Pre-release protocol

This page documents the changes from the last stable Minecraft release (currently 1.19.4, protocol 762) to the current pre-release (currently 23w16a, protocol Snapshot 131). Note that this page contains bleeding-edge information that may not be completely or correctly 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

No changes so far.

Packets

ID	Packet name	Documentation
Play clientbound
0x31	Open Sign Editor	Current	Pre
0x6B	Feature Flags	Current	Pre
0x6D	Update Recipes	Current	Pre
Play serverbound
0x2E	Update Sign	Current	Pre

New/modified data types

No changes so far.

Entity Metadata

No changes so far.

Entity

No changes so far.

Block Actions

No changes so far.

Inventories

Type	Name	Description
0	minecraft:generic_9x1	A 1-row inventory, not used by the notchian server.
1	minecraft:generic_9x2	A 2-row inventory, not used by the notchian server.
2	minecraft:generic_9x3	General-purpose 3-row inventory. Used by Chest, minecart with chest, ender chest, and barrel
3	minecraft:generic_9x4	A 4-row inventory, not used by the notchian server.
4	minecraft:generic_9x5	A 5-row inventory, not used by the notchian server.
5	minecraft:generic_9x6	General-purpose 6-row inventory, used by large chests.
6	minecraft:generic_3x3	General-purpose 3-by-3 square inventory, used by Dispenser and Dropper
7	minecraft:anvil	Anvil
8	minecraft:beacon	Beacon
9	minecraft:blast_furnace	Blast Furnace
10	minecraft:brewing_stand	Brewing stand
11	minecraft:crafting	Crafting table
12	minecraft:enchantment	Enchantment table
13	minecraft:furnace	Furnace
14	minecraft:grindstone	Grindstone
15	minecraft:hopper	Hopper or minecart with hopper
16	minecraft:lectern	Lectern
17	minecraft:loom	Loom
18	minecraft:merchant	Villager, Wandering Trader
19	minecraft:shulker_box	Shulker box
20	minecraft:legacy_smithing	Smithing Table The Notchian server only sends this type if feature flag update_1_20 was not enabled
21 20	minecraft:smithing	Smithing Table The Notchian server only sends this type if feature flag update_1_20 was enabled
22 21	minecraft:smoker	Smoker
23 22	minecraft:cartography	Cartography Table
24 23	minecraft:stonecutter	Stonecutter

Plugin Channels

No changes so far.

Play

Clientbound

Open Sign Editor

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

Packet ID	State	Bound To	Field Name	Field Type	Notes
0x31	Play	Client	Location	Position
			Is Front Text	Boolean	Whether the opened editor is for the front or on the back of the sign

Feature Flags

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

Packet ID	State	Bound To	Field Name	Field Type	Notes
0x6B	Play	Client	Total Features	VarInt	Number of features that appear in the array below.
			Feature Flags	Identifier Array

As of 1.19.4 1.20, the following feature flags are available:

• minecraft:vanilla - enables vanilla features
• minecraft:bundle - enables support for the bundle
• minecraft:update_1_20 - enables all the Minecraft 1.20 features that are available in 1.19.4

Update Recipes

Packet ID	State	Bound To	Field Name		Field Type		Notes
0x6D	Play	Client	Num Recipes		VarInt		Number of elements in the following array.
			Recipe	Type	Array	Identifier	The recipe type, see below.
				Recipe ID		Identifier
				Data		Varies	Additional data for the recipe.

Recipe types:

Type	Description	Data
minecraft:crafting_shapeless	Shapeless crafting recipe. All items in the ingredient list must be present, but in any order/slot.	As follows: Name Type Description Group String Used to group similar recipes together in the recipe book. Tag is present in recipe JSON. Category VarInt Enum Building = 0, Redstone = 1, Equipment = 2, Misc = 3 Ingredient count VarInt Number of elements in the following array. Ingredients Array of Ingredient. Result Slot
minecraft:crafting_shaped	Shaped crafting recipe. All items must be present in the same pattern (which may be flipped horizontally or translated).	As follows: Name Type Description Width VarInt Height VarInt Group String Used to group similar recipes together in the recipe book. Tag is present in recipe JSON. Category VarInt Enum Building = 0, Redstone = 1, Equipment = 2, Misc = 3 Ingredients Array of Ingredient Length is width * height. Indexed by x + (y * width). Result Slot Show notification Boolean Show a toast when the recipe is added.
minecraft:crafting_special_armordye	Recipe for dying leather armor	As follows: Name Type Description Category VarInt Enum Building = 0, Redstone = 1, Equipment = 2, Misc = 3
minecraft:crafting_special_bookcloning	Recipe for copying contents of written books
minecraft:crafting_special_mapcloning	Recipe for copying maps
minecraft:crafting_special_mapextending	Recipe for adding paper to maps
minecraft:crafting_special_firework_rocket	Recipe for making firework rockets
minecraft:crafting_special_firework_star	Recipe for making firework stars
minecraft:crafting_special_firework_star_fade	Recipe for making firework stars fade between multiple colors
minecraft:crafting_special_repairitem	Recipe for repairing items via crafting
minecraft:crafting_special_tippedarrow	Recipe for crafting tipped arrows
minecraft:crafting_special_bannerduplicate	Recipe for copying banner patterns
minecraft:crafting_special_shielddecoration	Recipe for applying a banner's pattern to a shield
minecraft:crafting_special_shulkerboxcoloring	Recipe for recoloring a shulker box
minecraft:crafting_special_suspiciousstew	Recipe for crafting suspicious stews
minecraft:crafting_decorated_pot	Recipe for crafting decorated pots The Notchian server only sends this recipe if feature flag update_1_20 was enabled
minecraft:smelting	Smelting recipe	As follows: Name Type Description Group String Used to group similar recipes together in the recipe book. Category VarInt Enum Food = 0, Blocks = 1, Misc = 2 Ingredient Ingredient Result Slot Experience Float Cooking time VarInt
minecraft:blasting	Blast furnace recipe
minecraft:smoking	Smoker recipe
minecraft:campfire_cooking	Campfire recipe
minecraft:stonecutting	Stonecutter recipe	As follows: Name Type Description Group String Used to group similar recipes together in the recipe book. Tag is present in recipe JSON. Ingredient Ingredient Result Slot
minecraft:smithing	Smithing table recipe The Notchian server only sends this recipe if feature flag update_1_20 was not enabled	As follows: Name Type Description Base Ingredient First item. Addition Ingredient Second item. Result Slot
minecraft:smithing_transform	Recipe for smithing netherite gear The Notchian server only sends this recipe if feature flag update_1_20 was enabled. It supersedes the minecraft:smithing recipe type	As follows: Name Type Description Template Ingredient The smithing template. Base Ingredient The base item. Addition Ingredient The additional ingredient. Result Slot
minecraft:smithing_trim	Recipe for applying armor trims The Notchian server only sends this recipe if feature flag update_1_20 was enabled. It supersedes the minecraft:smithing recipe type	As follows: Name Type Description Template Ingredient The smithing template. Base Ingredient The base item. Addition Ingredient The additional ingredient.

Ingredient is defined as:

Name	Type	Description
Count	VarInt	Number of elements in the following array.
Items	Array of Slot	Any item in this array may be used for the recipe. The count of each item should be 1.

Serverbound

Update Sign

This message is sent from the client to the server when the “Done” button is pushed after placing a sign.

The server only accepts this packet after Open Sign Editor, otherwise this packet is silently ignored.

Packet ID	State	Bound To	Field Name	Field Type	Notes
0x2E	Play	Server	Location	Position	Block Coordinates.
			Is Front Text	Boolean	Whether the updated text is in front or on the back of the sign
			Line 1	String (384)	First line of text in the sign.
			Line 2	String (384)	Second line of text in the sign.
			Line 3	String (384)	Third line of text in the sign.
			Line 4	String (384)	Fourth line of text in the sign.

Status

Clientbound

No changes so far.

Serverbound

No changes so far.

Login

Clientbound

No changes so far.

Serverbound

No changes so far.