralign" | <code>1298</code>
+
|colspan="2"| Chunk X
| class="col4" | The Players Entity ID
+
|colspan="2"| VarInt
|- class="row2"
+
| Chunk coordinate (block coordinate divided by 16, rounded down)
| class="col0 centeralign" | Unknown
+
|-
| class="col1 centeralign" | string
+
|colspan="2"| Chunk Z
| class="col2 centeralign" | n/a
+
|colspan="2"| VarInt
| class="col3" | Not yet used (Possibly the server name?)
+
| Chunk coordinate (block coordinate divided by 16, rounded down)
|- class="row3"
+
|-
| class="col0 centeralign" | Unknown
+
|colspan="2"| Sky Light Mask
| class="col1 centeralign" | string
+
|colspan="2"| VarInt
| class="col2 centeralign" | n/a
+
| Mask containing 18 bits, with the lowest bit corresponding to chunk section -1 (in the void, y=-16 to y=-1) and the highest bit for chunk section 16 (above the world, y=256 to y=271)
| class="col3" | Not yet used (Possibly the MOTD? )
+
|-
|- class="row4"
+
|colspan="2"| Block Light Mask
| class="col0 centeralign" | Map Seed
+
|colspan="2"| VarInt
| class="col1 centeralign" | long
+
| Mask containing 18 bits, with the same order as sky light
| class="col2 centeralign" | <code>971768181197178410</code>
+
|-
| class="col3" | Used for map generation (Possibly biome determination?)
+
|colspan="2"| Empty Sky Light Mask
|- class="row5"
+
|colspan="2"| VarInt
| class="col0 centeralign" | Dimension
+
| Mask containing 18 bits, which indicates sections that have 0 for all their sky light values.  If a section is set in both this mask and the main sky light mask, it is ignored for this mask and it is included in the sky light arrays (the notchian server does not create such masks).  If it is only set in this mask, it is not included in the sky light arrays.
| class="col1 centeralign" | byte
+
|-
| class="col2 centeralign" | <code>0</code>
+
|colspan="2"| Empty Block Light Mask
| class="col3" | Used for specifying the players dimension -1 for hell, 0 otherwise
+
|colspan="2"| VarInt
|- class="row6"
+
| Mask containing 18 bits, which indicates sections that have 0 for all their block light values.  If a section is set in both this mask and the main block light mask, it is ignored for this mask and it is included in the block light arrays (the notchian server does not create such masks).  If it is only set in this mask, it is not included in the block light arrays.
! class="col0" | Total Size:
+
|-
| class="col1 rightalign" colspan="4" | 18 bytes + length of strings
+
|rowspan="2"| Sky Light arrays
|}
+
| Length
 +
|rowspan="2"| Array
 +
| VarInt
 +
| Length of the following array in bytes (always 2048)
 +
|-
 +
| Sky Light array
 +
| Array of 2048 bytes
 +
| There is 1 array for each bit set to true in the sky light mask, starting with the lowest value.  Half a byte per light value.
 +
|-
 +
|rowspan="2"| Block Light arrays
 +
| Length
 +
|rowspan="2"| Array
 +
| VarInt
 +
| Length of the following array in bytes (always 2048)
 +
|-
 +
| Block Light array
 +
| Array of 2048 bytes
 +
| There is 1 array for each bit set to true in the block light mask, starting with the lowest value.  Half a byte per light value.
 +
|}
  
=== Handshake (0x02) ===
+
Individual block or sky light arrays are is given for each block with increasing x coordinates, within rows of increasing z coordinates, within layers of increasing y coordinates. Even-indexed items (those with an even x coordinate, starting at 0) are packed into the low bits, odd-indexed into the high bits.
  
==== Client to Server ====
+
==== Join Game ====
  
This is the first packet sent when the client connects and is used for [[Authentication]].
+
See [[Protocol Encryption]] for information on logging in.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" | 0x02
+
|rowspan="9"| 0x26
| class="col1 centeralign" | Username
+
|rowspan="9"| Play
| class="col2 centeralign" | string
+
|rowspan="9"| Client
| class="col3 centeralign" | <code>TkTech</code>
+
| Entity ID
| class="col4" | The username of the player attempting to connect
+
| Int
|- class="row2"
+
| The player's Entity ID (EID)
! class="col0" | Total Size:
+
|-
| class="col1 rightalign" colspan="4" | 3 bytes + length of strings
+
| Gamemode
|}
+
| Unsigned Byte
 +
| 0: Survival, 1: Creative, 2: Adventure, 3: Spectator. Bit 3 (0x8) is the hardcore flag.
 +
|-
 +
| Dimension
 +
| Int Enum
 +
| -1: Nether, 0: Overworld, 1: End; also, note that this is not a VarInt but instead a regular int.
 +
|-
 +
| 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 {{Minecraft Wiki|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
 +
|}
  
==== Server to Client ====
+
==== Map Data ====
  
This is the first packet sent when the client connects and is used for [[Authentication]]. If the hash is '-', then the client continues without doing name authentication. If the hash is a '+', the client sends the server password in the [[#Login_Request_.280x01.29|login request]]. (Note that this hash, as of the latest version of the Beta server, is a randomly generated long in hexadecimal form, and has nothing to do with the client or the server he is connected to)
+
Updates a rectangular area on a {{Minecraft Wiki|map}} item.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
!colspan="2"| Field Name
! class="col3" | Example
+
!colspan="2"| Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" | 0x02
+
|rowspan="17"| 0x27
| class="col1 centeralign" | Connection Hash
+
|rowspan="17"| Play
| class="col2 centeralign" | string
+
|rowspan="17"| Client
| class="col3 rightalign" | <code>2e66f1dc032ab5f0</code>
+
|colspan="2"| Map ID
| class="col4" | A unique, per-connection hash, '''or''' '-', '''or''' '+'
+
|colspan="2"| VarInt
|- class="row2"
+
| Map ID of the map being modified
! class="col0" | Total Size:
+
|-
| class="col1 rightalign" colspan="4" | 3 bytes + length of strings
+
|colspan="2"| Scale
|}
+
|colspan="2"| 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)
 +
|-
 +
|colspan="2"| Tracking Position
 +
|colspan="2"| Boolean
 +
| Specifies whether player and item frame icons are shown
 +
|-
 +
|colspan="2"| Locked
 +
|colspan="2"| Boolean
 +
| True if the map has been locked in a cartography table
 +
|-
 +
|colspan="2"| Icon Count
 +
|colspan="2"| VarInt
 +
| Number of elements in the following array
 +
|-
 +
|rowspan="6"| Icon
 +
| Type
 +
|rowspan="6"| Array
 +
| VarInt enum
 +
| See below
 +
|-
 +
| X
 +
| Byte
 +
| Map coordinates: -128 for furthest left, +127 for furthest right
 +
|-
 +
| Z
 +
| Byte
 +
| Map coordinates: -128 for highest, +127 for lowest
 +
|-
 +
| Direction
 +
| Byte
 +
| 0-15
 +
|-
 +
| Has Display Name
 +
| Boolean
 +
|
 +
|-
 +
| Display Name
 +
| Optional [[Chat]]
 +
| Only present if previous Boolean is true
 +
|-
 +
|colspan="2"| Columns
 +
|colspan="2"| Unsigned Byte
 +
| Number of columns updated
 +
|-
 +
|colspan="2"| Rows
 +
|colspan="2"| Optional Byte
 +
| Only if Columns is more than 0; number of rows updated
 +
|-
 +
|colspan="2"| X
 +
|colspan="2"| Optional Byte
 +
| Only if Columns is more than 0; x offset of the westernmost column
 +
|-
 +
|colspan="2"| Z
 +
|colspan="2"| Optional Byte
 +
| Only if Columns is more than 0; z offset of the northernmost row
 +
|-
 +
|colspan="2"| Length
 +
|colspan="2"| Optional VarInt
 +
| Only if Columns is more than 0; length of the following array
 +
|-
 +
|colspan="2"| Data
 +
|colspan="2"| Optional Array of Unsigned Byte
 +
| Only if Columns is more than 0; see {{Minecraft Wiki|Map item format}}
 +
|}
  
=== Chat Message (0x03) ===
+
For icons, a direction of 0 is a vertical icon and increments by 22.5&deg; (360/16).
  
A message from the client to the server, or the server to the client. The actual handling of chat messages is variable and depends on the server and client; there are no ''de facto'' standards yet.
+
Types are based off of rows and columns in <code>map_icons.png</code>:
  
The Alpha server will check the message to see if it begins with a '/'. If it doesn't, the username of the sender is prepended and sent to all other clients (including the original sender). If it does, the server assumes it to be a command and attempts to process it. A message longer than 100 characters will cause the server to kick the client. This limits the chat message packet length to 103 bytes. Note that this limit does not apply to incoming chat messages as the server may have prepended other information, not limited to, but usually including, a username.
+
{| class="wikitable"
 +
|-
 +
! 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
 +
|}
  
For more information, see [[Chat]].
+
==== Trade List ====
 +
 
 +
The list of trades a villager NPC is offering.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
!colspan="2"| Field Name
! class="col3" | Example
+
!colspan="2"| Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" | 0x03
+
|rowspan="18"| 0x28
| class="col1 centeralign" | Message
+
|rowspan="18"| Play
| class="col2 centeralign" | string
+
|rowspan="18"| Client
| class="col3 centeralign" | <code>&lt;Bob&gt; Hello World!</code>
+
|-
| class="col4" | User input '''must''' be sanitized server-side
+
| colspan="2" | Window ID
|- class="row2"
+
| colspan="2" | VarInt
! class="col0" | Total Size:
+
| The ID of the window that is open; this is an int rather than a byte.
| class="col1 rightalign" colspan="4" | 3 bytes + length of strings
+
|-
|}
+
| colspan="2" | Size
 +
| colspan="2" | Byte
 +
| The number of trades in the following array
 +
|-
 +
| rowspan="11" | Trades
 +
| Input item 1
 +
| rowspan="11" | Array
 +
| [[Slot]]
 +
| The first item the villager is buying
 +
|-
 +
| Output item
 +
| [[Slot]]
 +
| The item the villager is selling
 +
|-
 +
| Has second item
 +
| Boolean
 +
| Whether there is a second item
 +
|-
 +
| Input item 2
 +
| Optional [[Slot]]
 +
| The second item the villager is buying; only present if they have a second item.
 +
|-
 +
| Trade disabled
 +
| Boolean
 +
| True if the trade is disabled; false if the trade is enabled.
 +
|-
 +
| Number of trade uses
 +
| Integer
 +
| Number of times the trade has been used so far
 +
|-
 +
| Maximum number of trade uses
 +
| Integer
 +
| Number of times this trade can be used
 +
|-
 +
| XP
 +
| Integer
 +
|
 +
|-
 +
| Special Price
 +
| Integer
 +
|
 +
|-
 +
| Price Multiplier
 +
| Float
 +
|
 +
|-
 +
| Demand
 +
| Integer
 +
|
 +
|-
 +
|colspan="2"| Villager level
 +
|colspan="2"| VarInt
 +
| Appears on the trade GUI; meaning comes from the translation key <code>merchant.level.</code> + level.
 +
1: Novice, 2: Apprentice, 3: Journeyman, 4: Expert, 5: Master
 +
|-
 +
|colspan="2"| Experience
 +
|colspan="2"| VarInt
 +
| Total experience for this villager (always 0 for the wandering trader)
 +
|-
 +
|colspan="2"| Is regular villager
 +
|colspan="2"| Boolean
 +
| True if this is a regular villager; false for the wandering trader.  When false, hides the villager level and some other GUI elements.
 +
|-
 +
|colspan="2"| Can restock
 +
|colspan="2"| Boolean
 +
| True for regular villagers and false for the wandering trader.  If true, the "Villagers restock up to two times per day." message is displayed when hovering over disabled trades.
 +
|}
  
=== Time Update (0x04) ===
+
[[File:1.14-merchant-slots.png|thumb|The merchant UI, for reference]]
 +
{{-}}
  
'''Server to Client only'''
+
==== Entity Position ====
  
Time is based on ticks, where 20 ticks happen every second. There are 24000 ticks in a day, making Minecraft days exactly 20 minutes long.
+
This packet is sent by the server when an entity moves less then 8 blocks; if an entity moves more than 8 blocks [[#Entity Teleport|Entity Teleport]] should be sent instead.
 +
 
 +
This packet allows at most 8 blocks movement in any direction, because short range is from -32768 to 32767. And <code>32768 / (128 * 32)</code> = 8.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="5"| 0x29
 +
|rowspan="5"| Play
 +
|rowspan="5"| Client
 +
| Entity ID
 +
| VarInt
 +
|
 +
|-
 +
| Delta X
 +
| Short
 +
| Change in X position as <code>(currentX * 32 - prevX * 32) * 128</code>
 +
|-
 +
| Delta Y
 +
| Short
 +
| Change in Y position as <code>(currentY * 32 - prevY * 32) * 128</code>
 +
|-
 +
| Delta Z
 +
| Short
 +
| Change in Z position as <code>(currentZ * 32 - prevZ * 32) * 128</code>
 +
|-
 +
| On Ground
 +
| Boolean
 +
|
 +
|}
 +
 
 +
==== Entity Position and Rotation ====
 +
 
 +
This packet is sent by the server when an entity rotates and moves. Since a short range is limited from -32768 to 32767, and movement is offset of fixed-point numbers, this packet allows at most 8 blocks movement in any direction. (<code>-32768 / (32 * 128) == -8</code>)
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="7"| 0x2A
 +
|rowspan="7"| Play
 +
|rowspan="7"| Client
 +
| Entity ID
 +
| VarInt
 +
|
 +
|-
 +
| Delta X
 +
| Short
 +
| Change in X position as <code>(currentX * 32 - prevX * 32) * 128</code>
 +
|-
 +
| Delta Y
 +
| Short
 +
| Change in Y position as <code>(currentY * 32 - prevY * 32) * 128</code>
 +
|-
 +
| Delta Z
 +
| Short
 +
| Change in Z position as <code>(currentZ * 32 - prevZ * 32) * 128</code>
 +
|-
 +
| Yaw
 +
| Angle
 +
| New angle, not a delta
 +
|-
 +
| Pitch
 +
| Angle
 +
| New angle, not a delta
 +
|-
 +
| On Ground
 +
| Boolean
 +
|
 +
|}
  
The time of day is based on the timestamp modulo 24000. 0 is sunrise, 6000 is noon, 12000 is sunset, and 18000 is midnight.
+
==== Entity Rotation ====
  
The default SMP server increments the time by <code>20</code> every second.
+
This packet is sent by the server when an entity rotates.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" | 0x04
+
|rowspan="4"| 0x2B
| class="col1 centeralign" | Time
+
|rowspan="4"| Play
| class="col2 centeralign" | long
+
|rowspan="4"| Client
| class="col3 centeralign" | <code></code>
+
| Entity ID
| class="col4 centeralign" | The world (or region) time, in ticks
+
| VarInt
|- class="row2"
+
|  
! class="col0" | Total Size:
+
|-
| class="col1 rightalign" colspan="4" | 9 bytes
+
| Yaw
|}
+
| Angle
 +
| New angle, not a delta
 +
|-
 +
| Pitch
 +
| Angle
 +
| New angle, not a delta
 +
|-
 +
| On Ground
 +
| Boolean
 +
|  
 +
|}
 +
 
 +
==== Entity Movement ====
  
=== Entity Equipment (0x05) ===
+
This packet may be used to initialize an entity.
  
After each "Named Entity Spawn", there will be five of these packets for the equipped item and armor.  If there are changes in visible equipment, another one of these is sent.
+
For player entities, either this packet or any move/look packet is sent every game tick. So the meaning of this packet is basically that the entity did not move/look since the last such packet.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="4" | 0x05
+
|rowspan="1"| 0x2C
| class="col1 centeralign" | Entity ID
+
|rowspan="1"| Play
| class="col2 centeralign" | int
+
|rowspan="1"| Client
| class="col3 centeralign" | 0x00010643
+
| Entity ID
| class="col4" | Named Entity ID
+
| VarInt
|- class="row2"
+
|  
| class="col0 centeralign" | Slot
+
|}
| class="col1 centeralign" | short
+
 
| class="col2 centeralign" | 4
+
==== Vehicle Move (clientbound) ====
| class="col3" | Equipment slot: 0=held, 1-4=armor slot
 
|- class="row3"
 
| class="col0 centeralign" | Item ID
 
| class="col1 centeralign" | short
 
| class="col2 centeralign" | -1
 
| class="col3" | Equipped item (-1 for empty slot)
 
|- class="row4"
 
| class="col0 centeralign" | ???
 
| class="col1 centeralign" | short
 
| class="col2 centeralign" |
 
| class="col3" | Damage?
 
|- class="row5"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 11 bytes
 
|}
 
  
=== Spawn Position (0x06) ===
+
Note that all fields use absolute positioning and do not allow for relative positioning.
  
'''Server to Client only'''
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="5"| 0x2D
 +
|rowspan="5"| Play
 +
|rowspan="5"| Client
 +
| X
 +
| Double
 +
| Absolute position (X coordinate)
 +
|-
 +
| Y
 +
| Double
 +
| Absolute position (Y coordinate)
 +
|-
 +
| Z
 +
| Double
 +
| Absolute position (Z coordinate)
 +
|-
 +
| Yaw
 +
| Float
 +
| Absolute rotation on the vertical axis, in degrees
 +
|-
 +
| Pitch
 +
| Float
 +
| Absolute rotation on the horizontal axis, in degrees
 +
|}
  
Sent by the server after login to specify the coordinates of the spawn point (the point at which players spawn at, and which the compass points to). It can be sent at any time to update the point compasses point at.
+
==== Open Book ====
 +
 
 +
Sent when a player right clicks with a signed book. This tells the client to open the book GUI.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="3" | 0x06
+
|rowspan="1"| 0x2E
| class="col1 centeralign" | X
+
|rowspan="1"| Play
| class="col2 centeralign" | int
+
|rowspan="1"| Client
| class="col3 centeralign" | <code>117</code>
+
| Hand
| class="col4 centeralign" | Spawn X in block coordinates
+
| VarInt enum
|- class="row2"
+
| 0: Main hand, 1: Off hand
| class="col0 centeralign" | Y
+
|}
| class="col1 centeralign" | int
 
| class="col2 centeralign" | <code>70</code>
 
| class="col3 centeralign" | Spawn Y in block coordinates
 
|- class="row3"
 
| class="col0 centeralign" | Z
 
| class="col1 centeralign" | int
 
| class="col2 centeralign" | <code>-46</code>
 
| class="col3 centeralign" | Spawn Z in block coordinates
 
|- class="row4"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 13 bytes
 
|}
 
  
=== Use Entity? (0x07) ===
+
==== Open Window ====
This packet is new to version 4 of the protocol, and is believed to be Use Entity. This packet is sent from the client to the server when the client attacks or right-clicks another entity.
 
  
(This packet data values are not fully verified)
+
This is sent to the client when it should open an inventory, such as a chest, workbench, or furnace. This message is not sent anywhere for clients opening their own inventory.  For horses, use [[#Open Horse Window|Open Horse Window]].
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="3" | 0x07
+
|rowspan="3"| 0x2F
| class="col1 centeralign" | User
+
|rowspan="3"| Play
| class="col2 centeralign" | int
+
|rowspan="3"| Client
| class="col3 centeralign" | <code>1298</code>
+
| Window ID
| class="col4" |
+
| VarInt
The entity of the player (ignored by the server)
+
| A unique id number for the window to be displayed. Notchian server implementation is a counter, starting at 1.
|- class="row2"
+
|-
| class="col0 centeralign" | Target
+
| Window Type
| class="col1 centeralign" | int
+
| VarInt
| class="col2 centeralign" | <code>1805</code>
+
| The window type to use for display. Contained in the <code>minecraft:menu</code> regisry; see [[Inventory]] for the different values.
| class="col3" |
+
|-
The entity the player is interacting with
+
| Window Title
|- class="row3"
+
| [[Chat]]
| class="col0 centeralign" | Left-click?
+
| The title of the window
| class="col1 centeralign" | bool
+
|}
| class="col2 centeralign" | <code>true</code>
 
| class="col3" |
 
Seems to be <code>true</code> when the player is pointing at an entity and left-clicking and <code>false</code> when right-clicking.
 
|- class="row4"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 10 bytes
 
|}
 
  
=== Update Health (0x08) ===
+
==== Open Sign Editor ====
  
'''Server to Client only'''
+
Sent when the client has placed a sign and is allowed to send [[#Update Sign|Update Sign]].  There must already be a sign at the given location (which the client does not do automatically) - send a [[#Block Change|Block Change]] first.
  
Sent by the server to update/set the health of the player it is sent to. Added in protocol version 5.
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="1"| 0x30
 +
|rowspan="1"| Play
 +
|rowspan="1"| Client
 +
| Location
 +
| Position
 +
|
 +
|}
 +
 
 +
==== 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"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" | 0x08
+
|rowspan="2"| 0x31
| class="col1 centeralign" | Health
+
|rowspan="2"| Play
| class="col2 centeralign" | short
+
|rowspan="2"| Client
| class="col3 centeralign" | 20
+
| Window ID
| class="col4" | 0 = dead, 20 = full HP
+
| Byte
|- class="row2"
+
|
! class="col0" | Total Size:
+
|-
| class="col1 rightalign" colspan="4" | 3 bytes
+
| Recipe
|}
+
| Identifier
 +
| A recipe ID
 +
|}
  
[[File:Icon_exclaim.gif|:!:]] The health value may be less than 0 depending on the amount of damage that killed the player. Treat all values ≤ 0 as dead and needing respawn.
+
==== Player Abilities (clientbound) ====
  
=== Respawn (0x09) ===
+
The latter 2 floats are used to indicate the field of view and flying speed respectively, while the first byte is used to determine the value of 4 booleans.
  
Sent by the client when the player presses the "Respawn" button after dying. The server then teleports the user to the spawn point, and sends a respawn packet in response. The client will not leave the respawn screen until it receives a respawn packet.
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="3"| 0x32
 +
|rowspan="3"| Play
 +
|rowspan="3"| Client
 +
| Flags
 +
| Byte
 +
| Bit field, see below
 +
|-
 +
| Flying Speed
 +
| Float
 +
| 0.05 by default
 +
|-
 +
| Field of View Modifier
 +
| Float
 +
| Modifies the field of view, like a speed potion. A Notchian server will use the same value as the movement speed sent in the [[Protocol#Entity_Properties|Entity Properties]] packet, which defaults to 0.1 for players.
 +
|}
 +
 
 +
About the flags:
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
|-
! class="col0" | Packet ID
+
! Field
|- class="row1"
+
! Bit
| class="col0 centeralign" | 0x09
+
|-
|- class="row2"
+
| Invulnerable
! class="col0" | Total Size: 1 bytes
+
| 0x01
|}
+
|-
 +
| Flying
 +
| 0x02
 +
|-
 +
| Allow Flying
 +
| 0x04
 +
|-
 +
| Creative Mode (Instant Break)
 +
  | 0x08
 +
|}
  
=== Player (0x0A) ===
+
==== Combat Event ====
  
'''Client to Server only'''
+
Originally used for metadata for twitch streaming circa 1.8.  Now only used to display the game over screen (with enter combat and end combat completely ignored by the Notchain client)
  
This packet is used to indicate whether the player is on ground (walking/swimming), or airborne (jumping/falling).
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
!colspan="2"| Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="8"| 0x33
 +
|rowspan="8"| Play
 +
|rowspan="8"| Client
 +
|colspan="2"| Event
 +
| VarInt Enum
 +
| Determines the layout of the remaining packet
 +
|-
 +
! Event
 +
! Field Name
 +
!
 +
!
 +
|-
 +
| 0: enter combat
 +
| ''no fields''
 +
| ''no fields''
 +
|
 +
|-
 +
|rowspan="2"| 1: end combat
 +
| Duration
 +
| VarInt
 +
| Length of the combat in ticks.
 +
|-
 +
| Entity ID
 +
| Int
 +
| ID of the primary opponent of the ended combat, or -1 if there is no obvious primary opponent.
 +
|-
 +
|rowspan="3"| 2: entity dead
 +
| Player ID
 +
| VarInt
 +
| Entity ID of the player that died (should match the client's entity ID).
 +
|-
 +
| Entity ID
 +
| Int
 +
| The killing entity's ID, or -1 if there is no obvious killer.
 +
|-
 +
| Message
 +
| [[Chat]]
 +
| The death message
 +
|}
  
When dropping from sufficient height, fall damage is applied when this state goes from False to True. The amount of damage applied is based on the point where it last changed from True to False. Note that there are several movement related packets containing this state.
+
==== Player Info ====
  
This packet was previously referred to as Flying
+
Sent by the server to update the user list (<tab> in the client).
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
!colspan="4"| Field Name
! class="col3" | Example
+
!colspan="3"| Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" | 0x0A
+
|rowspan="19"| 0x34
| class="col1 centeralign" | On Ground
+
|rowspan="19"| Play
| class="col2 centeralign" | bool
+
|rowspan="19"| Client
| class="col3 centeralign" | <code>1</code>
+
|colspan="4"| Action
| class="col4" | <code>True</code> if the client is on the ground, <code>False</code> otherwise
+
|colspan="3"| VarInt
|- class="row2"
+
| Determines the rest of the Player format after the UUID
! class="col0" | Total Size:
+
|-
| class="col1 rightalign" colspan="4" | 2 bytes
+
|colspan="4"| Number Of Players
|}
+
|colspan="3"| VarInt
 +
| Number of elements in the following array
 +
|-
 +
|rowspan="17"| Player
 +
|colspan="3"| UUID
 +
|rowspan="17"| Array
 +
|colspan="2"| UUID
 +
|
 +
|-
 +
! Action
 +
!colspan="2"| Field Name
 +
!colspan="2"|  
 +
!  
 +
|-
 +
|rowspan="10"| 0: add player
 +
|colspan="2"| Name
 +
|colspan="2"| String (16)
 +
|
 +
|-
 +
|colspan="2"| Number Of Properties
 +
|colspan="2"| VarInt
 +
| Number of elements in the following array
 +
|-
 +
|rowspan="4"| Property
 +
| Name
 +
|rowspan="4"| Array
 +
| String (32767)
 +
|
 +
|-
 +
| Value
 +
| String (32767)
 +
|
 +
|-
 +
| Is Signed
 +
| Boolean
 +
|
 +
|-
 +
| Signature
 +
| Optional String (32767)
 +
| Only if Is Signed is true
 +
|-
 +
|colspan="2"| Gamemode
 +
|colspan="2"| VarInt
 +
|
 +
|-
 +
|colspan="2"| Ping
 +
|colspan="2"| VarInt
 +
| Measured in milliseconds
 +
|-
 +
|colspan="2"| Has Display Name
 +
|colspan="2"| Boolean
 +
|
 +
|-
 +
|colspan="2"| Display Name
 +
|colspan="2"| Optional [[Chat]]
 +
| Only if Has Display Name is true
 +
|-
 +
| 1: update gamemode
 +
|colspan="2"| Gamemode
 +
|colspan="2"| VarInt
 +
|
 +
|-  
 +
| 2: update latency
 +
|colspan="2"| Ping
 +
|colspan="2"| VarInt
 +
| Measured in milliseconds
 +
|-
 +
|rowspan="2"| 3: update display name
 +
|colspan="2"| Has Display Name
 +
|colspan="2"| Boolean
 +
|
 +
|-
 +
|colspan="2"| Display Name
 +
|colspan="2"| Optional [[Chat]]
 +
| Only send if Has Display Name is true
 +
|-
 +
| 4: remove player
 +
|colspan="2"| ''no fields''
 +
|colspan="2"| ''no fields''
 +
|
 +
|}
  
=== Player Position (0x0B) ===
+
The Property field looks as in the response of [[Mojang API#UUID -> Profile + Skin/Cape]], except of course using the protocol format instead of JSON. That is, each player will usually have one property with Name “textures” and Value being a base64-encoded JSON string as documented at [[Mojang API#UUID -> Profile + Skin/Cape]]. An empty properties array is also acceptable, and will cause clients to display the player with one of the two default skins depending on UUID.
  
'''Client to Server''' (player-controlled movement).
+
Ping values correspond with icons in the following way:
 +
* A ping that negative (i.e. not known to the server yet) will result in the no connection icon.
 +
* A ping under 150 milliseconds will result in 5 bars
 +
* A ping under 300 milliseconds will result in 4 bars
 +
* A ping under 600 milliseconds will result in 3 bars
 +
* A ping under 1000 milliseconds (1 second) will result in 2 bars
 +
* A ping greater than or equal to 1 second will result in 1 bar.
  
Updates the players XYZ position on the server. If <code>Stance - Y</code> is less than <code>0.1</code> or greater than <code>1.65</code>, the stance is illegal and the client will be kicked with the message “Illegal Stance”.
+
==== Face Player ====
 +
 
 +
Used to rotate the client player to face the given location or entity (for <code>/teleport [<targets>] <x> <y> <z> facing</code>).
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="5" | 0x0B
+
|rowspan="8"| 0x35
| class="col1 centeralign" | X
+
|rowspan="8"| Play
| class="col2 centeralign" | double
+
|rowspan="8"| Client
| class="col3 rightalign" | <code>102.809</code>
+
|-
| class="col4" | Absolute position
+
| Feet/eyes
|- class="row2"
+
| VarInt enum
| class="col0 centeralign" | Y
+
| Values are feet=0, eyes=1.  If set to eyes, aims using the head position; otherwise aims using the feet position.
| class="col1 centeralign" | double
+
|-
| class="col2 centeralign" | <code>70.00</code>
+
| Target x
| class="col3" | Absolute position
+
| Double
|- class="row3"
+
| x coordinate of the point to face towards
| class="col0 centeralign" | Stance
+
|-
| class="col1 centeralign" | double
+
| Target y
| class="col2 centeralign" | <code>71.62</code>
+
| Double
| class="col3" | Used to modify the players bounding box when going up stairs, crouching, etc…
+
| y coordinate of the point to face towards
|- class="row4"
+
|-
| class="col0 centeralign" | Z
+
| Target z
| class="col1 centeralign" | double
+
| Double
| class="col2 centeralign" | <code>68.30</code>
+
| z coordinate of the point to face towards
| class="col3" | Absolute position
+
|-
|- class="row5"
+
| Is entity
| class="col0 centeralign" | On Ground
+
| Boolean
| class="col1 centeralign" | bool
+
| If true, additional information about an entity is provided.
| class="col2 centeralign" | <code>1</code>
+
|-
| class="col3" |
+
| Entity ID
Derived from packet [[#Player_.280x0A.29|0x0A]]
+
| Optional VarInt
|- class="row6"
+
| Only if is entity is true &mdash; the entity to face towards
! class="col0" | Total Size:
+
|-
| class="col1 rightalign" colspan="4" | 34 bytes
+
| 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.
  
=== Player Look (0x0C) ===
+
==== Player Position And Look (clientbound) ====  
  
'''Client to Server''' (player-controlled movement).
+
Updates the player's position on the server. This packet will also close the “Downloading Terrain” screen when joining/respawning.
  
[[File:Minecraft-trig-yaw.png|thumb|The unit circle for yaw]]
+
If the distance between the last known position of the player on the server and the new position set by this packet is greater than 100 meters, the client will be kicked for “You moved too quickly :( (Hacking?)”.
  
Updates the direction the player is looking in.
+
Also if the fixed-point number of X or Z is set greater than <code>3.2E7D</code> the client will be kicked for “Illegal position”.
  
Yaw is measured in degrees, and does not follow classical trigonometry rules. The unit circle of yaw on the xz-plane starts at (0, 1) and turns backwards towards (-1, 0), or in other words, it turns clockwise instead of counterclockwise. Additionally, yaw is not clamped to between 0 and 360 degrees; any number is valid, including negative numbers and numbers greater than 360.
+
Yaw is measured in degrees, and does not follow classical trigonometry rules. The unit circle of yaw on the XZ-plane starts at (0, 1) and turns counterclockwise, with 90 at (-1, 0), 180 at (0, -1) and 270 at (1, 0). Additionally, yaw is not clamped to between 0 and 360 degrees; any number is valid, including negative numbers and numbers greater than 360.
  
 
Pitch is measured in degrees, where 0 is looking straight ahead, -90 is looking straight up, and 90 is looking straight down.
 
Pitch is measured in degrees, where 0 is looking straight ahead, -90 is looking straight up, and 90 is looking straight down.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="3" | 0x0C
+
|rowspan="7"| 0x36
| class="col1 centeralign" | Yaw
+
|rowspan="7"| Play
| class="col2 centeralign" | float
+
|rowspan="7"| Client
| class="col3 centeralign" | <code>0.00</code>
+
| X
| class="col4" | Absolute rotation on the X Axis, in degrees
+
| Double
|- class="row2"
+
| Absolute or relative position, depending on Flags
| class="col0 centeralign" | Pitch
+
|-
| class="col1 centeralign" | float
+
| Y
| class="col2 centeralign" | <code>0.00</code>
+
| Double
| class="col3" | Absolute rotation on the Y Axis, in degrees
+
| Absolute or relative position, depending on Flags
|- class="row3"
+
|-
| class="col0 centeralign" | On Ground
+
| Z
| class="col1 centeralign" | bool
+
| Double
| class="col2 centeralign" | <code>1</code>
+
| Absolute or relative position, depending on Flags
| class="col3" |
+
|-
Derived from packet [[#Player_.280x0A.29|0x0A]]
+
| Yaw
|- class="row4"
+
| Float
! class="col0" | Total Size:
+
| Absolute or relative rotation on the X axis, in degrees
| class="col1 rightalign" colspan="4" | 10 bytes
+
|-
|}
+
| Pitch
 +
| Float
 +
| Absolute or relative rotation on the Y axis, in degrees
 +
|-
 +
| Flags
 +
| Byte
 +
| Bit field, see below
 +
|-
 +
| Teleport ID
 +
| VarInt
 +
| Client should confirm this packet with [[#Teleport Confirm|Teleport Confirm]] containing the same Teleport ID
 +
|}
 +
 
 +
About the Flags field:
  
=== Player Position &amp; Look (0x0D) ===
+
<Dinnerbone> It's a bitfield, X/Y/Z/Y_ROT/X_ROT. If X is set, the x value is relative and not absolute.
  
A combination of [[#Player_Look_.280x0C.29|Player Look]] and [[#Player_Position_.280x0B.29|Player position]].
+
{| class="wikitable"
 +
|-
 +
! Field
 +
! Bit
 +
|-
 +
| X
 +
| 0x01
 +
|-
 +
| Y
 +
| 0x02
 +
|-
 +
| Z
 +
| 0x04
 +
|-
 +
| Y_ROT
 +
| 0x08
 +
|-
 +
| X_ROT
 +
| 0x10
 +
|}
  
==== Client to Server ====
+
==== Unlock Recipes ====
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="7" | 0x0D
+
|rowspan="10"| 0x37
| class="col1 centeralign" | X
+
|rowspan="10"| Play
| class="col2 centeralign" | double
+
|rowspan="10"| Client
| class="col3 centeralign" | <code>6.5</code>
+
|-
| class="col4" | Absolute position
+
| Action
|- class="row2"
+
| VarInt
| class="col0 centeralign" | Stance
+
| 0: init, 1: add, 2: remove
| class="col1 centeralign" | double
+
|-
| class="col2 centeralign" | <code>67.240000009536743</code>
+
| Crafting Recipe Book Open
| class="col3" | Used to modify the players bounding box when going up stairs, crouching, etc…
+
| Boolean
|- class="row3"
+
| If true, then the crafting recipe book will be open when the player opens its inventory.
| class="col0 centeralign" | Y
+
|-
| class="col1 centeralign" | double
+
| Crafting Recipe Book Filter Active
| class="col2 centeralign" | <code>65.620000004768372</code>
+
| Boolean
| class="col3" | Absolute position
+
| If true, then the filtering option is active when the players opens its inventory.
|- class="row4"
+
|-
| class="col0 centeralign" | Z
+
| Smelting Recipe Book Open
| class="col1 centeralign" | double
+
| Boolean
| class="col2 centeralign" | <code>7.5</code>
+
| If true, then the smelting recipe book will be open when the player opens its inventory.
| class="col3" | Absolute position
+
|-
|- class="row5"
+
| Smelting Recipe Book Filter Active
| class="col0 centeralign" | Yaw
+
| Boolean
| class="col1 centeralign" | float
+
| If true, then the filtering option is active when the players opens its inventory.
| class="col2 centeralign" | <code>0.0</code>
+
|-
| class="col3" | Absolute rotation on the X Axis
+
| Array size 1
|- class="row6"
+
| VarInt
| class="col0 centeralign" | Pitch
+
| Number of elements in the following array
| class="col1 centeralign" | float
+
|-
| class="col2 centeralign" | <code>0.0</code>
+
| Recipe IDs
| class="col3" | Absolute rotation on the Y Axis
+
| Array of Identifier
|- class="row7"
+
|
| class="col0 centeralign" | On Ground
+
|-
| class="col1 centeralign" | bool
+
| Array size 2
| class="col2 centeralign" | <code>0</code>
+
| Optional VarInt
| class="col3" |
+
| Number of elements in the following array, only present if mode is 0 (init)
Derived from packet [[#Player_.280x0A.29|0x0A]]
+
|-
|- class="row8"
+
| Recipe IDs
! class="col0" | Total Size:
+
| Optional Array of Identifier, only present if mode is 0 (init)
| class="col1 rightalign" colspan="4" | 42 bytes
+
|
|}
+
|}
 +
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.
 +
 
 +
==== Destroy Entities ====
  
==== Server to Client ====
+
Sent by the server when a list of entities is to be destroyed on the client.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="7" | 0x0D
+
|rowspan="2"| 0x38
| class="col1 centeralign" | X
+
|rowspan="2"| Play
| class="col2 centeralign" | double
+
|rowspan="2"| Client
| class="col3 centeralign" | <code>6.5</code>
+
| Count
| class="col4" | Absolute position
+
| VarInt
|- class="row2"
+
| Number of elements in the following array
| class="col0 centeralign" | Y
+
|-
| class="col1 centeralign" | double
+
| Entity IDs
| class="col2 centeralign" | <code>65.620000004768372</code>
+
| Array of VarInt
| class="col3" | Absolute position
+
| The list of entities of destroy
|- class="row3"
+
|}
| class="col0 centeralign" | Stance
 
| class="col1 centeralign" | double
 
| class="col2 centeralign" | <code>67.240000009536743</code>
 
| class="col3" | Used to modify the players bounding box when going up stairs, crouching, etc…
 
|- class="row4"
 
| class="col0 centeralign" | Z
 
| class="col1 centeralign" | double
 
| class="col2 centeralign" | <code>7.5</code>
 
| class="col3" | Absolute position
 
|- class="row5"
 
| class="col0 centeralign" | Yaw
 
| class="col1 centeralign" | float
 
| class="col2 centeralign" | <code>0.0</code>
 
| class="col3" | Absolute rotation on the X Axis
 
|- class="row6"
 
| class="col0 centeralign" | Pitch
 
| class="col1 centeralign" | float
 
| class="col2 centeralign" | <code>0.0</code>
 
| class="col3" | Absolute rotation on the Y Axis
 
|- class="row7"
 
| class="col0 centeralign" | On Ground
 
| class="col1 centeralign" | bool
 
| class="col2 centeralign" | <code>0</code>
 
| class="col3" |
 
Derived from packet [[#Player_.280x0A.29|0x0A]]
 
|- class="row8"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 42 bytes
 
|}
 
  
[[File:Icon_exclaim.gif|:!:]] Note that this packet differs from client Player & Position Look packet - the Stance and Y are sent in a different order.
+
==== Remove Entity Effect ====
  
[[File:Icon_exclaim.gif|:!:]] Stance and Y seems to be the opposite as in the table (from Client to Server = X, Y, Stance, Z, froom Server to client = X, Stance, Y, Z) please confirm !
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x39
 +
|rowspan="2"| Play
 +
|rowspan="2"| Client
 +
| Entity ID
 +
| VarInt
 +
|
 +
|-
 +
| Effect ID
 +
| Byte
 +
| See {{Minecraft Wiki|Status effect#List of effects|this table}}
 +
|}
  
[[File:Icon_exclaim.gif|:!:]] When you connect to the official server, it will push a 0x0D packet.  If you do not immediately respond with a 0x0D (or maybe 0x0A-0x0C) packet with similar and valid information, it will have unexpected results, such as map chunks not loading and future 0x0A-0x0D packets being ignored.
+
==== Resource Pack Send ====
  
=== Player Digging (0x0E) ===
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x3A
 +
|rowspan="2"| Play
 +
|rowspan="2"| Client
 +
| URL
 +
| String (32767)
 +
| The URL to the resource pack.
 +
|-
 +
| Hash
 +
| String (40)
 +
| A 40 character hexadecimal and lowercase [[wikipedia:SHA-1|SHA-1]] hash of the resource pack file. (must be lower case in order to work)<br />If it's not a 40 character hexadecimal string, the client will not use it for hash verification and likely waste bandwidth — but it will still treat it as a unique id
 +
|}
 +
 
 +
==== Respawn ====
  
Sent repeatedly as the player mines a block.  A Notchian server only accepts digging packets with coordinates within a 6-unit radius of the player's position.
+
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"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="5" | 0x0E
+
|rowspan="4"| 0x3B
| class="col1 centeralign" | Status
+
|rowspan="4"| Play
| class="col2 centeralign" | byte
+
|rowspan="4"| Client
| class="col3 centeralign" | <code>1</code>
+
| Dimension
| class="col4" | The action the player is taking against the block (see below)
+
| Int Enum
|- class="row2"
+
| -1: The Nether, 0: The Overworld, 1: The End
| class="col0 centeralign" | X
+
|-
| class="col1 centeralign" | int
+
| Hashed seed
| class="col2 centeralign" | <code>32</code>
+
| Long
| class="col3" | Block position
+
| First 8 bytes of the SHA-256 hash of the world's seed.
|- class="row3"
+
|-
| class="col0 centeralign" | Y
+
| Gamemode
| class="col1 centeralign" | byte
+
| Unsigned Byte
| class="col2 centeralign" | <code>64</code>
+
| 0: survival, 1: creative, 2: adventure, 3: spectator. The hardcore flag is not included
| class="col3" | Block position
+
|-
|- class="row4"
+
| Level Type
| class="col0 centeralign" | Z
+
| String (16)
| class="col1 centeralign" | int
+
| Same as [[#Join Game|Join Game]]
| class="col2 centeralign" | <code>32</code>
+
|}
| class="col3 leftalign" | Block position
+
 
|- class="row5"
+
{{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="col0 centeralign" | Face
+
 
| class="col1 centeralign" | byte
+
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.}}
| class="col2 centeralign" | <code>3</code>
+
 
| class="col3" | The face being hit (see below)
+
==== Entity Head Look ====
|- class="row6"
+
 
! class="col0" | Total Size:
+
Changes the direction an entity's head is facing.
| class="col1 rightalign" colspan="4" | 12 bytes
 
|}
 
  
Status can (currently) be one of four values:
+
While sending the Entity Look packet changes the vertical rotation of the head, sending this packet appears to be necessary to rotate the head horizontally.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Meaning
+
! State
! class="col1" | Value
+
! Bound To
|- class="row1"
+
! Field Name
| class="col0 leftalign" | Started digging
+
! Field Type
| class="col1 centeralign" | <code>0</code>
+
! Notes
|- class="row2"
+
|-
| class="col0 leftalign" | Digging
+
|rowspan="2"| 0x3C
| class="col1 centeralign" | <code>1</code>
+
|rowspan="2"| Play
|- class="row3"
+
|rowspan="2"| Client
| class="col0 leftalign" | Stopped digging
+
| Entity ID
| class="col1 centeralign" | <code>2</code>
+
| VarInt
|- class="row4"
+
|  
| class="col0 leftalign" | Block broken
+
|-
| class="col1 centeralign" | <code>3</code>
+
| Head Yaw
|- class="row5"
+
| Angle
| class="col0 leftalign" | Drop item
+
| New angle, not a delta
| class="col1 centeralign" | <code>4</code>
+
|}
|}
+
 
 +
==== Select Advancement Tab ====
 +
 
 +
Sent by the server to indicate that the client should switch advancement tab. Sent either when the client switches tab in the GUI or when an advancement in another tab is made.
  
When the Status value is 2 (Stopped digging) or 4 (Drop item), the coordinates and Face are 0.
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x3D
 +
|rowspan="2"| Play
 +
|rowspan="2"| Client
 +
| Has id
 +
| Boolean
 +
| Indicates if the next field is present
 +
|-
 +
| Optional Identifier
 +
| String (32767)
 +
| See below
 +
|}
  
The face can be one of six values, representing the face being hit:
+
The Identifier can be one of the following:
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Optional Identifier
! class="col0 leftalign" | Value
+
|-
| class="col1 centeralign" | 0
+
| minecraft:story/root
| class="col2 centeralign" | 1
+
|-
| class="col3 centeralign" | 2
+
| minecraft:nether/root
| class="col4 centeralign" | 3
+
|-
| class="col5 centeralign" | 4
+
| minecraft:end/root
| class="col6 centeralign" | 5
+
|-
|- class="row1"
+
| minecraft:adventure/root
! class="col0 leftalign" | Offset
+
|-
| class="col1" | -Y
+
| minecraft:husbandry/root
| class="col2" | +Y
+
|}
| class="col3" | -Z
 
| class="col4" | +Z
 
| class="col5" | -X
 
| class="col6" | +X
 
|}
 
  
=== Player Block Placement (0x0F) ===
+
If no or an invalid identifier is sent, the client will switch to the first tab in the GUI.
  
Sent when the player places a block or (probably) an item. The coordinates sent in this packet are actually the block being built against, which combined with the direction offset tell you where the block should be placed. This is required to correctly position furnaces, torches, etc…
+
==== World Border ====
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
!colspan="2"| Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="7" | 0x0F
+
|rowspan="18"| 0x3E
| class="col1 centeralign" | X
+
|rowspan="18"| Play
| class="col2 centeralign" | int
+
|rowspan="18"| Client
| class="col3 centeralign" | <code>32</code>
+
|colspan="2"| Action
| class="col4" | Block position
+
| VarInt Enum
|- class="row2"
+
| Determines the format of the rest of the packet
| class="col0 centeralign" | Y
+
|-
| class="col1 centeralign" | byte
+
! Action
| class="col2 centeralign" | <code>64</code>
+
! Field Name
| class="col3" | Block position
+
!
|- class="row3"
+
!
| class="col0 centeralign" | Z
+
|-
| class="col1 centeralign" | int
+
| 0: set size
| class="col2 centeralign" | <code>32</code>
+
| Diameter
| class="col3 leftalign" | Block position
+
| Double
|- class="row4"
+
| Length of a single side of the world border, in meters
| class="col0 centeralign" | Direction
+
|-
| class="col1 centeralign" | byte
+
|rowspan="3"| 1: lerp size
| class="col2 centeralign" | <code>3</code>
+
| Old Diameter
| class="col3" | The offset to use for block/item placement (see below)
+
| Double
|- class="row5"
+
| Current length of a single side of the world border, in meters
| class="col0 centeralign" | Block '''or''' Item ID
+
|-
| class="col1 centeralign" | short
+
| New Diameter
| class="col2 centeralign" | <code>1</code>
+
| Double
| class="col3" | The block or item to be placed
+
| Target length of a single side of the world border, in meters
|- class="row6"
+
|-
| class="col0 centeralign" | Amount (opt)
+
| Speed
| class="col1 centeralign" | byte
+
| VarLong
| class="col2 centeralign" | <code>34</code>
+
| Number of real-time ''milli''seconds until New Diameter is reached. It appears that Notchian server does not sync world border speed to game ticks, so it gets out of sync with server lag. If the world border is not moving, this is set to 0.
| class="col3" | The amount of the item in the players hand
+
|-
|- class="row7"
+
|rowspan="2"| 2: set center
| class="col0 centeralign" | Damage (opt)
+
| X
| class="col1 centeralign" | short
+
| Double
| class="col2 centeralign" | <code>83</code>
+
|  
| class="col3" | How much damage the item has taken
+
|-
|- class="row8"
+
| Z
! class="col0" | Total Size:
+
| Double
| class="col1 rightalign" colspan="4" | 13 bytes or 16 bytes
+
|  
|}
+
|-
 +
|rowspan="8"| 3: initialize
 +
| X
 +
| Double
 +
|  
 +
|-
 +
| Z
 +
| Double
 +
|
 +
|-
 +
| Old Diameter
 +
| Double
 +
| Current length of a single side of the world border, in meters
 +
|-
 +
| New Diameter
 +
| Double
 +
| Target length of a single side of the world border, in meters
 +
|-
 +
| Speed
 +
| VarLong
 +
| Number of real-time ''milli''seconds until New Diameter is reached. It appears that Notchian server does not sync world border speed to game ticks, so it gets out of sync with server lag. If the world border is not moving, this is set to 0.
 +
|-
 +
| Portal Teleport Boundary
 +
| VarInt
 +
| Resulting coordinates from a portal teleport are limited to ±value. Usually 29999984.
 +
|-
 +
| Warning Time
 +
| VarInt
 +
| In seconds as set by <code>/worldborder warning time</code>
 +
|-
 +
| Warning Blocks
 +
| VarInt
 +
| In meters
 +
|-
 +
|rowspan="1"| 4: set warning time
 +
| Warning Time
 +
| VarInt
 +
| In seconds as set by <code>/worldborder warning time</code>
 +
|-
 +
|rowspan="1"| 5: set warning blocks
 +
| Warning Blocks
 +
| VarInt
 +
| In meters
 +
|}
 +
 
 +
The Notchian client determines how solid to display the warning by comparing to whichever is higher, the warning distance or whichever is lower, the distance from the current diameter to the target diameter or the place the border will be after warningTime seconds. In pseudocode:
 +
 
 +
<syntaxhighlight lang="java">
 +
distance = max(min(resizeSpeed * 1000 * warningTime, abs(targetDiameter - currentDiameter)), warningDistance);
 +
if (playerDistance < distance) {
 +
    warning = 1.0 - playerDistance / distance;
 +
} else {
 +
    warning = 0.0;
 +
}
 +
</syntaxhighlight>
 +
 
 +
==== Camera ====
 +
 
 +
Sets the entity that the player renders from. This is normally used when the player left-clicks an entity while in spectator mode.
 +
 
 +
The player's camera will move with the entity and look where it is looking. The entity is often another player, but can be any type of entity.  The player is unable to move this entity (move packets will act as if they are coming from the other entity).
  
If the Block/ItemID field is greater than or equal to 0, then the last 2 bytes (amount and damage) are read. Otherwise, they are not read.
+
If the given entity is not loaded by the player, this packet is ignored.  To return control to the player, send this packet with their entity ID.
When 'placing' (Or more accurately, using) your empty hand, the client sends -1 as the Block/ItemID
 
  
The direction can be one of six values, representing the face the block/item is being placed against:
+
The Notchian server resets this (sends it back to the default entity) whenever the spectated entity is killed or the player sneaks, but only if they were spectating an entity. It also sends this packet whenever the player switches out of spectator mode (even if they weren't spectating an entity).
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0 leftalign" | Value
+
! State
| class="col1 centeralign" | 0
+
! Bound To
| class="col2 centeralign" | 1
+
! Field Name
| class="col3 centeralign" | 2
+
! Field Type
| class="col4 centeralign" | 3
+
! Notes
| class="col5 centeralign" | 4
+
|-
| class="col6 centeralign" | 5
+
|rowspan="1"| 0x3F
|- class="row1"
+
|rowspan="1"| Play
! class="col0 leftalign" | Offset
+
|rowspan="1"| Client
| class="col1" | -Y
+
| Camera ID
| class="col2" | +Y
+
| VarInt
| class="col3" | -Z
+
| ID of the entity to set the client's camera to
| class="col4" | +Z
+
|}
| class="col5" | -X
 
| class="col6" | +X
 
|}
 
  
This packet has a special case where X, Y, Z, and Direction are all -1. This special packet indicates that the currently held item for the player should have its state updated.
+
The notchian also loads certain shaders for given entities:
  
The block or item ID corresponds to whatever the client is currently holding, and the Alpha client sends one of these packets any time a right-click is issued on a surface, so no assumptions can be made about the safety of the ID.
+
* Creeper &rarr; <code>shaders/post/creeper.json</code>
 +
* Spider (and cave spider) &rarr; <code>shaders/post/spider.json</code>
 +
* Enderman &rarr; <code>shaders/post/invert.json</code>
 +
* Anything else &rarr; the current shader is unloaded
  
=== Holding Change (0x10) ===
+
==== Held Item Change (clientbound) ====
  
Sent when the player changes the slot selection
+
Sent to change the player's slot selection.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="1"| 0x40
 +
|rowspan="1"| Play
 +
|rowspan="1"| Client
 +
| Slot
 +
| Byte
 +
| The slot which the player has selected (0–8)
 +
|}
 +
 
 +
==== Update View Position ====
 +
 
 +
{{Need Info|Why is this even needed?  Is there a better name for it?  My guess is that it's something to do with logical behavior with latency, but it still seems weird.}}
 +
 
 +
Updates the client's location.  This is used to determine what chunks should remain loaded and if a chunk load should be ignored; chunks outside of the view distance may be unloaded.
 +
 
 +
Sent whenever the player moves across a chunk border horizontally, and also (according to testing) for any integer change in the vertical axis, even if it doesn't go across a chunk section border.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x41
 +
|rowspan="2"| Play
 +
|rowspan="2"| Client
 +
| Chunk X
 +
| VarInt
 +
| Chunk X coordinate of the player's position
 +
|-
 +
| Chunk Z
 +
| VarInt
 +
| Chunk Z coordinate of the player's position
 +
|}
 +
 
 +
==== Update View Distance ====
 +
 
 +
Sent by the integrated singleplayer server when changing render distance.  Does not appear to be used by the dedicated server, as <code>view-distance</code> in server.properties cannot be changed at runtime.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="1"| 0x42
 +
|rowspan="1"| Play
 +
|rowspan="1"| Client
 +
| View Distance
 +
| VarInt
 +
| Render distance (2-32)
 +
|}
 +
 
 +
==== Display Scoreboard ====
 +
 
 +
This is sent to the client when it should display a scoreboard.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x43
 +
|rowspan="2"| Play
 +
|rowspan="2"| Client
 +
| Position
 +
| Byte
 +
| The position of the scoreboard. 0: list, 1: sidebar, 2: below name, 3 - 18: team specific sidebar, indexed as 3 + team color.
 +
|-
 +
| Score Name
 +
| String (16)
 +
| The unique name for the scoreboard to be displayed.
 +
|}
 +
 
 +
==== Entity Metadata ====
 +
 
 +
Updates one or more [[Entities#Entity Metadata Format|metadata]] properties for an existing entity. Any properties not included in the Metadata field are left unchanged.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x44
 +
|rowspan="2"| Play
 +
|rowspan="2"| Client
 +
| Entity ID
 +
| VarInt
 +
|
 +
|-
 +
| Metadata
 +
| [[Entities#Entity Metadata Format|Entity Metadata]]
 +
|
 +
|}
 +
 
 +
==== Attach Entity ====
 +
 
 +
This packet is sent when an entity has been {{Minecraft Wiki|Lead|leashed}} to another entity.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x45
 +
|rowspan="2"| Play
 +
|rowspan="2"| Client
 +
| Attached Entity ID
 +
| Int
 +
| Attached entity's EID
 +
|-
 +
| Holding Entity ID
 +
| Int
 +
| ID of the entity holding the lead. Set to -1 to detach.
 +
|}
 +
 
 +
==== Entity Velocity ====
 +
 
 +
Velocity is believed to be in units of 1/8000 of a block per server tick (50ms); for example, -1343 would move (-1343 / 8000) = −0.167875 blocks per tick (or −3,3575 blocks per second).
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="4"| 0x46
 +
|rowspan="4"| Play
 +
|rowspan="4"| Client
 +
| Entity ID
 +
| VarInt
 +
|
 +
|-
 +
| Velocity X
 +
| Short
 +
| Velocity on the X axis
 +
|-
 +
| Velocity Y
 +
| Short
 +
| Velocity on the Y axis
 +
|-
 +
| Velocity Z
 +
| Short
 +
| Velocity on the Z axis
 +
|}
 +
 
 +
==== Entity Equipment ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="3"| 0x47
 +
|rowspan="3"| Play
 +
|rowspan="3"| Client
 +
| Entity ID
 +
| VarInt
 +
| Entity's EID
 +
|-
 +
| Slot
 +
| VarInt Enum
 +
| Equipment slot. 0: main hand, 1: off hand, 2–5: armor slot (2: boots, 3: leggings, 4: chestplate, 5: helmet)
 +
|-
 +
| Item
 +
| [[Slot Data|Slot]]
 +
|
 +
|}
 +
 
 +
==== Set Experience ====
 +
 
 +
Sent by the server when the client should change experience levels.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="3"| 0x48
 +
|rowspan="3"| Play
 +
|rowspan="3"| Client
 +
| Experience bar
 +
| Float
 +
| Between 0 and 1
 +
|-
 +
| Level
 +
| VarInt
 +
|
 +
|-
 +
| Total Experience
 +
| VarInt
 +
| See {{Minecraft Wiki|Experience#Leveling up}} on the Minecraft Wiki for Total Experience to Level conversion
 +
|}
 +
 
 +
==== Update Health ====
 +
 
 +
Sent by the server to update/set the health of the player it is sent to.
 +
 
 +
Food {{Minecraft Wiki|Food#Hunger vs. Saturation|saturation}} acts as a food “overcharge”. Food values will not decrease while the saturation is over zero. Players logging in automatically get a saturation of 5.0. Eating food increases the saturation as well as the food bar.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="3"| 0x49
 +
|rowspan="3"| Play
 +
|rowspan="3"| Client
 +
| Health
 +
| Float
 +
| 0 or less = dead, 20 = full HP
 +
|-
 +
| Food
 +
| VarInt
 +
| 0–20
 +
|-
 +
| Food Saturation
 +
| Float
 +
| Seems to vary from 0.0 to 5.0 in integer increments
 +
|}
 +
 
 +
==== Scoreboard Objective ====
 +
 
 +
This is sent to the client when it should create a new {{Minecraft Wiki|scoreboard}} objective or remove one.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="4"| 0x4A
 +
|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 Chat
 +
| Only if mode is 0 or 2. The text to be displayed for the score
 +
|-
 +
| Type
 +
| Optional VarInt enum
 +
| Only if mode is 0 or 2. 0 = "integer", 1 = "hearts".
 +
|}
 +
 
 +
==== Set Passengers ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="3"| 0x4B
 +
|rowspan="3"| Play
 +
|rowspan="3"| Client
 +
| Entity ID
 +
| VarInt
 +
| Vehicle's EID
 +
|-
 +
| Passenger Count
 +
| VarInt
 +
| Number of elements in the following array
 +
|-
 +
| Passengers
 +
| Array of VarInt
 +
| EIDs of entity's passengers
 +
|}
 +
 
 +
==== Teams ====
 +
 
 +
Creates and updates teams.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
!colspan="2"| Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="23"| 0x4C
 +
|rowspan="23"| Play
 +
|rowspan="23"| Client
 +
|colspan="2"| Team Name
 +
| String (16)
 +
| A unique name for the team. (Shared with scoreboard).
 +
|-
 +
|colspan="2"| Mode
 +
| Byte
 +
| Determines the layout of the remaining packet
 +
|-
 +
|rowspan="9"| 0: create team
 +
| Team Display Name
 +
| Chat
 +
|
 +
|-
 +
| Friendly Flags
 +
| Byte
 +
| Bit mask. 0x01: Allow friendly fire, 0x02: can see invisible players on same team
 +
|-
 +
| Name Tag Visibility
 +
| String Enum (32)
 +
| <code>always</code>, <code>hideForOtherTeams</code>, <code>hideForOwnTeam</code>, <code>never</code>
 +
|-
 +
| Collision Rule
 +
| String Enum (32)
 +
| <code>always</code>, <code>pushOtherTeams</code>, <code>pushOwnTeam</code>, <code>never</code>
 +
|-
 +
| Team Color
 +
| VarInt enum
 +
| Used to color the name of players on the team; see below
 +
|-
 +
| Team Prefix
 +
| Chat
 +
| Displayed before the names of players that are part of this team
 +
|-
 +
| Team Suffix
 +
| Chat
 +
| Displayed after the names of players that are part of this team
 +
|-
 +
| 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''
 +
|
 +
|-
 +
|rowspan="7"| 2: update team info
 +
| Team Display Name
 +
| Chat
 +
|
 +
|-
 +
| Friendly Flags
 +
| Byte
 +
| Bit mask. 0x01: Allow friendly fire, 0x02: can see invisible entities on same team
 +
|-
 +
| Name Tag Visibility
 +
| String Enum (32)
 +
| <code>always</code>, <code>hideForOtherTeams</code>, <code>hideForOwnTeam</code>, <code>never</code>
 +
|-
 +
| Collision Rule
 +
| String Enum (32)
 +
| <code>always</code>, <code>pushOtherTeams</code>, <code>pushOwnTeam</code>, <code>never</code>
 +
|-
 +
| Team Color
 +
| VarInt enum
 +
| Used to color the name of players on the team; see below
 +
|-
 +
| Team Prefix
 +
| Chat
 +
| Displayed before the names of players that are part of this team
 +
|-
 +
| Team Suffix
 +
| Chat
 +
| Displayed after the names of players that are part of this team
 +
|-
 +
|rowspan="2"| 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.
 +
|-
 +
|rowspan="2"| 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.
 +
|}
 +
 
 +
Team Color: The color of a team defines how the names of the team members are visualized; any formatting code can be used. The following table lists all the possible values.
 +
 
 +
{| class="wikitable"
 +
! ID
 +
! Formatting
 +
|-
 +
| 0-15
 +
| Color formatting, same values as [[Chat]] colors.
 +
|-
 +
| 16
 +
| Obfuscated
 +
|-
 +
| 17
 +
| Bold
 +
|-
 +
| 18
 +
| Strikethrough
 +
|-
 +
| 19
 +
| Underlined
 +
|-
 +
| 20
 +
| Italic
 +
|-
 +
| 21
 +
| Reset
 +
|}
 +
 
 +
==== Update Score ====
 +
 
 +
This is sent to the client when it should update a scoreboard item.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="4"| 0x4D
 +
|rowspan="4"| Play
 +
|rowspan="4"| Client
 +
| Entity Name
 +
| String (40)
 +
| The entity whose score this is.  For players, this is their username; for other entities, it is their UUID.
 +
|-
 +
| Action
 +
| Byte
 +
| 0 to create/update an item. 1 to remove an item.
 +
|-
 +
| Objective Name
 +
| String (16)
 +
| The name of the objective the score belongs to
 +
|-
 +
| Value
 +
| Optional VarInt
 +
| The score to be displayed next to the entry. Only sent when Action does not equal 1.
 +
|}
 +
 
 +
==== Spawn Position ====
 +
 
 +
Sent by the server after login to specify the coordinates of the spawn point (the point at which players spawn at, and which the compass points to). It can be sent at any time to update the point compasses point at.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="1"| 0x4E
 +
|rowspan="1"| Play
 +
|rowspan="1"| Client
 +
| Location
 +
| Position
 +
| Spawn location
 +
|}
 +
 
 +
==== Time Update ====
 +
 
 +
Time is based on ticks, where 20 ticks happen every second. There are 24000 ticks in a day, making Minecraft days exactly 20 minutes long.
 +
 
 +
The time of day is based on the timestamp modulo 24000. 0 is sunrise, 6000 is noon, 12000 is sunset, and 18000 is midnight.
 +
 
 +
The default SMP server increments the time by <code>20</code> every second.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x4F
 +
|rowspan="2"| Play
 +
|rowspan="2"| Client
 +
| World Age
 +
| Long
 +
| In ticks; not changed by server commands
 +
|-
 +
| Time of day
 +
| Long
 +
| The world (or region) time, in ticks. If negative the sun will stop moving at the Math.abs of the time
 +
|}
 +
 
 +
==== Title ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
!colspan="2"| Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="10"| 0x50
 +
|rowspan="10"| Play
 +
|rowspan="10"| Client
 +
|colspan="2"| Action
 +
| VarInt Enum
 +
|
 +
|-
 +
! Action
 +
! Field Name
 +
!
 +
!
 +
|-
 +
| 0: set title
 +
| Title Text
 +
| [[Chat]]
 +
|
 +
|-
 +
| 1: set subtitle
 +
| Subtitle Text
 +
| [[Chat]]
 +
|
 +
|-
 +
| 2: set action bar
 +
| Action bar text
 +
| [[Chat]]
 +
| Displays a message above the hotbar (the same as position 2 in [[#Chat Message (clientbound)|Chat Message (clientbound)]], except that it correctly renders formatted chat. See [https://bugs.mojang.com/browse/MC-119145 MC-119145] for more information.)
 +
|-
 +
|rowspan="3"| 3: set times and display
 +
| Fade In
 +
| Int
 +
| Ticks to spend fading in
 +
|-
 +
| Stay
 +
| Int
 +
| Ticks to keep the title displayed
 +
|-
 +
| Fade Out
 +
| Int
 +
| Ticks to spend out, not when to start fading out
 +
|-
 +
| 4: hide
 +
| ''no fields''
 +
| ''no fields''
 +
|
 +
|-
 +
| 5: reset
 +
| ''no fields''
 +
| ''no fields''
 +
|
 +
|}
 +
 
 +
“Hide” makes the title disappear, but if you run times again the same title will appear. “Reset” erases the text.
 +
 
 +
The title is visible on screen for Fade In + Stay + Fade Out ticks.
 +
 
 +
==== Entity Sound Effect ====
 +
 
 +
Plays a sound effect from an entity.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="5"| 0x51
 +
|rowspan="5"| Play
 +
|rowspan="5"| Client
 +
| Sound ID
 +
| VarInt
 +
| ID of hardcoded sound event ([https://pokechu22.github.io/Burger/1.15.2.html#sounds events] as of 1.15.2)
 +
|-
 +
| Sound Category
 +
| VarInt Enum
 +
| The category that this sound will be played from ([https://gist.github.com/konwboj/7c0c380d3923443e9d55 current categories])
 +
|-
 +
| Entity ID
 +
| VarInt
 +
|
 +
|-
 +
| Volume
 +
| Float
 +
| 1.0 is 100%, capped between 0.0 and 1.0 by Notchian clients
 +
|-
 +
| Pitch
 +
| Float
 +
| Float between 0.5 and 2.0 by Notchian clients
 +
|}
 +
 
 +
==== Sound Effect ====
 +
 
 +
This packet is used to play a number of hardcoded sound events. For custom sounds, use [[#Named Sound Effect|Named Sound Effect]].
 +
 
 +
{{Warning|Numeric sound effect IDs are liable to change between versions}}
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="7"| 0x52
 +
|rowspan="7"| Play
 +
|rowspan="7"| Client
 +
| Sound ID
 +
| VarInt
 +
| ID of hardcoded sound event ([https://pokechu22.github.io/Burger/1.15.2.html#sounds events] as of 1.15.2)
 +
|-
 +
| Sound Category
 +
| VarInt Enum
 +
| The category that this sound will be played from ([https://gist.github.com/konwboj/7c0c380d3923443e9d55 current categories])
 +
|-
 +
| Effect Position X
 +
| Int
 +
| Effect X multiplied by 8 ([[Data types#Fixed-point numbers|fixed-point number]] with only 3 bits dedicated to the fractional part)
 +
|-
 +
| 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
 +
| 1.0 is 100%, capped between 0.0 and 1.0 by Notchian clients
 +
|-
 +
| Pitch
 +
| Float
 +
| Float between 0.5 and 2.0 by Notchian clients
 +
|}
 +
 
 +
==== Stop Sound ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="3"| 0x53
 +
|rowspan="3"| Play
 +
|rowspan="3"| 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|Named Sound Effect]].  If not present, then all sounds are cleared.
 +
|}
 +
 
 +
Categories:
 +
 
 +
{| class="wikitable"
 +
! Name !! Value
 +
|-
 +
| master || 0
 +
|-
 +
| music || 1
 +
|-
 +
| record || 2
 +
|-
 +
| weather || 3
 +
|-
 +
| block || 4
 +
|-
 +
| hostile || 5
 +
|-
 +
| neutral || 6
 +
|-
 +
| player || 7
 +
|-
 +
| ambient || 8
 +
|-
 +
| voice || 9
 +
|}
 +
 
 +
==== Player List Header And Footer ====
 +
 
 +
This packet may be used by custom servers to display additional information above/below the player list. It is never sent by the Notchian server.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x54
 +
|rowspan="2"| Play
 +
|rowspan="2"| Client
 +
| Header
 +
| [[Chat]]
 +
| To remove the header, send a empty translatable component: {"translate":""}
 +
|-
 +
| Footer
 +
| [[Chat]]
 +
| To remove the footer, send a empty translatable component: {"translate":""}
 +
|}
 +
 
 +
==== NBT Query Response ====
 +
 
 +
Sent in response to [[#Query Block NBT|Query Block NBT]] or [[#Query Entity NBT|Query Entity NBT]].
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x55
 +
|rowspan="2"| Play
 +
|rowspan="2"| Client
 +
| Transaction ID
 +
| VarInt
 +
| Can be compared to the one sent in the original query packet.
 +
|-
 +
| NBT
 +
| [[NBT|NBT Tag]]
 +
| The NBT of the block or entity.  May be a TAG_END (0) in which case no NBT is present.
 +
|}
 +
 
 +
==== Collect Item ====
 +
 
 +
Sent by the server when someone picks up an item lying on the ground — its sole purpose appears to be the animation of the item flying towards you. It doesn't destroy the entity in the client memory, and it doesn't add it to your inventory. The server only checks for items to be picked up after each [[#Player Position|Player Position]] (and [[#Player Position And Look|Player Position And Look]]) packet sent by the client. The collector entity can be any entity; it does not have to be a player. The collected entity also can be any entity, but the Notchian server only uses this for items, experience orbs, and the different varieties of arrows.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" | 0x10
+
|rowspan="3"| 0x56
| class="col1 centeralign" | Slot ID
+
|rowspan="3"| Play
| class="col2 centeralign" | short
+
|rowspan="3"| Client
| class="col3 centeralign" | <code>1</code>
+
| Collected Entity ID
| class="col4" | The slot which the player has selected (0-8)
+
| VarInt
|- class="row2"
+
|  
! class="col0" | Total Size:
+
|-
| class="col1 rightalign" colspan="4" | 3 bytes
+
| Collector Entity ID
|}
+
| VarInt
 +
|  
 +
|-  
 +
| Pickup Item Count
 +
| VarInt
 +
| Seems to be 1 for XP orbs, otherwise the number of items in the stack.
 +
|}
  
=== Animation (0x12) ===
+
==== Entity Teleport ====
  
Sent whenever an entity should change animation.
+
This packet is sent by the server when an entity moves more than 8 blocks.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="2" | 0x12
+
|rowspan="7"| 0x57
| class="col1 centeralign" | EID
+
|rowspan="7"| Play
| class="col2 centeralign" | int
+
|rowspan="7"| Client
| class="col3 centeralign" | <code>55534</code>
+
| Entity ID
| class="col4" | Player ID
+
| VarInt
|- class="row2"
+
|
| class="col0 centeralign" | Animate
+
|-
| class="col1 centeralign" | byte
+
| X
| class="col2 centeralign" | <code>1</code>
+
| Double
| class="col3" | Can be <code>0</code> (no animation), <code>1</code> (swing arm), <code>2</code> (damage animation), <code>104</code> (crouch), or <code>105</code> (uncrouch). Getting <code>102</code> somewhat often, too.
+
|  
|- class="row3"
+
|-
! class="col0" | Total Size:
+
| Y
| class="col1 rightalign" colspan="4" | 6 bytes
+
| Double
|}
+
|  
 +
|-
 +
| Z
 +
| Double
 +
|
 +
|-
 +
| Yaw
 +
| Angle
 +
| New angle, not a delta
 +
|-
 +
| Pitch
 +
| Angle
 +
| New angle, not a delta
 +
|-
 +
| On Ground
 +
| Boolean
 +
|  
 +
|}
  
=== Entity Action ??? (0x13) ===
+
==== Advancements ====
  
Sent at least when crouching
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
!colspan="2"| Field Name
 +
!colspan="2"| Field Type
 +
! Notes
 +
|-
 +
|rowspan="9"| 0x58
 +
|rowspan="9"| Play
 +
|rowspan="9"| Client
 +
|colspan="2"| Reset/Clear
 +
|colspan="2"| Boolean
 +
| Whether to reset/clear the current advancements
 +
|-
 +
|colspan="2"| Mapping size
 +
|colspan="2"| VarInt
 +
| Size of the following array
 +
|-
 +
|rowspan="2"| Advancement mapping
 +
| Key
 +
|rowspan="2"| Array
 +
| Identifier
 +
| The identifier of the advancement
 +
|-
 +
| Value
 +
| Advancement
 +
| See below
 +
|-
 +
|colspan="2"| List size
 +
|colspan="2"| VarInt
 +
| Size of the following array
 +
|-
 +
|colspan="2"| Identifiers
 +
|colspan="2"| Array of Identifier
 +
| The identifiers of the advancements that should be removed
 +
|-
 +
|colspan="2"| Progress size
 +
|colspan="2"| VarInt
 +
| Size of the following array
 +
|-
 +
|rowspan="2"| Progress mapping
 +
| Key
 +
|rowspan="2"| Array
 +
| Identifier
 +
| The identifier of the advancement
 +
|-
 +
| Value
 +
| Advancement progress
 +
| See below
 +
|}
 +
 
 +
Advancement structure:
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
!colspan="2"| Field Name
! class="col0" | Packet ID
+
!colspan="2"| Field Type
! class="col1" | Field Name
+
! Notes
! class="col2" | Field Type
+
|-
! class="col3" | Example
+
|colspan="2"| Has parent
! class="col4" | Notes
+
|colspan="2"| Boolean
|- class="row1"
+
| Indicates whether the next field exists.
| class="col0 centeralign" rowspan="2" | 0x13
+
|-
| class="col1 centeralign" | EID
+
|colspan="2"| Parent id
| class="col2 centeralign" | int
+
|colspan="2"| Optional Identifier
| class="col3 centeralign" | <code>55534</code>
+
| The identifier of the parent advancement.
| class="col4" | Player ID
+
|-
|- class="row2"
+
|colspan="2"| Has display
| class="col0 centeralign" | Action
+
|colspan="2"| Boolean
| class="col1 centeralign" | byte
+
| Indicates whether the next field exists
| class="col2 centeralign" | <code>1</code>
+
|-
| class="col3" | Can be <code>1</code> (crouch), or <code>2</code> (uncrouch).
+
|colspan="2"| Display data
|- class="row3"
+
|colspan="2"| Optional advancement display
! class="col0" | Total Size:
+
| See below.
| class="col1 rightalign" colspan="4" | 6 bytes
+
|-
|}
+
|colspan="2"| Number of criteria
 +
|colspan="2"| VarInt
 +
| Size of the following array
 +
|-
 +
|rowspan="2"| Criteria
 +
| Key
 +
|rowspan="2"| Array
 +
| Identifier
 +
| The identifier of the criterion
 +
|-
 +
| Value
 +
| '''Void'''
 +
| There is ''no'' content written here.  Perhaps this will be expanded in the future?
 +
|-
 +
|colspan="2"| Array length
 +
|colspan="2"| VarInt
 +
| Number of arrays in the following array
 +
|-
 +
|rowspan="2"| Requirements
 +
| Array length 2
 +
|rowspan="2"| Array
 +
| VarInt
 +
| Number of elements in the following array
 +
|-
 +
| Requirement
 +
| Array of String
 +
| Array of required criteria
 +
|}
  
=== Named Entity Spawn (0x14) ===
+
Advancement display:
  
'''Server to Client only'''
+
{| class="wikitable"
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| Title
 +
| Chat
 +
|
 +
|-
 +
| Description
 +
| Chat
 +
|
 +
|-
 +
| Icon
 +
| [[Slot]]
 +
|
 +
|-
 +
| Frame type
 +
| VarInt enum
 +
| 0 = <code>task</code>, 1 = <code>challenge</code>, 2 = <code>goal</code>
 +
|-
 +
| Flags
 +
| Integer
 +
| 0x1: has background texture; 0x2: <code>show_toast</code>; 0x4: <code>hidden</code>
 +
|-
 +
| Background texture
 +
| Optional Identifier
 +
| Background texture location.  Only if flags indicates it.
 +
|-
 +
| X coord
 +
| Float
 +
|
 +
|-
 +
| Y coord
 +
| Float
 +
|
 +
|}
  
The only named entities (at the moment) are players (either real or NPC/Bot). This packet is sent by the server when a player comes into visible range, '''not''' when a player joins.
+
Advancement progress:
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
!colspan="2"| Field Name
! class="col0 centeralign" | Packet ID
+
!colspan="2"| Field Type
! class="col1 rightalign" | Field Name
+
! Notes
! class="col2" | Field Type
+
|-
! class="col3" | Example
+
|colspan="2"| Size
! class="col4" | Notes
+
|colspan="2"| VarInt
|- class="row1"
+
| Size of the following array
| class="col0 centeralign" rowspan="8" | 0x14
+
|-
| class="col1" | EID
+
|rowspan="2"| Criteria
| class="col2" | int
+
| Criterion identifier
| class="col3" | <code>94453</code>
+
|rowspan="2"| Array
| class="col4" | Player ID
+
| Identifier
|- class="row2"
+
| The identifier of the criterion.
| class="col0" | Player Name
+
|-
| class="col1" | string
+
| Criterion progress
| class="col2" | <code>Twdtwd</code>
+
| Criterion progress
| class="col3" |
+
|
|- class="row3"
+
|}
| class="col0" | X
+
 
| class="col1" | int
+
Criterion progress:
| class="col2" | <code>784</code>
 
| class="col3" | Player X as Absolute Integer
 
|- class="row4"
 
| class="col0" | Y
 
| class="col1" | int
 
| class="col2" | <code>2131</code>
 
| class="col3" | Player Y as Absolute Integer
 
|- class="row5"
 
| class="col0" | Z
 
| class="col1" | int
 
| class="col2" | <code>-752</code>
 
| class="col3" | Player Z as Absolute Integer
 
|- class="row6"
 
| class="col0" | Rotation
 
| class="col1" | byte
 
| class="col2" | <code>0</code>
 
| class="col3" | Player rotation as a packed byte
 
|- class="row7"
 
| class="col0" | Pitch
 
| class="col1" | byte
 
| class="col2" | <code>0</code>
 
| class="col3" | Player rotation as a packed byte
 
|- class="row8"
 
| class="col0" | Current Item
 
| class="col1" | short
 
| class="col2" | <code>0</code>
 
| class="col3" | The item the player is currently holding
 
|- class="row9"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 23 bytes + length of strings
 
|}
 
  
=== Pickup Spawn (0x15) ===
+
{| class="wikitable"
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| Achieved
 +
| Boolean
 +
| If true, next field is present
 +
|-
 +
| Date of achieving
 +
| Optional Long
 +
| As returned by [https://docs.oracle.com/javase/6/docs/api/java/util/Date.html#getTime() <code>Date.getTime</code>]
 +
|}
  
A pickup spawn is sent by the server whenever an item on the ground (say a pickaxe thrown on the ground) comes into range of the player. It used to be sent by the client when an item is dropped from a tile (chest or furnace) or from inventory, but that is now done with the new packets for server-side inventory (see [[#Window click (0x66)|0x66]]).
+
==== Entity Properties ====
  
It is completely acceptable for servers to ignore the EID issued by the client in this packet and instead create a new packet with a server-controlled EID when sending this packet out to clients.
+
Sets {{Minecraft Wiki|Attribute|attributes}} on the given entity.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0 centeralign" | Packet ID
+
! State
! class="col1 rightalign" | Field Name
+
! Bound To
! class="col2" | Field Type
+
!colspan="2"| Field Name
! class="col3" | Example
+
!colspan="2"| Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="10" | 0x15
+
|rowspan="6"| 0x59
| class="col1" | EID
+
|rowspan="6"| Play
| class="col2" | int
+
|rowspan="6"| Client
| class="col3" | <code>157617</code>
+
|colspan="2"| Entity ID
| class="col4" | Unique entity ID
+
|colspan="2"| VarInt
|- class="row2"
+
|  
| class="col0" | Item
+
|-
| class="col1" | short
+
|colspan="2"| Number Of Properties
| class="col2" | <code>4</code>
+
|colspan="2"| Int
| class="col3" | The item ID
+
| Number of elements in the following array
|- class="row3"
+
|-
| class="col0" | Count
+
|rowspan="4"| Property
| class="col1" | byte
+
| Key
| class="col2" | <code>1</code>
+
|rowspan="4"| Array
| class="col3" | The number of items
+
| String (64)
|- class="row4"
+
| See below
| class="col0" | Damage/Data
+
|-
| class="col1" | short
+
| Value
| class="col2" |  
+
| Double
| class="col3" | New field in beta 1.2 update (see below)
+
| See below
|- class="row5"
+
|-
| class="col0" | X
+
| Number Of Modifiers
| class="col1" | int
+
| VarInt
| class="col2" | <code>133</code>
+
| Number of elements in the following array
| class="col3" | Item X as Absolute Integer
+
|-
|- class="row6"
+
| Modifiers
| class="col0" | Y
+
| Array of Modifier Data
| class="col1" | int
+
| See {{Minecraft Wiki|Attribute#Modifiers}}. Modifier Data defined below.
| class="col2" | <code>913</code>
+
|}
| class="col3" | Item Y as Absolute Integer
 
|- class="row7"
 
| class="col0" | Z
 
| class="col1" | int
 
| class="col2" | <code>63552</code>
 
| class="col3" | Item Z as Absolute Integer
 
|- class="row8"
 
| class="col0" | Rotation
 
| class="col1" | byte
 
| class="col2" | <code>252</code>
 
| class="col3" | Item rotation as a packed byte
 
|- class="row9"
 
| class="col0" | Pitch
 
| class="col1" | byte
 
| class="col2" | <code>25</code>
 
| class="col3" | Item pitch as a packed byte
 
|- class="row10"
 
| class="col0" | Roll
 
| class="col1" | byte
 
| class="col2" | <code>12</code>
 
| class="col3" | Item roll as a packed byte
 
|- class="row11"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 25 bytes
 
|}
 
'''"Damage" field'''
 
This field is also used to store item metadata. E.g. you mined birch wood(its id is the same as normal wood) so you must set damage to the metadata of birch wood(2). The same case is wool. Id is the same but data is different.For example: you mined blue wool so your damage field should send value 0xB.
 
  
=== Collect Item (0x16) ===
+
Known Key values (see also {{Minecraft Wiki|Attribute#Modifiers}}):
  
'''Server to Client only'''
+
{| class="wikitable"
 +
|-
 +
! Key
 +
! Default
 +
! Min
 +
! Max
 +
! Label
 +
|-
 +
| generic.maxHealth
 +
| 20.0
 +
| 0.0
 +
| 1024.0
 +
| Max Health
 +
|-
 +
| generic.followRange
 +
| 32.0
 +
| 0.0
 +
| 2048.0
 +
| Follow Range
 +
|-
 +
| generic.knockbackResistance
 +
| 0.0
 +
| 0.0
 +
| 1.0
 +
| Knockback Resistance
 +
|-
 +
| generic.movementSpeed
 +
| 0.7
 +
| 0.0
 +
| 1024.0
 +
| Movement Speed
 +
|-
 +
| generic.attackDamage
 +
| 2.0
 +
| 0.0
 +
| 2048.0
 +
| Attack Damage
 +
|-
 +
| generic.attackSpeed
 +
| 4.0
 +
| 0.0
 +
| 1024.0
 +
| Attack Speed
 +
|-
 +
| generic.flyingSpeed
 +
| 0.4
 +
| 0.0
 +
| 1024.0
 +
| Flying Speed
 +
|-
 +
| generic.armor
 +
| 0.0
 +
| 0.0
 +
| 30.0
 +
| Armor
 +
|-
 +
| generic.armorToughness
 +
| 0.0
 +
| 0.0
 +
| 20.0
 +
| Armor Toughness
 +
|-
 +
| generic.attackKnockback
 +
| 0.0
 +
| 0.0
 +
| 5.0
 +
| &mdash;
 +
|-
 +
| generic.luck
 +
| 0.0
 +
| -1024.0
 +
| 1024.0
 +
| Luck
 +
|-
 +
| horse.jumpStrength
 +
| 0.7
 +
| 0.0
 +
| 2.0
 +
| Jump Strength
 +
|-
 +
| zombie.spawnReinforcements
 +
| 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)
 +
|}
  
Sent by the server when someone picks up an item lying on the ground - its sole purpose appears to be the animation of the item flying towards you. It doesn't destroy the entity in the client memory ([[#Destroy_Entity_.280x1D.29|0x1D]] does that), and it doesn't add it to your inventory ([[#Window_items_.280x68.29|0x67]] does that).
+
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.
  
 +
''Modifier Data'' structure:
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
|-
! class="col0" | Packet ID
+
! Field Name
! class="col1" | Field Name
+
! Field Type
! class="col2" | Field Type
+
! Notes
! class="col3" | Example
+
|-
! class="col4" | Notes
+
| UUID
|- class="row1"
+
| UUID
| class="col0 centeralign" rowspan="2" | 0x16
+
|  
| class="col1 centeralign" | Collected EID
+
|-
| class="col2 centeralign" | int
+
| Amount
| class="col3 centeralign" | <code>38</code>
+
| Double
| class="col4 leftalign" |
+
| May be positive or negative
|- class="row2"
+
|-
| class="col0 centeralign" | Collector EID
+
| Operation
| class="col1 centeralign" | int
+
| Byte
| class="col2 centeralign" | <code>20</code>
+
| See below
| class="col3 leftalign" |
+
|}
|- class="row3"
+
 
! class="col0" | Total Size:
+
The operation controls how the base value of the modifier is changed.
| class="col1 rightalign" colspan="4" | 9 bytes
 
|}
 
  
=== Add Object/Vehicle (0x17) ===
+
* 0: Add/subtract amount
 +
* 1: Add/subtract amount percent of the current value
 +
* 2: Multiply by amount percent
  
'''Server to Client only'''
+
All of the 0's are applied first, and then the 1's, and then the 2's.
  
Sent by the server when an Object/Vehicle is created.
+
==== Entity Effect ====
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="5" | 0x17
+
|rowspan="5"| 0x5A
| class="col1 centeralign" | EID
+
|rowspan="5"| Play
| class="col2 centeralign" | int
+
|rowspan="5"| Client
| class="col3 centeralign" | <code>62</code>
+
| Entity ID
| class="col4" | Entity ID of the Object
+
| VarInt
|- class="row2"
+
|  
| class="col0 centeralign" | Type
+
|-
| class="col1 centeralign" | byte
+
| Effect ID
| class="col2 centeralign" | <code>11</code>
+
| Byte
| class="col3" | The type of object (see below)
+
| See {{Minecraft Wiki|Status effect#List of effects|this table}}
|- class="row3"
+
|-
| class="col0 centeralign" | X
+
| Amplifier
| class="col1 centeralign" | int
+
| Byte
| class="col2 centeralign" | <code>16080</code>
+
| Notchian client displays effect level as Amplifier + 1
| class="col3" | The Absolute Integer X Position of the object
+
|-
|- class="row4"
+
| Duration
| class="col0 centeralign" | Y
+
| VarInt
| class="col1 centeralign" | int
+
| Duration in ticks.
| class="col2 centeralign" | <code>2299</code>
+
|-
| class="col3" | The Absolute Integer Y Position of the object
+
| Flags
|- class="row5"
+
| Byte
| class="col0 centeralign" | Z
+
| Bit field, see below.
| class="col1 centeralign" | int
+
|}
| class="col2 centeralign" | <code>592</code>
+
 
| class="col3" | The Absolute Integer Z Position of the object
+
Within flags:
|- class="row6"
+
 
! class="col0" | Total Size:
+
* 0x01: Is ambient - was the effect spawned from a beacon?  All beacon-generated effects are ambient.  Ambient effects use a different icon in the HUD (blue border rather than gray).  If all effects on an entity are ambient, the [[Entities#Living|"Is potion effect ambient" living metadata field]] should be set to true.  Usually should not be enabled.
| class="col1 rightalign" colspan="4" | 18 bytes
+
* 0x02: Show particles - should all particles from this effect be hidden?  Effects with particles hidden are not included in the calculation of the effect color, and are not rendered on the HUD (but are still rendered within the inventory).  Usually should be enabled.
|}
+
* 0x04: Show icon - should the icon be displayed on the client?  Usually should be enabled.
  
Object Types
+
==== Declare Recipes ====
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Type ID
+
! State
! class="col1" | Type Name
+
! Bound To
|- class="row1"
+
!colspan="2"| Field Name
| class="col0" | 1
+
!colspan="2"| Field Type
| class="col1" | Boats
+
! Notes
|- class="row2"
+
|-
| class="col0" | 10
+
|rowspan="4"| 0x5B
| class="col1" | Minecart
+
|rowspan="4"| Play
|- class="row3"
+
|rowspan="4"| Client
| class="col0" | 11
+
|colspan="2"| Num Recipes
| class="col1" | Storage Cart
+
|colspan="2"| VarInt
|- class="row4"
+
| Number of elements in the following array
| class="col0" | 12
+
|-
| class="col1" | Powered Cart
+
|rowspan="3"| Recipe
|- class="row5"
+
| Recipe ID
| class="col0" | 50
+
|rowspan="3"| Array
| class="col1" | Activated TNT
+
| Identifier
|- class="row6"
+
|
| class="col0" | 60
+
|-
| class="col1" | Arrow <!-- Player- and skeleton- fired arrows.-->
+
| Type
|- class="row7"
+
| String
| class="col0" | 61
+
| The recipe type, see below
| class="col1" | Thrown Snowball
+
|-
|- class="row8"
+
| Data
| class="col0" | 62
+
| Optional, varies
| class="col1" | Thrown Egg
+
| Additional data for the recipe.  For some types, there will be no data.
|- class="row9"
+
|}
| class="col0" | 70
 
| class="col1" | Falling Sand
 
|- class="row10"
 
| class="col0" | 71
 
| class="col1" | Falling Gravel
 
|- class="row11"
 
| class="col0" | 90
 
| class="col1" | Fishing Float
 
|}
 
  
=== Mob Spawn (0x18) ===
+
Recipe types:
  
'''Server to Client only'''
+
{| class="wikitable"
 +
! Type
 +
! Description
 +
! Data
 +
|-
 +
| <code>crafting_shapeless</code>
 +
| Shapeless crafting recipe.  All items in the ingredient list must be present, but in any order/slot.
 +
| As follows:
 +
  {| class="wikitable"
 +
    ! 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]]
 +
    |
 +
    |}
 +
|-
 +
| <code>crafting_shaped</code>
 +
| Shaped crafting recipe.  All items must be present in the same pattern (which may be flipped horizontally or translated)
 +
| As follows:
 +
  {| class="wikitable"
 +
    ! 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]]
 +
    |
 +
    |}
 +
|-
 +
| <code>crafting_special_armordye</code>
 +
| Recipe for dying leather armor
 +
|rowspan="13"| None
 +
|-
 +
| <code>crafting_special_bookcloning</code>
 +
| Recipe for copying contents of written books
 +
|-
 +
| <code>crafting_special_mapcloning</code>
 +
| Recipe for copying maps
 +
|-
 +
| <code>crafting_special_mapextending</code>
 +
| Recipe for adding paper to maps
 +
|-
 +
| <code>crafting_special_firework_rocket</code>
 +
| Recipe for making firework rockets
 +
|-
 +
| <code>crafting_special_firework_star</code>
 +
| Recipe for making firework stars
 +
|-
 +
| <code>crafting_special_firework_star_fade</code>
 +
| Recipe for making firework stars fade between multiple colors
 +
|-
 +
| <code>crafting_special_repairitem</code>
 +
| Recipe for repairing items via crafting
 +
|-
 +
| <code>crafting_special_tippedarrow</code>
 +
| Recipe for crafting tipped arrows
 +
|-
 +
| <code>crafting_special_bannerduplicate</code>
 +
| Recipe for copying banner patterns
 +
|-
 +
| <code>crafting_special_banneraddpattern</code>
 +
| Recipe for adding patterns to banners
 +
|-
 +
| <code>crafting_special_shielddecoration</code>
 +
| Recipe for applying a banner's pattern to a shield
 +
|-
 +
| <code>crafting_special_shulkerboxcoloring</code>
 +
| Recipe for recoloring a shulker box
 +
|-
 +
| <code>smelting</code>
 +
| Smelting recipe
 +
|rowspan="4"| As follows:
 +
  {| class="wikitable"
 +
    ! Name
 +
    ! Type
 +
    ! Description
 +
    |-
 +
    | Group
 +
    | String
 +
    | Used to group similar recipes together in the recipe book.
 +
    |-
 +
    | Ingredient
 +
    | Ingredient
 +
    |
 +
    |-
 +
    | Result
 +
    | [[Slot]]
 +
    |
 +
    |-
 +
    | Experience
 +
    | Float
 +
    |
 +
    |-
 +
    | Cooking time
 +
    | VarInt
 +
    |
 +
    |}
 +
|-
 +
| <code>blasting</code>
 +
| Blast furnace recipe
 +
|-
 +
| <code>smoking</code>
 +
| Smoker recipe
 +
|-
 +
| <code>campfire_cooking</code>
 +
| Campfire recipe
 +
|-
 +
| <code>stonecutting</code>
 +
| Stonecutter recipe
 +
| As follows:
 +
  {| class="wikitable"
 +
    ! Name
 +
    ! Type
 +
    ! Description
 +
    |-
 +
    | Group
 +
    | String
 +
    | Used to group similar recipes together in the recipe book.  Tag is present in recipe JSON.
 +
    |-
 +
    | Ingredient
 +
    | Ingredient
 +
    |
 +
    |-
 +
    | Result
 +
    | [[Slot]]
 +
    |
 +
    |}
 +
|}
  
Sent by the server when a Mob Entity is Spawned
+
Ingredient is defined as:
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Name
! class="col0" | Packet ID
+
! Type
! class="col1" | Field Name
+
! Description
! class="col2" | Field Type
+
|-
! class="col3" | Example
+
| Count
! class="col4" | Notes
+
| VarInt
|- class="row1"
+
| Number of elements in the following array
| class="col0 centeralign" rowspan="8" | 0x18
+
|-
| class="col1 centeralign" | EID
+
| Items
| class="col2 centeralign" | int
+
| Array of [[Slot]]
| class="col3 centeralign" | <code>446</code>
+
| Any item in this array may be used for the recipe.  The count of each item should be 1.
| class="col4" | Entity ID
+
|}
|- class="row2"
 
| class="col0 centeralign" | Type
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>91</code>
 
| class="col3" | The type of Mob Entity Type
 
|- class="row3"
 
| class="col0 centeralign" | X
 
| class="col1 centeralign" | int
 
| class="col2 centeralign" | <code>13366</code>
 
| class="col3" | The Absolute Integer X Position of the object
 
|- class="row4"
 
| class="col0 centeralign" | Y
 
| class="col1 centeralign" | int
 
| class="col2 centeralign" | <code>2176</code>
 
| class="col3" | The Absolute Integer Y Position of the object
 
|- class="row5"
 
| class="col0 centeralign" | Z
 
| class="col1 centeralign" | int
 
| class="col2 centeralign" | <code>1680</code>
 
| class="col3" | The Absolute Integer Z Position of the object
 
|- class="row6"
 
| class="col0 centeralign" | Yaw
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>-27</code>
 
| class="col3" | The X Axis rotation as a fraction of 360
 
|- class="row7"
 
| class="col0 centeralign" | Pitch
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>0</code>
 
| class="col3" | The Y Axis rotation as a fraction of 360
 
|- class="row8"
 
| class="col0 centeralign" | Data Stream
 
| class="col1 centeralign" | Metadata
 
| class="col2 centeralign" | <code>127</code>
 
| class="col3" | Indexed metadata for Mob (STILL DECODING!). Terminated by 0x7F.
 
|- class="row9"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 20 bytes + Metadata (at least 1)
 
|}
 
  
Metadata index 0 is a byte representing a set of 8 boolean flags:
+
==== Tags ====
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Bit index
+
! State
! class="col1" | Bit mask
+
! Bound To
! class="col2" | Meaning
+
! Field Name
|- class="row1"
+
! Field Type
| class="col0" | 0
+
! Notes
| class="col1" | 0x01
+
|-
| class="col2" | Entity on fire
+
|rowspan="4"| 0x5C
|- class="row2"
+
|rowspan="4"| Play
| class="col0" | 1
+
|rowspan="4"| Client
| class="col1" | 0x02
+
| Block Tags
| class="col2" | Entity crouched
+
| (See below)
|- class="row3"
+
| IDs are block IDs
| class="col0" | 2
+
|-
| class="col1" | 0x04
+
| Item Tags
| class="col2" | Entity riding
+
| (See below)
|}
+
| IDs are item IDs
 +
|-
 +
| Fluid Tags
 +
| (See below)
 +
| IDs are fluid IDs
 +
|-
 +
| Entity Tags
 +
| (See below)
 +
| IDs are entity IDs
 +
|}
  
Mob Types (Incomplete)
+
Tags look like:
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
!colspan="2"| Field Name
! class="col0" | Type ID
+
!colspan="2"| Field Type
! class="col1" | Type Name
+
! Notes
! class="col2" | Metadata
+
|-
|- class="row1"
+
|colspan="2"| Length
| class="col0" | 50
+
|colspan="2"| VarInt
| class="col1" | Creeper
+
| Number of elements in the following array
| class="col2" | Index 16. Byte. possible values: -1, 1
+
|-
|- class="row2"
+
|rowspan="3"| Tags
| class="col0" | 51
+
| Tag name
| class="col1" | Skeleton
+
|rowspan="3"| Array
| class="col2" |  
+
| Identifier
|- class="row3"
+
|
| class="col0" | 52
+
|-
| class="col1" | Spider
+
| Count
| class="col2" |  
+
| VarInt
|- class="row4"
+
| Number of elements in the following array
| class="col0" | 53
+
|-
| class="col1" | Giant Zombie
+
| Entries
| class="col2" |
+
| Array of VarInt
|- class="row5"
+
| Numeric ID of the block/item.
| class="col0" | 54
+
|}
| class="col1" | Zombie
+
 
| class="col2" |
+
=== Serverbound ===
|- class="row6"
+
 
| class="col0" | 55
+
==== Teleport Confirm ====
| class="col1" | Slime (random size?)
 
| class="col2" |
 
|- class="row7"
 
| class="col0" | 56
 
| class="col1" | Ghast
 
| class="col2" |
 
|- class="row8"
 
| class="col0" | 57
 
| class="col1" | Zombie Pigman
 
| class="col2" |
 
|- class="row9"
 
| class="col0" | 90
 
| class="col1" | Pig
 
| class="col2" | Index 16. Byte. Possible values: 0, 1
 
|- class="row10"
 
| class="col0" | 91
 
| class="col1" | Sheep
 
| class="col2" | Index 16. Byte. Bit 0x10 indicates shearedness, the lower 4 bits indicate wool color.
 
|- class="row11"
 
| class="col0" | 92
 
| class="col1" | Cow
 
| class="col2" |
 
|- class="row12"
 
| class="col0" | 93
 
| class="col1" | Hen
 
| class="col2" |
 
|- class="row13"
 
| class="col0" | 94
 
| class="col1" | Squid
 
| class="col2" |
 
|}
 
  
Sheep Wool Colors
+
Sent by client as confirmation of [[#Player Position And Look (clientbound)|Player Position And Look]].
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Index
+
! State
! class="col1" | Wool Color
+
! Bound To
|- class="row1"
+
! Field Name
| class="col0" | 0
+
! Field Type
| class="col1" | White
+
! Notes
|- class="row2"
+
|-
| class="col0" | 1
+
| 0x00
| class="col1" | Orange
+
| Play
|- class="row3"
+
| Server
| class="col0" | 2
+
| Teleport ID
| class="col1" | Magenta
+
| VarInt
|- class="row4"
+
| The ID given by the [[#Player Position And Look (clientbound)|Player Position And Look]] packet
| class="col0" | 3
+
|}
| class="col1" | LightBlue
 
|- class="row5"
 
| class="col0" | 4
 
| class="col1" | Yellow
 
|- class="row6"
 
| class="col0" | 5
 
| class="col1" | Lime
 
|- class="row7"
 
| class="col0" | 6
 
| class="col1" | Pink
 
|- class="row8"
 
| class="col0" | 7
 
| class="col1" | Gray
 
|- class="row9"
 
| class="col0" | 8
 
| class="col1" | Silver
 
|- class="row10"
 
| class="col0" | 9
 
| class="col1" | Cyan
 
|- class="row11"
 
| class="col0" | 10
 
| class="col1" | Purple
 
|- class="row12"
 
| class="col0" | 11
 
| class="col1" | Blue
 
|- class="row13"
 
| class="col0" | 12
 
| class="col1" | Brown
 
|- class="row14"
 
| class="col0" | 13
 
| class="col1" | Green
 
|- class="row15"
 
| class="col0" | 14
 
| class="col1" | Red
 
|- class="row16"
 
| class="col0" | 15
 
| class="col1" | Black
 
|}
 
  
=== Entity: Painting (0x19) ===
+
==== Query Block NBT ====
  
This packet shows location, name, and type of painting.
+
Used when <kbd>Shift</kbd>+<kbd>F3</kbd>+<kbd>I</kbd> is pressed while looking at a block.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x01
 +
|rowspan="2"| Play
 +
|rowspan="2"| Server
 +
| Transaction ID
 +
| VarInt
 +
| An incremental ID so that the client can verify that the response matches.
 +
|-
 +
| Location
 +
| Position
 +
| The location of the block to check.
 +
|}
 +
 
 +
==== Set Difficulty ====
 +
 
 +
Must have at least op level 2 to use.  Appears to only be used on singleplayer; the difficulty buttons are still disabled in multiplayer.
  
TODO: Verify "Type" field and coordinate type.
 
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="6" | 0x19
+
|rowspan="1"| 0x02
| class="col1 centeralign" | Entity ID
+
|rowspan="1"| Play
| class="col2 centeralign" | int
+
|rowspan="1"| Server
| class="col3 centeralign" | <code>0x00000326</code>
+
| New difficulty
| class="col4 centeralign" | Unique entity ID
+
| Byte
|- class="row2"
+
| 0: peaceful, 1: easy, 2: normal, 3: hard
| class="col1 centeralign" | Title
+
|}
| class="col2 centeralign" | String
+
 
| class="col3 centeralign" | <code>Creepers</code>
+
==== Chat Message (serverbound) ====
| class="col4 centeralign" | Name of the painting
 
|- class="row3"
 
| class="col1 centeralign" | X
 
| class="col2 centeralign" | int
 
| class="col3 centeralign" | <code>50</code>
 
| class="col4 centeralign" | Block? coordinate
 
|- class="row4"
 
| class="col1 centeralign" | Y
 
| class="col2 centeralign" | int
 
| class="col3 centeralign" | <code>66</code>
 
| class="col4 centeralign" | Block? coordinate
 
|- class="row5"
 
| class="col1 centeralign" | Z
 
| class="col2 centeralign" | int
 
| class="col3 centeralign" | <code>-50</code>
 
| class="col4 centeralign" | Block? coordinate
 
|- class="row6"
 
| class="col1 centeralign" | Type
 
| class="col2 centeralign" | int
 
| class="col3 centeralign" | <code>0</code>
 
| class="col4 centeralign" | (?) Indicate which graphic to use
 
|}
 
  
=== Entity Velocity? (0x1C) ===
+
Used to send a chat message to the server.  The message may not be longer than 256 characters or else the server will kick the client.
This packet is new to version 4 of the protocol, and is believed to be Entity Velocity/Motion.
 
  
Velocity is believed to be in units of 1/32000 of a block per server tick (200ms);
+
If the message starts with a <code>/</code>, the server will attempt to interpret it as a command.  Otherwise, the server will broadcast the same chat message to all players on the server (including the player that sent the message), prepended with player's name.  Specifically, it will respond with a translate [[chat]] component, "<code>chat.type.text</code>" with the first parameter set to the display name of the player (including some chat component logic to support clicking the name to send a PM) and the second parameter set to the message. See [[Chat#Processing chat|processing chat]] for more information.
for example, -1343 would move (-1343 / 32000) = -0.04196875 blocks per tick (or -0.20984375 blocks per second).
 
  
Each axis' velocity is capped between -0.9 and 0.9 blocks per tick (packet values -28800 to 28800).
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="1"| 0x03
 +
|rowspan="1"| Play
 +
|rowspan="1"| Server
 +
| Message
 +
| String (256)
 +
| The client sends the raw input, not a [[Chat]] component
 +
|}
  
(This packet data values are not fully verified)
+
==== Client Status ====
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="4" | 0x1C
+
|rowspan="1"| 0x04
| class="col1 centeralign" | Entity ID
+
|rowspan="1"| Play
| class="col2 centeralign" | int
+
|rowspan="1"| Server
| class="col3 centeralign" | <code>1805</code>
+
| Action ID
| class="col4" |
+
| VarInt Enum
The entity ID
+
| See below
|- class="row2"
+
|}
| class="col0 centeralign" | Velocity X
+
 
| class="col1 centeralign" | short
+
''Action ID'' values:
| class="col2 centeralign" | <code>-1343</code>
 
| class="col3" |
 
Velocity on the X axis
 
|- class="row3"
 
| class="col0 centeralign" | Velocity Y
 
| class="col1 centeralign" | short
 
| class="col2 centeralign" | <code>0</code>
 
| class="col3" |
 
Velocity on the Y axis
 
|- class="row4"
 
| class="col0 centeralign" | Velocity Z
 
| class="col1 centeralign" | short
 
| class="col2 centeralign" | <code>0</code>
 
| class="col3" |
 
Velocity on the Z axis
 
|- class="row5"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 11 bytes
 
|}
 
  
=== Destroy Entity (0x1D) ===
+
{| class="wikitable"
 +
|-
 +
! Action ID
 +
! Action
 +
! Notes
 +
|-
 +
| 0
 +
| Perform respawn
 +
| Sent when the client is ready to complete login and when the client is ready to respawn after death.
 +
|-
 +
| 1
 +
| Request stats
 +
| Sent when the client opens the Statistics menu
 +
|}
  
'''Server to Client only'''
+
==== Client Settings ====
  
Sent by the server when an Entity is to be destroyed on the client.
+
Sent when the player connects, or when settings are changed.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" | 0x1D
+
|rowspan="6"| 0x05
| class="col1 centeralign" | EID
+
|rowspan="6"| Play
| class="col2 centeralign" | int
+
|rowspan="6"| Server
| class="col3 centeralign" | <code>446</code>
+
| Locale
| class="col4 centeralign" | Entity ID
+
| String (16)
|- class="row2"
+
| e.g. en_GB
! class="col0" | Total Size:
+
|-
| class="col1 rightalign" colspan="4" | 5 bytes
+
| View Distance
|}
+
| Byte
 +
| Client-side render distance, in chunks
 +
|-
 +
| Chat Mode
 +
| VarInt Enum
 +
| 0: enabled, 1: commands only, 2: hidden.  See [[Chat#Processing chat|processing chat]] for more information.
 +
|-
 +
| Chat Colors
 +
| Boolean
 +
| “Colors” multiplayer setting
 +
|-
 +
| Displayed Skin Parts
 +
| Unsigned Byte
 +
| Bit mask, see below
 +
|-
 +
| Main Hand
 +
| VarInt Enum
 +
| 0: Left, 1: Right
 +
|}
 +
 
 +
''Displayed Skin Parts'' flags:
  
=== Entity (0x1E) ===
+
* Bit 0 (0x01): Cape enabled
 +
* Bit 1 (0x02): Jacket enabled
 +
* Bit 2 (0x04): Left Sleeve enabled
 +
* Bit 3 (0x08): Right Sleeve enabled
 +
* Bit 4 (0x10): Left Pants Leg enabled
 +
* Bit 5 (0x20): Right Pants Leg enabled
 +
* Bit 6 (0x40): Hat enabled
  
'''Server to Client only'''
+
The most significant bit (bit 7, 0x80) appears to be unused.
  
Most entity-related packets are subclasses of this packet. When sent from the server to the client, it may initialize the entry.
+
==== Tab-Complete (serverbound) ====
  
For player entities, either this packet or any move/look packet is sent several times per second.
+
Sent when the client needs to tab-complete a <code>minecraft:ask_server</code> suggestion type.
So the meaning of this packet is basically that the entity did not move/look since the last such packet.
 
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" | 0x1E
+
|rowspan="2"| 0x06
| class="col1 centeralign" | EID
+
|rowspan="2"| Play
| class="col2 centeralign" | int
+
|rowspan="2"| Server
| class="col3 centeralign" | <code>446</code>
+
| Transaction Id
| class="col4 centeralign" | Entity ID
+
| VarInt
|- class="row2"
+
| 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.
! class="col0" | Total Size:
+
|-
| class="col1 rightalign" colspan="4" | 5 bytes
+
| Text
|}
+
| String (32500)
 +
| All text behind the cursor without the <code>/</code> (e.g. to the left of the cursor in left-to-right languages like English)
 +
|}
  
=== Entity Relative Move (0x1F) ===
+
==== Window Confirmation (serverbound) ====
  
'''Server to Client only'''
+
If a confirmation sent by the client was not accepted, the server will reply with a [[#Window Confirmation (clientbound)|Window Confirmation (clientbound)]] packet with the Accepted field set to false. When this happens, the client must send this packet to apologize (as with movement), otherwise the server ignores any successive confirmations.
  
This packet is sent by the server when an entity moves less then 4 blocks; if an entity moves more then 4 blocks [[#Entity_Teleport_.280x22.29|Entity Teleport]] should be sent instead.
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="3"| 0x07
 +
|rowspan="3"| Play
 +
|rowspan="3"| Server
 +
| Window ID
 +
| Byte
 +
| The ID of the window that the action occurred in
 +
|-
 +
| Action Number
 +
| Short
 +
| Every action that is to be accepted has a unique number. This number is an incrementing integer (starting at 1) with separate counts for each window ID.
 +
|-
 +
| Accepted
 +
| Boolean
 +
| Whether the action was accepted
 +
|}
  
This packet allows at most four blocks movement in any direction, because byte range is from -128 to 127. Movement is an offset of Absolute Int; to convert relative move to block coordinate offset, divide by 32.
+
==== Click Window Button ====
  
 +
Used when clicking on window buttons.  Until 1.14, this was only used by enchantment tables.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="4" | 0x1F
+
|rowspan="2"| 0x08
| class="col1 centeralign" | EID
+
|rowspan="2"| Play
| class="col2 centeralign" | int
+
|rowspan="2"| Server
| class="col3 centeralign" | <code>459</code>
+
| Window ID
| class="col4" | Entity ID
+
| Byte
|- class="row2"
+
| The ID of the window sent by [[#Open Window|Open Window]]
| class="col0 centeralign" | dX
+
|-
| class="col1 centeralign" | byte
+
| Button ID
| class="col2 centeralign" | <code>1</code>
+
| Byte
| class="col3" | X axis Relative movement as an Absolute Integer
+
| Meaning depends on window type; see below
|- class="row3"
+
|}
| class="col0 centeralign" | dY
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>-7</code>
 
| class="col3" | Y axis Relative movement as an Absolute Integer
 
|- class="row4"
 
| class="col0 centeralign" | dZ
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>5</code>
 
| class="col3" | Z axis Relative movement as an Absolute Integer
 
|- class="row5"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 8 bytes
 
|}
 
  
=== Entity Look (0x20) ===
+
{| class="wikitable"
 +
! Window type
 +
! ID
 +
! Meaning
 +
|-
 +
|rowspan="3"| Enchantment Table
 +
| 0 || Topmost enchantment
 +
|-
 +
| 1 || Middle enchantment
 +
|-
 +
| 2 || Bottom enchantment
 +
|-
 +
|rowspan="4"| Lectern
 +
| 1 || Previous page (which does give a redstone output)
 +
|-
 +
| 2 || Next page
 +
|-
 +
| 3 || Take Book
 +
|-
 +
| 100+page || Opened page number - 100 + number
 +
|-
 +
| Stonecutter
 +
|colspan="2"| Recipe button number - 4*row + col.  Depends on the item.
 +
|-
 +
| Loom
 +
|colspan="2"| Recipe button number - 4*row + col.  Depends on the item.
 +
|}
  
'''Server to Client only'''
+
==== Click Window ====
  
This packet is sent by the server when an entity rotates.  Example: "Yaw" field 64 means a 90 degree turn.
+
This packet is sent by the player when it clicks on a slot in a window.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="3" | 0x20
+
|rowspan="6"| 0x09
| class="col1 centeralign" | EID
+
|rowspan="6"| Play
| class="col2 centeralign" | int
+
|rowspan="6"| Server
| class="col3 centeralign" | <code>459</code>
+
| Window ID
| class="col4" | Entity ID
+
| Unsigned Byte
|- class="row2"
+
| The ID of the window which was clicked. 0 for player inventory.
| class="col0 centeralign" | Yaw
+
|-
| class="col1 centeralign" | byte
+
| Slot
| class="col2 centeralign" | <code>126</code>
+
| Short
| class="col3" | The X Axis rotation as a fraction of 360
+
| The clicked slot number, see below
|- class="row3"
+
|-
| class="col0 centeralign" | Pitch
+
| Button
| class="col1 centeralign" | byte
+
| Byte
| class="col2 centeralign" | <code>0</code>
+
| The button used in the click, see below
| class="col3" | The Y Axis rotation as a fraction of 360
+
|-
|- class="row4"
+
| Action Number
! class="col0" | Total Size:
+
| Short
| class="col1 rightalign" colspan="4" | 7 bytes
+
| A unique number for the action, implemented by Notchian as a counter, starting at 1 (different counter for every window ID). Used by the server to send back a [[#Confirm Transaction (clientbound)|Confirm Transaction (clientbound)]].
|}
+
|-
 +
| Mode
 +
| VarInt Enum
 +
| Inventory operation mode, see below
 +
|-
 +
| Clicked item
 +
| [[Slot Data|Slot]]
 +
| The clicked slot. Has to be empty (item ID = -1) for drop mode.
 +
|}
  
=== Entity Look and Relative Move (0x21) ===
+
See [[Inventory]] for further information about how slots are indexed.
  
'''Server to Client only'''
+
When right-clicking on a stack of items, half the stack will be picked up and half left in the slot. If the stack is an odd number, the half left in the slot will be smaller of the amounts.
  
This packet is sent by the server when an entity rotates and moves.
+
The distinct type of click performed by the client is determined by the combination of the Mode and Button fields.
Since a byte range is limited from -128 to 127, and movement is offset of Absolute Int,
 
this packet allows at most four blocks movement in any direction. (-128/32 == -4)
 
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Mode
! class="col0" | Packet ID
+
! Button
! class="col1" | Field Name
+
! Slot
! class="col2" | Field Type
+
! Trigger
! class="col3" | Example
+
|-
! class="col4" | Notes
+
!rowspan="2"| 0
|- class="row1"
+
| 0
| class="col0 centeralign" rowspan="6" | 0x21
+
| Normal
| class="col1 centeralign" | EID
+
| Left mouse click
| class="col2 centeralign" | int
+
|-
| class="col3 centeralign" | <code>459</code>
+
| 1
| class="col4" | Entity ID
+
| Normal
|- class="row2"
+
| Right mouse click
| class="col0 centeralign" | dX
+
|-
| class="col1 centeralign" | byte
+
!rowspan="2"| 1
| class="col2 centeralign" | <code>1</code>
+
| 0
| class="col3" | X axis Relative movement as an Absolute Integer
+
| Normal
|- class="row3"
+
| Shift + left mouse click
| class="col0 centeralign" | dY
+
|-
| class="col1 centeralign" | byte
+
| 1
| class="col2 centeralign" | <code>-7</code>
+
| Normal
| class="col3" | Y axis Relative movement as an Absolute Integer
+
| Shift + right mouse click ''(identical behavior)''
|- class="row4"
+
|-
| class="col0 centeralign" | dZ
+
!rowspan="5"| 2
| class="col1 centeralign" | byte
+
| 0
| class="col2 centeralign" | <code>5</code>
+
| Normal
| class="col3" | Z axis Relative movement as an Absolute Integer
+
| Number key 1
|- class="row5"
+
|-
| class="col0 centeralign" | Yaw
+
| 1
| class="col1 centeralign" | byte
+
| Normal
| class="col2 centeralign" | <code>126</code>
+
| Number key 2
| class="col3" | The X Axis rotation as a fraction of 360
+
|-
|- class="row6"
+
| 2
| class="col0 centeralign" | Pitch
+
| Normal
| class="col1 centeralign" | byte
+
| Number key 3
| class="col2 centeralign" | <code>0</code>
+
|-
| class="col3" | The Y Axis rotation as a fraction of 360
+
| ⋮
|- class="row7"
+
|
! class="col0" | Total Size:
+
|
| class="col1 rightalign" colspan="4" | 10 bytes
+
|-
|}
+
| 8
 +
| Normal
 +
| Number key 9
 +
|-
 +
!rowspan="1"| 3
 +
| 2
 +
| Normal
 +
| Middle click, only defined for creative players in non-player inventories.
 +
|-
 +
!rowspan="4"| 4
 +
| 0
 +
| Normal*
 +
| Drop key (Q) (* Clicked item is different, see above)
 +
|-
 +
| 1
 +
| Normal*
 +
| Ctrl + Drop key (Ctrl-Q) ''(drops full stack)''
 +
|-
 +
| 0
 +
| -999
 +
| Left click outside inventory holding nothing ''(no-op)''
 +
|-
 +
| 1
 +
| -999
 +
| Right click outside inventory holding nothing ''(no-op)''
 +
|-
 +
!rowspan="9"| 5
 +
| 0
 +
| -999
 +
| Starting left mouse drag
 +
|-
 +
| 4
 +
| -999
 +
| Starting right mouse drag
 +
|-
 +
| 8
 +
| -999
 +
| Starting middle mouse drag, only defined for creative players in non-player inventories.  (Note: the vanilla client will still incorrectly send this for non-creative players - see [https://bugs.mojang.com/browse/MC-46584 MC-46584])
 +
|-
 +
| 1
 +
| Normal
 +
| Add slot for left-mouse drag
 +
|-
 +
| 5
 +
| Normal
 +
| Add slot for right-mouse drag
 +
|-
 +
| 9
 +
| Normal
 +
| Add slot for middle-mouse drag, only defined for creative players in non-player inventories.  (Note: the vanilla client will still incorrectly send this for non-creative players - see [https://bugs.mojang.com/browse/MC-46584 MC-46584])
 +
|-
 +
| 2
 +
| -999
 +
| Ending left mouse drag
 +
|-
 +
| 6
 +
| -999
 +
| Ending right mouse drag
 +
|-
 +
| 10
 +
| -999
 +
| Ending middle mouse drag, only defined for creative players in non-player inventories.  (Note: the vanilla client will still incorrectly send this for non-creative players - see [https://bugs.mojang.com/browse/MC-46584 MC-46584])
 +
|-
 +
! 6
 +
| 0
 +
| Normal
 +
| Double click
 +
|}
 +
 
 +
Starting from version 1.5, “painting mode” is available for use in inventory windows. It is done by picking up stack of something (more than 1 item), then holding mouse button (left, right or middle) and dragging held stack over empty (or same type in case of right button) slots. In that case client sends the following to server after mouse button release (omitting first pickup packet which is sent as usual):
 +
 
 +
# packet with mode 5, slot -999, button (0 for left | 4 for right);
 +
# packet for every slot painted on, mode is still 5, button (1 | 5);
 +
# packet with mode 5, slot -999, button (2 | 6);
 +
 
 +
If any of the painting packets other than the “progress” ones are sent out of order (for example, a start, some slots, then another start; or a left-click in the middle) the painting status will be reset.
 +
 
 +
The server will send back a [[#Confirm Transaction (clientbound)|Confirm Transaction]] packet. If the click was not accepted, the client must send a matching [[#Confirm Transaction (serverbound)|serverbound confirm transaction]] packet before sending more [[#Click Window|Click Window]] packets, otherwise the server will reject them silently. The Notchian server also sends a [[#Window Items|Window Items]] packet for the open window and [[#Set Slot|Set Slot]] packets for the clicked and cursor slot, but only when the click was not accepted, probably to resynchronize client and server.
  
=== Entity Teleport (0x22) ===
+
==== Close Window (serverbound) ====
  
'''Server to Client only'''
+
This packet is sent by the client when closing a window.
  
This packet is sent by the server when an entity moves more than 4 blocks.
+
Notchian clients send a Close Window packet with Window ID 0 to close their inventory even though there is never an [[#Open Window|Open Window]] packet for the inventory.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="6" | 0x22
+
| 0x0A
| class="col1 centeralign" | EID
+
| Play
| class="col2 centeralign" | int
+
| Server
| class="col3 centeralign" | <code>459</code>
+
| Window ID
| class="col4" | Entity ID
+
| Unsigned Byte
|- class="row2"
+
| This is the ID of the window that was closed. 0 for player inventory.
| class="col0 centeralign" | X
+
|}
| class="col1 centeralign" | int
+
 
| class="col2 centeralign" | <code>14162</code>
+
==== Plugin Message (serverbound) ====
| class="col3" | X axis position as an Absolute Integer
 
|- class="row3"
 
| class="col0 centeralign" | Y
 
| class="col1 centeralign" | int
 
| class="col2 centeralign" | <code>2176</code>
 
| class="col3" | Y axis position as an Absolute Integer
 
|- class="row4"
 
| class="col0 centeralign" | Z
 
| class="col1 centeralign" | int
 
| class="col2 centeralign" | <code>1111</code>
 
| class="col3" | Z axis position as an Absolute Integer
 
|- class="row5"
 
| class="col0 centeralign" | Yaw
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>126</code>
 
| class="col3" | The X Axis rotation as a fraction of 360
 
|- class="row6"
 
| class="col0 centeralign" | Pitch
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>0</code>
 
| class="col3" | The Y Axis rotation as a fraction of 360
 
|- class="row7"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 19 bytes
 
|}
 
  
=== Entity Status? (0x26) ===
+
{{Main|Plugin channels}}
  
'''Server to Client only'''
+
Mods and plugins can use this to send their data. Minecraft itself uses some [[plugin channel]]s. These internal channels are in the <code>minecraft</code> namespace.
  
[[File:Icon_exclaim.gif|:!:]] This command is not fully understood.
+
More documentation on this: [http://dinnerbone.com/blog/2012/01/13/minecraft-plugin-channels-messaging/ http://dinnerbone.com/blog/2012/01/13/minecraft-plugin-channels-messaging/]
  
This packet is new in version 6 of the protocol, and is believed to be indication of entity damage, death and explosion
+
Note that the length of Data is known only from the packet length, since the packet has no length field of any kind.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="3" | 0x26
+
|rowspan="2"| 0x0B
| class="col1 centeralign" | Entity ID
+
|rowspan="2"| Play
| class="col2 centeralign" | Int
+
|rowspan="2"| Server
| class="col3 centeralign" | 34353
+
| Channel
| class="col4" |
+
| Identifier
|- class="row3"
+
| Name of the [[plugin channel]] used to send the data
| class="col1 centeralign" | Entity Status?
+
|-
| class="col2 centeralign" | Byte
+
| Data
| class="col3 centeralign" | 0x03
+
| Byte Array
| class="col4" | Possible values: 2 (entity drowning?), 3 (entity dead?), 4, 5
+
| Any data, depending on the channel. <code>minecraft:</code> channels are documented [[plugin channel|here]].  The length of this array must be inferred from the packet length.
|- class="row4"
+
|}
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 6 bytes
 
|}
 
  
=== Attach Entity? (0x27) ===
+
==== Edit Book ====
This packet is new to version 4 of the protocol, and is believed to be Attach Entity.
 
  
This packet is sent when a player has been attached to an entity (e.g. Minecart)
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="3"| 0x0C
 +
|rowspan="3"| Play
 +
|rowspan="3"| Server
 +
| New book
 +
| [[Slot]]
 +
|
 +
|-
 +
| Is signing
 +
| Boolean
 +
| True if the player is signing the book; false if the player is saving a draft.
 +
|-
 +
| Hand
 +
| VarInt enum
 +
| 0: Main hand, 1: Off hand
 +
|}
  
(This packet data values are not fully verified)
+
When editing a draft, the [[NBT]] section of the Slot contains this:
 +
 
 +
<pre>
 +
TAG_Compound(<nowiki>''</nowiki>): 1 entry
 +
{
 +
  TAG_List('pages'): 2 entries
 +
  {
 +
    TAG_String(0): 'Something on Page 1'
 +
    TAG_String(1): 'Something on Page 2'
 +
  }
 +
}
 +
</pre>
 +
 
 +
When signing the book, it instead looks like this:
 +
 
 +
<pre>
 +
TAG_Compound(<nowiki>''</nowiki>): 3 entires
 +
{
 +
  TAG_String('author'): 'Steve'
 +
  TAG_String('title'): 'A Wonderful Book'
 +
  TAG_List('pages'): 2 entries
 +
  {
 +
    TAG_String(0): 'Something on Page 1'
 +
    TAG_String(1): 'Something on Page 2'
 +
  }
 +
}
 +
</pre>
 +
 
 +
==== Entity NBT Request ====
 +
 
 +
Used when <kbd>Shift</kbd>+<kbd>F3</kbd>+<kbd>I</kbd> is pressed while looking at an entity.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="2" | 0x27
+
|rowspan="2"| 0x0D
| class="col1 centeralign" | Entity ID
+
|rowspan="2"| Play
| class="col2 centeralign" | int
+
|rowspan="2"| Server
| class="col3 centeralign" | <code>1298</code>
+
| Transaction ID
| class="col4" |
+
| VarInt
The player entity ID being attached
+
| An incremental ID so that the client can verify that the response matches.
|- class="row2"
+
|-
| class="col0 centeralign" | Vehicle ID
+
| Entity ID
| class="col1 centeralign" | int
+
| VarInt
| class="col2 centeralign" | <code>1805</code>
+
| The ID of the entity to query.
| class="col3" |
+
|}
The vehicle entity ID attached to (-1 for unattaching)
+
 
|- class="row3"
+
==== Interact Entity ====
! class="col0" | Total Size:
+
 
| class="col1 rightalign" colspan="4" | 9 bytes
+
This packet is sent from the client to the server when the client attacks or right-clicks another entity (a player, minecart, etc).
|}
+
 
 +
A Notchian server only accepts this packet if the entity being attacked/used is visible without obstruction and within a 4-unit radius of the player's position.
 +
 
 +
Note that middle-click in creative mode is interpreted by the client and sent as a [[#Creative Inventory Action|Creative Inventory Action]] packet instead.
  
=== Entity Metadata (0x28) ===
 
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="2" | 0x28
+
|rowspan="6"| 0x0E
| class="col1 centeralign" | Entity ID
+
|rowspan="6"| Play
| class="col2 centeralign" | int
+
|rowspan="6"| Server
| class="col3 centeralign" | <code>0x00000326</code>
+
| Entity ID
| class="col4 centeralign" | Unique entity ID to update.
+
| VarInt
|- class="row2"
+
| The ID of the entity to interact
| class="col0 centeralign" | Entity Metadata
+
|-
| class="col1 centeralign" | Metadata
+
| Type
| class="col2 centeralign" | <code>0x00 0x01 0x7F</code>
+
| VarInt Enum
| class="col3 centeralign" | Metadata varies by mob... Needs type description
+
| 0: interact, 1: attack, 2: interact at
|- class="row3"
+
|-
! class="col0" | Total Size:
+
| Target X
| class="col1 rightalign" colspan="4" | 5 bytes + Metadata
+
| Optional Float
|}
+
| Only if Type is interact at
 +
|-
 +
| Target Y
 +
| Optional Float
 +
| Only if Type is interact at
 +
|-
 +
| Target Z
 +
| Optional Float
 +
| Only if Type is interact at
 +
|-
 +
| Hand
 +
| Optional VarInt Enum
 +
| Only if Type is interact or interact at; 0: main hand, 1: off hand
 +
|}
 +
 
 +
==== Keep Alive (serverbound) ====
  
=== Pre-Chunk (0x32) ===
+
The server will frequently send out a keep-alive, each containing a random ID. The client must respond with the same packet.
  
'''Server to Client only'''
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x0F
 +
| Play
 +
| Server
 +
| Keep Alive ID
 +
| Long
 +
|
 +
|}
  
This packet is sent by the server to notify the client to initialize (Mode=1) or unload (Mode=0) a chunk. The client is expected to allocate space for a full chunk (currently 16 x 128 x 16 blocks). One or more 0x33 packets will follow, specifying actual data to fill the chunk with.
+
==== Lock Difficulty ====
  
[[File:Icon_exclaim.gif|:!:]] Whenever you send this packet the client will clear any previous chunk at that spot if one has previously been sent. Clients don't like being in or next to an unloaded chunk, so try not to unload it if players are nearby. If the player appears to be twitching and stuck in place after joining the world, there is probably an unloaded chunk too close to them.
+
Must have at least op level 2 to use. Appears to only be used on singleplayer; the difficulty buttons are still disabled in multiplayer.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="3" | 0x32
+
|rowspan="1"| 0x10
| class="col1 centeralign" | X
+
|rowspan="1"| Play
| class="col2 centeralign" | int
+
|rowspan="1"| Server
| class="col3 centeralign" | <code>-9</code>
+
| Locked
| class="col4" | Chunk X Coordinate
+
| Boolean
|- class="row2"
+
|
| class="col0 centeralign" | Z
+
|}
| class="col1 centeralign" | int
+
 
| class="col2 centeralign" | <code>12</code>
+
==== Player Position ====
| class="col3" | Chunk Z Coordinate
+
 
|- class="row3"
+
Updates the player's XYZ position on the server.
| class="col0 centeralign" | Mode
 
| class="col1 centeralign" | bool
 
| class="col2 centeralign" | <code>1</code>
 
| class="col3" | If mode is 0 the client will unload the chunk, otherwise the client will initialize the chunk
 
|- class="row4"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 10 bytes
 
|}
 
  
=== Map Chunk (0x33) ===
+
Checking for moving too fast is achieved like this:
  
'''Server to Client only'''
+
* Each server tick, the player's current position is stored
 +
* When a player moves, the changes in x, y, and z coordinates are compared with the positions from the previous tick (&Delta;x, &Delta;y, &Delta;z)
 +
* Total movement distance squared is computed as &Delta;x&sup2; + &Delta;y&sup2; + &Delta;z&sup2;
 +
* The expected movement distance squared is computed as velocityX&sup2; + veloctyY&sup2; + velocityZ&sup2;
 +
* If the total movement distance squared value minus the expected movement distance squared value is more than 100 (300 if the player is using an elytra), they are moving too fast.
  
The client will overwrite all '''or part''' of a chunk using the region of data contained in this packet. The server specifies the region to write using a block position and size in X,Y,Z. Note that this region will always be inside a single chunk. (At least using the vanilla server. Unknown if the client has this limitation.)
+
If the player is moving too fast, it will be logged that "<player> moved too quickly! " followed by the change in x, y, and z, and the player will be teleported back to their current (before this packet) serverside position.
  
A server '''can''' send a 0x32 packet prior, allowing the client to initialize the chunk. However this doesn't always happen in practice. Thus the client should initialize the chunk on-demand.
+
Also, if the absolute value of X or the absolute value of Z is a value greater than 3.2×10<sup>7</sup>, or X, Y, or Z are not finite (either positive infinity, negative infinity, or NaN), the client will be kicked for “Invalid move player packet received”.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="8" | 0x33
+
|rowspan="4"| 0x11
| class="col1 centeralign" | X
+
|rowspan="4"| Play
| class="col2 centeralign" | int
+
|rowspan="4"| Server
| class="col3 centeralign" | <code>128</code>
+
| X
| class="col4" | Block X Coordinate
+
| Double
|- class="row2"
+
| Absolute position
| class="col0 centeralign" | Y
+
|-
| class="col1 centeralign" | short
+
| Feet Y
| class="col2 centeralign" | <code>0</code>
+
| Double
| class="col3" | Block Y Coordinate
+
| Absolute feet position, normally Head Y - 1.62
|- class="row3"
+
|-
| class="col0 centeralign" | Z
+
| Z
| class="col1 centeralign" | int
+
| Double
| class="col2 centeralign" | <code>-192</code>
+
| Absolute position
| class="col3" | Block Z Coordinate
+
|-
|- class="row4"
+
| On Ground
| class="col0 centeralign" | Size_X
+
| Boolean
| class="col1 centeralign" | byte
+
| True if the client is on the ground, false otherwise
| class="col2 centeralign" | <code>15</code>
+
|}
| class="col3" | Size_X is Actual X Size -1
 
|- class="row5"
 
| class="col0 centeralign" | Size_Y
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>127</code>
 
| class="col3" | Size_Y is Actual Y Size -1
 
|- class="row6"
 
| class="col0 centeralign" | Size_Z
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>15</code>
 
| class="col3" | Size_Z is Actual Z Size -1
 
|- class="row7"
 
| class="col0 centeralign" | Compressed size
 
| class="col1 centeralign" | int
 
| class="col2 centeralign" | <code>3663</code>
 
| class="col3" | Size of compressed region data
 
|- class="row8"
 
| class="col0 centeralign" | Compressed data
 
| class="col1 centeralign" | byte array
 
| class="col2 centeralign" | <code>…</code>
 
| class="col3" | The region data is compressed using ZLib Deflate function.
 
|- class="row9"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 18 bytes + Compressed chunk size
 
|}
 
  
=====X, Y, Z=====
+
==== Player Position And Rotation (serverbound) ====
This is the start position of the region, in '''world''' block coordinates.
 
  
To find which chunk is affected, in the same coordinates given by packet 0x32:
+
A combination of [[#Player Rotation|Player Rotation]] and [[#Player Position|Player Position]].
  ChunkX = X >> 4
 
  ChunkY = Y >> 7
 
  ChunkZ = Z >> 4
 
  
And conversely, which local block in the chunk to start at:
+
{| class="wikitable"
  StartX = X & 15
+
! Packet ID
  StartY = Y & 127 (not always 0!)
+
! State
  StartZ = Z & 15
+
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="6"| 0x12
 +
|rowspan="6"| Play
 +
|rowspan="6"| Server
 +
| X
 +
| Double
 +
| Absolute position
 +
|-
 +
| Feet Y
 +
| Double
 +
| Absolute feet position, normally Head Y - 1.62
 +
  |-
 +
| Z
 +
| Double
 +
| Absolute position
 +
|-
 +
| Yaw
 +
| Float
 +
| Absolute rotation on the X Axis, in degrees
 +
|-
 +
| Pitch
 +
| Float
 +
| Absolute rotation on the Y Axis, in degrees
 +
|-
 +
| On Ground
 +
| Boolean
 +
| True if the client is on the ground, false otherwise
 +
|}
  
=====SizeX, SizeY, SizeZ=====
+
==== Player Rotation ====
This is the size of the region, in blocks. The server will subtract one from the sizes and then cast them to a byte before sending. This is so that chunks as large as 256 are possible (the maximum size of a byte is 255; 256 - 1 = 255).
+
[[File:Minecraft-trig-yaw.png|thumb|The unit circle for yaw]]
 +
[[File:Yaw.png|thumb|The unit circle of yaw, redrawn]]
  
=====Compressed data=====
+
Updates the direction the player is looking in.
 +
 
 +
Yaw is measured in degrees, and does not follow classical trigonometry rules. The unit circle of yaw on the XZ-plane starts at (0, 1) and turns counterclockwise, with 90 at (-1, 0), 180 at (0,-1) and 270 at (1, 0). Additionally, yaw is not clamped to between 0 and 360 degrees; any number is valid, including negative numbers and numbers greater than 360.
 +
 
 +
Pitch is measured in degrees, where 0 is looking straight ahead, -90 is looking straight up, and 90 is looking straight down.
 +
 
 +
The yaw and pitch of player (in degrees), standing at point (x0, y0, z0) and looking towards point (x, y, z) can be calculated with:
 +
 
 +
dx = x-x0
 +
dy = y-y0
 +
dz = z-z0
 +
r = sqrt( dx*dx + dy*dy + dz*dz )
 +
yaw = -atan2(dx,dz)/PI*180
 +
if yaw < 0 then
 +
    yaw = 360 + yaw
 +
pitch = -arcsin(dy/r)/PI*180
 +
 
 +
You can get a unit vector from a given yaw/pitch via:
 +
 
 +
x = -cos(pitch) * sin(yaw)
 +
y = -sin(pitch)
 +
z = cos(pitch) * cos(yaw)
  
The data is compressed using the deflate() function in [http://www.zlib.net/ zlib]. After uncompressing, the data consists of four sequential sections, in order:
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="3"| 0x13
 +
|rowspan="3"| Play
 +
|rowspan="3"| Server
 +
| Yaw
 +
| Float
 +
| Absolute rotation on the X Axis, in degrees
 +
|-
 +
| Pitch
 +
| Float
 +
| Absolute rotation on the Y Axis, in degrees
 +
|-
 +
| On Ground
 +
| Boolean
 +
| True if the client is on the ground, False otherwise
 +
|}
  
* <div class="li"> Block type array (1 byte per block)</div>
+
==== Player Movement ====
* <div class="li"> Block metadata array (half byte/nibble per block)</div>
 
* <div class="li"> Block Light array (half byte/nibble per block)</div>
 
* <div class="li"> Sky Light array (half byte/nibble per block)</div>
 
  
The data is exactly <code>(Size_X+1) * (Size_Y+1) * (Size_Z+1) * 2.5</code> bytes long. Nibbles are not rounded either direction, which means that at least one dimension of the chunk must be even.
+
This packet as well as [[#Player Position|Player Position]], [[#Player Look|Player Look]], and [[#Player Position And Look 2|Player Position And Look]] are called the “serverbound movement packets”. Vanilla clients will send Player Position once every 20 ticks even for a stationary player.
  
The arrays are not interlaced.
+
This packet is used to indicate whether the player is on ground (walking/swimming), or airborne (jumping/falling).
  
In other words, there are Size_X number of '''x planes''', each plane made up of Size_Z number of '''z rows''', each row made up of Size_Y blocks indexed by y coordinate in order.
+
When dropping from sufficient height, fall damage is applied when this state goes from false to true. The amount of damage applied is based on the point where it last changed from true to false. Note that there are several movement related packets containing this state.
  
The block type array is indexed with:
+
{| class="wikitable"
  index = y + (z * (Size_Y+1)) + (x * (Size_Y+1) * (Size_Z+1))
+
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="1"| 0x14
 +
|rowspan="1"| Play
 +
|rowspan="1"| Server
 +
| On Ground
 +
| Boolean
 +
| True if the client is on the ground, false otherwise
 +
|}
  
The other arrays are similar but you need to divide the index by two after calculating the above. Then each byte contains data for '''two''' blocks. The low four bits contain the first (lower Y) nibble and the high four bits contain the second nibble.
+
==== Vehicle Move (serverbound) ====
  
If you have a FULL map chunk (Size_X = 15, Size_Y = 127, Size_Z = 15, you can calculate index coordinates:
+
Sent when a player moves in a vehicle. Fields are the same as in [[#Player Position And Look (serverbound)|Player Position And Look]]. Note that all fields use absolute positioning and do not allow for relative positioning.
  x = X + ( index >> 11 )
 
  y = index & 0x7F
 
  z = Z + ( (index & 0x780) >> 7 )
 
  
=== Multi Block Change (0x34) ===
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="5"| 0x15
 +
|rowspan="5"| Play
 +
|rowspan="5"| Server
 +
| X
 +
| Double
 +
| Absolute position (X coordinate)
 +
|-
 +
| Y
 +
| Double
 +
| Absolute position (Y coordinate)
 +
|-
 +
| Z
 +
| Double
 +
| Absolute position (Z coordinate)
 +
|-
 +
| Yaw
 +
| Float
 +
| Absolute rotation on the vertical axis, in degrees
 +
|-
 +
| Pitch
 +
| Float
 +
| Absolute rotation on the horizontal axis, in degrees
 +
|}
  
Further investigation shows that this is a multiple-block-change command; if you take the three arrays, and put together elements with the same index, and then decompose the short into coordinates (top 4 bits is X, next 4 bits is Z, bottom 8 bits is Y), you get things like [((8, 7, 4), 11, 0), ((7, 13, 6), 11, 0), ((13, 1, 8), 11, 0), ((7, 6, 6), 11, 0)].
+
==== Steer Boat ====
  
See the Block Change command for description of the general format of a block change.
+
Used to ''visually'' update whether boat paddles are turning.  The server will update the [[Entities#Boat|Boat entity metadata]] to match the values here.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="6" | 0x34
+
|rowspan="2"| 0x16
| class="col1 centeralign" | Chunk X
+
|rowspan="2"| Play
| class="col2 centeralign" | int
+
|rowspan="2"| Server
| class="col3 centeralign" | <code>-9</code>
+
| Left paddle turning
| class="col4" | Chunk X Coordinate
+
| Boolean
|- class="row2"
+
|
| class="col0 centeralign" | Chunk Z
+
|-
| class="col1 centeralign" | int
+
| Right paddle turning
| class="col2 centeralign" | <code>12</code>
+
| Boolean
| class="col3" | Chunk Z Coordinate
+
|
|- class="row3"
+
|}
| class="col0 centeralign" | Array size
+
 
| class="col1 centeralign" | short
+
Right paddle turning is set to true when the left button or forward button is held; left paddle turning is set to true when the right button or forward button is set to true.
| class="col2 centeralign" | <code>2</code>
+
 
| class="col3" | The total number of elements per array
+
==== Pick Item ====
|- class="row4"
 
| class="col0 centeralign" | Coordinate array
 
| class="col1 centeralign" | short array
 
| class="col2 centeralign" | <code>…</code>
 
| class="col3" | The coordinates of the blocks to change
 
|- class="row5"
 
| class="col0 centeralign" | Type array
 
| class="col1 centeralign" | byte array
 
| class="col2 centeralign" | <code>…</code>
 
| class="col3" | The type for each block change
 
|- class="row6"
 
| class="col0 centeralign" | Metadata array
 
| class="col1 centeralign" | byte array
 
| class="col2 centeralign" | <code>…</code>
 
| class="col3 leftalign" | The Metadata for each block changed
 
|- class="row7"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 11 bytes + Arrays
 
|}
 
  
=== Block Change (0x35) ===
+
Used to swap out an empty space on the hotbar with the item in the given inventory slot.  The Notchain client uses this for pick block functionality (middle click) to retrieve items from the inventory.
  
[[File:Icon_exclaim.gif|:!:]] Block metadata varies by block type - it should be <code>0x00</code> for most blocks with a few exceptions, shown in the table below.
 
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="5" | 0x35
+
|rowspan="1"| 0x17
| class="col1 centeralign" | X
+
|rowspan="1"| Play
| class="col2 centeralign" | int
+
|rowspan="1"| Server
| class="col3 centeralign" | <code>502</code>
+
| Slot to use
| class="col4" | Block X Coordinate
+
| VarInt
|- class="row2"
+
| See [[Inventory]]
| class="col0 centeralign" | Y
+
|}
| class="col1 centeralign" | byte
+
 
| class="col2 centeralign" | <code>71</code>
+
The server will first search the player's hotbar for an empty slot, starting from the current slot and looping around to the slot before it.  If there are no empty slots, it will start a second search from the current slot and find the first slot that does not contain an enchanted item.  If there still are no slots that meet that criteria, then the server will use the currently selected slot.
| class="col3" | Block Y Coordinate
+
 
|- class="row3"
+
After finding the appropriate slot, the server swaps the items and then send 3 packets:
| class="col0 centeralign" | Z
 
| class="col1 centeralign" | int
 
| class="col2 centeralign" | <code>18</code>
 
| class="col3" | Block Z Coordinate
 
|- class="row4"
 
| class="col0 centeralign" | Block Type
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>78</code>
 
| class="col3" | The new block type for the block
 
|- class="row5"
 
| class="col0 centeralign" | Block Metadata
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>0</code>
 
| class="col3" | The new Metadata for the block
 
|- class="row6"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 12 bytes
 
|}
 
  
=== Play Note Block (0x36) ===
+
* [[Protocol#Set slot|Set Slot]], with window ID set to -2 and slot set to the newly chosen slot and the item set to the item that is now in that slot (which was previously at the slot the client requested)
 +
* Set Slot, with window ID set to -2 and slot set to the slot the player requested, with the item that is now in that slot and was previously on the hotbar slot
 +
* [[Protocol#Held_Item_Change_.28clientbound.29|Held Item Change]], with the slot set to the newly chosen slot.
  
'''Server to Client only'''
+
==== Craft Recipe Request ====
  
This packet is sent to the client when a note block is played. It shows the note particle being emitted from the block as well as playing the tone.
+
This packet is sent when a player clicks a recipe in the crafting book that is craftable (white border).
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="5" | 0x35
+
|rowspan="3"| 0x18
| class="col1 centeralign" | X
+
|rowspan="3"| Play
| class="col2 centeralign" | int
+
|rowspan="3"| Server
| class="col3 centeralign" | <code>502</code>
+
| Window ID
| class="col4" | Block X Coordinate
+
| Byte
|- class="row2"
+
|
| class="col0 centeralign" | Y
+
|-
| class="col1 centeralign" | short
+
| Recipe
| class="col2 centeralign" | <code>71</code>
+
| Identifier
| class="col3" | Block Y Coordinate
+
| A recipe ID
|- class="row3"
+
|-
| class="col0 centeralign" | Z
+
| Make all
| class="col1 centeralign" | int
+
| Boolean
| class="col2 centeralign" | <code>18</code>
+
| Affects the amount of items processed; true if shift is down when clicked
| class="col3" | Block Z Coordinate
+
|}
|- class="row4"
+
 
| class="col0 centeralign" | Instrument Type
+
==== Player Abilities (serverbound) ====
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>3</code>
 
| class="col3" | The instrument type (see the table below).
 
|- class="row5"
 
| class="col0 centeralign" | Pitch
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>17</code>
 
| class="col3" | The pitch of the note (between 0-24 inclusive where 0 is the lowest and 24 is the highest).
 
|- class="row6"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 13 bytes
 
|}
 
  
Instrument Types
+
The latter 2 fields are used to indicate the walking and flying speeds respectively, while the first field is used to determine the value of 4 booleans.
 +
 
 +
The vanilla client sends this packet when the player starts/stops flying with the Flags parameter changed accordingly. All other parameters are ignored by the vanilla server.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Type ID
+
! State
! class="col1" | Type Name
+
! Bound To
|- class="row1"
+
! Field Name
| class="col0" | 0
+
! Field Type
| class="col1" | Harp
+
! Notes
|- class="row2"
+
|-
| class="col0" | 1
+
|rowspan="3"| 0x19
| class="col1" | Double Bass
+
|rowspan="3"| Play
|- class="row3"
+
|rowspan="3"| Server
| class="col0" | 2
+
| Flags
| class="col1" | Snare Drum
+
| Byte
|- class="row4"
+
| Bit mask. 0x08: damage disabled (god mode), 0x04: can fly, 0x02: is flying, 0x01: is Creative
| class="col0" | 3
+
|-
| class="col1" | Clicks/Sticks
+
| Flying Speed
|- class="row5"
+
| Float
| class="col0" | 4
+
|  
| class="col1" | Bass Drum
+
|-
|}
+
| Walking Speed
 +
| Float
 +
|  
 +
|}
  
More information about how the pitch values correspond to notes in real life are available on the [http://www.minecraftwiki.net/wiki/Note_Block official Minecraft wiki].
+
==== Player Digging ====
  
=== Explosion (0x3C) ===
+
Sent when the player mines a block. A Notchian server only accepts digging packets with coordinates within a 6-unit radius between the center of the block and 1.5 units from the player's feet (''not'' their eyes).
  
[[File:Icon_exclaim.gif|:!:]] This command is not fully understood.
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="3"| 0x1A
 +
|rowspan="3"| Play
 +
|rowspan="3"| Server
 +
| Status
 +
| VarInt Enum
 +
| The action the player is taking against the block (see below)
 +
|-
 +
| Location
 +
| Position
 +
| Block position
 +
|-
 +
| Face
 +
| Byte Enum
 +
| The face being hit (see below)
 +
|}
  
Seems to be sent when an explosion occurs (both creepers and TNT).
+
Status can be one of seven values:
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Value
! class="col0" | Packet ID
+
! Meaning
! class="col1" | Field Name
+
! Notes
! class="col2" | Field Type
+
|-
! class="col3" | Example
+
| 0
! class="col4" | Notes
+
| Started digging
|- class="row1"
+
|  
| class="col0 centeralign" rowspan=6 | 0x3C
+
|-
| class="col1 centeralign" | X
+
| 1
| class="col2 centeralign" | double
+
| Cancelled digging
| class="col3 centeralign" |
+
| Sent when the player lets go of the Mine Block key (default: left click)
| class="col4" |  
+
|-
|- class="row1"
+
| 2
| class="col1 centeralign" | Y
+
| Finished digging
| class="col2 centeralign" | double
+
| Sent when the client thinks it is finished
| class="col3 centeralign" |
+
|-
| class="col4" |
+
| 3
|- class="row1"
+
| Drop item stack
| class="col1 centeralign" | Z
+
| Triggered by using the Drop Item key (default: Q) with the modifier to drop the entire selected stack (default: depends on OS). Location is always set to 0/0/0, Face is always set to -Y.
| class="col2 centeralign" | double
+
|-
| class="col3 centeralign" |
+
| 4
| class="col4" |
+
| Drop item
|- class="row1"
+
| Triggered by using the Drop Item key (default: Q). Location is always set to 0/0/0, Face is always set to -Y.
| class="col1 centeralign" | Unknown
+
|-
| class="col2 centeralign" | float
+
| 5
| class="col3 centeralign" | 3.0
+
| Shoot arrow / finish eating
| class="col4" | radius?
+
| Indicates that the currently held item should have its state updated such as eating food, pulling back bows, using buckets, etc. Location is always set to 0/0/0, Face is always set to -Y.
|- class="row2"
+
|-
| class="col1 centeralign" | Record count
+
| 6
| class="col2 centeralign" | int
+
| Swap item in hand
| class="col3 centeralign" |
+
| Used to swap or assign an item to the second hand. Location is always set to 0/0/0, Face is always set to -Y.
| class="col4" | This is the count, not the size. The size is 3 times this value.
+
|}
|- class="row3"
 
| class="col1 centeralign" | Records
 
| class="col2 centeralign" | (byte, byte, byte) × count
 
| class="col3 centeralign" |
 
| class="col4" | Each record is 3 bytes, which seem to be XYZ offsets of affected blocks.
 
|- class="row4"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 33 bytes + 3*(Record count) bytes
 
|}
 
  
=== Open window (0x64) ===
+
The Face field can be one of the following values, representing the face being hit:
  
This is sent to the client when it should open an inventory, such as a chest, workbench, or furnace. This message is not sent anywhere for clients opening their own inventory.
+
{| class="wikitable"
 +
|-
 +
! Value
 +
! Offset
 +
! Face
 +
|-
 +
| 0
 +
| -Y
 +
| Bottom
 +
|-
 +
| 1
 +
| +Y
 +
| Top
 +
|-
 +
| 2
 +
| -Z
 +
| North
 +
|-
 +
| 3
 +
| +Z
 +
| South
 +
|-
 +
| 4
 +
| -X
 +
| West
 +
|-
 +
| 5
 +
| +X
 +
| East
 +
|}
 +
 
 +
==== Entity Action ====
 +
 
 +
Sent by the client to indicate that it has performed certain actions: sneaking (crouching), sprinting, exiting a bed, jumping with a horse, and opening a horse's inventory while riding it.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan=4 | 0x64
+
|rowspan="3"| 0x1B
| class="col1 centeralign" | Window id
+
|rowspan="3"| Play
| class="col2 centeralign" | byte
+
|rowspan="3"| Server
| class="col3 centeralign" | 123
+
| Entity ID
| class="col4" | The id of the window to display.
+
| VarInt
|- class="row1"
+
| Player ID
| class="col1 centeralign" | Inventory Type
+
|-
| class="col2 centeralign" | byte
+
| Action ID
| class="col3 centeralign" | 2
+
| VarInt Enum
| class="col4" | Check below
+
| The ID of the action, see below
|- class="row1"
+
|-
| class="col1 centeralign" | Window title
+
| Jump Boost
| class="col2 centeralign" | string
+
| VarInt
| class="col3 centeralign" | <code>Chest</code>
+
| Only used by the “start jump with horse” action, in which case it ranges from 0 to 100. In all other cases it is 0.
| class="col4" | The title of the window. One of "Chest", "Large chest", "Crafting", "Furnace", "Trap".
+
|}
|- class="row1"
 
| class="col1 centeralign" | Number of Slots
 
| class="col2 centeralign" | byte
 
| class="col3 centeralign" | 3
 
| class="col4" | Number of slots in the window (excluding the number of slots in the player inventory).
 
|- class="row2"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 4 bytes + 1 string
 
|}
 
  
The Window Title is probably ignored by notchian clients because the title for dispenser windows is "Dispenser", not "Trap" like this message says.
+
Action ID can be one of the following values:
  
Inventory Types
 
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! ID
! class="col0" | Inventory Type
+
! Action
! class="col1" | Description
+
|-
|- class="row1"
+
| 0
| class="col0" | 0
+
| Start sneaking
| class="col1" | Chest/Large chest
+
|-
|- class="row2"
+
| 1
| class="col0" | 1
+
| Stop sneaking
| class="col1" | Workbench
+
|-
|- class="row3"
+
| 2
| class="col0" | 2
+
| Leave bed
| class="col1" | Furnace
+
|-
|- class="row4"
+
| 3
| class="col0" | 3
+
| Start sprinting
| class="col1" | Dispenser
+
|-
|}
+
| 4
 +
| Stop sprinting
 +
|-
 +
| 5
 +
| Start jump with horse
 +
|-
 +
| 6
 +
| Stop jump with horse
 +
|-
 +
| 7
 +
| Open horse inventory
 +
|-
 +
| 8
 +
| Start flying with elytra
 +
|}
  
=== Close window (0x65) ===
+
Leave bed is only sent when the “Leave Bed” button is clicked on the sleep GUI, not when waking up due today time.
  
This packet is sent by the client when closing a window. This packet is sent from the server to the client when a window is forcibly closed, such as when a chest is destroyed while it's open.
+
Open horse inventory is only sent when pressing the inventory key (default: E) while on a horse — all other methods of opening a horse's inventory (involving right-clicking or shift-right-clicking it) do not use this packet.
  
Note, notchian clients send a close window message with window id 0 to close their inventory even though there is never an Open Window message for inventory.
+
==== Steer Vehicle ====
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" | 0x65
+
|rowspan="3"| 0x1C
| class="col1 centeralign" | Window id
+
|rowspan="3"| Play
| class="col2 centeralign" | byte
+
|rowspan="3"| Server
| class="col3 centeralign" | 0
+
| Sideways
| class="col4" | This is the id of the window that was closed. 0 for inventory.
+
| Float
|- class="row2"
+
| Positive to the left of the player
! class="col0" | Total Size:
+
|-
| class="col1 rightalign" colspan="4" | 2 bytes
+
| Forward
|}
+
| Float
 +
| Positive forward
 +
|-
 +
| Flags
 +
| Unsigned Byte
 +
| Bit mask. 0x1: jump, 0x2: unmount
 +
|}
 +
 
 +
Also known as 'Input' packet.
 +
 
 +
==== Recipe Book Data ====
  
=== Window click (0x66) ===
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
!colspan="2"| Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="11"| 0x1D
 +
|rowspan="11"| Play
 +
|rowspan="11"| Server
 +
|colspan="2"| Type
 +
| VarInt
 +
| Determines the format of the rest of the packet
 +
|-
 +
! Type
 +
! Field Name
 +
!
 +
!
 +
|-
 +
| 0: Displayed Recipe
 +
| Recipe ID
 +
| Identifier
 +
| A recipe ID
 +
|-
 +
|rowspan="8"| 1: Recipe Book States
 +
| Crafting Recipe Book Open
 +
| Boolean
 +
| Whether the player has the crafting recipe book currently opened/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 opened/active.
 +
|-
 +
| Smelting Recipe Filter Active
 +
| Boolean
 +
| Whether the player has the smelting recipe book filter option currently active.
 +
|-
 +
| Blasting Recipe Book Open
 +
| Boolean
 +
| May be swapped with smoking recipe book.  Also, the notchian client appears to use the same value for both of those books currently.
 +
|-
 +
| Blasting Recipe Filter Active
 +
| Boolean
 +
| May be swapped with smoking recipe book.  Also, the notchian client appears to use the same value for both of those books currently.
 +
|-
 +
| Smoking Recipe Book Open
 +
| Boolean
 +
|
 +
|-
 +
| Smoking Recipe Filter Active
 +
| Boolean
 +
|
 +
|}
  
'''Client to Server only'''
+
The Recipe Book Status type is sent when one of the states changes.
  
[[File:Icon_exclaim.gif|:!:]] This command is not fully understood.
+
==== Name Item ====
  
This packet is sent by the player when it clicks on a slot in a window.
+
Sent as a player is renaming an item in an anvil (each keypress in the anvil UI sends a new Name Item packet).  If the new name is empty, then the item loses its custom name (this is different from setting the custom name to the normal name of the item).  The item name may be no longer than 35 characters long, and if it is longer than that, then the rename is silently ignored.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan=7 | 0x66
+
|rowspan="1"| 0x1E
| class="col1 centeralign" | Window id
+
|rowspan="1"| Play
| class="col2 centeralign" | byte
+
|rowspan="1"| Server
| class="col3 centeralign" | <code>0</code>
+
| Item name
| class="col4" | The id of the window which was clicked. 0 for player inventory.
+
| String (32767)
|- class="row2"
+
| The new name of the item
| class="col0 centeralign" | Slot
+
|}
| class="col1 centeralign" | short
 
| class="col2 centeralign" | <code>36</code>
 
| class="col3" | The clicked slot. See below.
 
|- class="row3"
 
| class="col0 centeralign" | Right-click
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>1</code>
 
| class="col3" | 1 when right-clicking and otherwise 0.
 
|- class="row4"
 
| class="col0 centeralign" | Action number
 
| class="col1 centeralign" | short
 
| class="col2 centeralign" | <code>12</code>
 
| class="col3" | A unique number for the action, used for transaction handling (See the Transaction packet).
 
|- class="row5"
 
| class="col0 centeralign" | Item ID
 
| class="col1 centeralign" | short
 
| class="col2 centeralign" | <code>3</code>
 
| class="col3" | ID of Item that was in the slot or -1 if no item. If -1, this is the last field in the packet.
 
|- class="row6"
 
| class="col0 centeralign" | Item count
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>64</code>
 
| class="col3" | Number of items that were in the slot
 
|- class="row7"
 
| class="col0 centeralign" | Item uses
 
| class="col1 centeralign" | short
 
| class="col2 centeralign" | <code>10</code>
 
| class="col3" | Number of times the item was used that was in the slot
 
|- class="row8"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 9 bytes (+3 for item ID != -1)
 
|}
 
  
The slot number is calculated starting at 0, counting up through the window's unique slots, and then counting through the players inventory. The number of unique slots in the window is in the Open Window message for all window types except the default inventory window, in which the number of unique slots is 9. This means the slot in the upper-left corner of the player's inventory is slot ''n'' where ''n'' is the number of unique slots. Slot number -999 is for clicking outside the window.
+
==== Resource Pack Status ====
  
Rectangular regions are always indexed starting with the upper-left corner and scanning across rows. If a window has a crafting region, the output slot is always slot 0 followed immediately by the input region.
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="1"| 0x1F
 +
|rowspan="1"| Play
 +
|rowspan="1"| Server
 +
| Result
 +
| VarInt Enum
 +
| 0: successfully loaded, 1: declined, 2: failed download, 3: accepted
 +
|}
  
=== Set slot (0x67) ===
+
==== Advancement Tab ====
  
'''Server to Client only'''
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x20
 +
|rowspan="2"| Play
 +
|rowspan="2"| Server
 +
| Action
 +
| VarInt enum
 +
| 0: Opened tab, 1: Closed screen
 +
|-
 +
| Tab ID
 +
| Optional identifier
 +
| Only present if action is Opened tab
 +
|}
  
[[File:Icon_exclaim.gif|:!:]] This command is not fully understood.
+
==== Select Trade ====
  
Sent by the server when an item in a slot (in a window) is added/removed.
+
When a player selects a specific trade offered by a villager NPC.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan=5 | 0x67
+
|rowspan="1"| 0x21
| class="col1 centeralign" | Window id
+
|rowspan="1"| Play
| class="col2 centeralign" | byte
+
|rowspan="1"| Server
| class="col3 centeralign" | <code>0</code>
+
| Selected slot
| class="col4" | The window which is being updated. 0 for player inventory. Note that all known window types include the player inventory. This packet will only be sent for the currently opened window while the player is performing actions, even if it affects the player inventory. After the window is closed, a number of these packets are sent to update the player's inventory window (0).
+
| VarInt
|- class="row2"
+
| The selected slot int the players current (trading) inventory. (Was a full Integer for the plugin message)
| class="col0 centeralign" | Slot
+
|}
| class="col1 centeralign" | short
+
 
| class="col2 centeralign" | <code>36</code>
+
==== Set Beacon Effect ====
| class="col3" | The slot that should be updated
 
|- class="row3"
 
| class="col0 centeralign" | Item ID
 
| class="col1 centeralign" | short
 
| class="col2 centeralign" | <code>-1</code>
 
| class="col3" | When -1, this is the last value in this packet. -1 means no item.
 
|- class="row4"
 
| class="col0 centeralign" | Item Count
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>64</code>
 
| class="col3" | Number of items in a stack
 
|- class="row5"
 
| class="col0 centeralign" | Item uses
 
| class="col1 centeralign" | short
 
| class="col2 centeralign" | <code>3</code>
 
| class="col3" |
 
|- class="row8"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 6 bytes (+3 for item ID != -1)
 
|}
 
  
Note that if window ID and slot are both -1, it means the item currently attached to the cursor.
+
Changes the effect of the current beacon.
  
Slots: [http://gyazo.com/9d52e1fd4dc14790ec66eab4a9aee00e.png]
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="2"| 0x22
 +
|rowspan="2"| Play
 +
|rowspan="2"| Server
 +
| Primary Effect
 +
| VarInt
 +
| A [http://minecraft.gamepedia.com/Data_values#Potions Potion ID]. (Was a full Integer for the plugin message)
 +
|-
 +
| Secondary Effect
 +
| VarInt
 +
| A [http://minecraft.gamepedia.com/Data_values#Potions Potion ID]. (Was a full Integer for the plugin message)
 +
|}
  
=== Window items (0x68) ===
+
==== Held Item Change (serverbound) ====
  
'''Server to Client only'''
+
Sent when the player changes the slot selection
  
[[File:Inventory-slots.png|thumb|The inventory slots]]
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="1"| 0x23
 +
|rowspan="1"| Play
 +
|rowspan="1"| Server
 +
| Slot
 +
| Short
 +
| The slot which the player has selected (0–8)
 +
|}
  
Sent by the server when an item in a slot (in a window) is added/removed. This includes the main inventory, equipped armour and crafting slots.
+
==== Update Command Block ====
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="3" | 0x68
+
|rowspan="5"| 0x24
| class="col1 centeralign" | Window id
+
|rowspan="5"| Play
| class="col2 centeralign" | byte
+
|rowspan="5"| Server
| class="col3 centeralign" | <code>1</code>
+
|-
| class="col4" | The id of window which items are being sent for. 0 for player inventory.
+
| Location
|- class="row2"
+
| Position
| class="col0 centeralign" | Count
+
|
| class="col1 centeralign" | short
+
|-
| class="col2 centeralign" | <code>4</code>
+
| Command
| class="col3" | The number of items (see below)
+
| String (32767)
|- class="row3"
+
|
| class="col0 centeralign" | Payload
+
|-
| class="col1 centeralign" | …
+
| Mode || VarInt enum || One of SEQUENCE (0), AUTO (1), or REDSTONE (2)  
| class="col2 centeralign" | <code></code>
+
|-
| class="col3" | The payload (see below)
+
| Flags
|- class="row4"
+
| Byte
! class="col0" | Total Size:
+
| 0x01: Track Output (if false, the output of the previous command will not be stored within the command block); 0x02: Is conditional; 0x04: Automatic
| class="col1 rightalign" colspan="4" | 4 bytes + size of payload
+
|}
|}
+
 
 +
==== Update Command Block Minecart ====
  
This packet is a bit trickier to parse than most others because the size of its payload is variable. The payload is an array of shorts (item ID) optionally followed by a byte-short pair (count and uses) as long as the item ID does not equal <code>-1</code>, which signifies an empty slot.
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="3"| 0x25
 +
|rowspan="3"| Play
 +
|rowspan="3"| Server
 +
| Entity ID
 +
| VarInt
 +
|
 +
|-
 +
| Command
 +
| String
 +
|
 +
|-
 +
| Track Output
 +
| Boolean
 +
| If false, the output of the previous command will not be stored within the command block.
 +
|}
  
Uses is the number of times an item has been used (the value starts at 0 and counts up.) Note that an invalid use of an item may count as 2 uses.
+
==== Creative Inventory Action ====
  
<syntaxhighlight lang="python">
+
While the user is in the standard inventory (i.e., not a crafting bench) in Creative mode, the player will send this packet.
offset = 0
 
 
for slot in count:
 
    item_id = payload[offset] as short
 
    offset += 2
 
    if item_id is not equal to -1:
 
        count = payload[offset] as byte
 
        offset += 1
 
        uses = payload[offset] as short
 
        offset += 2
 
        inventory[slot] = new item(item_id, count, uses)
 
    else:
 
        inventory[slot] = None
 
</syntaxhighlight>
 
  
=== Update progress bar (0x69) ===
+
Clicking in the creative inventory menu is quite different from non-creative inventory management. Picking up an item with the mouse actually deletes the item from the server, and placing an item into a slot or dropping it out of the inventory actually tells the server to create the item from scratch. (This can be verified by clicking an item that you don't mind deleting, then severing the connection to the server; the item will be nowhere to be found when you log back in.) As a result of this implementation strategy, the "Destroy Item" slot is just a client-side implementation detail that means "I don't intend to recreate this item.". Additionally, the long listings of items (by category, etc.) are a client-side interface for choosing which item to create. Picking up an item from such listings sends no packets to the server; only when you put it somewhere does it tell the server to create the item in that location.
  
'''Server to Client only'''
+
This action can be described as "set inventory slot". Picking up an item sets the slot to item ID -1. Placing an item into an inventory slot sets the slot to the specified item. Dropping an item (by clicking outside the window) effectively sets slot -1 to the specified item, which causes the server to spawn the item entity, etc.. All other inventory slots are numbered the same as the non-creative inventory (including slots for the 2x2 crafting menu, even though they aren't visible in the vanilla client).
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan=3 | 0x69
+
|rowspan="2"| 0x26
| class="col1 centeralign" | Window id
+
|rowspan="2"| Play
| class="col2 centeralign" | byte
+
|rowspan="2"| Server
| class="col3 centeralign" | 2
+
| Slot
| class="col4" | The id of the window that the progress bar is in.
+
| Short
|- class="row1"
+
| Inventory slot
| class="col1 centeralign" | Progress bar
+
|-
| class="col2 centeralign" | short
+
| Clicked Item
| class="col3 centeralign" | 1
+
| [[Slot Data|Slot]]
| class="col4" | Which of the progress bars that should be updated. (For furnaces, 0 = progress arrow, 1 = fire icon)
+
|  
|- class="row1"
+
|}
| class="col1 centeralign" | Value
+
 
| class="col2 centeralign" | short
+
==== Update Jigsaw Block ====
| class="col3 centeralign" | 650
 
| class="col4" | The value of the progress bar. The maximum values vary depending on the progress bar. Presumably the values are specified as in-game ticks. Some progress bar values increase, while others decrease. For furnaces, 0 is empty, full progress arrow = about 180, full fire icon = about 250)
 
|- class="row2"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 6 bytes
 
|}
 
  
=== Transaction (0x6A) ===
+
Sent when Done is pressed on the {{Minecraft Wiki|Jigsaw Block}} interface.
  
'''Server to Client only'''
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="4"| 0x27
 +
|rowspan="4"| Play
 +
|rowspan="4"| Server
 +
| Location
 +
| Position
 +
| Block entity location
 +
|-
 +
| Attachment type
 +
| Identifier
 +
|
 +
|-
 +
| Target pool
 +
| Identifier
 +
|
 +
|-
 +
| Final state
 +
| String
 +
| "Turns into" on the GUI, <code>final_state</code> in NBT
 +
|}
  
A packet from the server indicating whether a request from the client was accepted, or whether there was a conflict (due to lag).
+
==== Update Structure Block ====
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan=3 | 0x6A
+
|rowspan="17"| 0x28
| class="col1 centeralign" | Window id
+
|rowspan="17"| Play
| class="col2 centeralign" | byte
+
|rowspan="17"| Server
| class="col3 centeralign" | 0
+
|-
| class="col4" | The id of the window that the action occurred in.
+
| Location
|- class="row1"
+
| Position
| class="col1 centeralign" | Action number
+
| Block entity location
| class="col2 centeralign" | short
+
|-
| class="col3 centeralign" | 12
+
| Action
| class="col4" | Every action that is to be accepted has a unique number. This field corresponds to that number.
+
| VarInt enum
|- class="row1"
+
| An additional action to perform beyond simply saving the given data; see below
| class="col1 centeralign" | Accepted?
+
|-
| class="col2 centeralign" | boolean
+
| Mode
| class="col3 centeralign" | true
+
| VarInt enum
| class="col4" | Whether the action was accepted.
+
| One of SAVE (0), LOAD (1), CORNER (2), DATA (3).
|- class="row2"
+
|-
! class="col0" | Total Size:
+
| Name
| class="col1 rightalign" colspan="4" | 5 bytes
+
| String
|}
+
|
 +
|-
 +
| Offset X || Byte
 +
| Between -32 and 32
 +
|-
 +
| Offset Y || Byte
 +
| Between -32 and 32
 +
|-
 +
| Offset Z || Byte
 +
| Between -32 and 32
 +
|-
 +
| Size X || Byte
 +
| Between 0 and 32
 +
|-
 +
| Size Y || Byte
 +
| Between 0 and 32
 +
|-
 +
| Size Z || Byte
 +
| Between 0 and 32
 +
|-
 +
| Mirror
 +
| VarInt enum
 +
| One of NONE (0), LEFT_RIGHT (1), FRONT_BACK (2).
 +
|-
 +
| Rotation
 +
| VarInt enum
 +
| One of NONE (0), CLOCKWISE_90 (1), CLOCKWISE_180 (2), COUNTERCLOCKWISE_90 (3).
 +
|-
 +
| Metadata
 +
| String
 +
|
 +
|-
 +
| Integrity
 +
| Float
 +
| Between 0 and 1
 +
|-
 +
|Seed
 +
|VarLong
 +
|
 +
|-
 +
| Flags
 +
| Byte
 +
| 0x01: Ignore entities; 0x02: Show air; 0x04: Show bounding box
 +
|}
 +
 
 +
Possible actions:
 +
 
 +
* 0 - Update data
 +
* 1 - Save the structure
 +
* 2 - Load the structure
 +
* 3 - Detect size
 +
 
 +
The Notchian client uses update data to indicate no special action should be taken (i.e. the done button).
 +
 
 +
==== Update Sign ====
 +
 
 +
{{anchor|Update Sign (serverbound)}}This message is sent from the client to the server when the “Done” button is pushed after placing a sign.
  
=== Update Sign (0x82) ===
+
The server only accepts this packet after [[#Open Sign Editor|Open Sign Editor]], otherwise this packet is silently ignored.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan=7 | 0x82
+
|rowspan="5"| 0x29
| class="col1 centeralign" | X
+
|rowspan="5"| Play
| class="col2 centeralign" | int
+
|rowspan="5"| Server
| class="col3 centeralign" | 128
+
| Location
| class="col4" | Block X Coordinate
+
| Position
|- class="row1"
+
| Block Coordinates
| class="col1 centeralign" | Y
+
|-
| class="col2 centeralign" | short
+
| Line 1
| class="col3 centeralign" | 0
+
| String (384)
| class="col4" | Block Y Coordinate
+
| First line of text in the sign
|- class="row1"
+
|-
| class="col1 centeralign" | Z
+
| Line 2
| class="col2 centeralign" | int
+
| String (384)
| class="col3 centeralign" | -128
+
| Second line of text in the sign
| class="col4" | Block Z Coordinate
+
|-
|- class="row1"
+
| Line 3
| class="col1 centeralign" | Text1
+
| String (384)
| class="col2 centeralign" | string
+
| Third line of text in the sign
| class="col3 centeralign" | <code>First line</code>
+
|-
| class="col4" | First line of text in the sign
+
| Line 4
|- class="row1"
+
| String (384)
| class="col1 centeralign" | Text2
+
| Fourth line of text in the sign
| class="col2 centeralign" | string
+
|}
| class="col3 centeralign" | <code>Second line</code>
 
| class="col4" | Second line of text in the sign
 
|- class="row1"
 
| class="col1 centeralign" | Text3
 
| class="col2 centeralign" | string
 
| class="col3 centeralign" | <code>Third line</code>
 
| class="col4" | Third line of text in the sign
 
|- class="row1"
 
| class="col1 centeralign" | Text4
 
| class="col2 centeralign" | string
 
| class="col3 centeralign" | <code>Fourth line</code>
 
| class="col4" | Fourth line of text in the sign
 
|- class="row2"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 11 bytes + 4 strings
 
|}
 
  
=== Disconnect/Kick (0xFF) ===
+
==== Animation (serverbound) ====
  
Sent by the server before it disconnects a client, or by the client before it disconnects from the server. The receiver of this packet assumes that the sender has already closed the connection by the time the packet arrives.
+
Sent when the player's arm swings.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
! class="col1" | Field Name
+
! Bound To
! class="col2" | Field Type
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" | 0xFF
+
| 0x2A
| class="col1 centeralign" | Reason
+
| Play
| class="col2 centeralign" | string
+
| Server
| class="col3 centeralign" | <code>The server is full!</code>
+
| Hand
| class="col4" | Displayed to the client when the connection terminates
+
| VarInt Enum
|- class="row2"
+
| Hand used for the animation. 0: main hand, 1: off hand.
! class="col0" | Total Size:
+
|}
| class="col1 rightalign" colspan="4" | 3 bytes + length of strings
+
 
|}
+
==== Spectate ====
 +
 
 +
Teleports the player to the given entity.  The player must be in spectator mode.
  
== Protocol History ==
+
The Notchian client only uses this to teleport to players, but it appears to accept any type of entity.  The entity does not need to be in the same dimension as the player; if necessary, the player will be respawned in the right world.  If the given entity cannot be found (or isn't loaded), this packet will be ignored.  It will also be ignored if the player attempts to teleport to themselves.
  
Provided below is a changelog of the server protocol starting on 2010-08-20.  The wiki history feature may also be used to investigate changes.
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="1"| 0x2B
 +
|rowspan="1"| Play
 +
|rowspan="1"| Server
 +
| Target Player
 +
| UUID
 +
| UUID of the player to teleport to (can also be an entity UUID)
 +
|}
  
=== 2011-1-13 ===
+
==== Player Block Placement ====
* <div class="li">Beta 1.2 released.</div>
 
* More packet changes ([http://pastebin.com/HHW52Awn pastebin]): 0x05, 0x0F, 0x13, 0x15, 0x18, 0x19, 0x28, 0x36, 0x66, 0x67.
 
  
=== 2010-12-20 ===
+
{| class="wikitable"
* <div class="li">Notch released Beta on time! Amazing! Refactored the page to be slightly smaller and easier to navigate.</div>
+
|-
* A whole host of packet changes. 0x05, 0x08, 0x10, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, and 0x82. Packets 0x11 and 0x3b removed.
+
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="7"| 0x2C
 +
|rowspan="7"| Play
 +
|rowspan="7"| Server
 +
| Hand
 +
| VarInt Enum
 +
| The hand from which the block is placed; 0: main hand, 1: off hand
 +
|-
 +
| Location
 +
| Position
 +
| Block position
 +
|-
 +
| Face
 +
| VarInt Enum
 +
| The face on which the block is placed (as documented at [[#Player Digging|Player Digging]])
 +
|-
 +
| Cursor Position X
 +
| Float
 +
| The position of the crosshair on the block, from 0 to 1 increasing from west to east
 +
|-
 +
| Cursor Position Y
 +
| Float
 +
| The position of the crosshair on the block, from 0 to 1 increasing from bottom to top
 +
|-
 +
| Cursor Position Z
 +
| Float
 +
| The position of the crosshair on the block, from 0 to 1 increasing from north to south
 +
|-
 +
| Inside block
 +
| Boolean
 +
| True when the player's head is inside of a block.
 +
|}
  
=== 2010-12-01 ===
+
Upon placing a block, this packet is sent once.
* <div class="li"> Protocol version changed to 6</div>
 
* <div class="li"> Packet 0x12 ([[#Animation_.280x12.29|Animation]]) got a lot more new values</div>
 
* <div class="li"> Packet 0x26 changed, now indicates entity damage, death and explosion (for creepers, TNT not tested)</div>
 
* <div class="li"> Packet 0x3B now being sent from client</div>
 
* <div class="li"> Packet 0x3C added</div>
 
* (need info on other changes)
 
  
=== 2010-11-24 ===
+
The Cursor Position X/Y/Z fields (also known as in-block coordinates) are calculated using raytracing. The unit corresponds to sixteen pixels in the default resource pack. For example, let's say a slab is being placed against the south face of a full block. The Cursor Position X will be higher if the player was pointing near the right (east) edge of the face, lower if pointing near the left. The Cursor Position Y will be used to determine whether it will appear as a bottom slab (values 0.0–0.5) or as a top slab (values 0.5-1.0). The Cursor Position Z should be 1.0 since the player was looking at the southernmost part of the block.
* <div class="li"> Protocol version changed to 5</div>
 
* <div class="li"> Packet 0x07 ([[#Use_Entity.3F_.280x07.29|Use Entity]]) got a new field (byte)</div>
 
* <div class="li"> Packet 0x08 ([[#Update Health (0x08)|Update Health]]) added</div>
 
* <div class="li"> Packet 0x09 ([[#Respawn (0x09)|Respawn]]) added</div>
 
* <div class="li"> Packet 0x12 ([[#Animation_.280x12.29|Animation]]) started getting non-boolean values for the Animation field</div>
 
* <div class="li"> Packet 0x26 (Entity Death) added</div>
 
  
=== 2010-11-10 ===
+
Inside block is true when a player's head (specifically eyes) are inside of a block's collision. In 1.13 and later versions, collision is rather complicated and individual blocks can have multiple collision boxes. For instance, a ring of vines has a non-colliding hole in the middle. This value is only true when the player is directly in the box. In practice, though, this value is only used by scaffolding to place in front of the player when sneaking inside of it (other blocks will place behind when you intersect with them -- try with glass for instance).
* <div class="li"> Protocol version changed to 4</div>
 
* <div class="li"> Packet 0x01 ([[#Login_Request_.280x01.29|login request]]) changed</div>
 
* <div class="li"> Packet 0x07 ([[#Use Entity? (0x07)|Use Entity?]]) added</div>
 
* <div class="li"> Packet 0x1C ([[#Entity Velocity? (0x1C)|Entity Velocity?]]) added</div>
 
* <div class="li"> Packet 0x27 ([[#Attach Entity? (0x27)|Attach Entity?]]) added</div>
 
  
=== 2010-10-31 ===
+
==== Use Item ====
* <div class="li"> Protocol version changed to 3</div>
 
* <div class="li"> Packet 0x01 ([[#Login_Request_.280x01.29|login request]]) changed</div>
 
  
=== 2010-09-10 ===
+
Sent when pressing the Use Item key (default: right click) with an item in hand.
* <div class="li"> Protocol version changed to 2</div>
 
* <div class="li"> Packets 0x05, 0x06, 0x3B added</div>
 
* <div class="li"> Server-side inventory (no verification)</div>
 
* <div class="li"> Vanilla adds experimental monsters (only damaged by fire)</div>
 
  
=== 2010-08-20 ===
+
{| class="wikitable"
* <div class="li"> Protocol version reset from 14 to 1</div>
+
! Packet ID
* <div class="li"> Packet 0x04 ([[#Time_Update_.280x04.29|time update]]) added</div>
+
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x2D
 +
| Play
 +
| Server
 +
| Hand
 +
| VarInt Enum
 +
| Hand used for the animation. 0: main hand, 1: off hand.
 +
|}
  
 
[[Category:Protocol Details]]
 
[[Category:Protocol Details]]
[[Category:Minecraft Alpha]]
+
[[Category:Minecraft Modern]]

Revision as of 20:26, 1 July 2020

Heads up!

This article is about the protocol for the latest stable release of Minecraft Java Edition (1.15.2, protocol 578). For the Java Edition pre-releases, see Pre-release protocol. For the incomplete Bedrock Edition docs, see Bedrock Protocol. For the old Pocket Edition, see Pocket Edition Protocol Documentation.

This page presents a dissection of the current Minecraft protocol.

If you're having trouble, check out the FAQ or ask for help in the IRC channel #mcdevs on chat.freenode.net (More Information).

Note: While you may use the contents of this page without restriction to create servers, clients, bots, etc… you still need to provide attribution to #mcdevs if you copy any of the contents of this page for publication elsewhere.

The changes between versions may be viewed at Protocol History.

Contents

Definitions

The Minecraft server accepts connections from TCP clients and communicates with them using packets. A packet is a sequence of bytes sent over the TCP connection. The meaning of a packet depends both on its packet ID and the current state of the connection. The initial state of each connection is Handshaking, and state is switched using the packets Handshake and Login Success.

Data types

All data sent over the network (except for VarInt and VarLong) is big-endian, that is the bytes are sent from most significant byte to least significant byte. The majority of everyday computers are little-endian, therefore it may be necessary to change the endianness before sending data over the network.


Name Size (bytes) Encodes Notes
Boolean 1 Either false or true True is encoded as 0x01, false as 0x00.
Byte 1 An integer between -128 and 127 Signed 8-bit integer, two's complement
Unsigned Byte 1 An integer between 0 and 255 Unsigned 8-bit integer
Short 2 An integer between -32768 and 32767 Signed 16-bit integer, two's complement
Unsigned Short 2 An integer between 0 and 65535 Unsigned 16-bit integer
Int 4 An integer between -2147483648 and 2147483647 Signed 32-bit integer, two's complement
Long 8 An integer between -9223372036854775808 and 9223372036854775807 Signed 64-bit integer, two's complement
Float 4 A single-precision 32-bit IEEE 754 floating point number
Double 8 A double-precision 64-bit IEEE 754 floating point number
String (n) ≥ 1
≤ (n×3) + 3
A sequence of Unicode scalar values UTF-8 string prefixed with its size in bytes as a VarInt. Maximum length of n characters, which varies by context. The encoding used on the wire is regular UTF-8, not Java's "slight modification". However, the length of the string for purposes of the length limit is its number of UTF-16 code units, that is, scalar values > U+FFFF are counted as two. Up to n × 3 bytes can be used to encode a UTF-8 string comprising n code units when converted to UTF-16, and both of those limits are checked. Maximum n value is 32767. The + 3 is due to the max size of a valid length VarInt.
Text Component Varies See Text formatting#Text components Encoded as a NBT Tag, with the type of tag used depending on the case:
  • As a String Tag: For components only containing text (no styling, no events etc.).
  • As a Compound Tag: Every other case.
JSON Text Component ≥ 1
≤ (262144×3) + 3
See Text formatting#Text components Encoded as a String with max length of 262144.
Identifier ≥ 1
≤ (32767×3) + 3
See Identifier below Encoded as a String with max length of 32767.
VarInt ≥ 1
≤ 5
An integer between -2147483648 and 2147483647 Variable-length data encoding a two's complement signed 32-bit integer; more info in their section
VarLong ≥ 1
≤ 10
An integer between -9223372036854775808 and 9223372036854775807 Variable-length data encoding a two's complement signed 64-bit integer; more info in their section
Entity Metadata Varies Miscellaneous information about an entity See Entity_metadata#Entity Metadata Format
Slot Varies An item stack in an inventory or container See Slot Data
NBT Varies Depends on context See NBT
Position 8 An integer/block position: x (-33554432 to 33554431), z (-33554432 to 33554431), y (-2048 to 2047) x as a 26-bit integer, followed by z as a 26-bit integer, followed by y as a 12-bit integer (all signed, two's complement). See also the section below.
Angle 1 A rotation angle in steps of 1/256 of a full turn Whether or not this is signed does not matter, since the resulting angles are the same.
UUID 16 A UUID Encoded as an unsigned 128-bit integer (or two unsigned 64-bit integers: the most significant 64 bits and then the least significant 64 bits)
BitSet Varies See #BitSet below A length-prefixed bit set.
Fixed BitSet (n) n See #Fixed BitSet below A bit set with a fixed length of n bits.
Optional X 0 or size of X A field of type X, or nothing Whether or not the field is present must be known from the context.
Array of X count times size of X Zero or more fields of type X The count must be known from the context.
X Enum size of X A specific value from a given list The list of possible values and how each is encoded as an X must be known from the context. An invalid value sent by either side will usually result in the client being disconnected with an error or even crashing.
Byte Array Varies Depends on context This is just a sequence of zero or more bytes, its meaning should be explained somewhere else, e.g. in the packet description. The length must also be known from the context.

Identifier

Identifiers are a namespaced location, in the form of minecraft:thing. If the namespace is not provided, it defaults to minecraft (i.e. thing is minecraft:thing). Custom content should always be in its own namespace, not the default one. Both the namespace and value can use all lowercase alphanumeric characters (a-z and 0-9), dot (.), dash (-), and underscore (_). In addition, values can use slash (/). The naming convention is lower_case_with_underscores. More information. For ease of determining whether a namespace or value is valid, here are regular expressions for each:

  • Namespace: [a-z0-9.-_]
  • Value: [a-z0-9.-_/]

VarInt and VarLong

Variable-length format such that smaller numbers use fewer bytes. These are very similar to Protocol Buffer Varints: the 7 least significant bits are used to encode the value and the most significant bit indicates whether there's another byte after it for the next part of the number. The least significant group is written first, followed by each of the more significant groups; thus, VarInts are effectively little endian (however, groups are 7 bits, not 8).

VarInts are never longer than 5 bytes, and VarLongs are never longer than 10 bytes. Within these limits, unnecessarily long encodings (e.g. 81 00 to encode 1) are allowed.

Pseudocode to read and write VarInts and VarLongs:

private static final int SEGMENT_BITS = 0x7F;
private static final int CONTINUE_BIT = 0x80;
public int readVarInt() {
    int value = 0;
    int position = 0;
    byte currentByte;

    while (true) {
        currentByte = readByte();
        value |= (currentByte & SEGMENT_BITS) << position;

        if ((currentByte & CONTINUE_BIT) == 0) break;

        position += 7;

        if (position >= 32) throw new RuntimeException("VarInt is too big");
    }

    return value;
}
public long readVarLong() {
    long value = 0;
    int position = 0;
    byte currentByte;

    while (true) {
        currentByte = readByte();
        value |= (long) (currentByte & SEGMENT_BITS) << position;

        if ((currentByte & CONTINUE_BIT) == 0) break;

        position += 7;

        if (position >= 64) throw new RuntimeException("VarLong is too big");
    }

    return value;
}
public void writeVarInt(int value) {
    while (true) {
        if ((value & ~SEGMENT_BITS) == 0) {
            writeByte(value);
            return;
        }

        writeByte((value & SEGMENT_BITS) | CONTINUE_BIT);

        // Note: >>> means that the sign bit is shifted with the rest of the number rather than being left alone
        value >>>= 7;
    }
}
public void writeVarLong(long value) {
    while (true) {
        if ((value & ~((long) SEGMENT_BITS)) == 0) {
            writeByte(value);
            return;
        }

        writeByte((value & SEGMENT_BITS) | CONTINUE_BIT);

        // Note: >>> means that the sign bit is shifted with the rest of the number rather than being left alone
        value >>>= 7;
    }
}

Warning.png Note Minecraft's VarInts are identical to LEB128 with the slight change of throwing a exception if it goes over a set amount of bytes.

Warning.png Note that Minecraft's VarInts are not encoded using Protocol Buffers; it's just similar. If you try to use Protocol Buffers Varints with Minecraft's VarInts, you'll get incorrect results in some cases. The major differences:

  • Minecraft's VarInts are all signed, but do not use the ZigZag encoding. Protocol buffers have 3 types of Varints: uint32 (normal encoding, unsigned), sint32 (ZigZag encoding, signed), and int32 (normal encoding, signed). Minecraft's are the int32 variety. Because Minecraft uses the normal encoding instead of ZigZag encoding, negative values always use the maximum number of bytes.
  • Minecraft's VarInts are never longer than 5 bytes and its VarLongs will never be longer than 10 bytes, while Protocol Buffer Varints will always use 10 bytes when encoding negative numbers, even if it's an int32.

Sample VarInts:

Value Hex bytes Decimal bytes
0 0x00 0
1 0x01 1
2 0x02 2
127 0x7f 127
128 0x80 0x01 128 1
255 0xff 0x01 255 1
25565 0xdd 0xc7 0x01 221 199 1
2097151 0xff 0xff 0x7f 255 255 127
2147483647 0xff 0xff 0xff 0xff 0x07 255 255 255 255 7
-1 0xff 0xff 0xff 0xff 0x0f 255 255 255 255 15
-2147483648 0x80 0x80 0x80 0x80 0x08 128 128 128 128 8

Sample VarLongs:

Value Hex bytes Decimal bytes
0 0x00 0
1 0x01 1
2 0x02 2
127 0x7f 127
128 0x80 0x01 128 1
255 0xff 0x01 255 1
2147483647 0xff 0xff 0xff 0xff 0x07 255 255 255 255 7
9223372036854775807 0xff 0xff 0xff 0xff 0xff 0xff 0xff 0xff 0x7f 255 255 255 255 255 255 255 255 127
-1 0xff 0xff 0xff 0xff 0xff 0xff 0xff 0xff 0xff 0x01 255 255 255 255 255 255 255 255 255 1
-2147483648 0x80 0x80 0x80 0x80 0xf8 0xff 0xff 0xff 0xff 0x01 128 128 128 128 248 255 255 255 255 1
-9223372036854775808 0x80 0x80 0x80 0x80 0x80 0x80 0x80 0x80 0x80 0x01 128 128 128 128 128 128 128 128 128 1

Position

Note: What you are seeing here is the latest version of the Data types article, but the position type was different before 1.14.

64-bit value split into three signed integer parts:

  • x: 26 MSBs
  • z: 26 middle bits
  • y: 12 LSBs

For example, a 64-bit position can be broken down as follows:

Example value (big endian): 01000110000001110110001100 10110000010101101101001000 001100111111

  • The red value is the X coordinate, which is 18357644 in this example.
  • The blue value is the Z coordinate, which is -20882616 in this example.
  • The green value is the Y coordinate, which is 831 in this example.

Encoded as follows:

((x & 0x3FFFFFF) << 38) | ((z & 0x3FFFFFF) << 12) | (y & 0xFFF)

And decoded as:

val = read_long();
x = val >> 38;
y = val << 52 >> 52;
z = val << 26 >> 38;

Note: The above assumes that the right shift operator sign extends the value (this is called an arithmetic shift), so that the signedness of the coordinates is preserved. In many languages, this requires the integer type of val to be signed. In the absence of such an operator, the following may be useful:

if x >= 1 << 25 { x -= 1 << 26 }
if y >= 1 << 11 { y -= 1 << 12 }
if z >= 1 << 25 { z -= 1 << 26 }

Fixed-point numbers

Some fields may be stored as fixed-point numbers, where a certain number of bits represents the signed integer part (number to the left of the decimal point) and the rest represents the fractional part (to the right). Floating points (float and double), in contrast, keep the number itself (mantissa) in one chunk, while the location of the decimal point (exponent) is stored beside it.

Essentially, while fixed-point numbers have lower range than floating points, their fractional precision is greater for higher values. This makes them ideal for representing global coordinates of an entity in Minecraft, as it's more important to store the integer part accurately than position them more precisely within a single block (or meter).

Coordinates are often represented as a 32-bit integer, where 5 of the least-significant bits are dedicated to the fractional part, and the rest store the integer part.

Java lacks support for fractional integers directly, but you can represent them as integers. To convert from a double to this integer representation, use the following formulas:

 abs_int = (int) (double * 32.0D);

And back again:

 double = (double) (abs_int / 32.0D);

Bit sets

The types BitSet and Fixed BitSet represent packed lists of bits. The Notchian implementation uses Java's BitSet class.

BitSet

Bit sets of type BitSet are prefixed by their length in longs.

Field Name Field Type Meaning
Length VarInt Number of longs in the following array. May be 0 (if no bits are set).
Data Array of Long A packed representation of the bit set as created by BitSet.toLongArray.

The ith bit is set when (Data[i / 64] & (1 << (i % 64))) != 0, where i starts at 0.

Fixed BitSet

Bit sets of type Fixed BitSet (n) have a fixed length of n bits, encoded as ceil(n / 8) bytes. Note that this is different from BitSet, which uses longs.

Field Name Field Type Meaning
Data Byte Array (n) A packed representation of the bit set as created by BitSet.toByteArray.

The ith bit is set when (Data[i / 8] & (1 << (i % 8))) != 0, where i starts at 0. This encoding is not equivalent to the long array in BitSet.


Other definitions

Term Definition
Player When used in the singular, Player always refers to the client connected to the server.
Entity Entity refers to any item, player, mob, minecart or boat etc. See the Minecraft Wiki article for a full list.
EID An EID — or Entity ID — is a 4-byte sequence used to identify a specific entity. An entity's EID is unique on the entire server.
XYZ In this document, the axis names are the same as those shown in the debug screen (F3). Y points upwards, X points east, and Z points south.
Meter The meter is Minecraft's base unit of length, equal to the length of a vertex of a solid block. The term “block” may be used to mean “meter” or “cubic meter”.
Global palette A table/dictionary/palette mapping nonnegative integers to block states. 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.jar net.minecraft.data.Main --reports. See Data Generators for more information.

Notchian The official implementation of vanilla Minecraft as developed and released by Mojang.

Packet format

Without compression

Field Name Field Type Notes
Length VarInt Length of Packet ID + Data
Packet ID VarInt
Data Byte Array Depends on the connection state and packet ID, see the sections below

With compression

Once a Set Compression packet (with a non-negative threshold) is sent, zlib compression is enabled for all following packets. The format of a packet changes slighty to include the size of the uncompressed packet.

Compressed? Field Name Field Type Notes
No Packet Length VarInt Length of Data Length + compressed length of (Packet ID + Data)
No Data Length VarInt Length of uncompressed (Packet ID + Data) or 0
Yes Packet ID VarInt zlib compressed packet ID (see the sections below)
Data Byte Array zlib compressed packet data (see the sections below)

The length given by the Packet Length field is the number of bytes that remain in that packet, including the Data Length field.

If Data Length is set to zero, then the packet is uncompressed; otherwise it is the size of the uncompressed packet.

If compressed, the uncompressed length of (Packet ID + Data) must be equal to or over the threshold set in the packet Set Compression, otherwise the receiving party will disconnect.

Compression can be disabled by sending the packet Set Compression with a negative Threshold, or not sending the Set Compression packet at all.

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 in Minecraft 1.15.2)
Server Address String (255) 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

Legacy Server List Ping

Warning.png This packet uses a nonstandard format. It is never length-prefixed, and the packet ID is an Unsigned Byte instead of a VarInt.

While not technically part of the current protocol, legacy clients may send this packet to initiate Server List Ping, and modern servers should handle it correctly.

Packet ID State Bound To Field Name Field Type Notes
0xFE Handshaking Server Payload Unsigned Byte always 1 (0x01)

See Server List Ping#1.6 for the details of the protocol that follows this packet.

Status

Main article: Server List Ping

Clientbound

Response

Packet ID State Bound To Field Name Field Type Notes
0x00 Status Client
JSON Response String (32767) See Server List Ping#Response; as with all strings this is prefixed by its length as a VarInt

Pong

Packet ID State Bound To Field Name Field Type Notes
0x01 Status Client Payload Long Should be the same as sent by the client

Serverbound

Request

Packet ID State Bound To Field Name Field Type Notes
0x00 Status Server no fields

Ping

Packet ID State Bound To Field Name Field Type Notes
0x01 Status Server Payload Long May be any number. Notchian clients use a system-dependent time value which is counted in milliseconds.

Login

The login process is as follows:

  1. C→S: Handshake with Next State set to 2 (login)
  2. C→S: Login Start
  3. S→C: Encryption Request
  4. Client auth
  5. C→S: Encryption Response
  6. Server auth, both enable encryption
  7. S→C: Set Compression (optional)
  8. S→C: Login Success

Set Compression, if present, must be sent before Login Success. Note that anything sent after Set Compression must use the Post Compression packet format.

For unauthenticated ("cracked"/offline-mode) and localhost connections (either of the two conditions is enough for an unencrypted connection) there is no encryption. In that case Login Start is directly followed by Login Success.

See Protocol Encryption for details.

Clientbound

Disconnect (login)

Packet ID State Bound To Field Name Field Type Notes
0x00 Login Client Reason Chat

Encryption Request

Packet ID State Bound To Field Name Field Type Notes
0x01 Login Client Server ID String (20) Appears to be empty
Public Key Length VarInt Length of Public Key
Public Key Byte Array
Verify Token Length VarInt Length of Verify Token. Always 4 for Notchian servers.
Verify Token Byte Array A sequence of random bytes generated by the server

See Protocol Encryption for details.

Login Success

Packet ID State Bound To Field Name Field Type Notes
0x02 Login Client UUID String (36) 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.

Warning.png The (notchian) server might take a bit to fully transition to the Play state, so it's recommended to wait before sendings Play packets, either by setting a timeout, or waiting for Play packets from the server (usually Player Info).

The notchian client doesn't send any (non-keep alive) packets until the next tick/time update packet.

Set Compression

Enables compression. If compression is enabled, all following packets are encoded in the compressed packet format. Negative or zero values will disable compression, meaning the packet format should remain in the uncompressed packet format. However, this packet is entirely optional, and if not sent, compression will also not be enabled (the notchian server does not send the packet when compression is disabled).

Packet ID State Bound To Field Name Field Type Notes
0x03 Login Client Threshold VarInt Maximum size of a packet before it is compressed

Login Plugin Request

Used to implement a custom handshaking flow together with Login Plugin Response.

Unlike plugin messages in "play" mode, these messages follow a lock-step request/response scheme, where the client is expected to respond to a request indicating whether it understood. The notchian client always responds that it hasn't understood, and sends an empty payload.

Packet ID State Bound To Field Name Field Type Notes
0x04 Login Client Message ID VarInt Generated by the server - should be unique to the connection.
Channel Identifier Name of the plugin channel used to send the data
Data Byte Array Any data, depending on the channel. The length of this array must be inferred from the packet length.

Serverbound

Login Start

Packet ID State Bound To Field Name Field Type Notes
0x00 Login Server Name String (16) Player's Username

Encryption Response

Packet ID State Bound To Field Name Field Type Notes
0x01 Login Server Shared Secret Length VarInt Length of Shared Secret
Shared Secret Byte Array
Verify Token Length VarInt Length of Verify Token
Verify Token Byte Array

See Protocol Encryption for details.

Login Plugin Response

Packet ID State Bound To Field Name Field Type Notes
0x02 Login Server Message ID VarInt Should match ID from server.
Successful Boolean true if the client understands the request, false otherwise. When false, no payload follows.
Data Optional Byte Array Any data, depending on the channel. The length of this array must be inferred from the packet length.

Play

Clientbound

Spawn Entity

Sent by the server when a vehicle or other non-living entity is created.

Packet ID State Bound To Field Name Field Type Notes
0x00 Play Client Entity ID VarInt EID of the entity
Object UUID UUID
Type VarInt The type of entity (same as in Spawn Living Entity)
X Double
Y Double
Z Double
Pitch Angle
Yaw Angle
Data Int Meaning dependent on the value of the Type field, see Object Data for details.
Velocity X Short Same units as Entity Velocity. Always sent, but only used when Data is greater than 0 (except for some entities which always ignore it; see Object Data for details).
Velocity Y Short
Velocity Z Short

Spawn Experience Orb

Spawns one or more experience orbs.

Packet ID State Bound To Field Name Field Type Notes
0x01 Play Client Entity ID VarInt
X Double
Y Double
Z Double
Count Short The amount of experience this orb will reward once collected

Spawn Weather Entity

With this packet, the server notifies the client of thunderbolts striking within a 512 block radius around the player. The coordinates specify where exactly the thunderbolt strikes.

Packet ID State Bound To Field Name Field Type Notes
0x02 Play Client Entity ID VarInt The EID of the thunderbolt
Type Byte Enum The global entity type, currently always 1 for thunderbolt
X Double
Y Double
Z Double

Spawn Living Entity

Sent by the server when a living entity is spawned.

Packet ID State Bound To Field Name Field Type Notes
0x03 Play Client Entity ID VarInt
Entity UUID UUID
Type VarInt The type of mob. See Entities#Mobs
X Double
Y Double
Z Double
Yaw Angle
Pitch Angle
Head Pitch Angle
Velocity X Short Same units as Entity Velocity
Velocity Y Short Same units as Entity Velocity
Velocity Z Short Same units as Entity Velocity

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 VarInt 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
minecraft:kebab 0 0 0 16 16
minecraft:aztec 1 16 0 16 16
minecraft:alban 2 32 0 16 16
minecraft:aztec2 3 48 0 16 16
minecraft:bomb 4 64 0 16 16
minecraft:plant 5 80 0 16 16
minecraft:wasteland 6 96 0 16 16
minecraft:pool 7 0 32 32 16
minecraft:courbet 8 32 32 32 16
minecraft:sea 9 64 32 32 16
minecraft:sunset 10 96 32 32 16
minecraft:creebet 11 128 32 32 16
minecraft:wanderer 12 0 64 16 32
minecraft:graham 13 16 64 16 32
minecraft:match 14 0 128 32 32
minecraft:bust 15 32 128 32 32
minecraft:stage 16 64 128 32 32
minecraft:void 17 96 128 32 32
skull_and_roses 18 128 128 32 32
minecraft:wither 19 160 128 32 32
minecraft:fighters 20 0 96 64 32
minecraft:pointer 21 0 192 64 64
minecraft:pigscene 22 64 192 64 64
minecraft:burning_skull 23 128 192 64 64
minecraft:skeleton 24 192 64 64 48
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.

Spawn Player

This packet is sent by the server when a player comes into visible range, not when a player joins.

This packet must be sent after the Player Info packet that adds the player data for the client to use when spawning a player. If the Player Info for the player spawned by this packet is not present when this packet arrives, Notchian clients will not spawn the player entity. The Player Info packet includes skin/cape data.

Servers can, however, safely spawn player entities for players not in visible range. The client appears to handle it correctly.

Packet ID State Bound To Field Name Field Type Notes
0x05 Play Client Entity ID VarInt Player's EID
Player UUID UUID See below for notes on offline mode and NPCs
X Double
Y Double
Z Double
Yaw Angle
Pitch Angle

When in online mode, the UUIDs must be valid and have valid skin blobs.

In offline mode, UUID v3 is used with the String OfflinePlayer:<player name>, encoded in UTF-8 (and case-sensitive).

For NPCs UUID v2 should be used. Note:

<+Grum> i will never confirm this as a feature you know that :)

In an example UUID, xxxxxxxx-xxxx-Yxxx-xxxx-xxxxxxxxxxxx, the UUID version is specified by Y. So, for UUID v3, Y will always be 3, and for UUID v2, Y will always be 2.

Entity Animation (clientbound)

Sent whenever an entity should change animation.

Packet ID State Bound To Field Name Field Type Notes
0x06 Play Client Entity ID VarInt Player ID
Animation Unsigned Byte Animation ID (see below)

Animation can be one of the following values:

ID Animation
0 Swing main arm
1 Take damage
2 Leave bed
3 Swing offhand
4 Critical effect
5 Magic critical effect

Statistics

Sent as a response to Client Status 0x04 (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 Category ID Array 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

Acknowledge Player Digging

Packet ID State Bound To Field Name Field Type Notes
0x08 Play Client Location Position Position where the digging was happening
Block VarInt Block state ID of the block that should be at that position now.
Status VarInt enum Same as Player Digging. Only Started digging (0), Cancelled digging (1), and Finished digging (2) are used.
Successful Boolean True if the digging succeeded; false if the client should undo any changes it made locally. (How does this work?)

Block Break Animation

0–9 are the displayable destroy stages and each other number means that there is no animation on this coordinate.

Block break animations can still be applied on air; the animation will remain visible although there is no block being broken. However, if this is applied to a transparent block, odd graphical effects may happen, including water losing its transparency. (An effect similar to this can be seen in normal gameplay when breaking ice blocks)

If you need to display several break animations at the same time you have to give each of them a unique Entity ID. The entity ID does not need to correspond to an actual entity on the client. It is valid to use a randomly generated number.

Packet ID State Bound To Field Name Field Type Notes
0x09 Play Client Entity ID VarInt Entity ID of the entity breaking the block
Location Position Block Position
Destroy Stage Byte 0–9 to set it, any other value to remove it

Block Entity Data

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

Packet ID State Bound To Field Name Field Type Notes
0x0A 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: 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: Unused
  • 11: Declare a bed
  • 12: Set data of a jigsaw block
  • 13: Set items in a campfire
  • 14: Behive information

Block Action

This packet is used for a number of actions and animations performed by blocks, usually non-persistent.

See Block Actions for a list of values.

Warning.png This packet uses a block ID, not a block state. Unfortunately, block IDs are not directly included in the output from Data Generators, but can manually be calculated.

Packet ID State Bound To Field Name Field Type Notes
0x0B Play Client Location Position Block coordinates
Action ID (Byte 1) Unsigned Byte Varies depending on block — see Block Actions
Action Param (Byte 2) Unsigned Byte Varies depending on block — see Block Actions
Block Type VarInt The block type ID for the block. This must match the block at the given coordinates.

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
0x0C Play Client Location Position Block Coordinates
Block ID VarInt The new block state ID for the block as given in the global palette. See that section for more information.

Boss Bar

Packet ID State Bound To Field Name Field Type Notes
0x0D Play Client UUID UUID Unique ID for this bar
Action VarInt Enum Determines the layout of the remaining packet
Action Field Name
0: add Title Chat
Health Float From 0 to 1. Values greater than 1 do not crash a Notchian client, and start rendering part of a second health bar at around 1.5.
Color VarInt Enum Color ID (see below)
Division VarInt Enum Type of division (see below)
Flags Unsigned Byte Bit mask. 0x1: should darken sky, 0x2: is dragon bar (used to play end music), 0x04: create fog (previously was also controlled by 0x02)
1: remove no fields no fields Removes this boss bar
2: update health Health Float as above
3: update title Title Chat
4: update style Color VarInt Enum Color ID (see below)
Dividers VarInt Enum as above
5: update flags Flags Unsigned Byte as above
ID Color
0 Pink
1 Blue
2 Red
3 Green
4 Yellow
5 Purple
6 White
ID Type of division
0 No division
1 6 notches
2 10 notches
3 12 notches
4 20 notches

Server Difficulty

Changes the difficulty setting in the client's option menu

Packet ID State Bound To Field Name Field Type Notes
0x0E Play Client Difficulty Unsigned Byte 0: peaceful, 1: easy, 2: normal, 3: hard
Difficulty locked? Boolean

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).

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 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. 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)

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.

Packet ID State Bound To Field Name Field Type Notes
0x11 Play Client
ID VarInt Transaction ID
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 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 directed graph, 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
0x12 Play Client Count VarInt Number of elements in the following array
Nodes Array of Node An array of nodes
Root index VarInt Index of the root node in the previous array

For more information on this packet, see the Command Data article.

Window Confirmation (clientbound)

A packet from the server indicating whether a request from the client was accepted, or whether there was a conflict (due to lag). If the packet was not accepted, the client must respond with a serverbound window confirmation packet.

Packet ID State Bound To Field Name Field Type Notes
0x13 Play Client Window ID Byte The ID of the window that the action occurred in
Action Number Short Every action that is to be accepted has a unique number. This number is an incrementing integer (starting at 0) with separate counts for each window ID.
Accepted Boolean Whether the action was accepted

Close Window (clientbound)

This packet is sent from the server to the client when a window is forcibly closed, such as when a chest is destroyed while it's open.

Packet ID State Bound To Field Name Field Type Notes
0x14 Play Client Window ID Unsigned Byte This is the ID of the window that was closed. 0 for inventory.

Window Items

The inventory slots

Sent by the server when items in multiple slots (in a window) are added/removed. This includes the main inventory, equipped armour and crafting slots.

Packet ID State Bound To Field Name Field Type Notes
0x15 Play Client Window ID Unsigned Byte The ID of window which items are being sent for. 0 for player inventory.
Count Short Number of elements in the following array
Slot Data Array of Slot

See inventory windows for further information about how slots are indexed.

Window Property

This packet is used to inform the client that part of a GUI window should be updated.

Packet ID State Bound To Field Name Field Type Notes
0x16 Play Client Window ID Unsigned Byte
Property Short The property to be updated, see below
Value Short The new value for the property, see below

The meaning of the Property field depends on the type of the window. The following table shows the known combinations of window type and property, and how the value is to be interpreted.

Window type Property Value
Furnace 0: Fire icon (fuel left) counting from fuel burn time down to 0 (in-game ticks)
1: Maximum fuel burn time fuel burn time or 0 (in-game ticks)
2: Progress arrow counting from 0 to maximum progress (in-game ticks)
3: Maximum progress always 200 on the notchian server
Enchantment Table 0: Level requirement for top enchantment slot The enchantment's xp level requirement
1: Level requirement for middle enchantment slot
2: Level requirement for bottom enchantment slot
3: The enchantment seed Used for drawing the enchantment names (in SGA) clientside. The same seed is used to calculate enchantments, but some of the data isn't sent to the client to prevent easily guessing the entire list (the seed value here is the regular seed bitwise and 0xFFFFFFF0).
4: Enchantment ID shown on mouse hover over top enchantment slot The enchantment id (set to -1 to hide it), see below for values
5: Enchantment ID shown on mouse hover over middle enchantment slot
6: Enchantment ID shown on mouse hover over bottom enchantment slot
7: Enchantment level shown on mouse hover over the top slot The enchantment level (1 = I, 2 = II, 6 = VI, etc.), or -1 if no enchant
8: Enchantment level shown on mouse hover over the middle slot
9: Enchantment level shown on mouse hover over the bottom slot
Beacon 0: Power level 0-4, controls what effect buttons are enabled
1: First potion effect Potion effect ID for the first effect, or -1 if no effect
2: Second potion effect Potion effect ID for the second effect, or -1 if no effect
Anvil 0: Repair cost The repair's cost in xp levels
Brewing Stand 0: Brew time 0 – 400, with 400 making the arrow empty, and 0 making the arrow full
1: Fuel time 0 - 20, with 0 making the arrow empty, and 20 making the arrow full

For an enchanting table, the following numerical IDs are used:

Numerical ID Enchantment ID Enchantment Name
0 minecraft:protection Protection
1 minecraft:fire_protection Fire Protection
2 minecraft:feather_falling Feather Falling
3 minecraft:blast_protection Blast Protection
4 minecraft:projectile_protection Projectile Protection
5 minecraft:respiration Respiration
6 minecraft:aqua_affinity Aqua Affinity
7 minecraft:thorns Thorns
8 minecraft:depth_strider Depth Strider
9 minecraft:frost_walker Frost Walker
10 minecraft:binding_curse Curse of Binding
11 minecraft:sharpness Sharpness
12 minecraft:smite Smite
13 minecraft:bane_of_arthropods Bane of Arthropods
14 minecraft:knockback Knockback
15 minecraft:fire_aspect Fire Aspect
16 minecraft:looting Looting
17 minecraft:sweeping Sweeping Edge
18 minecraft:efficiency Efficiency
19 minecraft:silk_touch Silk Touch
20 minecraft:unbreaking Unbreaking
21 minecraft:fortune Fortune
22 minecraft:power Power
23 minecraft:punch Punch
24 minecraft:flame Flame
25 minecraft:infinity Infinity
26 minecraft:luck_of_the_sea Luck of the Sea
27 minecraft:lure Lure
28 minecraft:loyalty Loyalty
29 minecraft:impaling Impaling
30 minecraft:riptide Riptide
31 minecraft:channeling Channeling
32 minecraft:mending Mending
33 minecraft:vanishing_curse Curse of Vanishing

Set Slot

Sent by the server when an item in a slot (in a window) is added/removed.

Packet ID State Bound To Field Name Field Type Notes
0x17 Play Client Window ID Byte The window which is being updated. 0 for player inventory. Note that all known window types include the player inventory. This packet will only be sent for the currently opened window while the player is performing actions, even if it affects the player inventory. After the window is closed, a number of these packets are sent to update the player's inventory window (0).
Slot Short The slot that should be updated
Slot Data Slot

To set the cursor (the item currently dragged with the mouse), use -1 as Window ID and as Slot.

This packet can only be used to edit the hotbar of the player's inventory if window ID is set to 0 (slots 36 through 44). If the window ID is set to -2, then any slot in the inventory can be used but no add item animation will be played.

Set Cooldown

Applies a cooldown period to all items with the given type. Used by the Notchian server with enderpearls. This packet should be sent when the cooldown starts and also when the cooldown ends (to compensate for lag), although the client will end the cooldown automatically. Can be applied to any item, note that interactions still get sent to the server with the item but the client does not play the animation nor attempt to predict results (i.e block placing).

Packet ID State Bound To Field Name Field Type Notes
0x18 Play Client Item ID VarInt Numeric ID of the item to apply a cooldown to.
Cooldown Ticks VarInt Number of ticks to apply a cooldown for, or 0 to clear the cooldown.

Plugin Message (clientbound)

Main article: Plugin channels

Mods and plugins can use this to send their data. Minecraft itself uses several plugin channels. These internal channels are in the minecraft namespace.

More documentation on this: http://dinnerbone.com/blog/2012/01/13/minecraft-plugin-channels-messaging/

Packet ID State Bound To Field Name Field Type Notes
0x19 Play Client Channel Identifier Name of the plugin channel used to send the data
Data Byte Array Any data, depending on the channel. minecraft: channels are documented here. The length of this array must be inferred from the packet length.

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
0x1A Play Client Sound Name Identifier All sound effect names as of 1.15.2 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

Disconnect (play)

Sent by the server before it disconnects a client. The client assumes that the server has already closed the connection by the time the packet arrives.

Packet ID State Bound To Field Name Field Type Notes
0x1B Play Client Reason Chat Displayed to the client when the connection terminates.

Entity Status

Entity statuses generally trigger an animation for an entity. The available statuses vary by the entity's type (and are available to subclasses of that type as well).

Packet ID State Bound To Field Name Field Type Notes
0x1C Play Client Entity ID Int
Entity Status Byte Enum See below

See Entity statuses for a list of which statuses are valid for each type of entity.

Explosion

Sent when an explosion occurs (creepers, TNT, and ghast fireballs).

Each block in Records is set to air. Coordinates for each axis in record is int(X) + record.x

Packet ID State Bound To Field Name Field Type Notes
0x1D Play Client X Float
Y Float
Z Float
Strength Float A strength greater than or equal to 2.0 spawns a minecraft:explosion_emitter particle, while a lesser strength spawns a minecraft:explosion particle.
Record Count Int Number of elements in the following array
Records Array of (Byte, Byte, Byte) Each record is 3 signed bytes long; the 3 bytes are the XYZ (respectively) signed offsets of affected blocks.
Player Motion X Float X velocity of the player being pushed by the explosion
Player Motion Y Float Y velocity of the player being pushed by the explosion
Player Motion Z Float Z velocity of the player being pushed by the explosion

Unload Chunk

Tells the client to unload a chunk column.

Packet ID State Bound To Field Name Field Type Notes
0x1E Play Client Chunk X Int Block coordinate divided by 16, rounded down
Chunk Z Int Block coordinate divided by 16, rounded down

It is legal to send this packet even if the given chunk is not currently loaded.

Change Game State

Used for a wide variety of game state things, from whether to bed use to gamemode to demo messages.

Packet ID State Bound To Field Name Field Type Notes
0x1F Play Client Reason Unsigned Byte See below
Value Float Depends on Reason

Reason codes:

Reason Effect Value
0 Invalid Bed Would be used to switch between messages, but the only used message is 0 for invalid bed
1 End raining
2 Begin raining
3 Change gamemode 0: Survival, 1: Creative, 2: Adventure, 3: Spectator
4 Exit end 0: Immediately send Client Status of respawn without showing end credits; 1: Show end credits and respawn at the when they finish showing (or when esc is pressed). 1 is sent if the player has not yet received the "The end?" advancement, while if they do have it 0 is used.
5 Demo message 0: Show welcome to demo screen, 101: Tell movement controls, 102: Tell jump control, 103: Tell inventory control, 104: Tell that the demo is over and print a message about how to take a screenshot
6 Arrow hitting player Appears to be played when an arrow strikes another player in Multiplayer
7 Fade value The current darkness value. 1 = Dark, 0 = Bright, Setting the value higher causes the game to change color and freeze
8 Fade time Time in ticks for the sky to fade
9 Play pufferfish sting sound
10 Play elder guardian mob appearance (effect and sound)
11 Enable respawn screen 0: Enable respawn screen, 1: Immediately respawn (sent when the doImmediateRespawn gamerule changes)

Open Horse Window

This packet is used exclusively for opening the horse GUI. Open Window is used for all other GUIs.

Packet ID State Bound To Field Name Field Type Notes
0x20 Play Client Window ID? Byte
Number of slots? VarInt
Entity ID? Integer

Keep Alive (clientbound)

The server will frequently send out a keep-alive, each containing a random ID. The client must respond with the same packet. If the client does not respond to them for over 30 seconds, the server kicks the client. Vice versa, if the server does not send any keep-alives for 20 seconds, the client will disconnect and yields a "Timed out" exception.

The Notchian server uses a system-dependent time in milliseconds to generate the keep alive ID value.

Packet ID State Bound To Field Name Field Type Notes
0x21 Play Client Keep Alive ID Long

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.

Effect

Sent when a client is to play a sound or particle effect.

By default, the Minecraft client adjusts the volume of sound effects based on distance. The final boolean field is used to disable this, and instead the effect is played from 2 blocks away in the correct direction. Currently this is only used for effect 1023 (wither spawn), effect 1028 (enderdragon death), and effect 1038 (end portal opening); it is ignored on other effects.

Packet ID State Bound To Field Name Field Type Notes
0x23 Play Client Effect ID Int The ID of the effect, see below
Location Position The location of the effect
Data Int Extra data for certain effects, see below
Disable Relative Volume Boolean See above

Effect IDs:

ID Name Data
Sound
1000 Dispenser dispenses
1001 Dispenser fails to dispense
1002 Dispenser shoots
1003 Ender eye launched
1004 Firework shot
1005 Iron door opened
1006 Wooden door opened
1007 Wooden trapdoor opened
1008 Fence gate opened
1009 Fire extinguished
1010 Play record Special case, see below for more info
1011 Iron door closed
1012 Wooden door closed
1013 Wooden trapdoor closed
1014 Fence gate closed
1015 Ghast warns
1016 Ghast shoots
1017 Enderdragon shoots
1018 Blaze shoots
1019 Zombie attacks wood door
1020 Zombie attacks iron door
1021 Zombie breaks wood door
1022 Wither breaks block
1023 Wither spawned
1024 Wither shoots
1025 Bat takes off
1026 Zombie infects
1027 Zombie villager converted
1028 Ender dragon death
1029 Anvil destroyed
1030 Anvil used
1031 Anvil landed
1032 Portal travel
1033 Chorus flower grown
1034 Chorus flower died
1035 Brewing stand brewed
1036 Iron trapdoor opened
1037 Iron trapdoor closed
1038 End portal created in overworld
1039 Phantom bites
1040 Zombie converts to drowned
1041 Husk converts to zombie by drowning
1042 Grindstone used
1043 Book page turned
Particle
1500 Composter composts
1501 Lava converts block (either water to stone, or removes existing blocks such as torches)
1502 Redstone torch burns out
1503 Ender eye placed
2000 Spawns 10 smoke particles, e.g. from a fire Direction, see below
2001 Block break + block break sound Block state, as an index into the global palette
2002 Splash potion. Particle effect + glass break sound. Potion ID
2003 Eye of Ender entity break animation — particles and sound
2004 Mob spawn particle effect: smoke + flames
2005 Bonemeal particles How many particles to spawn (if set to 0, 15 are spawned)
2006 Dragon breath
2007 Instant splash potion Potion ID
2008 Ender dragon destroys block
2009 Wet sponge vaporizes in nether
3000 End gateway spawn
3001 Enderdragon growl

Smoke directions:

ID Direction
0 South-East
1 South
2 South-West
3 East
4 (Up or middle ?)
5 West
6 North-East
7 North
8 North-West

Play record: This is actually a special case within this packet. You can start/stop a record at a specific location. Use a valid Record ID to start a record (or overwrite a currently playing one), any other value will stop the record. See Data Generators for information on item IDs.

Particle

Displays the named particle

Packet ID State Bound To Field Name Field Type Notes
0x24 Play Client Particle ID Int The particle ID listed in the particle data type.
Long Distance Boolean If true, particle distance increases from 256 to 65536
X Double X position of the particle
Y Double Y position of the particle
Z Double 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 Varies The variable data listed in the particle data type.

Update Light

Updates light levels for a chunk.

Packet ID State Bound To Field Name Field Type Notes
0x25 Play Client Chunk X VarInt Chunk coordinate (block coordinate divided by 16, rounded down)
Chunk Z VarInt Chunk coordinate (block coordinate divided by 16, rounded down)
Sky Light Mask VarInt Mask containing 18 bits, with the lowest bit corresponding to chunk section -1 (in the void, y=-16 to y=-1) and the highest bit for chunk section 16 (above the world, y=256 to y=271)
Block Light Mask VarInt Mask containing 18 bits, with the same order as sky light
Empty Sky Light Mask VarInt Mask containing 18 bits, which indicates sections that have 0 for all their sky light values. If a section is set in both this mask and the main sky light mask, it is ignored for this mask and it is included in the sky light arrays (the notchian server does not create such masks). If it is only set in this mask, it is not included in the sky light arrays.
Empty Block Light Mask VarInt Mask containing 18 bits, which indicates sections that have 0 for all their block light values. If a section is set in both this mask and the main block light mask, it is ignored for this mask and it is included in the block light arrays (the notchian server does not create such masks). If it is only set in this mask, it is not included in the block light arrays.
Sky Light arrays Length Array VarInt Length of the following array in bytes (always 2048)
Sky Light array Array of 2048 bytes There is 1 array for each bit set to true in the sky light mask, starting with the lowest value. Half a byte per light value.
Block Light arrays Length Array VarInt Length of the following array in bytes (always 2048)
Block Light array Array of 2048 bytes There is 1 array for each bit set to true in the block light mask, starting with the lowest value. Half a byte per light value.

Individual block or sky light arrays are is given for each block with increasing x coordinates, within rows of increasing z coordinates, within layers of increasing y coordinates. Even-indexed items (those with an even x coordinate, starting at 0) are packed into the low bits, odd-indexed into the high bits.

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 Int Enum -1: Nether, 0: Overworld, 1: End; also, note that this is not a VarInt but instead a regular int.
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

Map Data

Updates a rectangular area on a map item.

Packet ID State Bound To Field Name Field Type Notes
0x27 Play Client Map ID VarInt 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 player and item frame icons are shown
Locked Boolean True if the map has been locked in a cartography table
Icon Count VarInt Number of elements in the following array
Icon Type Array VarInt enum See below
X Byte Map coordinates: -128 for furthest left, +127 for furthest right
Z Byte Map coordinates: -128 for highest, +127 for lowest
Direction Byte 0-15
Has Display Name Boolean
Display Name Optional Chat Only present if previous Boolean is true
Columns Unsigned 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

Trade List

The list of trades a villager NPC is offering.

Packet ID State Bound To Field Name Field Type Notes
0x28 Play Client
Window ID VarInt The ID of the window that is open; this is an int rather than a byte.
Size Byte The number of trades in the following array
Trades Input item 1 Array Slot The first item the villager is buying
Output item Slot The item the villager is selling
Has second item Boolean Whether there is a second item
Input item 2 Optional Slot The second item the villager is buying; only present if they have a second item.
Trade disabled Boolean True if the trade is disabled; false if the trade is enabled.
Number of trade uses Integer Number of times the trade has been used so far
Maximum number of trade uses Integer Number of times this trade can be used
XP Integer
Special Price Integer
Price Multiplier Float
Demand Integer
Villager level VarInt Appears on the trade GUI; meaning comes from the translation key merchant.level. + level.

1: Novice, 2: Apprentice, 3: Journeyman, 4: Expert, 5: Master

Experience VarInt Total experience for this villager (always 0 for the wandering trader)
Is regular villager Boolean True if this is a regular villager; false for the wandering trader. When false, hides the villager level and some other GUI elements.
Can restock Boolean True for regular villagers and false for the wandering trader. If true, the "Villagers restock up to two times per day." message is displayed when hovering over disabled trades.
The merchant UI, for reference

Entity Position

This packet is sent by the server when an entity moves less then 8 blocks; if an entity moves more than 8 blocks Entity Teleport should be sent instead.

This packet allows at most 8 blocks movement in any direction, because short range is from -32768 to 32767. And 32768 / (128 * 32) = 8.

Packet ID State Bound To Field Name Field Type Notes
0x29 Play Client Entity ID VarInt
Delta X Short Change in X position as (currentX * 32 - prevX * 32) * 128
Delta Y Short Change in Y position as (currentY * 32 - prevY * 32) * 128
Delta Z Short Change in Z position as (currentZ * 32 - prevZ * 32) * 128
On Ground Boolean

Entity Position and Rotation

This packet is sent by the server when an entity rotates and moves. Since a short range is limited from -32768 to 32767, and movement is offset of fixed-point numbers, this packet allows at most 8 blocks movement in any direction. (-32768 / (32 * 128) == -8)

Packet ID State Bound To Field Name Field Type Notes
0x2A Play Client Entity ID VarInt
Delta X Short Change in X position as (currentX * 32 - prevX * 32) * 128
Delta Y Short Change in Y position as (currentY * 32 - prevY * 32) * 128
Delta Z Short Change in Z position as (currentZ * 32 - prevZ * 32) * 128
Yaw Angle New angle, not a delta
Pitch Angle New angle, not a delta
On Ground Boolean

Entity Rotation

This packet is sent by the server when an entity rotates.

Packet ID State Bound To Field Name Field Type Notes
0x2B Play Client Entity ID VarInt
Yaw Angle New angle, not a delta
Pitch Angle New angle, not a delta
On Ground Boolean

Entity Movement

This packet may be used to initialize an entity.

For player entities, either this packet or any move/look packet is sent every game tick. So the meaning of this packet is basically that the entity did not move/look since the last such packet.

Packet ID State Bound To Field Name Field Type Notes
0x2C Play Client Entity ID VarInt

Vehicle Move (clientbound)

Note that all fields use absolute positioning and do not allow for relative positioning.

Packet ID State Bound To Field Name Field Type Notes
0x2D Play Client X Double Absolute position (X coordinate)
Y Double Absolute position (Y coordinate)
Z Double Absolute position (Z coordinate)
Yaw Float Absolute rotation on the vertical axis, in degrees
Pitch Float Absolute rotation on the horizontal axis, in degrees

Open Book

Sent when a player right clicks with a signed book. This tells the client to open the book GUI.

Packet ID State Bound To Field Name Field Type Notes
0x2E Play Client Hand VarInt enum 0: Main hand, 1: Off hand

Open Window

This is sent to the client when it should open an inventory, such as a chest, workbench, or furnace. This message is not sent anywhere for clients opening their own inventory. For horses, use Open Horse Window.

Packet ID State Bound To Field Name Field Type Notes
0x2F Play Client Window ID VarInt A unique id number for the window to be displayed. Notchian server implementation is a counter, starting at 1.
Window Type VarInt The window type to use for display. Contained in the minecraft:menu regisry; see Inventory for the different values.
Window Title Chat The title of the window

Open Sign Editor

Sent when the client has placed a sign and is allowed to send Update Sign. There must already be a sign at the given location (which the client does not do automatically) - send a Block Change first.

Packet ID State Bound To Field Name Field Type Notes
0x30 Play Client Location Position

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
0x31 Play Client Window ID Byte
Recipe Identifier A recipe ID

Player Abilities (clientbound)

The latter 2 floats are used to indicate the field of view and flying speed respectively, while the first byte is used to determine the value of 4 booleans.

Packet ID State Bound To Field Name Field Type Notes
0x32 Play Client Flags Byte Bit field, see below
Flying Speed Float 0.05 by default
Field of View Modifier Float Modifies the field of view, like a speed potion. A Notchian server will use the same value as the movement speed sent in the Entity Properties packet, which defaults to 0.1 for players.

About the flags:

Field Bit
Invulnerable 0x01
Flying 0x02
Allow Flying 0x04
Creative Mode (Instant Break) 0x08

Combat Event

Originally used for metadata for twitch streaming circa 1.8. Now only used to display the game over screen (with enter combat and end combat completely ignored by the Notchain client)

Packet ID State Bound To Field Name Field Type Notes
0x33 Play Client Event VarInt Enum Determines the layout of the remaining packet
Event Field Name
0: enter combat no fields no fields
1: end combat Duration VarInt Length of the combat in ticks.
Entity ID Int ID of the primary opponent of the ended combat, or -1 if there is no obvious primary opponent.
2: entity dead Player ID VarInt Entity ID of the player that died (should match the client's entity ID).
Entity ID Int The killing entity's ID, or -1 if there is no obvious killer.
Message Chat The death message

Player Info

Sent by the server to update the user list (<tab> in the client).

Packet ID State Bound To Field Name Field Type Notes
0x34 Play Client Action VarInt Determines the rest of the Player format after the UUID
Number Of Players VarInt Number of elements in the following array
Player UUID Array UUID
Action Field Name
0: add player Name String (16)
Number Of Properties VarInt Number of elements in the following array
Property Name Array String (32767)
Value String (32767)
Is Signed Boolean
Signature Optional String (32767) Only if Is Signed is true
Gamemode VarInt
Ping VarInt Measured in milliseconds
Has Display Name Boolean
Display Name Optional Chat Only if Has Display Name is true
1: update gamemode Gamemode VarInt
2: update latency Ping VarInt Measured in milliseconds
3: update display name Has Display Name Boolean
Display Name Optional Chat Only send if Has Display Name is true
4: remove player no fields no fields

The Property field looks as in the response of Mojang API#UUID -> Profile + Skin/Cape, except of course using the protocol format instead of JSON. That is, each player will usually have one property with Name “textures” and Value being a base64-encoded JSON string as documented at Mojang API#UUID -> Profile + Skin/Cape. An empty properties array is also acceptable, and will cause clients to display the player with one of the two default skins depending on UUID.

Ping values correspond with icons in the following way:

  • A ping that negative (i.e. not known to the server yet) will result in the no connection icon.
  • A ping under 150 milliseconds will result in 5 bars
  • A ping under 300 milliseconds will result in 4 bars
  • A ping under 600 milliseconds will result in 3 bars
  • A ping under 1000 milliseconds (1 second) will result in 2 bars
  • A ping greater than or equal to 1 second will result in 1 bar.

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
0x35 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.

Player Position And Look (clientbound)

Updates the player's position on the server. This packet will also close the “Downloading Terrain” screen when joining/respawning.

If the distance between the last known position of the player on the server and the new position set by this packet is greater than 100 meters, the client will be kicked for “You moved too quickly :( (Hacking?)”.

Also if the fixed-point number of X or Z is set greater than 3.2E7D the client will be kicked for “Illegal position”.

Yaw is measured in degrees, and does not follow classical trigonometry rules. The unit circle of yaw on the XZ-plane starts at (0, 1) and turns counterclockwise, with 90 at (-1, 0), 180 at (0, -1) and 270 at (1, 0). Additionally, yaw is not clamped to between 0 and 360 degrees; any number is valid, including negative numbers and numbers greater than 360.

Pitch is measured in degrees, where 0 is looking straight ahead, -90 is looking straight up, and 90 is looking straight down.

Packet ID State Bound To Field Name Field Type Notes
0x36 Play Client X Double Absolute or relative position, depending on Flags
Y Double Absolute or relative position, depending on Flags
Z Double Absolute or relative position, depending on Flags
Yaw Float Absolute or relative rotation on the X axis, in degrees
Pitch Float Absolute or relative rotation on the Y axis, in degrees
Flags Byte Bit field, see below
Teleport ID VarInt Client should confirm this packet with Teleport Confirm containing the same Teleport ID

About the Flags field:

<Dinnerbone> It's a bitfield, X/Y/Z/Y_ROT/X_ROT. If X is set, the x value is relative and not absolute.
Field Bit
X 0x01
Y 0x02
Z 0x04
Y_ROT 0x08
X_ROT 0x10

Unlock Recipes

Packet ID State Bound To Field Name Field Type Notes
0x37 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 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 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.

Destroy Entities

Sent by the server when a list of entities is to be destroyed on the client.

Packet ID State Bound To Field Name Field Type Notes
0x38 Play Client Count VarInt Number of elements in the following array
Entity IDs Array of VarInt The list of entities of destroy

Remove Entity Effect

Packet ID State Bound To Field Name Field Type Notes
0x39 Play Client Entity ID VarInt
Effect ID Byte See this table

Resource Pack Send

Packet ID State Bound To Field Name Field Type Notes
0x3A Play Client URL String (32767) The URL to the resource pack.
Hash String (40) A 40 character hexadecimal and lowercase SHA-1 hash of the resource pack file. (must be lower case in order to work)
If it's not a 40 character hexadecimal string, the client will not use it for hash verification and likely waste bandwidth — but it will still treat it as a unique id

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 -1: The Nether, 0: The Overworld, 1: The End
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

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 Head Look

Changes the direction an entity's head is facing.

While sending the Entity Look packet changes the vertical rotation of the head, sending this packet appears to be necessary to rotate the head horizontally.

Packet ID State Bound To Field Name Field Type Notes
0x3C Play Client Entity ID VarInt
Head Yaw Angle New angle, not a delta

Select Advancement Tab

Sent by the server to indicate that the client should switch advancement tab. Sent either when the client switches tab in the GUI or when an advancement in another tab is made.

Packet ID State Bound To Field Name Field Type Notes
0x3D Play Client Has id Boolean Indicates if the next field is present
Optional Identifier String (32767) See below

The Identifier can be one of the following:

Optional Identifier
minecraft:story/root
minecraft:nether/root
minecraft:end/root
minecraft:adventure/root
minecraft:husbandry/root

If no or an invalid identifier is sent, the client will switch to the first tab in the GUI.

World Border

Packet ID State Bound To Field Name Field Type Notes
0x3E Play Client Action VarInt Enum Determines the format of the rest of the packet
Action Field Name
0: set size Diameter Double Length of a single side of the world border, in meters
1: lerp size Old Diameter Double Current length of a single side of the world border, in meters
New Diameter Double Target length of a single side of the world border, in meters
Speed VarLong Number of real-time milliseconds until New Diameter is reached. It appears that Notchian server does not sync world border speed to game ticks, so it gets out of sync with server lag. If the world border is not moving, this is set to 0.
2: set center X Double
Z Double
3: initialize X Double
Z Double
Old Diameter Double Current length of a single side of the world border, in meters
New Diameter Double Target length of a single side of the world border, in meters
Speed VarLong Number of real-time milliseconds until New Diameter is reached. It appears that Notchian server does not sync world border speed to game ticks, so it gets out of sync with server lag. If the world border is not moving, this is set to 0.
Portal Teleport Boundary VarInt Resulting coordinates from a portal teleport are limited to ±value. Usually 29999984.
Warning Time VarInt In seconds as set by /worldborder warning time
Warning Blocks VarInt In meters
4: set warning time Warning Time VarInt In seconds as set by /worldborder warning time
5: set warning blocks Warning Blocks VarInt In meters

The Notchian client determines how solid to display the warning by comparing to whichever is higher, the warning distance or whichever is lower, the distance from the current diameter to the target diameter or the place the border will be after warningTime seconds. In pseudocode:

distance = max(min(resizeSpeed * 1000 * warningTime, abs(targetDiameter - currentDiameter)), warningDistance);
if (playerDistance < distance) {
    warning = 1.0 - playerDistance / distance;
} else {
    warning = 0.0;
}

Camera

Sets the entity that the player renders from. This is normally used when the player left-clicks an entity while in spectator mode.

The player's camera will move with the entity and look where it is looking. The entity is often another player, but can be any type of entity. The player is unable to move this entity (move packets will act as if they are coming from the other entity).

If the given entity is not loaded by the player, this packet is ignored. To return control to the player, send this packet with their entity ID.

The Notchian server resets this (sends it back to the default entity) whenever the spectated entity is killed or the player sneaks, but only if they were spectating an entity. It also sends this packet whenever the player switches out of spectator mode (even if they weren't spectating an entity).

Packet ID State Bound To Field Name Field Type Notes
0x3F Play Client Camera ID VarInt ID of the entity to set the client's camera to

The notchian also loads certain shaders for given entities:

  • Creeper → shaders/post/creeper.json
  • Spider (and cave spider) → shaders/post/spider.json
  • Enderman → shaders/post/invert.json
  • Anything else → the current shader is unloaded

Held Item Change (clientbound)

Sent to change the player's slot selection.

Packet ID State Bound To Field Name Field Type Notes
0x40 Play Client Slot Byte The slot which the player has selected (0–8)

Update View Position

Huh.png The following information needs to be added to this page:
Why is this even needed? Is there a better name for it? My guess is that it's something to do with logical behavior with latency, but it still seems weird.

Updates the client's location. This is used to determine what chunks should remain loaded and if a chunk load should be ignored; chunks outside of the view distance may be unloaded.

Sent whenever the player moves across a chunk border horizontally, and also (according to testing) for any integer change in the vertical axis, even if it doesn't go across a chunk section border.

Packet ID State Bound To Field Name Field Type Notes
0x41 Play Client Chunk X VarInt Chunk X coordinate of the player's position
Chunk Z VarInt Chunk Z coordinate of the player's position

Update View Distance

Sent by the integrated singleplayer server when changing render distance. Does not appear to be used by the dedicated server, as view-distance in server.properties cannot be changed at runtime.

Packet ID State Bound To Field Name Field Type Notes
0x42 Play Client View Distance VarInt Render distance (2-32)

Display Scoreboard

This is sent to the client when it should display a scoreboard.

Packet ID State Bound To Field Name Field Type Notes
0x43 Play Client Position Byte The position of the scoreboard. 0: list, 1: sidebar, 2: below name, 3 - 18: team specific sidebar, indexed as 3 + team color.
Score Name String (16) The unique name for the scoreboard to be displayed.

Entity Metadata

Updates one or more metadata properties for an existing entity. Any properties not included in the Metadata field are left unchanged.

Packet ID State Bound To Field Name Field Type Notes
0x44 Play Client Entity ID VarInt
Metadata Entity Metadata

Attach Entity

This packet is sent when an entity has been leashed to another entity.

Packet ID State Bound To Field Name Field Type Notes
0x45 Play Client Attached Entity ID Int Attached entity's EID
Holding Entity ID Int ID of the entity holding the lead. Set to -1 to detach.

Entity Velocity

Velocity is believed to be in units of 1/8000 of a block per server tick (50ms); for example, -1343 would move (-1343 / 8000) = −0.167875 blocks per tick (or −3,3575 blocks per second).

Packet ID State Bound To Field Name Field Type Notes
0x46 Play Client Entity ID VarInt
Velocity X Short Velocity on the X axis
Velocity Y Short Velocity on the Y axis
Velocity Z Short Velocity on the Z axis

Entity Equipment

Packet ID State Bound To Field Name Field Type Notes
0x47 Play Client Entity ID VarInt Entity's EID
Slot VarInt Enum Equipment slot. 0: main hand, 1: off hand, 2–5: armor slot (2: boots, 3: leggings, 4: chestplate, 5: helmet)
Item Slot

Set Experience

Sent by the server when the client should change experience levels.

Packet ID State Bound To Field Name Field Type Notes
0x48 Play Client Experience bar Float Between 0 and 1
Level VarInt
Total Experience VarInt See Experience#Leveling up on the Minecraft Wiki for Total Experience to Level conversion

Update Health

Sent by the server to update/set the health of the player it is sent to.

Food saturation acts as a food “overcharge”. Food values will not decrease while the saturation is over zero. Players logging in automatically get a saturation of 5.0. Eating food increases the saturation as well as the food bar.

Packet ID State Bound To Field Name Field Type Notes
0x49 Play Client Health Float 0 or less = dead, 20 = full HP
Food VarInt 0–20
Food Saturation Float Seems to vary from 0.0 to 5.0 in integer increments

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
0x4A 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 Chat Only if mode is 0 or 2. The text to be displayed for the score
Type Optional VarInt enum Only if mode is 0 or 2. 0 = "integer", 1 = "hearts".

Set Passengers

Packet ID State Bound To Field Name Field Type Notes
0x4B Play Client Entity ID VarInt Vehicle's EID
Passenger Count VarInt Number of elements in the following array
Passengers Array of VarInt EIDs of entity's passengers

Teams

Creates and updates teams.

Packet ID State Bound To Field Name Field Type Notes
0x4C 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 Chat
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
Team Color VarInt enum Used to color the name of players on the team; see below
Team Prefix Chat Displayed before the names of players that are part of this team
Team Suffix Chat Displayed after the names of players that are part of this team
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 Chat
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
Team Color VarInt enum Used to color the name of players on the team; see below
Team Prefix Chat Displayed before the names of players that are part of this team
Team Suffix Chat Displayed after the names of players that are part of this team
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.

Team Color: The color of a team defines how the names of the team members are visualized; any formatting code can be used. The following table lists all the possible values.

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

Update Score

This is sent to the client when it should update a scoreboard item.

Packet ID State Bound To Field Name Field Type Notes
0x4D Play Client Entity Name String (40) The entity whose score this is. For players, this is their username; for other entities, it is their UUID.
Action Byte 0 to create/update an item. 1 to remove an item.
Objective Name String (16) The name of the objective the score belongs to
Value Optional VarInt The score to be displayed next to the entry. Only sent when Action does not equal 1.

Spawn Position

Sent by the server after login to specify the coordinates of the spawn point (the point at which players spawn at, and which the compass points to). It can be sent at any time to update the point compasses point at.

Packet ID State Bound To Field Name Field Type Notes
0x4E Play Client Location Position Spawn location

Time Update

Time is based on ticks, where 20 ticks happen every second. There are 24000 ticks in a day, making Minecraft days exactly 20 minutes long.

The time of day is based on the timestamp modulo 24000. 0 is sunrise, 6000 is noon, 12000 is sunset, and 18000 is midnight.

The default SMP server increments the time by 20 every second.

Packet ID State Bound To Field Name Field Type Notes
0x4F Play Client World Age Long In ticks; not changed by server commands
Time of day Long The world (or region) time, in ticks. If negative the sun will stop moving at the Math.abs of the time

Title

Packet ID State Bound To Field Name Field Type Notes
0x50 Play Client Action VarInt Enum
Action Field Name
0: set title Title Text Chat
1: set subtitle Subtitle Text Chat
2: set action bar Action bar text Chat Displays a message above the hotbar (the same as position 2 in Chat Message (clientbound), except that it correctly renders formatted chat. See MC-119145 for more information.)
3: set times and display Fade In Int Ticks to spend fading in
Stay Int Ticks to keep the title displayed
Fade Out Int Ticks to spend out, not when to start fading out
4: hide no fields no fields
5: reset no fields no fields

“Hide” makes the title disappear, but if you run times again the same title will appear. “Reset” erases the text.

The title is visible on screen for Fade In + Stay + Fade Out ticks.

Entity Sound Effect

Plays a sound effect from an entity.

Packet ID State Bound To Field Name Field Type Notes
0x51 Play Client Sound ID VarInt ID of hardcoded sound event (events as of 1.15.2)
Sound Category VarInt Enum The category that this sound will be played from (current categories)
Entity ID VarInt
Volume Float 1.0 is 100%, capped between 0.0 and 1.0 by Notchian clients
Pitch Float Float between 0.5 and 2.0 by Notchian clients

Sound Effect

This packet is used to play a number of hardcoded sound events. For custom sounds, use Named Sound Effect.

Warning.png Numeric sound effect IDs are liable to change between versions

Packet ID State Bound To Field Name Field Type Notes
0x52 Play Client Sound ID VarInt ID of hardcoded sound event (events as of 1.15.2)
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 1.0 is 100%, capped between 0.0 and 1.0 by Notchian clients
Pitch Float Float between 0.5 and 2.0 by Notchian clients

Stop Sound

Packet ID State Bound To Field Name Field Type Notes
0x53 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

Player List Header And Footer

This packet may be used by custom servers to display additional information above/below the player list. It is never sent by the Notchian server.

Packet ID State Bound To Field Name Field Type Notes
0x54 Play Client Header Chat To remove the header, send a empty translatable component: {"translate":""}
Footer Chat To remove the footer, send a empty translatable component: {"translate":""}

NBT Query Response

Sent in response to Query Block NBT or Query Entity NBT.

Packet ID State Bound To Field Name Field Type Notes
0x55 Play Client Transaction ID VarInt Can be compared to the one sent in the original query packet.
NBT NBT Tag The NBT of the block or entity. May be a TAG_END (0) in which case no NBT is present.

Collect Item

Sent by the server when someone picks up an item lying on the ground — its sole purpose appears to be the animation of the item flying towards you. It doesn't destroy the entity in the client memory, and it doesn't add it to your inventory. The server only checks for items to be picked up after each Player Position (and Player Position And Look) packet sent by the client. The collector entity can be any entity; it does not have to be a player. The collected entity also can be any entity, but the Notchian server only uses this for items, experience orbs, and the different varieties of arrows.

Packet ID State Bound To Field Name Field Type Notes
0x56 Play Client Collected Entity ID VarInt
Collector Entity ID VarInt
Pickup Item Count VarInt Seems to be 1 for XP orbs, otherwise the number of items in the stack.

Entity Teleport

This packet is sent by the server when an entity moves more than 8 blocks.

Packet ID State Bound To Field Name Field Type Notes
0x57 Play Client Entity ID VarInt
X Double
Y Double
Z Double
Yaw Angle New angle, not a delta
Pitch Angle New angle, not a delta
On Ground Boolean

Advancements

Packet ID State Bound To Field Name Field Type Notes
0x58 Play Client Reset/Clear Boolean Whether to reset/clear the current advancements
Mapping size VarInt Size of the following array
Advancement mapping Key Array Identifier The identifier of the advancement
Value Advancement See below
List size VarInt Size of the following array
Identifiers Array of Identifier The identifiers of the advancements that should be removed
Progress size VarInt Size of the following array
Progress mapping Key Array Identifier The identifier of the advancement
Value Advancement progress See below

Advancement structure:

Field Name Field Type Notes
Has parent Boolean Indicates whether the next field exists.
Parent id Optional Identifier The identifier of the parent advancement.
Has display Boolean Indicates whether the next field exists
Display data Optional advancement display See below.
Number of criteria VarInt Size of the following array
Criteria Key Array Identifier The identifier of the criterion
Value Void There is no content written here. Perhaps this will be expanded in the future?
Array length VarInt Number of arrays in the following array
Requirements Array length 2 Array VarInt Number of elements in the following array
Requirement Array of String Array of required criteria

Advancement display:

Field Name Field Type Notes
Title Chat
Description Chat
Icon Slot
Frame type VarInt enum 0 = task, 1 = challenge, 2 = goal
Flags Integer 0x1: has background texture; 0x2: show_toast; 0x4: hidden
Background texture Optional Identifier Background texture location. Only if flags indicates it.
X coord Float
Y coord Float

Advancement progress:

Field Name Field Type Notes
Size VarInt Size of the following array
Criteria Criterion identifier Array Identifier The identifier of the criterion.
Criterion progress Criterion progress

Criterion progress:

Field Name Field Type Notes
Achieved Boolean If true, next field is present
Date of achieving Optional Long As returned by Date.getTime

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) 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 20.0 0.0 1024.0 Max Health
generic.followRange 32.0 0.0 2048.0 Follow Range
generic.knockbackResistance 0.0 0.0 1.0 Knockback Resistance
generic.movementSpeed 0.7 0.0 1024.0 Movement Speed
generic.attackDamage 2.0 0.0 2048.0 Attack Damage
generic.attackSpeed 4.0 0.0 1024.0 Attack Speed
generic.flyingSpeed 0.4 0.0 1024.0 Flying Speed
generic.armor 0.0 0.0 30.0 Armor
generic.armorToughness 0.0 0.0 20.0 Armor Toughness
generic.attackKnockback 0.0 0.0 5.0
generic.luck 0.0 -1024.0 1024.0 Luck
horse.jumpStrength 0.7 0.0 2.0 Jump Strength
zombie.spawnReinforcements 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.

Entity Effect

Packet ID State Bound To Field Name Field Type Notes
0x5A Play Client Entity ID VarInt
Effect ID Byte See this table
Amplifier Byte Notchian client displays effect level as Amplifier + 1
Duration VarInt Duration in ticks.
Flags Byte Bit field, see below.

Within flags:

  • 0x01: Is ambient - was the effect spawned from a beacon? All beacon-generated effects are ambient. Ambient effects use a different icon in the HUD (blue border rather than gray). If all effects on an entity are ambient, the "Is potion effect ambient" living metadata field should be set to true. Usually should not be enabled.
  • 0x02: Show particles - should all particles from this effect be hidden? Effects with particles hidden are not included in the calculation of the effect color, and are not rendered on the HUD (but are still rendered within the inventory). Usually should be enabled.
  • 0x04: Show icon - should the icon be displayed on the client? Usually should be enabled.

Declare Recipes

Packet ID State Bound To Field Name Field Type Notes
0x5B 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
crafting_special_mapcloning Recipe for copying maps
crafting_special_mapextending Recipe for adding paper to maps
crafting_special_firework_rocket Recipe for making firework rockets
crafting_special_firework_star Recipe for making firework stars
crafting_special_firework_star_fade Recipe for making firework stars fade between multiple colors
crafting_special_repairitem Recipe for repairing items via crafting
crafting_special_tippedarrow Recipe for crafting tipped arrows
crafting_special_bannerduplicate Recipe for copying banner patterns
crafting_special_banneraddpattern Recipe for adding patterns to banners
crafting_special_shielddecoration Recipe for applying a banner's pattern to a shield
crafting_special_shulkerboxcoloring Recipe for recoloring a shulker box
smelting Smelting recipe As follows:
Name Type Description
Group String Used to group similar recipes together in the recipe book.
Ingredient Ingredient
Result Slot
Experience Float
Cooking time VarInt
blasting Blast furnace recipe
smoking Smoker recipe
campfire_cooking Campfire recipe
stonecutting Stonecutter recipe As follows:
Name Type Description
Group String Used to group similar recipes together in the recipe book. Tag is present in recipe JSON.
Ingredient Ingredient
Result Slot

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

Packet ID State Bound To Field Name Field Type Notes
0x5C Play Client Block Tags (See below) IDs are block IDs
Item Tags (See below) IDs are item IDs
Fluid Tags (See below) IDs are fluid IDs
Entity Tags (See below) IDs are entity 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

Teleport Confirm

Sent by client as confirmation of Player Position And Look.

Packet ID State Bound To Field Name Field Type Notes
0x00 Play Server Teleport ID VarInt The ID given by the Player Position And Look packet

Query Block NBT

Used when Shift+F3+I is pressed while looking at a block.

Packet ID State Bound To Field Name Field Type Notes
0x01 Play Server Transaction ID VarInt An incremental ID so that the client can verify that the response matches.
Location Position The location of the block to check.

Set Difficulty

Must have at least op level 2 to use. Appears to only be used on singleplayer; the difficulty buttons are still disabled in multiplayer.

Packet ID State Bound To Field Name Field Type Notes
0x02 Play Server New difficulty Byte 0: peaceful, 1: easy, 2: normal, 3: hard

Chat Message (serverbound)

Used to send a chat message to the server. The message may not be longer than 256 characters or else the server will kick the client.

If the message starts with a /, the server will attempt to interpret it as a command. Otherwise, the server will broadcast the same chat message to all players on the server (including the player that sent the message), prepended with player's name. Specifically, it will respond with a translate chat component, "chat.type.text" with the first parameter set to the display name of the player (including some chat component logic to support clicking the name to send a PM) and the second parameter set to the message. See processing chat for more information.

Packet ID State Bound To Field Name Field Type Notes
0x03 Play Server Message String (256) The client sends the raw input, not a Chat component

Client Status

Packet ID State Bound To Field Name Field Type Notes
0x04 Play Server Action ID VarInt Enum See below

Action ID values:

Action ID Action Notes
0 Perform respawn Sent when the client is ready to complete login and when the client is ready to respawn after death.
1 Request stats Sent when the client opens the Statistics menu

Client Settings

Sent when the player connects, or when settings are changed.

Packet ID State Bound To Field Name Field Type Notes
0x05 Play Server Locale String (16) e.g. en_GB
View Distance Byte Client-side render distance, in chunks
Chat Mode VarInt Enum 0: enabled, 1: commands only, 2: hidden. See processing chat for more information.
Chat Colors Boolean “Colors” multiplayer setting
Displayed Skin Parts Unsigned Byte Bit mask, see below
Main Hand VarInt Enum 0: Left, 1: Right

Displayed Skin Parts flags:

  • Bit 0 (0x01): Cape enabled
  • Bit 1 (0x02): Jacket enabled
  • Bit 2 (0x04): Left Sleeve enabled
  • Bit 3 (0x08): Right Sleeve enabled
  • Bit 4 (0x10): Left Pants Leg enabled
  • Bit 5 (0x20): Right Pants Leg enabled
  • Bit 6 (0x40): Hat enabled

The most significant bit (bit 7, 0x80) appears to be unused.

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
0x06 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 (32500) All text behind the cursor without the / (e.g. to the left of the cursor in left-to-right languages like English)

Window Confirmation (serverbound)

If a confirmation sent by the client was not accepted, the server will reply with a Window Confirmation (clientbound) packet with the Accepted field set to false. When this happens, the client must send this packet to apologize (as with movement), otherwise the server ignores any successive confirmations.

Packet ID State Bound To Field Name Field Type Notes
0x07 Play Server Window ID Byte The ID of the window that the action occurred in
Action Number Short Every action that is to be accepted has a unique number. This number is an incrementing integer (starting at 1) with separate counts for each window ID.
Accepted Boolean Whether the action was accepted

Click Window Button

Used when clicking on window buttons. Until 1.14, this was only used by enchantment tables.

Packet ID State Bound To Field Name Field Type Notes
0x08 Play Server Window ID Byte The ID of the window sent by Open Window
Button ID Byte Meaning depends on window type; see below
Window type ID Meaning
Enchantment Table 0 Topmost enchantment
1 Middle enchantment
2 Bottom enchantment
Lectern 1 Previous page (which does give a redstone output)
2 Next page
3 Take Book
100+page Opened page number - 100 + number
Stonecutter Recipe button number - 4*row + col. Depends on the item.
Loom Recipe button number - 4*row + col. Depends on the item.

Click Window

This packet is sent by the player when it clicks on a slot in a window.

Packet ID State Bound To Field Name Field Type Notes
0x09 Play Server Window ID Unsigned Byte The ID of the window which was clicked. 0 for player inventory.
Slot Short The clicked slot number, see below
Button Byte The button used in the click, see below
Action Number Short A unique number for the action, implemented by Notchian as a counter, starting at 1 (different counter for every window ID). Used by the server to send back a Confirm Transaction (clientbound).
Mode VarInt Enum Inventory operation mode, see below
Clicked item Slot The clicked slot. Has to be empty (item ID = -1) for drop mode.

See Inventory for further information about how slots are indexed.

When right-clicking on a stack of items, half the stack will be picked up and half left in the slot. If the stack is an odd number, the half left in the slot will be smaller of the amounts.

The distinct type of click performed by the client is determined by the combination of the Mode and Button fields.

Mode Button Slot Trigger
0 0 Normal Left mouse click
1 Normal Right mouse click
1 0 Normal Shift + left mouse click
1 Normal Shift + right mouse click (identical behavior)
2 0 Normal Number key 1
1 Normal Number key 2
2 Normal Number key 3
8 Normal Number key 9
3 2 Normal Middle click, only defined for creative players in non-player inventories.
4 0 Normal* Drop key (Q) (* Clicked item is different, see above)
1 Normal* Ctrl + Drop key (Ctrl-Q) (drops full stack)
0 -999 Left click outside inventory holding nothing (no-op)
1 -999 Right click outside inventory holding nothing (no-op)
5 0 -999 Starting left mouse drag
4 -999 Starting right mouse drag
8 -999 Starting middle mouse drag, only defined for creative players in non-player inventories. (Note: the vanilla client will still incorrectly send this for non-creative players - see MC-46584)
1 Normal Add slot for left-mouse drag
5 Normal Add slot for right-mouse drag
9 Normal Add slot for middle-mouse drag, only defined for creative players in non-player inventories. (Note: the vanilla client will still incorrectly send this for non-creative players - see MC-46584)
2 -999 Ending left mouse drag
6 -999 Ending right mouse drag
10 -999 Ending middle mouse drag, only defined for creative players in non-player inventories. (Note: the vanilla client will still incorrectly send this for non-creative players - see MC-46584)
6 0 Normal Double click

Starting from version 1.5, “painting mode” is available for use in inventory windows. It is done by picking up stack of something (more than 1 item), then holding mouse button (left, right or middle) and dragging held stack over empty (or same type in case of right button) slots. In that case client sends the following to server after mouse button release (omitting first pickup packet which is sent as usual):

  1. packet with mode 5, slot -999, button (0 for left | 4 for right);
  2. packet for every slot painted on, mode is still 5, button (1 | 5);
  3. packet with mode 5, slot -999, button (2 | 6);

If any of the painting packets other than the “progress” ones are sent out of order (for example, a start, some slots, then another start; or a left-click in the middle) the painting status will be reset.

The server will send back a Confirm Transaction packet. If the click was not accepted, the client must send a matching serverbound confirm transaction packet before sending more Click Window packets, otherwise the server will reject them silently. The Notchian server also sends a Window Items packet for the open window and Set Slot packets for the clicked and cursor slot, but only when the click was not accepted, probably to resynchronize client and server.

Close Window (serverbound)

This packet is sent by the client when closing a window.

Notchian clients send a Close Window packet with Window ID 0 to close their inventory even though there is never an Open Window packet for the inventory.

Packet ID State Bound To Field Name Field Type Notes
0x0A Play Server Window ID Unsigned Byte This is the ID of the window that was closed. 0 for player inventory.

Plugin Message (serverbound)

Main article: Plugin channels

Mods and plugins can use this to send their data. Minecraft itself uses some plugin channels. These internal channels are in the minecraft namespace.

More documentation on this: http://dinnerbone.com/blog/2012/01/13/minecraft-plugin-channels-messaging/

Note that the length of Data is known only from the packet length, since the packet has no length field of any kind.

Packet ID State Bound To Field Name Field Type Notes
0x0B Play Server Channel Identifier Name of the plugin channel used to send the data
Data Byte Array Any data, depending on the channel. minecraft: channels are documented here. The length of this array must be inferred from the packet length.

Edit Book

Packet ID State Bound To Field Name Field Type Notes
0x0C Play Server New book Slot
Is signing Boolean True if the player is signing the book; false if the player is saving a draft.
Hand VarInt enum 0: Main hand, 1: Off hand

When editing a draft, the NBT section of the Slot contains this:

TAG_Compound(''): 1 entry
{
  TAG_List('pages'): 2 entries
  {
    TAG_String(0): 'Something on Page 1'
    TAG_String(1): 'Something on Page 2'
  }
}

When signing the book, it instead looks like this:

TAG_Compound(''): 3 entires
{
  TAG_String('author'): 'Steve'
  TAG_String('title'): 'A Wonderful Book'
  TAG_List('pages'): 2 entries
  {
    TAG_String(0): 'Something on Page 1'
    TAG_String(1): 'Something on Page 2'
  }
}

Entity NBT Request

Used when Shift+F3+I is pressed while looking at an entity.

Packet ID State Bound To Field Name Field Type Notes
0x0D Play Server Transaction ID VarInt An incremental ID so that the client can verify that the response matches.
Entity ID VarInt The ID of the entity to query.

Interact Entity

This packet is sent from the client to the server when the client attacks or right-clicks another entity (a player, minecart, etc).

A Notchian server only accepts this packet if the entity being attacked/used is visible without obstruction and within a 4-unit radius of the player's position.

Note that middle-click in creative mode is interpreted by the client and sent as a Creative Inventory Action packet instead.

Packet ID State Bound To Field Name Field Type Notes
0x0E Play Server Entity ID VarInt The ID of the entity to interact
Type VarInt Enum 0: interact, 1: attack, 2: interact at
Target X Optional Float Only if Type is interact at
Target Y Optional Float Only if Type is interact at
Target Z Optional Float Only if Type is interact at
Hand Optional VarInt Enum Only if Type is interact or interact at; 0: main hand, 1: off hand

Keep Alive (serverbound)

The server will frequently send out a keep-alive, each containing a random ID. The client must respond with the same packet.

Packet ID State Bound To Field Name Field Type Notes
0x0F Play Server Keep Alive ID Long

Lock Difficulty

Must have at least op level 2 to use. Appears to only be used on singleplayer; the difficulty buttons are still disabled in multiplayer.

Packet ID State Bound To Field Name Field Type Notes
0x10 Play Server Locked Boolean

Player Position

Updates the player's XYZ position on the server.

Checking for moving too fast is achieved like this:

  • Each server tick, the player's current position is stored
  • When a player moves, the changes in x, y, and z coordinates are compared with the positions from the previous tick (Δx, Δy, Δz)
  • Total movement distance squared is computed as Δx² + Δy² + Δz²
  • The expected movement distance squared is computed as velocityX² + veloctyY² + velocityZ²
  • If the total movement distance squared value minus the expected movement distance squared value is more than 100 (300 if the player is using an elytra), they are moving too fast.

If the player is moving too fast, it will be logged that "<player> moved too quickly! " followed by the change in x, y, and z, and the player will be teleported back to their current (before this packet) serverside position.

Also, if the absolute value of X or the absolute value of Z is a value greater than 3.2×107, or X, Y, or Z are not finite (either positive infinity, negative infinity, or NaN), the client will be kicked for “Invalid move player packet received”.

Packet ID State Bound To Field Name Field Type Notes
0x11 Play Server X Double Absolute position
Feet Y Double Absolute feet position, normally Head Y - 1.62
Z Double Absolute position
On Ground Boolean True if the client is on the ground, false otherwise

Player Position And Rotation (serverbound)

A combination of Player Rotation and Player Position.

Packet ID State Bound To Field Name Field Type Notes
0x12 Play Server X Double Absolute position
Feet Y Double Absolute feet position, normally Head Y - 1.62
Z Double Absolute position
Yaw Float Absolute rotation on the X Axis, in degrees
Pitch Float Absolute rotation on the Y Axis, in degrees
On Ground Boolean True if the client is on the ground, false otherwise

Player Rotation

The unit circle for yaw
The unit circle of yaw, redrawn

Updates the direction the player is looking in.

Yaw is measured in degrees, and does not follow classical trigonometry rules. The unit circle of yaw on the XZ-plane starts at (0, 1) and turns counterclockwise, with 90 at (-1, 0), 180 at (0,-1) and 270 at (1, 0). Additionally, yaw is not clamped to between 0 and 360 degrees; any number is valid, including negative numbers and numbers greater than 360.

Pitch is measured in degrees, where 0 is looking straight ahead, -90 is looking straight up, and 90 is looking straight down.

The yaw and pitch of player (in degrees), standing at point (x0, y0, z0) and looking towards point (x, y, z) can be calculated with:

dx = x-x0
dy = y-y0
dz = z-z0
r = sqrt( dx*dx + dy*dy + dz*dz )
yaw = -atan2(dx,dz)/PI*180
if yaw < 0 then
    yaw = 360 + yaw
pitch = -arcsin(dy/r)/PI*180

You can get a unit vector from a given yaw/pitch via:

x = -cos(pitch) * sin(yaw)
y = -sin(pitch)
z =  cos(pitch) * cos(yaw)
Packet ID State Bound To Field Name Field Type Notes
0x13 Play Server Yaw Float Absolute rotation on the X Axis, in degrees
Pitch Float Absolute rotation on the Y Axis, in degrees
On Ground Boolean True if the client is on the ground, False otherwise

Player Movement

This packet as well as Player Position, Player Look, and Player Position And Look are called the “serverbound movement packets”. Vanilla clients will send Player Position once every 20 ticks even for a stationary player.

This packet is used to indicate whether the player is on ground (walking/swimming), or airborne (jumping/falling).

When dropping from sufficient height, fall damage is applied when this state goes from false to true. The amount of damage applied is based on the point where it last changed from true to false. Note that there are several movement related packets containing this state.

Packet ID State Bound To Field Name Field Type Notes
0x14 Play Server On Ground Boolean True if the client is on the ground, false otherwise

Vehicle Move (serverbound)

Sent when a player moves in a vehicle. Fields are the same as in Player Position And Look. Note that all fields use absolute positioning and do not allow for relative positioning.

Packet ID State Bound To Field Name Field Type Notes
0x15 Play Server X Double Absolute position (X coordinate)
Y Double Absolute position (Y coordinate)
Z Double Absolute position (Z coordinate)
Yaw Float Absolute rotation on the vertical axis, in degrees
Pitch Float Absolute rotation on the horizontal axis, in degrees

Steer Boat

Used to visually update whether boat paddles are turning. The server will update the Boat entity metadata to match the values here.

Packet ID State Bound To Field Name Field Type Notes
0x16 Play Server Left paddle turning Boolean
Right paddle turning Boolean

Right paddle turning is set to true when the left button or forward button is held; left paddle turning is set to true when the right button or forward button is set to true.

Pick Item

Used to swap out an empty space on the hotbar with the item in the given inventory slot. The Notchain client uses this for pick block functionality (middle click) to retrieve items from the inventory.


Packet ID State Bound To Field Name Field Type Notes
0x17 Play Server Slot to use VarInt See Inventory

The server will first search the player's hotbar for an empty slot, starting from the current slot and looping around to the slot before it. If there are no empty slots, it will start a second search from the current slot and find the first slot that does not contain an enchanted item. If there still are no slots that meet that criteria, then the server will use the currently selected slot.

After finding the appropriate slot, the server swaps the items and then send 3 packets:

  • Set Slot, with window ID set to -2 and slot set to the newly chosen slot and the item set to the item that is now in that slot (which was previously at the slot the client requested)
  • Set Slot, with window ID set to -2 and slot set to the slot the player requested, with the item that is now in that slot and was previously on the hotbar slot
  • Held Item Change, with the slot set to the newly chosen slot.

Craft Recipe Request

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
0x18 Play Server Window ID Byte
Recipe Identifier A recipe ID
Make all Boolean Affects the amount of items processed; true if shift is down when clicked

Player Abilities (serverbound)

The latter 2 fields are used to indicate the walking and flying speeds respectively, while the first field is used to determine the value of 4 booleans.

The vanilla client sends this packet when the player starts/stops flying with the Flags parameter changed accordingly. All other parameters are ignored by the vanilla server.

Packet ID State Bound To Field Name Field Type Notes
0x19 Play Server Flags Byte Bit mask. 0x08: damage disabled (god mode), 0x04: can fly, 0x02: is flying, 0x01: is Creative
Flying Speed Float
Walking Speed Float

Player Digging

Sent when the player mines a block. A Notchian server only accepts digging packets with coordinates within a 6-unit radius between the center of the block and 1.5 units from the player's feet (not their eyes).

Packet ID State Bound To Field Name Field Type Notes
0x1A Play Server Status VarInt Enum The action the player is taking against the block (see below)
Location Position Block position
Face Byte Enum The face being hit (see below)

Status can be one of seven values:

Value Meaning Notes
0 Started digging
1 Cancelled digging Sent when the player lets go of the Mine Block key (default: left click)
2 Finished digging Sent when the client thinks it is finished
3 Drop item stack Triggered by using the Drop Item key (default: Q) with the modifier to drop the entire selected stack (default: depends on OS). Location is always set to 0/0/0, Face is always set to -Y.
4 Drop item Triggered by using the Drop Item key (default: Q). Location is always set to 0/0/0, Face is always set to -Y.
5 Shoot arrow / finish eating Indicates that the currently held item should have its state updated such as eating food, pulling back bows, using buckets, etc. Location is always set to 0/0/0, Face is always set to -Y.
6 Swap item in hand Used to swap or assign an item to the second hand. Location is always set to 0/0/0, Face is always set to -Y.

The Face field can be one of the following values, representing the face being hit:

Value Offset Face
0 -Y Bottom
1 +Y Top
2 -Z North
3 +Z South
4 -X West
5 +X East

Entity Action

Sent by the client to indicate that it has performed certain actions: sneaking (crouching), sprinting, exiting a bed, jumping with a horse, and opening a horse's inventory while riding it.

Packet ID State Bound To Field Name Field Type Notes
0x1B Play Server Entity ID VarInt Player ID
Action ID VarInt Enum The ID of the action, see below
Jump Boost VarInt Only used by the “start jump with horse” action, in which case it ranges from 0 to 100. In all other cases it is 0.

Action ID can be one of the following values:

ID Action
0 Start sneaking
1 Stop sneaking
2 Leave bed
3 Start sprinting
4 Stop sprinting
5 Start jump with horse
6 Stop jump with horse
7 Open horse inventory
8 Start flying with elytra

Leave bed is only sent when the “Leave Bed” button is clicked on the sleep GUI, not when waking up due today time.

Open horse inventory is only sent when pressing the inventory key (default: E) while on a horse — all other methods of opening a horse's inventory (involving right-clicking or shift-right-clicking it) do not use this packet.

Steer Vehicle

Packet ID State Bound To Field Name Field Type Notes
0x1C Play Server Sideways Float Positive to the left of the player
Forward Float Positive forward
Flags Unsigned Byte Bit mask. 0x1: jump, 0x2: unmount

Also known as 'Input' packet.

Recipe Book Data

Packet ID State Bound To Field Name Field Type Notes
0x1D Play Server Type VarInt Determines the format of the rest of the packet
Type Field Name
0: Displayed Recipe Recipe ID Identifier A recipe ID
1: Recipe Book States Crafting Recipe Book Open Boolean Whether the player has the crafting recipe book currently opened/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 opened/active.
Smelting Recipe Filter Active Boolean Whether the player has the smelting recipe book filter option currently active.
Blasting Recipe Book Open Boolean May be swapped with smoking recipe book. Also, the notchian client appears to use the same value for both of those books currently.
Blasting Recipe Filter Active Boolean May be swapped with smoking recipe book. Also, the notchian client appears to use the same value for both of those books currently.
Smoking Recipe Book Open Boolean
Smoking Recipe Filter Active Boolean

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

Name Item

Sent as a player is renaming an item in an anvil (each keypress in the anvil UI sends a new Name Item packet). If the new name is empty, then the item loses its custom name (this is different from setting the custom name to the normal name of the item). The item name may be no longer than 35 characters long, and if it is longer than that, then the rename is silently ignored.

Packet ID State Bound To Field Name Field Type Notes
0x1E Play Server Item name String (32767) The new name of the item

Resource Pack Status

Packet ID State Bound To Field Name Field Type Notes
0x1F Play Server Result VarInt Enum 0: successfully loaded, 1: declined, 2: failed download, 3: accepted

Advancement Tab

Packet ID State Bound To Field Name Field Type Notes
0x20 Play Server Action VarInt enum 0: Opened tab, 1: Closed screen
Tab ID Optional identifier Only present if action is Opened tab

Select Trade

When a player selects a specific trade offered by a villager NPC.

Packet ID State Bound To Field Name Field Type Notes
0x21 Play Server Selected slot VarInt The selected slot int the players current (trading) inventory. (Was a full Integer for the plugin message)

Set Beacon Effect

Changes the effect of the current beacon.

Packet ID State Bound To Field Name Field Type Notes
0x22 Play Server Primary Effect VarInt A Potion ID. (Was a full Integer for the plugin message)
Secondary Effect VarInt A Potion ID. (Was a full Integer for the plugin message)

Held Item Change (serverbound)

Sent when the player changes the slot selection

Packet ID State Bound To Field Name Field Type Notes
0x23 Play Server Slot Short The slot which the player has selected (0–8)

Update Command Block

Packet ID State Bound To Field Name Field Type Notes
0x24 Play Server
Location Position
Command String (32767)
Mode VarInt enum One of SEQUENCE (0), AUTO (1), or REDSTONE (2)
Flags Byte 0x01: Track Output (if false, the output of the previous command will not be stored within the command block); 0x02: Is conditional; 0x04: Automatic

Update Command Block Minecart

Packet ID State Bound To Field Name Field Type Notes
0x25 Play Server Entity ID VarInt
Command String
Track Output Boolean If false, the output of the previous command will not be stored within the command block.

Creative Inventory Action

While the user is in the standard inventory (i.e., not a crafting bench) in Creative mode, the player will send this packet.

Clicking in the creative inventory menu is quite different from non-creative inventory management. Picking up an item with the mouse actually deletes the item from the server, and placing an item into a slot or dropping it out of the inventory actually tells the server to create the item from scratch. (This can be verified by clicking an item that you don't mind deleting, then severing the connection to the server; the item will be nowhere to be found when you log back in.) As a result of this implementation strategy, the "Destroy Item" slot is just a client-side implementation detail that means "I don't intend to recreate this item.". Additionally, the long listings of items (by category, etc.) are a client-side interface for choosing which item to create. Picking up an item from such listings sends no packets to the server; only when you put it somewhere does it tell the server to create the item in that location.

This action can be described as "set inventory slot". Picking up an item sets the slot to item ID -1. Placing an item into an inventory slot sets the slot to the specified item. Dropping an item (by clicking outside the window) effectively sets slot -1 to the specified item, which causes the server to spawn the item entity, etc.. All other inventory slots are numbered the same as the non-creative inventory (including slots for the 2x2 crafting menu, even though they aren't visible in the vanilla client).

Packet ID State Bound To Field Name Field Type Notes
0x26 Play Server Slot Short Inventory slot
Clicked Item Slot

Update Jigsaw Block

Sent when Done is pressed on the Jigsaw Block interface.

Packet ID State Bound To Field Name Field Type Notes
0x27 Play Server Location Position Block entity location
Attachment type Identifier
Target pool Identifier
Final state String "Turns into" on the GUI, final_state in NBT

Update Structure Block

Packet ID State Bound To Field Name Field Type Notes
0x28 Play Server
Location Position Block entity location
Action VarInt enum An additional action to perform beyond simply saving the given data; see below
Mode VarInt enum One of SAVE (0), LOAD (1), CORNER (2), DATA (3).
Name String
Offset X Byte Between -32 and 32
Offset Y Byte Between -32 and 32
Offset Z Byte Between -32 and 32
Size X Byte Between 0 and 32
Size Y Byte Between 0 and 32
Size Z Byte Between 0 and 32
Mirror VarInt enum One of NONE (0), LEFT_RIGHT (1), FRONT_BACK (2).
Rotation VarInt enum One of NONE (0), CLOCKWISE_90 (1), CLOCKWISE_180 (2), COUNTERCLOCKWISE_90 (3).
Metadata String
Integrity Float Between 0 and 1
Seed VarLong
Flags Byte 0x01: Ignore entities; 0x02: Show air; 0x04: Show bounding box

Possible actions:

  • 0 - Update data
  • 1 - Save the structure
  • 2 - Load the structure
  • 3 - Detect size

The Notchian client uses update data to indicate no special action should be taken (i.e. the done button).

Update Sign

This message is sent from the client to the server when the “Done” button is pushed after placing a sign.

The server only accepts this packet after Open Sign Editor, otherwise this packet is silently ignored.

Packet ID State Bound To Field Name Field Type Notes
0x29 Play Server Location Position Block Coordinates
Line 1 String (384) First line of text in the sign
Line 2 String (384) Second line of text in the sign
Line 3 String (384) Third line of text in the sign
Line 4 String (384) Fourth line of text in the sign

Animation (serverbound)

Sent when the player's arm swings.

Packet ID State Bound To Field Name Field Type Notes
0x2A Play Server Hand VarInt Enum Hand used for the animation. 0: main hand, 1: off hand.

Spectate

Teleports the player to the given entity. The player must be in spectator mode.

The Notchian client only uses this to teleport to players, but it appears to accept any type of entity. The entity does not need to be in the same dimension as the player; if necessary, the player will be respawned in the right world. If the given entity cannot be found (or isn't loaded), this packet will be ignored. It will also be ignored if the player attempts to teleport to themselves.

Packet ID State Bound To Field Name Field Type Notes
0x2B Play Server Target Player UUID UUID of the player to teleport to (can also be an entity UUID)

Player Block Placement

Packet ID State Bound To Field Name Field Type Notes
0x2C Play Server Hand VarInt Enum The hand from which the block is placed; 0: main hand, 1: off hand
Location Position Block position
Face VarInt Enum The face on which the block is placed (as documented at Player Digging)
Cursor Position X Float The position of the crosshair on the block, from 0 to 1 increasing from west to east
Cursor Position Y Float The position of the crosshair on the block, from 0 to 1 increasing from bottom to top
Cursor Position Z Float The position of the crosshair on the block, from 0 to 1 increasing from north to south
Inside block Boolean True when the player's head is inside of a block.

Upon placing a block, this packet is sent once.

The Cursor Position X/Y/Z fields (also known as in-block coordinates) are calculated using raytracing. The unit corresponds to sixteen pixels in the default resource pack. For example, let's say a slab is being placed against the south face of a full block. The Cursor Position X will be higher if the player was pointing near the right (east) edge of the face, lower if pointing near the left. The Cursor Position Y will be used to determine whether it will appear as a bottom slab (values 0.0–0.5) or as a top slab (values 0.5-1.0). The Cursor Position Z should be 1.0 since the player was looking at the southernmost part of the block.

Inside block is true when a player's head (specifically eyes) are inside of a block's collision. In 1.13 and later versions, collision is rather complicated and individual blocks can have multiple collision boxes. For instance, a ring of vines has a non-colliding hole in the middle. This value is only true when the player is directly in the box. In practice, though, this value is only used by scaffolding to place in front of the player when sneaking inside of it (other blocks will place behind when you intersect with them -- try with glass for instance).

Use Item

Sent when pressing the Use Item key (default: right click) with an item in hand.

Packet ID State Bound To Field Name Field Type Notes
0x2D Play Server Hand VarInt Enum Hand used for the animation. 0: main hand, 1: off hand.