This page documents the changes from release 1.21.1 (protocol 767) to the current release (1.21.3, protocol 768). The stable protocol documentation is currently lagging behind, and the changes documented here will be merged soon, once they are complete. The current pre-release (snapshot 24w44a) is not yet documented.
One who wishes to commandeer the merging of this into Protocol when an update is made must be sure to respect any changes that may have occurred to the respective packets there.
Contents
Data types
| Name
|
Size (bytes)
|
Encodes
|
Notes
|
| ID Set
|
Varies
|
Set of registry IDs specified either inline or as a reference to a tag.
|
See #ID Set
|
ID Set
Represents a set of IDs in a certain registry (implied by context), either directly (enumerated IDs) or indirectly (tag name).
| Name
|
Type
|
Description
|
| Type
|
VarInt
|
Identifier used to determine the data that follows. It can be either:
- 0 - Represents a named set of IDs defined by a tag.
- Anything else - Represents an ad-hoc set of IDs enumerated inline.
|
| Tag Name
|
Optional Identifier
|
The registry tag defining the ID set. Only present if Type is 0.
|
| IDs
|
Optional Array of VarInt
|
An array of registry IDs. Only present if Type is not 0.
The size of the array is equal to Type - 1.
|
Packets
| ID
|
Packet name
|
Documentation
|
| Play clientbound
|
| 0x20 |
Synchronize Entity Position |
|
Pre
|
| 0x31 |
Move Minecart Along Track |
|
Pre
|
| 0x41 |
Update Recipe Book |
Current |
|
| 0x43 |
Player Rotation |
|
Pre
|
| 0x44 |
Recipe Book Add |
|
Pre
|
| 0x45 |
Recipe Book Remove |
|
Pre
|
| 0x46 |
Recipe Book Settings |
|
Pre
|
0x53 0x63 |
Set Held Item |
Current |
(unchanged)
|
| 0x5a |
Set Cursor Item |
|
Pre
|
| 0x66 |
Set Player Inventory Slot |
|
Pre
|
| Play serverbound
|
| 0x02 |
Bundle Item Selected |
|
Pre
|
| 0x0b |
Client Tick End |
|
Pre
|
Handshake
No changes so far.
Status
No changes so far.
Login
No changes so far.
Configuration
No changes so far.
Play
Clientbound
Synchronize Entity Position
Move Minecart Along Track
Player Rotation
| Packet ID
|
State
|
Bound To
|
Field Name
|
Field Type
|
Notes
|
| 0x43
|
Play
|
Client
|
Yaw
|
Float
|
Rotation on the X axis, in degrees.
|
| Pitch
|
Float
|
Rotation on the Y axis, in degrees.
|
Recipe Book Add
| Packet ID
|
State
|
Bound To
|
Field Name
|
Field Type
|
Notes
|
| 0x44
|
Play
|
Client
|
Recipe Count
|
VarInt
|
Number of elements in the following array.
|
| Recipes
|
Recipe ID
|
Array
|
VarInt
|
ID to assign to the recipe.
|
| Display ID
|
VarInt
|
ID in the minecraft:recipe_display registry.
|
| Group ID
|
VarInt
|
|
| Category ID
|
VarInt
|
ID in the minecraft:recipe_book_category registry.
|
| Has Ingredients
|
Boolean
|
|
| Ingredient Count
|
Optional VarInt
|
Number of elements in the following array. Only present if Has Ingredients is true.
|
| Ingredients
|
Optional Array of ID Set
|
Only present if Has Ingredients is true.
|
| Flags
|
Byte
|
0x01: show notification; 0x02: hightlight as new
|
Recipe Book Remove
| Packet ID
|
State
|
Bound To
|
Field Name
|
Field Type
|
Notes
|
| 0x45
|
Play
|
Client
|
Recipe Count
|
VarInt
|
Number of elements in the following array.
|
| Recipes
|
Array of VarInt
|
IDs of recipes to remove.
|
Recipe Book Settings
| Packet ID
|
State
|
Bound To
|
Field Name
|
Field Type
|
Notes
|
| 0x46
|
Play
|
Client
|
Crafting Recipe Book Open
|
Boolean
|
If true, then the crafting recipe book will be open when the player opens its inventory.
|
| Crafting Recipe Book Filter Active
|
Boolean
|
If true, then the filtering option is active when the players opens its inventory.
|
| Smelting Recipe Book Open
|
Boolean
|
If true, then the smelting recipe book will be open when the player opens its inventory.
|
| Smelting Recipe Book Filter Active
|
Boolean
|
If true, then the filtering option is active when the players opens its inventory.
|
| Blast Furnace Recipe Book Open
|
Boolean
|
If true, then the blast furnace recipe book will be open when the player opens its inventory.
|
| Blast Furnace Recipe Book Filter Active
|
Boolean
|
If true, then the filtering option is active when the players opens its inventory.
|
| Smoker Recipe Book Open
|
Boolean
|
If true, then the smoker recipe book will be open when the player opens its inventory.
|
| Smoker Recipe Book Filter Active
|
Boolean
|
If true, then the filtering option is active when the players opens its inventory.
|
Set Cursor Item
| Packet ID
|
State
|
Bound To
|
Field Name
|
Field Type
|
Notes
|
| 0x5A
|
Play
|
Client
|
Slot Data
|
Slot
|
|
Set Player Inventory Slot
| Packet ID
|
State
|
Bound To
|
Field Name
|
Field Type
|
Notes
|
| 0x66
|
Play
|
Client
|
Slot
|
VarInt
|
|
| Slot Data
|
Slot
|
|
Serverbound
Bundle Item Selected
| Packet ID
|
State
|
Bound To
|
Field Name
|
Field Type
|
Notes
|
| 0x02
|
Play
|
Server
|
Slot of Bundle
|
VarInt
|
|
| Slot in Bundle
|
VarInt
|
|
Client Tick End
| Packet ID
|
State
|
Bound To
|
Field Name
|
Field Type
|
Notes
|
| 0x0B
|
Play
|
Server
|
no fields
|
