Minecraft:Java Edition protocol/Development version

This page documents the changes from release 1.21.10 (protocol 773) to the current release (26.2, protocol 776). The stable protocol documentation is currently lagging behind, and the changes documented here will be merged soon, once they are complete. For previous development version pages, see the Protocol version numbers page.

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

Contents

Data types

No changes so far.

Handshaking

|}

Status

|}

|}

Login

|}

|}

Configuration

|}

|}

Play

|}

|}

Login

Clientbound

Login Success

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

Play

Clientbound

Game Rule Values

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

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

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
	Friendly Flags	Template:Type	Bit mask. 0x01: Allow friendly fire, 0x02: can see invisible players on the same team.
	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.
	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.
	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
	Friendly Flags	Template:Type	Bit mask. 0x01: Allow friendly fire, 0x02: can see invisible entities on the same team.
	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.
	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.
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 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.
Time of day		Template:Type		The world (or region) time, in ticks.
Time of day increasing		Template:Type		If true, the client should automatically advance the time of day according to its ticking rate.
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.

Serverbound

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.

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.

Interact

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

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

The target Template:Change representTemplate:Change 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.
Type	Template:Type Template:Type	0: interact, 1: attack, 2: interact at.
Target X	Template:Type Template:Type	Only if Type is interact at.
Target Y	Template:Type Template:Type	Only if Type is interact at.
Target Z	Template:Type Template:Type	Only if Type is interact at.
Hand	Template:Change 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

Set Game Rules

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

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.