Minecraft:Java Edition protocol/Packets

This article presents a dissection of the current Template:JE protocol for 26.2, protocol 776.

The changes between versions may be viewed at Protocol History.

Definitions

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

Data types

Java Edition protocol/Data types

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. The same entity is not guaranteed to always have the same EID. The EID is set every time an entity appears on a world, so it is recomputed every time the entity changes dimension, gets unloaded and re-loaded, etc.
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, blocks or biomes. The entries of a registry are associated 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 registries, such as biomes and dimensions, can be customized at runtime by the server (see Minecraft:Java Edition protocol/Registries#Synchronized registries), 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 global block state palette 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 -DbundlerMainClass=net.minecraft.data.Main -jar minecraft_server.jar --reports. See Data Generators for more information.
Vanilla	The official implementation of 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. It is also 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 Template:Type). 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	Template:Type	Length of Packet ID + Data
Packet ID	Template:Type	Corresponds to protocol_id from the server's packet report
Data	Template:Type	Depends on the connection state and packet ID, see the sections below

With compression

Once a Template:Packet 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.

Present?	Compressed?	Field Name	Field Type	Notes
always	No	Packet Length	Template:Type	Length of (Data Length) + length of compressed (Packet ID + Data)
if size >= threshold	No	Data Length	Template:Type	Length of uncompressed (Packet ID + Data)
	Yes	Packet ID	Template:Type	zlib compressed packet ID (see the sections below)
		Data	Template:Type	zlib compressed packet data (see the sections below)
if size < threshold	No	Data Length	Template:Type	0 to indicate uncompressed
		Packet ID	Template:Type	packet ID (see the sections below)
		Data	Template:Type	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. Note that a length equal to 2²³ is permitted, which differs from the compressed length limit. The vanilla 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 Template:Type) is smaller than the threshold specified in the packet Template:Packet. It will be sent as uncompressed. This is done by setting the data length to 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 vanilla 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 Template:Packet with a negative Threshold, or not sending the Set Compression packet at all.

List of packets

Note: The packet IDs listed here are valid only for the protocol version documented on this page, currently 773. The IDs tend to move around as packets are added and removed, so hardcoding them is highly discouraged. A list of packet IDs and corresponding official names for any version since 1.21 (protocol 767) can be obtained from the built-in data generators.

Handshaking

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Status

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Login

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Configuration

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Play

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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 packet causes the server to switch into the target state. It should be sent right after opening the TCP connection to prevent the server from disconnecting.

Template:Packet header
Field Name	Field Type	Notes
Protocol Version	Template:Type	See protocol version numbers (currently 776 in Minecraft 26.2).
Server Address	Template:Type (255)	Hostname or IP, e.g. localhost or 127.0.0.1, that was used to connect. The vanilla server does not use this information. This is the name obtained after SRV record resolution, except in 1.17 (and no older or newer version) and during server list ping (MC-278651), where it is the host portion of the address specified by the user directly. In 1.17.1 and later if a literal IP address is specified by the user, reverse DNS lookup is attempted, and the result is used as the value of this field if successful.
Server Port	Template:Type	Default is 25565. The vanilla server does not use this information.
Intent	Template:Type Template:Type	1 for Status, 2 for Login, 3 for Transfer. Intents 2 and 3 both transition to the Login state, but 3 indicates that the client is connecting due to a Template:Packet packet received from another server. If the server is not expecting transfers, it may choose to reject the connection by replying with a Template:Packet packet.

Legacy Server List Ping

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.

Modern clients (tested with 1.21.5 + 1.21.4) also send this packet when the server does not send any response within a 30 seconds time window or when the connection is immediately closed. Template:Warning

Packet ID	State	Bound To	Field Name	Field Type	Notes
0xFE	Handshaking	Server	Payload	Template:Type	always 1 (0x01).

See Minecraft:Java Edition protocol/Server List Ping#1.6 for the details of the protocol that follows this packet.

Status

Clientbound

Status Response

Template:Packet header
Field Name	Field Type	Notes
JSON Response	Template:Type (32767)	See Minecraft:Java Edition protocol/Server List Ping#Status Response; as with all strings, this is prefixed by its length as a Template:Type.

Pong Response (status)

Template:Packet header
Field Name	Field Type	Notes
Timestamp	Template:Type	Should match the one 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.

Template:Packet header
Field Name	Field Type	Notes
no fields

Ping Request (status)

Template:Packet header
Field Name	Field Type	Notes
Timestamp	Template:Type	May be any number, but vanilla clients will always use the timestamp in milliseconds.

Login

The login process is as follows:

1. C→S: Template:Packet with intent set to 2 (login) or 3 (transfer)
2. C→S: Template:Packet
3. S→C: Template:Packet
4. Client auth (if enabled)
5. C→S: Template:Packet
6. Server auth (if enabled)
7. Both enable encryption
8. S→C: Template:Packet (optional)
9. S→C: Template:Packet
10. C→S: Template:Packet

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

Three modes of operation are possible depending on how the packets are sent:

• Online-mode with encryption
• Offline-mode with encryption
• Offline-mode without encryption

For online-mode servers (the ones with authentication enabled), encryption is always mandatory, and the entire process described above needs to be followed.

For offline-mode servers (the ones with authentication disabled), encryption is optional, and part of the process can be skipped. In that case, Template:Packet is directly followed by Template:Packet. The vanilla server only uses UUID v3 for offline player UUIDs, deriving it from the string OfflinePlayer:<player's name>. For example, Notch’s offline UUID would be chosen from the string OfflinePlayer:Notch. This is not a requirement however, the UUID can be set to anything.

As of 1.21, the vanilla server never uses encryption in offline mode.

See Minecraft:protocol encryption for details.

Clientbound

Disconnect (login)

Template:Packet header
Field Name	Field Type	Notes
Reason	Template:Type	The reason why the player was disconnected.

Encryption Request

Template:Packet header
Field Name	Field Type	Notes
Server ID	Template:Type (20)	Always empty when sent by the vanilla server.
Public Key	Template:Type of Template:Type	The server's public key, in bytes.
Verify Token	Template:Type of Template:Type	A sequence of random bytes generated by the server.
Should authenticate	Template:Type	Whether the client should attempt to authenticate through mojang servers.

See Minecraft:protocol encryption for details.

Login Success

Template:Packet header
Field Name	Field Type	Notes
Profile	Template:Type
Session ID	Template:Type

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 vanilla server does not send the packet when compression is disabled).

Template:Packet header
Field Name	Field Type	Notes
Threshold	Template:Type	Maximum size of a packet before it is compressed.

Login Plugin Request

Used to implement a custom handshaking flow together with Template:Packet.

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 vanilla client always responds that it hasn't understood and sends an empty payload.

Template:Packet header
Field Name	Field Type	Notes
Message ID	Template:Type	Generated by the server - should be unique to the connection.
Channel	Template:Type	Name of the plugin channel used to send the data.
Data	Varies	Any data, depending on the channel. Typically this would be a sequence of fields using standard data types, but some unofficial channels have unusual formats. There is no length prefix that applies to all channel types, but the format specific to the channel may or may not include one or more length prefixes (e.g. for strings). The vanilla client enforces a length limit of 1048576 bytes on this data, but only if the channel type is unrecognized (which is the case for all login plugin messages with a completely vanilla client).

Serverbound

Login Start

Template:Packet header
Field Name	Field Type	Notes
Name	Template:Type (16)	Player's Username.
Player UUID	Template:Type	The Template:Type of the player logging in. Unused by the vanilla server.

Encryption Response

Template:Packet header
Field Name	Field Type	Notes
Shared Secret	Template:Type of Template:Type	Shared Secret value, encrypted with the server's public key.
Verify Token	Template:Type of Template:Type	Verify Token value, encrypted with the same public key as the shared secret.

See Minecraft:protocol encryption for details.

Login Plugin Response

Template:Packet header
Field Name	Field Type	Notes
Message ID	Template:Type	Should match ID from server.
Data	Template:Type Varies	Any data, depending on the channel. Only present if the client understood the request. Typically this would be a sequence of fields using standard data types, but some unofficial channels have unusual formats. There is no length prefix that applies to all channel types, but the format specific to the channel may or may not include one or more length prefixes (e.g. for strings).

Login Acknowledged

Acknowledgement to the Template:Packet packet sent by the server.

Template:Packet header
Field Name	Field Type	Notes
no fields

This packet switches the connection state to configuration.

Login, configuration and play

Clientbound

Cookie Request

Requests a cookie that was previously stored.

Template:Packet header
Field Name		Field Type		Notes
Key		Template:Type		The identifier of the cookie.

Serverbound

Cookie Response

Response to a Template:Packet from the server. The vanilla server only accepts responses of up to 5 kiB in size.

Template:Packet header
Field Name	Field Type	Notes
Key	Template:Type	The identifier of the cookie.
Payload	Template:Type Template:Type (5120) of Template:Type	The data of the cookie.

Configuration and play

Clientbound

Plugin Message (clientbound)

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.

Template:Packet header
Field Name	Field Type	Notes
Channel	Template:Type	Name of the plugin channel used to send the data.
Data	Varies	Any data, depending on the channel. Typically this would be a sequence of fields using standard data types, but some unofficial channels have unusual formats. There is no length prefix that applies to all channel types, but the format specific to the channel may or may not include one or more length prefixes (such as the string length prefix in the standard minecraft:brand channel). The vanilla client enforces a length limit of 1048576 bytes on this data, but only if the channel type is unrecognized.

Disconnect

Template:Packet header
Field Name	Field Type	Notes
Reason	Template:Type	The reason why the player was disconnected.

Keep Alive (clientbound)

The server will frequently send out a keep-alive, each containing a random ID. The client must respond with the same payload (see Template:Packet). If the client does not respond to a Keep Alive packet within 15 seconds after it was sent, the server kicks the client. Vice versa, if the server does not send any keep-alives for 20 seconds, the client will disconnect and yield a "Timed out" exception.

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

Template:Packet header
Field Name	Field Type	Notes
Keep Alive ID	Template:Type

Ping

Packet is not used by the vanilla server. When sent to the client, the client responds with a Template:Packet packet with the same ID.

Template:Packet header
Field Name	Field Type	Notes
ID	Template:Type

Remove Resource Pack

Template:Packet header
Field Name	Field Type	Notes
UUID	Template:Type Template:Type	The Template:Type of the resource pack to be removed. If not present, every resource pack will be removed.

Add Resource Pack

Template:Packet header
Field Name	Field Type	Notes
UUID	Template:Type	The unique identifier of the resource pack.
URL	Template:Type (32767)	The URL to the resource pack.
Hash	Template:Type (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	Template:Type	The vanilla client will be forced to use the resource pack from the server. If they decline, they will be kicked from the server.
Prompt Message	Template:Type Template:Type	This is shown in the prompt making the client accept or decline the resource pack (only if present).

Store Cookie

Stores some arbitrary data on the client, which persists between server transfers. The vanilla client only accepts cookies of up to 5 kiB in size.

Template:Packet header
Field Name		Field Type		Notes
Key		Template:Type		The identifier of the cookie.
Payload		Template:Type (5120) of Template:Type		The data of the cookie.

Transfer

Notifies the client that it should transfer to the given server.

The client will close its connection to the current server, open a connection to the specified address and send a Template:Packet with intent set to 3 (Transfer). If the server chooses to accept the transfer, the usual login process will follow.

Cookies previously stored are preserved between server transfers.

Template:Packet header
Field Name		Field Type		Notes
Host		Template:Type (32767)		The hostname or IP of the server.
Port		Template:Type		The port of the server.

Update Tags

Template:Packet header
Field Name		Field Type		Notes
Tagged Registries	Registry	Template:Type	Template:Type	Registry identifier, such as minecraft:block.
	Tags		Template:Type of Tag	Array of tags defined for the registry, each containing a sub-array of entries that have the tag (see below).

Each tag looks like:

Field Name	Field Type	Notes
Tag Name	Template:Type	Name of the tag without the #-prefix, such as minecraft:climbable.
Entries	Template:Type of Template:Type	Numeric IDs of the given type (block, item, etc.). This list replaces the previous list of IDs for the given tag.

See Tag for more information, including a list of vanilla tags.

Due to Template:Bug, any tags that were defined in built-in registries in previous game sessions of a client process will be present by default in new sessions, unless overridden by the server. This occurs on a per-tag basis, so defining a specific tag in a registry will not cause any other tags in that registry to be overridden.

If the server sends Template:Packet without sending any Template:Packet packets during the configuration phase, previously specified tags in synchronized registries will also be retained unless respecified on a per-tag basis. The server must have already sent registries during a previous configuration phase. Note that it is also possible to update tags in play state, so entering configuration is not necessary to do this.

If any Registry Data packets are sent during reconfiguration, all previous tags in all synchronized registries are forgotten, as are the registries themselves.

When used in play state, this packet always only replaces the tags mentioned in the packet. Other tags, including ones belonging to the registries mentioned in the packet, are unaffected.

Custom Report Details

Contains a list of key-value text entries that are included in any crash or disconnection report generated during connection to the server.

Template:Packet header
Field Name		Field Type		Notes
Details	Title	Template:Type (32)	Template:Type (128)
	Description		Template:Type (4096)

Server Links

This packet contains a list of links that the vanilla client will display in the menu available from the pause menu. Link labels can be built-in or custom (i.e., any text).

Template:Packet header
Field Name		Field Type		Notes
Links	Label	Template:Type	Template:Type Template:Type Template:Type or Template:Type	Enums are used for built-in labels (see below), and text components for custom labels.
	URL		Template:Type	Valid URL.

ID	Name	Notes
0	Bug Report	Displayed on connection error screen; included as a comment in the disconnection report.
1	Community Guidelines
2	Support
3	Status
4	Feedback
5	Community
6	Website
7	Forums
8	News
9	Announcements

Clear Dialog

If we're currently in a dialog screen, then this removes the current screen and switches back to the previous one.

Template:Packet header
Field Name	Field Type	Notes
no fields

Serverbound

Client Information

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

Template:Packet header
Field Name	Field Type	Notes
Locale	Template:Type (16)	e.g. en_GB.
View Distance	Template:Type	Client-side render distance, in chunks.
Chat Mode	Template:Type Template:Type	0: enabled, 1: commands only, 2: hidden. See Minecraft:Java Edition protocol/Chat#Client chat mode for more information.
Chat Colors	Template:Type	“Colors” multiplayer setting. The vanilla server stores this value but does nothing with it (see Template:Bug). Some third-party servers disable all coloring in chat and system messages when it is false.
Displayed Skin Parts	Template:Type	Bit mask, see below.
Main Hand	Template:Type Template:Type	0: Left, 1: Right.
Enable text filtering	Template:Type	Enables filtering of text on signs and written book titles. The vanilla client sets this according to the profanityFilterPreferences.profanityFilterOn account attribute indicated by the Mojang API endpoint for player attributes. In offline mode, it is always false.
Allow server listings	Template:Type	Servers usually list online players; this option should let you not show up in that list.
Particle Status	Template:Type Template:Type	0: all, 1: decreased, 2: minimal

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.

Plugin Message (serverbound)

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/

Template:Packet header
Field Name	Field Type	Notes
Channel	Template:Type	Name of the plugin channel used to send the data.
Data	Varies	Any data, depending on the channel. Typically this would be a sequence of fields using standard data types, but some unofficial channels have unusual formats. There is no length prefix that applies to all channel types, but the format specific to the channel may or may not include one or more length prefixes (such as the string length prefix in the standard minecraft:brand channel). The vanilla server enforces a length limit of 32767 bytes on this data, but only if the channel type is unrecognized.

Keep Alive (serverbound)

The server will frequently send out a keep-alive (see Template:Packet), each containing a random ID. The client must respond with the same packet.

Template:Packet header
Field Name	Field Type	Notes
Keep Alive ID	Template:Type

Pong

Response to the clientbound packet (Template:Packet) with the same id.

Template:Packet header
Field Name	Field Type	Notes
ID	Template:Type

Resource Pack Response

Template:Packet header
Field Name	Field Type	Notes
UUID	Template:Type	The unique identifier of the resource pack received in the Template:Packet request.
Result	Template:Type Template:Type	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

Custom Click Action

Sent when the client clicks a Template:Type with the minecraft:custom click action. This is meant as an alternative to running a command, but will not have any effect on vanilla servers.

Template:Packet header
Field Name	Field Type	Notes
ID	Template:Type	The identifier for the click action.
Payload size	Template:Type	The number of bytes in the payload
Payload	Template:Type	The data to send with the click action. May be a TAG_END (0).

Configuration

Clientbound

Finish Configuration

Sent by the server to notify the client that the configuration process has finished. The client validates the registry and tag data received from the server, and answers with Template:Packet whenever it is ready to continue.

Template:Packet header
Field Name	Field Type	Notes
no fields

This packet switches the connection state to play.

Reset Chat

Template:Packet header
Field Name	Field Type	Notes
no fields

Registry Data

Sent by the server to inform the client of the contents of synchronized registries, which are sourced from the server's Minecraft:data packs. Each packet contains the contents of a single registry. The client will accumulate the data contained in these packets during the configuration phase, and validate it once Template:Packet is received from the server.

Template:Packet header
Field Name		Field Type		Notes
Registry ID		Template:Type		Name of the registry, such as minecraft:dimension_type.
Entries	Entry ID	Template:Type	Template:Type	Name of the entry, such as minecraft:overworld.
	Data		Template:Type Template:Type	Entry data. If omitted, sourced from the selected known packs.

The ordering of the entries in the Entries array defines the numeric IDs that they will be assigned to, starting from 0 and counting upwards. It is essential to maintain consistency between server and client, since many parts of the protocol reference these entries by their ID. The client will disconnect upon receiving a reference to a non-existing entry.

The NBT data of registry entries has the same structure as their definitions in Minecraft:data packs, but represented in NBT instead of JSON. The format for each registry is defined in Minecraft:Java Edition protocol/Registries#List of synchronized registries.

Feature Flags

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

Template:Packet header
Field Name	Field Type	Notes
Feature Flags	Template:Type of Template:Type

There is one special feature flag, which is in most versions:

• minecraft:vanilla - enables vanilla features

For the other feature flags, which may change between versions, see Minecraft:Experiments#Java Edition.

Known Packs (clientbound)

Informs the client of which data packs are present on the server. The client is expected to respond with its own Template:Packet packet containing the subset of packs also known to the client, in the same order as they were listed by the server. The vanilla server does not continue with Configuration until it receives a response.

Template:Packet header
Field Name		Field Type		Notes
Known Packs	Namespace	Template:Type	Template:Type (32767)	Namespace part of the name of the pack, such as minecraft.
	ID		Template:Type (32767)	Pathname part of the name of the pack, such as core.
	Version		Template:Type (32767)	Version of the pack. For minecraft:core this corresponds to Minecraft version numbers, such as 1.21.10. Note that the vanilla data pack can change without a protocol version bump, and even a completely vanilla server talking to a vanilla client may fall back to sending all registry data over the wire, if the two are on different protocol-compatible patch versions.

Show Dialog (configuration)

Show a custom dialog screen to the client.

Template:Packet header
Field Name	Field Type	Notes
Dialog	Template:Type	Inline definition as described at Minecraft:Dialog#Dialog format.

Code of Conduct

Show the client the server Code of Conduct. Server will not continue with the configuration stage until the client has accepted the Code of Conduct via the Template:Packet packet.

Template:Packet header
Field Name	Field Type	Notes
Code of Conduct	Template:Type	Code of Conduct of the server.

Serverbound

Acknowledge Finish Configuration

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

Template:Packet header
Field Name	Field Type	Notes
no fields

This packet switches the connection state to play.

Known Packs (serverbound)

Informs the server of which of the data packs it knows are also present on the client. The client sends this in response to Template:Packet.

If the client specifies a pack in this packet, the server may omit its contained NBT data (but not entry listings) from the Template:Packet packet.

Template:Packet header
Field Name		Field Type		Notes
Known Packs	Namespace	Template:Type	Template:Type (32767)	Namespace part of the name of the pack, such as minecraft.
	ID		Template:Type (32767)	Pathname part of the name of the pack, such as core.
	Version		Template:Type (32767)	Version of the pack. For minecraft:core this corresponds to Minecraft version numbers, such as 1.21.10. Note that the vanilla data pack can change without a protocol version bump, and even a completely vanilla server talking to a vanilla client may fall back to sending all registry data over the wire, if the two are on different protocol-compatible patch versions.

Accept Code of Conduct

Sent when the client clicks on the "Acknowledge" field in the "Code of Conduct" view. Sent in response to the Template:Packet packet.

Template:Packet header
Field Name	Field Type	Notes
no fields

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.

As of 1.20.6, the vanilla server only uses this to ensure Template:Packet and associated packets used to configure the entity happen on the same tick. Each entity gets a separate bundle.

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

Template:Packet header
Field Name	Field Type	Notes
no fields

Spawn Entity

Sent by the server to create an entity on the client, normally upon the entity spawning within or entering the player's view range.

The local player entity is automatically created by the client, and must not be created explicitly using this packet. Doing so on the vanilla client will have strange consequences.

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type	A unique integer ID mostly used in the protocol to identify the entity. If an entity with the same ID already exists on the client, it is automatically deleted and replaced by the new entity. On the vanilla server entity IDs are globally unique across all dimensions and never reused while the server is running, but not preserved across server restarts.
Entity UUID	Template:Type	A unique identifier that is mostly used in persistence and places where the uniqueness matters more. It is possible to create multiple entities with the same UUID on the vanilla client, but a warning will be logged, and functionality dependent on UUIDs may ignore the entity or otherwise misbehave.
Type	Template:Type	ID in the minecraft:entity_type registry (see "type" field in Minecraft:Java Edition protocol/Entity metadata#Entities).
X	Template:Type
Y	Template:Type
Z	Template:Type
Velocity	Template:Type
Pitch	Template:Type
Yaw	Template:Type
Head Yaw	Template:Type	Only used by living entities, where the head of the entity may differ from the general body rotation.
Data	Template:Type	Meaning dependent on the value of the Type field, see Minecraft:Java Edition protocol/Object data for details.

Template:Warning When in online mode, the UUIDs must be valid and have valid skin blobs. In offline mode, the vanilla server uses UUID v3 and chooses the player's UUID by using the String OfflinePlayer:<player name>, encoding it in UTF-8 (and case-sensitive), then processes it with UUID.nameUUIDFromBytes.

For NPCs UUID v2 should be used. Note:

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

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

Entity Animation

Sent whenever an entity should change animation.

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type	Player ID.
Animation	Template:Type	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 Template:Packet (id 1). Will only send the changed values if previously requested.

Template:Packet header
Field Name		Field Type		Notes
Statistics	Category ID	Template:Type	Template:Type	ID in the minecraft:stat_type registry; see below.
	Statistic ID		Template:Type	See below.
	Value		Template:Type	The amount to set it to.

Categories (defined in the minecraft:stat_type registry).

Name	ID	Registry
minecraft:mined	0	minecraft:block
minecraft:crafted	1	minecraft:item
minecraft:used	2	minecraft:item
minecraft:broken	3	minecraft:item
minecraft:picked_up	4	minecraft:item
minecraft:dropped	5	minecraft:item
minecraft:killed	6	minecraft:entity_type
minecraft:killed_by	7	minecraft:entity_type
minecraft:custom	8	minecraft:custom_stat

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

Custom uses IDs in the minecraft:custom_stat registry:

Name	ID	Unit
minecraft:leave_game	0	None
minecraft:play_time	1	Time
minecraft:total_world_time	2	Time
minecraft:time_since_death	3	Time
minecraft:time_since_rest	4	Time
minecraft:sneak_time	5	Time
minecraft:walk_one_cm	6	Distance
minecraft:crouch_one_cm	7	Distance
minecraft:sprint_one_cm	8	Distance
minecraft:walk_on_water_one_cm	9	Distance
minecraft:fall_one_cm	10	Distance
minecraft:climb_one_cm	11	Distance
minecraft:fly_one_cm	12	Distance
minecraft:walk_under_water_one_cm	13	Distance
minecraft:minecart_one_cm	14	Distance
minecraft:boat_one_cm	15	Distance
minecraft:pig_one_cm	16	Distance
minecraft:happy_ghast_one_cm	17	Distance
minecraft:horse_one_cm	18	Distance
minecraft:aviate_one_cm	19	Distance
minecraft:swim_one_cm	20	Distance
minecraft:strider_one_cm	21	Distance
minecraft:jump	22	None
minecraft:drop	23	None
minecraft:damage_dealt	24	Damage
minecraft:damage_dealt_absorbed	25	Damage
minecraft:damage_dealt_resisted	26	Damage
minecraft:damage_taken	27	Damage
minecraft:damage_blocked_by_shield	28	Damage
minecraft:damage_absorbed	29	Damage
minecraft:damage_resisted	30	Damage
minecraft:deaths	31	None
minecraft:mob_kills	32	None
minecraft:animals_bred	33	None
minecraft:player_kills	34	None
minecraft:fish_caught	35	None
minecraft:talked_to_villager	36	None
minecraft:traded_with_villager	37	None
minecraft:eat_cake_slice	38	None
minecraft:fill_cauldron	39	None
minecraft:use_cauldron	40	None
minecraft:clean_armor	41	None
minecraft:clean_banner	42	None
minecraft:clean_shulker_box	43	None
minecraft:interact_with_brewingstand	44	None
minecraft:interact_with_beacon	45	None
minecraft:inspect_dropper	46	None
minecraft:inspect_hopper	47	None
minecraft:inspect_dispenser	48	None
minecraft:play_noteblock	49	None
minecraft:tune_noteblock	50	None
minecraft:pot_flower	51	None
minecraft:trigger_trapped_chest	52	None
minecraft:open_enderchest	53	None
minecraft:enchant_item	54	None
minecraft:play_record	55	None
minecraft:interact_with_furnace	56	None
minecraft:interact_with_crafting_table	57	None
minecraft:open_chest	58	None
minecraft:sleep_in_bed	59	None
minecraft:open_shulker_box	60	None
minecraft:open_barrel	61	None
minecraft:interact_with_blast_furnace	62	None
minecraft:interact_with_smoker	63	None
minecraft:interact_with_lectern	64	None
minecraft:interact_with_campfire	65	None
minecraft:interact_with_cartography_table	66	None
minecraft:interact_with_loom	67	None
minecraft:interact_with_stonecutter	68	None
minecraft:bell_ring	69	None
minecraft:raid_trigger	70	None
minecraft:raid_win	71	None
minecraft:interact_with_anvil	72	None
minecraft:interact_with_grindstone	73	None
minecraft:target_hit	74	None
minecraft:interact_with_smithing_table	75	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.

Template:Packet header
Field Name	Field Type	Notes
Sequence ID	Template:Type	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.

When removing the break animation, you must use the ID of the entity that set it.

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type	The ID of the entity breaking the block.
Location	Template:Type	Block Position.
Destroy Stage	Template:Type	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.

Template:Packet header
Field Name	Field Type	Notes
Location	Template:Type
Type	Template:Type	ID in the minecraft:block_entity_type registry
NBT Data	Template:Type	Data to set.

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 Minecraft:Java Edition protocol/Block actions for a list of values.

Template:Packet header
Field Name	Field Type	Notes
Location	Template:Type	Block coordinates.
Action ID (Byte 1)	Template:Type	Varies depending on block — see Minecraft:Java Edition protocol/Block actions.
Action Parameter (Byte 2)	Template:Type	Varies depending on block — see Minecraft:Java Edition protocol/Block actions.
Block Type	Template:Type	ID in the minecraft:block registry. This value is unused by the vanilla 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.

Template:Packet header
Field Name	Field Type	Notes
Location	Template:Type	Block Coordinates.
Block ID	Template:Type	The new block state ID for the block as given in the global block state palette.

Boss Bar

Template:Packet header
Field Name		Field Type	Notes
UUID		Template:Type	Unique ID for this bar.
Action		Template:Type Template:Type	Determines the layout of the remaining packet.
Action	Field Name
0: add	Title	Template:Type
	Health	Template:Type	From 0 to 1. Values greater than 1 do not crash a vanilla client, and start rendering part of a second health bar at around 1.5.
	Color	Template:Type Template:Type	Color ID (see below).
	Division	Template:Type Template:Type	Type of division (see below).
	Flags	Template:Type	Bit mask. 0x01: should darken sky, 0x02: 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	Template:Type	as above
3: update title	Title	Template:Type
4: update style	Color	Template:Type Template:Type	Color ID (see below).
	Dividers	Template:Type Template:Type	as above
5: update flags	Flags	Template:Type	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

Template:Packet header
Field Name	Field Type	Notes
Difficulty	Template:Type Template:Type	0: peaceful, 1: easy, 2: normal, 3: hard.
Difficulty locked?	Template:Type

Chunk Batch Finished

Marks the end of a chunk batch. The vanilla client marks the time it receives this packet and calculates the elapsed duration since the beginning of the chunk batch. The client 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 Template:Packet. 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 vanilla client uses the samples from the latest 15 batches to estimate the milliseconds per chunk number.

Template:Packet header
Field Name	Field Type	Notes
Batch size	Template:Type	Number of chunks.

Chunk Batch Start

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

Template:Packet header
Field Name	Field Type	Notes
no fields

Chunk Biomes

Template:Packet header
Field Name		Field Type		Notes
Chunk biome data	Chunk Z	Template:Type	Template:Type	Chunk coordinate (block coordinate divided by 16, rounded down)
	Chunk X		Template:Type	Chunk coordinate (block coordinate divided by 16, rounded down)
	Data		Template:Type of Template:Type	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 Template:Type, with Z being the upper 32 bits.

Clear Titles

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

Template:Packet header
Field Name	Field Type	Notes
Reset	Template:Type

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.

Template:Packet header
Field Name		Field Type		Notes
ID		Template:Type		Transaction ID.
Start		Template:Type		Start of the text to replace.
Length		Template:Type		Length of the text to replace.
Matches	Match	Template:Type	Template:Type (32767)	One eligible value to insert, note that each command is sent separately instead of in a single string, hence the need for Count.
	Tooltip		Template:Type Template:Type	Tooltip to display.

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.

Template:Packet header
Field Name	Field Type	Notes
Nodes	Template:Type of Node	An array of nodes.
Root index	Template:Type	Index of the root node in the previous array.

For more information on this packet, see the Minecraft:Java Edition protocol/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 vanilla client disregards the provided window ID and closes any active window.

Template:Packet header
Field Name	Field Type	Notes
Window ID	Template:Type	This is the ID of the window that was closed. 0 for inventory.

Set Container Content

File:Inventory-slots.png

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).

Template:Packet header
Field Name	Field Type	Notes
Window ID	Template:Type	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 vanilla server does not appear to utilize this special case.)
State ID	Template:Type	A server-managed sequence number used to avoid desynchronization; see #Click Container.
Slot Data	Template:Type of Template:Type
Carried Item	Template:Type	Item being dragged with the mouse.

See inventory windows for further information about how slots are indexed. Use Template:Packet 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.

Template:Packet header
Field Name	Field Type	Notes
Window ID	Template:Type
Property	Template:Type	The property to be updated, see below.
Value	Template:Type	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 vanilla 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.
Smithing Table	0: Has recipe error	True if greater than zero.
Crafter	0-9: Slot Disabled	0 If the slot is enabled, 1 if the slot is disabled

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:swift_sneak	Swift Sneak
13	minecraft:sharpness	Sharpness
14	minecraft:smite	Smite
15	minecraft:bane_of_arthropods	Bane of Arthropods
16	minecraft:knockback	Knockback
17	minecraft:fire_aspect	Fire Aspect
18	minecraft:looting	Looting
19	minecraft:sweeping_edge	Sweeping Edge
20	minecraft:efficiency	Efficiency
21	minecraft:silk_touch	Silk Touch
22	minecraft:unbreaking	Unbreaking
23	minecraft:fortune	Fortune
24	minecraft:power	Power
25	minecraft:punch	Punch
26	minecraft:flame	Flame
27	minecraft:infinity	Infinity
28	minecraft:luck_of_the_sea	Luck of the Sea
29	minecraft:lure	Lure
30	minecraft:loyalty	Loyalty
31	minecraft:impaling	Impaling
32	minecraft:riptide	Riptide
33	minecraft:channeling	Channeling
34	minecraft:multishot	Multishot
35	minecraft:quick_charge	Quick Charge
36	minecraft:piercing	Piercing
37	minecraft:density	Density
38	minecraft:breach	Breach
39	minecraft:wind_burst	Wind Burst
40	minecraft:mending	Mending
41	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.

Template:Packet header
Field Name	Field Type	Notes
Window ID	Template:Type	The window that 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	Template:Type	A server-managed sequence number used to avoid desynchronization; see #Click Container.
Slot	Template:Type	The slot that should be updated.
Slot Data	Template:Type

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 vanilla 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 vanilla server does not handle this restriction in any way, leading to MC-242392.)

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 vanilla 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).

Template:Packet header
Field Name	Field Type	Notes
Cooldown Group	Template:Type	Identifier of the item (minecraft:stone) or the cooldown group ("use_cooldown" item component)
Cooldown Ticks	Template:Type	Number of ticks to apply a cooldown for, or 0 to clear the cooldown.

Chat Suggestions

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

Template:Packet header
Field Name	Field Type	Notes
Action	Template:Type Template:Type	0: Add, 1: Remove, 2: Set
Entries	Template:Type of Template:Type (32767)

Damage Event

Template:Packet header
Field Name		Field Type		Notes
Entity ID		Template:Type		The ID of the entity taking damage
Source Type ID		Template:Type		The type of damage in the minecraft:damage_type registry, defined by the Template:Packet packet.
Source Cause ID		Template:Type		The ID + 1 of the entity responsible for the damage, if present. If not present, the value is 0
Source Direct ID		Template:Type		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 directly, such as by manually attacking, this field will contain the same value as Source Cause ID.
Source Position	X	Template:Type	Template:Type	The vanilla server sends the Source Position when the damage was dealt by the /damage command and a position was specified
	Y		Template:Type
	Z		Template:Type

Debug Block Value

Template:Packet header
Field Name	Field Type	Notes
Location	Template:Type
Update	Template:Type

Debug Chunk Value

Template:Packet header
Field Name	Field Type	Notes
Chunk Z	Template:Type
Chunk X	Template:Type
Update	Template:Type

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

Debug Entity Value

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type
Update	Template:Type

Debug Event

Template:Packet header
Field Name	Field Type	Notes
Event	Template:Type

Debug Sample

Sample data that is sent periodically after the client has subscribed with Template:Packet.

The vanilla server only sends debug samples to players who are server operators.

Template:Packet header
Field Name	Field Type	Notes
Sample	Template:Type of Template:Type	Array of type-dependent samples.
Sample Type	Template:Type Template:Type	See below.

Types:

Id	Name	Description
0	Tick time	Four different tick-related metrics, each one represented by one long on the array. They are measured in nano-seconds, and are as follows: 0: Full tick time: Aggregate of the three times below; 1: Server tick time: Main server tick logic; 2: Tasks time: Tasks scheduled to execute after the main logic; 3: Idle time: Time idling to complete the full 50ms tick cycle. Note that the vanilla client calculates the timings used for min/max/average display by subtracting the idle time from the full tick time. This can cause the displayed values to go negative if the idle time is (nonsensically) greater than the full tick time.

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.

Template:Packet header
Field Name	Field Type	Notes
Message ID	Template:Type	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	Template:Type Template:Type (256)	The previous message's signature. Always 256 bytes and not length-prefixed.

Disguised Chat Message

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

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

Template:Packet header
Field Name	Field Type	Notes
Message	Template:Type	This is used as the content parameter when formatting the message on the client.
Chat Type	Template:Type Template:Type	Either the type of chat in the minecraft:chat_type registry, defined by the Template:Packet packet, or an inline definition.
Sender Name	Template:Type	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.
Target Name	Template:Type Template:Type	The name of the one receiving the message, usually the receiver's display name. 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).

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type
Entity Status	Template:Type Template:Type	See Minecraft:Java Edition protocol/Entity statuses for a list of which statuses are valid for each type of entity.

Teleport Entity

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

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type
X	Template:Type
Y	Template:Type
Z	Template:Type
Velocity X	Template:Type
Velocity Y	Template:Type
Velocity Z	Template:Type
Yaw	Template:Type	Rotation on the X axis, in degrees.
Pitch	Template:Type	Rotation on the Y axis, in degrees.
On Ground	Template:Type

Explosion

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

Template:Packet header
Field Name		Field Type		Notes
X		Template:Type
Y		Template:Type
Z		Template:Type
Radius		Template:Type
Block Count		Template:Type
Player Delta Velocity	X	Template:Type	Template:Type	Velocity difference of the player being pushed by the explosion.
	Y		Template:Type
	Z		Template:Type
Explosion Particle ID		Template:Type		ID in the minecraft:particle_type registry.
Explosion Particle Data		Varies		Particle data as specified in Minecraft:Java Edition protocol/Particles.
Explosion Sound		Template:Type Template:Type		ID in the minecraft:sound_event registry, or an inline definition.
Block Particle Alternatives	Particle ID	Template:Type	Template:Type
	Particle Data		Varies	Particle data as specified in Minecraft:Java Edition protocol/Particles.
	Scaling		Template:Type
	Speed		Template:Type
	Weight		Template:Type

Unload Chunk

Tells the client to unload a chunk column.

Template:Packet header
Field Name	Field Type	Notes
Chunk Z	Template:Type	Block coordinate divided by 16, rounded down.
Chunk X	Template:Type	Block coordinate divided by 16, rounded down.

Note: The order is inverted, because the client reads this packet as one big-endian Template:Type, 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, such as weather, respawn availability (from Minecraft:bed and Minecraft:respawn anchor), game mode, some game rules, and Minecraft:demo messages.

Template:Packet header
Field Name	Field Type	Notes
Event	Template:Type	See below.
Value	Template:Type	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	Begin raining
2	End 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 vanilla 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 vanilla 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).

Game Rule Values

Template:Packet header
Field Name		Field Type		Notes
Rules	Name	Template:Type	Template:Type
	Value		Template:Type (32767)

Game Test Highlight Position

Template:Packet header
Field Name	Field Type	Notes
Absolute Location	Template:Type
Relative Location	Template:Type

Open Horse Screen

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

Template:Packet header
Field Name	Field Type	Notes
Window ID	Template:Type	Same as the field of Template:Packet.
Inventory columns count	Template:Type	How many columns of horse inventory slots exist in the GUI, 3 slots per column.
Entity ID	Template:Type	The "owner" entity of the GUI. The client should close the GUI if the owner entity dies or is cleared.

Hurt Animation

Plays a bobbing animation for the entity receiving damage.

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type	The ID of the entity taking damage
Yaw	Template:Type	The direction the damage is coming from in relation to the entity

Initialize World Border

Template:Packet header
Field Name	Field Type	Notes
Center X	Template:Type
Center Z	Template:Type
Old Diameter	Template:Type	Current length of a single side of the world border, in meters.
New Diameter	Template:Type	Target length of a single side of the world border, in meters.
Speed	Template:Type	Number of real-time milliseconds until New Diameter is reached. It appears that vanilla 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	Template:Type	Resulting coordinates from a portal teleport are limited to ±value. Usually 29999984.
Warning Blocks	Template:Type	In meters.
Warning Time	Template:Type	In seconds as set by /worldborder warning time.

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

<syntaxhighlight lang="java"> distance = max(min(resizeSpeed * 1000 * warningTime, abs(targetDiameter - currentDiameter)), warningDistance); if (playerDistance < distance) {

   warning = 1.0 - playerDistance / distance;

} else {

   warning = 0.0;

} </syntaxhighlight>

Chunk Data and Update Light

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 Template:Packet; 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 Template:Packet later.

Template:Packet header
Field Name		Field Type		Notes
Chunk X		Template:Type		Chunk coordinate (block coordinate divided by 16, rounded down)
Chunk Z		Template:Type		Chunk coordinate (block coordinate divided by 16, rounded down)
Heightmaps		Template:Type of Heightmap		See Chunk Format#Heightmap structure
Data		Template:Type of Template:Type		See Chunk Format#Data structure
Block Entities	Packed XZ	Template:Type	Template:Type	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		Template:Type	The height relative to the world
	Type		Template:Type	The type of block entity
	Data		NBT	The block entity's data, without the X, Y, and Z values
Light	Template:Type

Unlike the Template:Packet 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.

Template:Packet header
Field Name	Field Type	Notes
Event	Template:Type	The event, see below.
Location	Template:Type	The location of the event.
Data	Template:Type	Extra data for certain events, see below.
Disable Relative Volume	Template:Type	See above.

Events:

ID	Name	Data
Sound
1000	Dispenser dispenses
1001	Dispenser fails to dispense
1002	Dispenser shoots
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	Ender dragon shoots
1018	Blaze shoots
1019	Zombie attacks wooden door
1020	Zombie attacks iron door
1021	Zombie breaks wooden 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 dies
1029	Anvil destroyed
1030	Anvil used
1031	Anvil lands
1032	Portal travel
1033	Chorus flower grows
1034	Chorus flower dies
1035	Brewing stand brews
1038	End portal created
1039	Phantom bites
1040	Zombie converts to drowned
1041	Husk converts to zombie by drowning
1042	Grindstone used
1043	Book page turned
1044	Smithing table used
1045	Pointed dripstone landing
1046	Lava dripping on cauldron from dripstone
1047	Water dripping on cauldron from dripstone
1048	Skeleton converts to stray
1049	Crafter successfully crafts item
1050	Crafter fails to craft item
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 in end portal frame
1504	Fluid drips from dripstone
1505	Bone meal particles and sound	How many particles to spawn.
2000	Dispenser activation smoke	Direction, see below.
2001	Block break + block break sound	Block state ID from the global block state palette.
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	Spawner spawns mob: smoke + flames
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
2010	Crafter activation smoke	Direction, see below.
2011	Bee fertilizes plant	How many particles to spawn.
2012	Turtle egg placed	How many particles to spawn.
2013	Smash attack (mace)	How many particles to spawn.
3000	End gateway spawns
3001	Ender dragon resurrected
3002	Electric spark
3003	Copper apply wax
3004	Copper remove wax
3005	Copper scrape oxidation
3006	Sculk charge
3007	Sculk shrieker shriek
3008	Block finished brushing	Block state ID from the global block state palette.
3009	Sniffer egg cracks	If 1, 3-6, if any other number, 1-3 particles will be spawned.
3011	Trial spawner spawns mob (at spawner)
3012	Trial spawner spawns mob (at spawn location)
3013	Trial spawner detects player	Number of players nearby
3014	Trial spawner ejects item
3015	Vault activates
3016	Vault deactivates
3017	Vault ejects item
3018	Cobweb weaved
3019	Ominous trial spawner detects player	Number of players nearby
3020	Trial spawner turns ominous	If 0, the sound will be played at 0.3 volume. Otherwise, it is played at full volume.
3021	Ominous item spawner spawns item

Smoke directions:

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

Particle

Displays the named particle

Template:Packet header
Field Name	Field Type	Notes
Long Distance	Template:Type	If true, particle distance increases from 256 to 65536.
Always Visible	Template:Type	Whether this particle should always be visible.
X	Template:Type	X position of the particle.
Y	Template:Type	Y position of the particle.
Z	Template:Type	Z position of the particle.
Offset X	Template:Type	This is added to the X position after being multiplied by random.nextGaussian().
Offset Y	Template:Type	This is added to the Y position after being multiplied by random.nextGaussian().
Offset Z	Template:Type	This is added to the Z position after being multiplied by random.nextGaussian().
Max Speed	Template:Type
Particle Count	Template:Type	The number of particles to create.
Particle ID	Template:Type	ID in the minecraft:particle_type registry.
Data	Varies	Particle data as specified in Minecraft:Java Edition protocol/Particles.

Update Light

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

Template:Packet header
Field Name	Field Type	Notes
Chunk X	Template:Type	Chunk coordinate (block coordinate divided by 16, rounded down)
Chunk Z	Template:Type	Chunk coordinate (block coordinate divided by 16, rounded down)
Data	Template:Type

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)

See Minecraft:protocol encryption for information on logging in.

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type	The player's Entity ID (EID).
Is hardcore	Template:Type
Dimension Names	Template:Type of Template:Type	Identifiers for all dimensions on the server.
Max Players	Template:Type	Was once used by the client to draw the tab list, but now it is ignored.
View Distance	Template:Type	Render distance (2-32).
Simulation Distance	Template:Type	Server simulation distance. See Template:Packet.
Reduced Debug Info	Template:Type	If true, a vanilla client shows reduced information on the Minecraft:debug screen. For servers in development, this should almost always be false.
Enable respawn screen	Template:Type	Set to false when the doImmediateRespawn gamerule is true.
Do limited crafting	Template:Type	Whether players can only craft recipes they have already unlocked. Currently unused by the client.
Dimension Type	Template:Type	The ID of the type of dimension in the minecraft:dimension_type registry, defined by the Registry Data packet.
Dimension Name	Template:Type	Name of the dimension being spawned into.
Hashed seed	Template:Type	First 8 bytes of the SHA-256 hash of the world's seed. Used client-side for biome noise
Game mode	Template:Type	0: Survival, 1: Creative, 2: Adventure, 3: Spectator.
Previous Game mode	Template:Type	-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	Template:Type	True if the world is a Minecraft:debug mode world; debug mode worlds cannot be modified and have predefined blocks.
Is Flat	Template:Type	True if the world is a Minecraft:superflat world; flat worlds have different void fog and a horizon at Y=0 instead of Y=63.
Has death location	Template:Type	If true, then the next two fields are present.
Death dimension name	Template:Type Template:Type	Name of the dimension the player died in.
Death location	Template:Type Template:Type	The location that the player died at.
Portal cooldown	Template:Type	The number of ticks until the player can use the last used portal again. Looks like it's an attempt to fix MC-180.
Sea level	Template:Type
Online mode	Template:Type
Enforces Secure Chat	Template:Type

Low Disk Space Warning

Template:Packet header
Field Name	Field Type	Notes
no fields

Map Data

Updates a rectangular area on a Minecraft:map item.

Template:Packet header
Field Name		Field Type		Notes
Map ID		Template:Type		Map ID of the map being modified
Scale		Template:Type		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		Template:Type		True if the map has been locked in a cartography table
Icons	Type	Template:Type Template:Type	Template:Type Template:Type	See below
	X		Template:Type	Map coordinates: -128 for furthest left, +127 for furthest right
	Z		Template:Type	Map coordinates: -128 for highest, +127 for lowest
	Direction		Template:Type	0-15
	Display Name		Template:Type Template:Type
Color Patch	Columns	Template:Type		Number of columns updated
	Rows	Template:Type Template:Type		Only if Columns is more than 0; number of rows updated
	X	Template:Type Template:Type		Only if Columns is more than 0; x offset of the westernmost column
	Z	Template:Type Template:Type		Only if Columns is more than 0; z offset of the northernmost row
	Data	Template:Type Template:Type of Template:Type		Only if Columns is more than 0; see Minecraft: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	Monument
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
27	Desert Village
28	Plains Village
29	Savanna Village
30	Snowy Village
31	Taiga Village
32	Jungle Temple
33	Swamp Hut
34	Trial Chambers

Merchant Offers

The list of trades a villager NPC is offering.

Template:Packet header
Field Name		Field Type		Notes
Window ID		Template:Type		The ID of the window that is open; this is an int rather than a byte.
Trades	Input item 1	Template:Type	Trade Item	See below. 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		Template:Type	The item the player will receive from this villager trade.
	Input item 2		Template:Type Trade Item	The second item the player has to supply for this villager trade.
	Trade disabled		Template:Type	True if the trade is disabled; false if the trade is enabled.
	Number of trade uses		Template:Type	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		Template:Type	Number of times this trade can be used before it's exhausted.
	XP		Template:Type	Amount of XP the villager will earn each time the trade is used.
	Special Price		Template:Type	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		Template:Type	Can be low (0.05) or high (0.2). Determines how much demand, player reputation, and temporary effects will adjust the price.
	Demand		Template:Type	If positive, causes the price to increase. Negative values seem to be treated the same as zero.
Villager level		Template:Type		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		Template:Type		Total experience for this villager (always 0 for the wandering trader).
Is regular villager		Template:Type		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		Template:Type		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.

Trade Item:

Field Name		Field Type		Meaning
Item ID		Template:Type		The item ID. Item IDs are distinct from block IDs; see Data Generators for more information.
Item Count		Template:Type		The item count.
Components	Component type	Template:Type	Template:Type Template:Type	The type of component. See Structured components for more detail.
	Component data		Varies	The component-dependent data. See Structured components for more detail.

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 number 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

File:1.14-merchant-slots.png

The merchant UI, for reference

Update Entity Position

This packet is sent by the server when an entity moves a small distance. The change in position is represented as a fixed-point number with 12 fraction bits and 4 integer bits. As such, the maximum movement distance along each axis is 8 blocks in the negative direction, or 7.999755859375 blocks in the positive direction. If the movement exceeds these limits, Template:Packet should be sent instead.

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type
Delta X	Template:Type	Change in X position as currentX * 4096 - prevX * 4096.
Delta Y	Template:Type	Change in Y position as currentY * 4096 - prevY * 4096.
Delta Z	Template:Type	Change in Z position as currentZ * 4096 - prevZ * 4096.
On Ground	Template:Type

Update Entity Position and Rotation

This packet is sent by the server when an entity rotates and moves. See #Update Entity Position for how the position is encoded.

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type
Delta X	Template:Type	Change in X position as currentX * 4096 - prevX * 4096.
Delta Y	Template:Type	Change in Y position as currentY * 4096 - prevY * 4096.
Delta Z	Template:Type	Change in Z position as currentZ * 4096 - prevZ * 4096.
Yaw	Template:Type	New angle, not a delta.
Pitch	Template:Type	New angle, not a delta.
On Ground	Template:Type

Move Minecart Along Track

Template:Packet header
Field Name		Field Type		Notes
Entity ID		Template:Type
Steps	X	Template:Type	Template:Type
	Y		Template:Type
	Z		Template:Type
	Velocity X		Template:Type
	Velocity Y		Template:Type
	Velocity Z		Template:Type
	Yaw		Template:Type
	Pitch		Template:Type
	Weight		Template:Type

Update Entity Rotation

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

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type
Yaw	Template:Type	New angle, not a delta.
Pitch	Template:Type	New angle, not a delta.
On Ground	Template:Type

Move Vehicle (clientbound)

If the player is riding a client-side-controlled vehicle, teleports the vehicle to the specified position. Sent by the vanilla server in response to serverbound Template:Packet packets that fail the movement speed check. Note that all fields use absolute positioning and do not allow for relative positioning.

Template:Packet header
Field Name	Field Type	Notes
X	Template:Type	Absolute position (X coordinate).
Y	Template:Type	Absolute position (Y coordinate).
Z	Template:Type	Absolute position (Z coordinate).
Yaw	Template:Type	Absolute rotation on the vertical axis, in degrees.
Pitch	Template:Type	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.

Template:Packet header
Field Name	Field Type	Notes
Hand	Template:Type Template:Type	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 the 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 Template:Packet.

Template:Packet header
Field Name	Field Type	Notes
Window ID	Template:Type	An identifier for the window to be displayed. The vanilla 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 vanilla server wraps around after 100.
Window Type	Template:Type	The window type to use for display. Contained in the minecraft:menu registry; see Minecraft:Java Edition protocol/Inventory for the different values.
Window Title	Template:Type	The title of the window.

Open Sign Editor

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

Template:Packet header
Field Name	Field Type	Notes
Location	Template:Type
Is Front Text	Template:Type	Whether the opened editor is for the front or on the back of the sign

Place Ghost Recipe

Response to the serverbound packet (Template:Packet), with the same recipe ID. Appears to be used to notify the UI.

Template:Packet header
Field Name	Field Type	Notes
Window ID	Template:Type
Recipe Display	Template:Type

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.

Template:Packet header
Field Name	Field Type	Notes
Flags	Template:Type	Bit field, see below.
Flying Speed	Template:Type	0.05 by default.
Field of View Modifier	Template:Type	Modifies the field of view, like a speed potion. A vanilla server will use the same value as the movement speed sent in the Template:Packet 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

If Flying is set but Allow Flying is unset, the player is unable to stop flying.

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

Template:Packet header
Sector	Field Name		Field Type	Notes
Header	Global Index		Template:Type	A counter that starts at zero and gets increased by one for each chat message sent to the client. Each client has its own counter.
	Sender		Template:Type	Used by the vanilla client for the disableChat launch option. Setting both longs to 0 will always display the message regardless of the setting.
	Index		Template:Type
	Message Signature bytes		Template:Type Template:Type (256)	Cryptography, the signature consists of the Sender UUID, Session UUID from the Template:Packet 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 Template:Wikipedia and signed using the Template:Wikipedia 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		Template:Type (256)	Raw (optionally) signed sent message content. This is used as the content parameter when formatting the message on the client.
	Timestamp		Template:Type	Represents the time the message was signed as milliseconds since the Template:Wikipedia, used to check if the message was received within 2 minutes of it being sent.
	Salt		Template:Type	Cryptography, used for validating the message signature.
Template:Type (20)	Message ID		Template:Type	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		Template:Type Template:Type (256)	The previous message's signature. Contains the same type of data as Message Signature bytes (256 bytes) above. Not length-prefixed.
Other	Unsigned Content		Template:Type Template:Type
	Filter Type		Template:Type Template:Type	If the message has been filtered
	Filter Type Bits		Template:Type Template:Type	Only present if the Filter Type is Partially Filtered. Specifies the indices at which characters in the original message string should be replaced with the # symbol (i.e., filtered) by the vanilla client
Chat Formatting	Chat Type		Template:Type Template:Type	Either the type of chat in the minecraft:chat_type registry, defined by the Template:Packet packet, or an inline definition.
	Sender Name		Template:Type	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.
	Target Name		Template:Type Template:Type	The name of the one receiving the message, usually the receiver's display name. This is used as the target parameter when formatting the message on the client.

File:MinecraftChat.drawio4.png

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 vanilla client. This data was once used for twitch.tv metadata circa 1.8.

Template:Packet header
Field Name	Field Type	Notes
Duration	Template:Type	Length of the combat in ticks.

Enter Combat

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

Template:Packet header
Field Name	Field Type	Notes
no fields

Combat Death

Used to send a respawn screen.

Template:Packet header
Field Name	Field Type	Notes
Player ID	Template:Type	Entity ID of the player that died (should match the client's entity ID).
Message	Template:Type	The death message.

Player Info Remove

Sent by the server to remove players from the client's player list.

Template:Packet header
Field Name	Field Type	Notes
UUIDs	Template:Type of Template:Type	UUIDs of players to remove.

Player Info Update

Sent by the server to add or update players on the client's player list. The player list determines which player names can be tab-completed, player skins (player profiles), player display names and who shows up on the tab list (<tab> in the client).

Template:Packet header
Field Name		Field Type		Notes
Actions		Template:Type		Determines what actions are present.
Players	UUID	Template:Type	Template:Type	The player UUID
	Player Actions		Template:Type 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		Template:Type (16)
		Template:Packet properties	Name	Template:Type (16)	Template:Type (64)
			Value		Template:Type (32767)
			Signature		Template:Type Template:Type (1024)
Initialize Chat	0x02	Data	Chat session ID	Template:Type	Template:Type
			Public key expiry time		Template:Type	Key expiry time, as a UNIX timestamp in milliseconds. Only sent if Has Signature Data is true.
			Encoded public key		Template:Type (512) of Template:Type	The player's public key, in bytes. Only sent if Has Signature Data is true.
			Public key signature		Template:Type (4096) of Template:Type	The public key's digital signature. Only sent if Has Signature Data is true.
Update Game Mode	0x04	Game Mode		Template:Type
Update Listed	0x08	Listed		Template:Type		Whether the player should be listed on the tab list.
Update Latency	0x10	Ping		Template:Type		Measured in milliseconds.
Update Display Name	0x20	Display Name		Template:Type Template:Type		Only sent if Has Display Name is true.
Update List Priority	0x40	Priority		Template:Type		See below.
Update Hat	0x80	Visible		Template:Type		Whether the player's hat skin layer is shown.

The properties included in this packet are the same as in Template:Packet, for the current player.

Ping values correspond with icons in the following way:

• A ping that is 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.

The order of players on the tab list is determined as follows:

• Players with higher priorities are sorted before those with lower priorities.
• Among players of equal priorities, spectators are sorted after non-spectators.
• Within each of those groups, players are sorted into teams. The teams are ordered case-sensitively by team name in ascending order. Players with no team are listed first.
• The players of each team (and non-team) are sorted case-insensitively by name in ascending order.

Look At

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

Template:Packet header
Field Name	Field Type	Notes
Feet/eyes	Template:Type Template:Type	Values are feet=0, eyes=1. If set to eyes, aims using the head position; otherwise, aims using the feet position.
Target x	Template:Type	x coordinate of the point to face towards.
Target y	Template:Type	y coordinate of the point to face towards.
Target z	Template:Type	z coordinate of the point to face towards.
Is entity	Template:Type	If true, additional information about an entity is provided.
Entity ID	Template:Type Template:Type	Only if is entity is true — the entity to face towards.
Entity feet/eyes	Template:Type Template:Type Template:Type	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 Template:Packet packet with an ID matching the one sent in the teleport packet is received. The vanilla client will also send a Template:Packet packet after the Template:Packet packet with the position and rotation received from this packet, and horizontal collision and on ground set to false.

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 (see MC-90097).

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

If the player is riding a vehicle, this packet has no effect, but both the Template:Packet and Template:Packet packets are still sent.

Template:Packet header
Field Name	Field Type	Notes
Teleport ID	Template:Type	Client should confirm this packet with Template:Packet containing the same Teleport ID.
X	Template:Type	Absolute or relative position, depending on Flags.
Y	Template:Type	Absolute or relative position, depending on Flags.
Z	Template:Type	Absolute or relative position, depending on Flags.
Velocity X	Template:Type
Velocity Y	Template:Type
Velocity Z	Template:Type
Yaw	Template:Type	Absolute or relative rotation on the X axis, in degrees.
Pitch	Template:Type	Absolute or relative rotation on the Y axis, in degrees.
Flags	Template:Type

Player Rotation

Template:Packet header
Field Name	Field Type	Notes
Yaw	Template:Type	Rotation on the X axis, in degrees.
Relative Yaw	Template:Type
Pitch	Template:Type	Rotation on the Y axis, in degrees.
Relative Pitch	Template:Type

Recipe Book Add

Template:Packet header
Field Name		Field Type		Notes
Recipes	Recipe ID	Template:Type	Template:Type	ID to assign to the recipe.
	Display		Template:Type
	Group ID		Template:Type
	Category ID		Template:Type	ID in the minecraft:recipe_book_category registry.
	Ingredients		Template:Type Template:Type of Template:Type	IDs in the minecraft:item registry, or an inline definition.
	Flags		Template:Type	0x01: show notification; 0x02: highlight as new
Replace		Template:Type		Replace or Add to known recipes

Recipe Book Remove

Template:Packet header
Field Name	Field Type	Notes
Recipes	Template:Type of Template:Type	IDs of recipes to remove.

Recipe Book Settings

Template:Packet header
Field Name	Field Type	Notes
Crafting Recipe Book Open	Template:Type	If true, then the crafting recipe book will be open when the player opens its inventory.
Crafting Recipe Book Filter Active	Template:Type	If true, then the filtering option is active when the player opens its inventory.
Smelting Recipe Book Open	Template:Type	If true, then the smelting recipe book will be open when the player opens its inventory.
Smelting Recipe Book Filter Active	Template:Type	If true, then the filtering option is active when the player opens its inventory.
Blast Furnace Recipe Book Open	Template:Type	If true, then the blast furnace recipe book will be open when the player opens its inventory.
Blast Furnace Recipe Book Filter Active	Template:Type	If true, then the filtering option is active when the player opens its inventory.
Smoker Recipe Book Open	Template:Type	If true, then the smoker recipe book will be open when the player opens its inventory.
Smoker Recipe Book Filter Active	Template:Type	If true, then the filtering option is active when the player opens its inventory.

Remove Entities

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

Template:Packet header
Field Name	Field Type	Notes
Entity IDs	Template:Type of Template:Type	The list of entities to destroy.

Remove Entity Effect

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type
Effect ID	Template:Type	See this table.

Reset Score

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

Template:Packet header
Field Name	Field Type	Notes
Entity Name	Template:Type (32767)	The entity whose score this is. For players, this is their username; for other entities, it is their UUID.
Objective Name	Template:Type Template:Type (32767)	The name of the objective the score belongs to.

Respawn

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

The background of the loading screen is determined based on the Dimension Name specified in this packet and the one specified in the previous Login or Respawn packet. If either the current or the previous dimension is minecraft:nether, the Nether portal background is used. Otherwise, if the current or the previous dimension is minecraft:the_end, the End portal background is used. If the player is dead (health is 0), the default background is always used.

Template:Packet header
Field Name	Field Type	Notes
Dimension Type	Template:Type	The ID of type of dimension in the minecraft:dimension_type registry, defined by the Template:Packet packet.
Dimension Name	Template:Type	Name of the dimension being spawned into.
Hashed seed	Template:Type	First 8 bytes of the SHA-256 hash of the world's seed. Used client-side for biome noise
Game mode	Template:Type	0: Survival, 1: Creative, 2: Adventure, 3: Spectator.
Previous Game mode	Template:Type	-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	Template:Type	True if the world is a Minecraft:debug mode world; debug mode worlds cannot be modified and have predefined blocks.
Is Flat	Template:Type	True if the world is a Minecraft:superflat world; flat worlds have different void fog and a horizon at y=0 instead of y=63.
Has death location	Template:Type	If true, then the next two fields are present.
Death dimension Name	Template:Type Template:Type	Name of the dimension the player died in.
Death location	Template:Type Template:Type	The location that the player died at.
Portal cooldown	Template:Type	The number of ticks until the player can use the portal again.
Sea level	Template:Type
Data kept	Template:Type	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 vanilla 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.

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.

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type
Head Yaw	Template:Type	New angle, not a delta.

Update Section Blocks

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

Template:Packet header
Field Name	Field Type	Notes
Chunk section position	Template:Type	Chunk section coordinate (encoded chunk x and z with each 22 bits, and section y with 20 bits, from left to right).
Blocks	Template:Type of Template:Type	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 is made in another tab.

Template:Packet header
Field Name	Field Type	Notes
Identifier	Template:Type Template:Type	See below.

The Template:Type must be one of the following if no custom data pack is loaded:

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

Template:Packet header
Field Name	Field Type	Notes
MOTD	Template:Type
Icon	Template:Type Template:Type of Template:Type	Icon bytes in the PNG format.

Set Action Bar Text

Displays a message above the hotbar. Equivalent to Template:Packet with Overlay set to true, except that chat message blocking isn't performed. Used by the vanilla server only to implement the /title command.

Template:Packet header
Field Name	Field Type	Notes
Action bar text	Template:Type

Set Border Center

Template:Packet header
Field Name	Field Type	Notes
X	Template:Type
Z	Template:Type

Set Border Lerp Size

Template:Packet header
Field Name	Field Type	Notes
Old Diameter	Template:Type	Current length of a single side of the world border, in meters.
New Diameter	Template:Type	Target length of a single side of the world border, in meters.
Speed	Template:Type	Number of real-time milliseconds until New Diameter is reached. It appears that vanilla 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

Template:Packet header
Field Name	Field Type	Notes
Diameter	Template:Type	Length of a single side of the world border, in meters.

Set Border Warning Delay

Template:Packet header
Field Name	Field Type	Notes
Warning Time	Template:Type	In seconds as set by /worldborder warning time.

Set Border Warning Distance

Template:Packet header
Field Name	Field Type	Notes
Warning Blocks	Template:Type	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 vanilla 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).

Template:Packet header
Field Name	Field Type	Notes
Camera ID	Template:Type	ID of the entity to set the client's camera to.

The vanilla 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 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 vanilla client never renders or simulates chunks located outside the loading area, but keeps them in memory (unless explicitly unloaded by the server while still in range), and only automatically unloads a chunk when another chunk is loaded at coordinates congruent to the old chunk's coordinates modulo (2 × server view distance + 7). This means that a chunk may reappear after leaving and later re-entering the loading area through successive uses of this packet, unless it is replaced in the meantime by a different chunk in the same "slot".

The vanilla client ignores attempts to load or unload chunks located outside the loading area. This applies even to unloads targeting chunks that are still loaded, but currently located outside the loading area (per the previous paragraph).

The vanilla server does not rely on any specific behavior for chunks leaving the loading area, and custom clients need not replicate the above exactly. A client may instead choose to immediately unload any chunks outside the loading area, to use a different modulus, or to ignore the loading area completely and keep chunks loaded regardless of their location until the server requests to unload them. Servers aiming for maximal interoperability should always explicitly unload any loaded chunks before they go outside the loading area.

The center chunk is normally the chunk the player is in, but apart from the implications on chunk loading, the (vanilla) 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 vanilla 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.

Template:Packet header
Field Name	Field Type	Notes
Chunk X	Template:Type	Chunk X coordinate of the loading area center.
Chunk Z	Template:Type	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.

Template:Packet header
Field Name	Field Type	Notes
View Distance	Template:Type	Render distance (2-32).

Set Cursor Item

Replaces or sets the inventory item that's being dragged with the mouse.

Template:Packet header
Field Name	Field Type	Notes
Carried item	Template:Type

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.

Before receiving this packet, the client uses the default position 8, 64, 8, and angle 0.0.

Template:Packet header
Field Name	Field Type	Notes
Dimension Name	Template:Type	Name of spawn dimension.
Location	Template:Type	Spawn location.
Yaw	Template:Type	Yaw after respawning.
Pitch	Template:Type	Pitch after respawning.

Display Objective

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

Template:Packet header
Field Name	Field Type	Notes
Position	Template:Type	The position of the scoreboard. 0: list, 1: sidebar, 2: below name, 3 - 18: team-specific sidebar, indexed as 3 + team color.
Score Name	Template:Type (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.

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type
Metadata	Entity Metadata

Link Entities

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

Template:Packet header
Field Name	Field Type	Notes
Attached Entity ID	Template:Type	Attached entity's EID.
Holding Entity ID	Template:Type	ID of the entity holding the lead. Set to -1 to detach.

Set Entity Velocity

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type
Velocity	Template:Type

Set Equipment

Template:Packet header
Field Name		Field Type		Notes
Entity ID		Template:Type		Entity's ID.
Equipment	Slot	Template:Type	Template:Type Template:Type	The length of the array is not known beforehand and has to be determined by reading all entries, as the most significant bit of the slot indicates if there is a next entry.	Equipment slot (see below). Also has the top bit set if another entry follows, and otherwise unset if this is the last item in the array.
	Item		Template:Type

Equipment slot can be one of the following:

ID	Equipment slot
0	Main hand
1	Off hand
2	Boots
3	Leggings
4	Chestplate
5	Helmet
6	Body
7	Saddle

Set Experience

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

Template:Packet header
Field Name	Field Type	Notes
Experience bar	Template:Type	Between 0 and 1.
Level	Template:Type
Total Experience	Template:Type	See Minecraft: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.

Template:Packet header
Field Name	Field Type	Notes
Health	Template:Type	0 or less = dead, 20 = full HP.
Food	Template:Type	0–20.
Food Saturation	Template:Type	Seems to vary from 0.0 to 5.0 in integer increments.

Set Held Item (clientbound)

Sent to change the player's slot selection.

Template:Packet header
Field Name	Field Type	Notes
Slot	Template:Type	The slot which the player has selected (0–8).

Update Objectives

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

Template:Packet header
Field Name		Field Type	Notes
Objective Name		Template:Type (32767)	A unique name for the objective.
Mode		Template:Type	0 to create the scoreboard. 1 to remove the scoreboard. 2 to update the display text.
Objective Value		Template:Type Template:Type	Only if mode is 0 or 2.The text to be displayed for the score.
Type		Template:Type Template:Type Template:Type	Only if mode is 0 or 2. 0 = "integer", 1 = "hearts".
Has Number Format		Template:Type Template:Type	Only if mode is 0 or 2. Whether this objective has a set number format for the scores.
Number Format		Template:Type Template:Type Template:Type	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 formatting fields ("color", "bold", etc., but not "text", "extra", etc.).
2: fixed	Content	Template:Type	The text to be used as placeholder.

Set Passengers

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type	Vehicle's EID.
Passengers	Template:Type of Template:Type	EIDs of entity's passengers.

Set Player Inventory Slot

Sets the contents of a player inventory slot directly, bypassing the usual container window mechanism. This packet is used by the vanilla server only when placing items in temporary slots back into the inventory upon closing a container window, and likely exists to work around implementation issues specific to vanilla. It is prone to race conditions because it doesn't include a State ID, and there is generally no reason not to use Template:Packet or Template:Packet instead.

Template:Packet header
Field Name	Field Type	Notes
Slot	Template:Type	Index of the slot to be modified in the player inventory. Not a container window slot index, to the survival inventory or any other window—there is no crafting grid, and the slot order is different.
Slot Data	Template:Type

Update Teams

Creates and updates teams.

Template:Packet header
Field Name		Field Type	Notes
Team Name		Template:Type (32767)	A unique name for the team. (Shared with scoreboard).
Method		Template:Type	Determines the layout of the remaining packet.
0: create team	Team Display Name	Template:Type
	Team Prefix	Template:Type	Displayed before the names of players that are part of this team.
	Team Suffix	Template:Type	Displayed after the names of players that are part of this team.
	Name Tag Visibility	Template:Type Template:Type	0 = ALWAYS, 1 = NEVER, 2 = HIDE_FOR_OTHER_TEAMS, 3 = HIDE_FOR_OWN_TEAMS
	Collision Rule	Template:Type Template:Type	0 = ALWAYS, 1 = NEVER, 2 = PUSH_OTHER_TEAMS, 3 = PUSH_OWN_TEAM
	Team Color	Template:Type Template:Type	Used to color the names of players on the team; see below.
	Friendly Flags	Template:Type	Bit mask. 0x01: Allow friendly fire, 0x02: can see invisible players on the same team.
	Entities	Template:Type of Template:Type (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	Template:Type
	Team Prefix	Template:Type	Displayed before the names of players that are part of this team.
	Team Suffix	Template:Type	Displayed after the names of players that are part of this team.
	Name Tag Visibility	Template:Type Template:Type	0 = ALWAYS, 1 = NEVER, 2 = HIDE_FOR_OTHER_TEAMS, 3 = HIDE_FOR_OWN_TEAMS
	Collision Rule	Template:Type Template:Type	0 = ALWAYS, 1 = NEVER, 2 = PUSH_OTHER_TEAMS, 3 = PUSH_OWN_TEAM
	Team Color	Template:Type Template:Type	Used to color the names of players on the team; see below.
	Friendly Flags	Template:Type	Bit mask. 0x01: Allow friendly fire, 0x02: can see invisible players on the same team.
3: add entities to team	Entities	Template:Type of Template:Type (32767)	Identifiers for the added entities. For players, this is their username; for other entities, it is their UUID.
4: remove entities from team	Entities	Template:Type of Template:Type (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 Minecraft:Formatting codes#Color codes.
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.

Template:Packet header
Field Name		Field Type	Notes
Entity Name		Template:Type (32767)	The entity whose score this is. For players, this is their username; for other entities, it is their UUID.
Objective Name		Template:Type (32767)	The name of the objective the score belongs to.
Value		Template:Type	The score to be displayed next to the entry.
Display Name		Template:Type Template:Type	The custom display name.
Number Format		Template:Type Template:Type Template:Type	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 formatting fields ("color", "bold", etc., but not "text", "extra", etc.).
2: fixed	Content	Template:Type	The text to be used as placeholder.

Set Simulation Distance

Template:Packet header
Field Name	Field Type	Notes
Simulation Distance	Template:Type	Server simulation distance.

The server simulation distance is used by the vanilla client only to determine whether the death animation of an entity should progress. If the integer chessboard distance between the chunk the local player is in (not the chunk cache center) and the chunk the entity is in is greater than the simulation distance, the animation will be paused.

Set Subtitle Text

Template:Packet header
Field Name	Field Type	Notes
Subtitle Text	Template:Type

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.

Template:Packet header
Field Name		Field Type		Notes
World Age		Template:Type		In ticks; not changed by server commands.
Clocks	Clock ID	Template:Type	Template:Type	ID in the minecraft:world_clock registry.
	Time		Template:Type	Current time of the clock, in ticks.
	Fractional time		Template:Type	Fractional part of the time in ticks, normally a nonnegative number less than 1.
	Rate		Template:Type	Rate at which the client should automatically advance the time of the clock, in clock ticks per client tick.

Set Title Text

Template:Packet header
Field Name	Field Type	Notes
Title Text	Template:Type

Set Title Animation Times

Template:Packet header
Field Name	Field Type	Notes
Fade In	Template:Type	Ticks to spend fading in.
Stay	Template:Type	Ticks to keep the title displayed.
Fade Out	Template:Type	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.

Template:Packet header
Field Name	Field Type	Notes
Sound Event	Template:Type Template:Type	ID in the minecraft:sound_event registry, or an inline definition.
Sound Category	Template:Type Template:Type	The category that this sound will be played from (current categories).
Entity ID	Template:Type
Volume	Template:Type	1.0 is 100%, capped between 0.0 and 1.0 by vanilla clients.
Pitch	Template:Type	Float between 0.5 and 2.0 by vanilla clients.
Seed	Template:Type	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.

Template:Packet header
Field Name	Field Type	Notes
Sound Event	Template:Type Template:Type	ID in the minecraft:sound_event registry, or an inline definition.
Sound Category	Template:Type Template:Type	The category that this sound will be played from (current categories).
Effect Position X	Template:Type	Effect X multiplied by 8 (fixed-point number with only 3 bits dedicated to the fractional part).
Effect Position Y	Template:Type	Effect Y multiplied by 8 (fixed-point number with only 3 bits dedicated to the fractional part).
Effect Position Z	Template:Type	Effect Z multiplied by 8 (fixed-point number with only 3 bits dedicated to the fractional part).
Volume	Template:Type	1.0 is 100%, capped between 0.0 and 1.0 by vanilla clients.
Pitch	Template:Type	Float between 0.5 and 2.0 by vanilla clients.
Seed	Template:Type	Seed used to pick sound variant.

Start Configuration

Sent during gameplay in order to redo the configuration process. The client must respond with Template:Packet for the process to start.

Template:Packet header
Field Name	Field Type	Notes
no fields

This packet switches the connection state to configuration.

Stop Sound

Template:Packet header
Field Name	Field Type	Notes
Flags	Template:Type	Controls which fields are present.
Source	Template:Type Template:Type Template:Type	Only if flags is 3 or 1 (bit mask 0x1). See below. If not present, then sounds from all sources are cleared.
Sound	Template:Type Template:Type	Only if flags is 2 or 3 (bit mask 0x2). A sound effect name, see Template:Packet. 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.

Template:Packet header
Field Name	Field Type	Notes
Content	Template:Type	Limited to 262144 bytes.
Overlay	Template:Type	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 tab list. It is never sent by the vanilla server.

Template:Packet header
Field Name	Field Type	Notes
Header	Template:Type	To remove the header, send an empty text component: {"text":""}.
Footer	Template:Type	To remove the footer, send an empty text component: {"text":""}.

Tag Query Response

Sent in response to Template:Packet or Template:Packet.

Template:Packet header
Field Name	Field Type	Notes
Transaction ID	Template:Type	Can be compared to the one sent in the original query packet.
NBT	Template:Type	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 Template:Packet (and Template:Packet) packet sent by the client. The collector entity can be any entity; it does not have to be a player. The collected entity can also be any entity, but the vanilla server only uses this for items, experience orbs, the different varieties of arrows and tridents.

Template:Packet header
Field Name	Field Type	Notes
Collected Entity ID	Template:Type
Collector Entity ID	Template:Type
Pickup Item Count	Template:Type	Seems to be 1 for XP orbs, otherwise the number of items in the stack.

Synchronize Vehicle Position

Teleports the entity on the client without changing the reference point of movement deltas in future Template:Packet packets. Seems to be used to make relative adjustments to vehicle positions; more information needed.

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type
X	Template:Type
Y	Template:Type
Z	Template:Type
Velocity X	Template:Type
Velocity Y	Template:Type
Velocity Z	Template:Type
Yaw	Template:Type	Rotation on the Y axis, in degrees.
Pitch	Template:Type	Rotation on the Y axis, in degrees.
Flags	Template:Type
On Ground	Template:Type

Test Instance Block Status

Updates the status of the currently open Minecraft:Test Instance Block screen, if any.

Template:Packet header
Field Name	Field Type	Notes
Status	Template:Type
Has Size	Template:Type
Size X	Template:Type Template:Type	Only present if Has Size is true.
Size Y	Template:Type Template:Type	Only present if Has Size is true.
Size Z	Template:Type Template:Type	Only present if Has Size is true.

Set Ticking State

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

Template:Packet header
Field Name	Field Type	Notes
Tick rate	Template:Type
Is frozen	Template:Type

Step Tick

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

Template:Packet header
Field Name	Field Type	Notes
Tick steps	Template:Type

Update Advancements

Template:Packet header
Field Name		Field Type		Notes
Reset/Clear		Template:Type		Whether to reset/clear the current advancements.
Advancement mapping	Key	Template:Type	Template:Type	The identifier of the advancement.
	Value		Advancement	See below
Identifiers		Template:Type of Template:Type		The identifiers of the advancements that should be removed.
Progress mapping	Key	Template:Type	Template:Type	The identifier of the advancement.
	Value		Advancement progress	See below.
Show advancements		Template:Type

Advancement structure:

Field Name		Field Type		Notes
Parent id		Template:Type Template:Type		The identifier of the parent advancement.
Display data		Template:Type Advancement display		See below.
Nested requirements		Template:Type	Template:Type of Template:Type (32767)	Array with a sub-array of criteria. To check if the requirements are met, each sub-array must be tested and mapped with the OR operator, resulting in a boolean array. These booleans must be mapped with the AND operator to get the result.
Sends telemetry data		Template:Type		Whether the client should include this achievement in the telemetry data when it's completed. The vanilla client only sends data for advancements on the minecraft namespace.

Advancement display:

Field Name	Field Type	Notes
Title	Template:Type
Description	Template:Type
Icon	Template:Type
Frame type	Template:Type Template:Type	0 = task, 1 = challenge, 2 = goal.
Flags	Template:Type	0x01: has background texture; 0x02: show_toast; 0x04: hidden.
Background texture	Template:Type Template:Type	Background texture location. Only if flags indicates it.
X coord	Template:Type
Y coord	Template:Type

Advancement progress:

Field Name		Field Type		Notes
Criteria	Criterion identifier	Template:Type	Template:Type	The identifier of the criterion.
	Date of achieving		Template:Type Template:Type	Present if achieved. As returned by Date.getTime.

Update Attributes

Sets attributes on the given entity.

Template:Packet header
Field Name		Field Type		Notes
Entity ID		Template:Type
Property	Id	Template:Type	Template:Type	ID in the minecraft:attribute registry. See also Minecraft:Attribute#Attributes.
	Value		Template:Type	See below.
	Modifiers		Template:Type of Modifier Data	See Minecraft:Attribute#Modifiers. Modifier Data defined below.

Modifier Data structure:

Field Name	Field Type	Notes
Id	Template:Type
Amount	Template:Type	May be positive or negative.
Operation	Template:Type	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

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type
Effect ID	Template:Type	See this table.
Amplifier	Template:Type	Vanilla client displays effect level as Amplifier + 1.
Duration	Template:Type	Duration in ticks. (-1 for infinite)
Flags	Template:Type	Bit field, see below.

Within flags:

• 0x01: Is ambient - was the effect spawned from a beacon? All beacon-generated effects are ambient. Ambient effects use a different icon in the HUD (blue border rather than gray). If all effects on an entity are ambient, the "Is potion effect ambient" living metadata field should be set to true. Usually should not be enabled.
• 0x02: Show particles - should all particles from this effect be hidden? Effects with particles hidden are not included in the calculation of the effect color, and are not rendered on the HUD (but are still rendered within the inventory). Usually should be enabled.
• 0x04: Show icon - should the icon be displayed on the client? Usually should be enabled.
• 0x08: Blend - should the effect's hard-coded blending be applied? Currently only used in the DARKNESS effect to apply extra void fog and adjust the gamma value for lighting.

Update Recipes

Template:Packet header
Field Name		Field Type		Notes
Property Sets	Property Set ID	Template:Type	Template:Type
	Items		Template:Type of Template:Type	IDs in the minecraft:item registry.
Stonecutter Recipes	Ingredients	Template:Type	Template:Type
	Slot Display		Template:Type

Projectile Power

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type
Power	Template:Type

Waypoint

Adds, removes, or updates an entry that will be tracked on the player locator bar.

Template:Packet header
Field Name		Field Type		Notes
Operation		Template:Type Template:Type		0: track, 1: untrack, 2: update.
Identifier		Template:Type Template:Type or Template:Type		Something that uniquely identifies this specific waypoint.
Icon style		Template:Type		Path to the waypoint style JSON: assets/<namespace>/waypoint_style/<value>.json.
Color
	Red	Template:Type	Template:Type	The color of the waypoint icon.
	Green		Template:Type
	Blue		Template:Type
Waypoint type		Template:Type Template:Type		Defines how the following field is read.
Waypoint data		Varies		Type Field Name Field Data Notes 0: Empty no fields 1: Vec3i X Template:Type The position that the waypoint will point to. Y Template:Type Z Template:Type 2: Chunk X Template:Type The chunk coordinates that the waypoint will point to. Z Template:Type 3: Azimuth Angle Template:Type The angle that will be pointed to, in radians.

Show Dialog (play)

Show a custom dialog screen to the client.

Template:Packet header
Field Name	Field Type	Notes
Dialog	Template:Type Template:Type	Inline definition as described at Minecraft:Dialog#Dialog format.

Serverbound

Confirm Teleportation

Sent by client as confirmation of Template:Packet.

Template:Packet header
Field Name	Field Type	Notes
Teleport ID	Template:Type	The ID given by the Template:Packet packet.

Attack

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

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

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type	The ID of the attacked entity. Note the special case of the ender dragon described on the Template:Packet packet.

Query Block Entity Tag

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

Template:Packet header
Field Name	Field Type	Notes
Transaction ID	Template:Type	An incremental ID so that the client can verify that the response matches.
Location	Template:Type	The location of the block to check.

Bundle Item Selected

Template:Packet header
Field Name	Field Type	Notes
Slot of Bundle	Template:Type
Slot in Bundle	Template:Type

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.

Template:Packet header
Field Name	Field Type	Notes
New difficulty	Template:Type Template:Type	0: peaceful, 1: easy, 2: normal, 3: hard.

Change Game Mode

Requests for the server to update our game mode. Has no effect on vanilla servers if the client doesn't have the required permissions.

Template:Packet header
Field Name	Field Type	Notes
Game mode	Template:Type Template:Type	0: survival, 1: creative, 2: adventure, 3: spectator.

Acknowledge Message

Template:Packet header
Field Name	Field Type	Notes
Message Count	Template:Type

Chat Command

Template:Packet header
Field Name		Field Type		Notes
Command		Template:Type (32767)		The command typed by the client excluding the /.

Signed Chat Command

Template:Packet header
Field Name		Field Type		Notes
Command		Template:Type (32767)		The command typed by the client excluding the /.
Timestamp		Template:Type		The timestamp that the command was executed.
Salt		Template:Type		The salt for the following argument signatures.
Array of argument signatures	Argument name	Template:Type (8)	Template:Type (16)	The name of the argument that is signed by the following signature.
	Signature		Template:Type (256)	The signature that verifies the argument. Always 256 bytes and is not length-prefixed.
Message Count		Template:Type
Acknowledged		Template:Type (20)
Checksum		Template:Type

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 Template:Packet packet with Chat Type minecraft:chat to all players that haven't disabled chat (including the player that sent the message). See Minecraft:Java Edition protocol/Chat#Processing chat for more information.

Template:Packet header
Field Name	Field Type	Notes
Message	Template:Type (256)	Content of the message
Timestamp	Template:Type	Number of milliseconds since the epoch (1 Jan 1970, midnight, UTC)
Salt	Template:Type	The salt used to verify the signature hash. Randomly generated by the client
Signature	Template:Type Template:Type (256)	The signature used to verify the chat message's authentication. When present, always 256 bytes and not length-prefixed. This is a SHA256 with RSA digital signature computed over the following: The number 1 as a 4-byte int. Always 00 00 00 01. The player's 16-byte UUID. The chat session (a 16-byte UUID randomly generated by the client). The index of the message within this chat session as a 4-byte int. First message is 0, next message is 1, etc. Incremented each time the client sends a chat message. The salt (from above) as an 8-byte long. The timestamp (from above) converted from milliseconds to seconds, so divide by 1000, as an 8-byte long. The length of the message in bytes (from above) as a 4-byte int. The message bytes. The number of messages in the last seen set, as a 4-byte int. Always in the range [0,20]. For each message in the last seen set, from oldest to newest, the 256-byte signature of that message. The client's chat private key is used for the message signature.
Message Count	Template:Type	Number of signed clientbound chat messages the client has seen from the server since the last serverbound chat message from this client. The server will use this to update its last seen list for the client.
Acknowledged	Template:Type (20)	Bitmask of which message signatures from the last seen set were used to sign this message. The most recent is the highest bit. If there are fewer than 20 messages in the last seen set, the lower bits will be zeros.
Checksum	Template:Type	Checksum is computed over all the message signature checksums in the last seen set, from oldest to newest. Both the packet checksum and signature checksums use the same logic as Java's Arrays.hashCode(byte[]) implementation. The packet checksum additionally casts the resulting int to a byte, and if that byte is 0 returns 1, otherwise returns said byte

Player Session

Template:Packet header
Field Name		Field Type	Notes
Session Id		Template:Type
Public Key	Expires At	Template:Type	The time the play session key expires in Template:Wikipedia milliseconds.
	Public Key	Template:Type (512) of Template:Type	A byte array of an X.509-encoded public key.
	Key Signature	Template:Type (4096) of Template:Type	The signature consists of the player UUID, the key expiration timestamp, and the public key data. These values are hashed using Template:Wikipedia and signed using Mojang's private Template:Wikipedia 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 vanilla 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.

Template:Packet header
Field Name	Field Type	Notes
Chunks per tick	Template:Type	Desired chunks per tick.

Client Status

Template:Packet header
Field Name	Field Type	Notes
Action ID	Template:Type Template:Type	See below

Action ID values:

Action ID	Action	Notes
0	Perform respawn	Sent when the client is ready to respawn after death.
1	Request stats	Sent when the client opens the Statistics menu.
2	Request game rule values	Sent when the client opens the Edit Game Rules menu.

Client Tick End

Template:Packet header
Field Name	Field Type	Notes
no fields

Command Suggestions Request

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

Template:Packet header
Field Name	Field Type	Notes
Transaction Id	Template:Type	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	Template:Type (32500)	All the text behind the cursor including 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 Template:Packet packet from the server.

Template:Packet header
Field Name	Field Type	Notes
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.

Template:Packet header
Field Name	Field Type	Notes
Window ID	Template:Type	The ID of the window sent by Template:Packet.
Button ID	Template:Type	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.

Template:Packet header
Field Name		Field Type		Notes
Window ID		Template:Type		The ID of the window that 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		Template:Type		The last received State ID from either a Template:Packet or a Template:Packet packet.
Slot		Template:Type		The clicked slot number, see below.
Button		Template:Type		The button used in the click, see below.
Mode		Template:Type Template:Type		Inventory operation mode, see below.
Array of changed slots	Slot number	Template:Type (128)	Template:Type
	Slot data		Template:Type	New data for this slot, in the client's opinion; see below.
Carried item		Template:Type		Item carried by the cursor.

See Minecraft:Java Edition protocol/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 Template:Packet packets containing the correct results. If State ID does not match the last ID sent by the server, it will instead send a full Template:Packet 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 the 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
	⋮	⋮	Used to allow swapping with arbitrary inventory slots. Ignored since 1.20.3.
	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)
	1	Normal	Control + Drop key (Q)
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 a stack of something (more than 1 item), then holding the mouse button (left, right, or middle) and dragging the held stack over empty (or same type in case of right button) slots. In that case client sends the following to the server after the mouse button release (omitting the 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.

vanilla clients send a Close Window packet with Window ID 0 to close their inventory, even though there is never an Template:Packet packet for the inventory.

Template:Packet header
Field Name	Field Type	Notes
Window ID	Template:Type	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.

Template:Packet header
Field Name	Field Type	Notes
Slot ID	Template:Type	This is the ID of the slot that was changed.
Window ID	Template:Type	This is the ID of the window that was changed.
State	Template:Type	The new state of the slot. True for enabled, false for disabled.

Debug Subscription Request

Sent by the client whenever debug subscriptions, used by Minecraft:debug graphs and renderers, are activated or deactivated. The list in the packet replaces the previous set of active subscriptions. Subscriptions not in the list are deactivated.

If the client does not have permission to receive the requested debug information, the subscriptions are nonetheless retained by the server, and it is not necessary to send this packet again if the permissions change.

Template:Packet header
Field Name	Field Type	Notes
Subscriptions	Template:Type of Template:Type	List of active debug subscriptions. IDs in the minecraft:debug_subscription registry.

Edit Book

Template:Packet header
Field Name	Field Type	Notes
Slot	Template:Type	The hotbar slot where the written book is located
Entries	Template:Type (100) of Template:Type (1024)	Text from each page. Maximum string length is 1024 chars.
Title	Template:Type Template:Type (32)	Title of book. Present if book is being signed, not present if book is being edited.

Query Entity Tag

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

Template:Packet header
Field Name	Field Type	Notes
Transaction ID	Template:Type	An incremental ID so that the client can verify that the response matches.
Entity ID	Template:Type	The ID of the entity to query.

Interact

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

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

The target offset field represents 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 Template:Packet packet instead.

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type	The ID of the entity to interact. Note the special case described below.
Hand	Template:Type Template:Type	Only if Type is interact or interact at; 0: main hand, 1: off hand.
Target offset	Template:Type
Sneak Key Pressed	Template:Type	If the client is pressing the sneak key. Has the same effect as a Player Command Press/Release sneak key preceding the interaction, and the state is permanently changed.

Interaction with the ender dragon is an odd special case characteristic of release deadline–driven design. 8 consecutive entity IDs following the dragon's ID (id + 1, id + 2, ..., id + 8) are reserved for the 8 hitboxes that make up the dragon:

ID offset	Description
0	The dragon itself (never used in this packet)
1	Head
2	Neck
3	Body
4	Tail 1
5	Tail 2
6	Tail 3
7	Wing 1
8	Wing 2

Jigsaw Generate

Sent when Generate is pressed on the Minecraft:Jigsaw Block interface.

Template:Packet header
Field Name	Field Type	Notes
Location	Template:Type	Block entity location.
Levels	Template:Type	Value of the levels slider/max depth to generate.
Keep Jigsaws	Template:Type

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.

Template:Packet header
Field Name	Field Type	Notes
Locked	Template:Type

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 Template:Packet, 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 Template:Packet is sent if the received position deviated from the server's view by more than a meter.

The vanilla 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 1.20.6, 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.

Template:Packet header
Field Name	Field Type	Notes
X	Template:Type	Absolute position.
Feet Y	Template:Type	Absolute feet position, normally Head Y - 1.62.
Z	Template:Type	Absolute position.
Flags	Template:Type	Bit field: 0x01: on ground, 0x02: pushing against wall.

Set Player Position and Rotation

A combination of Template:Packet and Template:Packet.

Template:Packet header
Field Name	Field Type	Notes
X	Template:Type	Absolute position.
Feet Y	Template:Type	Absolute feet position, normally Head Y - 1.62.
Z	Template:Type	Absolute position.
Yaw	Template:Type	Absolute rotation on the X Axis, in degrees.
Pitch	Template:Type	Absolute rotation on the Y Axis, in degrees.
Flags	Template:Type	Bit field: 0x01: on ground, 0x02: pushing against wall.

Set Player Rotation

File:Minecraft-trig-yaw.png

The unit circle for yaw

File:Yaw.png

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 the 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)

Template:Packet header
Field Name	Field Type	Notes
Yaw	Template:Type	Absolute rotation on the X Axis, in degrees.
Pitch	Template:Type	Absolute rotation on the Y Axis, in degrees.
Flags	Template:Type	Bit field: 0x01: on ground, 0x02: pushing against wall.

Set Player Movement Flags

This packet, as well as Template:Packet, Template:Packet, and Template:Packet 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 a 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.

Template:Packet header
Field Name	Field Type	Notes
Flags	Template:Type	Bit field: 0x01: on ground, 0x02: pushing against wall.

Move Vehicle (serverbound)

Sent when a player moves in a client-side-controlled vehicle. Fields are the same as in Template:Packet. Note that all fields use absolute positioning and do not allow for relative positioning.

Template:Packet header
Field Name	Field Type	Notes
X	Template:Type	Absolute position (X coordinate).
Y	Template:Type	Absolute position (Y coordinate).
Z	Template:Type	Absolute position (Z coordinate).
Yaw	Template:Type	Absolute rotation on the vertical axis, in degrees.
Pitch	Template:Type	Absolute rotation on the horizontal axis, in degrees.
On Ground	Template:Type	(This value does not seem to exist)

Paddle Boat

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

Template:Packet header
Field Name	Field Type	Notes
Left paddle turning	Template:Type
Right paddle turning	Template:Type

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 From Block

Used for pick block functionality (middle click) on blocks to retrieve items from the inventory in survival or creative mode or create them in creative mode. See Minecraft:Controls#Pick Block for more information.

Template:Packet header
Field Name	Field Type	Notes
Location	Template:Type	The location of the block.
Include Data	Template:Type	Used to tell the server to include block data in the new stack, works only if in creative mode.

Pick Item From Entity

Used for pick block functionality (middle click) on entities to retrieve items from the inventory in survival or creative mode or create them in creative mode. See Minecraft:Controls#Pick Block for more information.

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type	The ID of the entity to pick.
Include Data	Template:Type	Unused by the vanilla server.

Place Recipe

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

Template:Packet header
Field Name	Field Type	Notes
Window ID	Template:Type
Recipe ID	Template:Type	ID of recipe previously defined in Template:Packet.
Make all	Template:Type	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.

Template:Packet header
Field Name	Field Type	Notes
Flags	Template:Type	Bit mask. 0x02: is flying.

Player Action

Sent when the player mines a block. A vanilla server only accepts digging packets with coordinates within a 6-unit radius between the center of the block and the player's eyes.

Template:Packet header
Field Name	Field Type	Notes
Status	Template:Type Template:Type	The action the player is taking against the block (see below).
Location	Template:Type	Block position.
Face	Template:Type Template:Type	The face being hit (see below).
Sequence	Template:Type	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.
7	Stab

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: sprinting, exiting a bed, jumping with a horse, and opening a horse's inventory while riding it.

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type	Player ID (ignored by the vanilla server)
Action ID	Template:Type Template:Type	The ID of the action, see below.
Jump Boost	Template:Type	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	Leave bed
1	Start sprinting
2	Stop sprinting
3	Start jump with horse
4	Stop jump with horse
5	Open vehicle inventory
6	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

Sent whenever the player presses or releases certain keys. The flags correspond directly to the states of their corresponding keys—the Sprint flag does not depend on whether the player is actually able to sprint at the moment, etc.

Used by the vanilla server for minecart controls, player inputs in the entity_properties Minecraft:predicate, and sneaking (sprinting is still controlled by Template:Packet).

Template:Packet header
Field Name	Field Type	Notes
Flags	Template:Type	Bit mask; see below

The flags are as follows:

Hex Mask	Field
0x01	Forward
0x02	Backward
0x04	Left
0x08	Right
0x10	Jump
0x20	Sneak
0x40	Sprint

Player Loaded

Sent by the client to indicate that it is ready to start simulating the player. The vanilla client sends this when the "Loading terrain..." screen is closed. (But see the caveat below.)

The vanilla client skips ticking the player entity until the tick on which this packet is sent (the first tick will happen between this packet and the next Template:Packet). Other entities and objects will still be ticked.

Once 60 ticks have elapsed since the last Login or Respawn packet, the vanilla client will start ticking the player and skip sending this packet completely, even after the usual conditions for it have been met. This can happen even before the "Start waiting for level chunks" Template:Packet is received. The loading screen is not affected in any way by this timer (except indirectly by the player falling into the void after ticking has started). Likewise, the vanilla server will assume that the client has loaded if it takes longer than 60 server ticks to send this packet. A more robust way to detect this condition is to count the number of Template:Packet packets sent by the client. The first player tick will occur after 60 Client Tick End packets have been sent. To determine when this counter should be restarted following a respawn, the Respawn packet can be sent in a bundle together with a Template:Packet packet.

Template:Packet header
Field Name	Field Type	Notes
no fields

Change Recipe Book Settings

Replaces Recipe Book Data, type 1.

Template:Packet header
Field Name	Field Type	Notes
Book ID	Template:Type Template:Type	0: crafting, 1: furnace, 2: blast furnace, 3: smoker.
Book Open	Template:Type
Filter Active	Template:Type

Set Seen Recipe

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

Template:Packet header
Field Name	Field Type	Notes
Recipe ID	Template:Type	ID of recipe previously defined in Recipe Book Add.

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, and if it is longer than that, then the rename is silently ignored.

Template:Packet header
Field Name	Field Type	Notes
Item name	Template:Type (32767)	The new name of the item.

Seen Advancements

Template:Packet header
Field Name	Field Type	Notes
Action	Template:Type Template:Type	0: Opened tab, 1: Closed screen.
Tab ID	Template:Type Template:Type	Only present if action is Opened tab.

Select Trade

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

Template:Packet header
Field Name	Field Type	Notes
Selected slot	Template:Type	The selected slot in the player's current (trading) inventory.

Set Beacon Effect

Changes the effect of the current beacon.

Template:Packet header
Field Name	Field Type	Notes
Primary Effect	Template:Type Template:Type	A Potion ID.
Secondary Effect	Template:Type Template:Type	A Potion ID.

Set Held Item (serverbound)

Sent when the player changes the slot selection.

Template:Packet header
Field Name	Field Type	Notes
Slot	Template:Type	The slot which the player has selected (0–8).

Program Command Block

Template:Packet header
Field Name	Field Type	Notes
Location	Template:Type
Command	Template:Type (32767)
Mode	Template:Type Template:Type	0: chain, 1: repeating, 2: impulse.
Flags	Template:Type	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

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type
Command	Template:Type (32767)
Track Output	Template:Type	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 2×2 crafting menu, even though they aren't visible in the vanilla client).

Template:Packet header
Field Name	Field Type	Notes
Slot	Template:Type	Inventory slot.
Clicked Item	Template:Type

Set Game Rules

Template:Packet header
Field Name		Field Type		Notes
Rules	Name	Template:Type	Template:Type
	Value		Template:Type (32767)

Program Jigsaw Block

Sent when Done is pressed on the Minecraft:Jigsaw Block interface.

Template:Packet header
Field Name	Field Type	Notes
Location	Template:Type	Block entity location
Name	Template:Type
Target	Template:Type
Pool	Template:Type
Final state	Template:Type (32767)	"Turns into" on the GUI, final_state in NBT.
Joint type	Template:Type (32767)	rollable if the attached piece can be rotated, else aligned.
Selection priority	Template:Type
Placement priority	Template:Type

Program Structure Block

Template:Packet header
Field Name	Field Type	Notes
Location	Template:Type	Block entity location.
Action	Template:Type Template:Type	An additional action to perform beyond simply saving the given data; see below.
Mode	Template:Type Template:Type	One of SAVE (0), LOAD (1), CORNER (2), DATA (3).
Name	Template:Type (32767)
Offset X	Template:Type	Between -48 and 48.
Offset Y	Template:Type	Between -48 and 48.
Offset Z	Template:Type	Between -48 and 48.
Size X	Template:Type	Between 0 and 48.
Size Y	Template:Type	Between 0 and 48.
Size Z	Template:Type	Between 0 and 48.
Mirror	Template:Type Template:Type	One of NONE (0), LEFT_RIGHT (1), FRONT_BACK (2).
Rotation	Template:Type Template:Type	One of NONE (0), CLOCKWISE_90 (1), CLOCKWISE_180 (2), COUNTERCLOCKWISE_90 (3).
Metadata	Template:Type (128)
Integrity	Template:Type	Between 0 and 1.
Seed	Template:Type
Flags	Template:Type	0x01: Ignore entities; 0x02: Show air; 0x04: Show bounding box; 0x08: Strict placement.

Possible actions:

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

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

Set Test Block

Updates the value of the Minecraft:Test Block at the given position.

Template:Packet header
Field Name	Field Type	Notes
Position	Template:Type
Mode	Template:Type Template:Type	0: start, 1: log, 2: fail, 3: accept
Message	Template:Type

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 Template:Packet, otherwise this packet is silently ignored.

Template:Packet header
Field Name	Field Type	Notes
Location	Template:Type	Block Coordinates.
Is Front Text	Template:Type	Whether the updated text is in front or on the back of the sign
Line 1	Template:Type (384)	First line of text in the sign.
Line 2	Template:Type (384)	Second line of text in the sign.
Line 3	Template:Type (384)	Third line of text in the sign.
Line 4	Template:Type (384)	Fourth line of text in the sign.

Spectator Action

Sent when the player left-clicks in spectator mode.

Template:Packet header
Field Name	Field Type	Notes
Entity ID	Template:Type	If 0, the player was not targeting an entity. Otherwise the ID of the targeted entity plus 1.

Swing Arm

Sent when the player's arm swings.

Template:Packet header
Field Name	Field Type	Notes
Hand	Template:Type Template:Type	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 vanilla 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.

Template:Packet header
Field Name	Field Type	Notes
Target Player	Template:Type	UUID of the player to teleport to (can also be an entity UUID).

Test Instance Block Action

Tries to perform an action the Minecraft:Test Instance Block at the given position.

Template:Packet header
Field Name	Field Type	Notes
Position	Template:Type
Action	Template:Type Template:Type	0: init, 1: query, 2: set, 3: reset, 4: save, 5: export, 6: run.
Test	Template:Type Template:Type	ID in the minecraft:test_instance registry.
Size X	Template:Type
Size Y	Template:Type
Size Z	Template:Type
Rotation	Template:Type Template:Type	0: none, 1: clockwise 90°, 2: clockwise 180°, 3: counter-clockwise 90°.
Ignore Entities	Template:Type
Status	Template:Type Template:Type	0: cleared, 1: running, 2: finished.
Error Message	Template:Type Template:Type

Use Item On

Template:Packet header
Field Name	Field Type	Notes
Hand	Template:Type Template:Type	The hand from which the block is placed; 0: main hand, 1: off hand.
Location	Template:Type	Block position.
Face	Template:Type Template:Type	The face on which the block is placed (as documented at Template:Packet).
Cursor Position X	Template:Type	The position of the crosshair on the block, from 0 to 1 increasing from west to east.
Cursor Position Y	Template:Type	The position of the crosshair on the block, from 0 to 1 increasing from bottom to top.
Cursor Position Z	Template:Type	The position of the crosshair on the block, from 0 to 1 increasing from north to south.
Inside block	Template:Type	True when the player's head is inside of a block.
World Border Hit	Template:Type	Seems to always be false, even when interacting with blocks around or outside the world border, or while the player is outside the border.
Sequence	Template:Type	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.

Template:Packet header
Field Name	Field Type	Notes
Hand	Template:Type Template:Type	Hand used for the animation. 0: main hand, 1: off hand.
Sequence	Template:Type	Block change sequence number (see #Acknowledge Block Change).
Yaw	Template:Type	Player head rotation around the Y-Axis.
Pitch	Template:Type	Player head rotation around the X-Axis.

The player's rotation is permanently updated according to the Yaw and Pitch fields before performing the action, unless there is no item in the specified hand.