Difference between revisions of "Protocol"

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This page presents a dissection of the current stable [http://minecraft.net/game/ Minecraft Beta] protocol. The current pre-release protocol is documented [[Pre-release_protocol|elsewhere]].  
+
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  |CONTENT = This article is about the protocol for the latest '''stable''' release of Minecraft '''Java Edition''' ([[Protocol version numbers|1.20.4, protocol 765]]). 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]].
 +
}}
  
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]].
+
This page presents a dissection of the current '''[https://minecraft.net/ Minecraft] protocol'''.
  
'''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.
+
If you're having trouble, check out the [[Protocol FAQ|FAQ]] or ask for help in the IRC channel [ircs://irc.libera.chat:6697 #mcdevs on irc.libera.chat] ([https://wiki.vg/MCDevs More Information]).
  
The protocol for Pocket Minecraft is substantially different, and is documented at [[Pocket Minecraft Protocol]].
+
'''Note:''' While you may use the contents of this page without restriction to create servers, clients, bots, etc; substantial reproductions of this page must be attributed IAW [https://creativecommons.org/licenses/by-sa/4.0/ CC BY-SA 4.0].
  
== Data Types ==
+
The changes between versions may be viewed at [[Protocol History]].
  
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.
+
== Definitions ==
  
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 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”.
 +
|-
 +
| Registry
 +
| A table describing static, gameplay-related objects of some kind, such as the types of entities, block states or biomes. The entries of a registry are typically associated with textual or numeric identifiers, or both.
 +
 
 +
Minecraft has a unified registry system used to implement most of the registries, including blocks, items, entities, biomes and dimensions. These "ordinary" registries associate entries with both namespaced textual identifiers (see [[#Identifier]]), and signed (positive) 32-bit numeric identifiers. There is also a registry of registries listing all of the registries in the registry system. Some other registries, most notably the [[Chunk Format#Block state registry|block state registry]], are however implemented in a more ad-hoc fashion.
 +
 
 +
Some registries, such as biomes and dimensions, can be customized at runtime by the server (see [[Registry Data]]), while others, such as blocks, items and entities, are hardcoded. The contents of the hardcoded registries can be extracted via the built-in [[Data Generators]] system.
 +
|-
 +
| Block state
 +
| Each block in Minecraft has 0 or more properties, which in turn may have any number of possible values. These represent, for example, the orientations of blocks, poweredness states of redstone components, and so on. Each of the possible permutations of property values for a block is a distinct block state. The block state registry assigns a numeric identifier to every block state of every block.
 +
 
 +
A current list of properties and state ID ranges is found on [https://pokechu22.github.io/Burger/1.20.4.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.
 +
|-
 +
| Sequence
 +
| The action number counter for local block changes, incremented by one when clicking a block with a hand, right clicking an item, or starting or finishing digging a block. Counter handles latency to avoid applying outdated block changes to the local world.  Also is used to revert ghost blocks created when placing blocks, using buckets, or breaking blocks.
 +
|}
 +
 
 +
== Packet format ==
 +
 
 +
Packets cannot be larger than 2<sup>21</sup> &minus; 1 or 2097151 bytes (the maximum that can be sent in a 3-byte {{Type|VarInt}}). Moreover, the length field must not be longer than 3 bytes, even if the encoded value is within the limit. Unnecessarily long encodings at 3 bytes or below are still allowed.  For compressed packets, this applies to the Packet Length field, i.e. the compressed length.
 +
 
 +
=== Without compression ===
 +
 
 +
{| class="wikitable"
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| Length
 +
| {{Type|VarInt}}
 +
| Length of Packet ID + Data
 +
|-
 +
| Packet ID
 +
| {{Type|VarInt}}
 +
|
 +
|-
 +
| Data
 +
| {{Type|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 slightly to include the size of the uncompressed packet.
 +
 
 +
{| class=wikitable
 +
! Compressed?
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| No
 +
| Packet Length
 +
| {{Type|VarInt}}
 +
| Length of (Data Length) + Compressed length of (Packet ID + Data)
 +
|-
 +
| No
 +
| Data Length
 +
| {{Type|VarInt}}
 +
| Length of uncompressed (Packet ID + Data) or 0
 +
|-
 +
| rowspan="2"| Yes
 +
| Packet ID
 +
| {{Type|VarInt}}
 +
| zlib compressed packet ID (see the sections below)
 +
|-
 +
| Data
 +
| {{Type|Byte Array}}
 +
| zlib compressed packet data (see the sections below)
 +
|}
 +
 
 +
For serverbound packets, the uncompressed length of (Packet ID + Data) must not be greater than 2<sup>23</sup> or 8388608 bytes. Not that a length equal to 2<sup>23</sup> is permitted, which differs from the compressed length limit. The Notchian client, on the other hand, has no limit for the uncompressed length of incoming compressed packets.
 +
 
 +
If the size of the buffer containing the packet data and ID (as a {{Type|VarInt}}) is smaller than the threshold specified in the packet [[#Set Compression|Set Compression]]. It will be sent as uncompressed. This is done by setting the data length as 0. (Comparable to sending a non-compressed format with an extra 0 between the length, and packet data).
 +
 
 +
If it's larger than or equal to the threshold, then it follows the regular compressed protocol format.
 +
 
 +
The Notchian server (but not client) rejects compressed packets smaller than the threshold. Uncompressed packets exceeding the threshold, however, are accepted.
 +
 
 +
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
 +
| {{Type|VarInt}}
 +
| See [[protocol version numbers]] (currently 765 in Minecraft 1.20.4).
 +
|-
 +
| Server Address
 +
| {{Type|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 simple redirect, e.g. if _minecraft._tcp.example.com points to mc.example.org, users connecting to example.com will provide example.org as server address in addition to connecting to it.
 +
|-
 +
| Server Port
 +
| {{Type|Unsigned Short}}
 +
| Default is 25565. The Notchian server does not use this information.
 +
|-
 +
| Next State
 +
| {{Type|VarInt}} {{Type|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 {{Type|Unsigned Byte}} instead of a {{Type|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.
 +
The format of this packet is a remnant of the pre-Netty age, before the switch to Netty in 1.7 brought the standard format that is recognized now. This packet merely exists to inform legacy clients that they can't join our modern server.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0xFE
 +
| Handshaking
 +
| Server
 +
| Payload
 +
| {{Type|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 ===
 +
 
 +
==== Status Response ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="2"| 0x00
 +
| rowspan="2"| Status
 +
| rowspan="2"| Client
 +
|-
 +
| JSON Response
 +
| {{Type|String}} (32767)
 +
| See [[Server List Ping#Status Response]]; as with all strings this is prefixed by its length as a {{Type|VarInt}}.
 +
|}
 +
 
 +
==== Ping Response (status) ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x01
 +
| Status
 +
| Client
 +
| Payload
 +
| {{Type|Long}}
 +
| Should be the same as sent by the client.
 +
|}
 +
 
 +
=== Serverbound ===
 +
 
 +
==== Status Request ====
 +
 
 +
The status can only be requested once immediately after the handshake, before any ping. The server won't respond otherwise.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x00
 +
| Status
 +
| Server
 +
| colspan="3"| ''no fields''
 +
|}
 +
 
 +
==== Ping Request (status) ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x01
 +
| Status
 +
| Server
 +
| Payload
 +
| {{Type|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]]
 +
# C→S: [[#Login Acknowledged|Login Acknowledged]]
 +
 
 +
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 integrated servers (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]]. The Notchian server uses UUID v3 for offline player UUIDs, with the namespace “OfflinePlayer” and the value as the player’s username. For example, Notch’s offline UUID would be derived from the string “OfflinePlayer:Notch”. This is not a requirement however, the UUID may be anything.
 +
 
 +
See [[Protocol Encryption]] for details.
 +
 
 +
=== Clientbound ===
 +
 
 +
==== Disconnect (login) ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x00
 +
| Login
 +
| Client
 +
| Reason
 +
| {{Type|JSON Text Component}}
 +
| The reason why the player was disconnected.
 +
|}
 +
 
 +
==== 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
 +
| {{Type|String}} (20)
 +
| Appears to be empty.
 +
|-
 +
| Public Key Length
 +
| {{Type|VarInt}}
 +
| Length of Public Key.
 +
|-
 +
| Public Key
 +
| {{Type|Byte Array}}
 +
| The server's public key, in bytes.
 +
|-
 +
| Verify Token Length
 +
| {{Type|VarInt}}
 +
| Length of Verify Token. Always 4 for Notchian servers.
 +
|-
 +
| Verify Token
 +
| {{Type|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
 +
! colspan="2"| Field Name
 +
! colspan="2"| Field Type
 +
! Notes
 +
|-
 +
| rowspan="7"| 0x02
 +
| rowspan="7"| Login
 +
| rowspan="7"| Client
 +
| colspan="2"| UUID
 +
| colspan="2"| {{Type|UUID}}
 +
| colspan="2"|
 +
|-
 +
| colspan="2"| Username
 +
| colspan="2"| {{Type|String}} (16)
 +
| colspan="2"|
 +
|-
 +
| colspan="2"| Number Of Properties
 +
| colspan="2"| {{Type|VarInt}}
 +
| Number of elements in the following array.
 +
|-
 +
| rowspan="4"| Property
 +
| Name
 +
| rowspan="4"| {{Type|Array}}
 +
| {{Type|String}} (32767)
 +
| colspan="2"|
 +
|-
 +
| Value
 +
| {{Type|String}} (32767)
 +
| colspan="1"|
 +
|-
 +
| Is Signed
 +
| {{Type|Boolean}}
 +
| colspan="2"|
 +
|-
 +
| Signature
 +
| {{Type|Optional}} {{Type|String}} (32767)
 +
| Only if Is Signed is true.
 +
|}
 +
 
 +
The properties included in this packet are the same as in [[#Player Info Update|Player Info Update]], for the current player.
 +
 
 +
==== Set Compression ====
 +
 
 +
Enables compression.  If compression is enabled, all following packets are encoded in the [[#With compression|compressed packet format]].  Negative 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
 +
|-
 +
| 0x03
 +
| Login
 +
| Client
 +
| Threshold
 +
| {{Type|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
 +
| {{Type|VarInt}}
 +
| Generated by the server - should be unique to the connection.
 +
|-
 +
| Channel
 +
| {{Type|Identifier}}
 +
| Name of the [[plugin channel]] used to send the data.
 +
|-
 +
| Data
 +
| {{Type|Byte Array}} (1048576)
 +
| Any data, depending on the channel. The length of this array must be inferred from the packet length.
 +
|}
 +
 
 +
In Notchian client, the maximum data length is 1048576 bytes.
 +
 
 +
=== Serverbound ===
 +
 
 +
==== Login Start  ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="2"| 0x00
 +
| rowspan="2"| Login
 +
| rowspan="2"| Server
 +
| Name
 +
| {{Type|String}} (16)
 +
| Player's Username.
 +
|-
 +
| Player UUID
 +
| {{Type|UUID}}
 +
| The {{Type|UUID}} of the player logging in. Unused by the Notchian server.
 +
|}
 +
 
 +
==== 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
 +
| {{Type|VarInt}}
 +
| Length of Shared Secret.
 +
|-
 +
| Shared Secret
 +
| {{Type|Byte Array}}
 +
| Shared Secret value, encrypted with the server's public key.
 +
|-
 +
| Verify Token Length
 +
| {{Type|VarInt}}
 +
| Length of Verify Token.
 +
|-
 +
| Verify Token
 +
| {{Type|Byte Array}}
 +
| Verify Token value, encrypted with the same public key as the shared secret.
 +
|}
 +
 
 +
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
 +
| {{Type|VarInt}}
 +
| Should match ID from server.
 +
|-
 +
| Successful
 +
| {{Type|Boolean}}
 +
| <code>true</code> if the client understood the request, <code>false</code> otherwise. When <code>false</code>, no payload follows.
 +
|-
 +
| Data
 +
| {{Type|Optional}} {{Type|Byte Array}} (1048576)
 +
| Any data, depending on the channel. The length of this array must be inferred from the packet length.
 +
|}
 +
 
 +
In Notchian server, the maximum data length is 1048576 bytes.
 +
 
 +
==== Login Acknowledged ====
 +
 
 +
Acknowledgement to the [[Protocol#Login_Success|Login Success]] packet sent by the server.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x03
 +
| Login
 +
| Server
 +
| colspan="3"| ''no fields''
 +
|}
 +
 
 +
This packet switches the connection state to [[#Configuration|configuration]].
 +
 
 +
== Configuration ==
 +
 
 +
=== Clientbound ===
 +
 
 +
==== Clientbound Plugin Message (configuration) ====
 +
 
 +
{{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 information on how it works on [https://dinnerbone.com/blog/2012/01/13/minecraft-plugin-channels-messaging/ Dinnerbone's blog]. More documentation about internal and popular registered channels are [[plugin channel|here]].
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="2"| 0x00
 +
| rowspan="2"| Configuration
 +
| rowspan="2"| Client
 +
| Channel
 +
| {{Type|Identifier}}
 +
| Name of the [[plugin channel]] used to send the data.
 +
|-
 +
| Data
 +
| {{Type|Byte Array}} (1048576)
 +
| Any data. The length of this array must be inferred from the packet length.
 +
|}
 +
 
 +
In Notchian client, the maximum data length is 1048576 bytes.
 +
 
 +
==== Disconnect (configuration) ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x01
 +
| Configuration
 +
| Client
 +
| Reason
 +
| {{Type|Text Component}}
 +
| The reason why the player was disconnected.
 +
|}
 +
 
 +
==== Finish Configuration ====
 +
 
 +
Sent by the server to notify the client that the configuration process has finished. The client answers with [[#Acknowledge_Finish_Configuration|Acknowledge Finish Configuration]] whenever it is ready to continue.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="1"| 0x02
 +
| rowspan="1"| Configuration
 +
| rowspan="1"| Client
 +
| colspan="3"| ''no fields''
 +
|}
 +
 
 +
This packet switches the connection state to [[#Play|play]].
 +
 
 +
==== Clientbound Keep Alive (configuration) ====
 +
 
 +
The server will frequently send out a keep-alive, each containing a random ID. The client must respond with the same payload (see [[#Serverbound Keep Alive (configuration)|Serverbound Keep Alive]]). 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
 +
|-
 +
| 0x03
 +
| Configuration
 +
| Client
 +
| Keep Alive ID
 +
| {{Type|Long}}
 +
|
 +
|}
 +
 
 +
==== Ping (configuration) ====
 +
 
 +
Packet is not used by the Notchian server. When sent to the client, client responds with a [[#Pong (configuration)|Pong]] packet with the same id.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x04
 +
| Configuration
 +
| Client
 +
| ID
 +
| {{Type|Int}}
 +
|
 +
|}
 +
 
 +
==== Registry Data ====
 +
 
 +
Represents certain registries that are sent from the server and are applied on the client.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="1"| 0x05
 +
| rowspan="1"| Configuration
 +
| rowspan="1"| Client
 +
| Registry Codec
 +
| {{Type|NBT}} (Compound)
 +
| See [[Registry Data]].
 +
|}
 +
 
 +
==== Remove Resource Pack (configuration) ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="2"| 0x06
 +
| rowspan="2"| Configuration
 +
| rowspan="2"| Client
 +
| Has UUID
 +
| {{Type|Boolean}}
 +
| Whether a specific resource pack should be removed, or all of them.
 +
|-
 +
| UUID
 +
| {{Type|Optional}} {{Type|UUID}}
 +
| The {{Type|UUID}} of the resource pack to be removed. Only present if the previous field is true.
 +
|}
 +
 
 +
==== Add Resource Pack (configuration) ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="6"| 0x07
 +
| rowspan="6"| Configuration
 +
| rowspan="6"| Client
 +
| UUID
 +
| {{Type|UUID}}
 +
| The unique identifier of the resource pack.
 +
|-
 +
| URL
 +
| {{Type|String}} (32767)
 +
| The URL to the resource pack.
 +
|-
 +
| Hash
 +
| {{Type|String}} (40)
 +
| A 40 character hexadecimal, case-insensitive [[wikipedia:SHA-1|SHA-1]] hash of the resource pack file.<br />If it's not a 40 character hexadecimal string, the client will not use it for hash verification and likely waste bandwidth.
 +
|-
 +
| Forced
 +
| {{Type|Boolean}}
 +
| The Notchian client will be forced to use the resource pack from the server. If they decline they will be kicked from the server.
 +
|-
 +
| Has Prompt Message
 +
| {{Type|Boolean}}
 +
| Whether a custom message should be used on the resource pack prompt.
 +
|-
 +
| Prompt Message
 +
| {{Type|Optional}} {{Type|Text Component}}
 +
| This is shown in the prompt making the client accept or decline the resource pack. Only present if the previous field is true.
 +
|}
 +
 
 +
==== Feature Flags ====
 +
 
 +
Used to enable and disable features, generally experimental ones, on the client.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="2"| 0x08
 +
| rowspan="2"| Configuration
 +
| rowspan="2"| Client
 +
| Total Features
 +
| {{Type|VarInt}}
 +
| Number of features that appear in the array below.
 +
|-
 +
| Feature Flags
 +
| {{Type|Identifier}}
 +
|
 +
|}
 +
 
 +
As of 1.20.4, the following feature flags are available:
 +
 
 +
* minecraft:vanilla - enables vanilla features</li>
 +
* minecraft:bundle - enables support for the bundle</li>
 +
* minecraft:trade_rebalance - enables support for the rebalanced villager trades</li>
 +
* minecraft:update_1_21 - enables support for 1.21 features</li>
 +
 
 +
==== Update Tags (configuration) ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! colspan="2"| Field Name
 +
! colspan="2"| Field Type
 +
! Notes
 +
|-
 +
| rowspan="3"| 0x09
 +
| rowspan="3"| Configuration
 +
| rowspan="3"| Client
 +
| colspan="2"| Length of the array
 +
| colspan="2"| {{Type|VarInt}}
 +
|
 +
|-
 +
| rowspan="2"| Array of tags
 +
| Registry
 +
| rowspan="2"| {{Type|Array}}
 +
| {{Type|Identifier}}
 +
| Registry identifier (Vanilla expects tags for the registries <code>minecraft:block</code>, <code>minecraft:item</code>, <code>minecraft:fluid</code>, <code>minecraft:entity_type</code>, and <code>minecraft:game_event</code>)
 +
|-
 +
| Array of Tag
 +
| (See below)
 +
|
 +
|}
 +
 
 +
Tag arrays look like:
 +
 
 +
{| class="wikitable"
 +
! colspan="2"| Field Name
 +
! colspan="2"| Field Type
 +
! Notes
 +
|-
 +
| colspan="2"| Length
 +
| colspan="2"| {{Type|VarInt}}
 +
| Number of elements in the following array
 +
|-
 +
| rowspan="3"| Tags
 +
| Tag name
 +
| rowspan="3"| {{Type|Array}}
 +
| {{Type|Identifier}}
 +
|
 +
|-
 +
| Count
 +
| {{Type|VarInt}}
 +
| Number of elements in the following array
 +
|-
 +
| Entries
 +
| {{Type|Array}} of {{Type|VarInt}}
 +
| Numeric IDs of the given type (block, item, etc.). This list replaces the previous list of IDs for the given tag. If some preexisting tags are left unmentioned, a warning is printed.
 +
|}
 +
 
 +
See {{Minecraft Wiki|Tag}} on the Minecraft Wiki for more information, including a list of vanilla tags.
 +
 
 +
=== Serverbound ===
 +
 
 +
==== Client Information (configuration) ====
 +
 
 +
Sent when the player connects, or when settings are changed.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="8"| 0x00
 +
| rowspan="8"| Configuration
 +
| rowspan="8"| Server
 +
| Locale
 +
| {{Type|String}} (16)
 +
| e.g. <code>en_GB</code>.
 +
|-
 +
| View Distance
 +
| {{Type|Byte}}
 +
| Client-side render distance, in chunks.
 +
|-
 +
| Chat Mode
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| 0: enabled, 1: commands only, 2: hidden. See [[Chat#Client chat mode]] for more information.
 +
|-
 +
| Chat Colors
 +
| {{Type|Boolean}}
 +
| “Colors” multiplayer setting. Can the chat be colored?
 +
|-
 +
| Displayed Skin Parts
 +
| {{Type|Unsigned Byte}}
 +
| Bit mask, see below.
 +
|-
 +
| Main Hand
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| 0: Left, 1: Right.
 +
|-
 +
| Enable text filtering
 +
| {{Type|Boolean}}
 +
| Enables filtering of text on signs and written book titles. Currently always false (i.e. the filtering is disabled)
 +
|-
 +
| Allow server listings
 +
| {{Type|Boolean}}
 +
| Servers usually list online players, this option should let you not show up in that list.
 +
|}
 +
 
 +
''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.
 +
 
 +
==== Serverbound Plugin Message (configuration) ====
 +
 
 +
{{Main|Plugin channels}}
 +
 
 +
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.
 +
 
 +
More documentation on this: [https://dinnerbone.com/blog/2012/01/13/minecraft-plugin-channels-messaging/ https://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.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="2"| 0x01
 +
| rowspan="2"| Configuration
 +
| rowspan="2"| Server
 +
| Channel
 +
| {{Type|Identifier}}
 +
| Name of the [[plugin channel]] used to send the data.
 +
|-
 +
| Data
 +
| {{Type|Byte Array}} (32767)
 +
| 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.
 +
|}
 +
 
 +
In Notchian server, the maximum data length is 32767 bytes.
 +
 
 +
==== Acknowledge Finish Configuration ====
 +
 
 +
Sent by the client to notify the client that the configuration process has finished. It is sent in response to the server's [[#Finish_Configuration|Finish Configuration]].
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="1"| 0x02
 +
| rowspan="1"| Configuration
 +
| rowspan="1"| Server
 +
| colspan="3"| ''no fields''
 +
|}
 +
 
 +
This packet switches the connection state to [[#Play|play]].
 +
 
 +
==== Serverbound Keep Alive (configuration) ====
 +
 
 +
The server will frequently send out a keep-alive (see [[#Clientbound Keep Alive (configuration)|Clientbound Keep Alive]]), each containing a random ID. The client must respond with the same packet.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x03
 +
| Configuration
 +
| Server
 +
| Keep Alive ID
 +
| {{Type|Long}}
 +
|
 +
|}
 +
 
 +
==== Pong (configuration) ====
 +
 
 +
Response to the clientbound packet ([[#Ping (configuration)|Ping]]) with the same id.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x04
 +
| Configuration
 +
| Server
 +
| ID
 +
| {{Type|Int}}
 +
| id is the same as the ping packet
 +
|}
 +
 
 +
==== Resource Pack Response (configuration) ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="3" | 0x05
 +
| rowspan="3" | Configuration
 +
| rowspan="3" | Server
 +
|-
 +
| UUID
 +
| {{Type|UUID}}
 +
| The unique identifier of the resource pack received in the [[#Add_Resource_Pack_(configuration)|Add Resource Pack (configuration)]] request.
 +
|-
 +
| Result
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| Result ID (see below).
 +
|}
 +
 
 +
Result can be one of the following values:
 +
 
 +
{| class="wikitable"
 +
! ID
 +
! Result
 +
|-
 +
| 0
 +
| Successfully downloaded
 +
|-
 +
| 1
 +
| Declined
 +
|-
 +
| 2
 +
| Failed to download
 +
|-
 +
| 3
 +
| Accepted
 +
|-
 +
| 4
 +
| Downloaded
 +
|-
 +
| 5
 +
| Invalid URL
 +
|-
 +
| 6
 +
| Failed to reload
 +
|-
 +
| 7
 +
| Discarded
 +
|}
 +
 
 +
== Play ==
 +
 
 +
=== Clientbound ===
 +
 
 +
==== Bundle Delimiter ====
 +
 
 +
The delimiter for a bundle of packets. When received, the client should store every subsequent packet it receives, and wait until another delimiter is received. Once that happens, the client is guaranteed to process every packet in the bundle on the same tick, and the client should stop storing packets. For example, this is used to ensure [[#Spawn_Entity|Spawn Entity]] and [[#Set_Entity_Metadata|Set Entity Metadata]] happen on the same tick.
 +
 
 +
The Notchian client doesn't allow more than 4096 packets in the same bundle.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x00
 +
| Play
 +
| Client
 +
| colspan="3"| ''no fields''
 +
|}
 +
 
 +
==== Spawn Entity ====
 +
 
 +
Sent by the server when an entity (aside from [[#Spawn_Experience_Orb|Experince Orb]]) is created.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="13"| 0x01
 +
| rowspan="13"| Play
 +
| rowspan="13"| Client
 +
| Entity ID
 +
| {{Type|VarInt}}
 +
| A unique integer ID mostly used in the protocol to identify the entity.
 +
|-
 +
| Entity UUID
 +
| {{Type|UUID}}
 +
| A unique identifier that is mostly used in persistence and places where the uniqueness matters more.
 +
|-
 +
| Type
 +
| {{Type|VarInt}}
 +
| ID in the <code>minecraft:entity_type</code> registry (see "type" field in [[Entity metadata#Entities]]).
 +
|-
 +
| X
 +
| {{Type|Double}}
 +
|
 +
|-
 +
| Y
 +
| {{Type|Double}}
 +
|
 +
|-
 +
| Z
 +
| {{Type|Double}}
 +
|
 +
|-
 +
| Pitch
 +
| {{Type|Angle}}
 +
| To get the real pitch, you must divide this by (256.0F / 360.0F)
 +
|-
 +
| Yaw
 +
| {{Type|Angle}}
 +
| To get the real yaw, you must divide this by (256.0F / 360.0F)
 +
|-
 +
| Head Yaw
 +
| {{Type|Angle}}
 +
| Only used by living entities, where the head of the entity may differ from the general body rotation.
 +
|-
 +
| Data
 +
| {{Type|VarInt}}
 +
| Meaning dependent on the value of the Type field, see [[Object Data]] for details.
 +
|-
 +
| Velocity X
 +
| {{Type|Short}}
 +
| rowspan="3"| Same units as [[#Set Entity Velocity|Set Entity Velocity]].
 +
|-
 +
| Velocity Y
 +
| {{Type|Short}}
 +
|-
 +
| Velocity Z
 +
| {{Type|Short}}
 +
|}
 +
 
 +
{{Warning2|The points listed below should be considered when this packet is used to spawn a player entity.}}
 +
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). The Notchian server uses <code>UUID.nameUUIDFromBytes</code>, implemented by OpenJDK [https://github.com/AdoptOpenJDK/openjdk-jdk8u/blob/9a91972c76ddda5c1ce28b50ca38cbd8a30b7a72/jdk/src/share/classes/java/util/UUID.java#L153-L175 here].
 +
 
 +
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>.
 +
 
 +
==== Spawn Experience Orb ====
 +
 
 +
Spawns one or more experience orbs.
  
 
{| 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="5"| 0x02
| class="col2" | -128 to 127
+
| rowspan="5"| Play
| class="col3" | Signed, two's complement
+
| rowspan="5"| Client
|- class="row2"
+
| Entity ID
! class="col0 centeralign" | short
+
| {{Type|VarInt}}
| class="col1 centeralign" | 2
+
|
| class="col2" | -32768 to 32767
+
|-
| class="col3" | Signed, two's complement
+
| X
|- class="row3"
+
| {{Type|Double}}
! class="col0 centeralign" | int
+
|
| class="col1 centeralign" | 4
+
|-
| class="col2" | -2147483648 to 2147483647
+
| Y
| class="col3" | Signed, two's complement
+
| {{Type|Double}}
|- class="row4"
+
|
! class="col0 centeralign" | long
+
|-
| class="col1 centeralign" | 8
+
| Z
| class="col2" | -9223372036854775808 to 9223372036854775807
+
| {{Type|Double}}
| class="col3" | Signed, two's complement
+
|
|- class="row5"
+
|-
! class="col0 centeralign" | float
+
| Count
| class="col1 centeralign" | 4
+
| {{Type|Short}}
| class="col2" |
+
| The amount of experience this orb will reward once collected.
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
 
|- class="row6"
 
! class="col0 centeralign" | double
 
| class="col1 centeralign" | 8
 
| class="col2" |
 
See [http://java.sun.com/docs/books/jls/third_edition/html/typesValues.html#4.2.3 this]
 
| class="col3" | Double-precision 64-bit IEEE 754 floating point
 
|- class="row7"
 
! class="col0 centeralign" | string
 
| class="col1 centeralign" | ≥ 2 <br />≤ 240
 
| class="col2" | N/A
 
| class="col3" | [http://en.wikipedia.org/wiki/UTF-16/UCS-2 UCS-2] string, big-endian. Prefixed by a short containing the length of the string in characters. UCS-2 consists of 16-bit words, each of which represent a Unicode code point between U+0000 and U+FFFF inclusive.
 
|- class="row8"
 
! class="col0 centeralign" | bool
 
| class="col1 centeralign" | 1
 
| class="col2" | 0 or 1
 
| class="col3" | Value can be either True (0x01) or False (0x00)
 
|- class="row9"
 
! class="col0 centeralign" | metadata
 
| class="col1 centeralign" | Varies
 
| class="col2" | See [[Entities#Entity_Metadata_Format|this]]
 
| class="Col3" |
 
|}
 
  
== Terminology ==
+
==== Entity Animation ====
  
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.
+
Sent whenever an entity should change animation.
  
 
{| 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"| 0x03
| class="col1" | Entity refers to any item, player, mob, minecart or boat 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
+
| Entity ID
| class="col1" | An EID - or Entity ID - is a unique 4-byte integer used to identify a specific entity
+
| {{Type|VarInt}}
|- class="row4"
+
| Player ID.
! 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.
+
| Animation
|}
+
| {{Type|Unsigned Byte}}
 +
| Animation ID (see below).
 +
|}
  
== Units of Measurement ==
+
Animation can be one of the following values:
  
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"
 +
! ID
 +
! Animation
 +
|-
 +
| 0
 +
| Swing main arm
 +
|-
 +
| 2
 +
| Leave bed
 +
|-
 +
| 3
 +
| Swing offhand
 +
|-
 +
| 4
 +
| Critical effect
 +
|-
 +
| 5
 +
| Magic critical effect
 +
|}
  
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.
+
==== Award Statistics ====
 +
 
 +
Sent as a response to [[#Client Command|Client Command]] (id 1). Will only send the changed values if previously requested.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
| class="col0" |
+
! State
! class="col1 centeralign" | Data Types
+
! Bound To
! class="col2 centeralign" | Units
+
! colspan="2"| Field Name
! class="col3" | Represents
+
! colspan="2"| Field Type
|- class="row1"
+
! Notes
! class="col0" | Absolute
+
|-
| class="col1 centeralign" | double
+
| rowspan="4"| 0x04
| class="col2 centeralign" | meters
+
| rowspan="4"| Play
| class="col3" | Represents an object's location in the world.
+
| rowspan="4"| Client
|- class="row2"
+
| colspan="2"| Count
! class="col0" | Absolute Integer
+
| colspan="2"| {{Type|VarInt}}
| class="col1 centeralign" | int
+
| Number of elements in the following array.
| 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>
+
| rowspan="3"| Statistic
|- class="row3"
+
| Category ID
! class="col0" | Block
+
| rowspan="3"| {{Type|Array}}
| class="col1 centeralign" | byte, short, int
+
| {{Type|VarInt}}
| class="col2 centeralign" | meters
+
| See below.
| class="col3" | Represents a block's location in the world.
+
|-
|- class="row4"
+
| Statistic ID
! class="col0" | Chunk
+
| {{Type|VarInt}}
| class="col1 centeralign" | short, int
+
| See below.
| class="col2 centeralign" | chunks
+
|-
| class="col3" | Represents the position of a chunk.
+
| Value
|}
+
| {{Type|VarInt}}
 +
| The amount to set it to.
 +
|}
  
== Packets ==
+
Categories (these are namespaced, but with <code>:</code> replaced with <code>.</code>):
  
All packets begin with a single "Packet ID" byteListed packet size includes this bytePackets are either "server to client", "client to server", or bothIf not specified, assume that the packet can be sent both waysThere is no "length" field; for variable length packets, you must parse to the end to determine the length.
+
{| 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
 +
|}
  
=== Keep Alive (0x00) ===
+
Blocks, Items, and Entities use block (not block state), item, and entity ids.
  
The server will frequently send out a keep-alive, each containing a random ID. The client must respond with the same packet.
+
Custom has the following (unit only matters for clients):
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. The client may send packets with Keep-alive ID=0.
 
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Name
! class="col0" | Packet ID
+
! ID
! class="col1" | Field Name
+
! Unit
! class="col2" | Field Type
+
|-
! class="col3" | Example
+
| <code>minecraft.leave_game</code>
! class="col4" | Notes
+
| 0
|- class="row1"
+
| None
| class="col0 centeralign" | 0x00
+
|-
| class="col1 centeralign" | Keep-alive ID
+
| <code>minecraft.play_one_minute</code>
| class="col2 centeralign" | int
+
| 1
| class="col3 centeralign" | <code>957759560</code>
+
| Time
| class="col4" | Server-generated random id
+
|-
|- class="row2"
+
| <code>minecraft.time_since_death</code>
! class="col0" | Total Size:
+
| 2
| class="col1 rightalign" colspan="4" | 5 bytes
+
| Time
|}
+
|-
 +
| <code>minecraft.time_since_rest</code>
 +
| 3
 +
| Time
 +
|-
 +
| <code>minecraft.sneak_time</code>
 +
| 4
 +
| Time
 +
|-
 +
| <code>minecraft.walk_one_cm</code>
 +
| 5
 +
| Distance
 +
|-
 +
| <code>minecraft.crouch_one_cm</code>
 +
| 6
 +
| Distance
 +
|-
 +
| <code>minecraft.sprint_one_cm</code>
 +
| 7
 +
| Distance
 +
|-
 +
| <code>minecraft.walk_on_water_one_cm</code>
 +
| 8
 +
| Distance
 +
|-
 +
| <code>minecraft.fall_one_cm</code>
 +
| 9
 +
| Distance
 +
|-
 +
| <code>minecraft.climb_one_cm</code>
 +
| 10
 +
| Distance
 +
|-
 +
| <code>minecraft.fly_one_cm</code>
 +
| 11
 +
| Distance
 +
|-
 +
| <code>minecraft.walk_under_water_one_cm</code>
 +
| 12
 +
| Distance
 +
|-
 +
| <code>minecraft.minecart_one_cm</code>
 +
| 13
 +
| Distance
 +
|-
 +
| <code>minecraft.boat_one_cm</code>
 +
| 14
 +
| Distance
 +
|-
 +
| <code>minecraft.pig_one_cm</code>
 +
| 15
 +
| Distance
 +
|-
 +
| <code>minecraft.horse_one_cm</code>
 +
| 16
 +
| Distance
 +
|-
 +
| <code>minecraft.aviate_one_cm</code>
 +
| 17
 +
| Distance
 +
|-
 +
| <code>minecraft.swim_one_cm</code>
 +
| 18
 +
| Distance
 +
|-
 +
| <code>minecraft.strider_one_cm</code>
 +
| 19
 +
| Distance
 +
|-
 +
| <code>minecraft.jump</code>
 +
| 20
 +
| None
 +
|-
 +
| <code>minecraft.drop</code>
 +
| 21
 +
| None
 +
|-
 +
| <code>minecraft.damage_dealt</code>
 +
| 22
 +
| Damage
 +
|-
 +
| <code>minecraft.damage_dealt_absorbed</code>
 +
| 23
 +
| Damage
 +
|-
 +
| <code>minecraft.damage_dealt_resisted</code>
 +
| 24
 +
| Damage
 +
|-
 +
| <code>minecraft.damage_taken</code>
 +
| 25
 +
| Damage
 +
|-
 +
| <code>minecraft.damage_blocked_by_shield</code>
 +
| 26
 +
| Damage
 +
|-
 +
| <code>minecraft.damage_absorbed</code>
 +
| 27
 +
| Damage
 +
|-
 +
| <code>minecraft.damage_resisted</code>
 +
| 28
 +
| Damage
 +
|-
 +
| <code>minecraft.deaths</code>
 +
| 29
 +
| None
 +
|-
 +
| <code>minecraft.mob_kills</code>
 +
| 30
 +
| None
 +
|-
 +
| <code>minecraft.animals_bred</code>
 +
| 31
 +
| None
 +
|-
 +
| <code>minecraft.player_kills</code>
 +
| 32
 +
| None
 +
|-
 +
| <code>minecraft.fish_caught</code>
 +
| 33
 +
| None
 +
|-
 +
| <code>minecraft.talked_to_villager</code>
 +
| 34
 +
| None
 +
|-
 +
| <code>minecraft.traded_with_villager</code>
 +
| 35
 +
| None
 +
|-
 +
| <code>minecraft.eat_cake_slice</code>
 +
| 36
 +
| None
 +
|-
 +
| <code>minecraft.fill_cauldron</code>
 +
| 37
 +
| None
 +
|-
 +
| <code>minecraft.use_cauldron</code>
 +
| 38
 +
| None
 +
|-
 +
| <code>minecraft.clean_armor</code>
 +
| 39
 +
| None
 +
|-
 +
| <code>minecraft.clean_banner</code>
 +
| 40
 +
| None
 +
|-
 +
| <code>minecraft.clean_shulker_box</code>
 +
| 41
 +
| None
 +
|-
 +
| <code>minecraft.interact_with_brewingstand</code>
 +
| 42
 +
| None
 +
|-
 +
| <code>minecraft.interact_with_beacon</code>
 +
| 43
 +
| None
 +
|-
 +
| <code>minecraft.inspect_dropper</code>
 +
| 44
 +
| None
 +
|-
 +
| <code>minecraft.inspect_hopper</code>
 +
| 45
 +
| None
 +
|-
 +
| <code>minecraft.inspect_dispenser</code>
 +
| 46
 +
| None
 +
|-
 +
| <code>minecraft.play_noteblock</code>
 +
| 47
 +
| None
 +
|-
 +
| <code>minecraft.tune_noteblock</code>
 +
| 48
 +
| None
 +
|-
 +
| <code>minecraft.pot_flower</code>
 +
| 49
 +
| None
 +
|-
 +
| <code>minecraft.trigger_trapped_chest</code>
 +
| 50
 +
| None
 +
|-
 +
| <code>minecraft.open_enderchest</code>
 +
| 51
 +
| None
 +
|-
 +
| <code>minecraft.enchant_item</code>
 +
| 52
 +
| None
 +
|-
 +
| <code>minecraft.play_record</code>
 +
| 53
 +
| None
 +
|-
 +
| <code>minecraft.interact_with_furnace</code>
 +
| 54
 +
| None
 +
|-
 +
| <code>minecraft.interact_with_crafting_table</code>
 +
| 55
 +
| None
 +
|-
 +
| <code>minecraft.open_chest</code>
 +
| 56
 +
| None
 +
|-
 +
| <code>minecraft.sleep_in_bed</code>
 +
| 57
 +
| None
 +
|-
 +
| <code>minecraft.open_shulker_box</code>
 +
| 58
 +
| None
 +
|-
 +
| <code>minecraft.open_barrel</code>
 +
| 59
 +
| None
 +
|-
 +
| <code>minecraft.interact_with_blast_furnace</code>
 +
| 60
 +
| None
 +
|-
 +
| <code>minecraft.interact_with_smoker</code>
 +
| 61
 +
| None
 +
|-
 +
| <code>minecraft.interact_with_lectern</code>
 +
| 62
 +
| None
 +
|-
 +
| <code>minecraft.interact_with_campfire</code>
 +
| 63
 +
| None
 +
|-
 +
| <code>minecraft.interact_with_cartography_table</code>
 +
| 64
 +
| None
 +
|-
 +
| <code>minecraft.interact_with_loom</code>
 +
| 65
 +
| None
 +
|-
 +
| <code>minecraft.interact_with_stonecutter</code>
 +
| 66
 +
| None
 +
|-
 +
| <code>minecraft.bell_ring</code>
 +
| 67
 +
| None
 +
|-
 +
| <code>minecraft.raid_trigger</code>
 +
| 68
 +
| None
 +
|-
 +
| <code>minecraft.raid_win</code>
 +
| 69
 +
| None
 +
|-
 +
| <code>minecraft.interact_with_anvil</code>
 +
| 70
 +
| None
 +
|-
 +
| <code>minecraft.interact_with_grindstone</code>
 +
| 71
 +
| None
 +
|-
 +
| <code>minecraft.target_hit</code>
 +
| 72
 +
| None
 +
|-
 +
| <code>minecraft.interact_with_smithing_table</code>
 +
| 73
 +
| None
 +
|}
 +
 
 +
Units:
  
=== Login Request (0x01) ===
+
* 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
  
==== Client to Server ====
+
==== Acknowledge Block Change ====
  
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.
+
Acknowledges a user-initiated block change. After receiving this packet, the client will display the block state sent by the server instead of the one predicted by 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="9" | 0x01
+
| rowspan="1"| 0x05
| class="col1 centeralign" | Protocol Version
+
| rowspan="1"| Play
| class="col2 centeralign" | int
+
| rowspan="1"| Client
| class="col3 centeralign" | <code>20</code>
+
| Sequence ID
| class="col4" | 1.1's protocol version is <code>23</code>
+
| {{Type|VarInt}}
|- class="row2"
+
| Represents the sequence to acknowledge, this is used for properly syncing block changes to the client after interactions.
| class="col0 centeralign" | Username
+
|}
| class="col1 centeralign" | string
+
 
| class="col2 centeralign" | <code>TkTech</code>
+
==== Set Block Destroy Stage ====
| class="col3" | The name of the user attempting to login, max length of 16
 
|- class="row3"
 
| class="col0 centeralign" | Not used
 
| class="col1 centeralign" | string
 
| class="col2 centeralign" | (empty string)
 
| class="col3" |
 
|- class="row4"
 
| class="col0 centeralign" | Not used
 
| class="col1 centeralign" | int
 
| class="col2 centeralign" | <code>0</code>
 
| class="col3" |
 
|- class="row5"
 
| class="col0 centeralign" | Not used
 
| class="col1 centeralign" | int
 
| class="col2 centeralign" | <code>0</code>
 
| class="col3" |
 
|- class="row6"
 
| class="col0 centeralign" | Not used
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>0</code>
 
| class="col3" |
 
|- class="row7"
 
| class="col0 centeralign" | Not used
 
| class="col1 centeralign" | unsigned byte
 
| class="col2 centeralign" | <code>0</code>
 
| class="col3" |
 
|- class="row8"
 
| class="col0 centeralign" | Not used
 
| class="col1 centeralign" | unsigned byte
 
| class="col2 centeralign" | <code>0</code>
 
| class="col3" |
 
|- class="row9"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 20 bytes + length of strings
 
|}
 
  
==== Server to Client ====
+
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"| 0x06
 +
| rowspan="3"| Play
 +
| rowspan="3"| Client
 +
| Entity ID
 +
| {{Type|VarInt}}
 +
| The ID of the entity breaking the block.
 +
|-
 +
| Location
 +
| {{Type|Position}}
 +
| Block Position.
 +
|-
 +
| Destroy Stage
 +
| {{Type|Byte}}
 +
| 0–9 to set it, any other value to remove it.
 +
|}
  
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.
+
==== Block Entity Data ====
  
Max players is used by the client to draw the player list. Setting this value lower than the actual max players, or indeed the number of players online, will only affect the size and number of users displayed. Values above 127 will cause the player list not to be drawn. Values above 60 will cause usernames to overlap and not fit in their bounding boxes.
+
Sets the block entity associated with the block at the given location.
  
 
{| 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="9" | 0x01
+
| rowspan="3"| 0x07
| class="col1 centeralign" | Entity ID
+
| rowspan="3"| Play
| class="col2 centeralign" | int
+
| rowspan="3"| Client
| class="col3 centeralign" | <code>1298</code>
+
| Location
| class="col4" | The Players Entity ID
+
| {{Type|Position}}
|- class="row2"
+
|
| class="col0 centeralign" | Not used
+
|-
| class="col1 centeralign" | string
+
| Type
| class="col2 centeralign" | (empty string)
+
| {{Type|VarInt}}
| class="col3" | Not used
+
| The type of the block entity
|- class="row3"
+
|-
| class="col0 centeralign" | Level Type
+
| NBT Data
| class="col1 centeralign" | string
+
| {{Type|NBT}}
| class="col2 centeralign" | DEFAULT
+
| 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).
| class="col3" | DEFAULT or SUPERFLAT; level-type in server.properties
+
|}
|- class="row4"
 
| class="col0 centeralign" | Server mode
 
| class="col1 centeralign" | int
 
| class="col2 centeralign" | <code>0</code>
 
| class="col3" | 0 for survival, 1 for creative
 
|- class="row5"
 
| class="col0 centeralign" | Dimension
 
| class="col1 centeralign" | int
 
| class="col2 centeralign" | <code>0</code>
 
| class="col3" | <code>-1</code>: The Nether, <code>0</code>: The Overworld, <code>1</code>: The End
 
|- class="row7"
 
| class="col0 centeralign" | Difficulty
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>1</code>
 
| class="col3" | <code>0</code> thru <code>3</code> for Peaceful, Easy, Normal, Hard
 
|- class="row6"
 
| class="col0 centeralign" | World height
 
| class="col1 centeralign" | unsigned byte
 
| class="col2 centeralign" | <code>128</code>
 
| class="col3" | Defaults to <code>128</code>
 
|- class="row7"
 
| class="col0 centeralign" | Max players
 
| class="col1 centeralign" | unsigned byte
 
| class="col2 centeralign" | <code>8</code>
 
| class="col3" | Used by the client to draw the player list
 
|- class="row8"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 20 bytes + length of strings
 
|}
 
  
=== Handshake (0x02) ===
+
==== Block Action ====
  
==== Client to Server ====
+
This packet is used for a number of actions and animations performed by blocks, usually non-persistent.  The client ignores the provided block type and instead uses the block state in their world.
  
This is the first packet sent by the client and is used for [[Authentication]].
+
See [[Block Actions]] for a list of values.
  
Contains the username of the connecting player, and the server host/port they're connecting to, most likely to allow [http://en.wikipedia.org/wiki/Virtual_hosting virtual hosting]. ([https://github.com/sadimusi/MVHP/blob/master/mvhp.py sample implementation])
+
{{Warning2|This packet uses a block ID from the <code>minecraft:block</code> registry, not a block state.}}
  
 
{| 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="4"| 0x08
| class="col1 centeralign" | Username and Host
+
| rowspan="4"| Play
| class="col2 centeralign" | string
+
| rowspan="4"| Client
| class="col3 centeralign" | <code>TkTech;localhost:25565</code>
+
| Location
| class="col4" | The username of the player attempting to connect, and the host he is connecting to, seperated by a semicolon.
+
| {{Type|Position}}
|- class="row2"
+
| Block coordinates.
! class="col0" | Total Size:
+
|-
| class="col1 rightalign" colspan="4" | 3 bytes + length of string
+
| Action ID (Byte 1)
|}
+
| {{Type|Unsigned Byte}}
 +
| Varies depending on block — see [[Block Actions]].
 +
|-
 +
| Action Parameter (Byte 2)
 +
| {{Type|Unsigned Byte}}
 +
| Varies depending on block — see [[Block Actions]].
 +
|-
 +
| Block Type
 +
| {{Type|VarInt}}
 +
| The block type ID for the block. This value is unused by the Notchian client, as it will infer the type of block based on the given position.
 +
|}
 +
 
 +
==== Block Update ====
  
==== Server to Client ====
+
Fired whenever a block is changed within the render distance.
  
This is the first packet sent by the server, in response to the client, and is used for [[Authentication]]
+
{{Warning2|Changing a block in a chunk that is not loaded is not a stable action.  The Notchian client currently uses a ''shared'' empty chunk which is modified for all block changes in unloaded chunks; while in 1.9 this chunk never renders in older versions the changed block will appear in all copies of the empty chunk.  Servers should avoid sending block changes in unloaded chunks and clients should ignore such packets.}}
  
 
{| class="wikitable"
 
{| class="wikitable"
|- 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="2"| 0x09
| class="col1 centeralign" | Connection Hash
+
| rowspan="2"| Play
| class="col2 centeralign" | string
+
| rowspan="2"| Client
| class="col3 rightalign" | <code>2e66f1dc032ab5f0</code>
+
| Location
| class="col4" | A unique, per-connection hash, '''or''' '+'
+
| {{Type|Position}}
|- class="row2"
+
| Block Coordinates.
! class="col0" | Total Size:
+
|-
| class="col1 rightalign" colspan="4" | 3 bytes + length of strings
+
| Block ID
|}
+
| {{Type|VarInt}}
 +
| The new block state ID for the block as given in the [[Chunk Format#Block state registry|block state registry]].
 +
|}
  
If connect hash is '+', the server is in offline mode and no name authentication needs to take place. The client will just send a 0x01 straight back, and the server won't perform the similar authentication step.
+
==== Boss Bar ====
  
Otherwise, it contains a randomly generated long as a series of hex digits. For details on what to do with it, see [[Authentication]]
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! colspan="2"| Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="14"| 0x0A
 +
| rowspan="14"| Play
 +
| rowspan="14"| Client
 +
| colspan="2"| UUID
 +
| {{Type|UUID}}
 +
| Unique ID for this bar.
 +
|-
 +
| colspan="2"| Action
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| Determines the layout of the remaining packet.
 +
|-
 +
! Action
 +
! Field Name
 +
!
 +
!
 +
|-
 +
| rowspan="5"| 0: add
 +
| Title
 +
| {{Type|Text Component}}
 +
|
 +
|-
 +
| Health
 +
| {{Type|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
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| Color ID (see below).
 +
|-
 +
| Division
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| Type of division (see below).
 +
|-
 +
| Flags
 +
| {{Type|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
 +
| {{Type|Float}}
 +
| ''as above''
 +
|-
 +
| 3: update title
 +
| Title
 +
| {{Type|Text Component}}
 +
|
 +
|-
 +
| rowspan="2"| 4: update style
 +
| Color
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| Color ID (see below).
 +
|-
 +
| Dividers
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| ''as above''
 +
|-
 +
| 5: update flags
 +
| Flags
 +
| {{Type|Unsigned Byte}}
 +
| ''as above''
 +
|}
  
=== Chat Message (0x03) ===
+
{| class="wikitable"
 +
! ID
 +
! Color
 +
|-
 +
| 0
 +
| Pink
 +
|-
 +
| 1
 +
| Blue
 +
|-
 +
| 2
 +
| Red
 +
|-
 +
| 3
 +
| Green
 +
|-
 +
| 4
 +
| Yellow
 +
|-
 +
| 5
 +
| Purple
 +
|-
 +
| 6
 +
| White
 +
|}
  
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.
+
{| class="wikitable"
 +
! ID
 +
! Type of division
 +
|-
 +
| 0
 +
| No division
 +
|-
 +
| 1
 +
| 6 notches
 +
|-
 +
| 2
 +
| 10 notches
 +
|-
 +
| 3
 +
| 12 notches
 +
|-
 +
| 4
 +
| 20 notches
 +
|}
  
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.
+
==== Change Difficulty ====
  
A message longer than 119 characters will cause the Beta (≥1.5) server and client <s>to crash</s> to print the message "Received string length longer than maximum allowed (X > 119)", with no side effects.
+
Changes the difficulty setting in the client's option menu
  
For more information, see [[Chat]].
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="2"| 0x0B
 +
| rowspan="2"| Play
 +
| rowspan="2"| Client
 +
| Difficulty
 +
| {{Type|Unsigned Byte}}
 +
| 0: peaceful, 1: easy, 2: normal, 3: hard.
 +
|-
 +
| Difficulty locked?
 +
| {{Type|Boolean}}
 +
|
 +
|}
 +
 
 +
==== Chunk Batch Finished ====
 +
 
 +
Marks the end of a chunk batch. The Notchian client marks the time it receives this packet and calculates the elapsed duration since the [[#Chunk Batch Start|beginning of the chunk batch]]. The server uses this duration and the batch size received in this packet to estimate the number of milliseconds elapsed per chunk received. This value is then used to calculate the desired number of chunks per tick through the formula <code>25 / millisPerChunk</code>, which is reported to the server through [[#Chunk Batch Received|Chunk Batch Received]]. This likely uses <code>25</code> instead of the normal tick duration of <code>50</code> so chunk processing will only use half of the client's and network's bandwidth.
 +
 
 +
The Notchian client uses the samples from the latest 15 batches to estimate the milliseconds per chunk number.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="1"| 0x0C
 +
| rowspan="1"| Play
 +
| rowspan="1"| Client
 +
| Batch size
 +
| {{Type|VarInt}}
 +
| Number of chunks.
 +
|}
 +
 
 +
==== Chunk Batch Start ====
 +
 
 +
Marks the start of a chunk batch. The Notchian client marks and stores the time it receives this 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" | 0x03
+
| 0x0D
| class="col1 centeralign" | Message
+
| Play
| class="col2 centeralign" | string
+
| Client
| class="col3 centeralign" | <code>&lt;Bob&gt; Hello World!</code>
+
| colspan="3"| ''no fields''
| class="col4" | User input '''must''' be sanitized server-side
+
|}
|- class="row2"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 3 bytes + length of strings
 
|}
 
  
=== Time Update (0x04) ===
+
==== Chunk Biomes ====
  
'''Server to Client only'''
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! colspan="2"| Field Name
 +
! colspan="2"| Field Type
 +
! Notes
 +
|-
 +
| rowspan="6"| 0x0E
 +
| rowspan="6"| Play
 +
| rowspan="6"| Client
 +
|-
 +
| colspan="2"| Number of chunks
 +
| colspan="2"| {{Type|VarInt}}
 +
| Number of elements in the following array
 +
|-
 +
| rowspan="4"| Chunk biome data
 +
| Chunk Z
 +
| rowspan="4"| {{Type|Array}}
 +
| {{Type|Int}}
 +
| Chunk coordinate (block coordinate divided by 16, rounded down)
 +
|-
 +
| Chunk X
 +
| {{Type|Int}}
 +
| Chunk coordinate (block coordinate divided by 16, rounded down)
 +
|-
 +
| Size
 +
| {{Type|VarInt}}
 +
| Size of Data in bytes
 +
|-
 +
| Data
 +
| {{Type|Byte Array}}
 +
| Chunk [[Chunk Format#Data structure|data structure]], with [[Chunk Format#Chunk_Section|sections]] containing only the <code>Biomes</code> field
 +
|}
  
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.
+
Note: The order of X and Z is inverted, because the client reads them as one big-endian {{Type|Long}}, with Z being the upper 32 bits.
 +
 
 +
==== Clear Titles ====
 +
 
 +
Clear the client's current title information, with the option to also reset it.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="1"| 0x0F
 +
| rowspan="1"| Play
 +
| rowspan="1"| Client
 +
| Reset
 +
| {{Type|Boolean}}
 +
|
 +
|}
 +
 
 +
==== Command Suggestions Response ====
 +
 
 +
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"| 0x10
 +
| rowspan="8"| Play
 +
| rowspan="8"| Client
 +
|-
 +
| colspan="2"| ID
 +
| colspan="2"| {{Type|VarInt}}
 +
| Transaction ID.
 +
|-
 +
| colspan="2"| Start
 +
| colspan="2"| {{Type|VarInt}}
 +
| Start of the text to replace.
 +
|-
 +
| colspan="2"| Length
 +
| colspan="2"| {{Type|VarInt}}
 +
| Length of the text to replace.
 +
|-
 +
| colspan="2"| Count
 +
| colspan="2"| {{Type|VarInt}}
 +
| Number of elements in the following array.
 +
|-
 +
| rowspan="3"| Matches
 +
| Match
 +
| rowspan="3"| {{Type|Array}}
 +
| {{Type|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
 +
| {{Type|Boolean}}
 +
| True if the following is present.
 +
|-
 +
| Tooltip
 +
| {{Type|Optional}} {{Type|Text Component}}
 +
| Tooltip to display; only present if previous boolean is true.
 +
|}
 +
 
 +
==== 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"| 0x11
 +
| rowspan="3"| Play
 +
| rowspan="3"| Client
 +
| Count
 +
| {{Type|VarInt}}
 +
| Number of elements in the following array.
 +
|-
 +
| Nodes
 +
| {{Type|Array}} of [[Command Data|Node]]
 +
| An array of nodes.
 +
|-
 +
| Root index
 +
| {{Type|VarInt}}
 +
| Index of the <code>root</code> node in the previous array.
 +
|}
 +
 
 +
For more information on this packet, see the [[Command Data]] article.
  
The time of day is based on the timestamp modulo 24000. 0 is sunrise, 6000 is noon, 12000 is sunset, and 18000 is midnight.
+
==== Close Container ====
  
The default SMP server increments the time by <code>20</code> every second.
+
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. The notchian client disregards the provided window ID and closes any active 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" | 0x04
+
| 0x12
| class="col1 centeralign" | Time
+
| Play
| class="col2 centeralign" | long
+
| Client
| class="col3 centeralign" | <code></code>
+
| Window ID
| class="col4 centeralign" | The world (or region) time, in ticks
+
| {{Type|Unsigned Byte}}
|- class="row2"
+
| This is the ID of the window that was closed. 0 for inventory.
! class="col0" | Total Size:
+
|}
| class="col1 rightalign" colspan="4" | 9 bytes
 
|}
 
  
=== Entity Equipment (0x05) ===
+
==== Set Container Content ====
 +
[[File:Inventory-slots.png|thumb|The inventory slots]]
  
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.
+
Replaces the contents of a container window. Sent by the server upon initialization of a container window or the player's inventory, and in response to state ID mismatches (see [[#Click Container]]).
  
 
{| 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="5"| 0x13
| class="col1 centeralign" | Entity ID
+
| rowspan="5"| Play
| class="col2 centeralign" | int
+
| rowspan="5"| Client
| class="col3 centeralign" | 0x00010643
+
| Window ID
| class="col4" | Named Entity ID
+
| {{Type|Unsigned Byte}}
|- class="row2"
+
| The ID of window which items are being sent for. 0 for player inventory. The client ignores any packets targeting a Window ID other than the current one. However, an exception is made for the player inventory, which may be targeted at any time. (The Notchian server does not appear to utilize this special case.)
| class="col0 centeralign" | Slot
+
|-
| class="col1 centeralign" | short
+
| State ID
| class="col2 centeralign" | 4
+
| {{Type|VarInt}}
| class="col3" | Equipment slot: 0=held, 1-4=armor slot
+
| A server-managed sequence number used to avoid desynchronization; see [[#Click Container]].
|- class="row3"
+
|-
| class="col0 centeralign" | Item ID
+
| Count
| class="col1 centeralign" | short
+
| {{Type|VarInt}}
| class="col2 centeralign" | -1
+
| Number of elements in the following array.
| class="col3" | Equipped item (-1 for empty slot)
+
|-
|- class="row4"
+
| Slot Data
| class="col0 centeralign" | Damage
+
| {{Type|Array}} of [[Slot Data|Slot]]
| class="col1 centeralign" | short
+
|-
| class="col2 centeralign" |  
+
| Carried Item
| class="col3" |
+
| {{Type|Slot}}
|- class="row5"
+
| Item being dragged with the mouse.
! class="col0" | Total Size:
+
|}
| class="col1 rightalign" colspan="4" | 11 bytes
 
|}
 
  
=== Spawn Position (0x06) ===
+
See [[Inventory#Windows|inventory windows]] for further information about how slots are indexed.
 +
Use [[#Open Screen|Open Screen]] to open the container on the client.
  
'''Server to Client only'''
+
==== Set Container Property ====
  
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.
+
This packet is used to inform the client that part of a GUI window should be updated.
  
 
{| 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="3"| 0x14
| class="col1 centeralign" | X
+
| rowspan="3"| Play
| class="col2 centeralign" | int
+
| rowspan="3"| Client
| class="col3 centeralign" | <code>117</code>
+
| Window ID
| class="col4 centeralign" | Spawn X in block coordinates
+
| {{Type|Unsigned Byte}}
|- class="row2"
+
|
| class="col0 centeralign" | Y
+
|-
| class="col1 centeralign" | int
+
| Property
| class="col2 centeralign" | <code>70</code>
+
| {{Type|Short}}
| class="col3 centeralign" | Spawn Y in block coordinates
+
| The property to be updated, see below.
|- class="row3"
+
|-
| class="col0 centeralign" | Z
+
| Value
| class="col1 centeralign" | int
+
| {{Type|Short}}
| class="col2 centeralign" | <code>-46</code>
+
| The new value for the property, see below.
| class="col3 centeralign" | Spawn Z in block coordinates
+
|}
|- class="row4"
+
 
! class="col0" | Total Size:
+
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="col1 rightalign" colspan="4" | 13 bytes
 
|}
 
  
=== Use Entity (0x07) ===
+
{| 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
 +
|-
 +
| Stonecutter
 +
| 0: Selected recipe
 +
| The index of the selected recipe. -1 means none is selected.
 +
|-
 +
| Loom
 +
| 0: Selected pattern
 +
| The index of the selected pattern. 0 means none is selected, 0 is also the internal id of the "base" pattern.
 +
|-
 +
| Lectern
 +
| 0: Page number
 +
| The current page number, starting from 0.
 +
|}
  
'''Client to Server only'''
+
For an enchanting table, the following numerical IDs are used:
  
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.
+
{| 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:soul_speed
 +
| Soul Speed
 +
|-
 +
| 12
 +
| minecraft:sharpness
 +
| Sharpness
 +
|-
 +
| 13
 +
| minecraft:smite
 +
| Smite
 +
|-
 +
| 14
 +
| minecraft:bane_of_arthropods
 +
| Bane of Arthropods
 +
|-
 +
| 15
 +
| minecraft:knockback
 +
| Knockback
 +
|-
 +
| 16
 +
| minecraft:fire_aspect
 +
| Fire Aspect
 +
|-
 +
| 17
 +
| minecraft:looting
 +
| Looting
 +
|-
 +
| 18
 +
| minecraft:sweeping
 +
| Sweeping Edge
 +
|-
 +
| 19
 +
| minecraft:efficiency
 +
| Efficiency
 +
|-
 +
| 20
 +
| minecraft:silk_touch
 +
| Silk Touch
 +
|-
 +
| 21
 +
| minecraft:unbreaking
 +
| Unbreaking
 +
|-
 +
| 22
 +
| minecraft:fortune
 +
| Fortune
 +
|-
 +
| 23
 +
| minecraft:power
 +
| Power
 +
|-
 +
| 24
 +
| minecraft:punch
 +
| Punch
 +
|-
 +
| 25
 +
| minecraft:flame
 +
| Flame
 +
|-
 +
| 26
 +
| minecraft:infinity
 +
| Infinity
 +
|-
 +
| 27
 +
| minecraft:luck_of_the_sea
 +
| Luck of the Sea
 +
|-
 +
| 28
 +
| minecraft:lure
 +
| Lure
 +
|-
 +
| 29
 +
| minecraft:loyalty
 +
| Loyalty
 +
|-
 +
| 30
 +
| minecraft:impaling
 +
| Impaling
 +
|-
 +
| 31
 +
| minecraft:riptide
 +
| Riptide
 +
|-
 +
| 32
 +
| minecraft:channeling
 +
| Channeling
 +
|-
 +
| 33
 +
| minecraft:multishot
 +
| Multishot
 +
|-
 +
| 34
 +
| minecraft:quick_charge
 +
| Quick Charge
 +
|-
 +
| 35
 +
| minecraft:piercing
 +
| Piercing
 +
|-
 +
| 36
 +
| minecraft:mending
 +
| Mending
 +
|-
 +
| 37
 +
| minecraft:vanishing_curse
 +
| Curse of Vanishing
 +
|}
  
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.
+
==== Set Container Slot ====
  
(This packet data values are not fully verified)
+
Sent by the server when an item in a slot (in a window) is added/removed.
  
 
{| 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="4"| 0x15
| class="col1 centeralign" | User
+
| rowspan="4"| Play
| class="col2 centeralign" | int
+
| rowspan="4"| Client
| class="col3 centeralign" | <code>1298</code>
+
| Window ID
| class="col4" | The entity of the player (ignored by the server)
+
| {{Type|Byte}}
|- class="row2"
+
| The window which is being updated. 0 for player inventory. The client ignores any packets targeting a Window ID other than the current one; see below for exceptions.
| class="col0 centeralign" | Target
+
|-
| class="col1 centeralign" | int
+
| State ID
| class="col2 centeralign" | <code>1805</code>
+
| {{Type|VarInt}}
| class="col3" | The entity the player is interacting with
+
| A server-managed sequence number used to avoid desynchronization; see [[#Click Container]].
|- class="row3"
+
|-
| class="col0 centeralign" | Left-click?
+
| Slot
| class="col1 centeralign" | bool
+
| {{Type|Short}}
| class="col2 centeralign" | <code>true</code>
+
| The slot that should be updated.
| 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"
+
| Slot Data
! class="col0" | Total Size:
+
| {{Type|Slot}}
| class="col1 rightalign" colspan="4" | 10 bytes
+
|
|}
+
|}
 +
 
 +
If Window ID is 0, the hotbar and offhand slots (slots 36 through 45) may be updated even when a different container window is open. (The Notchian server does not appear to utilize this special case.) Updates are also restricted to those slots when the player is looking at a creative inventory tab other than the survival inventory. (The Notchian server does ''not'' handle this restriction in any way, leading to [https://bugs.mojang.com/browse/MC-242392 MC-242392].)
 +
 
 +
If Window ID is -1, the item being dragged with the mouse is set. In this case, State ID and Slot are ignored.
  
=== Update Health (0x08) ===
+
If Window ID is -2, any slot in the player's inventory can be updated irrespective of the current container window. In this case, State ID is ignored, and the Notchian server uses a bogus value of 0. Used by the Notchian server to implement the [[#Pick Item]] functionality.
  
'''Server to Client only'''
+
When a container window is open, the server never sends updates targeting Window ID 0&mdash;all of the [[Inventory|window types]] include slots for the player inventory. The client must automatically apply changes targeting the inventory portion of a container window to the main inventory; the server does not resend them for ID 0 when the window is closed. However, since the armor and offhand slots are only present on ID 0, updates to those slots occurring while a window is open must be deferred by the server until the window's closure.
  
Sent by the server to update/set the health of the player it is sent to. Added in protocol version 5.
+
==== Set Cooldown ====
  
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.
+
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"
 
{| 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" | 0x08
+
| rowspan="2"| 0x16
| class="col1 centeralign" | Health
+
| rowspan="2"| Play
| class="col2 centeralign" | short
+
| rowspan="2"| Client
| class="col3 centeralign" | 20
+
| Item ID
| class="col4" | 0 or less = dead, 20 = full HP
+
| {{Type|VarInt}}
|- class="row2"
+
| Numeric ID of the item to apply a cooldown to.
| class="col1 centeralign" | Food
+
|-
| class="col2 centeralign" | short
+
| Cooldown Ticks
| class="col3 centeralign" | 20
+
| {{Type|VarInt}}
| class="col4" | 0 - 20
+
| Number of ticks to apply a cooldown for, or 0 to clear the cooldown.
|- class="row3"
+
|}
| class="col1 centeralign" | Food Saturation
 
| class="col2 centeralign" | float
 
| class="col3 centeralign" | 5.0
 
| class="col4" | Seems to vary from 0.0 to 5.0 in integer increments
 
|- class="row4"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 9 bytes
 
|}
 
  
=== Respawn (0x09) ===
+
==== Chat Suggestions ====
  
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.
+
Unused by the Notchian server. Likely provided for custom servers to send chat message completions to clients.
  
 
{| 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" | 0x09
+
| rowspan="3"| 0x17
| class="col1 centeralign" | Dimension
+
| rowspan="3"| Play
| class="col2 centeralign" | int
+
| rowspan="3"| Client
| class="col3 centeralign" | <code>1</code>
+
| Action
| class="col4" | <code>-1</code>: The Nether, <code>0</code>: The Overworld, <code>1</code>: The End
+
| {{Type|VarInt}} {{Type|Enum}}
|- class="row2"
+
| 0: Add, 1: Remove, 2: Set
| class="col1 centeralign" | Difficulty
+
|-
| class="col2 centeralign" | byte
+
| Count
| class="col3 centeralign" | <code>1</code>
+
| {{Type|VarInt}}
| class="col4" | <code>0</code> thru <code>3</code> for Peaceful, Easy, Normal, Hard. <code>1</code> is always sent c->s
+
| Number of elements in the following array.
|- class="row3"
+
|-
| class="col1 centeralign" | Creative mode
+
| Entries
| class="col2 centeralign" | byte
+
| {{Type|Array}} of {{Type|String}} (32767)
| class="col3 centeralign" | <code>1</code>
+
|
| class="col4" | <code>0</code> for survival, <code>1</code> for creative.
+
|}
|- class="row4"
 
| class="col1 centeralign" | World height
 
| class="col2 centeralign" | short
 
| class="col3 centeralign" | <code>128</code>
 
| class="col4" | Defaults to <code>128</code>
 
|- class="row5"
 
| class="col1 centeralign" | Level Type
 
| class="col2 centeralign" | string
 
| class="col3 centeralign" | DEFAULT
 
| class="col4" | See 0x01 login
 
|- class="row6"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 11 bytes + length of string
 
|}
 
  
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.
+
==== Clientbound Plugin Message (play) ====
  
=== Player (0x0A) ===
+
{{Main|Plugin channels}}
  
'''Client to Server only'''
+
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.
  
This packet is used to indicate whether the player is on ground (walking/swimming), or airborne (jumping/falling).
+
More information on how it works on [https://dinnerbone.com/blog/2012/01/13/minecraft-plugin-channels-messaging/ Dinnerbone's blog]. More documentation about internal and popular registered channels are [[plugin channel|here]].
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="2"| 0x18
 +
| rowspan="2"| Play
 +
| rowspan="2"| Client
 +
| Channel
 +
| {{Type|Identifier}}
 +
| Name of the [[plugin channel]] used to send the data.
 +
|-
 +
| Data
 +
| {{Type|Byte Array}} (1048576)
 +
| Any data. The length of this array must be inferred from the packet length.
 +
|}
 +
 
 +
In Notchian client, the maximum data length is 1048576 bytes.
 +
 
 +
==== Damage Event ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! colspan="2"| Field Name
 +
! colspan="2"| Field Type
 +
! Notes
 +
|-
 +
| rowspan="9"| 0x19
 +
| rowspan="9"| Play
 +
| rowspan="9"| Client
 +
|-
 +
| colspan="2"| Entity ID
 +
| colspan="2"| {{Type|VarInt}}
 +
| The ID of the entity taking damage
 +
|-
 +
| colspan="2"| Source Type ID
 +
| colspan="2"| {{Type|VarInt}}
 +
| The type of damage in the <code>minecraft:damage_type</code> registry, defined by the [[Protocol#Registry_Data|Registry Data]] packet.
 +
|-
 +
| colspan="2"| Source Cause ID
 +
| colspan="2"| {{Type|VarInt}}
 +
| The ID + 1 of the entity responsible for the damage, if present. If not present, the value is 0
 +
|-
 +
| colspan="2"| Source Direct ID
 +
| colspan="2"| {{Type|VarInt}}
 +
| The ID + 1 of the entity that directly dealt the damage, if present. If not present, the value is 0. If this field is present:
 +
* and damage was dealt indirectly, such as by the use of a projectile, this field will contain the ID of such projectile;
 +
* and damage was dealt dirctly, such as by manually attacking, this field will contain the same value as Source Cause ID.
 +
|-
 +
| colspan="2"| Has Source Position
 +
| colspan="2"| {{Type|Boolean}}
 +
| Indicates the presence of the three following fields.
 +
The Notchian server sends the Source Position when the damage was dealt by the /damage command and a position was specified
 +
|-
 +
| colspan="2"| Source Position X
 +
| colspan="2"| {{Type|Optional}} {{Type|Double}}
 +
| Only present if Has Source Position is true
 +
|-
 +
| colspan="2"| Source Position Y
 +
| colspan="2"| {{Type|Optional}} {{Type|Double}}
 +
| Only present if Has Source Position is true
 +
|-
 +
| colspan="2"| Source Position Z
 +
| colspan="2"| {{Type|Optional}} {{Type|Double}}
 +
| Only present if Has Source Position is true
 +
|}
 +
 
 +
==== Delete Message ====
 +
 
 +
Removes a message from the client's chat. This only works for messages with signatures, system messages cannot be deleted with this packet.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="2"| 0x1A
 +
| rowspan="2"| Play
 +
| rowspan="2"| Client
 +
| Message ID
 +
| {{Type|VarInt}}
 +
| The message Id + 1, used for validating message signature. The next field is present only when value of this field is equal to 0.
 +
|-
 +
| Signature
 +
| {{Type|Optional}} {{Type|Byte Array}} (256)
 +
| The previous message's signature. Always 256 bytes and not length-prefixed.
 +
|}
  
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.
+
==== Disconnect (play) ====
  
This packet was previously referred to as Flying
+
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"
 
{| 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" | 0x0A
+
| 0x1B
| class="col1 centeralign" | On Ground
+
| Play
| class="col2 centeralign" | bool
+
| Client
| class="col3 centeralign" | <code>1</code>
+
| Reason
| class="col4" | <code>True</code> if the client is on the ground, <code>False</code> otherwise
+
| {{Type|Text Component}}
|- class="row2"
+
| Displayed to the client when the connection terminates.
! class="col0" | Total Size:
+
|}
| class="col1 rightalign" colspan="4" | 2 bytes
 
|}
 
  
=== Player Position (0x0B) ===
+
==== Disguised Chat Message ====
  
'''Client to Server''' (player-controlled movement).
+
Sends the client a chat message, but without any message signing information.
  
Updates the players XYZ position on the server.
+
The Notchian server uses this packet when the console is communicating with players through commands, such as <code>/say</code>, <code>/tell</code>, <code>/me</code>, among others.
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”.
 
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 units will result in the client being kicked for "You moved too quickly :( (Hacking?)"
 
Also if the absolute number of X or Z is set greater than <code>3.2E7D</code> the client will be kicked for "Illegal position"
 
  
 +
{| class="wikitable
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="5"| 0x1C
 +
| rowspan="5"| Play
 +
| rowspan="5"| Client
 +
| Message
 +
| {{Type|Text Component}}
 +
| This is used as the <code>content</code> parameter when formatting the message on the client.
 +
|-
 +
| Chat Type
 +
| {{Type|VarInt}}
 +
| The type of chat in the <code>minecraft:chat_type</code> registry, defined by the [[Protocol#Registry_Data|Registry Data]] packet.
 +
|-
 +
| Sender Name
 +
| {{Type|Text Component}}
 +
| The name of the one sending the message, usually the sender's display name.
 +
This is used as the <code>sender</code> parameter when formatting the message on the client.
 +
|-
 +
| Has Target Name
 +
| {{Type|Boolean}}
 +
| True if target name is present.
 +
|-
 +
| Target Name
 +
| {{Type|Text Component}}
 +
| The name of the one receiving the message, usually the receiver's display name. Only present if previous boolean is true.
 +
This is used as the <code>target</code> parameter when formatting the message on the client.
 +
|}
 +
 +
==== Entity Event ====
 +
 +
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"
 
{| 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="2"| 0x1D
| class="col1 centeralign" | X
+
| rowspan="2"| Play
| class="col2 centeralign" | double
+
| rowspan="2"| Client
| class="col3 rightalign" | <code>102.809</code>
+
| Entity ID
| class="col4" | Absolute position
+
| {{Type|Int}}
|- class="row2"
+
|
| class="col0 centeralign" | Y
+
|-
| class="col1 centeralign" | double
+
| Entity Status
| class="col2 centeralign" | <code>70.00</code>
+
| {{Type|Byte}} {{Type|Enum}}
| class="col3" | Absolute position
+
| See [[Entity statuses]] for a list of which statuses are valid for each type of entity.
|- class="row3"
+
|}
| class="col0 centeralign" | Stance
 
| class="col1 centeralign" | double
 
| class="col2 centeralign" | <code>71.62</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>68.30</code>
 
| class="col3" | Absolute position
 
|- class="row5"
 
| class="col0 centeralign" | On Ground
 
| class="col1 centeralign" | bool
 
| class="col2 centeralign" | <code>1</code>
 
| class="col3" |
 
Derived from packet [[#Player_.280x0A.29|0x0A]]
 
|- class="row6"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 34 bytes
 
|}
 
  
=== Player Look (0x0C) ===
+
==== Explosion ====
  
'''Client to Server''' (player-controlled movement).
+
Sent when an explosion occurs (creepers, TNT, and ghast fireballs).
  
[[File:Minecraft-trig-yaw.png|thumb|The unit circle for yaw]]
+
Each block in Records is set to air. Coordinates for each axis in record is int(X) + record.x
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! colspan="2" | Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="17"| 0x1E
 +
| rowspan="17"| Play
 +
| rowspan="17"| Client
 +
| colspan="2" | X
 +
| {{Type|Double}}
 +
|
 +
|-
 +
| colspan="2" | Y
 +
| {{Type|Double}}
 +
|
 +
|-
 +
| colspan="2" | Z
 +
| {{Type|Double}}
 +
|
 +
|-
 +
| colspan="2" | Strength
 +
| {{Type|Float}}
 +
| If the strength is greater or equal to 2.0, or the block interaction is not 0 (keep), large explosion particles are used. Otherwise, small explosion particles are used.
 +
|-
 +
| colspan="2" | Record Count
 +
| {{Type|VarInt}}
 +
| Number of elements in the following array.
 +
|-
 +
| colspan="2" | Records
 +
| {{Type|Array}} of ({{Type|Byte}}, {{Type|Byte}}, {{Type|Byte}})
 +
| Each record is 3 signed bytes long; the 3 bytes are the XYZ (respectively) signed offsets of affected blocks.
 +
|-
 +
| colspan="2" | Player Motion X
 +
| {{Type|Float}}
 +
| X velocity of the player being pushed by the explosion.
 +
|-
 +
| colspan="2" | Player Motion Y
 +
| {{Type|Float}}
 +
| Y velocity of the player being pushed by the explosion.
 +
|-
 +
| colspan="2" | Player Motion Z
 +
| {{Type|Float}}
 +
| Z velocity of the player being pushed by the explosion.
 +
|-
 +
| colspan="2" | Block Interaction
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| 0 = keep, 1 = destroy, 2 = destroy_with_decay, 3 = trigger_block.
 +
|-
 +
| colspan="2" | Small Explosion Particle ID
 +
| {{Type|VarInt}}
 +
| The particle ID listed in [[Particles]].
 +
|-
 +
| colspan="2" | Small Explosion Particle Data
 +
| Varies
 +
| Particle data as specified in [[Particles]].
 +
|-
 +
| colspan="2" | Large Explosion Particle ID
 +
| {{Type|VarInt}}
 +
| The particle ID listed in [[Particles]].
 +
|-
 +
| colspan="2" | Large Explosion Particle Data
 +
| Varies
 +
| Particle data as specified in [[Particles]].
 +
|-
 +
| rowspan="3" | Explosion Sound
 +
| Sound Name
 +
| {{Type|Identifier}}
 +
| The name of the sound played.
 +
|-
 +
| Has Fixed Range
 +
| {{Type|Optional}} {{Type|Boolean}}
 +
| Whether is has fixed range.
 +
|-
 +
| Range
 +
| {{Type|Optional}} {{Type|Float}}
 +
| The fixed range of the sound. Only present if previous boolean is true.
 +
|}
 +
 
 +
==== Unload Chunk ====
 +
 
 +
Tells the client to unload a chunk column.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="2"| 0x1F
 +
| rowspan="2"| Play
 +
| rowspan="2"| Client
 +
| Chunk Z
 +
| {{Type|Int}}
 +
| Block coordinate divided by 16, rounded down.
 +
|-
 +
| Chunk X
 +
| {{Type|Int}}
 +
| Block coordinate divided by 16, rounded down.
 +
|}
 +
 
 +
Note: The order is inverted, because the client reads this packet as one big-endian {{Type|Long}}, with Z being the upper 32 bits.
 +
 
 +
It is legal to send this packet even if the given chunk is not currently loaded.
  
Updates the direction the player is looking in.
+
==== Game Event ====
  
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.
+
Used for a wide variety of game events, from weather to bed use to game mode to demo messages.
  
Pitch is measured in degrees, where 0 is looking straight ahead, -90 is looking straight up, and 90 is looking straight down.
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="2"| 0x20
 +
| rowspan="2"| Play
 +
| rowspan="2"| Client
 +
| Event
 +
| {{Type|Unsigned Byte}}
 +
| See below.
 +
|-
 +
| Value
 +
| {{Type|Float}}
 +
| Depends on Event.
 +
|}
  
You can get a unit vector from a given yaw/pitch via:
+
''Events'':
  x = -cos(pitch) * sin(yaw)
 
  y = -sin(pitch)
 
  z =  cos(pitch) * cos(yaw)
 
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Event
! class="col0" | Packet ID
+
! Effect
! class="col1" | Field Name
+
! Value
! class="col2" | Field Type
+
|-
! class="col3" | Example
+
| 0
! class="col4" | Notes
+
| No respawn block available
|- class="row1"
+
| Note: Displays message 'block.minecraft.spawn.not_valid' (You have no home bed or charged respawn anchor, or it was obstructed) to the player.
| class="col0 centeralign" rowspan="3" | 0x0C
+
|-
| class="col1 centeralign" | Yaw
+
| 1
| class="col2 centeralign" | float
+
| End raining
| class="col3 centeralign" | <code>0.00</code>
+
|
| class="col4" | Absolute rotation on the X Axis, in degrees
+
|-
|- class="row2"
+
| 2
| class="col0 centeralign" | Pitch
+
| Begin raining
| class="col1 centeralign" | float
+
|
| class="col2 centeralign" | <code>0.00</code>
+
|-
| class="col3" | Absolute rotation on the Y Axis, in degrees
+
| 3
|- class="row3"
+
| Change game mode
| class="col0 centeralign" | On Ground
+
| 0: Survival, 1: Creative, 2: Adventure, 3: Spectator.
| class="col1 centeralign" | bool
+
|-
| class="col2 centeralign" | <code>1</code>
+
| 4
| class="col3" |
+
| Win game
Derived from packet [[#Player_.280x0A.29|0x0A]]
+
| 0: Just respawn player.<br>1: Roll the credits and respawn player.<br>Note that 1 is only sent by notchian server when player has not yet achieved advancement "The end?", else 0 is sent.
|- class="row4"
+
|-
! class="col0" | Total Size:
+
| 5
| class="col1 rightalign" colspan="4" | 10 bytes
+
| Demo event
|}
+
| 0: Show welcome to demo screen.<br>101: Tell movement controls.<br>102: Tell jump control.<br>103: Tell inventory control.<br>104: Tell that the demo is over and print a message about how to take a screenshot.
 +
|-
 +
| 6
 +
| Arrow hit player
 +
| Note: Sent when any player is struck by an arrow.
 +
|-
 +
| 7
 +
| Rain level change
 +
| Note: Seems to change both sky color and lighting.<br>Rain level ranging from 0 to 1.
 +
|-
 +
| 8
 +
| Thunder level change
 +
| Note: Seems to change both sky color and lighting (same as Rain level change, but doesn't start rain). It also requires rain to render by notchian client.<br>Thunder level ranging from 0 to 1.
 +
|-
 +
| 9
 +
| Play pufferfish sting sound
 +
|-
 +
| 10
 +
| Play elder guardian mob appearance (effect and sound)
 +
|
 +
|-
 +
| 11
 +
| Enable respawn screen
 +
| 0: Enable respawn screen.<br>1: Immediately respawn (sent when the <code>doImmediateRespawn</code> gamerule changes).
 +
|-
 +
| 12
 +
| Limited crafting
 +
| 0: Disable limited crafting.<br>1: Enable limited crafting (sent when the <code>doLimitedCrafting</code> gamerule changes).
 +
|-
 +
| 13
 +
| Start waiting for level chunks
 +
| Instructs the client to begin the waiting process for the level chunks.<br>Sent by the server after the level is cleared on the client and is being re-sent (either during the first, or subsequent reconfigurations).
 +
|}
 +
 
 +
==== Open Horse Screen ====
 +
 
 +
This packet is used exclusively for opening the horse GUI. [[#Open Screen|Open Screen]] is used for all other GUIs.  The client will not open the inventory if the Entity ID does not point to an horse-like animal.
  
=== Player Position &amp; Look (0x0D) ===
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="3"| 0x21
 +
| rowspan="3"| Play
 +
| rowspan="3"| Client
 +
| Window ID
 +
| {{Type|Unsigned Byte}}
 +
|
 +
|-
 +
| Slot count
 +
| {{Type|VarInt}}
 +
|
 +
|-
 +
| Entity ID
 +
| {{Type|Int}}
 +
|
 +
|}
  
A combination of [[#Player_Look_.280x0C.29|Player Look]] and [[#Player_Position_.280x0B.29|Player position]].
+
==== Hurt Animation ====
  
==== Client to Server ====
+
Plays a bobbing animation for the entity receiving damage.
  
 
{| 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="7" | 0x0D
+
| rowspan="3"| 0x22
| class="col1 centeralign" | X
+
| rowspan="3"| Play
| class="col2 centeralign" | double
+
| rowspan="3"| Client
| class="col3 centeralign" | <code>6.5</code>
+
|-
| class="col4" | Absolute position
+
| colspan="2"| Entity ID
|- class="row2"
+
| colspan="2"| {{Type|VarInt}}
| class="col0 centeralign" | Y
+
| The ID of the entity taking damage
| class="col1 centeralign" | double
+
|-
| class="col2 centeralign" | <code>65.620000004768372</code>
+
| colspan="2"| Yaw
| class="col3" | Absolute position
+
| colspan="2"| {{Type|Float}}
|- class="row3"
+
| The direction the damage is coming from in relation to the entity
| 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
 
|}
 
  
==== Server to Client ====
+
==== Initialize 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
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="7" | 0x0D
+
| rowspan="8"| 0x23
| class="col1 centeralign" | X
+
| rowspan="8"| Play
| class="col2 centeralign" | double
+
| rowspan="8"| Client
| class="col3 centeralign" | <code>6.5</code>
+
| X
| class="col4" | Absolute position
+
| {{Type|Double}}
|- class="row2"
+
|
| class="col0 centeralign" | Stance
+
|-
| class="col1 centeralign" | double
+
| Z
| class="col2 centeralign" | <code>67.240000009536743</code>
+
| {{Type|Double}}
| class="col3" | Used to modify the players bounding box when going up stairs, crouching, etc…
+
|
|- class="row3"
+
|-
| class="col0 centeralign" | Y
+
| Old Diameter
| class="col1 centeralign" | double
+
| {{Type|Double}}
| class="col2 centeralign" | <code>65.620000004768372</code>
+
| Current length of a single side of the world border, in meters.
| class="col3" | Absolute position
+
|-
|- class="row4"
+
| New Diameter
| class="col0 centeralign" | Z
+
| {{Type|Double}}
| class="col1 centeralign" | double
+
| Target length of a single side of the world border, in meters.
| class="col2 centeralign" | <code>7.5</code>
+
|-
| class="col3" | Absolute position
+
| Speed
|- class="row5"
+
| {{Type|VarLong}}
| class="col0 centeralign" | Yaw
+
| 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="col1 centeralign" | float
+
|-
| class="col2 centeralign" | <code>0.0</code>
+
| Portal Teleport Boundary
| class="col3" | Absolute rotation on the X Axis
+
| {{Type|VarInt}}
|- class="row6"
+
| Resulting coordinates from a portal teleport are limited to ±value. Usually 29999984.
| class="col0 centeralign" | Pitch
+
|-
| class="col1 centeralign" | float
+
| Warning Blocks
| class="col2 centeralign" | <code>0.0</code>
+
| {{Type|VarInt}}
| class="col3" | Absolute rotation on the Y Axis
+
| In meters.
|- class="row7"
+
|-
| class="col0 centeralign" | On Ground
+
| Warning Time
| class="col1 centeralign" | bool
+
| {{Type|VarInt}}
| class="col2 centeralign" | <code>0</code>
+
| In seconds as set by <code>/worldborder warning time</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.
+
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:
  
[[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 ! [BackBone`:] The opposite stance<->y confirmed, however the given structs had the server and client struct reversed, which I fixed.
+
<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>
  
[[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.
+
==== Clientbound Keep Alive (play) ====
  
=== Player Digging (0x0E) ===
+
The server will frequently send out a keep-alive, each containing a random ID. The client must respond with the same payload (see [[#Serverbound Keep Alive (play)|Serverbound Keep Alive]]). 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.
  
Sent when the player mines a block.  A Notchian server only accepts digging packets with coordinates within a 6-unit radius of the player's position.
+
The Notchian server uses a system-dependent time in milliseconds to generate the keep alive ID value.
  
 
{| 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
+
| 0x24
| class="col1 centeralign" | Status
+
| Play
| class="col2 centeralign" | byte
+
| Client
| class="col3 centeralign" | <code>1</code>
+
| Keep Alive ID
| class="col4" | The action the player is taking against the block (see below)
+
| {{Type|Long}}
|- class="row2"
+
|
| class="col0 centeralign" | X
+
|}
| class="col1 centeralign" | int
 
| class="col2 centeralign" | <code>32</code>
 
| class="col3" | Block position
 
|- class="row3"
 
| class="col0 centeralign" | Y
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>64</code>
 
| class="col3" | Block position
 
|- class="row4"
 
| class="col0 centeralign" | Z
 
| class="col1 centeralign" | int
 
| class="col2 centeralign" | <code>32</code>
 
| class="col3 leftalign" | Block position
 
|- class="row5"
 
| class="col0 centeralign" | Face
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>3</code>
 
| class="col3" | The face being hit (see below)
 
|- class="row6"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 12 bytes
 
|}
 
  
Status can (currently) be one of four values:
+
==== Chunk Data and Update Light ====
 +
{{Main|Chunk Format}}
 +
{{See also|#Unload Chunk}}
  
 +
Sent when a chunk comes into the client's view distance, specifying its terrain, lighting and block entities.
 +
 +
The chunk must be within the view area previously specified with [[#Set Center Chunk|Set Center Chunk]]; see that packet for details.
 +
 +
It is not strictly necessary to send all block entities in this packet; it is still legal to send them with [[#Block Entity Data|Block Entity Data]] later.
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Meaning
+
! State
! class="col1" | Value
+
! Bound To
|- class="row1"
+
! colspan="2"| Field Name
| class="col0 leftalign" | Started digging
+
! colspan="2"| Field Type
| class="col1 centeralign" | <code>0</code>
+
! Notes
|- class="row2"
+
|-
| class="col0 leftalign" | Finished digging
+
| rowspan="20"| 0x25
| class="col1 centeralign" | <code>2</code>
+
| rowspan="20"| Play
|- class="row3"
+
| rowspan="20"| Client
| class="col0 leftalign" | Drop item
+
| colspan="2"| Chunk X
| class="col1 centeralign" | <code>4</code>
+
| colspan="2"| {{Type|Int}}
|- class="row4"
+
| Chunk coordinate (block coordinate divided by 16, rounded down)
| class="col0 leftalign" | Shoot arrow / finish eating
+
|-
| class="col1 centeralign" | <code>5</code>
+
| colspan="2"| Chunk Z
|}
+
| colspan="2"| {{Type|Int}}
 +
| Chunk coordinate (block coordinate divided by 16, rounded down)
 +
|-
 +
| colspan="2"| Heightmaps
 +
| colspan="2"| [[NBT]]
 +
| See [[Chunk Format#Heightmaps structure]]
 +
|-
 +
| colspan="2"| Size
 +
| colspan="2"| {{Type|VarInt}}
 +
| Size of Data in bytes
 +
|-
 +
| colspan="2"| Data
 +
| colspan="2"| {{Type|Byte Array}}
 +
| See [[Chunk Format#Data structure]]
 +
|-
 +
| colspan="2"| Number of block entities
 +
| colspan="2"| {{Type|VarInt}}
 +
| Number of elements in the following array
 +
|-
 +
| rowspan="4"| Block Entity
 +
| Packed XZ
 +
| rowspan="4"| {{Type|Array}}
 +
| {{Type|Unsigned Byte}}
 +
| The packed section coordinates are relative to the chunk they are in. Values 0-15 are valid. <pre>packed_xz = ((blockX & 15) << 4) | (blockZ & 15) // encode
 +
x = packed_xz >> 4, z = packed_xz & 15 // decode</pre>
 +
|-
 +
| Y
 +
| {{Type|Short}}
 +
| The height relative to the world
 +
|-
 +
| Type
 +
| {{Type|VarInt}}
 +
| The type of block entity
 +
|-
 +
| Data
 +
| [[NBT]]
 +
| The block entity's data, without the X, Y, and Z values
 +
|-
 +
| colspan="2"| Sky Light Mask
 +
| colspan="2"| {{Type|BitSet}}
 +
| BitSet containing bits for each section in the world + 2.  Each set bit indicates that the corresponding 16×16×16 chunk section has data in the Sky Light array below.  The least significant bit is for blocks 16 blocks to 1 block below the min world height (one section below the world), while the most significant bit covers blocks 1 to 16 blocks above the max world height (one section above the world).
 +
|-
 +
| colspan="2"| Block Light Mask
 +
| colspan="2"| {{Type|BitSet}}
 +
| BitSet containing bits for each section in the world + 2.  Each set bit indicates that the corresponding 16×16×16 chunk section has data in the Block Light array below.  The order of bits is the same as in Sky Light Mask.
 +
|-
 +
| colspan="2"| Empty Sky Light Mask
 +
| colspan="2"| {{Type|BitSet}}
 +
| BitSet containing bits for each section in the world + 2.  Each set bit indicates that the corresponding 16×16×16 chunk section has all zeros for its Sky Light data.  The order of bits is the same as in Sky Light Mask.
 +
|-
 +
| colspan="2"| Empty Block Light Mask
 +
| colspan="2"| {{Type|BitSet}}
 +
| BitSet containing bits for each section in the world + 2.  Each set bit indicates that the corresponding 16×16×16 chunk section has all zeros for its Block Light data.  The order of bits is the same as in Sky Light Mask.
 +
|-
 +
| colspan="2"| Sky Light array count
 +
| colspan="2"| {{Type|VarInt}}
 +
| Number of entries in the following array; should match the number of bits set in Sky Light Mask
 +
|-
 +
| rowspan="2"| Sky Light arrays
 +
| Length
 +
| rowspan="2"| {{Type|Array}}
 +
| {{Type|VarInt}}
 +
| Length of the following array in bytes (always 2048)
 +
|-
 +
| Sky Light array
 +
| {{Type|Byte Array}} (2048)
 +
| 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. Indexed <code><nowiki>((y<<8) | (z<<4) | x) / 2 </nowiki></code> If there's a remainder, masked 0xF0 else 0x0F.
 +
|-
 +
| colspan="2"| Block Light array count
 +
| colspan="2"| {{Type|VarInt}}
 +
| Number of entries in the following array; should match the number of bits set in Block Light Mask
 +
|-
 +
| rowspan="2"| Block Light arrays
 +
| Length
 +
| rowspan="2"| {{Type|Array}}
 +
| {{Type|VarInt}}
 +
| Length of the following array in bytes (always 2048)
 +
|-
 +
| Block Light array
 +
| {{Type|Byte Array}} (2048)
 +
| 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. Indexed <code><nowiki>((y<<8) | (z<<4) | x) / 2 </nowiki></code> If there's a remainder, masked 0xF0 else 0x0F.
 +
|}
  
Notchian clients send a 0 (started digging) when they start digging and a 2 (finished digging) once they think they are finished. If digging is aborted, no notice is sent to the server; the client simply does not send a 2 (finished digging).
+
Unlike the [[#Update Light|Update Light]] packet which uses the same format, setting the bit corresponding to a section to 0 in both of the block light or sky light masks does not appear to be useful, and the results in testing have been highly inconsistent.
  
Status code 4 (drop item) is a special case.  In-game, when you use the Drop Item command (keypress 'q'), a dig packet with a status of 4, and all other values set to 0, is sent from client to server.
+
==== World Event ====
 +
Sent when a client is to play a sound or particle effect.
  
The face can be one of six values, representing the face being hit:
+
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.
  
 
{| 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="4"| 0x26
|- class="row1"
+
| rowspan="4"| Play
! class="col0 leftalign" | Offset
+
| rowspan="4"| Client
| class="col1" | -Y
+
| Event
| class="col2" | +Y
+
| {{Type|Int}}
| class="col3" | -Z
+
| The event, see below.
| class="col4" | +Z
+
|-
| class="col5" | -X
+
| Location
| class="col6" | +X
+
| {{Type|Position}}
|}
+
| The location of the event.
 +
|-
 +
| Data
 +
| {{Type|Int}}
 +
| Extra data for certain events, see below.
 +
|-
 +
| Disable Relative Volume
 +
| {{Type|Boolean}}
 +
| See above.
 +
|}
  
In 1.7.3, when a player opens a door with left click the server receives Packet 0xE+start digging and opens the door.
+
Events:
  
=== Player Block Placement (0x0F) ===
+
{| 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
 +
|
 +
|-
 +
| 1009
 +
| Fire extinguished
 +
|
 +
|-
 +
| 1010
 +
| Play record
 +
| An ID in the <code>minecraft:item</code> registry, corresponding to a {{Minecraft Wiki|Music Disc|record item}}. If the ID doesn't correspond to a record, the packet is ignored. Any record already being played at the given location is overwritten. See [[Data Generators]] for information on item IDs.
 +
|-
 +
| 1011
 +
| Stop record
 +
|
 +
|-
 +
| 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 ID (see [[Chunk Format#Block state registry]]).
 +
|-
 +
| 2002
 +
| Splash potion. Particle effect + glass break sound.
 +
| RGB color as an integer (e.g. 8364543 for #7FA1FF).
 +
|-
 +
| 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. Particle effect + glass break sound.
 +
| RGB color as an integer (e.g. 8364543 for #7FA1FF).
 +
|-
 +
| 2008
 +
| Ender dragon destroys block
 +
|
 +
|-
 +
| 2009
 +
| Wet sponge vaporizes in nether
 +
|
 +
|-
 +
| 3000
 +
| End gateway spawn
 +
|
 +
|-
 +
| 3001
 +
| Enderdragon growl
 +
|
 +
|-
 +
| 3002
 +
| Electric spark
 +
|
 +
|-
 +
| 3003
 +
| Copper apply wax
 +
|
 +
|-
 +
| 3004
 +
| Copper remove wax
 +
|
 +
|-
 +
| 3005
 +
| Copper scrape oxidation
 +
|
 +
|}
  
Sent when the player places a block or 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…
+
Smoke directions:
  
In 1.7.3, when a player opens a door with right click, the server receives Packet 0xF (block placement, but opens door).
+
{| class="wikitable"
 +
! ID
 +
! Direction
 +
|-
 +
| 0
 +
| Down
 +
|-
 +
| 1
 +
| Up
 +
|-
 +
| 2
 +
| North
 +
|-
 +
| 3
 +
| South
 +
|-
 +
| 4
 +
| West
 +
|-
 +
| 5
 +
| East
 +
|}
 +
 
 +
==== Particle ====
 +
 
 +
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" | 0x0F
+
| rowspan="11"| 0x27
| class="col1 centeralign" | X
+
| rowspan="11"| Play
| class="col2 centeralign" | int
+
| rowspan="11"| Client
| class="col3 centeralign" | <code>32</code>
+
| Particle ID
| class="col4" | Block position
+
| {{Type|VarInt}}
|- class="row2"
+
| The particle ID listed in [[Particles]].
| class="col0 centeralign" | Y
+
|-
| class="col1 centeralign" | byte
+
| Long Distance
| class="col2 centeralign" | <code>64</code>
+
| {{Type|Boolean}}
| class="col3" | Block position
+
| If true, particle distance increases from 256 to 65536.
|- class="row3"
+
|-
| class="col0 centeralign" | Z
+
| X
| class="col1 centeralign" | int
+
| {{Type|Double}}
| class="col2 centeralign" | <code>32</code>
+
| X position of the particle.
| class="col3 leftalign" | Block position
+
|-
|- class="row4"
+
| Y
| class="col0 centeralign" | Direction
+
| {{Type|Double}}
| class="col1 centeralign" | byte
+
| Y position of the particle.
| class="col2 centeralign" | <code>3</code>
+
|-
| class="col3" | The offset to use for block/item placement (see below)
+
| Z
|- class="row5"
+
| {{Type|Double}}
| class="col0 centeralign" | Held item
+
| Z position of the particle.
| class="col1 centeralign" | [[Slot_Data|slot]]
+
|-
| class="col2 centeralign" |  
+
| Offset X
| class="col3" |
+
| {{Type|Float}}
|- class="row6"
+
| This is added to the X position after being multiplied by <code>random.nextGaussian()</code>.
! class="col0" | Total Size:
+
|-
| class="col1 rightalign" colspan="4" | 11 bytes + slot data
+
| Offset Y
|}
+
| {{Type|Float}}
 +
| This is added to the Y position after being multiplied by <code>random.nextGaussian()</code>.
 +
|-
 +
| Offset Z
 +
| {{Type|Float}}
 +
| This is added to the Z position after being multiplied by <code>random.nextGaussian()</code>.
 +
|-
 +
| Max Speed
 +
| {{Type|Float}}
 +
|
 +
|-
 +
| Particle Count
 +
| {{Type|Int}}
 +
| The number of particles to create.
 +
|-
 +
| Data
 +
| Varies
 +
| Particle data as specified in [[Particles]].
 +
|}
  
If the Block/ItemID field is greater than or equal to 0, then the last 2 fields (amount and damage) are read. Otherwise, they are not read.
+
==== Update Light ====
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:
+
Updates light levels for a chunk.  See {{Minecraft Wiki|Light}} for information on how lighting works in Minecraft.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0 leftalign" | Value
+
! State
| class="col1 centeralign" | 0
+
! Bound To
| class="col2 centeralign" | 1
+
! colspan="2"| Field Name
| class="col3 centeralign" | 2
+
! colspan="2"| Field Type
| class="col4 centeralign" | 3
+
! Notes
| class="col5 centeralign" | 4
+
|-
| class="col6 centeralign" | 5
+
| rowspan="12"| 0x28
|- class="row1"
+
| rowspan="12"| Play
! class="col0 leftalign" | Offset
+
| rowspan="12"| Client
| class="col1" | -Y
+
| colspan="2"| Chunk X
| class="col2" | +Y
+
| colspan="2"| {{Type|VarInt}}
| class="col3" | -Z
+
| Chunk coordinate (block coordinate divided by 16, rounded down)
| class="col4" | +Z
+
|-
| class="col5" | -X
+
| colspan="2"| Chunk Z
| class="col6" | +X
+
| colspan="2"| {{Type|VarInt}}
|}
+
| Chunk coordinate (block coordinate divided by 16, rounded down)
 +
|-
 +
| colspan="2"| Sky Light Mask
 +
| colspan="2"| {{Type|BitSet}}
 +
| BitSet containing bits for each section in the world + 2.  Each set bit indicates that the corresponding 16×16×16 chunk section has data in the Sky Light array below.  The least significant bit is for blocks 16 blocks to 1 block below the min world height (one section below the world), while the most significant bit covers blocks 1 to 16 blocks above the max world height (one section above the world).
 +
|-
 +
| colspan="2"| Block Light Mask
 +
| colspan="2"| {{Type|BitSet}}
 +
| BitSet containing bits for each section in the world + 2.  Each set bit indicates that the corresponding 16×16×16 chunk section has data in the Block Light array below.  The order of bits is the same as in Sky Light Mask.
 +
|-
 +
| colspan="2"| Empty Sky Light Mask
 +
| colspan="2"| {{Type|BitSet}}
 +
| BitSet containing bits for each section in the world + 2.  Each set bit indicates that the corresponding 16×16×16 chunk section has all zeros for its Sky Light data.  The order of bits is the same as in Sky Light Mask.
 +
|-
 +
| colspan="2"| Empty Block Light Mask
 +
| colspan="2"| {{Type|BitSet}}
 +
| BitSet containing bits for each section in the world + 2.  Each set bit indicates that the corresponding 16×16×16 chunk section has all zeros for its Block Light data.  The order of bits is the same as in Sky Light Mask.
 +
|-
 +
| colspan="2"| Sky Light array count
 +
| colspan="2"| {{Type|VarInt}}
 +
| Number of entries in the following array; should match the number of bits set in Sky Light Mask
 +
|-
 +
| rowspan="2"| Sky Light arrays
 +
| Length
 +
| rowspan="2"| {{Type|Array}}
 +
| {{Type|VarInt}}
 +
| Length of the following array in bytes (always 2048)
 +
|-
 +
| Sky Light array
 +
| {{Type|Byte Array}} (2048)
 +
| 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.
 +
|-
 +
| colspan="2"| Block Light array count
 +
| colspan="2"| {{Type|VarInt}}
 +
| Number of entries in the following array; should match the number of bits set in Block Light Mask
 +
|-
 +
| rowspan="2"| Block Light arrays
 +
| Length
 +
| rowspan="2"| {{Type|Array}}
 +
| {{Type|VarInt}}
 +
| Length of the following array in bytes (always 2048)
 +
|-
 +
| Block Light array
 +
| {{Type|Byte Array}} (2048)
 +
| 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.
 +
|}
  
In normal operation (ie placing a block), this packet is sent once, with the values set normally.
+
A bit will never be set in both the block light mask and the empty block light mask, though it may be present in neither of them (if the block light does not need to be updated for the corresponding chunk section).  The same applies to the sky light mask and the empty sky light mask.
  
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 such as eating food, shooting bows, using buckets, etc.
+
==== Login (play) ====
  
In a Notchian Beta client, the block or item ID corresponds to whatever the client is currently holding, and the 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. However, with the implementation of server-side inventory, a Notchian server seems to ignore the item ID, instead operating on server-side inventory information and holding selection.
+
{{Need Info|Although the number of portal cooldown ticks is included in this packet, the whole portal usage process is still dictated entirely by the server. What kind of effect does this value have on the client, if any?}}
  
Special note on using buckets:  When using buckets, the Notchian client might send two packets:  first a normal and then a special case.  The first normal packet is sent when you're looking at a block (e.g. the water you want to scoop up).  This normal packet does not appear to do anything with a Notchian server.  The second, special case packet appears to perform the action - based on current position/orientation and with a distance check - it appears that buckets can only be used within a radius of 6 units.
+
See [[Protocol Encryption]] for information on logging in.
  
=== Holding Change (0x10) ===
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="21"| 0x29
 +
| rowspan="21"| Play
 +
| rowspan="21"| Client
 +
| Entity ID
 +
| {{Type|Int}}
 +
| The player's Entity ID (EID).
 +
|-
 +
| Is hardcore
 +
| {{Type|Boolean}}
 +
|
 +
|-
 +
| Dimension Count
 +
| {{Type|VarInt}}
 +
| Size of the following array.
 +
|-
 +
| Dimension Names
 +
| {{Type|Array}} of {{Type|Identifier}}
 +
| Identifiers for all dimensions on the server.
 +
|-
 +
| Max Players
 +
| {{Type|VarInt}}
 +
| Was once used by the client to draw the player list, but now is ignored.
 +
|-
 +
| View Distance
 +
| {{Type|VarInt}}
 +
| Render distance (2-32).
 +
|-
 +
| Simulation Distance
 +
| {{Type|VarInt}}
 +
| The distance that the client will process specific things, such as entities.
 +
|-
 +
| Reduced Debug Info
 +
| {{Type|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
 +
| {{Type|Boolean}}
 +
| Set to false when the doImmediateRespawn gamerule is true.
 +
|-
 +
| Do limited crafting
 +
| {{Type|Boolean}}
 +
| Whether players can only craft recipes they have already unlocked. Currently unused by the client.
 +
|-
 +
| Dimension Type
 +
| {{Type|Identifier}}
 +
| The type of dimension in the <code>minecraft:dimension_type</code> registry, defined by the [[Protocol#Registry_Data|Registry Data]] packet.
 +
|-
 +
| Dimension Name
 +
| {{Type|Identifier}}
 +
| Name of the dimension being spawned into.
 +
|-
 +
| Hashed seed
 +
| {{Type|Long}}
 +
| First 8 bytes of the SHA-256 hash of the world's seed. Used client side for biome noise
 +
|-
 +
| Game mode
 +
| {{Type|Unsigned Byte}}
 +
| 0: Survival, 1: Creative, 2: Adventure, 3: Spectator.
 +
|-
 +
| Previous Game mode
 +
| {{Type|Byte}}
 +
| -1: Undefined (null), 0: Survival, 1: Creative, 2: Adventure, 3: Spectator. The previous game mode. Vanilla client uses this for the debug (F3 + N & F3 + F4) game mode switch. (More information needed)
 +
|-
 +
| Is Debug
 +
| {{Type|Boolean}}
 +
| True if the world is a {{Minecraft Wiki|debug mode}} world; debug mode worlds cannot be modified and have predefined blocks.
 +
|-
 +
| Is Flat
 +
| {{Type|Boolean}}
 +
| True if the world is a {{Minecraft Wiki|superflat}} world; flat worlds have different void fog and a horizon at y=0 instead of y=63.
 +
|-
 +
| Has death location
 +
| {{Type|Boolean}}
 +
| If true, then the next two fields are present.
 +
|-
 +
| Death dimension name
 +
| {{Type|Optional}} {{Type|Identifier}}
 +
| Name of the dimension the player died in.
 +
|-
 +
| Death location
 +
| {{Type|Optional}} {{Type|Position}}
 +
| The location that the player died at.
 +
|-
 +
| Portal cooldown
 +
| {{Type|VarInt}}
 +
| The number of ticks until the player can use the portal again.
 +
|}
  
Sent when the player changes the slot selection
+
==== Map Data ====
 +
 
 +
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" | 0x10
+
| rowspan="17"| 0x2A
| class="col1 centeralign" | Slot ID
+
| rowspan="17"| Play
| class="col2 centeralign" | short
+
| rowspan="17"| Client
| class="col3 centeralign" | <code>1</code>
+
| colspan="2"| Map ID
| class="col4" | The slot which the player has selected (0-8)
+
| colspan="2"| {{Type|VarInt}}
|- class="row2"
+
| Map ID of the map being modified
! class="col0" | Total Size:
+
|-
| class="col1 rightalign" colspan="4" | 3 bytes
+
| colspan="2"| Scale
|}
+
| colspan="2"| {{Type|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"| Locked
 +
| colspan="2"| {{Type|Boolean}}
 +
| True if the map has been locked in a cartography table
 +
|-
 +
| colspan="2"| Has Icons
 +
| colspan="2"| {{Type|Boolean}}
 +
|
 +
|-
 +
| colspan="2"| Icon Count
 +
| colspan="2"| {{Type|Optional}} {{Type|VarInt}}
 +
| Number of elements in the following array. Only present if previous Boolean is true.
 +
|-
 +
| rowspan="6"| Icon
 +
| Type
 +
| rowspan="6"| {{Type|Optional}} {{Type|Array}}
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| See below
 +
|-
 +
| X
 +
| {{Type|Byte}}
 +
| Map coordinates: -128 for furthest left, +127 for furthest right
 +
|-
 +
| Z
 +
| {{Type|Byte}}
 +
| Map coordinates: -128 for highest, +127 for lowest
 +
|-
 +
| Direction
 +
| {{Type|Byte}}
 +
| 0-15
 +
|-
 +
| Has Display Name
 +
| {{Type|Boolean}}
 +
|
 +
|-
 +
| Display Name
 +
| {{Type|Optional}} {{Type|Text Component}}
 +
| Only present if previous Boolean is true
 +
|-
 +
| colspan="2"| Columns
 +
| colspan="2"| {{Type|Unsigned Byte}}
 +
| Number of columns updated
 +
|-
 +
| colspan="2"| Rows
 +
| colspan="2"| {{Type|Optional}} {{Type|Unsigned Byte}}
 +
| Only if Columns is more than 0; number of rows updated
 +
|-
 +
| colspan="2"| X
 +
| colspan="2"| {{Type|Optional}} {{Type|Byte}}
 +
| Only if Columns is more than 0; x offset of the westernmost column
 +
|-
 +
| colspan="2"| Z
 +
| colspan="2"| {{Type|Optional}} {{Type|Byte}}
 +
| Only if Columns is more than 0; z offset of the northernmost row
 +
|-
 +
| colspan="2"| Length
 +
| colspan="2"| {{Type|Optional}} {{Type|VarInt}}
 +
| Only if Columns is more than 0; length of the following array
 +
|-
 +
| colspan="2"| Data
 +
| colspan="2"| {{Type|Optional}} {{Type|Array}} of {{Type|Unsigned Byte}}
 +
| Only if Columns is more than 0; see {{Minecraft Wiki|Map item format}}
 +
|}
 +
 
 +
For icons, a direction of 0 is a vertical icon and increments by 22.5&deg; (360/16).
  
=== Use Bed (0x11) ===
+
Types are based off of rows and columns in <code>map_icons.png</code>:
'''Server to Client'''<br/>
 
Associated with players using beds.
 
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
|-
! class="col0" | Packet ID
+
! Icon type
! class="col1" | Field Name
+
! Result
! class="col2" | Field Type
+
|-
! class="col3" | Example
+
| 0
! class="col4" | Notes
+
| White arrow (players)
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="5" | 0x11
+
| 1
| class="col1 centeralign" | Entity ID
+
| Green arrow (item frames)
| class="col2 centeralign" | int
+
|-
| class="col3 centeralign" | 89
+
| 2
| class="col4" | Player ID
+
| Red arrow
|- class="row2"
+
|-
| class="col0 centeralign" | ???In Bed???
+
| 3
| class="col1 centeralign" | byte
+
| Blue arrow
| class="col2 centeralign" | 0
+
|-
| class="col3" 0 Appears when players use bed
+
| 4
|- class="row1"
+
| White cross
| class="col1 centeralign" | X coordinate
+
|-
| class="col2 centeralign" | int
+
| 5
| class="col3 centeralign" | -247
+
| Red pointer
| class="col4" | Bed (headboard?) X as block coordinate
+
|-
|- class="row2"
+
| 6
| class="col0 centeralign" | Y coordinate
+
| White circle (off-map players)
| class="col1 centeralign" | byte
+
|-
| class="col2 centeralign" | 78
+
| 7
| class="col3" | Bed (headboard?) Y as block coordinate
+
| Small white circle (far-off-map players)
|- class="row1"
+
|-
| class="col1 centeralign" | Z coordinate
+
| 8
| class="col2 centeralign" | int
+
| Mansion
| class="col3 centeralign" | 128
+
|-
| class="col4" | Bed (headboard?) Z as block coordinate
+
| 9
|- class="row3"
+
| Temple
! class="col0" | Total Size:
+
|-
| class="col1 rightalign" colspan="4" | 15 bytes
+
| 10
|}
+
| White Banner
* NOTE: This Packet seems to be sent when 2 or more players are on a server, and at least one player uses a Bed.
+
|-
 +
| 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
 +
|}
  
=== Animation (0x12) ===
+
==== Merchant Offers ====
  
Sent whenever an entity should change animation.
+
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" rowspan="2" | 0x12
+
| rowspan="16"| 0x2B
| class="col1 centeralign" | EID
+
| rowspan="16"| Play
| class="col2 centeralign" | int
+
| rowspan="16"| Client
| class="col3 centeralign" | <code>55534</code>
+
| colspan="2"| Window ID
| class="col4" | Player ID
+
| colspan="2"| {{Type|VarInt}}
|- class="row2"
+
| The ID of the window that is open; this is an int rather than a byte.
| class="col0 centeralign" | Animation
+
|-
| class="col1 centeralign" | byte
+
| colspan="2"| Size
| class="col2 centeralign" | <code>1</code>
+
| colspan="2"| {{Type|VarInt}}
| class="col3" | Animation ID
+
| The number of trades in the following array.
|- class="row3"
+
|-
! class="col0" | Total Size:
+
| rowspan="10"| Trades
| class="col1 rightalign" colspan="4" | 6 bytes
+
| Input item 1
|}
+
| rowspan="10"| {{Type|Array}}
 +
| {{Type|Slot}}
 +
| The first item the player has to supply for this villager trade. The count of the item stack is the default "price" of this trade.
 +
|-
 +
| Output item
 +
| {{Type|Slot}}
 +
| The item the player will receive from this villager trade.
 +
|-
 +
| Input item 2
 +
| {{Type|Slot}}
 +
| The second item the player has to supply for this villager trade. May be an empty slot.
 +
|-
 +
| Trade disabled
 +
| {{Type|Boolean}}
 +
| True if the trade is disabled; false if the trade is enabled.
 +
|-
 +
| Number of trade uses
 +
| {{Type|Int}}
 +
| Number of times the trade has been used so far. If equal to the maximum number of trades, the client will display a red X.
 +
|-
 +
| Maximum number of trade uses
 +
| {{Type|Int}}
 +
| Number of times this trade can be used before it's exhausted.
 +
|-
 +
| XP
 +
| {{Type|Int}}
 +
| Amount of XP the villager will earn each time the trade is used.
 +
|-
 +
| Special Price
 +
| {{Type|Int}}
 +
| Can be zero or negative. The number is added to the price when an item is discounted due to player reputation or other effects.
 +
|-
 +
| Price Multiplier
 +
| {{Type|Float}}
 +
| Can be low (0.05) or high (0.2). Determines how much demand, player reputation, and temporary effects will adjust the price.
 +
|-
 +
| Demand
 +
| {{Type|Int}}
 +
| If positive, causes the price to increase. Negative values seem to be treated the same as zero.
 +
|-
 +
| colspan="2"| Villager level
 +
| colspan="2"| {{Type|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"| {{Type|VarInt}}
 +
| Total experience for this villager (always 0 for the wandering trader).
 +
|-
 +
| colspan="2"| Is regular villager
 +
| colspan="2"| {{Type|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"| {{Type|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.
 +
|}
 +
 
 +
Modifiers can increase or decrease the number of items for the first input slot. The second input slot and the output slot never change the nubmer of items. The number of items may never be less than 1, and never more than the stack size. If special price and demand are both zero, only the default price is displayed. If either is non-zero, then the adjusted price is displayed next to the crossed-out default price. The adjusted prices is calculated as follows:
 +
 
 +
Adjusted price = default price + floor(default price x multiplier x demand) + special price
  
Animation can be one of the following values:
+
[[File:1.14-merchant-slots.png|thumb|The merchant UI, for reference]]
 +
{{-}}
 +
 
 +
==== Update 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 [[#Teleport Entity|Teleport Entity]] 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"
 
{| class="wikitable"
|-
+
! Packet ID
! ID
+
! State
! Animation
+
! Bound To
|-
+
! Field Name
| 0
+
! Field Type
| No animation
+
! Notes
|-
+
|-
| 1
+
| rowspan="5"| 0x2C
| Swing arm
+
| rowspan="5"| Play
|-
+
| rowspan="5"| Client
| 2
+
| Entity ID
| Damage animation
+
| {{Type|VarInt}}
|-
+
|
| 3
+
|-
| Leave bed
+
| Delta X
|-
+
| {{Type|Short}}
| 5
+
| Change in X position as <code>(currentX * 32 - prevX * 32) * 128</code>.
| Eat food
+
|-
|-
+
| Delta Y
| 102
+
| {{Type|Short}}
| (unknown)
+
| Change in Y position as <code>(currentY * 32 - prevY * 32) * 128</code>.
|-
+
|-
| 104
+
| Delta Z
| Crouch
+
| {{Type|Short}}
|-
+
| Change in Z position as <code>(currentZ * 32 - prevZ * 32) * 128</code>.
| 105
+
|-
| Uncrouch
+
| On Ground
|}
+
| {{Type|Boolean}}
 +
|
 +
|}
 +
 
 +
==== Update Entity Position and Rotation ====
  
Only <code>1</code> (swing arm) and <code>3</code> (leave bed) is sent by notchian clients. Crouching is sent via 0x13. Damage is server-side, and so is not sent by notchian clients. See also 0x26.
+
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>)
  
=== Entity Action (0x13) ===
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="7"| 0x2D
 +
| rowspan="7"| Play
 +
| rowspan="7"| Client
 +
| Entity ID
 +
| {{Type|VarInt}}
 +
|
 +
|-
 +
| Delta X
 +
| {{Type|Short}}
 +
| Change in X position as <code>(currentX * 32 - prevX * 32) * 128</code>.
 +
|-
 +
| Delta Y
 +
| {{Type|Short}}
 +
| Change in Y position as <code>(currentY * 32 - prevY * 32) * 128</code>.
 +
|-
 +
| Delta Z
 +
| {{Type|Short}}
 +
| Change in Z position as <code>(currentZ * 32 - prevZ * 32) * 128</code>.
 +
|-
 +
| Yaw
 +
| {{Type|Angle}}
 +
| New angle, not a delta.
 +
|-
 +
| Pitch
 +
| {{Type|Angle}}
 +
| New angle, not a delta.
 +
|-
 +
| On Ground
 +
| {{Type|Boolean}}
 +
|
 +
|}
  
'''Client to Server only'''
+
==== Update Entity Rotation ====
  
Sent at least when crouching, leaving a bed, or sprinting.
+
This packet is sent by the server when an entity rotates.
To send action animation to client use 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" | 0x13
+
| rowspan="4"| 0x2E
| class="col1 centeralign" | EID
+
| rowspan="4"| Play
| class="col2 centeralign" | int
+
| rowspan="4"| Client
| class="col3 centeralign" | <code>55534</code>
+
| Entity ID
| class="col4" | Player ID
+
| {{Type|VarInt}}
|- class="row2"
+
|
| class="col0 centeralign" | Action ID
+
|-
| class="col1 centeralign" | byte
+
| Yaw
| class="col2 centeralign" | <code>1</code>
+
| {{Type|Angle}}
| class="col3" | The ID of the action, see below.
+
| New angle, not a delta.
|- class="row3"
+
|-
! class="col0" | Total Size:
+
| Pitch
| class="col1 rightalign" colspan="4" | 6 bytes
+
| {{Type|Angle}}
|}
+
| New angle, not a delta.
 +
|-
 +
| On Ground
 +
| {{Type|Boolean}}
 +
|
 +
|}
  
Action ID can be one of the following values:
+
==== Move Vehicle ====
 +
 
 +
Note that all fields use absolute positioning and do not allow for relative positioning.
  
 
{| class="wikitable"
 
{| class="wikitable"
|-
+
! Packet ID
! ID
+
! State
! Action
+
! Bound To
|-
+
! Field Name
| 1
+
! Field Type
| Crouch
+
! Notes
|-
+
|-
| 2
+
| rowspan="5"| 0x2F
| Uncrouch
+
| rowspan="5"| Play
|-
+
| rowspan="5"| Client
| 3
+
| X
| Leave bed
+
| {{Type|Double}}
|-
+
| Absolute position (X coordinate).
| 4
+
|-
| Start sprinting
+
| Y
|-
+
| {{Type|Double}}
| 5
+
| Absolute position (Y coordinate).
| Stop sprinting
+
|-
|}
+
| Z
 +
| {{Type|Double}}
 +
| Absolute position (Z coordinate).
 +
|-
 +
| Yaw
 +
| {{Type|Float}}
 +
| Absolute rotation on the vertical axis, in degrees.
 +
|-
 +
| Pitch
 +
| {{Type|Float}}
 +
| Absolute rotation on the horizontal axis, in degrees.
 +
|}
  
=== Named Entity Spawn (0x14) ===
+
==== Open Book ====
  
'''Server to Client only'''
+
Sent when a player right clicks with a signed book. This tells the client to open the book GUI.
  
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.
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x30
 +
| Play
 +
| Client
 +
| Hand
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| 0: Main hand, 1: Off hand .
 +
|}
  
Servers can, however, safely spawn player entities for players not in visible range. The client appears to handle it correctly.
+
==== Open Screen ====
  
At one point, the Notchian client was not okay with receiving player entity packets, including 0x14, that refer to its own username or EID; and would teleport to the absolute origin of the map and fall through the Void any time it received them. However, in more recent versions, it appears to handle them correctly, by spawning a new entity as directed (though future packets referring to the entity ID may be handled incorrectly).
+
This is sent to the client when it should open an inventory, such as a chest, workbench, furnace, or other container. Resending this packet with already existing window id, will update the window title and window type without closing the window.
 +
 
 +
This message is not sent to clients opening their own inventory, nor do clients inform the server in any way when doing so. From the server's perspective, the inventory is always "open" whenever no other windows are.
 +
 
 +
For horses, use [[#Open Horse Screen|Open Horse Screen]].
  
 
{| 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
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="8" | 0x14
+
| rowspan="3"| 0x31
| class="col1" | EID
+
| rowspan="3"| Play
| class="col2" | int
+
| rowspan="3"| Client
| class="col3" | <code>94453</code>
+
| Window ID
| class="col4" | Player ID
+
| {{Type|VarInt}}
|- class="row2"
+
| An identifier for the window to be displayed. Notchian server implementation is a counter, starting at 1. There can only be one window at a time; this is only used to ignore outdated packets targeting already-closed windows. Note also that the Window ID field in most other packets is only a single byte, and indeed, the Notchian server wraps around after 100.
| class="col0" | Player Name
+
|-
| class="col1" | string
+
| Window Type
| class="col2" | <code>Twdtwd</code>
+
| {{Type|VarInt}}
| class="col3" | Max length of 16
+
| The window type to use for display. Contained in the <code>minecraft:menu</code> registry; see [[Inventory]] for the different values.
|- class="row3"
+
|-
| class="col0" | X
+
| Window Title
| class="col1" | int
+
| {{Type|Text Component}}
| class="col2" | <code>784</code>
+
| The title of the window.
| 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. Note that this should be 0 for "no item", unlike -1 used in other packets. A negative value crashes clients.
 
|- class="row9"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 23 bytes + length of strings
 
|}
 
  
=== Pickup Spawn (0x15) ===
+
==== Open Sign Editor ====
  
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. (note: this means range for item vision, not range for pickup!) 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]]).
+
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 Update|Block Update]] first.
  
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.
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="2" | 0x32
 +
| rowspan="2" | Play
 +
| rowspan="2" | Client
 +
| Location
 +
| {{Type|Position}}
 +
|
 +
|-
 +
| Is Front Text
 +
| {{Type|Boolean}}
 +
| Whether the opened editor is for the front or on the back of the sign
 +
|}
 +
 
 +
==== Ping (play) ====
 +
 
 +
Packet is not used by the Notchian server. When sent to the client, client responds with a [[#Pong (play)|Pong]] packet with the same id.
  
 
{| 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
+
! Field Name
! class="col3" | Example
+
! Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="10" | 0x15
+
| 0x33
| class="col1" | EID
+
| Play
| class="col2" | int
+
| Client
| class="col3" | <code>157617</code>
+
| ID
| class="col4" | Unique entity ID
+
| {{Type|Int}}
|- class="row2"
+
|
| class="col0" | Item
+
|}
| class="col1" | short
 
| class="col2" | <code>4</code>
 
| class="col3" | The item ID
 
|- class="row3"
 
| class="col0" | Count
 
| class="col1" | byte
 
| class="col2" | <code>1</code>
 
| class="col3" | The number of items
 
|- class="row4"
 
| class="col0" | Damage/Data
 
| class="col1" | short
 
| class="col2" |
 
| class="col3" | New field in beta 1.2 update (see below)
 
|- class="row5"
 
| class="col0" | X
 
| class="col1" | int
 
| class="col2" | <code>133</code>
 
| class="col3" | Item X as Absolute Integer
 
|- class="row6"
 
| class="col0" | Y
 
| class="col1" | int
 
| 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) ===
+
==== Ping Response (play) ====
  
'''Server to Client only'''
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x34
 +
| Play
 +
| Client
 +
| Payload
 +
| {{Type|Long}}
 +
| Should be the same as sent by the client.
 +
|}
  
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). The server only checks for items to be picked up after each [[#Player_Position_.280x0B.29|Player Position]] and [[#Player_Position_.26_Look_.280x0D.29|Player Position & Look]] packet sent by the client.
+
==== Place Ghost Recipe ====
  
 +
Response to the serverbound packet ([[#Place Recipe|Place Recipe]]), 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" rowspan="2" | 0x16
+
| rowspan="2"| 0x35
| class="col1 centeralign" | Collected EID
+
| rowspan="2"| Play
| class="col2 centeralign" | int
+
| rowspan="2"| Client
| class="col3 centeralign" | <code>38</code>
+
| Window ID
| class="col4 leftalign" |
+
| {{Type|Byte}}
|- class="row2"
+
|
| class="col0 centeralign" | Collector EID
+
|-
| class="col1 centeralign" | int
+
| Recipe
| class="col2 centeralign" | <code>20</code>
+
| {{Type|Identifier}}
| class="col3 leftalign" |
+
| A recipe ID.
|- class="row3"
+
|}
! class="col0" | Total Size:
+
 
| class="col1 rightalign" colspan="4" | 9 bytes
+
==== Player Abilities (clientbound) ====
|}
 
  
=== Add Object/Vehicle (0x17) ===
+
The latter 2 floats are used to indicate the flying speed and field of view respectively, while the first byte is used to determine the value of 4 booleans.
  
'''Server to Client only'''
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="3"| 0x36
 +
| rowspan="3"| Play
 +
| rowspan="3"| Client
 +
| Flags
 +
| {{Type|Byte}}
 +
| Bit field, see below.
 +
|-
 +
| Flying Speed
 +
| {{Type|Float}}
 +
| 0.05 by default.
 +
|-
 +
| Field of View Modifier
 +
| {{Type|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 [[#Update Attributes|Update Attributes]] packet, which defaults to 0.1 for players.
 +
|}
  
Sent by the server when an Object/Vehicle is created.
+
About the flags:
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
|-
! class="col0" | Packet ID
+
! Field
! class="col1" | Field Name
+
! Bit
! class="col2" | Field Type
+
|-
! class="col3" | Example
+
| Invulnerable
! class="col4" | Notes
+
| 0x01
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="9" | 0x17
+
| Flying
| class="col1 centeralign" | EID
+
| 0x02
| class="col2 centeralign" | int
+
|-
| class="col3 centeralign" | <code>62</code>
+
| Allow Flying
| class="col4" | Entity ID of the Object
+
| 0x04
|- class="row2"
+
|-
| class="col0 centeralign" | Type
+
| Creative Mode (Instant Break)
| class="col1 centeralign" | byte
+
| 0x08
| class="col2 centeralign" | <code>11</code>
+
|}
| class="col3" | The type of object (see [[Entities#Objects]])
+
 
|- class="row3"
+
==== Player Chat Message ====
| class="col0 centeralign" | X
+
 
| class="col1 centeralign" | int
+
Sends the client a chat message from a player.  
| class="col2 centeralign" | <code>16080</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>2299</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>592</code>
 
| class="col3" | The Absolute Integer Z Position of the object
 
|- class="row6"
 
| class="col0 centeralign" | Fireball thrower's entity ID
 
| class="col1 centeralign" | int
 
| class="col2 centeralign" | <code>0</code>
 
| class="col3" | If this is bigger than 0, this is a fireball and the next 3 fields are sent.
 
|- class="row7"
 
| class="col0 centeralign" | Speed X
 
| class="col1 centeralign" | short
 
| class="col2 centeralign" | <code>0</code>
 
| class="col3" | Not sent if the thrower entity ID is 0. The speed of this fireball along the X axis.
 
|- class="row5"
 
| class="col0 centeralign" | Speed Y
 
| class="col1 centeralign" | short
 
| class="col2 centeralign" | <code>0</code>
 
| class="col3" | Not sent if the thrower entity ID is 0. The speed of this fireball along the Y axis.
 
|- class="row5"
 
| class="col0 centeralign" | Speed Z
 
| class="col1 centeralign" | short
 
| class="col2 centeralign" | <code>0</code>
 
| class="col3" | Not sent if the thrower entity ID is 0. The speed of this fireball along the Z axis.
 
|- class="row6"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 22 or 28 bytes
 
|}
 
  
=== Mob Spawn (0x18) ===
+
Currently a lot is unknown about this packet, blank descriptions are for those that are unknown
  
'''Server to Client only'''
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Sector
 +
! colspan="2"| Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="18"| 0x37
 +
| rowspan="18"| Play
 +
| rowspan="18"| Client
 +
| rowspan="4"| Header
 +
| colspan="2"| Sender
 +
| {{Type|UUID}}
 +
| Used by the Notchian client for the disableChat launch option. Setting both longs to 0 will always display the message regardless of the setting.
 +
|-
 +
| colspan="2"| Index
 +
| {{Type|VarInt}}
 +
|
 +
|-
 +
| colspan="2"| Message Signature Present
 +
| {{Type|Boolean}}
 +
| States if a message signature is present
 +
|-
 +
| colspan="2"| Message Signature bytes
 +
| {{Type|Optional}} {{Type|Byte Array}} (256)
 +
| Only present if <code>Message Signature Present</code> is true. Cryptography, the signature consists of the Sender UUID, Session UUID from the [[#Player Session|Player Session]] packet, Index, Salt, Timestamp in epoch seconds, the length of the original chat content, the original content itself, the length of Previous Messages, and all of the Previous message signatures. These values are hashed with [https://en.wikipedia.org/wiki/SHA-2 SHA-256] and signed using the [https://en.wikipedia.org/wiki/RSA_(cryptosystem) RSA] cryptosystem. Modifying any of these values in the packet will cause this signature to fail. This buffer is always 256 bytes long and it is not length-prefixed.
 +
|-
 +
| rowspan="3"| Body
 +
| colspan="2"| Message
 +
| {{Type|String}} (256)
 +
| Raw (optionally) signed sent message content.
 +
This is used as the <code>content</code> parameter when formatting the message on the client.
 +
|-
 +
| colspan="2"| Timestamp
 +
| {{Type|Long}}
 +
| Represents the time the message was signed as milliseconds since the [https://en.wikipedia.org/wiki/Unix_time epoch], used to check if the message was received within 2 minutes of it being sent.
 +
|-
 +
| colspan="2"| Salt
 +
| {{Type|Long}}
 +
| Cryptography, used for validating the message signature.
 +
|-
 +
| rowspan="3"| Previous Messages
 +
| colspan="2"| Total Previous Messages
 +
| {{Type|VarInt}}
 +
| The maximum length is 20 in Notchian client.
 +
|
 +
|-
 +
| rowspan="2"| {{Type|Array}} (20)
 +
| Message ID
 +
| {{Type|VarInt}}
 +
| The message Id + 1, used for validating message signature. The next field is present only when value of this field is equal to 0.
 +
|-
 +
| Signature
 +
| {{Type|Optional}} {{Type|Byte Array}} (256)
 +
| The previous message's signature. Contains the same type of data as <code>Message Signature bytes</code> (256 bytes) above. Not length-prefxied.
 +
|-
 +
| rowspan="4"| Other
 +
| colspan="2"| Unsigned Content Present
 +
| {{Type|Boolean}}
 +
| True if the next field is present
 +
|-
 +
| colspan="2"| Unsigned Content
 +
| {{Type|Optional}} {{Type|Text Component}}
 +
|
 +
|-
 +
| colspan="2"| Filter Type
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| If the message has been filtered
 +
|-
 +
| colspan="2"| Filter Type Bits
 +
| {{Type|Optional}} {{Type|BitSet}}
 +
| Only present if the Filter Type is Partially Filtered. Specifies the indexes at which characters in the original message string should be replaced with the <code>#</code> symbol (i.e. filtered) by the Notchian client
 +
|-
 +
| rowspan="4"| Chat Formatting
 +
| colspan="2"| Chat Type
 +
| {{Type|VarInt}}
 +
| The type of chat in the <code>minecraft:chat_type</code> registry, defined by the [[Protocol#Registry_Data|Registry Data]] packet.
 +
|-
 +
| colspan="2"| Sender Name
 +
| {{Type|Text Component}}
 +
| The name of the one sending the message, usually the sender's display name.
 +
This is used as the <code>sender</code> parameter when formatting the message on the client.
 +
|-
 +
| colspan="2"| Has Target Name
 +
| {{Type|Boolean}}
 +
| True if target name is present.
 +
|-
 +
| colspan="2"| Target Name
 +
| {{Type|Optional}} {{Type|Text Component}}
 +
| The name of the one receiving the message, usually the receiver's display name. Only present if previous boolean is true.
 +
This is used as the <code>target</code> parameter when formatting the message on the client.
 +
|}
 +
[[File:MinecraftChat.drawio4.png|thumb|Player Chat Handling Logic]]
  
Sent by the server when a Mob Entity is Spawned
+
Filter Types:
 +
 
 +
The filter type mask should NOT be specified unless partially filtered is selected
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! ID
! class="col0" | Packet ID
+
! Name
! class="col1" | Field Name
+
! Description
! class="col2" | Field Type
+
|-
! class="col3" | Example
+
| 0
! class="col4" | Notes
+
| PASS_THROUGH
|- class="row1"
+
| Message is not filtered at all
| class="col0 centeralign" rowspan="9" | 0x18
+
|-
| class="col1 centeralign" | EID
+
| 1
| class="col2 centeralign" | int
+
| FULLY_FILTERED
| class="col3 centeralign" | <code>446</code>
+
| Message is fully filtered
| class="col4" | Entity ID
+
|-
|- class="row2"
+
| 2
| class="col0 centeralign" | Type
+
| PARTIALLY_FILTERED
| class="col1 centeralign" | byte
+
| Only some characters in the message are filtered
| class="col2 centeralign" | <code>91</code>
+
|}
| class="col3" | The type of mob. See [[Entities#Mobs]]
 
|- 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 yaw in steps of 2π/256
 
|- class="row7"
 
| class="col0 centeralign" | Pitch
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>0</code>
 
| class="col3" | The pitch in steps of 2π/256
 
|- class="row8"
 
| class="col0 centeralign" | Head Yaw
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" |
 
| class="col3" | Head yaw in steps of 2π/256
 
|- class="row9"
 
| class="col0 centeralign" | Metadata
 
| class="col1 centeralign" | Metadata
 
| class="col2 centeralign" | <code>127</code>
 
| class="col3" | Varies by mob, see [[Entities]]
 
|- class="row10"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 21 bytes + Metadata (at least 1)
 
|}
 
  
=== Entity: Painting (0x19) ===
+
==== End Combat ====
  
This packet shows location, name, and type of painting.
+
Unused by the Notchian client.  This data was once used for twitch.tv metadata circa 1.8.
  
 
{| 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"| 0x38
| class="col1 centeralign" | Entity ID
+
| rowspan="1"| Play
| class="col2 centeralign" | int
+
| rowspan="1"| Client
| class="col3 centeralign" | <code>0x00000326</code>
+
| Duration
| class="col4 centeralign" | Unique entity ID
+
| {{Type|VarInt}}
|- class="row2"
+
| Length of the combat in ticks.
| class="col1 centeralign" | Title
+
|}
| class="col2 centeralign" | string
 
| class="col3 centeralign" | <code>Creepers</code>
 
| class="col4 centeralign" | Name of the painting; max length 13 (length of "SkullAndRoses")
 
|- class="row3"
 
| class="col1 centeralign" | X
 
| class="col2 centeralign" | int
 
| class="col3 centeralign" | <code>50</code>
 
| class="col4 centeralign" | Center X coordinate
 
|- class="row4"
 
| class="col1 centeralign" | Y
 
| class="col2 centeralign" | int
 
| class="col3 centeralign" | <code>66</code>
 
| class="col4 centeralign" | Center Y coordinate
 
|- class="row5"
 
| class="col1 centeralign" | Z
 
| class="col2 centeralign" | int
 
| class="col3 centeralign" | <code>-50</code>
 
| class="col4 centeralign" | Center Z coordinate
 
|- class="row6"
 
| class="col1 centeralign" | Direction
 
| class="col2 centeralign" | int
 
| class="col3 centeralign" | <code>0</code>
 
| class="col4 centeralign" | Direction the painting faces (0 -z, 1 -x, 2 +z, 3 +x)
 
|- class="row7"
 
! class="col1" | Total Size:
 
| class="col2 rightalign" colspan="4" | 23 bytes + length of strings
 
|}
 
  
Calculating the center of an image: given a (width x height) grid of cells, with (0, 0) being the top left corner, the center is (max(0, width / 2 - 1), height / 2). E.g.
+
==== Enter Combat ====
  
2x1 (1, 0)
+
Unused by the Notchian client.  This data was once used for twitch.tv metadata circa 1.8.
4x4 (1, 2)
 
  
=== Experience Orb (0x1A) ===
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="1"| 0x39
 +
| rowspan="1"| Play
 +
| rowspan="1"| Client
 +
| colspan="3"| ''no fields''
 +
|}
  
'''Server to Client only'''
+
==== Combat Death ====
  
Spawns a one or more experience orbs. Co-ordinates are in absolute units.
+
Used to send a respawn screen.
  
 
{| 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" | 0x1A
+
| rowspan="2"| 0x3A
| class="col1 centeralign" | Entity ID
+
| rowspan="2"| Play
| class="col2 centeralign" | int
+
| rowspan="2"| Client
| class="col3 centeralign" | 105668
+
| Player ID
| class="col4" |
+
| {{Type|VarInt}}
|- class="row2"
+
| Entity ID of the player that died (should match the client's entity ID).
| class="col1 centeralign" | x
+
|-
| class="col2 centeralign" | int
+
| Message
| class="col3 centeralign" | -1143
+
| {{Type|Text Component}}
| class="col4" |
+
| The death message.
|- class="row3"
+
|}
| class="col1 centeralign" | y
+
 
| class="col2 centeralign" | int
+
==== Player Info Remove ====
| class="col3 centeralign" | 1952
 
| class="col4" |
 
|- class="row4"
 
| class="col1 centeralign" | z
 
| class="col2 centeralign" | int
 
| class="col3 centeralign" | 1166
 
| class="col4" |
 
|- class="row5"
 
| class="col1 centeralign" | count
 
| class="col2 centeralign" | short
 
| class="col3 centeralign" | 7
 
| class="col4" |
 
|- class="row4"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 19 bytes
 
|}
 
  
=== Entity Velocity (0x1C) ===
+
Used by the server to remove players from the player list.
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);
+
{| class="wikitable"
for example, -1343 would move (-1343 / 32000) = -0.04196875 blocks per tick (or -0.20984375 blocks per second).
+
! Packet ID
 +
! State
 +
! Bound To
 +
! colspan="2"| Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="2"| 0x3B
 +
| rowspan="2"| Play
 +
| rowspan="2"| Client
 +
| colspan="2"| Number of Players
 +
| {{Type|VarInt}}
 +
| Number of elements in the following array.
 +
|-
 +
| Player
 +
| Player Id
 +
| {{Type|Array}} of {{Type|UUID}}
 +
| UUIDs of players to remove.
 +
|}
  
Each axis' velocity is capped between -0.9 and 0.9 blocks per tick (packet values -28800 to 28800).
+
==== Player Info Update ====
  
(This packet data values are not fully verified)
+
Sent by the server to update the user list (<tab> in the client).
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! colspan="2"| Field Name
 +
! colspan="2"| Field Type
 +
! Notes
 +
|-
 +
| rowspan="4"| 0x3C
 +
| rowspan="4"| Play
 +
| rowspan="4"| Client
 +
| colspan="2"| Actions
 +
| colspan="2"| {{Type|Byte}}
 +
| Determines what actions are present.
 +
|-
 +
| colspan="2"| Number Of Players
 +
| colspan="2"| {{Type|VarInt}}
 +
| Number of elements in the following array.
 +
|-
 +
| rowspan="2" | Players
 +
| UUID
 +
| rowspan="2" | {{Type|Array}}
 +
| {{Type|UUID}}
 +
| The player UUID
 +
|-
 +
| Player Actions
 +
| {{Type|Array}} of [[#player-info:player-actions|Player&nbsp;Actions]]
 +
| The length of this array is determined by the number of [[#player-info:player-actions|Player Actions]] that give a non-zero value when applying its mask to the actions flag. For example given the decimal number 5, binary 00000101. The masks 0x01 and 0x04 would return a non-zero value, meaning the Player Actions array would include two actions: Add Player and Update Game Mode.
 +
|}
 +
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
|+ id="player-info:player-actions" | Player Actions
! class="col0" | Packet ID
+
! Action
! class="col1" | Field Name
+
! Mask
! class="col2" | Field Type
+
! colspan="2" | Field Name
! class="col3" | Example
+
! colspan="2" | Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan="4" | 0x1C
+
| rowspan="6" | Add Player
| class="col1 centeralign" | Entity ID
+
| rowspan="6" | 0x01
| class="col2 centeralign" | int
+
| colspan="2" | Name
| class="col3 centeralign" | <code>1805</code>
+
| colspan="2" | {{Type|String (16)}}
| class="col4" |
+
|-
The entity ID
+
| colspan="2" | Number Of Properties
|- class="row2"
+
| colspan="2" | {{Type|VarInt}}
| class="col0 centeralign" | Velocity X
+
| Number of elements in the following array.
| class="col1 centeralign" | short
+
|-
| class="col2 centeralign" | <code>-1343</code>
+
| rowspan="4" | Property
| class="col3" |
+
| Name
Velocity on the X axis
+
| rowspan="4"| {{Type|Array}}
|- class="row3"
+
| {{Type|String (32767)}}
| class="col0 centeralign" | Velocity Y
+
|
| class="col1 centeralign" | short
+
|-
| class="col2 centeralign" | <code>0</code>
+
| Value
| class="col3" |
+
| {{Type|String (32767)}}
Velocity on the Y axis
+
|
|- class="row4"
+
|-
| class="col0 centeralign" | Velocity Z
+
| Is Signed
| class="col1 centeralign" | short
+
| {{Type|Boolean}}
| class="col2 centeralign" | <code>0</code>
+
|
| class="col3" |
+
|-
Velocity on the Z axis
+
| Signature
|- class="row5"
+
| {{Type|Optional}} {{Type|String (32767)}}
! class="col0" | Total Size:
+
| Only if Is Signed is true.
| class="col1 rightalign" colspan="4" | 11 bytes
+
|-
|}
+
| rowspan="7" | Initialize Chat
 +
| rowspan="7" | 0x02
 +
| colspan="2" | Has Signature Data
 +
| colspan="2" | {{Type|Boolean}}
 +
|-
 +
| colspan="2" | Chat session ID
 +
| colspan="2" | {{Type|UUID}}
 +
| Only sent if Has Signature Data is true.
 +
|-
 +
| colspan="2" | Public key expiry time
 +
| colspan="2" | {{Type|Long}}
 +
| Key expiry time, as a UNIX timestamp in milliseconds. Only sent if Has Signature Data is true.
 +
|-
 +
| colspan="2" | Encoded public key size
 +
| colspan="2" | {{Type|VarInt}}
 +
| Size of the following array. Only sent if Has Signature Data is true. Maximum length is 512 bytes.
 +
|-
 +
| colspan="2" | Encoded public key
 +
| colspan="2" | {{Type|Byte Array}} (512)
 +
| The player's public key, in bytes. Only sent if Has Signature Data is true.
 +
|-
 +
| colspan="2" | Public key signature size
 +
| colspan="2" | {{Type|VarInt}}
 +
| Size of the following array. Only sent if Has Signature Data is true. Maximum length is 4096 bytes.
 +
|-
 +
| colspan="2" | Public key signature
 +
| colspan="2" | {{Type|Byte Array}} (4096)
 +
| The public key's digital signature. Only sent if Has Signature Data is true.
 +
|-
 +
| Update Game Mode
 +
| 0x04
 +
| colspan="2" | Game Mode
 +
| colspan="2" | {{Type|VarInt}}
 +
|-
 +
| Update Listed
 +
| 0x08
 +
| colspan="2" | Listed
 +
| colspan="2" | {{Type|Boolean}}
 +
| Whether the player should be listed on the player list.
 +
|-
 +
| Update Latency
 +
| 0x10
 +
| colspan="2" | Ping
 +
| colspan="2" | {{Type|VarInt}}
 +
| Measured in milliseconds.
 +
|-
 +
| rowspan="2" | Update Display Name
 +
| rowspan="2" | 0x20
 +
| colspan="2" | Has Display Name
 +
| colspan="2" | {{Type|Boolean}}
 +
|-
 +
| colspan="2" | Display Name
 +
| colspan="2" | {{Type|Optional}} {{Type|Text Component}}
 +
| Only sent if Has Display Name is true.
 +
|}
  
=== Destroy Entity (0x1D) ===
+
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.
  
'''Server to Client only'''
+
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.
  
Sent by the server when an Entity is to be destroyed on the client.
+
==== Look At ====
 +
 
 +
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" | 0x1D
+
| rowspan="8"| 0x3D
| class="col1 centeralign" | EID
+
| rowspan="8"| Play
| class="col2 centeralign" | int
+
| rowspan="8"| Client
| class="col3 centeralign" | <code>446</code>
+
|-
| class="col4 centeralign" | Entity ID
+
| Feet/eyes
|- class="row2"
+
| {{Type|VarInt}} {{Type|Enum}}
! class="col0" | Total Size:
+
| Values are feet=0, eyes=1.  If set to eyes, aims using the head position; otherwise aims using the feet position.
| class="col1 rightalign" colspan="4" | 5 bytes
+
|-
|}
+
| Target x
 +
| {{Type|Double}}
 +
| x coordinate of the point to face towards.
 +
|-
 +
| Target y
 +
| {{Type|Double}}
 +
| y coordinate of the point to face towards.
 +
|-
 +
| Target z
 +
| {{Type|Double}}
 +
| z coordinate of the point to face towards.
 +
|-
 +
| Is entity
 +
| {{Type|Boolean}}
 +
| If true, additional information about an entity is provided.
 +
|-
 +
| Entity ID
 +
| {{Type|Optional}} {{Type|VarInt}}
 +
| Only if is entity is true &mdash; the entity to face towards.
 +
|-
 +
| Entity feet/eyes
 +
| {{Type|Optional}} {{Type|VarInt}} {{Type|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.
 +
 
 +
==== Synchronize Player Position ====
  
=== Entity (0x1E) ===
+
Teleports the client, e.g. during login, when using an ender pearl, in response to invalid move packets, etc.
  
'''Server to Client only'''
+
Due to latency, the server may receive outdated movement packets sent before the client was aware of the teleport. To account for this, the server ignores all movement packets from the client until a [[#Confirm Teleportation|Confirm Teleportation]] packet with an ID matching the one sent in the teleport packet is received.
  
Most entity-related packets are subclasses of this packet. When sent from the server to the client, it may initialize the entry.
+
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.
  
For player entities, either this packet or any move/look packet is sent every game tick.
+
Pitch is measured in degrees, where 0 is looking straight ahead, -90 is looking straight up, and 90 is looking straight down.
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="7"| 0x3E
| class="col1 centeralign" | EID
+
| rowspan="7"| Play
| class="col2 centeralign" | int
+
| rowspan="7"| Client
| class="col3 centeralign" | <code>446</code>
+
| X
| class="col4 centeralign" | Entity ID
+
| {{Type|Double}}
|- class="row2"
+
| Absolute or relative position, depending on Flags.
! class="col0" | Total Size:
+
|-
| class="col1 rightalign" colspan="4" | 5 bytes
+
| Y
|}
+
| {{Type|Double}}
 +
| Absolute or relative position, depending on Flags.
 +
|-
 +
| Z
 +
| {{Type|Double}}
 +
| Absolute or relative position, depending on Flags.
 +
|-
 +
| Yaw
 +
| {{Type|Float}}
 +
| Absolute or relative rotation on the X axis, in degrees.
 +
|-
 +
| Pitch
 +
| {{Type|Float}}
 +
| Absolute or relative rotation on the Y axis, in degrees.
 +
|-
 +
| Flags
 +
| {{Type|Byte}}
 +
| Reference the Flags table below. When the value of the this byte masked is zero the field is absolute, otherwise relative.
 +
|-
 +
| Teleport ID
 +
| {{Type|VarInt}}
 +
| Client should confirm this packet with [[#Confirm Teleportation|Confirm Teleportation]] containing the same Teleport ID.
 +
|}
  
=== Entity Relative Move (0x1F) ===
+
{| class="wikitable"
 +
|+ Flags
 +
|-
 +
! Field
 +
! Hex Mask
 +
|-
 +
| X
 +
| 0x01
 +
|-
 +
| Y
 +
| 0x02
 +
|-
 +
| Z
 +
| 0x04
 +
|-
 +
| Y_ROT (Pitch)
 +
| 0x08
 +
|-
 +
| X_ROT (Yaw)
 +
| 0x10
 +
|}
  
'''Server to Client only'''
+
==== Update Recipe Book ====
  
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="14"| 0x3F
 +
| rowspan="14"| Play
 +
| rowspan="14"| Client
 +
|-
 +
| Action
 +
| {{Type|VarInt}}
 +
| 0: init, 1: add, 2: remove.
 +
|-
 +
| Crafting Recipe Book Open
 +
| {{Type|Boolean}}
 +
| If true, then the crafting recipe book will be open when the player opens its inventory.
 +
|-
 +
| Crafting Recipe Book Filter Active
 +
| {{Type|Boolean}}
 +
| If true, then the filtering option is active when the players opens its inventory.
 +
|-
 +
| Smelting Recipe Book Open
 +
| {{Type|Boolean}}
 +
| If true, then the smelting recipe book will be open when the player opens its inventory.
 +
|-
 +
| Smelting Recipe Book Filter Active
 +
| {{Type|Boolean}}
 +
| If true, then the filtering option is active when the players opens its inventory.
 +
|-
 +
| Blast Furnace Recipe Book Open
 +
| {{Type|Boolean}}
 +
| If true, then the blast furnace recipe book will be open when the player opens its inventory.
 +
|-
 +
| Blast Furnace Recipe Book Filter Active
 +
| {{Type|Boolean}}
 +
| If true, then the filtering option is active when the players opens its inventory.
 +
|-
 +
| Smoker Recipe Book Open
 +
| {{Type|Boolean}}
 +
| If true, then the smoker recipe book will be open when the player opens its inventory.
 +
|-
 +
| Smoker Recipe Book Filter Active
 +
| {{Type|Boolean}}
 +
| If true, then the filtering option is active when the players opens its inventory.
 +
|-
 +
| Array size 1
 +
| {{Type|VarInt}}
 +
| Number of elements in the following array.
 +
|-
 +
| Recipe IDs
 +
| {{Type|Array}} of {{Type|Identifier}}
 +
|
 +
|-
 +
| Array size 2
 +
| {{Type|Optional}} {{Type|VarInt}}
 +
| Number of elements in the following array, only present if mode is 0 (init).
 +
|-
 +
| Recipe IDs
 +
| {{Type|Optional}} {{Type|Array}} of {{Type|Identifier}}
 +
| Only present if mode is 0 (init)
 +
|}
 +
Action:
 +
* 0 (init) = All the recipes in list 1 will be tagged as displayed, and all the recipes in list 2 will be added to the recipe book. Recipes that aren't tagged will be shown in the notification.
 +
* 1 (add) = All the recipes in the list are added to the recipe book and their icons will be shown in the notification.
 +
* 2 (remove) = Remove all the recipes in the list. This allows them to be re-displayed when they are re-added.
  
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.
+
==== Remove Entities ====
  
 +
Sent by the server when an entity 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="4" | 0x1F
+
| rowspan="2"| 0x40
| class="col1 centeralign" | EID
+
| rowspan="2"| Play
| class="col2 centeralign" | int
+
| rowspan="2"| Client
| class="col3 centeralign" | <code>459</code>
+
| Count
| class="col4" | Entity ID
+
| {{Type|VarInt}}
|- class="row2"
+
| Number of elements in the following array.
| class="col0 centeralign" | dX
+
|-
| class="col1 centeralign" | byte
+
| Entity IDs
| class="col2 centeralign" | <code>1</code>
+
| {{Type|Array}} of {{Type|VarInt}}
| class="col3" | X axis Relative movement as an Absolute Integer
+
| The list of entities to destroy.
|- 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) ===
+
==== Remove Entity Effect ====
  
'''Server to Client only'''
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="2"| 0x41
 +
| rowspan="2"| Play
 +
| rowspan="2"| Client
 +
| Entity ID
 +
| {{Type|VarInt}}
 +
|
 +
|-
 +
| Effect ID
 +
| {{Type|VarInt}}
 +
| See {{Minecraft Wiki|Status effect#Effect list|this table}}.
 +
|}
  
This packet is sent by the server when an entity rotates.  Example: "Yaw" field 64 means a 90 degree turn.
+
==== Reset Score ====
 +
 
 +
This is sent to the client when it should remove a scoreboard item.
  
 
{| 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="3"| 0x42
| class="col1 centeralign" | EID
+
| rowspan="3"| Play
| class="col2 centeralign" | int
+
| rowspan="3"| Client
| class="col3 centeralign" | <code>459</code>
+
| Entity Name
| class="col4" | Entity ID
+
| {{Type|String}} (32767)
|- class="row2"
+
| The entity whose score this is. For players, this is their username; for other entities, it is their UUID.
| class="col0 centeralign" | Yaw
+
|-
| class="col1 centeralign" | byte
+
| Has Objective Name
| class="col2 centeralign" | <code>126</code>
+
| {{Type|Boolean}}
| class="col3" | The X Axis rotation as a fraction of 360
+
| Whether the score should be removed for the specified objective, or for all of them.
|- class="row3"
+
|-
| class="col0 centeralign" | Pitch
+
| Objective Name
| class="col1 centeralign" | byte
+
| {{Type|Optional}} {{Type|String}} (32767)
| class="col2 centeralign" | <code>0</code>
+
| The name of the objective the score belongs to. Only present if the previous field is true.
| class="col3" | The Y Axis rotation as a fraction of 360
+
|}
|- class="row4"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 7 bytes
 
|}
 
  
=== Entity Look and Relative Move (0x21) ===
+
==== Remove Resource Pack (play) ====
  
'''Server to Client only'''
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="2"| 0x43
 +
| rowspan="2"| Play
 +
| rowspan="2"| Client
 +
| Has UUID
 +
| {{Type|Boolean}}
 +
| Whether a specific resource pack should be removed, or all of them.
 +
|-
 +
| UUID
 +
| {{Type|Optional}} {{Type|UUID}}
 +
| The UUID of the resource pack to be removed. Only present if the previous field is true.
 +
|}
  
This packet is sent by the server when an entity rotates and moves.
+
==== Add Resource Pack (play) ====
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"
+
! 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" | 0x21
+
| rowspan="6"| 0x44
| class="col1 centeralign" | EID
+
| rowspan="6"| Play
| class="col2 centeralign" | int
+
| rowspan="6"| Client
| class="col3 centeralign" | <code>459</code>
+
| UUID
| class="col4" | Entity ID
+
| {{Type|UUID}}
|- class="row2"
+
| The unique identifier of the resource pack.
| class="col0 centeralign" | dX
+
|-
| class="col1 centeralign" | byte
+
| URL
| class="col2 centeralign" | <code>1</code>
+
| {{Type|String}} (32767)
| class="col3" | X axis Relative movement as an Absolute Integer
+
| The URL to the resource pack.
|- class="row3"
+
|-
| class="col0 centeralign" | dY
+
| Hash
| class="col1 centeralign" | byte
+
| {{Type|String}} (40)
| class="col2 centeralign" | <code>-7</code>
+
| A 40 character hexadecimal, case-insensitive [[wikipedia:SHA-1|SHA-1]] hash of the resource pack file.<br />If it's not a 40 character hexadecimal string, the client will not use it for hash verification and likely waste bandwidth.
| class="col3" | Y axis Relative movement as an Absolute Integer
+
|-
|- class="row4"
+
| Forced
| class="col0 centeralign" | dZ
+
| {{Type|Boolean}}
| class="col1 centeralign" | byte
+
| The Notchian client will be forced to use the resource pack from the server. If they decline they will be kicked from the server.
| class="col2 centeralign" | <code>5</code>
+
|-
| class="col3" | Z axis Relative movement as an Absolute Integer
+
| Has Prompt Message
|- class="row5"
+
| {{Type|Boolean}}
| class="col0 centeralign" | Yaw
+
| Whether a custom message should be used on the resource pack prompt.
| class="col1 centeralign" | byte
+
|-
| class="col2 centeralign" | <code>126</code>
+
| Prompt Message
| class="col3" | The X Axis rotation as a fraction of 360
+
| {{Type|Optional}} {{Type|Text Component}}
|- class="row6"
+
| This is shown in the prompt making the client accept or decline the resource pack. Only present if the previous field is true.
| 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" | 10 bytes
 
|}
 
  
=== Entity Teleport (0x22) ===
+
==== Respawn ====
  
'''Server to Client only'''
+
{{Need Info|Although the number of portal cooldown ticks is included in this packet, the whole portal usage process is still dictated entirely by the server. What kind of effect does this value have on the client, if any?}}
  
This packet is sent by the server when an entity moves more than 4 blocks.
+
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="6" | 0x22
+
| rowspan="12"| 0x45
| class="col1 centeralign" | EID
+
| rowspan="12"| Play
| class="col2 centeralign" | int
+
| rowspan="12"| Client
| class="col3 centeralign" | <code>459</code>
+
| Dimension Type
| class="col4" | Entity ID
+
| {{Type|Identifier}}
|- class="row2"
+
| The type of dimension in the <code>minecraft:dimension_type</code> registry, defined by the [[Protocol#Registry_Data|Registry Data]] packet.
| class="col0 centeralign" | X
+
|-
| class="col1 centeralign" | int
+
| Dimension Name
| class="col2 centeralign" | <code>14162</code>
+
| {{Type|Identifier}}
| class="col3" | X axis position as an Absolute Integer
+
| Name of the dimension being spawned into.
|- class="row3"
+
|-
| class="col0 centeralign" | Y
+
| Hashed seed
| class="col1 centeralign" | int
+
| {{Type|Long}}
| class="col2 centeralign" | <code>2176</code>
+
| First 8 bytes of the SHA-256 hash of the world's seed. Used client side for biome noise
| class="col3" | Y axis position as an Absolute Integer
+
|-
|- class="row4"
+
| Game mode
| class="col0 centeralign" | Z
+
| {{Type|Unsigned Byte}}
| class="col1 centeralign" | int
+
| 0: Survival, 1: Creative, 2: Adventure, 3: Spectator.
| class="col2 centeralign" | <code>1111</code>
+
|-
| class="col3" | Z axis position as an Absolute Integer
+
| Previous Game mode
|- class="row5"
+
| {{Type|Byte}}
| class="col0 centeralign" | Yaw
+
| -1: Undefined (null), 0: Survival, 1: Creative, 2: Adventure, 3: Spectator. The previous game mode. Vanilla client uses this for the debug (F3 + N & F3 + F4) game mode switch. (More information needed)
| class="col1 centeralign" | byte
+
|-
| class="col2 centeralign" | <code>126</code>
+
| Is Debug
| class="col3" | The X Axis rotation as a fraction of 360
+
| {{Type|Boolean}}
|- class="row6"
+
| True if the world is a {{Minecraft Wiki|debug mode}} world; debug mode worlds cannot be modified and have predefined blocks.
| class="col0 centeralign" | Pitch
+
|-
| class="col1 centeralign" | byte
+
| Is Flat
| class="col2 centeralign" | <code>0</code>
+
| {{Type|Boolean}}
| class="col3" | The Y Axis rotation as a fraction of 360
+
| True if the world is a {{Minecraft Wiki|superflat}} world; flat worlds have different void fog and a horizon at y=0 instead of y=63.
|- class="row7"
+
|-
! class="col0" | Total Size:
+
| Has death location
| class="col1 rightalign" colspan="4" | 19 bytes
+
| {{Type|Boolean}}
|}
+
| If true, then the next two fields are present.
 +
|-
 +
| Death dimension Name
 +
| {{Type|Optional}} {{Type|Identifier}}
 +
| Name of the dimension the player died in.
 +
|-
 +
| Death location
 +
| {{Type|Optional}} {{Type|Position}}
 +
| The location that the player died at.
 +
|-
 +
| Portal cooldown
 +
| {{Type|VarInt}}
 +
| The number of ticks until the player can use the portal again.
 +
|-
 +
| Data kept
 +
| {{Type|Byte}}
 +
| Bit mask. 0x01: Keep attributes, 0x02: Keep metadata. Tells which data should be kept on the client side once the player has respawned.
 +
In the Notchian implementation, this is context dependent:
 +
* normal respawns (after death) keep no data;
 +
* exiting the end poem/credits keeps the attributes;
 +
* other dimension changes (portals or teleports) keep all data.
 +
|}
 +
 
 +
{{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).
  
=== Entity Head Look (0x23) ===
+
Before 1.16, 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.}}
 +
 
 +
==== Set Head Rotation ====
  
 
Changes the direction an entity's head is facing.
 
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.
 +
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="2"| 0x46
 +
| rowspan="2"| Play
 +
| rowspan="2"| Client
 +
| Entity ID
 +
| {{Type|VarInt}}
 +
|
 +
|-
 +
| Head Yaw
 +
| {{Type|Angle}}
 +
| New angle, not a delta.
 +
|}
 +
 +
==== Update Section Blocks ====
 +
 +
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 Update|Block Update]]).}}
 +
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="3"| 0x47
 +
| rowspan="3"| Play
 +
| rowspan="3"| Client
 +
| Chunk section position
 +
| {{Type|Long}}
 +
| Chunk section coordinate (encoded chunk x and z with each 22 bits, and section y with 20 bits, from left to right).
 +
|-
 +
| Blocks array size
 +
| {{Type|VarInt}}
 +
| Number of elements in the following array.
 +
|-
 +
| Blocks
 +
| {{Type|Array}} of {{Type|VarLong}}
 +
| Each entry is composed of the block state id, shifted left by 12, and the relative block position in the chunk section (4 bits for x, z, and y, from left to right).
 +
|}
 +
 +
Chunk section position is encoded:
 +
<syntaxhighlight lang="java">
 +
((sectionX & 0x3FFFFF) << 42) | (sectionY & 0xFFFFF) | ((sectionZ & 0x3FFFFF) << 20);
 +
</syntaxhighlight>
 +
and decoded:
 +
<syntaxhighlight lang="java">
 +
sectionX = long >> 42;
 +
sectionY = long << 44 >> 44;
 +
sectionZ = long << 22 >> 42;
 +
</syntaxhighlight>
 +
 +
Blocks are encoded:
 +
<syntaxhighlight lang="java">
 +
blockStateId << 12 | (blockLocalX << 8 | blockLocalZ << 4 | blockLocalY)
 +
//Uses the local position of the given block position relative to its respective chunk section
 +
</syntaxhighlight>
 +
and decoded:
 +
<syntaxhighlight lang="java">
 +
blockStateId = long >> 12;
 +
blockLocalX = (long >> 8) & 0xF;
 +
blockLocalY = long & 0xF;
 +
blockLocalZ = (long >> 4) & 0xF;
 +
</syntaxhighlight>
 +
 +
==== Select Advancements 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.
 +
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="2"| 0x48
 +
| rowspan="2"| Play
 +
| rowspan="2"| Client
 +
| Has id
 +
| {{Type|Boolean}}
 +
| Indicates if the next field is present.
 +
|-
 +
| Identifier
 +
| {{Type|Optional}} {{Type|Identifier}}
 +
| See below.
 +
|}
 +
 +
The {{Type|Identifier}} can be one of the following:
 +
 +
{| class="wikitable"
 +
! 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.
 +
 +
==== Server Data ====
 +
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="5"| 0x49
 +
| rowspan="5"| Play
 +
| rowspan="5"| Client
 +
| MOTD
 +
| {{Type|Text Component}}
 +
|
 +
|-
 +
| Has Icon
 +
| {{Type|Boolean}}
 +
|
 +
|-
 +
| Size
 +
| {{Type|VarInt}}
 +
| Number of bytes in the following array.
 +
|-
 +
| Icon
 +
| {{Type|Optional}} {{Type|Byte Array}}
 +
| Icon bytes in the PNG format
 +
|-
 +
| Enforces Secure Chat
 +
| {{Type|Boolean}}
 +
|
 +
|}
 +
 +
==== Set Action Bar Text ====
 +
 +
Displays a message above the hotbar. Equivalent to [[#System Chat Message|System Chat Message]] with Overlay set to true, except that [[Chat#Social Interactions (blocking)|chat message blocking]] isn't performed. Used by the Notchian server only to implement the <code>/title</code> command.
  
 
{| 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" | 0x23
+
| rowspan="1"| 0x4A
| class="col1 centeralign" | Entity ID
+
| rowspan="1"| Play
| class="col2 centeralign" | int
+
| rowspan="1"| Client
| class="col3 centeralign" |
+
| Action bar text
| class="col4" |
+
| {{Type|Text Component}}
|- class="row2"
+
|}
| class="col0 centeralign" | Head Yaw
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" |
 
| class="col3" | Head yaw in steps of 2π/256
 
|- class="row3"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 6 bytes
 
|}
 
  
=== Entity Status (0x26) ===
+
==== Set Border Center ====
  
'''Server to Client only'''
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="2"| 0x4B
 +
| rowspan="2"| Play
 +
| rowspan="2"| Client
 +
| X
 +
| {{Type|Double}}
 +
|
 +
|-
 +
| Z
 +
| {{Type|Double}}
 +
|
 +
|}
 +
 
 +
==== Set Border Lerp Size ====
  
 
{| 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="3"| 0x4C
| class="col1 centeralign" | Entity ID
+
| rowspan="3"| Play
| class="col2 centeralign" | Int
+
| rowspan="3"| Client
| class="col3 centeralign" | 34353
+
| Old Diameter
| class="col4" |  
+
| {{Type|Double}}
|- class="row3"
+
| Current length of a single side of the world border, in meters.
| class="col1 centeralign" | Entity Status
+
|-
| class="col2 centeralign" | Byte
+
| New Diameter
| class="col3 centeralign" | 0x03
+
| {{Type|Double}}
| class="col4" | See below
+
| Target length of a single side of the world border, in meters.
|- class="row4"
+
|-
! class="col0" | Total Size:
+
| Speed
| class="col1 rightalign" colspan="4" | 6 bytes
+
| {{Type|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.
 +
|}
 +
 
 +
==== Set Border Size ====
  
 
{| class="wikitable"
 
{| class="wikitable"
|-
+
! Packet ID
! Entity Status
+
! State
! Meaning
+
! Bound To
|-
+
! Field Name
| 2
+
! Field Type
| Entity hurt
+
! Notes
|-
+
|-
| 3
+
| rowspan="1"| 0x4D
| Entity dead
+
| rowspan="1"| Play
|-
+
| rowspan="1"| Client
| 6
+
| Diameter
| Wolf taming
+
| {{Type|Double}}
|-
+
| Length of a single side of the world border, in meters.
| 7
+
|}
| Wolf tamed
 
|-
 
| 8
 
| Wolf shaking water off itself
 
|-
 
| 9
 
| (of self) Eating accepted by server
 
|}
 
  
=== Attach Entity (0x27) ===
+
==== Set Border Warning Delay ====
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="1"| 0x4E
 +
| rowspan="1"| Play
 +
| rowspan="1"| Client
 +
| Warning Time
 +
| {{Type|VarInt}}
 +
| In seconds as set by <code>/worldborder warning time</code>.
 +
|}
  
(This packet data values are not fully verified)
+
==== Set Border Warning Distance ====
  
 
{| 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="1"| 0x4F
| class="col1 centeralign" | Entity ID
+
| rowspan="1"| Play
| class="col2 centeralign" | int
+
| rowspan="1"| Client
| class="col3 centeralign" | <code>1298</code>
+
| Warning Blocks
| class="col4" |
+
| {{Type|VarInt}}
The player entity ID being attached
+
| In meters.
|- class="row2"
+
|}
| class="col0 centeralign" | Vehicle ID
+
 
| class="col1 centeralign" | int
+
==== Set Camera ====
| class="col2 centeralign" | <code>1805</code>
+
 
| class="col3" |
+
Sets the entity that the player renders from. This is normally used when the player left-clicks an entity while in spectator mode.
The vehicle entity ID attached to (-1 for unattaching)
+
 
|- class="row3"
+
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).
! class="col0" | Total Size:
+
 
| class="col1 rightalign" colspan="4" | 9 bytes
+
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).
  
=== 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
+
| 0x50
| class="col1 centeralign" | Entity ID
+
| Play
| class="col2 centeralign" | int
+
| Client
| class="col3 centeralign" | <code>0x00000326</code>
+
| Camera ID
| class="col4 centeralign" | Unique entity ID to update.
+
| {{Type|VarInt}}
|- class="row2"
+
| ID of the entity to set the client's camera to.
| class="col0 centeralign" | Entity Metadata
+
|}
| class="col1 centeralign" | Metadata
+
 
| class="col2 centeralign" | <code>0x00 0x01 0x7F</code>
+
The notchian client also loads certain shaders for given entities:
| class="col3 centeralign" | Metadata varies by entity. See [[Entities]]
 
|- class="row3"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 5 bytes + Metadata
 
|}
 
  
=== Entity Effect (0x29) ===
+
* 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
 +
 
 +
==== Set Held Item (clientbound) ====
 +
 
 +
Sent to change the player's slot selection.
  
 
{| 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" | 0x29
+
| 0x51
| class="col1 centeralign" | Entity ID
+
| Play
| class="col2 centeralign" | int
+
| Client
| class="col3 centeralign" | <code>14</code>
+
| Slot
| class="col4" | Entity ID of a player
+
| {{Type|Byte}}
|- class="row2"
+
| The slot which the player has selected (0–8).
| class="col0 centeralign" | Effect ID
+
|}
| class="col1 centeralign" | byte
+
 
| class="col2 centeralign" | <code>17</code>
+
==== Set Center Chunk ====
| class="col3" | See table below
+
 
|- class="row3"
+
Sets the center position of the client's chunk loading area. The area is square-shaped, spanning 2 &times; server view distance + 7 chunks on both axes (width, not radius!). Since the area's width is always an odd number, there is no ambiguity as to which chunk is the center.
| class="col0 centeralign" | Amplifier
+
 
| class="col1 centeralign" | byte
+
The Notchian client ignores attempts to send chunks located outside the loading area, and immediately unloads any existing chunks no longer inside it.
| class="col2 centeralign" | <code>0</code>
 
| class="col3" |
 
|- class="row4"
 
| class="col0 centeralign" | Duration
 
| class="col1 centeralign" | short
 
| class="col2 centeralign" | <code>64</code>
 
| class="col3" |
 
|- class="row5"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 9 bytes
 
|}
 
  
==== Effects ====
+
The center chunk is normally the chunk the player is in, but apart from the implications on chunk loading, the (Notchian) client takes no issue with this not being the case. Indeed, as long as chunks are sent only within the default loading area centered on the world origin, it is not necessary to send this packet at all. This may be useful for servers with small bounded worlds, such as minigames, since it ensures chunks never need to be resent after the client has joined, saving on bandwidth.
 +
 
 +
The Notchian server sends this packet 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"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | ID
+
! State
! class="col1" | Meaning
+
! Bound To
! class="col2" | Client implementation
+
! Field Name
! class="col3" | Server implementation
+
! Field Type
|- class="row1"
+
! Notes
| class="col0" | 1
+
|-
| class="col1" | moveSpeed
+
| rowspan="2"| 0x52
| class="col2" | Increases player speed and FOV.
+
| rowspan="2"| Play
| class="col3" |
+
| rowspan="2"| Client
|- class="row1"
+
| Chunk X
| class="col0" | 2
+
| {{Type|VarInt}}
| class="col1" | moveSlowdown
+
| Chunk X coordinate of the loading area center.
| class="col2" | Decreases player speed and FOV.
+
|-
| class="col3" |
+
| Chunk Z
|- class="row1"
+
| {{Type|VarInt}}
| class="col0" | 3
+
| Chunk Z coordinate of the loading area center.
| class="col1" | digSpeed
+
|}
| class="col2" | Increases player dig speed
 
| class="col3" |
 
|- class="row1"
 
| class="col0" | 4
 
| class="col1" | digSlowDown
 
| class="col2" | Decreases player dig speed
 
| class="col3" |
 
|- class="row1"
 
| class="col0" | 5
 
| class="col1" | damageBoost
 
| class="col2" |
 
| class="col3" |
 
|- class="row1"
 
| class="col0" | 6
 
| class="col1" | heal
 
| class="col2" |
 
| class="col3" |
 
|- class="row1"
 
| class="col0" | 7
 
| class="col1" | harm
 
| class="col2" |
 
| class="col3" |
 
|- class="row1"
 
| class="col0" | 8
 
| class="col1" | jump
 
| class="col2" |
 
| class="col3" |
 
|- class="row1"
 
| class="col0" | 9
 
| class="col1" | confusion
 
| class="col2" | Portal-like effect
 
| class="col3" |
 
|- class="row1"
 
| class="col0" | 10
 
| class="col1" | regeneration
 
| class="col2" | Hearts pulse one-by-one
 
| class="col3" | Caused by golden apple. Health regenerates over 600-tick (30s) period.
 
|- class="row1"
 
| class="col0" | 11
 
| class="col1" | resistance
 
| class="col2" |
 
| class="col3" |
 
|- class="row1"
 
| class="col0" | 12
 
| class="col1" | fireResistance
 
| class="col2" |
 
| class="col3" |
 
|- class="row1"
 
| class="col0" | 13
 
| class="col1" | waterBreathing
 
| class="col2" | Bubbles do not decrease underwater
 
| class="col3" |
 
|- class="row1"
 
| class="col0" | 14
 
| class="col1" | invisibility
 
| class="col2" |
 
| class="col3" |
 
|- class="row1"
 
| class="col0" | 15
 
| class="col1" | blindness
 
| class="col2" |
 
| class="col3" |
 
|- class="row1"
 
| class="col0" | 16
 
| class="col1" | nightVision
 
| class="col2" |
 
| class="col3" |
 
|- class="row1"
 
| class="col0" | 17
 
| class="col1" | hunger
 
| class="col2" | Food bar turns green
 
| class="col3" | Caused by poisoning from Rotten Flesh or Raw Chicken
 
|- class="row1"
 
| class="col0" | 18
 
| class="col1" | weakness
 
| class="col2" |
 
| class="col3" |
 
|- class="row1"
 
| class="col0" | 19
 
| class="col1" | poison
 
| class="col2" | Hearts turn yellow
 
| class="col3" | Caused by poisoning from cave (blue) spider
 
|}
 
  
=== Remove Entity Effect (0x2A) ===
+
==== Set Render Distance ====
  
 +
Sent by the integrated singleplayer server when changing render distance.  This packet is sent by the server when the client reappears in the overworld after leaving the end.
  
 
{| 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" | 0x2a
+
| 0x53
| class="col1 centeralign" | Entity ID
+
| Play
| class="col2 centeralign" | int
+
| Client
| class="col3 centeralign" |
+
| View Distance
| class="col4" | Entity ID of a player
+
| {{Type|VarInt}}
|- class="row2"
+
| Render distance (2-32).
| class="col0 centeralign" | Effect ID
+
|}
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>17</code>
 
| class="col3" | See [[#Effects|table above]]
 
|- class="row3"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 6 bytes
 
|}
 
  
=== Experience (0x2B) ===
+
==== Set Default 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="2"| 0x54
 +
| rowspan="2"| Play
 +
| rowspan="2"| Client
 +
| Location
 +
| {{Type|Position}}
 +
| Spawn location.
 +
|-
 +
| Angle
 +
| {{Type|Float}}
 +
| The angle at which to respawn at.
 +
|}
 +
 
 +
==== Display Objective ====
 +
 
 +
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"| 0x55
 +
| rowspan="2"| Play
 +
| rowspan="2"| Client
 +
| Position
 +
| {{Type|VarInt}}
 +
| The position of the scoreboard. 0: list, 1: sidebar, 2: below name, 3 - 18: team specific sidebar, indexed as 3 + team color.
 +
|-
 +
| Score Name
 +
| {{Type|String}} (32767)
 +
| The unique name for the scoreboard to be displayed.
 +
|}
 +
 
 +
==== Set Entity Metadata ====
 +
 
 +
Updates one or more [[Entity_metadata#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"| 0x56
 +
| rowspan="2"| Play
 +
| rowspan="2"| Client
 +
| Entity ID
 +
| {{Type|VarInt}}
 +
|
 +
|-
 +
| Metadata
 +
| [[Entity_metadata#Entity Metadata Format|Entity Metadata]]
 +
|
 +
|}
 +
 
 +
==== Link Entities ====
 +
 
 +
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"| 0x57
 +
| rowspan="2"| Play
 +
| rowspan="2"| Client
 +
| Attached Entity ID
 +
| {{Type|Int}}
 +
| Attached entity's EID.
 +
|-
 +
| Holding Entity ID
 +
| {{Type|Int}}
 +
| ID of the entity holding the lead. Set to -1 to detach.
 +
|}
 +
 
 +
==== Set Entity Velocity ====
 +
 
 +
Velocity is 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"| 0x58
 +
| rowspan="4"| Play
 +
| rowspan="4"| Client
 +
| Entity ID
 +
| {{Type|VarInt}}
 +
|
 +
|-
 +
| Velocity X
 +
| {{Type|Short}}
 +
| Velocity on the X axis.
 +
|-
 +
| Velocity Y
 +
| {{Type|Short}}
 +
| Velocity on the Y axis.
 +
|-
 +
| Velocity Z
 +
| {{Type|Short}}
 +
| Velocity on the Z axis.
 +
|}
 +
 
 +
==== Set Equipment ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! colspan="2"| Field Name
 +
! colspan="2"| Field Type
 +
! Notes
 +
|-
 +
| rowspan="3"| 0x59
 +
| rowspan="3"| Play
 +
| rowspan="3"| Client
 +
| colspan="2"| Entity ID
 +
| colspan="2"| {{Type|VarInt}}
 +
| Entity's ID.
 +
|-
 +
| rowspan="2"| Equipment
 +
| Slot
 +
| rowspan="2"| {{Type|Array}}
 +
| {{Type|Byte}} {{Type|Enum}}
 +
| Equipment slot. 0: main hand, 1: off hand, 2–5: armor slot (2: boots, 3: leggings, 4: chestplate, 5: helmet).  Also has the top bit set if another entry follows, and otherwise unset if this is the last item in the array.
 +
|-
 +
| Item
 +
| {{Type|Slot}}
 +
|
 +
|}
 +
 
 +
==== Set Experience ====
  
 
Sent by the server when the client should change experience levels.
 
Sent by the server when the client should change experience levels.
  
 
{| 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" | 0x2B
+
| rowspan="3"| 0x5A
| class="col1 centeralign" | Experience bar
+
| rowspan="3"| Play
| class="col2 centeralign" | float
+
| rowspan="3"| Client
| class="col3 centeralign" | <code>0.5960060358047485</code>
+
| Experience bar
| class="col4" | Used for drawing the experience bar - value is between 0 and 1.
+
| {{Type|Float}}
|- class="row2"
+
| Between 0 and 1.
| class="col0 centeralign" | Level
+
|-
| class="col1 centeralign" | short
+
| Level
| class="col2 centeralign" | <code>8</code>
+
| {{Type|VarInt}}
| class="col4" |
+
|
|- class="row3"
+
|-
| class="col0 centeralign" | Total experience
+
| Total Experience
| class="col1 centeralign" | short
+
| {{Type|VarInt}}
| class="col2 centeralign" | <code>130</code>
+
| See {{Minecraft Wiki|Experience#Leveling up}} on the Minecraft Wiki for Total Experience to Level conversion.
| class="col3" |
+
|}
|- class="row4"
+
 
! class="col0" | Total Size:
+
==== Set Health ====
| class="col1 rightalign" colspan="4" | 9 bytes
+
 
|}
+
Sent by the server to set the health of the player it is sent to.
 +
 
 +
Food {{Minecraft Wiki|Food#Hunger and saturation|saturation}} acts as a food “overcharge”. Food values will not decrease while the saturation is over zero. New players logging in or respawning 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"| 0x5B
 +
| rowspan="3"| Play
 +
| rowspan="3"| Client
 +
| Health
 +
| {{Type|Float}}
 +
| 0 or less = dead, 20 = full HP.
 +
|-
 +
| Food
 +
| {{Type|VarInt}}
 +
| 0–20.
 +
|-
 +
| Food Saturation
 +
| {{Type|Float}}
 +
| Seems to vary from 0.0 to 5.0 in integer increments.
 +
|}
 +
 
 +
==== Update Objectives ====
 +
 
 +
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
 +
! colspan="2"| Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="10"| 0x5C
 +
| rowspan="10"| Play
 +
| rowspan="10"| Client
 +
| colspan="2"| Objective Name
 +
| {{Type|String}} (32767)
 +
| A unique name for the objective.
 +
|-
 +
| colspan="2"| Mode
 +
| {{Type|Byte}}
 +
| 0 to create the scoreboard. 1 to remove the scoreboard. 2 to update the display text.
 +
|-
 +
| colspan="2"| Objective Value
 +
| {{Type|Optional}} {{Type|Text Component}}
 +
| Only if mode is 0 or 2.The text to be displayed for the score.
 +
|-
 +
| colspan="2"| Type
 +
| {{Type|Optional}} {{Type|VarInt}} {{Type|Enum}}
 +
| Only if mode is 0 or 2. 0 = "integer", 1 = "hearts".
 +
|-
 +
| colspan="2"| Has Number Format
 +
| {{Type|Optional}} {{Type|Boolean}}
 +
| Only if mode is 0 or 2. Whether this objective has a set number format for the scores.
 +
|-
 +
| colspan="2"| Number Format
 +
| {{Type|Optional}} {{Type|VarInt}} {{Type|Enum}}
 +
| Only if mode is 0 or 2 and the previous boolean is true. Determines how the score number should be formatted.
 +
|-
 +
! Number Format
 +
! Field Name
 +
!
 +
!
 +
|-
 +
| 0: blank
 +
| colspan="2"| ''no fields''
 +
| Show nothing.
 +
|-
 +
| 1: styled
 +
| Styling
 +
| [[NBT#Specification:compound_tag|Compound Tag]]
 +
| The styling to be used when formatting the score number. Contains the [[Text formatting#Styling fields|text component styling fields]].
 +
|-
 +
| 2: fixed
 +
| Content
 +
| {{Type|Text Component}}
 +
| The text to be used as placeholder.
 +
|}
 +
 
 +
==== Set Passengers ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="3"| 0x5D
 +
| rowspan="3"| Play
 +
| rowspan="3"| Client
 +
| Entity ID
 +
| {{Type|VarInt}}
 +
| Vehicle's EID.
 +
|-
 +
| Passenger Count
 +
| {{Type|VarInt}}
 +
| Number of elements in the following array.
 +
|-
 +
| Passengers
 +
| {{Type|Array}} of {{Type|VarInt}}
 +
| EIDs of entity's passengers.
 +
|}
 +
 
 +
==== Update Teams ====
 +
 
 +
Creates and updates teams.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! colspan="2"| Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="23"| 0x5E
 +
| rowspan="23"| Play
 +
| rowspan="23"| Client
 +
| colspan="2"| Team Name
 +
| {{Type|String}} (32767)
 +
| A unique name for the team. (Shared with scoreboard).
 +
|-
 +
| colspan="2"| Mode
 +
| {{Type|Byte}}
 +
| Determines the layout of the remaining packet.
 +
|-
 +
| rowspan="9"| 0: create team
 +
| Team Display Name
 +
| {{Type|Text Component}}
 +
|
 +
|-
 +
| Friendly Flags
 +
| {{Type|Byte}}
 +
| Bit mask. 0x01: Allow friendly fire, 0x02: can see invisible players on same team.
 +
|-
 +
| Name Tag Visibility
 +
| {{Type|String}} {{Type|Enum}} (40)
 +
| <code>always</code>, <code>hideForOtherTeams</code>, <code>hideForOwnTeam</code>, <code>never</code>.
 +
|-
 +
| Collision Rule
 +
| {{Type|String}} {{Type|Enum}} (40)
 +
| <code>always</code>, <code>pushOtherTeams</code>, <code>pushOwnTeam</code>, <code>never</code>.
 +
|-
 +
| Team Color
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| Used to color the name of players on the team; see below.
 +
|-
 +
| Team Prefix
 +
| {{Type|Text Component}}
 +
| Displayed before the names of players that are part of this team.
 +
|-
 +
| Team Suffix
 +
| {{Type|Text Component}}
 +
| Displayed after the names of players that are part of this team.
 +
|-
 +
| Entity Count
 +
| {{Type|VarInt}}
 +
| Number of elements in the following array.
 +
|-
 +
| Entities
 +
| {{Type|Array}} of {{Type|String}} (32767)
 +
| 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
 +
| {{Type|Text Component}}
 +
|
 +
|-
 +
| Friendly Flags
 +
| {{Type|Byte}}
 +
| Bit mask. 0x01: Allow friendly fire, 0x02: can see invisible entities on same team.
 +
|-
 +
| Name Tag Visibility
 +
| {{Type|String}} {{Type|Enum}} (40)
 +
| <code>always</code>, <code>hideForOtherTeams</code>, <code>hideForOwnTeam</code>, <code>never</code>
 +
|-
 +
| Collision Rule
 +
| {{Type|String}} {{Type|Enum}} (40)
 +
| <code>always</code>, <code>pushOtherTeams</code>, <code>pushOwnTeam</code>, <code>never</code>
 +
|-
 +
| Team Color
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| Used to color the name of players on the team; see below.
 +
|-
 +
| Team Prefix
 +
| {{Type|Text Component}}
 +
| Displayed before the names of players that are part of this team.
 +
|-
 +
| Team Suffix
 +
| {{Type|Text Component}}
 +
| Displayed after the names of players that are part of this team.
 +
|-
 +
| rowspan="2"| 3: add entities to team
 +
| Entity Count
 +
| {{Type|VarInt}}
 +
| Number of elements in the following array.
 +
|-
 +
| Entities
 +
| {{Type|Array}} of {{Type|String}} (32767)
 +
| Identifiers for the added entities.  For players, this is their username; for other entities, it is their UUID.
 +
|-
 +
| rowspan="2"| 4: remove entities from team
 +
| Entity Count
 +
| {{Type|VarInt}}
 +
| Number of elements in the following array.
 +
|-
 +
| Entities
 +
| {{Type|Array}} of {{Type|String}} (32767)
 +
| Identifiers for the removed entities.  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 in [[Text formatting#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
 +
! colspan="2"| Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="11"| 0x5F
 +
| rowspan="11"| Play
 +
| rowspan="11"| Client
 +
| colspan="2"| Entity Name
 +
| {{Type|String}} (32767)
 +
| The entity whose score this is. For players, this is their username; for other entities, it is their UUID.
 +
|-
 +
| colspan="2"| Objective Name
 +
| {{Type|String}} (32767)
 +
| The name of the objective the score belongs to.
 +
|-
 +
| colspan="2"| Value
 +
| {{Type|VarInt}}
 +
| The score to be displayed next to the entry.
 +
|-
 +
| colspan="2"| Has Display Name
 +
| {{Type|Boolean}}
 +
| Whether this score has a custom display name.
 +
|-
 +
| colspan="2"| Display Name
 +
| {{Type|Optional}} {{Type|Text Component}}
 +
| The custom display name. Only present if the previous boolean is true.
 +
|-
 +
| colspan="2"| Has Number Format
 +
| {{Type|Boolean}}
 +
| Whether this score has a set number format. This overrides the number format set on the objective, if any.
 +
|-
 +
| colspan="2"| Number Format
 +
| {{Type|Optional}} {{Type|VarInt}} {{Type|Enum}}
 +
| Determines how the score number should be formatted. Only present if the previous boolean is true.
 +
|-
 +
! Number Format
 +
! Field Name
 +
!
 +
!
 +
|-
 +
| 0: blank
 +
| colspan="2"| ''no fields''
 +
| Show nothing.
 +
|-
 +
| 1: styled
 +
| Styling
 +
| [[NBT#Specification:compound_tag|Compound Tag]]
 +
| The styling to be used when formatting the score number. Contains the [[Text formatting#Styling fields|text component styling fields]].
 +
|-
 +
| 2: fixed
 +
| Content
 +
| {{Type|Text Component}}
 +
| The text to be used as placeholder.
 +
|}
 +
 
 +
==== Set Simulation Distance ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x60
 +
| Play
 +
| Client
 +
| Simulation Distance
 +
| {{Type|VarInt}}
 +
| The distance that the client will process specific things, such as entities.
 +
|}
 +
 
 +
==== Set Subtitle Text ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="1"| 0x61
 +
| rowspan="1"| Play
 +
| rowspan="1"| Client
 +
| Subtitle Text
 +
| {{Type|Text Component}}
 +
|
 +
|}
 +
 
 +
==== Update Time ====
 +
 
 +
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"| 0x62
 +
| rowspan="2"| Play
 +
| rowspan="2"| Client
 +
| World Age
 +
| {{Type|Long}}
 +
| In ticks; not changed by server commands.
 +
|-
 +
| Time of day
 +
| {{Type|Long}}
 +
| The world (or region) time, in ticks. If negative the sun will stop moving at the Math.abs of the time.
 +
|}
 +
 
 +
==== Set Title Text ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="1"| 0x63
 +
| rowspan="1"| Play
 +
| rowspan="1"| Client
 +
| Title Text
 +
| {{Type|Text Component}}
 +
|
 +
|}
 +
 
 +
==== Set Title Animation Times ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="3"| 0x64
 +
| rowspan="3"| Play
 +
| rowspan="3"| Client
 +
| Fade In
 +
| {{Type|Int}}
 +
| Ticks to spend fading in.
 +
|-
 +
| Stay
 +
| {{Type|Int}}
 +
| Ticks to keep the title displayed.
 +
|-
 +
| Fade Out
 +
| {{Type|Int}}
 +
| Ticks to spend fading out, not when to start fading out.
 +
|}
 +
 
 +
==== Entity Sound Effect ====
 +
 
 +
Plays a sound effect from an entity, either by hardcoded ID or Identifier. Sound IDs and names can be found [https://pokechu22.github.io/Burger/1.20.4.html#sounds here].
 +
 
 +
{{Warning|Numeric sound effect IDs are liable to change between versions}}
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="9"| 0x65
 +
| rowspan="9"| Play
 +
| rowspan="9"| Client
 +
| Sound ID
 +
| {{Type|VarInt}}
 +
| Represents the <code>Sound ID + 1</code>. If the value is 0, the packet contains a sound specified by Identifier.
 +
|-
 +
| Sound Name
 +
| {{Type|Optional}} {{Type|Identifier}}
 +
| Only present if Sound ID is 0
 +
|-
 +
| Has Fixed Range
 +
| {{Type|Optional}} {{Type|Boolean}}
 +
| Only present if Sound ID is 0.
 +
|-
 +
| Range
 +
| {{Type|Optional}} {{Type|Float}}
 +
| The fixed range of the sound. Only present if previous boolean is true and Sound ID is 0.
 +
|-
 +
| Sound Category
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| The category that this sound will be played from ([https://gist.github.com/konwboj/7c0c380d3923443e9d55 current categories]).
 +
|-
 +
| Entity ID
 +
| {{Type|VarInt}}
 +
|
 +
|-
 +
| Volume
 +
| {{Type|Float}}
 +
| 1.0 is 100%, capped between 0.0 and 1.0 by Notchian clients.
 +
|-
 +
| Pitch
 +
| {{Type|Float}}
 +
| Float between 0.5 and 2.0 by Notchian clients.
 +
|-
 +
| Seed
 +
| {{Type|Long}}
 +
| Seed used to pick sound variant.
 +
|}
 +
 
 +
==== Sound Effect ====
 +
 
 +
Plays a sound effect at the given location, either by hardcoded ID or Identifier. Sound IDs and names can be found [https://pokechu22.github.io/Burger/1.20.4.html#sounds here].
 +
 
 +
{{Warning|Numeric sound effect IDs are liable to change between versions}}
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="11"| 0x66
 +
| rowspan="11"| Play
 +
| rowspan="11"| Client
 +
| Sound ID
 +
| {{Type|VarInt}}
 +
| Represents the <code>Sound ID + 1</code>. If the value is 0, the packet contains a sound specified by Identifier.
 +
|-
 +
| Sound Name
 +
| {{Type|Optional}} {{Type|Identifier}}
 +
| Only present if Sound ID is 0
 +
|-
 +
| Has Fixed Range
 +
| {{Type|Optional}} {{Type|Boolean}}
 +
| Only present if Sound ID is 0.
 +
|-
 +
| Range
 +
| {{Type|Optional}} {{Type|Float}}
 +
| The fixed range of the sound. Only present if previous boolean is true and Sound ID is 0.
 +
|-
 +
| Sound Category
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| The category that this sound will be played from ([https://gist.github.com/konwboj/7c0c380d3923443e9d55 current categories]).
 +
|-
 +
| Effect Position X
 +
| {{Type|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
 +
| {{Type|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
 +
| {{Type|Int}}
 +
| Effect Z multiplied by 8 ([[Data types#Fixed-point numbers|fixed-point number]] with only 3 bits dedicated to the fractional part).
 +
|-
 +
| Volume
 +
| {{Type|Float}}
 +
| 1.0 is 100%, capped between 0.0 and 1.0 by Notchian clients.
 +
|-
 +
| Pitch
 +
| {{Type|Float}}
 +
| Float between 0.5 and 2.0 by Notchian clients.
 +
|-
 +
| Seed
 +
| {{Type|Long}}
 +
| Seed used to pick sound variant.
 +
|}
 +
 
 +
==== Start Configuration ====
 +
 
 +
Sent during gameplay in order to redo the configuration process. The client must respond with [[#Acknowledge Configuration|Acknowledge Configuration]] for the process to start.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="1"| 0x67
 +
| rowspan="1"| Play
 +
| rowspan="1"| Client
 +
| colspan="3"| ''no fields''
 +
|}
 +
 
 +
This packet switches the connection state to [[#Configuration|configuration]].
 +
 
 +
==== Stop Sound ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="3"| 0x68
 +
| rowspan="3"| Play
 +
| rowspan="3"| Client
 +
| Flags
 +
| {{Type|Byte}}
 +
| Controls which fields are present.
 +
|-
 +
| Source
 +
| {{Type|Optional}} {{Type|VarInt}} {{Type|Enum}}
 +
| Only if flags is 3 or 1 (bit mask 0x1). See below. If not present, then sounds from all sources are cleared.
 +
|-
 +
| Sound
 +
| {{Type|Optional}} {{Type|Identifier}}
 +
| Only if flags is 2 or 3 (bit mask 0x2).  A sound effect name, see [[#Custom Sound Effect|Custom 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
 +
|}
 +
 
 +
==== System Chat Message ====
 +
 
 +
Sends the client a raw system message.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="2"| 0x69
 +
| rowspan="2"| Play
 +
| rowspan="2"| Client
 +
| Content
 +
| {{Type|Text Component}}
 +
| Limited to 262144 bytes.
 +
|-
 +
| Overlay
 +
| {{Type|Boolean}}
 +
| Whether the message is an actionbar or chat message. See also [[#Set Action Bar Text]].
 +
|}
 +
 
 +
==== Set Tab 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"| 0x6A
 +
| rowspan="2"| Play
 +
| rowspan="2"| Client
 +
| Header
 +
| {{Type|Text Component}}
 +
| To remove the header, send a empty text component: <code>{"text":""}</code>.
 +
|-
 +
| Footer
 +
| {{Type|Text Component}}
 +
| To remove the footer, send a empty text component: <code>{"text":""}</code>.
 +
|}
 +
 
 +
==== Tag Query Response ====
 +
 
 +
Sent in response to [[#Query Block Entity Tag|Query Block Entity Tag]] or [[#Query Entity Tag|Query Entity Tag]].
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="2"| 0x6B
 +
| rowspan="2"| Play
 +
| rowspan="2"| Client
 +
| Transaction ID
 +
| {{Type|VarInt}}
 +
| Can be compared to the one sent in the original query packet.
 +
|-
 +
| NBT
 +
| {{Type|NBT}}
 +
| The NBT of the block or entity.  May be a TAG_END (0) in which case no NBT is present.
 +
|}
 +
 
 +
==== Pickup 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 [[#Set Player Position|Set Player Position]] (and [[#Set Player Position And Rotation|Set Player Position And Rotation]]) 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"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="3"| 0x6C
 +
| rowspan="3"| Play
 +
| rowspan="3"| Client
 +
| Collected Entity ID
 +
| {{Type|VarInt}}
 +
|
 +
|-
 +
| Collector Entity ID
 +
| {{Type|VarInt}}
 +
|
 +
|-
 +
| Pickup Item Count
 +
| {{Type|VarInt}}
 +
| Seems to be 1 for XP orbs, otherwise the number of items in the stack.
 +
|}
 +
 
 +
==== Teleport Entity ====
 +
 
 +
This packet is sent by the server when an entity moves more than 8 blocks.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="7"| 0x6D
 +
| rowspan="7"| Play
 +
| rowspan="7"| Client
 +
| Entity ID
 +
| {{Type|VarInt}}
 +
|
 +
|-
 +
| X
 +
| {{Type|Double}}
 +
|
 +
|-
 +
| Y
 +
| {{Type|Double}}
 +
|
 +
|-
 +
| Z
 +
| {{Type|Double}}
 +
|
 +
|-
 +
| Yaw
 +
| {{Type|Angle}}
 +
| (Y Rot)New angle, not a delta.
 +
|-
 +
| Pitch
 +
| {{Type|Angle}}
 +
| (X Rot)New angle, not a delta.
 +
|-
 +
| On Ground
 +
| {{Type|Boolean}}
 +
|
 +
|}
 +
 
 +
==== Set Ticking State ====
 +
 
 +
Used to adjust the ticking rate of the client, and whether it's frozen.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="2" | 0x6E
 +
| rowspan="2" | Play
 +
| rowspan="2" | Client
 +
| Tick rate
 +
| {{Type|Float}}
 +
|
 +
|-
 +
| Is frozen
 +
| {{Type|Boolean}}
 +
|
 +
|}
 +
 
 +
==== Step Tick ====
 +
 
 +
Advances the client processing by the specified number of ticks. Has no effect unless client ticking is frozen.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x6F
 +
| Play
 +
| Client
 +
| Tick steps
 +
| {{Type|VarInt}}
 +
|
 +
|}
 +
 
 +
==== Update Advancements ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! colspan="2"| Field Name
 +
! colspan="2"| Field Type
 +
! Notes
 +
|-
 +
| rowspan="9"| 0x70
 +
| rowspan="9"| Play
 +
| rowspan="9"| Client
 +
| colspan="2"| Reset/Clear
 +
| colspan="2"| {{Type|Boolean}}
 +
| Whether to reset/clear the current advancements.
 +
|-
 +
| colspan="2"| Mapping size
 +
| colspan="2"| {{Type|VarInt}}
 +
| Size of the following array.
 +
|-
 +
| rowspan="2"| Advancement mapping
 +
| Key
 +
| rowspan="2"| {{Type|Array}}
 +
| {{Type|Identifier}}
 +
| The identifier of the advancement.
 +
|-
 +
| Value
 +
| Advancement
 +
| See below
 +
|-
 +
| colspan="2"| List size
 +
| colspan="2"| {{Type|VarInt}}
 +
| Size of the following array.
 +
|-
 +
| colspan="2"| Identifiers
 +
| colspan="2"| {{Type|Array}} of {{Type|Identifier}}
 +
| The identifiers of the advancements that should be removed.
 +
|-
 +
| colspan="2"| Progress size
 +
| colspan="2"| {{Type|VarInt}}
 +
| Size of the following array.
 +
|-
 +
| rowspan="2"| Progress mapping
 +
| Key
 +
| rowspan="2"| {{Type|Array}}
 +
| {{Type|Identifier}}
 +
| The identifier of the advancement.
 +
|-
 +
| Value
 +
| Advancement progress
 +
| See below.
 +
|}
 +
 
 +
Advancement structure:
 +
 
 +
{| class="wikitable"
 +
! colspan="2"| Field Name
 +
! colspan="2"| Field Type
 +
! Notes
 +
|-
 +
| colspan="2"| Has parent
 +
| colspan="2"| {{Type|Boolean}}
 +
| Indicates whether the next field exists.
 +
|-
 +
| colspan="2"| Parent id
 +
| colspan="2"| {{Type|Optional}} {{Type|Identifier}}
 +
| The identifier of the parent advancement.
 +
|-
 +
| colspan="2"| Has display
 +
| colspan="2"| {{Type|Boolean}}
 +
| Indicates whether the next field exists.
 +
|-
 +
| colspan="2"| Display data
 +
| colspan="2"| {{Type|Optional}} Advancement display
 +
| See below.
 +
|-
 +
| colspan="2"| Array length
 +
| colspan="2"| {{Type|VarInt}}
 +
| Number of arrays in the following array.
 +
|-
 +
| rowspan="2"| Requirements
 +
| Array length 2
 +
| rowspan="2"| {{Type|Array}}
 +
| {{Type|VarInt}}
 +
| Number of elements in the following array.
 +
|-
 +
| Requirement
 +
| {{Type|Array}} of {{Type|String}} (32767)
 +
| Array of required criteria.
 +
|-
 +
| colspan="2"| Sends telemetry data
 +
| colspan="2"| {{Type|Boolean}}
 +
| Whether the client should include this achievement in the telemetry data when it's completed.
 +
The Notchian client only sends data for advancements on the <code>minecraft</code> namespace.
 +
|}
 +
 
 +
Advancement display:
 +
 
 +
{| class="wikitable"
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| Title
 +
| {{Type|Text Component}}
 +
|
 +
|-
 +
| Description
 +
| {{Type|Text Component}}
 +
|
 +
|-
 +
| Icon
 +
| {{Type|Slot}}
 +
|
 +
|-
 +
| Frame type
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| 0 = <code>task</code>, 1 = <code>challenge</code>, 2 = <code>goal</code>.
 +
|-
 +
| Flags
 +
| {{Type|Int}}
 +
| 0x01: has background texture; 0x02: <code>show_toast</code>; 0x04: <code>hidden</code>.
 +
|-
 +
| Background texture
 +
| {{Type|Optional}} {{Type|Identifier}}
 +
| Background texture location.  Only if flags indicates it.
 +
|-
 +
| X coord
 +
| {{Type|Float}}
 +
|
 +
|-
 +
| Y coord
 +
| {{Type|Float}}
 +
|
 +
|}
 +
 
 +
Advancement progress:
 +
 
 +
{| class="wikitable"
 +
! colspan="2"| Field Name
 +
! colspan="2"| Field Type
 +
! Notes
 +
|-
 +
| colspan="2"| Size
 +
| colspan="2"| {{Type|VarInt}}
 +
| Size of the following array.
 +
|-
 +
| rowspan="2"| Criteria
 +
| Criterion identifier
 +
| rowspan="2"| {{Type|Array}}
 +
| {{Type|Identifier}}
 +
| The identifier of the criterion.
 +
|-
 +
| Criterion progress
 +
| Criterion progress
 +
|
 +
|}
 +
 
 +
Criterion progress:
 +
 
 +
{| class="wikitable"
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| Achieved
 +
| {{Type|Boolean}}
 +
| If true, next field is present.
 +
|-
 +
| Date of achieving
 +
| {{Type|Optional}} {{Type|Long}}
 +
| As returned by [https://docs.oracle.com/javase/6/docs/api/java/util/Date.html#getTime() <code>Date.getTime</code>].
 +
|}
 +
 
 +
==== Update Attributes ====
 +
 
 +
Sets {{Minecraft Wiki|Attribute|attributes}} on the given entity.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! colspan="2"| Field Name
 +
! colspan="2"| Field Type
 +
! Notes
 +
|-
 +
| rowspan="6"| 0x71
 +
| rowspan="6"| Play
 +
| rowspan="6"| Client
 +
| colspan="2"| Entity ID
 +
| colspan="2"| {{Type|VarInt}}
 +
|
 +
|-
 +
| colspan="2"| Number Of Properties
 +
| colspan="2"| {{Type|VarInt}}
 +
| Number of elements in the following array.
 +
|-
 +
| rowspan="4"| Property
 +
| Key
 +
| rowspan="4"| {{Type|Array}}
 +
| {{Type|Identifier}}
 +
| See below.
 +
|-
 +
| Value
 +
| {{Type|Double}}
 +
| See below.
 +
|-
 +
| Number Of Modifiers
 +
| {{Type|VarInt}}
 +
| Number of elements in the following array.
 +
|-
 +
| Modifiers
 +
| {{Type|Array}} of Modifier Data
 +
| See {{Minecraft Wiki|Attribute#Modifiers}}. Modifier Data defined below.
 +
|}
 +
 
 +
Known Key values (see also {{Minecraft Wiki|Attribute#Modifiers}}):
 +
 
 +
{| class="wikitable"
 +
|-
 +
! Key
 +
! Default
 +
! Min
 +
! Max
 +
! Label
 +
|-
 +
| generic.max_health
 +
| 20.0
 +
| 1.0
 +
| 1024.0
 +
| Max Health.
 +
|-
 +
| generic.follow_range
 +
| 32.0
 +
| 0.0
 +
| 2048.0
 +
| Follow Range.
 +
|-
 +
| generic.knockback_resistance
 +
| 0.0
 +
| 0.0
 +
| 1.0
 +
| Knockback Resistance.
 +
|-
 +
| generic.movement_speed
 +
| 0.7
 +
| 0.0
 +
| 1024.0
 +
| Movement Speed.
 +
|-
 +
| generic.flying_speed
 +
| 0.4
 +
| 0.0
 +
| 1024.0
 +
| Flying Speed.
 +
|-
 +
| generic.attack_damage
 +
| 2.0
 +
| 0.0
 +
| 2048.0
 +
| Attack Damage.
 +
|-
 +
| generic.attack_knockback
 +
| 0.0
 +
| 0.0
 +
| 5.0
 +
| &mdash;
 +
|-
 +
| generic.attack_speed
 +
| 4.0
 +
| 0.0
 +
| 1024.0
 +
| Attack Speed.
 +
|-
 +
| generic.armor
 +
| 0.0
 +
| 0.0
 +
| 30.0
 +
| Armor.
 +
|-
 +
| generic.armor_toughness
 +
| 0.0
 +
| 0.0
 +
| 20.0
 +
| Armor Toughness.
 +
|-
 +
| generic.luck
 +
| 0.0
 +
| -1024.0
 +
| 1024.0
 +
| Luck.
 +
|-
 +
| zombie.spawn_reinforcements
 +
| 0.0
 +
| 0.0
 +
| 1.0
 +
| Spawn Reinforcements Chance.
 +
|-
 +
| horse.jump_strength
 +
| 0.7
 +
| 0.0
 +
| 2.0
 +
| Jump Strength.
 +
|-
 +
| 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).
 +
|}
  
=== Pre-Chunk (0x32) ===
+
''Modifier Data'' structure:
  
'''Server to Client only'''
+
{| class="wikitable"
 +
|-
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| UUID
 +
| {{Type|UUID}}
 +
|
 +
|-
 +
| Amount
 +
| {{Type|Double}}
 +
| May be positive or negative.
 +
|-
 +
| Operation
 +
| {{Type|Byte}}
 +
| See below.
 +
|}
  
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.
+
The operation controls how the base value of the modifier is changed.
  
[[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.
+
* 0: Add/subtract amount
 +
* 1: Add/subtract amount percent of the current value
 +
* 2: Multiply by amount percent
  
When sending initial terrain to spawn the player, make sure all pre-chunks are sent before all chunks.
+
All of the 0's are applied first, and then the 1's, and then the 2's.
 +
 
 +
==== 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="3" | 0x32
+
| rowspan="7"| 0x72
| class="col1 centeralign" | X
+
| rowspan="7"| Play
| class="col2 centeralign" | int
+
| rowspan="7"| Client
| class="col3 centeralign" | <code>-9</code>
+
| Entity ID
| class="col4" | Chunk X Coordinate
+
| {{Type|VarInt}}
|- class="row2"
+
|
| class="col0 centeralign" | Z
+
|-
| class="col1 centeralign" | int
+
| Effect ID
| class="col2 centeralign" | <code>12</code>
+
| {{Type|VarInt}}
| class="col3" | Chunk Z Coordinate
+
| See {{Minecraft Wiki|Status effect#Effect list|this table}}.
|- class="row3"
+
|-
| class="col0 centeralign" | Mode
+
| Amplifier
| class="col1 centeralign" | bool
+
| {{Type|Byte}}
| class="col2 centeralign" | <code>1</code>
+
| Notchian client displays effect level as Amplifier + 1.
| class="col3" | If mode is 0 the client will unload the chunk, otherwise the client will initialize the chunk
+
|-
|- class="row4"
+
| Duration
! class="col0" | Total Size:
+
| {{Type|VarInt}}
| class="col1 rightalign" colspan="4" | 10 bytes
+
| Duration in ticks. (-1 for infinite)
|}
+
|-
 +
| Flags
 +
| {{Type|Byte}}
 +
| Bit field, see below.
 +
|-
 +
| Has Factor Data
 +
| {{Type|Boolean}}
 +
| Used in DARKNESS effect
 +
|-
 +
| Factor Codec
 +
| {{Type|NBT}}
 +
| See below
 +
|}
  
=== Map Chunks (0x33) ===
+
Within flags:
  
Chunks are sent a column at a time, with some chunks optionally missing from each packet (those consisting only of air).
+
* 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 [[Entity_metadata#Living Entity|"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.
  
 +
Factor Data
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
!Name
! class="col0" | Packet ID
+
!Type
! class="col1" | Field Name
+
!style="width: 250px;" colspan="2"| Notes
! class="col2" | Field Type
+
|-
! class="col3" | Example
+
| padding_duration
! class="col4" | Notes
+
| TAG_INT
|- class="row1"
+
|
| class="col0 centeralign" rowspan="8" | 0x33
+
|-
| class="col1 centeralign" | X
+
| factor_start
| class="col2 centeralign" | int
+
| TAG_FLOAT
| class="col3 centeralign" |
+
|
| class="col4" | Column X Coordinate (*16 to get true X)
+
|-
|- class="row2"
+
| factor_target
| class="col0 centeralign" | Z
+
| TAG_FLOAT
| class="col1 centeralign" | int
+
|
| class="col2 centeralign" |
+
|-
| class="col3" | Column Z Coordinate (*16 to get true Z)
+
| factor_current
|- class="row3"
+
| TAG_FLOAT
| class="col0 centeralign" | Ground-up continuous
+
|
| class="col1 centeralign" | boolean
+
|-
| class="col2 centeralign" |
+
| effect_changed_timestamp
| class="col3" | This is True if the packet represents all chunks in this vertical column of chunks, where the primary bit map specifies exactly which chunks are included, and which are air.
+
| TAG_INT
|- class="row4"
+
|-
| class="col0 centeralign" | Primary bit map
+
| factor_previous_frame
| class="col1 centeralign" | unsigned short
+
| TAG_FLOAT
| class="col2 centeralign" | 15
+
|-
| class="col3" | Bitmask with 1 for every 16x16x16 chunk which data follows in the compressed data.
+
| had_effect_last_tick
|- class="row5"
+
| TAG_BOOLEAN
| class="col0 centeralign" | Add bit map
+
|}
| class="col1 centeralign" | unsigned short
 
| class="col2 centeralign" | 0
 
| class="col3" | Same as above, but this is used exclusively for the 'add' portion of the payload
 
|- class="row6"
 
| class="col0 centeralign" | Compressed size
 
| class="col1 centeralign" | int
 
| class="col2 centeralign" |
 
| class="col3" | Size of compressed region data.
 
|- class="row7"
 
| class="col0 centeralign" | Unused int
 
| class="col1 centeralign" | int
 
| class="col2 centeralign" | 0
 
| class="col3" | Doesn't seem to be used by the client. Always 0. I expect this is Mod API stuff.
 
|- class="row8"
 
| class="col0 centeralign" | Compressed data
 
| class="col1 centeralign" | unsigned 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" | 22 bytes + Compressed chunk size
 
|}
 
  
The payload is a set of 16x16x16 chunks, sharing the same X and Z chunk coordinates. What is and isn't sent is provided by the two bitmask fields. The least significant bit is '1' if the chunk spanning from Y=0 to Y=15 is not completely air, and so forth. For block IDs, metadata, and lighting, the primary bitmask is used. A secondary bitmask is used for 'add' data, which is Mojang's means of provided Block IDs past 256. In vanilla minecraft, you can expect this to always be zero.  The chunks included in this packet progress from bottom to top, where Y=0 is the bottom.
+
==== Update Recipes ====
  
The data is compressed using the deflate() function in [http://www.zlib.net/ zlib]. After uncompressing, the data consists of five (or six) sequential sections, in order:
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! colspan="2"| Field Name
 +
! colspan="2"| Field Type
 +
! Notes
 +
|-
 +
| rowspan="4"| 0x73
 +
| rowspan="4"| Play
 +
| rowspan="4"| Client
 +
| colspan="2"| Num Recipes
 +
| colspan="2"| {{Type|VarInt}}
 +
| Number of elements in the following array.
 +
|-
 +
| rowspan="3"| Recipe
 +
| Type
 +
| rowspan="3"| {{Type|Array}}
 +
| {{Type|Identifier}}
 +
| The recipe type, see below.
 +
|-
 +
| Recipe ID
 +
| {{Type|Identifier}}
 +
|
 +
|-
 +
| Data
 +
| Varies
 +
| Additional data for the recipe.
 +
|}
  
* Block type array (1 byte per block, 4096 bytes per chunk)
+
Recipe types:
* Block metadata array (half byte per block, 2048 bytes per chunk)
 
* Block light array (half byte per block, 2048 bytes per chunk)
 
* Sky light array (half byte per block, 2048 bytes per chunk)
 
* Add array (half byte per block, 2048 bytes per chunk, uses second bitmask)
 
* Biome array (1 byte per XZ column, 256 bytes total, only sent if 'ground up continuous' is true)
 
  
Each section is the concatenated data of all included chunks (i.e. the block type array contains the block types of all included chunks).
+
{| class="wikitable"
 +
! Type
 +
! Description
 +
! Data
 +
|-
 +
| <code>minecraft: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
 +
    | {{Type|String}} (32767)
 +
    | Used to group similar recipes together in the recipe book. Tag is present in recipe JSON.
 +
    |-
 +
    |Category
 +
    |{{Type|VarInt}} {{Type|Enum}}
 +
    |Building = 0, Redstone = 1, Equipment = 2, Misc = 3
 +
    |-
 +
    | Ingredient count
 +
    | {{Type|VarInt}}
 +
    | Number of elements in the following array.
 +
    |-
 +
    | Ingredients
 +
    | {{Type|Array}} of Ingredient.
 +
    |
 +
    |-
 +
    | Result
 +
    | {{Type|Slot}}
 +
    |
 +
    |}
 +
|-
 +
| <code>minecraft: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
 +
    |-
 +
    | Group
 +
    | {{Type|String}} (32767)
 +
    | Used to group similar recipes together in the recipe book. Tag is present in recipe JSON.
 +
    |-
 +
    |Category
 +
    |{{Type|VarInt}} {{Type|Enum}}
 +
    |Building = 0, Redstone = 1, Equipment = 2, Misc = 3
 +
    |-
 +
    | Width
 +
    | {{Type|VarInt}}
 +
    |
 +
    |-
 +
    | Height
 +
    | {{Type|VarInt}}
 +
    |
 +
    |-
 +
    | Ingredients
 +
    | {{Type|Array}} of Ingredient
 +
    | Length is <code>width * height</code>. Indexed by <code>x + (y * width)</code>.
 +
    |-
 +
    | Result
 +
    | {{Type|Slot}}
 +
    |-
 +
    | Show notification
 +
    | {{Type|Boolean}}
 +
    | Show a toast when the recipe is [[Protocol#Update_Recipe_Book|added]].
 +
    |}
 +
|-
 +
| <code>minecraft:crafting_special_armordye</code>
 +
| Recipe for dying leather armor
 +
| rowspan="14" | As follows:
 +
  {| class="wikitable"
 +
    ! Name
 +
    ! Type
 +
    ! Description
 +
    |-
 +
    |Category
 +
    |{{Type|VarInt}} {{Type|Enum}}
 +
    |Building = 0, Redstone = 1, Equipment = 2, Misc = 3
 +
    |}
 +
|-
 +
| <code>minecraft:crafting_special_bookcloning</code>
 +
| Recipe for copying contents of written books
 +
|-
 +
| <code>minecraft:crafting_special_mapcloning</code>
 +
| Recipe for copying maps
 +
|-
 +
| <code>minecraft:crafting_special_mapextending</code>
 +
| Recipe for adding paper to maps
 +
|-
 +
| <code>minecraft:crafting_special_firework_rocket</code>
 +
| Recipe for making firework rockets
 +
|-
 +
| <code>minecraft:crafting_special_firework_star</code>
 +
| Recipe for making firework stars
 +
|-
 +
| <code>minecraft:crafting_special_firework_star_fade</code>
 +
| Recipe for making firework stars fade between multiple colors
 +
|-
 +
| <code>minecraft:crafting_special_repairitem</code>
 +
| Recipe for repairing items via crafting
 +
|-
 +
| <code>minecraft:crafting_special_tippedarrow</code>
 +
| Recipe for crafting tipped arrows
 +
|-
 +
| <code>minecraft:crafting_special_bannerduplicate</code>
 +
| Recipe for copying banner patterns
 +
|-
 +
| <code>minecraft:crafting_special_shielddecoration</code>
 +
| Recipe for applying a banner's pattern to a shield
 +
|-
 +
| <code>minecraft:crafting_special_shulkerboxcoloring</code>
 +
| Recipe for recoloring a shulker box
 +
|-
 +
| <code>minecraft:crafting_special_suspiciousstew</code>
 +
| Recipe for crafting suspicious stews
 +
|-
 +
| <code>minecraft:crafting_decorated_pot</code>
 +
| Recipe for crafting decorated pots
 +
|-
 +
| <code>minecraft:smelting</code>
 +
| Smelting recipe
 +
| rowspan="4"| As follows:
 +
  {| class="wikitable"
 +
    ! Name
 +
    ! Type
 +
    ! Description
 +
    |-
 +
    | Group
 +
    | {{Type|String}} (32767)
 +
    | Used to group similar recipes together in the recipe book.
 +
    |-
 +
    |Category
 +
    |{{Type|VarInt}} {{Type|Enum}}
 +
    |Food = 0, Blocks = 1, Misc = 2
 +
    |-
 +
    | Ingredient
 +
    | Ingredient
 +
    |
 +
    |-
 +
    | Result
 +
    | {{Type|Slot}}
 +
    |
 +
    |-
 +
    | Experience
 +
    | {{Type|Float}}
 +
    |
 +
    |-
 +
    | Cooking time
 +
    | {{Type|VarInt}}
 +
    |
 +
    |}
 +
|-
 +
| <code>minecraft:blasting</code>
 +
| Blast furnace recipe
 +
|-
 +
| <code>minecraft:smoking</code>
 +
| Smoker recipe
 +
|-
 +
| <code>minecraft:campfire_cooking</code>
 +
| Campfire recipe
 +
|-
 +
| <code>minecraft:stonecutting</code>
 +
| Stonecutter recipe
 +
| As follows:
 +
  {| class="wikitable"
 +
    ! Name
 +
    ! Type
 +
    ! Description
 +
    |-
 +
    | Group
 +
    | {{Type|String}} (32767)
 +
    | Used to group similar recipes together in the recipe book.  Tag is present in recipe JSON.
 +
    |-
 +
    | Ingredient
 +
    | Ingredient
 +
    |
 +
    |-
 +
    | Result
 +
    | {{Type|Slot}}
 +
    |
 +
    |}
 +
|-
 +
| <code>minecraft:smithing_transform</code>
 +
| Recipe for smithing netherite gear
 +
| As follows:
 +
  {| class="wikitable"
 +
    ! Name
 +
    ! Type
 +
    ! Description
 +
    |-
 +
    | Template
 +
    | Ingredient
 +
    | The smithing template.
 +
    |-
 +
    | Base
 +
    | Ingredient
 +
    | The base item.
 +
    |-
 +
    | Addition
 +
    | Ingredient
 +
    | The additional ingredient.
 +
    |-
 +
    | Result
 +
    | {{Type|Slot}}
 +
    |
 +
    |}
 +
|-
 +
| <code>minecraft:smithing_trim</code>
 +
| Recipe for applying armor trims
 +
| As follows:
 +
  {| class="wikitable"
 +
    ! Name
 +
    ! Type
 +
    ! Description
 +
    |-
 +
    | Template
 +
    | Ingredient
 +
    | The smithing template.
 +
    |-
 +
    | Base
 +
    | Ingredient
 +
    | The base item.
 +
    |-
 +
    | Addition
 +
    | Ingredient
 +
    | The additional ingredient.
 +
    |}
 +
|}
  
In each section except biome data, your loop should look something like this:
+
Ingredient is defined as:
<code>
 
  //Loop over 16x16x16 chunks in the 16x256x16 column
 
  for (i=0;i<16;i++) {
 
    //If the bitmask indicates this chunk has been sent...
 
    if (bitmask & 1 << i) {
 
      //Read data...
 
      cubic_chunk_data = io.read(4096); //2048 for the other arrays, where you'll need to split the data
 
     
 
      for(int j=0; j<len(cubic_chunk_data); j++) {
 
        //Retrieve x,y,z and data from each element in cubic_chunk_array
 
       
 
        //Byte arrays
 
        x = chunk_x*16 + (j & 0xF0) >> 4;
 
        y = i*16      + j & 0x0F;
 
        z = chunk_z*16 + j >> 8;
 
        data = cubic_chunk_data[j]
 
       
 
        //Nibble arrays
 
        data1 = cubic_chunk_data[j] & 0x0F;
 
        data2 = cubic_chunk_data[j] >> 4;
 
       
 
        k = 2*j;
 
        x1 = chunk_x*16 + (k & 0xF0) >> 4;
 
        y1 = i*16      + k & 0x0F;
 
        z1 = chunk_z*16 + k >> 8;
 
       
 
        k++;
 
        x2 = chunk_x*16 + (k & 0xF0) >> 4;
 
        y2 = i*16      + k & 0x0F;
 
        z2 = chunk_z*16 + k >> 8;
 
      }
 
    }
 
  }
 
</code>
 
  
Each biome byte can have the values from 0 to 22, higher will cause the client to crash.
+
{| class="wikitable"
 +
! Name
 +
! Type
 +
! Description
 +
|-
 +
| Count
 +
| {{Type|VarInt}}
 +
| Number of elements in the following array.
 +
|-
 +
| Items
 +
| {{Type|Array}} of {{Type|Slot}}
 +
| Any item in this array may be used for the recipe.  The count of each item should be 1.
 +
|}
  
The 'add' array uses the second bitmask. Block IDs are presumed to be <code>block_id | add << 8</code>
+
==== Update Tags (play) ====
  
=== Multi Block Change (0x34) ===
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! colspan="2"| Field Name
 +
! colspan="2"| Field Type
 +
! Notes
 +
|-
 +
| rowspan="3"| 0x74
 +
| rowspan="3"| Play
 +
| rowspan="3"| Client
 +
| colspan="2"| Length of the array
 +
| colspan="2"| {{Type|VarInt}}
 +
|
 +
|-
 +
| rowspan="2"| Array of tags
 +
| Registry
 +
| rowspan="2"| {{Type|Array}}
 +
| {{Type|Identifier}}
 +
| Registry identifier (Vanilla expects tags for the registries <code>minecraft:block</code>, <code>minecraft:item</code>, <code>minecraft:fluid</code>, <code>minecraft:entity_type</code>, and <code>minecraft:game_event</code>)
 +
|-
 +
| Array of Tag
 +
| (See below)
 +
|
 +
|}
  
Like 0x33, this follows a new format. Arrays are now interlaced rather than sequential!
+
Tag arrays look like:
  
 
{| 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"| Length
! class="col4" | Notes
+
| colspan="2"| {{Type|VarInt}}
|- class="row1"
+
| Number of elements in the following array
| class="col0 centeralign" rowspan="5" | 0x34
+
|-
| class="col1 centeralign" | Chunk X
+
| rowspan="3"| Tags
| class="col2 centeralign" | inta
+
| Tag name
| class="col3 centeralign" | <code>-9</code>
+
| rowspan="3"| {{Type|Array}}
| class="col4" | Chunk X Coordinate
+
| {{Type|Identifier}}
|- class="row2"
+
|
| class="col0 centeralign" | Chunk Z
+
|-
| class="col1 centeralign" | int
+
| Count
| class="col2 centeralign" | <code>12</code>
+
| {{Type|VarInt}}
| class="col3" | Chunk Z Coordinate
+
| Number of elements in the following array
|- class="row3"
+
|-
| class="col0 centeralign" | Record count
+
| Entries
| class="col1 centeralign" | short
+
| {{Type|Array}} of {{Type|VarInt}}
| class="col2 centeralign" |  
+
| Numeric IDs of the given type (block, item, etc.). This list replaces the previous list of IDs for the given tag. If some preexisting tags are left unmentioned, a warning is printed.
| class="col3" | The number of blocks affected
+
|}
|- class="row2"
+
 
| class="col0 centeralign" | Data size
+
See {{Minecraft Wiki|Tag}} on the Minecraft Wiki for more information, including a list of vanilla tags.
| class="col1 centeralign" | int
+
 
| class="col2 centeralign" |  
+
=== Serverbound ===
| class="col3" | The total size of the data, in bytes. Should always be 4*record count - please confirm.
+
 
|- class="row4"
+
==== Confirm Teleportation ====
| class="col0 centeralign" | Data
 
| class="col1 centeralign" |
 
| class="col2 centeralign" | <code>…</code>
 
| class="col3" | Coordinates, type, and metadata of blocks to change.
 
|- class="row5"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 15 bytes + Arrays
 
|}
 
  
Each record is four bytes.
+
Sent by client as confirmation of [[#Synchronize Player Position|Synchronize Player Position]].
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Bit mask
+
! State
! class="col1" | Width
+
! Bound To
! class="col2" | Meaning
+
! Field Name
|- class="row1"
+
! Field Type
| class="col0" | 00 00 00 0F
+
! Notes
| class="col1" | 4 bits
+
|-
| class="col2" | Block metadata
+
| 0x00
|- class="row2"
+
| Play
| class="col0" | 00 00 FF F0
+
| Server
| class="col1" | 12 bits
+
| Teleport ID
| class="col2" | Block ID
+
| {{Type|VarInt}}
|- class="row3"
+
| The ID given by the [[#Synchronize Player Position|Synchronize Player Position]] packet.
| class="col0" | 00 FF 00 00
+
|}
| class="col1" | 8 bits
 
| class="col2" | Y co-ordinate
 
|- class="row4"
 
| class="col0" | 0F 00 00 00
 
| class="col1" | 4 bits
 
| class="col2" | Z co-ordinate, relative to chunk
 
|- class="row5"
 
| class="col0" | F0 00 00 00
 
| class="col1" | 4 bits
 
| class="col2" | X co-ordinate, relative to chunk
 
|}
 
  
=== Block Change (0x35) ===
+
==== Query Block Entity Tag ====
  
[[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.
+
Used when <kbd>F3</kbd>+<kbd>I</kbd> is pressed while looking at a 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="5" | 0x35
+
| rowspan="2"| 0x01
| class="col1 centeralign" | X
+
| rowspan="2"| Play
| class="col2 centeralign" | int
+
| rowspan="2"| Server
| class="col3 centeralign" | <code>502</code>
+
| Transaction ID
| class="col4" | Block X Coordinate
+
| {{Type|VarInt}}
|- class="row2"
+
| An incremental ID so that the client can verify that the response matches.
| class="col0 centeralign" | Y
+
|-
| class="col1 centeralign" | byte
+
| Location
| class="col2 centeralign" | <code>71</code>
+
| {{Type|Position}}
| class="col3" | Block Y Coordinate
+
| The location of the block to check.
|- class="row3"
+
|}
| class="col0 centeralign" | Z
+
 
| class="col1 centeralign" | int
+
==== Change Difficulty ====
| 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
 
|}
 
  
=== Block Action (0x36) ===
+
Must have at least op level 2 to use.  Appears to only be used on singleplayer; the difficulty buttons are still disabled in multiplayer.
  
'''Server to Client only'''
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x02
 +
| Play
 +
| Server
 +
| New difficulty
 +
| {{Type|Byte}}
 +
| 0: peaceful, 1: easy, 2: normal, 3: hard .
 +
|}
  
This packet is used for a number of things:
+
==== Acknowledge Message ====
* <div class="li">Chests opening and closing
 
* Pistons pushing and pulling
 
* Note blocks playing
 
  
 
{| 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" | 0x36
+
| rowspan="1"| 0x03
| class="col1 centeralign" | X
+
| rowspan="1"| Play
| class="col2 centeralign" | int
+
| rowspan="1"| Server
| class="col3 centeralign" | <code>502</code>
+
| Message Count
| class="col4" | Block X Coordinate
+
| {{Type|VarInt}}
|- class="row2"
+
|  
| class="col0 centeralign" | Y
+
|}
| class="col1 centeralign" | short
 
| class="col2 centeralign" | <code>71</code>
 
| class="col3" | Block Y Coordinate
 
|- class="row3"
 
| class="col0 centeralign" | Z
 
| class="col1 centeralign" | int
 
| class="col2 centeralign" | <code>18</code>
 
| class="col3" | Block Z Coordinate
 
|- class="row4"
 
| class="col0 centeralign" | Byte 1
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>3</code>
 
| class="col3" | Varies depending on block - see below
 
|- class="row5"
 
| class="col0 centeralign" | Byte 2
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" | <code>17</code>
 
| class="col3" | Varies depending on block - see below
 
|- class="row6"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 13 bytes
 
|}
 
  
==== Note Block ====
+
==== Chat Command ====
  
It shows the note particle being emitted from the block as well as playing the tone.
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! colspan="2"| Field Name
 +
! colspan="2"| Field Type
 +
! Notes
 +
|-
 +
| rowspan="8"| 0x04
 +
| rowspan="8"| Play
 +
| rowspan="8"| Server
 +
| colspan="2"| Command
 +
| colspan="2"| {{Type|String}} (256)
 +
| colspan="2"| The command typed by the client.
 +
|-
 +
| colspan="2"| Timestamp
 +
| colspan="2"| {{Type|Long}}
 +
| colspan="2"| The timestamp that the command was executed.
 +
|-
 +
| colspan="2"| Salt
 +
| colspan="2"| {{Type|Long}}
 +
| colspan="2"| The salt for the following argument signatures.
 +
|-
 +
| colspan="2"| Array length
 +
| colspan="2"| {{Type|VarInt}}
 +
| colspan="2"| Number of entries in the following array. The maximum length in Notchian server is 8.
 +
|-
 +
| rowspan="2"| Array of argument signatures
 +
| Argument name
 +
| rowspan="2"| {{Type|Array}} (8)
 +
| {{Type|String}} (16)
 +
| The name of the argument that is signed by the following signature.
 +
|-
 +
| Signature
 +
| {{Type|Byte Array}} (256)
 +
| The signature that verifies the argument. Always 256 bytes and is not length-prefixed.
 +
|-
 +
| colspan="2"| Message Count
 +
| colspan="2"| {{Type|VarInt}}
 +
| colspan="2"|
 +
|-
 +
| colspan="2"| Acknowledged
 +
| colspan="2"| {{Type|Fixed BitSet}} (20)
 +
| colspan="2"|
 +
|}
  
===== Byte 1 =====
+
==== Chat Message ====
  
Instrument type.
+
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.
 +
 
 +
The server will broadcast a [[#Player Chat Message|Player Chat Message]] packet with Chat Type <code>minecraft:chat</code> to all players that haven't disabled chat (including the player that sent the message). See [[Chat#Processing chat]] for more information.
  
 
{| 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="7"| 0x05
| class="col1" | Double Bass
+
| rowspan="7"| Play
|- class="row3"
+
| rowspan="7"| Server
| class="col0" | 2
+
| Message
| class="col1" | Snare Drum
+
| {{Type|String}} (256)
|- class="row4"
+
|
| class="col0" | 3
+
|-
| class="col1" | Clicks/Sticks
+
| Timestamp
|- class="row5"
+
| {{Type|Long}}
| class="col0" | 4
+
|
| class="col1" | Bass Drum
+
|-
|}
+
| Salt
 +
| {{Type|Long}}
 +
| The salt used to verify the signature hash.
 +
|-
 +
| Has Signature
 +
| {{Type|Boolean}}
 +
| Whether the next field is present.
 +
|-
 +
| Signature
 +
| {{Type|Optional}} {{Type|Byte Array}} (256)
 +
| The signature used to verify the chat message's authentication. When present, always 256 bytes and not length-prefixed.
 +
|-
 +
| Message Count
 +
| {{Type|VarInt}}
 +
|
 +
|-
 +
| Acknowledged
 +
| {{Type|Fixed BitSet}} (20)
 +
|  
 +
|}
  
===== Byte 2 =====
+
==== Player Session ====
  
The pitch of the note (between 0-24 inclusive where 0 is the lowest and 24 is the highest). 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].
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! colspan="2"| Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="6"| 0x06
 +
| rowspan="6"| Play
 +
| rowspan="6"| Server
 +
| colspan="2"| Session Id
 +
| {{Type|UUID}}
 +
|
 +
|-
 +
| rowspan="5"| Public Key
 +
| Expires At
 +
| {{Type|Long}}
 +
| The time the play session key expires in [https://en.wikipedia.org/wiki/Unix_time epoch] milliseconds.
 +
|-
 +
| Public Key Length
 +
| {{Type|VarInt}}
 +
| Length of the proceeding public key. Maximum length in Notchian server is 512 bytes.
 +
|-
 +
| Public Key
 +
| {{Type|Byte Array}} (512)
 +
| A byte array of an X.509-encoded public key.
 +
|-
 +
| Key Signature Length
 +
| {{Type|VarInt}}
 +
| Length of the proceeding key signature array. Maximum length in Notchian server is 4096 bytes.
 +
|-
 +
| Key Signature
 +
| {{Type|Byte Array}} (4096)
 +
| The signature consists of the player UUID, the key expiration timestamp, and the public key data. These values are hashed using [https://en.wikipedia.org/wiki/SHA-1 SHA-1] and signed using Mojang's private [https://en.wikipedia.org/wiki/RSA_(cryptosystem) RSA] key.
 +
|}
  
==== Piston ====
+
==== Chunk Batch Received ====
  
===== Byte 1 =====
+
Notifies the server that the chunk batch has been received by the client. The server uses the value sent in this packet to adjust the number of chunks to be sent in a batch.
  
The state the piston changes to - 0 for pushing, 1 for pulling.
+
The Notchian server will stop sending further chunk data until the client acknowledges the sent chunk batch. After the first acknowledgement, the server adjusts this number to allow up to 10 unacknowledged batches.
  
===== Byte 2 =====
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="1"| 0x07
 +
| rowspan="1"| Play
 +
| rowspan="1"| Server
 +
| Chunks per tick
 +
| {{Type|Float}}
 +
| Desired chunks per tick.
 +
|}
  
Direction.
+
==== Client Status ====
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Direction ID
+
! State
! class="col1" | Direction
+
! Bound To
|- class="row1"
+
! Field Name
| class="col0" | 0
+
! Field Type
| class="col1" | Down
+
! Notes
|- class="row2"
+
|-
| class="col0" | 1
+
| 0x08
| class="col1" | Up
+
| Play
|- class="row3"
+
| Server
| class="col0" | 2
+
| Action ID
| class="col1" | South
+
| {{Type|VarInt}} {{Type|Enum}}
|- class="row4"
+
| See below
| class="col0" | 3
+
|}
| class="col1" | West
 
|- class="row5"
 
| class="col0" | 4
 
| class="col1" | North
 
|- class="row5"
 
| class="col0" | 5
 
| class="col1" | East
 
|}
 
  
==== Chest ====
+
''Action ID'' values:
  
Animates the chest's lid opening. Note that the notchian server will send this every 3s even if the state hasn't changed.
+
{| 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.
 +
|}
  
===== Byte 1 =====
+
==== Client Information (play) ====
  
Not used - always 1
+
Sent when the player connects, or when settings are changed.
  
===== Byte 2 =====
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="8"| 0x09
 +
| rowspan="8"| Play
 +
| rowspan="8"| Server
 +
| Locale
 +
| {{Type|String}} (16)
 +
| e.g. <code>en_GB</code>.
 +
|-
 +
| View Distance
 +
| {{Type|Byte}}
 +
| Client-side render distance, in chunks.
 +
|-
 +
| Chat Mode
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| 0: enabled, 1: commands only, 2: hidden.  See [[Chat#Client chat mode]] for more information.
 +
|-
 +
| Chat Colors
 +
| {{Type|Boolean}}
 +
| “Colors” multiplayer setting. Can the chat be colored?
 +
|-
 +
| Displayed Skin Parts
 +
| {{Type|Unsigned Byte}}
 +
| Bit mask, see below.
 +
|-
 +
| Main Hand
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| 0: Left, 1: Right.
 +
|-
 +
| Enable text filtering
 +
| {{Type|Boolean}}
 +
| Enables filtering of text on signs and written book titles. Currently always false (i.e. the filtering is disabled)
 +
|-
 +
| Allow server listings
 +
| {{Type|Boolean}}
 +
| Servers usually list online players, this option should let you not show up in that list.
 +
|}
  
State of the chest - 0 for closed, 1 for open.
+
''Displayed Skin Parts'' flags:
  
=== Explosion (0x3C) ===
+
* 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
  
[[File:Icon_exclaim.gif|:!:]] This command is not fully understood.
+
The most significant bit (bit 7, 0x80) appears to be unused.
  
Seems to be sent when an explosion occurs (both creepers and TNT).
+
==== Command Suggestions Request ====
 +
 
 +
Sent when the client needs to tab-complete a <code>minecraft:ask_server</code> suggestion 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 | 0x3C
+
| rowspan="2"| 0x0A
| class="col1 centeralign" | X
+
| rowspan="2"| Play
| class="col2 centeralign" | double
+
| rowspan="2"| Server
| class="col3 centeralign" |  
+
| Transaction Id
| class="col4" |
+
| {{Type|VarInt}}
|- class="row1"
+
| The id of the transaction that the server will send back to the client in the response of this packet. Client generates this and increments it each time it sends another tab completion that doesn't get a response.
| class="col1 centeralign" | Y
+
|-
| class="col2 centeralign" | double
+
| Text
| class="col3 centeralign" |
+
| {{Type|String}} (32500)
| class="col4" |
+
| All text behind the cursor without the <code>/</code> (e.g. to the left of the cursor in left-to-right languages like English).
|- class="row1"
+
|}
| class="col1 centeralign" | Z
 
| class="col2 centeralign" | double
 
| class="col3 centeralign" |
 
| class="col4" |
 
|- class="row1"
 
| class="col1 centeralign" | Unknown
 
| class="col2 centeralign" | float
 
| class="col3 centeralign" | 3.0
 
| class="col4" | radius?
 
|- class="row2"
 
| class="col1 centeralign" | Record count
 
| class="col2 centeralign" | int
 
| class="col3 centeralign" |
 
| 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
 
|}
 
  
=== Sound/particle effect (0x3D) ===
+
==== Acknowledge Configuration ====
  
Sent when a client is to play a sound or particle effect.
+
Sent by the client upon receiving a [[#Start Configuration|Start Configuration]] packet from the server.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="1"| 0x0B
 +
| rowspan="1"| Play
 +
| rowspan="1"| Server
 +
| colspan="3"| ''no fields''
 +
|}
 +
 
 +
This packet switches the connection state to [[#Configuration|configuration]].
 +
 
 +
==== Click Container Button ====
 +
 
 +
Used when clicking on window buttons.  Until 1.14, this was only used by enchantment tables.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="2"| 0x0C
 +
| rowspan="2"| Play
 +
| rowspan="2"| Server
 +
| Window ID
 +
| {{Type|Byte}}
 +
| The ID of the window sent by [[#Open Screen|Open Screen]].
 +
|-
 +
| Button ID
 +
| {{Type|Byte}}
 +
| Meaning depends on window type; see below.
 +
|}
 +
 
 +
{| 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.
 +
|}
 +
 
 +
==== Click Container ====
 +
 
 +
This packet is sent by the client when the player 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
+
! colspan="2"| Field Name
! class="col3" | Example
+
! colspan="2"| Field Type
! class="col4" | Notes
+
! Notes
|- class="row1"
+
|-
| class="col0 centeralign" rowspan=5 | 0x3D
+
| rowspan="9"| 0x0D
| class="col1 centeralign" | Effect ID
+
| rowspan="9"| Play
| class="col2 centeralign" | int
+
| rowspan="9"| Server
| class="col3 centeralign" | 1003
+
| colspan="2"| Window ID
| class="col4" | The ID of the effect, see below.
+
| colspan="2"| {{Type|Unsigned Byte}}
|- class="row1"
+
| colspan="2"| The ID of the window which was clicked. 0 for player inventory. The server ignores any packets targeting a Window ID other than the current one, including ignoring 0 when any other window is open.
| class="col1 centeralign" | X
+
|-
| class="col2 centeralign" | int
+
| colspan="2"| State ID
| class="col3 centeralign" |  
+
| colspan="2"| {{Type|VarInt}}
| class="col4" | The X location of the effect.
+
| colspan="2"| The last received State ID from either a [[#Set Container Slot|Set Container Slot]] or a [[#Set Container Content|Set Container Content]] packet.
|- class="row1"
+
|-
| class="col1 centeralign" | Y
+
| colspan="2"| Slot
| class="col2 centeralign" | byte
+
| colspan="2"| {{Type|Short}}
| class="col3 centeralign" |  
+
| colspan="2"| The clicked slot number, see below.
| class="col4" | The Y location of the effect.
+
|-
|- class="row1"
+
| colspan="2"| Button
| class="col1 centeralign" | Z
+
| colspan="2"| {{Type|Byte}}
| class="col2 centeralign" | int
+
| colspan="2"| The button used in the click, see below.
| class="col3 centeralign" |  
+
|-
| class="col4" | The Z location of the effect.
+
| colspan="2"| Mode
|- class="row2"
+
| colspan="2"| {{Type|VarInt}} {{Type|Enum}}
| class="col1 centeralign" | Data
+
| colspan="2"| Inventory operation mode, see below.
| class="col2 centeralign" | int
+
|-
| class="col3 centeralign" | 0
+
| colspan="2"| Length of the array
| class="col4" | Extra data for certain effects, see below.
+
| colspan="2"| {{Type|VarInt}}
|- class="row4"
+
| colspan="2"| Maximum value for Notchian server is 128 slots.
! class="col0" | Total Size:
+
|-
| class="col1 rightalign" colspan="4" | 18 bytes
+
| rowspan="2"| Array of changed slots
|}
+
| Slot number
 +
| rowspan="2"| {{Type|Array}} (128)
 +
| {{Type|Short}}
 +
|
 +
|-
 +
| Slot data
 +
| {{Type|Slot}}
 +
| New data for this slot, in the client's opinion; see below.
 +
|-
 +
| colspan="2"| Carried item
 +
| colspan="2"| [[Slot Data|Slot]]
 +
| colspan="2"| Item carried by the cursor. Has to be empty (item ID = -1) for drop mode, otherwise nothing will happen.
 +
|}
  
==== Effects ====
+
See [[Inventory]] for further information about how slots are indexed.
 +
 
 +
After performing the action, the server compares the results to the slot change information included in the packet, as applied on top of the server's view of the container's state prior to the action. For any slots that do not match, it sends [[#Set Container Slot|Set Container Slot]] packets containing the correct results. If State ID does not match the last ID sent by the server, it will instead send a full [[#Set Container Content|Set Container Content]] to resynchronize the client.
 +
 
 +
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.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Mode
! class="col0" | Effect ID
+
! Button
! class="col1" | Name
+
! Slot
! class="col1" | Data
+
! Trigger
! class="col2" | Notes
+
|-
|- class="row1"
+
! rowspan="4"| 0
! class="col0" | 1000
+
| 0
| class="col1" | CLICK2
+
| Normal
| class="col1" |
+
| Left mouse click
| class="col2" |
+
|-
|- class="row2"
+
| 1
! class="col0" | 1001
+
| Normal
| class="col1" | CLICK1
+
| Right mouse click
| class="col1" |
+
|-
| class="col2" |  
+
| 0
|- class="row3"
+
| -999
! class="col0" | 1002
+
| Left click outside inventory (drop cursor stack)
| class="col1" | BOW_FIRE
+
|-
| class="col1" |
+
| 1
| class="col2" |  
+
| -999
|- class="row4"
+
| Right click outside inventory (drop cursor single item)
! class="col0" | 1003
+
|-
| class="col1" | DOOR_TOGGLE
+
! rowspan="2"| 1
| class="col1" |
+
| 0
| class="col2" |  
+
| Normal
|- class="row5"
+
| Shift + left mouse click
! class="col0" | 1004
+
|-
| class="col1" | EXTINGUISH
+
| 1
| class="col1" |
+
| Normal
| class="col2" |  
+
| Shift + right mouse click ''(identical behavior)''
|- class="row6"
+
|-
! class="col0" | 1005
+
! rowspan="7"| 2
| class="col1" | RECORD_PLAY
+
| 0
| class="col1" | Record ID [http://www.minecraftwiki.net/wiki/Music_Discs]
+
| Normal
| class="col2" |  
+
| Number key 1
|- class="row7"
+
|-
! class="col0" | 1007
+
| 1
| class="col1" | CHARGE
+
| Normal
| class="col1" |
+
| Number key 2
| class="col2" | Sound of ghast firing.
+
|-
|- class="row7"
+
| 2
! class="col0" | 1008
+
| Normal
| class="col1" | FIREBALL
+
| Number key 3
| class="col1" |
+
|-
| class="col2" | Sound of blaze firing
+
|
|- class="row7"
+
|
! class="col0" | 1009
+
|
| class="col1" | FIREBALL
+
|-
| class="col1" |
+
| 8
| class="col2" | Same as above
+
| Normal
|- class="row7"
+
| Number key 9
! class="col0" | 2000
+
|-
| class="col1" | SMOKE
+
|
| class="col2" | Direction, check below
+
|
| class="col3" |
+
| Button is used as the slot index (impossible in vanilla clients)
|- class="row8"
+
|-
! class="col0" | 2001
+
| 40
| class="col1" | BLOCK_BREAK
+
| Normal
| class="col2" | Block ID broken
+
| Offhand swap key F
| class="col3" |
+
|-
|- class="row8"
+
! 3
! class="col0" | 2002
+
| 2
| class="col1" | SPLASH_POTION
+
| Normal
| class="col2" | Potion ID [http://www.lb-stuff.com/Minecraft/PotionDataValues1.9pre3.txt]
+
| Middle click, only defined for creative players in non-player inventories.
| class="col3" | Particle animation and sound
+
|-
|- class="row8"
+
! rowspan="2"| 4
! class="col0" | 2003
+
| 0
| class="col1" | PORTAL
+
| Normal*
| class="col2" |
+
| Drop key (Q) (* Clicked item is always empty)
| class="col3" | Particle animation
+
|-
|- class="row8"
+
| 1
! class="col0" | 2004
+
| Normal*
| class="col1" | BLAZE (?)
+
| Control + Drop key (Q) (* Clicked item is always empty)
| class="col1" |
+
|-
| class="col2" | Particle animation (fire + smoke)
+
! 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.
 +
|-
 +
| 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.
 +
|-
 +
| 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.
 +
|-
 +
! rowspan="2"| 6
 +
| 0
 +
| Normal
 +
| Double click
 +
|-
 +
| 1
 +
| Normal
 +
| Pickup all but check items in reverse order (impossible in vanilla clients)
 +
|}
  
Smoke directions:
+
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.
 +
 
 +
==== Close Container ====
 +
 
 +
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 Screen|Open Screen]] packet for the inventory.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x0E
 +
| Play
 +
| Server
 +
| Window ID
 +
| {{Type|Unsigned Byte}}
 +
| This is the ID of the window that was closed. 0 for player inventory.
 +
|}
 +
 
 +
==== Change Container Slot State ====
 +
 
 +
This packet is sent by the client when toggling the state of a Crafter.
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | ID
+
! State
! class="col1" | Direction
+
! Bound To
|- class="row1"
+
! Field Name
| class="col0" | 0
+
! Field Type
| class="col1" | South - East
+
! Notes
|- class="row2"
+
|-
| class="col0" | 1
+
| rowspan="3"| 0x0F
| class="col1" | South
+
| rowspan="3"| Play
|- class="row3"
+
| rowspan="3"| Server
| class="col0" | 2
+
| Slot ID
| class="col1" | South - West
+
| {{Type|VarInt}}
|- class="row4"
+
| This is the ID of the slot that was changed.
| class="col0" | 3
+
|-
| class="col1" | East
+
| Window ID
|- class="row5"
+
| {{Type|VarInt}}
| class="col0" | 4
+
| This is the ID of the window that was changed.
| class="col1" | (Up or middle ?)
+
|-
|- class="row6"
+
| State
| class="col0" | 5
+
| {{Type|Boolean}}
| class="col1" | West
+
| The new state of the slot. True for enabled, false for disabled.
|- class="row7"
+
|}
| class="col0" | 6
+
 
| class="col1" | North - East
+
==== Serverbound Plugin Message (play) ====
|- class="row8"
+
 
| class="col0" | 7
+
{{Main|Plugin channels}}
| class="col1" | North
+
 
|- class="row9"
+
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.
| class="col0" | 8
+
 
| class="col1" | North - West
+
More documentation on this: [https://dinnerbone.com/blog/2012/01/13/minecraft-plugin-channels-messaging/ https://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.
  
=== New/Invalid State (0x46) ===
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="2"| 0x10
 +
| rowspan="2"| Play
 +
| rowspan="2"| Server
 +
| Channel
 +
| {{Type|Identifier}}
 +
| Name of the [[plugin channel]] used to send the data.
 +
|-
 +
| Data
 +
| {{Type|Byte Array}} (32767)
 +
| 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.
 +
|}
  
This packet appeared with protocol version 10. Currently, it appears when a bed can't be used as a spawn point and when the rain state changes.  it could have additional uses in the future.
+
In Notchian server, the maximum data length is 32767 bytes.
  
The class has an array of strings linked to reason codes 0, 1, 2, and 3 but only the codes for 1 and 2 are null.
+
==== Edit Book ====
  
 
{| 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" | 0x46
+
| rowspan="5"| 0x11
| class="col1 centeralign" | Reason
+
| rowspan="5"| Play
| class="col2 centeralign" | byte
+
| rowspan="5"| Server
| class="col3 centeralign" | 0
+
| Slot
| class="col4" |
+
| {{Type|VarInt}}
|- class="row2"
+
| The hotbar slot where the written book is located
| class="col1 centeralign" | Game mode
+
|-
| class="col2 centeralign" | byte
+
| Count
| class="col3 centeralign" | 0
+
| {{Type|VarInt}}
| class="col4" | Used only when reason = 3. 0 is survival, 1 is creative.
+
| Number of elements in the following array. Maximum array size is 200.
|- class="row3"
+
|-
! class="col0" | Total Size:
+
| Entries
| class="col1 rightalign" colspan="4" | 3 bytes
+
| {{Type|Array}} (200) of {{Type|String}} (8192)
|}
+
| Text from each page. Maximum string length is 8192 chars.
 +
|-
 +
| Has title
 +
| {{Type|Boolean}}
 +
| If true, the next field is present. true if book is being signed, false if book is being edited.
 +
|-
 +
| Title
 +
| {{Type|Optional}} {{Type|String}} (128)
 +
| Title of book.
 +
|}
  
==== Reason codes ====
+
==== Query Entity Tag ====
 +
 
 +
Used when <kbd>F3</kbd>+<kbd>I</kbd> is pressed while looking at an entity.
  
 
{| class="wikitable"
 
{| class="wikitable"
|-
+
! Packet ID
! Code
+
! State
! Effect
+
! Bound To
! Text
+
! Field Name
|-
+
! Field Type
| 0
+
! Notes
| Invalid Bed
+
|-
| "tile.bed.notValid"
+
| rowspan="2"| 0x12
|-
+
| rowspan="2"| Play
| 1
+
| rowspan="2"| Server
| Begin raining
+
| Transaction ID
| null
+
| {{Type|VarInt}}
|-
+
| An incremental ID so that the client can verify that the response matches.
| 2
+
|-
| End raining
+
| Entity ID
| null
+
| {{Type|VarInt}}
|-
+
| The ID of the entity to query.
| 3
+
|}
| Change game mode
 
| gameMode.changed
 
|-
 
| 4
 
| Enter credits
 
|  
 
|}
 
  
=== Thunderbolt (0x47) ===
+
==== Interact ====
 +
 
 +
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.
  
'''Server to Client only'''
+
The target X, Y, and Z fields represent the difference between the vector location of the cursor at the time of the packet and the entity's position.
  
With this packet, the server notifies the client of thunderbolts striking somewhere (near the player?). The coordinates specify where exactly the thunderbolt strikes.
+
Note that middle-click in creative mode is interpreted by the client and sent as a [[#Set Creative Mode Slot|Set Creative Mode Slot]] packet instead.
  
 
{| 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 | 0x47
+
| rowspan="7"| 0x13
| class="col1 centeralign" | Entity ID
+
| rowspan="7"| Play
| class="col2 centeralign" | int
+
| rowspan="7"| Server
| class="col3 centeralign" | 4
+
| Entity ID
| class="col4" | The entity ID of the thunderbolt
+
| {{Type|VarInt}}
|- class="row1"
+
| The ID of the entity to interact.
| class="col1 centeralign" | Unknown
+
|-
| class="col2 centeralign" | boolean
+
| Type
| class="col3 centeralign" | true
+
| {{Type|VarInt}} {{Type|Enum}}
| class="col4" | Always true. Might have a meaning in the future...
+
| 0: interact, 1: attack, 2: interact at.
|- class="row1"
+
|-
| class="col1 centeralign" | X
+
| Target X
| class="col2 centeralign" | int
+
| {{Type|Optional}} {{Type|Float}}
| class="col3 centeralign" | 133
+
| Only if Type is interact at.
| class="col4" | Thunderbolt X as Absolute Integer
+
|-
|- class="row1"
+
| Target Y
| class="col1 centeralign" | Y
+
| {{Type|Optional}} {{Type|Float}}
| class="col2 centeralign" | int
+
| Only if Type is interact at.
| class="col3 centeralign" | 913
+
|-
| class="col4" | Thunderbolt Y as Absolute Integer
+
| Target Z
|- class="row1"
+
| {{Type|Optional}} {{Type|Float}}
| class="col1 centeralign" | Z
+
| Only if Type is interact at.
| class="col2 centeralign" | int
+
|-
| class="col3 centeralign" | 63552
+
| Hand
| class="col4" | Thunderbolt Z as Absolute Integer
+
| {{Type|Optional}} {{Type|VarInt}} {{Type|Enum}}
|- class="row2"
+
| Only if Type is interact or interact at; 0: main hand, 1: off hand.
! class="col0" | Total Size:
+
|-
| class="col1 rightalign" colspan="4" | 18 bytes
+
| Sneaking
|}
+
| {{Type|Boolean}}
 +
| If the client is sneaking.
 +
|}
  
=== Open window (0x64) ===
+
==== Jigsaw Generate ====
  
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.
+
Sent when Generate is pressed on the {{Minecraft Wiki|Jigsaw Block}} interface.
  
 
{| 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"| 0x14
| class="col1 centeralign" | Window id
+
| rowspan="3"| Play
| class="col2 centeralign" | byte
+
| rowspan="3"| Server
| class="col3 centeralign" | 123
+
| Location
| class="col4" | A unique id number for the window to be displayed. Notchian server implementation is a counter, starting at 1.
+
| {{Type|Position}}
|- class="row1"
+
  | Block entity location.
| class="col1 centeralign" | Inventory Type
+
|-
| class="col2 centeralign" | byte
+
| Levels
| class="col3 centeralign" | 2
+
| {{Type|VarInt}}
| class="col4" | The window type to use for displayCheck below
+
| Value of the levels slider/max depth to generate.
|- class="row1"
+
  |-
| class="col1 centeralign" | Window title
+
| Keep Jigsaws
| class="col2 centeralign" | string
+
| {{Type|Boolean}}
| class="col3 centeralign" | <code>Chest</code>
+
|
| class="col4" | The title of the window.
+
|}
|- class="row1"
+
 
| class="col1 centeralign" | Number of Slots
+
==== Serverbound Keep Alive (play) ====
| 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" | 6 bytes + length of string
 
|}
 
  
The window titles sent by the Notchian server are "Chest", "Large chest", "Crafting", "Furnace", and "Trap". Notchian clients force window titles for some windows, like dispensers and furnaces, but other titles are customizable. However, the window title sent by the server is always used for chests. See [[Inventory#Windows|inventory windows]] for further information.
+
The server will frequently send out a keep-alive (see [[#Clientbound Keep Alive (play)|Clientbound Keep Alive]]), each containing a random ID. The client must respond with the same packet.
  
=== Close window (0x65) ===
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x15
 +
| Play
 +
| Server
 +
| Keep Alive ID
 +
| {{Type|Long}}
 +
|
 +
|}
  
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.
+
==== Lock Difficulty ====
  
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.  
+
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" | 0x65
+
| 0x16
| class="col1 centeralign" | Window id
+
| Play
| class="col2 centeralign" | byte
+
| Server
| class="col3 centeralign" | 0
+
| Locked
| class="col4" | This is the id of the window that was closed. 0 for inventory.
+
| {{Type|Boolean}}
|- class="row2"
+
|
! class="col0" | Total Size:
+
|}
| class="col1 rightalign" colspan="4" | 2 bytes
 
|}
 
  
=== Window click (0x66) ===
+
==== Set Player Position ====
  
'''Client to Server only'''
+
Updates the player's XYZ position on the server.
  
[[File:Icon_exclaim.gif|:!:]] This command is not fully understood.
+
If the player is in a vehicle, the position is ignored (but in case of [[#Set Player Position and Rotation|Set Player Position and Rotation]], the rotation is still used as normal). No validation steps other than value range clamping are performed in this case.
  
This packet is sent by the player when it clicks on a slot in a window.
+
If the player is sleeping, the position (or rotation) is not changed, and a [[#Synchronize Player Position|Synchronize Player Position]] is sent if the received position deviated from the server's view by more than a meter.
 +
 
 +
The Notchian server silently clamps the x and z coordinates between -30,000,000 and 30,000,000, and the y coordinate between -20,000,000 and 20,000,000. A similar condition has historically caused a kick for "Illegal position"; this is no longer the case. However, infinite or NaN coordinates (or angles) still result in a kick for <code>multiplayer.disconnect.invalid_player_movement</code>.
 +
 
 +
As of 1.20.4, checking for moving too fast is achieved like this (sic):
 +
 
 +
* Each server tick, the player's current position is stored.
 +
* When the player moves, the offset from the stored position to the requested position is computed (&Delta;x, &Delta;y, &Delta;z).
 +
* The requested movement distance squared is computed as &Delta;x&sup2; + &Delta;y&sup2; + &Delta;z&sup2;.
 +
* The baseline expected movement distance squared is computed based on  the player's server-side velocity as Vx&sup2; + Vy&sup2; + Vz&sup2;. The player's server-side velocity is a somewhat ill-defined quantity that includes among other things gravity, jump velocity and knockback, but ''not'' regular horizontal movement. A proper description would bring much of Minecraft's physics engine with it. It is accessible as the <code>Motion</code> NBT tag on the player entity.
 +
* The maximum permitted movement distance squared is computed as 100 (300 if the player is using an elytra), multiplied by the number of movement packets received since the last tick, including this one, unless that value is greater than 5, in which case no multiplier is applied.
 +
* If the requested movement distance squared minus the baseline distance squared is more than the maximum squared, the player is moving too fast.
 +
 
 +
If the player is moving too fast, it is logged that "<player> moved too quickly! " followed by the change in x, y, and z, and the player is teleported back to their current (before this packet) server-side position.
 +
 
 +
Checking for block collisions is achieved like this:
 +
 
 +
* A temporary collision-checked move of the player is attempted from its current position to the requested one.
 +
* The offset from the resulting position to the requested position is computed. If the absolute value of the offset on the y axis is less than 0.5, it (only the y component) is rounded down to 0.
 +
* If the magnitude of the offset is greater than 0.25 and the player isn't in creative or spectator mode, it is logged that "<player> moved wrongly!", and the player is teleported back to their current (before this packet) server-side position.
 +
* In addition, if the player's hitbox stationary at the requested position would intersect with a block, and they aren't in spectator mode, they are teleported back without a log message.
 +
 
 +
Checking for illegal flight is achieved like this:
 +
 
 +
* When a movement packet is received, a flag indicating whether or not the player is floating mid-air is updated. The flag is set if the move test described above detected no collision below the player ''and'' the y component of the offset from the player's current position to the requested one is greater than -0.5, unless any of various conditions permitting flight (creative mode, elytra, levitation effect, etc., but not jumping) are met.
 +
* Each server tick, it is checked if the flag has been set for more than 80 consecutive ticks. If so, and the player isn't currently sleeping, dead or riding a vehicle, they are kicked for <code>multiplayer.disconnect.flying</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=6 | 0x66
+
| rowspan="4"| 0x17
| class="col1 centeralign" | Window id
+
| rowspan="4"| Play
| class="col2 centeralign" | byte
+
| rowspan="4"| Server
| class="col3 centeralign" | <code>0</code>
+
| X
| class="col4" | The id of the window which was clicked. 0 for player inventory.
+
| {{Type|Double}}
|- class="row2"
+
| Absolute position.
| class="col0 centeralign" | Slot
+
|-
| class="col1 centeralign" | short
+
| Feet Y
| class="col2 centeralign" | <code>36</code>
+
| {{Type|Double}}
| class="col3" | The clicked slot. See below.
+
| Absolute feet position, normally Head Y - 1.62.
|- class="row3"
+
|-
| class="col0 centeralign" | Right-click
+
| Z
| class="col1 centeralign" | byte
+
| {{Type|Double}}
| class="col2 centeralign" | <code>1</code>
+
| Absolute position.
| class="col3" | 1 when right-clicking and otherwise 0.
+
|-
|- class="row4"
+
| On Ground
| class="col0 centeralign" | Action number
+
| {{Type|Boolean}}
| class="col1 centeralign" | short
+
| True if the client is on the ground, false otherwise.
| class="col2 centeralign" | <code>12</code>
+
|}
| class="col3" | A unique number for the action, used for transaction handling (See the Transaction packet).
+
 
|- class="row5"
+
==== Set Player Position and Rotation ====
| class="col0 centeralign" | Shift
 
| class="col1 centeralign" | bool
 
| class="col2 centeralign" | <code>0</code>
 
| class="col3" | This is true if the user was holding keyboard shift when they clicked.
 
|- class="row6"
 
| class="col0 centeralign" | Clicked item
 
| class="col1 centeralign" | [[Slot_Data|slot]]
 
| class="col2 centeralign" |
 
| class="col3" |
 
|- class="row7"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 8 bytes + slot data
 
|}
 
  
See [[Inventory#Windows|inventory windows]] for further information about how slots are indexed.
+
A combination of [[#Set Player Rotation|Move Player Rotation]] and [[#Set Player Position|Move Player Position]].
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="6"| 0x18
 +
| rowspan="6"| Play
 +
| rowspan="6"| Server
 +
| X
 +
| {{Type|Double}}
 +
| Absolute position.
 +
|-
 +
| Feet Y
 +
| {{Type|Double}}
 +
| Absolute feet position, normally Head Y - 1.62.
 +
|-
 +
| Z
 +
| {{Type|Double}}
 +
| Absolute position.
 +
|-
 +
| Yaw
 +
| {{Type|Float}}
 +
| Absolute rotation on the X Axis, in degrees.
 +
|-
 +
| Pitch
 +
| {{Type|Float}}
 +
| Absolute rotation on the Y Axis, in degrees.
 +
|-
 +
| On Ground
 +
| {{Type|Boolean}}
 +
| True if the client is on the ground, false otherwise.
 +
|}
 +
 
 +
==== Set Player Rotation ====
 +
[[File:Minecraft-trig-yaw.png|thumb|The unit circle for yaw]]
 +
[[File:Yaw.png|thumb|The unit circle of yaw, redrawn]]
  
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.
+
Updates the direction the player is looking in.
  
The Action number is actually a counter, starting at 1. This number is used by the server as a transaction ID to send back a [[Protocol#Transaction_.280x6A.29|Transaction packet]].
+
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.
  
=== Set slot (0x67) ===
+
Pitch is measured in degrees, where 0 is looking straight ahead, -90 is looking straight up, and 90 is looking straight down.
  
'''Server to Client only'''
+
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:
  
[[File:Icon_exclaim.gif|:!:]] This command is not fully understood.
+
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
  
Sent by the server when an item in a slot (in a window) is added/removed.
+
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)
  
 
{| 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 | 0x67
+
| rowspan="3"| 0x19
| class="col1 centeralign" | Window id
+
| rowspan="3"| Play
| class="col2 centeralign" | byte
+
| rowspan="3"| Server
| class="col3 centeralign" | <code>0</code>
+
| Yaw
| 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).
+
| {{Type|Float}}
|- class="row2"
+
| Absolute rotation on the X Axis, in degrees.
| class="col0 centeralign" | Slot
+
|-
| class="col1 centeralign" | short
+
| Pitch
| class="col2 centeralign" | <code>36</code>
+
| {{Type|Float}}
| class="col3" | The slot that should be updated
+
| Absolute rotation on the Y Axis, in degrees.
|- class="row3"
+
|-
| class="col0 centeralign" | Slot data
+
| On Ground
| class="col1 centeralign" | [[Slot_Data|slot]]
+
| {{Type|Boolean}}
| class="col2 centeralign" |
+
| True if the client is on the ground, false otherwise.
| class="col3" |
+
|}
|- class="row4"
+
 
! class="col0" | Total Size:
+
==== Set Player On Ground ====
| class="col1 rightalign" colspan="4" | 4 bytes + slot data
+
 
|}
+
This packet as well as [[#Set Player Position|Set Player Position]], [[#Set Player Rotation|Set Player Rotation]], and [[#Set Player Position and Rotation|Set Player Position and Rotation]] are called the “serverbound movement packets”. Vanilla clients will send Move Player Position once every 20 ticks even for a stationary player.
  
Note that if window ID and slot are both -1, it means the item currently attached to the cursor.
+
This packet is used to indicate whether the player is on ground (walking/swimming), or airborne (jumping/falling).
  
See [[Inventory#Windows|inventory windows]] for further information about how slots are indexed.
+
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.
  
Slots: [http://gyazo.com/9d52e1fd4dc14790ec66eab4a9aee00e.png]
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x1A
 +
| Play
 +
| Server
 +
| On Ground
 +
| {{Type|Boolean}}
 +
| True if the client is on the ground, false otherwise.
 +
|}
  
=== Window items (0x68) ===
+
==== Move Vehicle ====
  
'''Server to Client only'''
+
Sent when a player moves in a vehicle. Fields are the same as in [[#Set Player Position and Rotation|Set Player Position and Rotation]]. Note that all fields use absolute positioning and do not allow for relative positioning.
  
[[File:Inventory-slots.png|thumb|The inventory slots]]
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="5"| 0x1B
 +
| rowspan="5"| Play
 +
| rowspan="5"| Server
 +
| X
 +
| {{Type|Double}}
 +
| Absolute position (X coordinate).
 +
|-
 +
| Y
 +
| {{Type|Double}}
 +
| Absolute position (Y coordinate).
 +
|-
 +
| Z
 +
| {{Type|Double}}
 +
| Absolute position (Z coordinate).
 +
|-
 +
| Yaw
 +
| {{Type|Float}}
 +
| Absolute rotation on the vertical axis, in degrees.
 +
|-
 +
| Pitch
 +
| {{Type|Float}}
 +
| Absolute rotation on the horizontal axis, in degrees.
 +
|}
 +
 
 +
==== Paddle Boat ====
  
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.  
+
Used to ''visually'' update whether boat paddles are turning.  The server will update the [[Entity_metadata#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="3" | 0x68
+
| rowspan="2"| 0x1C
| class="col1 centeralign" | Window id
+
| rowspan="2"| Play
| class="col2 centeralign" | byte
+
| rowspan="2"| Server
| class="col3 centeralign" | <code>1</code>
+
| Left paddle turning
| class="col4" | The id of window which items are being sent for. 0 for player inventory.
+
| {{Type|Boolean}}
|- class="row2"
+
|
| class="col0 centeralign" | Count
+
|-
| class="col1 centeralign" | short
+
| Right paddle turning
| class="col2 centeralign" | <code>4</code>
+
| {{Type|Boolean}}
| class="col3" | The number of slots (see below)
+
|
|- class="row3"
+
|}
| class="col0 centeralign" | Slot data
 
| class="col1 centeralign" | array of [[Slot_Data|slots]]
 
| class="col2 centeralign" |
 
| class="col3" |
 
|- class="row4"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 4 bytes + size of slot data array
 
|}
 
  
See [[Inventory#Windows|inventory windows]] for further information about how slots are indexed.
+
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 held.
  
=== Update window property (0x69) ===
+
==== Pick Item ====
  
'''Server to Client only'''
+
Used to swap out an empty space on the hotbar with the item in the given inventory slot.  The Notchian client uses this for pick block functionality (middle click) to retrieve items from 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=3 | 0x69
+
| 0x1D
| class="col1 centeralign" | Window id
+
| Play
| class="col2 centeralign" | byte
+
| Server
| class="col3 centeralign" | 2
+
| Slot to use
| class="col4" | The id of the window.
+
| {{Type|VarInt}}
|- class="row1"
+
| See [[Inventory]].
| class="col1 centeralign" | Property
+
|}
| class="col2 centeralign" | short
 
| class="col3 centeralign" | 1
 
| class="col4" | Which property should be updated.
 
|- class="row1"
 
| class="col1 centeralign" | Value
 
| class="col2 centeralign" | short
 
| class="col3 centeralign" | 650
 
| class="col4" | The new value for the property.
 
|- class="row2"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 6 bytes
 
|}
 
  
==== Furnace ====
+
The server first searches 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 starts a second search from the current slot and finds the first slot that does not contain an enchanted item.  If there still are no slots that meet that criteria, then the server uses the currently selected slot.
  
Properties:
+
After finding the appropriate slot, the server swaps the items and sends 3 packets:
  
* 0: Progress arrow
+
* [[#Set Container Slot|Set Container Slot]] with window ID set to -2, updating the chosen hotbar slot.
* 1: Fire icon (fuel)
+
* [[#Set Container Slot|Set Container Slot]] with window ID set to -2, updating the slot where the picked item used to be.
 +
* [[#Set Held Item (clientbound)|Set Held Item]], switching to the newly chosen slot.
  
Values:
+
==== Ping Request (play) ====
  
* 0-180 for progress arrow
+
{| class="wikitable"
* 0-250 for fuel indicator
+
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x1E
 +
| Play
 +
| Server
 +
| Payload
 +
| {{Type|Long}}
 +
| May be any number. Notchian clients use a system-dependent time value which is counted in milliseconds.
 +
|}
  
Ranges are presumably in in-game ticks
+
==== Place Recipe ====
  
==== Enchantment Table ====
+
This packet is sent when a player clicks a recipe in the crafting book that is craftable (white border).
  
Properties: 0, 1 or 2 depending on the "enchantment slot" being given.
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="3"| 0x1F
 +
| rowspan="3"| Play
 +
| rowspan="3"| Server
 +
| Window ID
 +
| {{Type|Byte}}
 +
|
 +
|-
 +
| Recipe
 +
| {{Type|Identifier}}
 +
| A recipe ID.
 +
|-
 +
| Make all
 +
| {{Type|Boolean}}
 +
| Affects the amount of items processed; true if shift is down when clicked.
 +
|}
  
Values: The enchantment's level.
+
==== Player Abilities (serverbound) ====
  
=== Transaction (0x6A) ===
+
The vanilla client sends this packet when the player starts/stops flying with the Flags parameter changed accordingly.
  
A packet from the server indicating whether a request from the client was accepted, or whether there was a conflict (due to lag). This packet is also sent from the client to the server in response to a server transaction rejection packet.
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x20
 +
| Play
 +
| Server
 +
| Flags
 +
| {{Type|Byte}}
 +
| Bit mask. 0x02: is flying.
 +
|}
 +
 
 +
==== Player Action ====
 +
 
 +
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 the player's eyes.
  
 
{| 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="4"| 0x21
| class="col1 centeralign" | Window id
+
| rowspan="4"| Play
| class="col2 centeralign" | byte
+
| rowspan="4"| Server
| class="col3 centeralign" | 0
+
| Status
| class="col4" | The id of the window that the action occurred in.
+
| {{Type|VarInt}} {{Type|Enum}}
|- class="row1"
+
| The action the player is taking against the block (see below).
| class="col1 centeralign" | Action number
+
|-
| class="col2 centeralign" | short
+
| Location
| class="col3 centeralign" | 12
+
| {{Type|Position}}
| class="col4" | Every action that is to be accepted has a unique number. This field corresponds to that number.
+
| Block position.
|- class="row1"
+
|-
| class="col1 centeralign" | Accepted?
+
| Face
| class="col2 centeralign" | boolean
+
| {{Type|Byte}} {{Type|Enum}}
| class="col3 centeralign" | true
+
| The face being hit (see below).
| class="col4" | Whether the action was accepted.
+
|-
|- class="row2"
+
| Sequence
! class="col0" | Total Size:
+
| {{Type|VarInt}}
| class="col1 rightalign" colspan="4" | 5 bytes
+
| Block change sequence number (see [[#Acknowledge Block Change]]).
|}
+
|}
  
=== Creative inventory action (0x6B) ===
+
Status can be one of seven values:
  
While the user is in the standard inventory (i.e., not a crafting bench) on a creative-mode server then the server will send this packet:
+
{| class="wikitable"
 +
! Value
 +
! Meaning
 +
! Notes
 +
|-
 +
| 0
 +
| Started digging
 +
| Sent when the player starts digging a block. If the block was instamined or the player is in creative mode, the client will ''not'' send Status = Finished digging, and will assume the server completed the destruction. To detect this, it is necessary to {{Minecraft Wiki|Breaking#Speed|calculate the block destruction speed}} server-side.
 +
|-
 +
| 1
 +
| Cancelled digging
 +
| Sent when the player lets go of the Mine Block key (default: left click). Face is always set to -Y.
 +
|-
 +
| 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: Control or Command, depending on OS). Location is always set to 0/0/0, Face is always set to -Y. Sequence is always set to 0.
 +
|-
 +
| 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. Sequence is always set to 0.
 +
|-
 +
| 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. Sequence is always set to 0.
 +
|-
 +
| 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. Sequence is always set to 0.
 +
|}
  
* <div class="li"> If an item is dropped into the quick bar</div>
+
The Face field can be one of the following values, representing the face being hit:
* If an item is picked up from the quick bar (item id is -1)
 
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
|-
! class="col0" | Packet ID
+
! Value
! class="col1" | Field Name
+
! Offset
! class="col2" | Field Type
+
! Face
! class="col3" | Example
+
|-
! class="col4" | Notes
+
| 0
|- class="row1"
+
| -Y
| class="col0 centeralign" rowspan=2 | 0x6B
+
| Bottom
| class="col1 centeralign" | Slot
+
|-
| class="col2 centeralign" | short
+
| 1
| class="col3 centeralign" | 36
+
| +Y
| class="col4" | Inventory slot
+
| Top
|- class="row2"
+
|-
| class="col0 centeralign" | Clicked item
+
| 2
| class="col1 centeralign" | [[Slot_Data|slot]]
+
| -Z
| class="col2 centeralign" |
+
| North
| class="col3" |
+
|-
|- class="row3"
+
| 3
! class="col0" | Total Size:
+
| +Z
| class="col1 rightalign" colspan="4" | 3 bytes + slot data
+
| South
|}
+
|-
 +
| 4
 +
| -X
 +
| West
 +
|-
 +
| 5
 +
| +X
 +
| East
 +
|}
  
=== Enchant Item (0x6C) ===
+
==== Player Command ====
  
'''Client to Server only'''
+
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=2 | 0x6C
+
| rowspan="3"| 0x22
| class="col1 centeralign" | Window ID
+
| rowspan="3"| Play
| class="col2 centeralign" | byte
+
| rowspan="3"| Server
| class="col3 centeralign" | 1
+
| Entity ID
| class="col4" | The ID sent by [[Protocol#Open_window_.280x64.29|0x64]]
+
| {{Type|VarInt}}
|- class="row2"
+
| Player ID
| class="col1 centeralign" | Enchantment
+
|-
| class="col2 centeralign" | byte
+
| Action ID
| class="col3 centeralign" | 0
+
| {{Type|VarInt}} {{Type|Enum}}
| class="col4" | The position of the enchantment on the enchantment table window, starting with 0 as the topmost one.
+
| The ID of the action, see below.
|- class="row3"
+
|-
! class="col0" | Total Size:
+
| Jump Boost
| class="col1 rightalign" colspan="4" | 3 bytes
+
| {{Type|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.
 +
|}
  
=== Update Sign (0x82) ===
+
Action ID can be one of the following values:
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! ID
! class="col0" | Packet ID
+
! Action
! class="col1" | Field Name
+
|-
! class="col2" | Field Type
+
| 0
! class="col3" | Example
+
| Start sneaking
! class="col4" | Notes
+
|-
|- class="row1"
+
| 1
| class="col0 centeralign" rowspan=7 | 0x82
+
| Stop sneaking
| class="col1 centeralign" | X
+
|-
| class="col2 centeralign" | int
+
| 2
| class="col3 centeralign" | 128
+
| Leave bed
| class="col4" | Block X Coordinate
+
|-
|- class="row1"
+
| 3
| class="col1 centeralign" | Y
+
| Start sprinting
| class="col2 centeralign" | short
+
|-
| class="col3 centeralign" | 0
+
| 4
| class="col4" | Block Y Coordinate
+
| Stop sprinting
|- class="row1"
+
|-
| class="col1 centeralign" | Z
+
| 5
| class="col2 centeralign" | int
+
| Start jump with horse
| class="col3 centeralign" | -128
+
|-
| class="col4" | Block Z Coordinate
+
| 6
|- class="row1"
+
| Stop jump with horse
| class="col1 centeralign" | Text1
+
|-
| class="col2 centeralign" | string
+
| 7
| class="col3 centeralign" | <code>First line</code>
+
| Open vehicle inventory
| class="col4" | First line of text in the sign
+
|-
|- class="row1"
+
| 8
| class="col1 centeralign" | Text2
+
| Start flying with elytra
| 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
 
|}
 
  
This message is sent from the server to the client whenever a sign is discovered or created. This message is sent from the client to the server when the "Done" button is pushed after placing a sign. This message is NOT sent when a sign is destroyed or unloaded.
+
Leave bed is only sent when the “Leave Bed” button is clicked on the sleep GUI, not when waking up in the morning.
  
=== Item Data (0x83) ===
+
Open vehicle inventory is only sent when pressing the inventory key (default: E) while on a horse or chest boat — all other methods of opening such an inventory (involving right-clicking or shift-right-clicking it) do not use this packet.
  
'''Server to Client only'''
+
==== Player Input ====
  
Sent to specify complex data on an item; currently used only for maps.
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="3"| 0x23
 +
| rowspan="3"| Play
 +
| rowspan="3"| Server
 +
| Sideways
 +
| {{Type|Float}}
 +
| Positive to the left of the player.
 +
|-
 +
| Forward
 +
| {{Type|Float}}
 +
| Positive forward.
 +
|-
 +
| Flags
 +
| {{Type|Unsigned Byte}}
 +
| Bit mask. 0x1: jump, 0x2: unmount.
 +
|}
 +
 
 +
Also known as 'Input' packet.
 +
 
 +
==== Pong (play) ====
 +
 
 +
Response to the clientbound packet ([[#Ping (play)|Ping]]) with the same id.
  
 
{| 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" | 0x83
+
| 0x24
| class="col1 centeralign" | Item Type
+
| Play
| class="col2 centeralign" | short
+
| Server
| class="col3 centeralign" | <code>358</code>
+
| ID
| class="col4" | Type of item being modified
+
| {{Type|Int}}
|- class="row2"
+
| id is the same as the ping packet
| class="col0 centeralign" | Item ID
+
|}
| class="col1 centeralign" | short
+
 
| class="col2 centeralign" | <code>0</code>
+
==== Change Recipe Book Settings ====
| class="col3" | The ID (damage value) of the item being modified
 
|- class="row3"
 
| class="col0 centeralign" | Text length
 
| class="col1 centeralign" | unsigned byte
 
| class="col2 centeralign" | <code>35</code>
 
| class="col3" | Length of following byte array
 
|- class="row4"
 
| class="col0 centeralign" | Text
 
| class="col1 centeralign" | byte array
 
| class="col2 centeralign" | {0,0,0,20,20,20,20,20}
 
| class="col3" | ASCII text.
 
|- class="row9"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 6 bytes + Text length
 
|}
 
  
'''Maps'''
+
Replaces Recipe Book Data, type 1.
If the first byte of the text is 0, the next two bytes are X start and Y start and the rest of the bytes are the colors in that column.
 
  
If the first byte of the text is 1, the rest of the bytes are in groups of three: (data, x, y). The lower half of the data is the type (always 0 under vanilla) and the upper half is the direction.
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="3"| 0x25
 +
| rowspan="3"| Play
 +
| rowspan="3"| Server
 +
| Book ID
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| 0: crafting, 1: furnace, 2: blast furnace, 3: smoker.
 +
|-
 +
| Book Open
 +
| {{Type|Boolean}}
 +
|
 +
|-
 +
| Filter Active
 +
| {{Type|Boolean}}
 +
|
 +
|}
  
=== Update Tile Entity (0x84) ===
+
==== Set Seen Recipe ====
  
Essentially a block update on a tile entity.
+
Sent when recipe is first seen in recipe book. Replaces Recipe Book Data, type 0.
  
 
{| 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" | 0x84
+
| 0x26
| class="col1 centeralign" | X
+
| Play
| class="col2 centeralign" | int
+
| Server
| class="col3 centeralign" |
+
| Recipe ID
| class="col4" |
+
| {{Type|Identifier}}
|- class="row2"
+
|
| class="col0 centeralign" | Y
+
|}
| class="col1 centeralign" | short
 
| class="col2 centeralign" |
 
| class="col3" |
 
|- class="row3"
 
| class="col0 centeralign" | Z
 
| class="col1 centeralign" | int
 
| class="col2 centeralign" |
 
| class="col3" |
 
|- class="row4"
 
| class="col0 centeralign" | Action
 
| class="col1 centeralign" | byte
 
| class="col2 centeralign" |
 
| class="col3" | The type of update to perform
 
|- class="row5"
 
| class="col0 centeralign" | Custom 1
 
| class="col1 centeralign" | int
 
| class="col2 centeralign" |
 
| class="col3" | Varies
 
|- class="row6"
 
| class="col0 centeralign" | Custom 2
 
| class="col1 centeralign" | int
 
| class="col2 centeralign" |
 
| class="col3" | Varies
 
|- class="row7"
 
| class="col0 centeralign" | Custom 3
 
| class="col1 centeralign" | int
 
| class="col2 centeralign" |
 
| class="col3" | Varies
 
|- class="row8"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 24 bytes
 
|}
 
  
==== Actions ====
+
==== Rename Item ====
  
* '''1''': Set mob displayed inside a mob spawner. Custom 1 contains the [[Entities#Mobs|mob type]]
+
Sent as a player is renaming an item in an anvil (each keypress in the anvil UI sends a new Rename 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 50 characters long, and if it is longer than that, then the rename is silently ignored.
  
=== Increment Statistic (0xC8) ===
 
 
{| 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 | 0xC8
+
| 0x27
| class="col1 centeralign" | Statistic ID
+
| Play
| class="col2 centeralign" | int
+
| Server
| class="col3 centeralign" | 1003
+
| Item name
| class="col4" | The ID of the statistic. See [http://www.minecraftforum.net/viewtopic.php?f=1020&t=295360 List of statistics].
+
| {{Type|String}} (32767)
|- class="row1"
+
| The new name of the item.
| class="col1 centeralign" | Amount
+
|}
| class="col2 centeralign" | byte
+
 
| class="col3 centeralign" | 1
+
==== Resource Pack Response (play) ====
| class="col4" | The amount to increment the statistic.
 
|- class="row2"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 6 bytes
 
|}
 
  
=== Player List Item (0xC9) ===
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="3" | 0x28
 +
| rowspan="3" | Play
 +
| rowspan="3" | Server
 +
|-
 +
| UUID
 +
| {{Type|UUID}}
 +
| The unique identifier of the resource pack received in the [[#Add_Resource_Pack_(play)|Add Resource Pack (play)]] request.
 +
|-
 +
| Result
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| Result ID (see below).
 +
|}
  
Sent by the notchian server to update the user list (<tab> in the client). The server sends one packet per user per tick, amounting to 20 packets/s for 1 online user, 40 for 2, and so forth.
+
Result can be one of the following values:
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! ID
! class="col0" | Packet ID
+
! Result
! class="col1" | Field Name
+
|-
! class="col2" | Field Type
+
| 0
! class="col3" | Example
+
| Successfully downloaded
! class="col4" | Notes
+
|-
|- class="row1"
+
| 1
| class="col0 centeralign" rowspan=3 | 0xC9
+
| Declined
| class="col1 centeralign" | Player name
+
|-
| class="col2 centeralign" | string
+
| 2
| class="col3 centeralign" | barneygale
+
| Failed to download
| class="col4" | Supports chat colouring, limited to 16 characters.
+
|-
|- class="row2"
+
| 3
| class="col1 centeralign" | Online
+
| Accepted
| class="col2 centeralign" | bool
+
|-
| class="col3 centeralign" | true
+
| 4
| class="col4" | If false, the client will remove the user from the list.
+
| Invalid URL
|- class="row3"
+
|-
| class="col1 centeralign" | Ping
+
| 5
| class="col2 centeralign" | short
+
| Failed to reload
| class="col3 centeralign" | 193
+
|-
| class="col4" | Ping, presumably in ms.
+
| 6
|- class="row2"
+
| Discarded
! class="col0" | Total Size:
+
|}
| class="col1 rightalign" colspan="4" | 6 bytes + length of string
 
|}
 
  
=== Plugin message (0xFA) ===
 
  
Mods and plugins can use this to send their data.
+
==== Seen Advancements ====
  
 
{| 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 | 0xFA
+
| rowspan="2"| 0x29
| class="col1 centeralign" | Channel
+
| rowspan="2"| Play
| class="col2 centeralign" | string
+
| rowspan="2"| Server
| class="col3 centeralign" | MyMod:testchannel
+
| Action
| class="col4" | Name of the "channel" used to send the data.
+
| {{Type|VarInt}} {{Type|Enum}}
|- class="row2"
+
| 0: Opened tab, 1: Closed screen.
| class="col1 centeralign" | length
+
|-
| class="col2 centeralign" | short
+
| Tab ID
| class="col3 centeralign" |
+
| {{Type|Optional}} {{Type|Identifier}}
| class="col4" | Length of the following byte array
+
| Only present if action is Opened tab.
|- class="row3"
+
|}
| class="col1 centeralign" | data
 
| class="col2 centeralign" | byte array
 
| class="col3 centeralign" |  
 
| class="col4" | Any data.
 
|- class="row2"
 
! class="col0" | Total Size:
 
| class="col1 rightalign" colspan="4" | 4 bytes + length of string + length of byte array
 
|}
 
  
More documentation on this: http://dinnerbone.com/blog/2012/01/13/minecraft-plugin-channels-messaging/
+
==== Select Trade ====
 +
 
 +
When a player selects a specific trade offered by a villager NPC.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x2A
 +
| Play
 +
| Server
 +
| Selected slot
 +
| {{Type|VarInt}}
 +
| The selected slot in the players current (trading) inventory.
 +
|}
  
=== Server List Ping (0xFE) ===
+
==== Set Beacon Effect ====
  
To load server info in the multiplayer menu, the notchian client connects to each known server and sends an 0xFE.
+
Changes the effect of the current beacon.
  
In return, the server sends a kick (0xFF), with its string containing data (server description, number of users, number of slots), delimited by a UCS-2 '§' (0xA7).
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="5"| 0x2B
 +
| rowspan="5"| Play
 +
| rowspan="5"| Server
 +
|-
 +
| Has Primary Effect
 +
| {{Type|Boolean}}
 +
|-
 +
| Primary Effect
 +
| {{Type|VarInt}}
 +
| A [https://minecraft.wiki/w/Potion#ID Potion ID].
 +
|-
 +
| Has Secondary Effect
 +
| {{Type|Boolean}}
 +
|
 +
|-
 +
| Secondary Effect
 +
| {{Type|VarInt}}
 +
| A [https://minecraft.wiki/w/Potion#ID Potion ID].
 +
|}
  
Note that as this is the last packet you'll see, you can get away with just chopping off the first three bytes (the ident and the string length) and decoding the remainder as a UCS-2 string.
+
==== Set Held Item (serverbound) ====
  
If the number of available slots sent is equal to or less than 0, the client should display it as "???".  
+
Sent when the player changes the slot selection.
  
Example server pinger:
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x2C
 +
| Play
 +
| Server
 +
| Slot
 +
| {{Type|Short}}
 +
| The slot which the player has selected (0–8).
 +
|}
  
https://gist.github.com/1209061 (Python)
+
==== Program Command Block ====
  
https://gist.github.com/1235274 (PHP)
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="5"| 0x2D
 +
| rowspan="5"| Play
 +
| rowspan="5"| Server
 +
|-
 +
| Location
 +
| {{Type|Position}}
 +
|
 +
|-
 +
| Command
 +
| {{Type|String}} (32767)
 +
|
 +
|-
 +
| Mode || {{Type|VarInt}} {{Type|Enum}} || One of SEQUENCE (0), AUTO (1), or REDSTONE (2).
 +
|-
 +
| Flags
 +
| {{Type|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.
 +
|}
  
http://pastebin.com/q5zFPcXV  (Ruby)
+
==== Program Command Block Minecart ====
  
 
{| class="wikitable"
 
{| class="wikitable"
|- class="row0"
+
! Packet ID
! class="col0" | Packet ID
+
! State
|- class="row1"
+
! Bound To
| class="col0 centeralign" | 0xFE
+
! Field Name
|}
+
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="3"| 0x2E
 +
| rowspan="3"| Play
 +
| rowspan="3"| Server
 +
| Entity ID
 +
| {{Type|VarInt}}
 +
|
 +
|-
 +
| Command
 +
| {{Type|String}} (32767)
 +
|
 +
|-
 +
| Track Output
 +
| {{Type|Boolean}}
 +
| If false, the output of the previous command will not be stored within the command block.
 +
|}
  
=== Disconnect/Kick (0xFF) ===
+
==== Set Creative Mode Slot ====
  
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.
+
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).
  
 
{| 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
+
| rowspan="2"| 0x2F
| class="col1 centeralign" | Reason
+
| rowspan="2"| Play
| class="col2 centeralign" | string
+
| rowspan="2"| Server
| class="col3 centeralign" | <code>The server is full!</code>
+
| Slot
| class="col4" | Displayed to the client when the connection terminates
+
| {{Type|Short}}
|- class="row2"
+
| Inventory slot.
! class="col0" | Total Size:
+
|-
| class="col1 rightalign" colspan="4" | 3 bytes + length of strings
+
| Clicked Item
|}
+
| {{Type|Slot}}
 +
|
 +
|}
  
== Protocol History ==
+
==== Program Jigsaw Block ====
  
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.
+
Sent when Done is pressed on the {{Minecraft Wiki|Jigsaw Block}} interface.
  
=== 2012-03-01 ===
+
{| class="wikitable"
* 1.2.2
+
! Packet ID
* Protocol version is now 28
+
! State
* New packet: [[#Entity_Head_Look_.280x23.29|0x23 entity head look]]
+
! Bound To
* New packet: [[#Update_Tile_Entity_.280x84.29|0x84 update tile entity]]
+
! Field Name
* [[#Handshake_.280x02.29|0x02 handshake]] when sent C->S now additionally contains the hostname/port the client is connecting to
+
! Field Type
* [[#Login_Request_.280x01.29|0x01 login request]]: map seed (long) parameter removed and dimension changed from byte to int
+
! Notes
* [[#Respawn_.280x09.29|0x09 respawn]] has the same changes (dimension changed from byte to int and seed removed)
+
|-
* [[#Mob_Spawn_.280x18.29|0x18 mob spawn]] has a new byte field: head yaw
+
| rowspan="8"| 0x30
* [[#Map_Chunks_.280x33.29|0x33 map chunks]] packet was completely changed to use the new 16x16x16 chunk format
+
| rowspan="8"| Play
* [[#Multi_Block_Change_.280x34.29|0x34 multi block change]] has a new format also
+
| rowspan="8"| Server
 +
| Location
 +
| {{Type|Position}}
 +
| Block entity location
 +
|-
 +
| Name
 +
| {{Type|Identifier}}
 +
|
 +
|-
 +
| Target
 +
| {{Type|Identifier}}
 +
|
 +
|-
 +
| Pool
 +
| {{Type|Identifier}}
 +
|
 +
|-
 +
| Final state
 +
| {{Type|String}} (32767)
 +
| "Turns into" on the GUI, <code>final_state</code> in NBT.
 +
|-
 +
| Joint type
 +
| {{Type|String}} (32767)
 +
| <code>rollable</code> if the attached piece can be rotated, else <code>aligned</code>.
 +
|-
 +
| Selection priority
 +
| {{Type|VarInt}}
 +
|
 +
|-
 +
| Placement priority
 +
| {{Type|VarInt}}
 +
|
 +
|}
  
=== 2012-01-12 ===
+
[[Category:Minecraft Modern]]
* 1.1
 
* Protocol version is now 23
 
* New packet: [[Protocol#Plugin_message_.280xFA.29|0xFA Plugin message]]
 
* [[#Login_Request_.280x01.29|0x01 login request]] has a new string field: level-type (DEFAULT or SUPERFLAT)
 
* [[#Respawn_.280x09.29|0x09 respawn]] has the same change
 
* Packet removed: 0x1B stance update (had been unused for some time)
 
  
=== 2011-11-13 ===
 
* 1.0rc2
 
* Protocol version is not changed
 
* Client gives invalid server key when authentication hash is 8 bytes and the first byte is > 0x80
 
* Bow has extra metadata as slot item.
 
  
=== 2011-11-11 ===
+
==== Program Structure Block ====
* Beta 1.9 pre6.
 
* Protocol version is now 22
 
* NewState: Reason 4 = Enter scrolling text mode after slaying the dragon.
 
* New entity: EnderCrystal (Spawned using the [[Protocol#Add_Object.2FVehicle_.280x17.29|Add Object/Vehicle (0x17)]] packet with type 51)
 
  
=== 2011-10-27 ===
+
{| class="wikitable"
* Beta 1.9 pre5.
+
! Packet ID
* Protocol version is now 21
+
! State
* Packet 0x6B (Create Inventory) changed: uses Slot datatype.
+
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="17"| 0x31
 +
| rowspan="17"| Play
 +
| rowspan="17"| Server
 +
|-
 +
| Location
 +
| {{Type|Position}}
 +
| Block entity location.
 +
|-
 +
| Action
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| An additional action to perform beyond simply saving the given data; see below.
 +
|-
 +
| Mode
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| One of SAVE (0), LOAD (1), CORNER (2), DATA (3).
 +
|-
 +
| Name
 +
| {{Type|String}} (32767)
 +
|
 +
|-
 +
| Offset X || {{Type|Byte}}
 +
| Between -48 and 48.
 +
|-
 +
| Offset Y || {{Type|Byte}}
 +
| Between -48 and 48.
 +
|-
 +
| Offset Z || {{Type|Byte}}
 +
| Between -48 and 48.
 +
|-
 +
| Size X || {{Type|Byte}}
 +
| Between 0 and 48.
 +
|-
 +
| Size Y || {{Type|Byte}}
 +
| Between 0 and 48.
 +
|-
 +
| Size Z || {{Type|Byte}}
 +
| Between 0 and 48.
 +
|-
 +
| Mirror
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| One of NONE (0), LEFT_RIGHT (1), FRONT_BACK (2).
 +
|-
 +
| Rotation
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| One of NONE (0), CLOCKWISE_90 (1), CLOCKWISE_180 (2), COUNTERCLOCKWISE_90 (3).
 +
|-
 +
| Metadata
 +
| {{Type|String}} (128)
 +
|
 +
|-
 +
| Integrity
 +
| {{Type|Float}}
 +
| Between 0 and 1.
 +
|-
 +
|Seed
 +
|{{Type|VarLong}}
 +
|
 +
|-
 +
| Flags
 +
| {{Type|Byte}}
 +
| 0x01: Ignore entities; 0x02: Show air; 0x04: Show bounding box.
 +
|}
  
=== 2011-10-13 ===
+
Possible actions:
* <div class="li">Beta 1.9 pre4.</div>
 
* Protocol version is now 20
 
* Packet 0x2B ([[#Experience_.280x2B.29|Experience]]) changed: now (float, short, short)
 
* New packet 0x6C ([[#Enchant_Item_.280x6C.29|Enchant item]]) added: (byte, byte)
 
* Flint and steel no longer enchantable (see 1.9pre3 changes). Might be others, too.
 
* Notchian server now features an [[Rcon|RCON]] server (server class: o.java)
 
* Notchian server now features "G4S" server [http://pear.php.net/package/Net_GameServerQuery]
 
  
=== 2011-9-29 ===
+
* 0 - Update data
* <div class="li">Beta 1.9 pre2.</div>
+
* 1 - Save the structure
* Protocol version is now 19
+
* 2 - Load the structure
* Four packets changed:
+
* 3 - Detect size
** [[Protocol#Player_Block_Placement_.280x0F.29|0x0F player block placement]]
 
** [[Protocol#Window_click_.280x66.29|0x66 window click]]
 
** [[Protocol#Set_slot_.280x67.29|0x67 set slot]]
 
** [[Protocol#Window_items_.280x68.29|0x68 window items]]
 
* The change affects the "slot" datatype. This type consists of at least a short (item_id). If this id isn't <code>-1</code>, a byte (count) and a short (uses) follow.
 
* From 1.9pre2 onward, additional data is sent but only for [https://gist.github.com/1268479 certain item_ids]. This means the protocol is no longer context free. The additional data is ''at least'' a short. If this short isn't -1, a byte[] array follows, containing ''gzipped'' NBT data
 
* The format of the NBT is as follows
 
<code>
 
  COMPOUND
 
    LIST: 'ench'
 
      SHORT: 'id'
 
      SHORT: 'lvl'
 
    END
 
  END
 
</code>
 
* So far only this format, with 'id' and 'lvl' set to <code>2</code> and <code>1</code> respectively, has been seen.
 
  
=== 2011-9-22 ===
+
The Notchian client uses update data to indicate no special action should be taken (i.e. the done button).
* <div class="li">Beta 1.9 pre1.</div>
 
* Protocol version is now 18
 
  
=== 2011-9-14 ===
+
==== Update Sign ====
* <div class="li">Beta 1.8 release.</div>
 
* Protocol version is now 17
 
  
=== 2011-9-13 ===
+
This message is sent from the client to the server when the “Done” button is pushed after placing a sign.
* <div class="li">Beta 1.8 pre2-release.</div>
 
* Protocol version is now 16
 
* Packet 0x01 ([[#Login_Request_.280x01.29|Login]]) changed (added byte, world height now unsigned)
 
* Packet 0x09 ([[#Respawn_.280x09.29|Respawn]]) changed (added byte)
 
* Packet 0x64 ([[#Open_window_.280x64.29|Open Window]]) changed (Window title changed from string8 to string16)
 
* New packet 0x1a ([[#Experience_Orb_.280x1A.29|Experience Orb]]) added
 
* Assumedly 0x17 ([[#Add_Object.2FVehicle_.280x17.29|Add Object/Vehicle]]) is no longer used for exp orbs.
 
  
=== 2011-9-10 ===
+
The server only accepts this packet after [[#Open Sign Editor|Open Sign Editor]], otherwise this packet is silently ignored.
* <div class="li">Beta 1.8 pre-release.</div>
 
* Protocol version is now 15
 
* Packet 0x00 ([[#Keep_Alive_.280x00.29|Keep Alive]]) changed (added keep-alive id)
 
* Packet 0x01 ([[#Login_Request_.280x01.29|Login]]) changed (added server mode, height limit, and an unknown field)
 
* Packet 0x08 ([[#Update_Health_.280x08.29|Health]]) changed (added food bar and food saturation)
 
* Packet 0x09 ([[#Respawn_.280x09.29|Respawn]]) changed (added map seed, server mode, height limit)
 
* Packet 0x13 ([[#Entity_Action_.280x13.29|Entity Action]]) has new values for starting/stopping sprinting.
 
* Packet 0x46 ([[#New.2FInvalid_State_.280x46.29|New/invalid state]]) changed (added game mode reason, and a game mode byte)
 
* New packet 0x29 ([[#Entity_Effect_.280x29.29|Entity Effect]]) added
 
* New packet 0x2a ([[#Remove_Entity_Effect_.280x2A.29|Remove Entity Effect]]) added
 
* New packet 0x2b ([[#Experience_.280x2B.29|Experience update]]) added
 
* New packet 0x6b ([[#Creative_inventory_action_.280x6B.29|Creative item get]]) added
 
* New packet 0xc9 ([[#Player_List_Item_.280xC9.29|Player list item]]) added
 
* New packet 0xfe ([[#Server_List_Ping_.280xFE.29|Server list ping]]) added
 
* New values for 0x13 ([[#Entity_Action_.280x13.29|Entity Action]]): start sprinting, stop sprinting
 
* New value for 0x17 ([[#Add_Object.2FVehicle_.280x17.29|Add Object/Vehicle]]): experience orb
 
  
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="6"| 0x32
 +
| rowspan="6"| Play
 +
| rowspan="6"| Server
 +
| Location
 +
| {{Type|Position}}
 +
| Block Coordinates.
 +
|-
 +
| Is Front Text
 +
| {{Type|Boolean}}
 +
| Whether the updated text is in front or on the back of the sign
 +
|-
 +
| Line 1
 +
| {{Type|String}} (384)
 +
| First line of text in the sign.
 +
|-
 +
| Line 2
 +
| {{Type|String}} (384)
 +
| Second line of text in the sign.
 +
|-
 +
| Line 3
 +
| {{Type|String}} (384)
 +
| Third line of text in the sign.
 +
|-
 +
| Line 4
 +
| {{Type|String}} (384)
 +
| Fourth line of text in the sign.
 +
|}
  
=== 2011-6-30 ===
+
==== Swing Arm ====
* <div class="li">Beta 1.7 released.</div>
 
* Protocol version number is now 14
 
* No new packets
 
* Packet 0x36 ([[#Block_Action_.280x36.29|Block Action]]) is now used for pistons too.
 
  
=== 2011-5-26 ===
+
Sent when the player's arm swings.
* <div class="li">Beta 1.6 released.</div>
 
* Protocol increase by 2: 13
 
* Packet 0x09 ([[#Respawn_.280x09.29|Respawn]]) changed (added world byte)
 
* Packet 0x17 ([[#Add_Object.2FVehicle_.280x17.29|Add Object]]) changed.
 
* Packet 0x3d ([[#Sound_effect_.280x3D.29|Sound effect]]) added
 
* Packet 0x83 ([[#Map_Data_.280x83.29|Map Data]]) added
 
  
=== 2011-4-19 ===
+
{| class="wikitable"
* <div class="li">Beta 1.5 released.</div>
+
! Packet ID
* Some packet info at https://gist.github.com/929803
+
! State
* Packet 0x01 ([[#Login_Request_.280x01.29|Login Request]]) changed (removed second string)
+
! Bound To
* Packet 0x66 (Window Click) changed (added bool for shift)
+
! Field Name
* Added two new packets: 0x47 ([[#Thunderbolt_.280x47.29|Thunderbolt]]) and 0xC8 ([[#Increment_Statistic_.280xC8.29|Increment Statistic]]) (classes eq and nj, respectively)
+
! Field Type
* Protocol version number is now 11
+
! Notes
* All of the strings are now UCS-2, except for Open window (0x64), which is still UTF-8
+
|-
 +
| 0x33
 +
| Play
 +
| Server
 +
| Hand
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| Hand used for the animation. 0: main hand, 1: off hand.
 +
|}
  
=== 2011-3-31 ===
+
==== Teleport To Entity ====
* <div class="li">Beta 1.4 released.</div>
 
* New packet 0x46.
 
* Protocol version number is now 10
 
* '''TODO:''' The protocol itself does not seem to have changed much, but what about possible data values and stuff like that?
 
  
=== 2011-2-22 ===
+
Teleports the player to the given entity. The player must be in spectator mode.
* <div class="li">Beta 1.3 released.</div>
 
* New packets 0x11, 0x1B: Some information at https://gist.github.com/841590
 
* Protocol number is now 9 (updated)
 
  
=== 2011-1-13 ===
+
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.
* <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>
+
! Packet ID
* A whole host of packet changes. 0x05, 0x08, 0x10, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, and 0x82. Packets 0x11 and 0x3b removed.
+
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
| 0x34
 +
| Play
 +
| Server
 +
| Target Player
 +
| {{Type|UUID}}
 +
| UUID of the player to teleport to (can also be an entity UUID).
 +
|}
  
=== 2010-12-01 ===
+
==== Use Item On ====
* <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 ===
+
{| class="wikitable"
* <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>
+
! Packet ID
* <div class="li"> Packet 0x08 ([[#Update Health (0x08)|Update Health]]) added</div>
+
! State
* <div class="li"> Packet 0x09 ([[#Respawn (0x09)|Respawn]]) added</div>
+
! Bound To
* <div class="li"> Packet 0x12 ([[#Animation_.280x12.29|Animation]]) started getting non-boolean values for the Animation field</div>
+
! Field Name
* <div class="li"> Packet 0x26 (Entity Death) added</div>
+
! Field Type
 +
! Notes
 +
|-
 +
| rowspan="8"| 0x35
 +
| rowspan="8"| Play
 +
| rowspan="8"| Server
 +
| Hand
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| The hand from which the block is placed; 0: main hand, 1: off hand.
 +
|-
 +
| Location
 +
| {{Type|Position}}
 +
| Block position.
 +
|-
 +
| Face
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| The face on which the block is placed (as documented at [[#Player Action|Player Action]]).
 +
|-
 +
| Cursor Position X
 +
| {{Type|Float}}
 +
| The position of the crosshair on the block, from 0 to 1 increasing from west to east.
 +
|-
 +
| Cursor Position Y
 +
| {{Type|Float}}
 +
| The position of the crosshair on the block, from 0 to 1 increasing from bottom to top.
 +
|-
 +
| Cursor Position Z
 +
| {{Type|Float}}
 +
| The position of the crosshair on the block, from 0 to 1 increasing from north to south.
 +
|-
 +
| Inside block
 +
| {{Type|Boolean}}
 +
| True when the player's head is inside of a block.
 +
|-
 +
| Sequence
 +
| {{Type|VarInt}}
 +
| Block change sequence number (see [[#Acknowledge Block Change]]).
 +
|}
 +
 
 +
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.
  
=== 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
 +
|-
 +
| rowspan="2"| 0x36
 +
| rowspan="2"| Play
 +
| rowspan="2"| Server
 +
| Hand
 +
| {{Type|VarInt}} {{Type|Enum}}
 +
| Hand used for the animation. 0: main hand, 1: off hand.
 +
|-
 +
| Sequence
 +
| {{Type|VarInt}}
 +
| Block change sequence number (see [[#Acknowledge Block Change]]).
 +
|}
  
 
[[Category:Protocol Details]]
 
[[Category:Protocol Details]]
[[Category:Minecraft Beta]]
+
[[Category:Minecraft Modern]]

Latest revision as of 07:25, 20 March 2024

Heads up!

This article is about the protocol for the latest stable release of Minecraft Java Edition (1.20.4, protocol 765). 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 irc.libera.chat (More Information).

Note: While you may use the contents of this page without restriction to create servers, clients, bots, etc; substantial reproductions of this page must be attributed IAW CC BY-SA 4.0.

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”.
Registry A table describing static, gameplay-related objects of some kind, such as the types of entities, block states or biomes. The entries of a registry are typically associated with textual or numeric identifiers, or both.

Minecraft has a unified registry system used to implement most of the registries, including blocks, items, entities, biomes and dimensions. These "ordinary" registries associate entries with both namespaced textual identifiers (see #Identifier), and signed (positive) 32-bit numeric identifiers. There is also a registry of registries listing all of the registries in the registry system. Some other registries, most notably the block state registry, are however implemented in a more ad-hoc fashion.

Some registries, such as biomes and dimensions, can be customized at runtime by the server (see Registry Data), while others, such as blocks, items and entities, are hardcoded. The contents of the hardcoded registries can be extracted via the built-in Data Generators system.

Block state Each block in Minecraft has 0 or more properties, which in turn may have any number of possible values. These represent, for example, the orientations of blocks, poweredness states of redstone components, and so on. Each of the possible permutations of property values for a block is a distinct block state. The block state registry assigns a numeric identifier to every block state of every block.

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.
Sequence The action number counter for local block changes, incremented by one when clicking a block with a hand, right clicking an item, or starting or finishing digging a block. Counter handles latency to avoid applying outdated block changes to the local world. Also is used to revert ghost blocks created when placing blocks, using buckets, or breaking blocks.

Packet format

Packets cannot be larger than 221 − 1 or 2097151 bytes (the maximum that can be sent in a 3-byte VarInt). Moreover, the length field must not be longer than 3 bytes, even if the encoded value is within the limit. Unnecessarily long encodings at 3 bytes or below are still allowed. For compressed packets, this applies to the Packet Length field, i.e. the compressed length.

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 slightly 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)

For serverbound packets, the uncompressed length of (Packet ID + Data) must not be greater than 223 or 8388608 bytes. Not that a length equal to 223 is permitted, which differs from the compressed length limit. The Notchian client, on the other hand, has no limit for the uncompressed length of incoming compressed packets.

If the size of the buffer containing the packet data and ID (as a VarInt) is smaller than the threshold specified in the packet Set Compression. It will be sent as uncompressed. This is done by setting the data length as 0. (Comparable to sending a non-compressed format with an extra 0 between the length, and packet data).

If it's larger than or equal to the threshold, then it follows the regular compressed protocol format.

The Notchian server (but not client) rejects compressed packets smaller than the threshold. Uncompressed packets exceeding the threshold, however, are accepted.

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 765 in Minecraft 1.20.4).
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 simple redirect, e.g. if _minecraft._tcp.example.com points to mc.example.org, users connecting to example.com will provide 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. The format of this packet is a remnant of the pre-Netty age, before the switch to Netty in 1.7 brought the standard format that is recognized now. This packet merely exists to inform legacy clients that they can't join our modern server.

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

Status Response

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

Ping Response (status)

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

Status Request

The status can only be requested once immediately after the handshake, before any ping. The server won't respond otherwise.

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

Ping Request (status)

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
  9. C→S: Login Acknowledged

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 integrated servers (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. The Notchian server uses UUID v3 for offline player UUIDs, with the namespace “OfflinePlayer” and the value as the player’s username. For example, Notch’s offline UUID would be derived from the string “OfflinePlayer:Notch”. This is not a requirement however, the UUID may be anything.

See Protocol Encryption for details.

Clientbound

Disconnect (login)

Packet ID State Bound To Field Name Field Type Notes
0x00 Login Client Reason JSON Text Component The reason why the player was disconnected.

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 The server's public key, in bytes.
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 UUID
Username 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.

The properties included in this packet are the same as in Player Info Update, for the current player.

Set Compression

Enables compression. If compression is enabled, all following packets are encoded in the compressed packet format. Negative 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 (1048576) Any data, depending on the channel. The length of this array must be inferred from the packet length.

In Notchian client, the maximum data length is 1048576 bytes.

Serverbound

Login Start

Packet ID State Bound To Field Name Field Type Notes
0x00 Login Server Name String (16) Player's Username.
Player UUID UUID The UUID of the player logging in. Unused by the Notchian server.

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 Shared Secret value, encrypted with the server's public key.
Verify Token Length VarInt Length of Verify Token.
Verify Token Byte Array Verify Token value, encrypted with the same public key as the shared secret.

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 understood the request, false otherwise. When false, no payload follows.
Data Optional Byte Array (1048576) Any data, depending on the channel. The length of this array must be inferred from the packet length.

In Notchian server, the maximum data length is 1048576 bytes.

Login Acknowledged

Acknowledgement to the Login Success packet sent by the server.

Packet ID State Bound To Field Name Field Type Notes
0x03 Login Server no fields

This packet switches the connection state to configuration.

Configuration

Clientbound

Clientbound Plugin Message (configuration)

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 information on how it works on Dinnerbone's blog. More documentation about internal and popular registered channels are here.

Packet ID State Bound To Field Name Field Type Notes
0x00 Configuration Client Channel Identifier Name of the plugin channel used to send the data.
Data Byte Array (1048576) Any data. The length of this array must be inferred from the packet length.

In Notchian client, the maximum data length is 1048576 bytes.

Disconnect (configuration)

Packet ID State Bound To Field Name Field Type Notes
0x01 Configuration Client Reason Text Component The reason why the player was disconnected.

Finish Configuration

Sent by the server to notify the client that the configuration process has finished. The client answers with Acknowledge Finish Configuration whenever it is ready to continue.

Packet ID State Bound To Field Name Field Type Notes
0x02 Configuration Client no fields

This packet switches the connection state to play.

Clientbound Keep Alive (configuration)

The server will frequently send out a keep-alive, each containing a random ID. The client must respond with the same payload (see Serverbound Keep Alive). 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
0x03 Configuration Client Keep Alive ID Long

Ping (configuration)

Packet is not used by the Notchian server. When sent to the client, client responds with a Pong packet with the same id.

Packet ID State Bound To Field Name Field Type Notes
0x04 Configuration Client ID Int

Registry Data

Represents certain registries that are sent from the server and are applied on the client.

Packet ID State Bound To Field Name Field Type Notes
0x05 Configuration Client Registry Codec NBT (Compound) See Registry Data.

Remove Resource Pack (configuration)

Packet ID State Bound To Field Name Field Type Notes
0x06 Configuration Client Has UUID Boolean Whether a specific resource pack should be removed, or all of them.
UUID Optional UUID The UUID of the resource pack to be removed. Only present if the previous field is true.

Add Resource Pack (configuration)

Packet ID State Bound To Field Name Field Type Notes
0x07 Configuration Client UUID UUID The unique identifier of the resource pack.
URL String (32767) The URL to the resource pack.
Hash String (40) A 40 character hexadecimal, case-insensitive SHA-1 hash of the resource pack file.
If it's not a 40 character hexadecimal string, the client will not use it for hash verification and likely waste bandwidth.
Forced Boolean The Notchian client will be forced to use the resource pack from the server. If they decline they will be kicked from the server.
Has Prompt Message Boolean Whether a custom message should be used on the resource pack prompt.
Prompt Message Optional Text Component This is shown in the prompt making the client accept or decline the resource pack. Only present if the previous field is true.

Feature Flags

Used to enable and disable features, generally experimental ones, on the client.

Packet ID State Bound To Field Name Field Type Notes
0x08 Configuration Client Total Features VarInt Number of features that appear in the array below.
Feature Flags Identifier

As of 1.20.4, the following feature flags are available:

  • minecraft:vanilla - enables vanilla features
  • minecraft:bundle - enables support for the bundle
  • minecraft:trade_rebalance - enables support for the rebalanced villager trades
  • minecraft:update_1_21 - enables support for 1.21 features

Update Tags (configuration)

Packet ID State Bound To Field Name Field Type Notes
0x09 Configuration Client Length of the array VarInt
Array of tags Registry Array Identifier Registry identifier (Vanilla expects tags for the registries minecraft:block, minecraft:item, minecraft:fluid, minecraft:entity_type, and minecraft:game_event)
Array of Tag (See below)

Tag arrays 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 IDs of the given type (block, item, etc.). This list replaces the previous list of IDs for the given tag. If some preexisting tags are left unmentioned, a warning is printed.

See Tag on the Minecraft Wiki for more information, including a list of vanilla tags.

Serverbound

Client Information (configuration)

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

Packet ID State Bound To Field Name Field Type Notes
0x00 Configuration 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 Chat#Client chat mode for more information.
Chat Colors Boolean “Colors” multiplayer setting. Can the chat be colored?
Displayed Skin Parts Unsigned Byte Bit mask, see below.
Main Hand VarInt Enum 0: Left, 1: Right.
Enable text filtering Boolean Enables filtering of text on signs and written book titles. Currently always false (i.e. the filtering is disabled)
Allow server listings Boolean Servers usually list online players, this option should let you not show up in that list.

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.

Serverbound Plugin Message (configuration)

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: https://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
0x01 Configuration Server Channel Identifier Name of the plugin channel used to send the data.
Data Byte Array (32767) Any data, depending on the channel. minecraft: channels are documented here. The length of this array must be inferred from the packet length.

In Notchian server, the maximum data length is 32767 bytes.

Acknowledge Finish Configuration

Sent by the client to notify the client that the configuration process has finished. It is sent in response to the server's Finish Configuration.

Packet ID State Bound To Field Name Field Type Notes
0x02 Configuration Server no fields

This packet switches the connection state to play.

Serverbound Keep Alive (configuration)

The server will frequently send out a keep-alive (see Clientbound 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
0x03 Configuration Server Keep Alive ID Long

Pong (configuration)

Response to the clientbound packet (Ping) with the same id.

Packet ID State Bound To Field Name Field Type Notes
0x04 Configuration Server ID Int id is the same as the ping packet

Resource Pack Response (configuration)

Packet ID State Bound To Field Name Field Type Notes
0x05 Configuration Server
UUID UUID The unique identifier of the resource pack received in the Add Resource Pack (configuration) request.
Result VarInt Enum Result ID (see below).

Result can be one of the following values:

ID Result
0 Successfully downloaded
1 Declined
2 Failed to download
3 Accepted
4 Downloaded
5 Invalid URL
6 Failed to reload
7 Discarded

Play

Clientbound

Bundle Delimiter

The delimiter for a bundle of packets. When received, the client should store every subsequent packet it receives, and wait until another delimiter is received. Once that happens, the client is guaranteed to process every packet in the bundle on the same tick, and the client should stop storing packets. For example, this is used to ensure Spawn Entity and Set Entity Metadata happen on the same tick.

The Notchian client doesn't allow more than 4096 packets in the same bundle.

Packet ID State Bound To Field Name Field Type Notes
0x00 Play Client no fields

Spawn Entity

Sent by the server when an entity (aside from Experince Orb) is created.

Packet ID State Bound To Field Name Field Type Notes
0x01 Play Client Entity ID VarInt A unique integer ID mostly used in the protocol to identify the entity.
Entity UUID UUID A unique identifier that is mostly used in persistence and places where the uniqueness matters more.
Type VarInt ID in the minecraft:entity_type registry (see "type" field in Entity metadata#Entities).
X Double
Y Double
Z Double
Pitch Angle To get the real pitch, you must divide this by (256.0F / 360.0F)
Yaw Angle To get the real yaw, you must divide this by (256.0F / 360.0F)
Head Yaw Angle Only used by living entities, where the head of the entity may differ from the general body rotation.
Data VarInt Meaning dependent on the value of the Type field, see Object Data for details.
Velocity X Short Same units as Set Entity Velocity.
Velocity Y Short
Velocity Z Short

Warning.png The points listed below should be considered when this packet is used to spawn a player entity.

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). The Notchian server uses UUID.nameUUIDFromBytes, implemented by OpenJDK here.

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.

Spawn Experience Orb

Spawns one or more experience orbs.

Packet ID State Bound To Field Name Field Type Notes
0x02 Play Client Entity ID VarInt
X Double
Y Double
Z Double
Count Short The amount of experience this orb will reward once collected.

Entity Animation

Sent whenever an entity should change animation.

Packet ID State Bound To Field Name Field Type Notes
0x03 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
2 Leave bed
3 Swing offhand
4 Critical effect
5 Magic critical effect

Award Statistics

Sent as a response to Client Command (id 1). Will only send the changed values if previously requested.

Packet ID State Bound To Field Name Field Type Notes
0x04 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.time_since_rest 3 Time
minecraft.sneak_time 4 Time
minecraft.walk_one_cm 5 Distance
minecraft.crouch_one_cm 6 Distance
minecraft.sprint_one_cm 7 Distance
minecraft.walk_on_water_one_cm 8 Distance
minecraft.fall_one_cm 9 Distance
minecraft.climb_one_cm 10 Distance
minecraft.fly_one_cm 11 Distance
minecraft.walk_under_water_one_cm 12 Distance
minecraft.minecart_one_cm 13 Distance
minecraft.boat_one_cm 14 Distance
minecraft.pig_one_cm 15 Distance
minecraft.horse_one_cm 16 Distance
minecraft.aviate_one_cm 17 Distance
minecraft.swim_one_cm 18 Distance
minecraft.strider_one_cm 19 Distance
minecraft.jump 20 None
minecraft.drop 21 None
minecraft.damage_dealt 22 Damage
minecraft.damage_dealt_absorbed 23 Damage
minecraft.damage_dealt_resisted 24 Damage
minecraft.damage_taken 25 Damage
minecraft.damage_blocked_by_shield 26 Damage
minecraft.damage_absorbed 27 Damage
minecraft.damage_resisted 28 Damage
minecraft.deaths 29 None
minecraft.mob_kills 30 None
minecraft.animals_bred 31 None
minecraft.player_kills 32 None
minecraft.fish_caught 33 None
minecraft.talked_to_villager 34 None
minecraft.traded_with_villager 35 None
minecraft.eat_cake_slice 36 None
minecraft.fill_cauldron 37 None
minecraft.use_cauldron 38 None
minecraft.clean_armor 39 None
minecraft.clean_banner 40 None
minecraft.clean_shulker_box 41 None
minecraft.interact_with_brewingstand 42 None
minecraft.interact_with_beacon 43 None
minecraft.inspect_dropper 44 None
minecraft.inspect_hopper 45 None
minecraft.inspect_dispenser 46 None
minecraft.play_noteblock 47 None
minecraft.tune_noteblock 48 None
minecraft.pot_flower 49 None
minecraft.trigger_trapped_chest 50 None
minecraft.open_enderchest 51 None
minecraft.enchant_item 52 None
minecraft.play_record 53 None
minecraft.interact_with_furnace 54 None
minecraft.interact_with_crafting_table 55 None
minecraft.open_chest 56 None
minecraft.sleep_in_bed 57 None
minecraft.open_shulker_box 58 None
minecraft.open_barrel 59 None
minecraft.interact_with_blast_furnace 60 None
minecraft.interact_with_smoker 61 None
minecraft.interact_with_lectern 62 None
minecraft.interact_with_campfire 63 None
minecraft.interact_with_cartography_table 64 None
minecraft.interact_with_loom 65 None
minecraft.interact_with_stonecutter 66 None
minecraft.bell_ring 67 None
minecraft.raid_trigger 68 None
minecraft.raid_win 69 None
minecraft.interact_with_anvil 70 None
minecraft.interact_with_grindstone 71 None
minecraft.target_hit 72 None
minecraft.interact_with_smithing_table 73 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 Block Change

Acknowledges a user-initiated block change. After receiving this packet, the client will display the block state sent by the server instead of the one predicted by the client.

Packet ID State Bound To Field Name Field Type Notes
0x05 Play Client Sequence ID VarInt Represents the sequence to acknowledge, this is used for properly syncing block changes to the client after interactions.

Set Block Destroy Stage

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
0x06 Play Client Entity ID VarInt The 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
0x07 Play Client Location Position
Type VarInt The type of the block entity
NBT Data NBT 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).

Block Action

This packet is used for a number of actions and animations performed by blocks, usually non-persistent. The client ignores the provided block type and instead uses the block state in their world.

See Block Actions for a list of values.

Warning.png This packet uses a block ID from the minecraft:block registry, not a block state.

Packet ID State Bound To Field Name Field Type Notes
0x08 Play Client Location Position Block coordinates.
Action ID (Byte 1) Unsigned Byte Varies depending on block — see Block Actions.
Action Parameter (Byte 2) Unsigned Byte Varies depending on block — see Block Actions.
Block Type VarInt The block type ID for the block. This value is unused by the Notchian client, as it will infer the type of block based on the given position.

Block Update

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
0x09 Play Client Location Position Block Coordinates.
Block ID VarInt The new block state ID for the block as given in the block state registry.

Boss Bar

Packet ID State Bound To Field Name Field Type Notes
0x0A 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 Text Component
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 Text Component
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

Change Difficulty

Changes the difficulty setting in the client's option menu

Packet ID State Bound To Field Name Field Type Notes
0x0B Play Client Difficulty Unsigned Byte 0: peaceful, 1: easy, 2: normal, 3: hard.
Difficulty locked? Boolean

Chunk Batch Finished

Marks the end of a chunk batch. The Notchian client marks the time it receives this packet and calculates the elapsed duration since the beginning of the chunk batch. The server uses this duration and the batch size received in this packet to estimate the number of milliseconds elapsed per chunk received. This value is then used to calculate the desired number of chunks per tick through the formula 25 / millisPerChunk, which is reported to the server through Chunk Batch Received. This likely uses 25 instead of the normal tick duration of 50 so chunk processing will only use half of the client's and network's bandwidth.

The Notchian client uses the samples from the latest 15 batches to estimate the milliseconds per chunk number.

Packet ID State Bound To Field Name Field Type Notes
0x0C Play Client Batch size VarInt Number of chunks.

Chunk Batch Start

Marks the start of a chunk batch. The Notchian client marks and stores the time it receives this packet.

Packet ID State Bound To Field Name Field Type Notes
0x0D Play Client no fields

Chunk Biomes

Packet ID State Bound To Field Name Field Type Notes
0x0E Play Client
Number of chunks VarInt Number of elements in the following array
Chunk biome data Chunk Z Array Int Chunk coordinate (block coordinate divided by 16, rounded down)
Chunk X Int Chunk coordinate (block coordinate divided by 16, rounded down)
Size VarInt Size of Data in bytes
Data Byte Array Chunk data structure, with sections containing only the Biomes field

Note: The order of X and Z is inverted, because the client reads them as one big-endian Long, with Z being the upper 32 bits.

Clear Titles

Clear the client's current title information, with the option to also reset it.

Packet ID State Bound To Field Name Field Type Notes
0x0F Play Client Reset Boolean

Command Suggestions Response

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
0x10 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 Text Component Tooltip to display; only present if previous boolean is true.

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
0x11 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.

Close Container

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. The notchian client disregards the provided window ID and closes any active window.

Packet ID State Bound To Field Name Field Type Notes
0x12 Play Client Window ID Unsigned Byte This is the ID of the window that was closed. 0 for inventory.

Set Container Content

The inventory slots

Replaces the contents of a container window. Sent by the server upon initialization of a container window or the player's inventory, and in response to state ID mismatches (see #Click Container).

Packet ID State Bound To Field Name Field Type Notes
0x13 Play Client Window ID Unsigned Byte The ID of window which items are being sent for. 0 for player inventory. The client ignores any packets targeting a Window ID other than the current one. However, an exception is made for the player inventory, which may be targeted at any time. (The Notchian server does not appear to utilize this special case.)
State ID VarInt A server-managed sequence number used to avoid desynchronization; see #Click Container.
Count VarInt Number of elements in the following array.
Slot Data Array of Slot
Carried Item Slot Item being dragged with the mouse.

See inventory windows for further information about how slots are indexed. Use Open Screen to open the container on the client.

Set Container 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
0x14 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
Stonecutter 0: Selected recipe The index of the selected recipe. -1 means none is selected.
Loom 0: Selected pattern The index of the selected pattern. 0 means none is selected, 0 is also the internal id of the "base" pattern.
Lectern 0: Page number The current page number, starting from 0.

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:soul_speed Soul Speed
12 minecraft:sharpness Sharpness
13 minecraft:smite Smite
14 minecraft:bane_of_arthropods Bane of Arthropods
15 minecraft:knockback Knockback
16 minecraft:fire_aspect Fire Aspect
17 minecraft:looting Looting
18 minecraft:sweeping Sweeping Edge
19 minecraft:efficiency Efficiency
20 minecraft:silk_touch Silk Touch
21 minecraft:unbreaking Unbreaking
22 minecraft:fortune Fortune
23 minecraft:power Power
24 minecraft:punch Punch
25 minecraft:flame Flame
26 minecraft:infinity Infinity
27 minecraft:luck_of_the_sea Luck of the Sea
28 minecraft:lure Lure
29 minecraft:loyalty Loyalty
30 minecraft:impaling Impaling
31 minecraft:riptide Riptide
32 minecraft:channeling Channeling
33 minecraft:multishot Multishot
34 minecraft:quick_charge Quick Charge
35 minecraft:piercing Piercing
36 minecraft:mending Mending
37 minecraft:vanishing_curse Curse of Vanishing

Set Container 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
0x15 Play Client Window ID Byte The window which is being updated. 0 for player inventory. The client ignores any packets targeting a Window ID other than the current one; see below for exceptions.
State ID VarInt A server-managed sequence number used to avoid desynchronization; see #Click Container.
Slot Short The slot that should be updated.
Slot Data Slot

If Window ID is 0, the hotbar and offhand slots (slots 36 through 45) may be updated even when a different container window is open. (The Notchian server does not appear to utilize this special case.) Updates are also restricted to those slots when the player is looking at a creative inventory tab other than the survival inventory. (The Notchian server does not handle this restriction in any way, leading to MC-242392.)

If Window ID is -1, the item being dragged with the mouse is set. In this case, State ID and Slot are ignored.

If Window ID is -2, any slot in the player's inventory can be updated irrespective of the current container window. In this case, State ID is ignored, and the Notchian server uses a bogus value of 0. Used by the Notchian server to implement the #Pick Item functionality.

When a container window is open, the server never sends updates targeting Window ID 0—all of the window types include slots for the player inventory. The client must automatically apply changes targeting the inventory portion of a container window to the main inventory; the server does not resend them for ID 0 when the window is closed. However, since the armor and offhand slots are only present on ID 0, updates to those slots occurring while a window is open must be deferred by the server until the window's closure.

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
0x16 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.

Chat Suggestions

Unused by the Notchian server. Likely provided for custom servers to send chat message completions to clients.

Packet ID State Bound To Field Name Field Type Notes
0x17 Play Client Action VarInt Enum 0: Add, 1: Remove, 2: Set
Count VarInt Number of elements in the following array.
Entries Array of String (32767)

Clientbound Plugin Message (play)

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 information on how it works on Dinnerbone's blog. More documentation about internal and popular registered channels are here.

Packet ID State Bound To Field Name Field Type Notes
0x18 Play Client Channel Identifier Name of the plugin channel used to send the data.
Data Byte Array (1048576) Any data. The length of this array must be inferred from the packet length.

In Notchian client, the maximum data length is 1048576 bytes.

Damage Event

Packet ID State Bound To Field Name Field Type Notes
0x19 Play Client
Entity ID VarInt The ID of the entity taking damage
Source Type ID VarInt The type of damage in the minecraft:damage_type registry, defined by the Registry Data packet.
Source Cause ID VarInt The ID + 1 of the entity responsible for the damage, if present. If not present, the value is 0
Source Direct ID VarInt The ID + 1 of the entity that directly dealt the damage, if present. If not present, the value is 0. If this field is present:
  • and damage was dealt indirectly, such as by the use of a projectile, this field will contain the ID of such projectile;
  • and damage was dealt dirctly, such as by manually attacking, this field will contain the same value as Source Cause ID.
Has Source Position Boolean Indicates the presence of the three following fields.

The Notchian server sends the Source Position when the damage was dealt by the /damage command and a position was specified

Source Position X Optional Double Only present if Has Source Position is true
Source Position Y Optional Double Only present if Has Source Position is true
Source Position Z Optional Double Only present if Has Source Position is true

Delete Message

Removes a message from the client's chat. This only works for messages with signatures, system messages cannot be deleted with this packet.

Packet ID State Bound To Field Name Field Type Notes
0x1A Play Client Message ID VarInt The message Id + 1, used for validating message signature. The next field is present only when value of this field is equal to 0.
Signature Optional Byte Array (256) The previous message's signature. Always 256 bytes and not length-prefixed.

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 Text Component Displayed to the client when the connection terminates.

Disguised Chat Message

Sends the client a chat message, but without any message signing information.

The Notchian server uses this packet when the console is communicating with players through commands, such as /say, /tell, /me, among others.

Packet ID State Bound To Field Name Field Type Notes
0x1C Play Client Message Text Component This is used as the content parameter when formatting the message on the client.
Chat Type VarInt The type of chat in the minecraft:chat_type registry, defined by the Registry Data packet.
Sender Name Text Component The name of the one sending the message, usually the sender's display name.

This is used as the sender parameter when formatting the message on the client.

Has Target Name Boolean True if target name is present.
Target Name Text Component The name of the one receiving the message, usually the receiver's display name. Only present if previous boolean is true.

This is used as the target parameter when formatting the message on the client.

Entity Event

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
0x1D Play Client Entity ID Int
Entity Status Byte Enum 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
0x1E Play Client X Double
Y Double
Z Double
Strength Float If the strength is greater or equal to 2.0, or the block interaction is not 0 (keep), large explosion particles are used. Otherwise, small explosion particles are used.
Record Count VarInt 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.
Block Interaction VarInt Enum 0 = keep, 1 = destroy, 2 = destroy_with_decay, 3 = trigger_block.
Small Explosion Particle ID VarInt The particle ID listed in Particles.
Small Explosion Particle Data Varies Particle data as specified in Particles.
Large Explosion Particle ID VarInt The particle ID listed in Particles.
Large Explosion Particle Data Varies Particle data as specified in Particles.
Explosion Sound Sound Name Identifier The name of the sound played.
Has Fixed Range Optional Boolean Whether is has fixed range.
Range Optional Float The fixed range of the sound. Only present if previous boolean is true.

Unload Chunk

Tells the client to unload a chunk column.

Packet ID State Bound To Field Name Field Type Notes
0x1F Play Client Chunk Z Int Block coordinate divided by 16, rounded down.
Chunk X Int Block coordinate divided by 16, rounded down.

Note: The order is inverted, because the client reads this packet as one big-endian Long, with Z being the upper 32 bits.

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

Game Event

Used for a wide variety of game events, from weather to bed use to game mode to demo messages.

Packet ID State Bound To Field Name Field Type Notes
0x20 Play Client Event Unsigned Byte See below.
Value Float Depends on Event.

Events:

Event Effect Value
0 No respawn block available Note: Displays message 'block.minecraft.spawn.not_valid' (You have no home bed or charged respawn anchor, or it was obstructed) to the player.
1 End raining
2 Begin raining
3 Change game mode 0: Survival, 1: Creative, 2: Adventure, 3: Spectator.
4 Win game 0: Just respawn player.
1: Roll the credits and respawn player.
Note that 1 is only sent by notchian server when player has not yet achieved advancement "The end?", else 0 is sent.
5 Demo event 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 hit player Note: Sent when any player is struck by an arrow.
7 Rain level change Note: Seems to change both sky color and lighting.
Rain level ranging from 0 to 1.
8 Thunder level change Note: Seems to change both sky color and lighting (same as Rain level change, but doesn't start rain). It also requires rain to render by notchian client.
Thunder level ranging from 0 to 1.
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).
12 Limited crafting 0: Disable limited crafting.
1: Enable limited crafting (sent when the doLimitedCrafting gamerule changes).
13 Start waiting for level chunks Instructs the client to begin the waiting process for the level chunks.
Sent by the server after the level is cleared on the client and is being re-sent (either during the first, or subsequent reconfigurations).

Open Horse Screen

This packet is used exclusively for opening the horse GUI. Open Screen is used for all other GUIs. The client will not open the inventory if the Entity ID does not point to an horse-like animal.

Packet ID State Bound To Field Name Field Type Notes
0x21 Play Client Window ID Unsigned Byte
Slot count VarInt
Entity ID Int

Hurt Animation

Plays a bobbing animation for the entity receiving damage.

Packet ID State Bound To Field Name Field Type Notes
0x22 Play Client
Entity ID VarInt The ID of the entity taking damage
Yaw Float The direction the damage is coming from in relation to the entity

Initialize World Border

Packet ID State Bound To Field Name Field Type Notes
0x23 Play Client 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 Blocks VarInt In meters.
Warning Time VarInt In seconds as set by /worldborder warning time.

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;
}

Clientbound Keep Alive (play)

The server will frequently send out a keep-alive, each containing a random ID. The client must respond with the same payload (see Serverbound Keep Alive). 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
0x24 Play Client Keep Alive ID Long

Chunk Data and Update Light

Main article: Chunk Format
See also: #Unload Chunk

Sent when a chunk comes into the client's view distance, specifying its terrain, lighting and block entities.

The chunk must be within the view area previously specified with Set Center Chunk; see that packet for details.

It is not strictly necessary to send all block entities in this packet; it is still legal to send them with Block Entity Data later.

Packet ID State Bound To Field Name Field Type Notes
0x25 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)
Heightmaps NBT See Chunk Format#Heightmaps structure
Size VarInt Size of Data in bytes
Data Byte Array See Chunk Format#Data structure
Number of block entities VarInt Number of elements in the following array
Block Entity Packed XZ Array Unsigned Byte The packed section coordinates are relative to the chunk they are in. Values 0-15 are valid.
packed_xz = ((blockX & 15) << 4) | (blockZ & 15) // encode
x = packed_xz >> 4, z = packed_xz & 15 // decode
Y Short The height relative to the world
Type VarInt The type of block entity
Data NBT The block entity's data, without the X, Y, and Z values
Sky Light Mask BitSet BitSet containing bits for each section in the world + 2. Each set bit indicates that the corresponding 16×16×16 chunk section has data in the Sky Light array below. The least significant bit is for blocks 16 blocks to 1 block below the min world height (one section below the world), while the most significant bit covers blocks 1 to 16 blocks above the max world height (one section above the world).
Block Light Mask BitSet BitSet containing bits for each section in the world + 2. Each set bit indicates that the corresponding 16×16×16 chunk section has data in the Block Light array below. The order of bits is the same as in Sky Light Mask.
Empty Sky Light Mask BitSet BitSet containing bits for each section in the world + 2. Each set bit indicates that the corresponding 16×16×16 chunk section has all zeros for its Sky Light data. The order of bits is the same as in Sky Light Mask.
Empty Block Light Mask BitSet BitSet containing bits for each section in the world + 2. Each set bit indicates that the corresponding 16×16×16 chunk section has all zeros for its Block Light data. The order of bits is the same as in Sky Light Mask.
Sky Light array count VarInt Number of entries in the following array; should match the number of bits set in Sky Light Mask
Sky Light arrays Length Array VarInt Length of the following array in bytes (always 2048)
Sky Light array Byte Array (2048) 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. Indexed ((y<<8) | (z<<4) | x) / 2 If there's a remainder, masked 0xF0 else 0x0F.
Block Light array count VarInt Number of entries in the following array; should match the number of bits set in Block Light Mask
Block Light arrays Length Array VarInt Length of the following array in bytes (always 2048)
Block Light array Byte Array (2048) 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. Indexed ((y<<8) | (z<<4) | x) / 2 If there's a remainder, masked 0xF0 else 0x0F.

Unlike the Update Light packet which uses the same format, setting the bit corresponding to a section to 0 in both of the block light or sky light masks does not appear to be useful, and the results in testing have been highly inconsistent.

World Event

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
0x26 Play Client Event Int The event, see below.
Location Position The location of the event.
Data Int Extra data for certain events, see below.
Disable Relative Volume Boolean See above.

Events:

ID Name Data
Sound
1000 Dispenser dispenses
1001 Dispenser fails to dispense
1002 Dispenser shoots
1003 Ender eye launched
1004 Firework shot
1009 Fire extinguished
1010 Play record An ID in the minecraft:item registry, corresponding to a record item. If the ID doesn't correspond to a record, the packet is ignored. Any record already being played at the given location is overwritten. See Data Generators for information on item IDs.
1011 Stop record
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 ID (see Chunk Format#Block state registry).
2002 Splash potion. Particle effect + glass break sound. RGB color as an integer (e.g. 8364543 for #7FA1FF).
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. Particle effect + glass break sound. RGB color as an integer (e.g. 8364543 for #7FA1FF).
2008 Ender dragon destroys block
2009 Wet sponge vaporizes in nether
3000 End gateway spawn
3001 Enderdragon growl
3002 Electric spark
3003 Copper apply wax
3004 Copper remove wax
3005 Copper scrape oxidation

Smoke directions:

ID Direction
0 Down
1 Up
2 North
3 South
4 West
5 East

Particle

Displays the named particle

Packet ID State Bound To Field Name Field Type Notes
0x27 Play Client Particle ID VarInt The particle ID listed in Particles.
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().
Max Speed Float
Particle Count Int The number of particles to create.
Data Varies Particle data as specified in Particles.

Update Light

Updates light levels for a chunk. See Light for information on how lighting works in Minecraft.

Packet ID State Bound To Field Name Field Type Notes
0x28 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 BitSet BitSet containing bits for each section in the world + 2. Each set bit indicates that the corresponding 16×16×16 chunk section has data in the Sky Light array below. The least significant bit is for blocks 16 blocks to 1 block below the min world height (one section below the world), while the most significant bit covers blocks 1 to 16 blocks above the max world height (one section above the world).
Block Light Mask BitSet BitSet containing bits for each section in the world + 2. Each set bit indicates that the corresponding 16×16×16 chunk section has data in the Block Light array below. The order of bits is the same as in Sky Light Mask.
Empty Sky Light Mask BitSet BitSet containing bits for each section in the world + 2. Each set bit indicates that the corresponding 16×16×16 chunk section has all zeros for its Sky Light data. The order of bits is the same as in Sky Light Mask.
Empty Block Light Mask BitSet BitSet containing bits for each section in the world + 2. Each set bit indicates that the corresponding 16×16×16 chunk section has all zeros for its Block Light data. The order of bits is the same as in Sky Light Mask.
Sky Light array count VarInt Number of entries in the following array; should match the number of bits set in Sky Light Mask
Sky Light arrays Length Array VarInt Length of the following array in bytes (always 2048)
Sky Light array Byte Array (2048) 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 array count VarInt Number of entries in the following array; should match the number of bits set in Block Light Mask
Block Light arrays Length Array VarInt Length of the following array in bytes (always 2048)
Block Light array Byte Array (2048) 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.

A bit will never be set in both the block light mask and the empty block light mask, though it may be present in neither of them (if the block light does not need to be updated for the corresponding chunk section). The same applies to the sky light mask and the empty sky light mask.

Login (play)

Huh.png The following information needs to be added to this page:
Although the number of portal cooldown ticks is included in this packet, the whole portal usage process is still dictated entirely by the server. What kind of effect does this value have on the client, if any?

See Protocol Encryption for information on logging in.

Packet ID State Bound To Field Name Field Type Notes
0x29 Play Client Entity ID Int The player's Entity ID (EID).
Is hardcore Boolean
Dimension Count VarInt Size of the following array.
Dimension Names Array of Identifier Identifiers for all dimensions on the server.
Max Players VarInt Was once used by the client to draw the player list, but now is ignored.
View Distance VarInt Render distance (2-32).
Simulation Distance VarInt The distance that the client will process specific things, such as entities.
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.
Do limited crafting Boolean Whether players can only craft recipes they have already unlocked. Currently unused by the client.
Dimension Type Identifier The type of dimension in the minecraft:dimension_type registry, defined by the Registry Data packet.
Dimension Name Identifier Name of the dimension being spawned into.
Hashed seed Long First 8 bytes of the SHA-256 hash of the world's seed. Used client side for biome noise
Game mode Unsigned Byte 0: Survival, 1: Creative, 2: Adventure, 3: Spectator.
Previous Game mode Byte -1: Undefined (null), 0: Survival, 1: Creative, 2: Adventure, 3: Spectator. The previous game mode. Vanilla client uses this for the debug (F3 + N & F3 + F4) game mode switch. (More information needed)
Is Debug Boolean True if the world is a debug mode world; debug mode worlds cannot be modified and have predefined blocks.
Is Flat Boolean True if the world is a superflat world; flat worlds have different void fog and a horizon at y=0 instead of y=63.
Has death location Boolean If true, then the next two fields are present.
Death dimension name Optional Identifier Name of the dimension the player died in.
Death location Optional Position The location that the player died at.
Portal cooldown VarInt The number of ticks until the player can use the portal again.

Map Data

Updates a rectangular area on a map item.

Packet ID State Bound To Field Name Field Type Notes
0x2A 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)
Locked Boolean True if the map has been locked in a cartography table
Has Icons Boolean
Icon Count Optional VarInt Number of elements in the following array. Only present if previous Boolean is true.
Icon Type Optional 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 Text Component Only present if previous Boolean is true
Columns Unsigned Byte Number of columns updated
Rows Optional Unsigned 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

Merchant Offers

The list of trades a villager NPC is offering.

Packet ID State Bound To Field Name Field Type Notes
0x2B Play Client Window ID VarInt The ID of the window that is open; this is an int rather than a byte.
Size VarInt The number of trades in the following array.
Trades Input item 1 Array Slot The first item the player has to supply for this villager trade. The count of the item stack is the default "price" of this trade.
Output item Slot The item the player will receive from this villager trade.
Input item 2 Slot The second item the player has to supply for this villager trade. May be an empty slot.
Trade disabled Boolean True if the trade is disabled; false if the trade is enabled.
Number of trade uses Int Number of times the trade has been used so far. If equal to the maximum number of trades, the client will display a red X.
Maximum number of trade uses Int Number of times this trade can be used before it's exhausted.
XP Int Amount of XP the villager will earn each time the trade is used.
Special Price Int Can be zero or negative. The number is added to the price when an item is discounted due to player reputation or other effects.
Price Multiplier Float Can be low (0.05) or high (0.2). Determines how much demand, player reputation, and temporary effects will adjust the price.
Demand Int If positive, causes the price to increase. Negative values seem to be treated the same as zero.
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.

Modifiers can increase or decrease the number of items for the first input slot. The second input slot and the output slot never change the nubmer of items. The number of items may never be less than 1, and never more than the stack size. If special price and demand are both zero, only the default price is displayed. If either is non-zero, then the adjusted price is displayed next to the crossed-out default price. The adjusted prices is calculated as follows:

Adjusted price = default price + floor(default price x multiplier x demand) + special price

The merchant UI, for reference

Update 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 Teleport Entity 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
0x2C 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

Update 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
0x2D 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

Update Entity Rotation

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

Packet ID State Bound To Field Name Field Type Notes
0x2E Play Client Entity ID VarInt
Yaw Angle New angle, not a delta.
Pitch Angle New angle, not a delta.
On Ground Boolean

Move Vehicle

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

Packet ID State Bound To Field Name Field Type Notes
0x2F 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
0x30 Play Client Hand VarInt Enum 0: Main hand, 1: Off hand .

Open Screen

This is sent to the client when it should open an inventory, such as a chest, workbench, furnace, or other container. Resending this packet with already existing window id, will update the window title and window type without closing the window.

This message is not sent to clients opening their own inventory, nor do clients inform the server in any way when doing so. From the server's perspective, the inventory is always "open" whenever no other windows are.

For horses, use Open Horse Screen.

Packet ID State Bound To Field Name Field Type Notes
0x31 Play Client Window ID VarInt An identifier for the window to be displayed. Notchian server implementation is a counter, starting at 1. There can only be one window at a time; this is only used to ignore outdated packets targeting already-closed windows. Note also that the Window ID field in most other packets is only a single byte, and indeed, the Notchian server wraps around after 100.
Window Type VarInt The window type to use for display. Contained in the minecraft:menu registry; see Inventory for the different values.
Window Title Text Component 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 Update first.

Packet ID State Bound To Field Name Field Type Notes
0x32 Play Client Location Position
Is Front Text Boolean Whether the opened editor is for the front or on the back of the sign

Ping (play)

Packet is not used by the Notchian server. When sent to the client, client responds with a Pong packet with the same id.

Packet ID State Bound To Field Name Field Type Notes
0x33 Play Client ID Int

Ping Response (play)

Packet ID State Bound To Field Name Field Type Notes
0x34 Play Client Payload Long Should be the same as sent by the client.

Place Ghost Recipe

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

Packet ID State Bound To Field Name Field Type Notes
0x35 Play Client Window ID Byte
Recipe Identifier A recipe ID.

Player Abilities (clientbound)

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

Packet ID State Bound To Field Name Field Type Notes
0x36 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 Update Attributes 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

Player Chat Message

Sends the client a chat message from a player.

Currently a lot is unknown about this packet, blank descriptions are for those that are unknown

Packet ID State Bound To Sector Field Name Field Type Notes
0x37 Play Client Header Sender UUID Used by the Notchian client for the disableChat launch option. Setting both longs to 0 will always display the message regardless of the setting.
Index VarInt
Message Signature Present Boolean States if a message signature is present
Message Signature bytes Optional Byte Array (256) Only present if Message Signature Present is true. Cryptography, the signature consists of the Sender UUID, Session UUID from the Player Session packet, Index, Salt, Timestamp in epoch seconds, the length of the original chat content, the original content itself, the length of Previous Messages, and all of the Previous message signatures. These values are hashed with SHA-256 and signed using the RSA cryptosystem. Modifying any of these values in the packet will cause this signature to fail. This buffer is always 256 bytes long and it is not length-prefixed.
Body Message String (256) Raw (optionally) signed sent message content.

This is used as the content parameter when formatting the message on the client.

Timestamp Long Represents the time the message was signed as milliseconds since the epoch, used to check if the message was received within 2 minutes of it being sent.
Salt Long Cryptography, used for validating the message signature.
Previous Messages Total Previous Messages VarInt The maximum length is 20 in Notchian client.
Array (20) Message ID VarInt The message Id + 1, used for validating message signature. The next field is present only when value of this field is equal to 0.
Signature Optional Byte Array (256) The previous message's signature. Contains the same type of data as Message Signature bytes (256 bytes) above. Not length-prefxied.
Other Unsigned Content Present Boolean True if the next field is present
Unsigned Content Optional Text Component
Filter Type VarInt Enum If the message has been filtered
Filter Type Bits Optional BitSet Only present if the Filter Type is Partially Filtered. Specifies the indexes at which characters in the original message string should be replaced with the # symbol (i.e. filtered) by the Notchian client
Chat Formatting Chat Type VarInt The type of chat in the minecraft:chat_type registry, defined by the Registry Data packet.
Sender Name Text Component The name of the one sending the message, usually the sender's display name.

This is used as the sender parameter when formatting the message on the client.

Has Target Name Boolean True if target name is present.
Target Name Optional Text Component The name of the one receiving the message, usually the receiver's display name. Only present if previous boolean is true.

This is used as the target parameter when formatting the message on the client.

Player Chat Handling Logic

Filter Types:

The filter type mask should NOT be specified unless partially filtered is selected

ID Name Description
0 PASS_THROUGH Message is not filtered at all
1 FULLY_FILTERED Message is fully filtered
2 PARTIALLY_FILTERED Only some characters in the message are filtered

End Combat

Unused by the Notchian client. This data was once used for twitch.tv metadata circa 1.8.

Packet ID State Bound To Field Name Field Type Notes
0x38 Play Client Duration VarInt Length of the combat in ticks.

Enter Combat

Unused by the Notchian client. This data was once used for twitch.tv metadata circa 1.8.

Packet ID State Bound To Field Name Field Type Notes
0x39 Play Client no fields

Combat Death

Used to send a respawn screen.

Packet ID State Bound To Field Name Field Type Notes
0x3A Play Client Player ID VarInt Entity ID of the player that died (should match the client's entity ID).
Message Text Component The death message.

Player Info Remove

Used by the server to remove players from the player list.

Packet ID State Bound To Field Name Field Type Notes
0x3B Play Client Number of Players VarInt Number of elements in the following array.
Player Player Id Array of UUID UUIDs of players to remove.

Player Info Update

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

Packet ID State Bound To Field Name Field Type Notes
0x3C Play Client Actions Byte Determines what actions are present.
Number Of Players VarInt Number of elements in the following array.
Players UUID Array UUID The player UUID
Player Actions Array of Player Actions The length of this array is determined by the number of Player Actions that give a non-zero value when applying its mask to the actions flag. For example given the decimal number 5, binary 00000101. The masks 0x01 and 0x04 would return a non-zero value, meaning the Player Actions array would include two actions: Add Player and Update Game Mode.


Player Actions
Action Mask Field Name Type Notes
Add Player 0x01 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.
Initialize Chat 0x02 Has Signature Data Boolean
Chat session ID UUID Only sent if Has Signature Data is true.
Public key expiry time Long Key expiry time, as a UNIX timestamp in milliseconds. Only sent if Has Signature Data is true.
Encoded public key size VarInt Size of the following array. Only sent if Has Signature Data is true. Maximum length is 512 bytes.
Encoded public key Byte Array (512) The player's public key, in bytes. Only sent if Has Signature Data is true.
Public key signature size VarInt Size of the following array. Only sent if Has Signature Data is true. Maximum length is 4096 bytes.
Public key signature Byte Array (4096) The public key's digital signature. Only sent if Has Signature Data is true.
Update Game Mode 0x04 Game Mode VarInt
Update Listed 0x08 Listed Boolean Whether the player should be listed on the player list.
Update Latency 0x10 Ping VarInt Measured in milliseconds.
Update Display Name 0x20 Has Display Name Boolean
Display Name Optional Text Component Only sent if Has Display Name is true.

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.

Look At

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
0x3D 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.

Synchronize Player Position

Teleports the client, e.g. during login, when using an ender pearl, in response to invalid move packets, etc.

Due to latency, the server may receive outdated movement packets sent before the client was aware of the teleport. To account for this, the server ignores all movement packets from the client until a Confirm Teleportation packet with an ID matching the one sent in the teleport packet is received.

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
0x3E 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 Reference the Flags table below. When the value of the this byte masked is zero the field is absolute, otherwise relative.
Teleport ID VarInt Client should confirm this packet with Confirm Teleportation containing the same Teleport ID.
Flags
Field Hex Mask
X 0x01
Y 0x02
Z 0x04
Y_ROT (Pitch) 0x08
X_ROT (Yaw) 0x10

Update Recipe Book

Packet ID State Bound To Field Name Field Type Notes
0x3F 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.
Blast Furnace Recipe Book Open Boolean If true, then the blast furnace recipe book will be open when the player opens its inventory.
Blast Furnace Recipe Book Filter Active Boolean If true, then the filtering option is active when the players opens its inventory.
Smoker Recipe Book Open Boolean If true, then the smoker recipe book will be open when the player opens its inventory.
Smoker 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 list 1 will be tagged as displayed, and all the recipes in list 2 will be added to the recipe book. Recipes that aren't tagged will be shown in the notification.
  • 1 (add) = All the recipes in the list are added to the recipe book and their icons will be shown in the notification.
  • 2 (remove) = Remove all the recipes in the list. This allows them to be re-displayed when they are re-added.

Remove Entities

Sent by the server when an entity is to be destroyed on the client.

Packet ID State Bound To Field Name Field Type Notes
0x40 Play Client Count VarInt Number of elements in the following array.
Entity IDs Array of VarInt The list of entities to destroy.

Remove Entity Effect

Packet ID State Bound To Field Name Field Type Notes
0x41 Play Client Entity ID VarInt
Effect ID VarInt See this table.

Reset Score

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

Packet ID State Bound To Field Name Field Type Notes
0x42 Play Client Entity Name String (32767) The entity whose score this is. For players, this is their username; for other entities, it is their UUID.
Has Objective Name Boolean Whether the score should be removed for the specified objective, or for all of them.
Objective Name Optional String (32767) The name of the objective the score belongs to. Only present if the previous field is true.

Remove Resource Pack (play)

Packet ID State Bound To Field Name Field Type Notes
0x43 Play Client Has UUID Boolean Whether a specific resource pack should be removed, or all of them.
UUID Optional UUID The UUID of the resource pack to be removed. Only present if the previous field is true.

Add Resource Pack (play)

Packet ID State Bound To Field Name Field Type Notes
0x44 Play Client UUID UUID The unique identifier of the resource pack.
URL String (32767) The URL to the resource pack.
Hash String (40) A 40 character hexadecimal, case-insensitive SHA-1 hash of the resource pack file.
If it's not a 40 character hexadecimal string, the client will not use it for hash verification and likely waste bandwidth.
Forced Boolean The Notchian client will be forced to use the resource pack from the server. If they decline they will be kicked from the server.
Has Prompt Message Boolean Whether a custom message should be used on the resource pack prompt.
Prompt Message Optional Text Component This is shown in the prompt making the client accept or decline the resource pack. Only present if the previous field is true.

Respawn

Huh.png The following information needs to be added to this page:
Although the number of portal cooldown ticks is included in this packet, the whole portal usage process is still dictated entirely by the server. What kind of effect does this value have on the client, if any?

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
0x45 Play Client Dimension Type Identifier The type of dimension in the minecraft:dimension_type registry, defined by the Registry Data packet.
Dimension Name Identifier Name of the dimension being spawned into.
Hashed seed Long First 8 bytes of the SHA-256 hash of the world's seed. Used client side for biome noise
Game mode Unsigned Byte 0: Survival, 1: Creative, 2: Adventure, 3: Spectator.
Previous Game mode Byte -1: Undefined (null), 0: Survival, 1: Creative, 2: Adventure, 3: Spectator. The previous game mode. Vanilla client uses this for the debug (F3 + N & F3 + F4) game mode switch. (More information needed)
Is Debug Boolean True if the world is a debug mode world; debug mode worlds cannot be modified and have predefined blocks.
Is Flat Boolean True if the world is a superflat world; flat worlds have different void fog and a horizon at y=0 instead of y=63.
Has death location Boolean If true, then the next two fields are present.
Death dimension Name Optional Identifier Name of the dimension the player died in.
Death location Optional Position The location that the player died at.
Portal cooldown VarInt The number of ticks until the player can use the portal again.
Data kept Byte Bit mask. 0x01: Keep attributes, 0x02: Keep metadata. Tells which data should be kept on the client side once the player has respawned.

In the Notchian implementation, this is context dependent:

  • normal respawns (after death) keep no data;
  • exiting the end poem/credits keeps the attributes;
  • other dimension changes (portals or teleports) keep all data.

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).

Before 1.16, 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.

Set Head Rotation

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
0x46 Play Client Entity ID VarInt
Head Yaw Angle New angle, not a delta.

Update Section Blocks

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 Update).

Packet ID State Bound To Field Name Field Type Notes
0x47 Play Client Chunk section position Long Chunk section coordinate (encoded chunk x and z with each 22 bits, and section y with 20 bits, from left to right).
Blocks array size VarInt Number of elements in the following array.
Blocks Array of VarLong Each entry is composed of the block state id, shifted left by 12, and the relative block position in the chunk section (4 bits for x, z, and y, from left to right).

Chunk section position is encoded:

((sectionX & 0x3FFFFF) << 42) | (sectionY & 0xFFFFF) | ((sectionZ & 0x3FFFFF) << 20);

and decoded:

sectionX = long >> 42;
sectionY = long << 44 >> 44;
sectionZ = long << 22 >> 42;

Blocks are encoded:

blockStateId << 12 | (blockLocalX << 8 | blockLocalZ << 4 | blockLocalY)
//Uses the local position of the given block position relative to its respective chunk section

and decoded:

blockStateId = long >> 12;
blockLocalX = (long >> 8) & 0xF;
blockLocalY = long & 0xF;
blockLocalZ = (long >> 4) & 0xF;

Select Advancements 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
0x48 Play Client Has id Boolean Indicates if the next field is present.
Identifier Optional Identifier See below.

The Identifier can be one of the following:

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.

Server Data

Packet ID State Bound To Field Name Field Type Notes
0x49 Play Client MOTD Text Component
Has Icon Boolean
Size VarInt Number of bytes in the following array.
Icon Optional Byte Array Icon bytes in the PNG format
Enforces Secure Chat Boolean

Set Action Bar Text

Displays a message above the hotbar. Equivalent to System Chat Message with Overlay set to true, except that chat message blocking isn't performed. Used by the Notchian server only to implement the /title command.

Packet ID State Bound To Field Name Field Type Notes
0x4A Play Client Action bar text Text Component

Set Border Center

Packet ID State Bound To Field Name Field Type Notes
0x4B Play Client X Double
Z Double

Set Border Lerp Size

Packet ID State Bound To Field Name Field Type Notes
0x4C Play Client 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.

Set Border Size

Packet ID State Bound To Field Name Field Type Notes
0x4D Play Client Diameter Double Length of a single side of the world border, in meters.

Set Border Warning Delay

Packet ID State Bound To Field Name Field Type Notes
0x4E Play Client Warning Time VarInt In seconds as set by /worldborder warning time.

Set Border Warning Distance

Packet ID State Bound To Field Name Field Type Notes
0x4F Play Client Warning Blocks VarInt In meters.

Set 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
0x50 Play Client Camera ID VarInt ID of the entity to set the client's camera to.

The notchian client 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

Set Held Item (clientbound)

Sent to change the player's slot selection.

Packet ID State Bound To Field Name Field Type Notes
0x51 Play Client Slot Byte The slot which the player has selected (0–8).

Set Center Chunk

Sets the center position of the client's chunk loading area. The area is square-shaped, spanning 2 × server view distance + 7 chunks on both axes (width, not radius!). Since the area's width is always an odd number, there is no ambiguity as to which chunk is the center.

The Notchian client ignores attempts to send chunks located outside the loading area, and immediately unloads any existing chunks no longer inside it.

The center chunk is normally the chunk the player is in, but apart from the implications on chunk loading, the (Notchian) client takes no issue with this not being the case. Indeed, as long as chunks are sent only within the default loading area centered on the world origin, it is not necessary to send this packet at all. This may be useful for servers with small bounded worlds, such as minigames, since it ensures chunks never need to be resent after the client has joined, saving on bandwidth.

The Notchian server sends this packet 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
0x52 Play Client Chunk X VarInt Chunk X coordinate of the loading area center.
Chunk Z VarInt Chunk Z coordinate of the loading area center.

Set Render Distance

Sent by the integrated singleplayer server when changing render distance. This packet is sent by the server when the client reappears in the overworld after leaving the end.

Packet ID State Bound To Field Name Field Type Notes
0x53 Play Client View Distance VarInt Render distance (2-32).

Set Default 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
0x54 Play Client Location Position Spawn location.
Angle Float The angle at which to respawn at.

Display Objective

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

Packet ID State Bound To Field Name Field Type Notes
0x55 Play Client Position VarInt 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 (32767) The unique name for the scoreboard to be displayed.

Set 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
0x56 Play Client Entity ID VarInt
Metadata Entity Metadata

Link Entities

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

Packet ID State Bound To Field Name Field Type Notes
0x57 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.

Set Entity Velocity

Velocity is 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
0x58 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.

Set Equipment

Packet ID State Bound To Field Name Field Type Notes
0x59 Play Client Entity ID VarInt Entity's ID.
Equipment Slot Array Byte Enum Equipment slot. 0: main hand, 1: off hand, 2–5: armor slot (2: boots, 3: leggings, 4: chestplate, 5: helmet). Also has the top bit set if another entry follows, and otherwise unset if this is the last item in the array.
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
0x5A 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.

Set Health

Sent by the server to 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. New players logging in or respawning 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
0x5B 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.

Update Objectives

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
0x5C Play Client Objective Name String (32767) A 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 Text Component 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".
Has Number Format Optional Boolean Only if mode is 0 or 2. Whether this objective has a set number format for the scores.
Number Format Optional VarInt Enum Only if mode is 0 or 2 and the previous boolean is true. Determines how the score number should be formatted.
Number Format Field Name
0: blank no fields Show nothing.
1: styled Styling Compound Tag The styling to be used when formatting the score number. Contains the text component styling fields.
2: fixed Content Text Component The text to be used as placeholder.

Set Passengers

Packet ID State Bound To Field Name Field Type Notes
0x5D 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.

Update Teams

Creates and updates teams.

Packet ID State Bound To Field Name Field Type Notes
0x5E Play Client Team Name String (32767) A unique name for the team. (Shared with scoreboard).
Mode Byte Determines the layout of the remaining packet.
0: create team Team Display Name Text Component
Friendly Flags Byte Bit mask. 0x01: Allow friendly fire, 0x02: can see invisible players on same team.
Name Tag Visibility String Enum (40) always, hideForOtherTeams, hideForOwnTeam, never.
Collision Rule String Enum (40) always, pushOtherTeams, pushOwnTeam, never.
Team Color VarInt Enum Used to color the name of players on the team; see below.
Team Prefix Text Component Displayed before the names of players that are part of this team.
Team Suffix Text Component 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 (32767) 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 Text Component
Friendly Flags Byte Bit mask. 0x01: Allow friendly fire, 0x02: can see invisible entities on same team.
Name Tag Visibility String Enum (40) always, hideForOtherTeams, hideForOwnTeam, never
Collision Rule String Enum (40) always, pushOtherTeams, pushOwnTeam, never
Team Color VarInt Enum Used to color the name of players on the team; see below.
Team Prefix Text Component Displayed before the names of players that are part of this team.
Team Suffix Text Component Displayed after the names of players that are part of this team.
3: add entities to team Entity Count VarInt Number of elements in the following array.
Entities Array of String (32767) Identifiers for the added entities. For players, this is their username; for other entities, it is their UUID.
4: remove entities from team Entity Count VarInt Number of elements in the following array.
Entities Array of String (32767) Identifiers for the removed entities. 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 in Text formatting#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
0x5F Play Client Entity Name String (32767) The entity whose score this is. For players, this is their username; for other entities, it is their UUID.
Objective Name String (32767) The name of the objective the score belongs to.
Value VarInt The score to be displayed next to the entry.
Has Display Name Boolean Whether this score has a custom display name.
Display Name Optional Text Component The custom display name. Only present if the previous boolean is true.
Has Number Format Boolean Whether this score has a set number format. This overrides the number format set on the objective, if any.
Number Format Optional VarInt Enum Determines how the score number should be formatted. Only present if the previous boolean is true.
Number Format Field Name
0: blank no fields Show nothing.
1: styled Styling Compound Tag The styling to be used when formatting the score number. Contains the text component styling fields.
2: fixed Content Text Component The text to be used as placeholder.

Set Simulation Distance

Packet ID State Bound To Field Name Field Type Notes
0x60 Play Client Simulation Distance VarInt The distance that the client will process specific things, such as entities.

Set Subtitle Text

Packet ID State Bound To Field Name Field Type Notes
0x61 Play Client Subtitle Text Text Component

Update Time

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
0x62 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.

Set Title Text

Packet ID State Bound To Field Name Field Type Notes
0x63 Play Client Title Text Text Component

Set Title Animation Times

Packet ID State Bound To Field Name Field Type Notes
0x64 Play Client Fade In Int Ticks to spend fading in.
Stay Int Ticks to keep the title displayed.
Fade Out Int Ticks to spend fading out, not when to start fading out.

Entity Sound Effect

Plays a sound effect from an entity, either by hardcoded ID or Identifier. Sound IDs and names can be found here.

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

Packet ID State Bound To Field Name Field Type Notes
0x65 Play Client Sound ID VarInt Represents the Sound ID + 1. If the value is 0, the packet contains a sound specified by Identifier.
Sound Name Optional Identifier Only present if Sound ID is 0
Has Fixed Range Optional Boolean Only present if Sound ID is 0.
Range Optional Float The fixed range of the sound. Only present if previous boolean is true and Sound ID is 0.
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.
Seed Long Seed used to pick sound variant.

Sound Effect

Plays a sound effect at the given location, either by hardcoded ID or Identifier. Sound IDs and names can be found here.

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

Packet ID State Bound To Field Name Field Type Notes
0x66 Play Client Sound ID VarInt Represents the Sound ID + 1. If the value is 0, the packet contains a sound specified by Identifier.
Sound Name Optional Identifier Only present if Sound ID is 0
Has Fixed Range Optional Boolean Only present if Sound ID is 0.
Range Optional Float The fixed range of the sound. Only present if previous boolean is true and Sound ID is 0.
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.
Seed Long Seed used to pick sound variant.

Start Configuration

Sent during gameplay in order to redo the configuration process. The client must respond with Acknowledge Configuration for the process to start.

Packet ID State Bound To Field Name Field Type Notes
0x67 Play Client no fields

This packet switches the connection state to configuration.

Stop Sound

Packet ID State Bound To Field Name Field Type Notes
0x68 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 Custom 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

System Chat Message

Sends the client a raw system message.

Packet ID State Bound To Field Name Field Type Notes
0x69 Play Client Content Text Component Limited to 262144 bytes.
Overlay Boolean Whether the message is an actionbar or chat message. See also #Set Action Bar Text.

Set Tab 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
0x6A Play Client Header Text Component To remove the header, send a empty text component: {"text":""}.
Footer Text Component To remove the footer, send a empty text component: {"text":""}.

Tag Query Response

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

Packet ID State Bound To Field Name Field Type Notes
0x6B Play Client Transaction ID VarInt Can be compared to the one sent in the original query packet.
NBT NBT The NBT of the block or entity. May be a TAG_END (0) in which case no NBT is present.

Pickup 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 Set Player Position (and Set Player Position And Rotation) 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
0x6C 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.

Teleport Entity

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
0x6D Play Client Entity ID VarInt
X Double
Y Double
Z Double
Yaw Angle (Y Rot)New angle, not a delta.
Pitch Angle (X Rot)New angle, not a delta.
On Ground Boolean

Set Ticking State

Used to adjust the ticking rate of the client, and whether it's frozen.

Packet ID State Bound To Field Name Field Type Notes
0x6E Play Client Tick rate Float
Is frozen Boolean

Step Tick

Advances the client processing by the specified number of ticks. Has no effect unless client ticking is frozen.

Packet ID State Bound To Field Name Field Type Notes
0x6F Play Client Tick steps VarInt

Update Advancements

Packet ID State Bound To Field Name Field Type Notes
0x70 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.
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 (32767) Array of required criteria.
Sends telemetry data Boolean Whether the client should include this achievement in the telemetry data when it's completed.

The Notchian client only sends data for advancements on the minecraft namespace.

Advancement display:

Field Name Field Type Notes
Title Text Component
Description Text Component
Icon Slot
Frame type VarInt Enum 0 = task, 1 = challenge, 2 = goal.
Flags Int 0x01: has background texture; 0x02: show_toast; 0x04: 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.

Update Attributes

Sets attributes on the given entity.

Packet ID State Bound To Field Name Field Type Notes
0x71 Play Client Entity ID VarInt
Number Of Properties VarInt Number of elements in the following array.
Property Key Array Identifier See below.
Value Double See below.
Number Of Modifiers VarInt Number of elements in the following array.
Modifiers Array of Modifier Data See Attribute#Modifiers. Modifier Data defined below.

Known Key values (see also Attribute#Modifiers):

Key Default Min Max Label
generic.max_health 20.0 1.0 1024.0 Max Health.
generic.follow_range 32.0 0.0 2048.0 Follow Range.
generic.knockback_resistance 0.0 0.0 1.0 Knockback Resistance.
generic.movement_speed 0.7 0.0 1024.0 Movement Speed.
generic.flying_speed 0.4 0.0 1024.0 Flying Speed.
generic.attack_damage 2.0 0.0 2048.0 Attack Damage.
generic.attack_knockback 0.0 0.0 5.0
generic.attack_speed 4.0 0.0 1024.0 Attack Speed.
generic.armor 0.0 0.0 30.0 Armor.
generic.armor_toughness 0.0 0.0 20.0 Armor Toughness.
generic.luck 0.0 -1024.0 1024.0 Luck.
zombie.spawn_reinforcements 0.0 0.0 1.0 Spawn Reinforcements Chance.
horse.jump_strength 0.7 0.0 2.0 Jump Strength.
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).

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
0x72 Play Client Entity ID VarInt
Effect ID VarInt See this table.
Amplifier Byte Notchian client displays effect level as Amplifier + 1.
Duration VarInt Duration in ticks. (-1 for infinite)
Flags Byte Bit field, see below.
Has Factor Data Boolean Used in DARKNESS effect
Factor Codec NBT 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.

Factor Data

Name Type Notes
padding_duration TAG_INT
factor_start TAG_FLOAT
factor_target TAG_FLOAT
factor_current TAG_FLOAT
effect_changed_timestamp TAG_INT
factor_previous_frame TAG_FLOAT
had_effect_last_tick TAG_BOOLEAN

Update Recipes

Packet ID State Bound To Field Name Field Type Notes
0x73 Play Client Num Recipes VarInt Number of elements in the following array.
Recipe Type Array Identifier The recipe type, see below.
Recipe ID Identifier
Data Varies Additional data for the recipe.

Recipe types:

Type Description Data
minecraft: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 (32767) Used to group similar recipes together in the recipe book. Tag is present in recipe JSON.
Category VarInt Enum Building = 0, Redstone = 1, Equipment = 2, Misc = 3
Ingredient count VarInt Number of elements in the following array.
Ingredients Array of Ingredient.
Result Slot
minecraft: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
Group String (32767) Used to group similar recipes together in the recipe book. Tag is present in recipe JSON.
Category VarInt Enum Building = 0, Redstone = 1, Equipment = 2, Misc = 3
Width VarInt
Height VarInt
Ingredients Array of Ingredient Length is width * height. Indexed by x + (y * width).
Result Slot
Show notification Boolean Show a toast when the recipe is added.
minecraft:crafting_special_armordye Recipe for dying leather armor As follows:
Name Type Description
Category VarInt Enum Building = 0, Redstone = 1, Equipment = 2, Misc = 3
minecraft:crafting_special_bookcloning Recipe for copying contents of written books
minecraft:crafting_special_mapcloning Recipe for copying maps
minecraft:crafting_special_mapextending Recipe for adding paper to maps
minecraft:crafting_special_firework_rocket Recipe for making firework rockets
minecraft:crafting_special_firework_star Recipe for making firework stars
minecraft:crafting_special_firework_star_fade Recipe for making firework stars fade between multiple colors
minecraft:crafting_special_repairitem Recipe for repairing items via crafting
minecraft:crafting_special_tippedarrow Recipe for crafting tipped arrows
minecraft:crafting_special_bannerduplicate Recipe for copying banner patterns
minecraft:crafting_special_shielddecoration Recipe for applying a banner's pattern to a shield
minecraft:crafting_special_shulkerboxcoloring Recipe for recoloring a shulker box
minecraft:crafting_special_suspiciousstew Recipe for crafting suspicious stews
minecraft:crafting_decorated_pot Recipe for crafting decorated pots
minecraft:smelting Smelting recipe As follows:
Name Type Description
Group String (32767) Used to group similar recipes together in the recipe book.
Category VarInt Enum Food = 0, Blocks = 1, Misc = 2
Ingredient Ingredient
Result Slot
Experience Float
Cooking time VarInt
minecraft:blasting Blast furnace recipe
minecraft:smoking Smoker recipe
minecraft:campfire_cooking Campfire recipe
minecraft:stonecutting Stonecutter recipe As follows:
Name Type Description
Group String (32767) Used to group similar recipes together in the recipe book. Tag is present in recipe JSON.
Ingredient Ingredient
Result Slot
minecraft:smithing_transform Recipe for smithing netherite gear As follows:
Name Type Description
Template Ingredient The smithing template.
Base Ingredient The base item.
Addition Ingredient The additional ingredient.
Result Slot
minecraft:smithing_trim Recipe for applying armor trims As follows:
Name Type Description
Template Ingredient The smithing template.
Base Ingredient The base item.
Addition Ingredient The additional ingredient.

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.

Update Tags (play)

Packet ID State Bound To Field Name Field Type Notes
0x74 Play Client Length of the array VarInt
Array of tags Registry Array Identifier Registry identifier (Vanilla expects tags for the registries minecraft:block, minecraft:item, minecraft:fluid, minecraft:entity_type, and minecraft:game_event)
Array of Tag (See below)

Tag arrays 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 IDs of the given type (block, item, etc.). This list replaces the previous list of IDs for the given tag. If some preexisting tags are left unmentioned, a warning is printed.

See Tag on the Minecraft Wiki for more information, including a list of vanilla tags.

Serverbound

Confirm Teleportation

Sent by client as confirmation of Synchronize Player Position.

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

Query Block Entity Tag

Used when 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.

Change 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 .

Acknowledge Message

Packet ID State Bound To Field Name Field Type Notes
0x03 Play Server Message Count VarInt

Chat Command

Packet ID State Bound To Field Name Field Type Notes
0x04 Play Server Command String (256) The command typed by the client.
Timestamp Long The timestamp that the command was executed.
Salt Long The salt for the following argument signatures.
Array length VarInt Number of entries in the following array. The maximum length in Notchian server is 8.
Array of argument signatures Argument name Array (8) String (16) The name of the argument that is signed by the following signature.
Signature Byte Array (256) The signature that verifies the argument. Always 256 bytes and is not length-prefixed.
Message Count VarInt
Acknowledged Fixed BitSet (20)

Chat Message

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.

The server will broadcast a Player Chat Message packet with Chat Type minecraft:chat to all players that haven't disabled chat (including the player that sent the message). See Chat#Processing chat for more information.

Packet ID State Bound To Field Name Field Type Notes
0x05 Play Server Message String (256)
Timestamp Long
Salt Long The salt used to verify the signature hash.
Has Signature Boolean Whether the next field is present.
Signature Optional Byte Array (256) The signature used to verify the chat message's authentication. When present, always 256 bytes and not length-prefixed.
Message Count VarInt
Acknowledged Fixed BitSet (20)

Player Session

Packet ID State Bound To Field Name Field Type Notes
0x06 Play Server Session Id UUID
Public Key Expires At Long The time the play session key expires in epoch milliseconds.
Public Key Length VarInt Length of the proceeding public key. Maximum length in Notchian server is 512 bytes.
Public Key Byte Array (512) A byte array of an X.509-encoded public key.
Key Signature Length VarInt Length of the proceeding key signature array. Maximum length in Notchian server is 4096 bytes.
Key Signature Byte Array (4096) The signature consists of the player UUID, the key expiration timestamp, and the public key data. These values are hashed using SHA-1 and signed using Mojang's private RSA key.

Chunk Batch Received

Notifies the server that the chunk batch has been received by the client. The server uses the value sent in this packet to adjust the number of chunks to be sent in a batch.

The Notchian server will stop sending further chunk data until the client acknowledges the sent chunk batch. After the first acknowledgement, the server adjusts this number to allow up to 10 unacknowledged batches.

Packet ID State Bound To Field Name Field Type Notes
0x07 Play Server Chunks per tick Float Desired chunks per tick.

Client Status

Packet ID State Bound To Field Name Field Type Notes
0x08 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 Information (play)

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

Packet ID State Bound To Field Name Field Type Notes
0x09 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 Chat#Client chat mode for more information.
Chat Colors Boolean “Colors” multiplayer setting. Can the chat be colored?
Displayed Skin Parts Unsigned Byte Bit mask, see below.
Main Hand VarInt Enum 0: Left, 1: Right.
Enable text filtering Boolean Enables filtering of text on signs and written book titles. Currently always false (i.e. the filtering is disabled)
Allow server listings Boolean Servers usually list online players, this option should let you not show up in that list.

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.

Command Suggestions Request

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

Packet ID State Bound To Field Name Field Type Notes
0x0A Play Server Transaction Id VarInt The id of the transaction that the server will send back to the client in the response of 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).

Acknowledge Configuration

Sent by the client upon receiving a Start Configuration packet from the server.

Packet ID State Bound To Field Name Field Type Notes
0x0B Play Server no fields

This packet switches the connection state to configuration.

Click Container 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
0x0C Play Server Window ID Byte The ID of the window sent by Open Screen.
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 Container

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

Packet ID State Bound To Field Name Field Type Notes
0x0D Play Server Window ID Unsigned Byte The ID of the window which was clicked. 0 for player inventory. The server ignores any packets targeting a Window ID other than the current one, including ignoring 0 when any other window is open.
State ID VarInt The last received State ID from either a Set Container Slot or a Set Container Content packet.
Slot Short The clicked slot number, see below.
Button Byte The button used in the click, see below.
Mode VarInt Enum Inventory operation mode, see below.
Length of the array VarInt Maximum value for Notchian server is 128 slots.
Array of changed slots Slot number Array (128) Short
Slot data Slot New data for this slot, in the client's opinion; see below.
Carried item Slot Item carried by the cursor. Has to be empty (item ID = -1) for drop mode, otherwise nothing will happen.

See Inventory for further information about how slots are indexed.

After performing the action, the server compares the results to the slot change information included in the packet, as applied on top of the server's view of the container's state prior to the action. For any slots that do not match, it sends Set Container Slot packets containing the correct results. If State ID does not match the last ID sent by the server, it will instead send a full Set Container Content to resynchronize the client.

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
0 -999 Left click outside inventory (drop cursor stack)
1 -999 Right click outside inventory (drop cursor single item)
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
Button is used as the slot index (impossible in vanilla clients)
40 Normal Offhand swap key F
3 2 Normal Middle click, only defined for creative players in non-player inventories.
4 0 Normal* Drop key (Q) (* Clicked item is always empty)
1 Normal* Control + Drop key (Q) (* Clicked item is always empty)
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.
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.
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.
6 0 Normal Double click
1 Normal Pickup all but check items in reverse order (impossible in vanilla clients)

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.

Close Container

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 Screen packet for the inventory.

Packet ID State Bound To Field Name Field Type Notes
0x0E Play Server Window ID Unsigned Byte This is the ID of the window that was closed. 0 for player inventory.

Change Container Slot State

This packet is sent by the client when toggling the state of a Crafter.

Packet ID State Bound To Field Name Field Type Notes
0x0F Play Server Slot ID VarInt This is the ID of the slot that was changed.
Window ID VarInt This is the ID of the window that was changed.
State Boolean The new state of the slot. True for enabled, false for disabled.

Serverbound Plugin Message (play)

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: https://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
0x10 Play Server Channel Identifier Name of the plugin channel used to send the data.
Data Byte Array (32767) Any data, depending on the channel. minecraft: channels are documented here. The length of this array must be inferred from the packet length.

In Notchian server, the maximum data length is 32767 bytes.

Edit Book

Packet ID State Bound To Field Name Field Type Notes
0x11 Play Server Slot VarInt The hotbar slot where the written book is located
Count VarInt Number of elements in the following array. Maximum array size is 200.
Entries Array (200) of String (8192) Text from each page. Maximum string length is 8192 chars.
Has title Boolean If true, the next field is present. true if book is being signed, false if book is being edited.
Title Optional String (128) Title of book.

Query Entity Tag

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

Packet ID State Bound To Field Name Field Type Notes
0x12 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

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.

The target X, Y, and Z fields represent the difference between the vector location of the cursor at the time of the packet and the entity's position.

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

Packet ID State Bound To Field Name Field Type Notes
0x13 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.
Sneaking Boolean If the client is sneaking.

Jigsaw Generate

Sent when Generate is pressed on the Jigsaw Block interface.

Packet ID State Bound To Field Name Field Type Notes
0x14 Play Server Location Position Block entity location.
Levels VarInt Value of the levels slider/max depth to generate.
Keep Jigsaws Boolean

Serverbound Keep Alive (play)

The server will frequently send out a keep-alive (see Clientbound 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
0x15 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
0x16 Play Server Locked Boolean

Set Player Position

Updates the player's XYZ position on the server.

If the player is in a vehicle, the position is ignored (but in case of Set Player Position and Rotation, the rotation is still used as normal). No validation steps other than value range clamping are performed in this case.

If the player is sleeping, the position (or rotation) is not changed, and a Synchronize Player Position is sent if the received position deviated from the server's view by more than a meter.

The Notchian server silently clamps the x and z coordinates between -30,000,000 and 30,000,000, and the y coordinate between -20,000,000 and 20,000,000. A similar condition has historically caused a kick for "Illegal position"; this is no longer the case. However, infinite or NaN coordinates (or angles) still result in a kick for multiplayer.disconnect.invalid_player_movement.

As of 1.20.4, checking for moving too fast is achieved like this (sic):

  • Each server tick, the player's current position is stored.
  • When the player moves, the offset from the stored position to the requested position is computed (Δx, Δy, Δz).
  • The requested movement distance squared is computed as Δx² + Δy² + Δz².
  • The baseline expected movement distance squared is computed based on the player's server-side velocity as Vx² + Vy² + Vz². The player's server-side velocity is a somewhat ill-defined quantity that includes among other things gravity, jump velocity and knockback, but not regular horizontal movement. A proper description would bring much of Minecraft's physics engine with it. It is accessible as the Motion NBT tag on the player entity.
  • The maximum permitted movement distance squared is computed as 100 (300 if the player is using an elytra), multiplied by the number of movement packets received since the last tick, including this one, unless that value is greater than 5, in which case no multiplier is applied.
  • If the requested movement distance squared minus the baseline distance squared is more than the maximum squared, the player is moving too fast.

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

Checking for block collisions is achieved like this:

  • A temporary collision-checked move of the player is attempted from its current position to the requested one.
  • The offset from the resulting position to the requested position is computed. If the absolute value of the offset on the y axis is less than 0.5, it (only the y component) is rounded down to 0.
  • If the magnitude of the offset is greater than 0.25 and the player isn't in creative or spectator mode, it is logged that "<player> moved wrongly!", and the player is teleported back to their current (before this packet) server-side position.
  • In addition, if the player's hitbox stationary at the requested position would intersect with a block, and they aren't in spectator mode, they are teleported back without a log message.

Checking for illegal flight is achieved like this:

  • When a movement packet is received, a flag indicating whether or not the player is floating mid-air is updated. The flag is set if the move test described above detected no collision below the player and the y component of the offset from the player's current position to the requested one is greater than -0.5, unless any of various conditions permitting flight (creative mode, elytra, levitation effect, etc., but not jumping) are met.
  • Each server tick, it is checked if the flag has been set for more than 80 consecutive ticks. If so, and the player isn't currently sleeping, dead or riding a vehicle, they are kicked for multiplayer.disconnect.flying.
Packet ID State Bound To Field Name Field Type Notes
0x17 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.

Set Player Position and Rotation

A combination of Move Player Rotation and Move Player Position.

Packet ID State Bound To Field Name Field Type Notes
0x18 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.

Set 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
0x19 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.

Set Player On Ground

This packet as well as Set Player Position, Set Player Rotation, and Set Player Position and Rotation are called the “serverbound movement packets”. Vanilla clients will send Move 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
0x1A Play Server On Ground Boolean True if the client is on the ground, false otherwise.

Move Vehicle

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

Packet ID State Bound To Field Name Field Type Notes
0x1B 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.

Paddle 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
0x1C 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 held.

Pick Item

Used to swap out an empty space on the hotbar with the item in the given inventory slot. The Notchian 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
0x1D Play Server Slot to use VarInt See Inventory.

The server first searches 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 starts a second search from the current slot and finds the first slot that does not contain an enchanted item. If there still are no slots that meet that criteria, then the server uses the currently selected slot.

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

Ping Request (play)

Packet ID State Bound To Field Name Field Type Notes
0x1E Play Server Payload Long May be any number. Notchian clients use a system-dependent time value which is counted in milliseconds.

Place Recipe

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
0x1F 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 vanilla client sends this packet when the player starts/stops flying with the Flags parameter changed accordingly.

Packet ID State Bound To Field Name Field Type Notes
0x20 Play Server Flags Byte Bit mask. 0x02: is flying.

Player Action

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 the player's eyes.

Packet ID State Bound To Field Name Field Type Notes
0x21 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).
Sequence VarInt Block change sequence number (see #Acknowledge Block Change).

Status can be one of seven values:

Value Meaning Notes
0 Started digging Sent when the player starts digging a block. If the block was instamined or the player is in creative mode, the client will not send Status = Finished digging, and will assume the server completed the destruction. To detect this, it is necessary to calculate the block destruction speed server-side.
1 Cancelled digging Sent when the player lets go of the Mine Block key (default: left click). Face is always set to -Y.
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: Control or Command, depending on OS). Location is always set to 0/0/0, Face is always set to -Y. Sequence is always set to 0.
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. Sequence is always set to 0.
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. Sequence is always set to 0.
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. Sequence is always set to 0.

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

Player Command

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
0x22 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 vehicle 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 in the morning.

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

Player Input

Packet ID State Bound To Field Name Field Type Notes
0x23 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.

Pong (play)

Response to the clientbound packet (Ping) with the same id.

Packet ID State Bound To Field Name Field Type Notes
0x24 Play Server ID Int id is the same as the ping packet

Change Recipe Book Settings

Replaces Recipe Book Data, type 1.

Packet ID State Bound To Field Name Field Type Notes
0x25 Play Server Book ID VarInt Enum 0: crafting, 1: furnace, 2: blast furnace, 3: smoker.
Book Open Boolean
Filter Active Boolean

Set Seen Recipe

Sent when recipe is first seen in recipe book. Replaces Recipe Book Data, type 0.

Packet ID State Bound To Field Name Field Type Notes
0x26 Play Server Recipe ID Identifier

Rename Item

Sent as a player is renaming an item in an anvil (each keypress in the anvil UI sends a new Rename 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 50 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
0x27 Play Server Item name String (32767) The new name of the item.

Resource Pack Response (play)

Packet ID State Bound To Field Name Field Type Notes
0x28 Play Server
UUID UUID The unique identifier of the resource pack received in the Add Resource Pack (play) request.
Result VarInt Enum Result ID (see below).

Result can be one of the following values:

ID Result
0 Successfully downloaded
1 Declined
2 Failed to download
3 Accepted
4 Invalid URL
5 Failed to reload
6 Discarded


Seen Advancements

Packet ID State Bound To Field Name Field Type Notes
0x29 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
0x2A Play Server Selected slot VarInt The selected slot in the players current (trading) inventory.

Set Beacon Effect

Changes the effect of the current beacon.

Packet ID State Bound To Field Name Field Type Notes
0x2B Play Server
Has Primary Effect Boolean
Primary Effect VarInt A Potion ID.
Has Secondary Effect Boolean
Secondary Effect VarInt A Potion ID.

Set Held Item (serverbound)

Sent when the player changes the slot selection.

Packet ID State Bound To Field Name Field Type Notes
0x2C Play Server Slot Short The slot which the player has selected (0–8).

Program Command Block

Packet ID State Bound To Field Name Field Type Notes
0x2D 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.

Program Command Block Minecart

Packet ID State Bound To Field Name Field Type Notes
0x2E Play Server Entity ID VarInt
Command String (32767)
Track Output Boolean If false, the output of the previous command will not be stored within the command block.

Set Creative Mode Slot

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
0x2F Play Server Slot Short Inventory slot.
Clicked Item Slot

Program Jigsaw Block

Sent when Done is pressed on the Jigsaw Block interface.

Packet ID State Bound To Field Name Field Type Notes
0x30 Play Server Location Position Block entity location
Name Identifier
Target Identifier
Pool Identifier
Final state String (32767) "Turns into" on the GUI, final_state in NBT.
Joint type String (32767) rollable if the attached piece can be rotated, else aligned.
Selection priority VarInt
Placement priority VarInt


Program Structure Block

Packet ID State Bound To Field Name Field Type Notes
0x31 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 (32767)
Offset X Byte Between -48 and 48.
Offset Y Byte Between -48 and 48.
Offset Z Byte Between -48 and 48.
Size X Byte Between 0 and 48.
Size Y Byte Between 0 and 48.
Size Z Byte Between 0 and 48.
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 (128)
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
0x32 Play Server Location Position Block Coordinates.
Is Front Text Boolean Whether the updated text is in front or on the back of the sign
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.

Swing Arm

Sent when the player's arm swings.

Packet ID State Bound To Field Name Field Type Notes
0x33 Play Server Hand VarInt Enum Hand used for the animation. 0: main hand, 1: off hand.

Teleport To Entity

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
0x34 Play Server Target Player UUID UUID of the player to teleport to (can also be an entity UUID).

Use Item On

Packet ID State Bound To Field Name Field Type Notes
0x35 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 Action).
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.
Sequence VarInt Block change sequence number (see #Acknowledge Block Change).

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
0x36 Play Server Hand VarInt Enum Hand used for the animation. 0: main hand, 1: off hand.
Sequence VarInt Block change sequence number (see #Acknowledge Block Change).