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

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Status

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Login

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Configuration

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Play

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Play

Clientbound

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

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