2026.01.24 6e2d4fc36 interface_

Interface_ Packets

Version: 2026.01.24-6e2d4fc36

This category contains 32 packet(s).

Packet Index

ID	Name	Package	Compressed	Max Size
-	PortalDef	com.hypixel.hytale.protocol.packets.interface_	No	15.6 MB
-	ServerPlayerListUpdate	com.hypixel.hytale.protocol.packets.interface_	No	32 bytes
-	EditorSelection	com.hypixel.hytale.protocol.packets.interface_	No	24 bytes
-	CustomUIEventBinding	com.hypixel.hytale.protocol.packets.interface_	No	31.3 MB
-	CustomUICommand	com.hypixel.hytale.protocol.packets.interface_	No	46.9 MB
-	BlockChange	com.hypixel.hytale.protocol.packets.interface_	No	17 bytes
-	FluidChange	com.hypixel.hytale.protocol.packets.interface_	No	17 bytes
-	PortalState	com.hypixel.hytale.protocol.packets.interface_	No	5 bytes
-	ServerPlayerListPlayer	com.hypixel.hytale.protocol.packets.interface_	No	15.6 MB
0xD2	ServerMessage	com.hypixel.hytale.protocol.packets.interface_	No	1600 MB
0xD3	ChatMessage	com.hypixel.hytale.protocol.packets.interface_	No	15.6 MB
0xD4	Notification	com.hypixel.hytale.protocol.packets.interface_	No	1600 MB
0xD5	KillFeedMessage	com.hypixel.hytale.protocol.packets.interface_	No	1600 MB
0xD6	ShowEventTitle	com.hypixel.hytale.protocol.packets.interface_	No	1600 MB
0xD7	HideEventTitle	com.hypixel.hytale.protocol.packets.interface_	No	4 bytes
0xD8	SetPage	com.hypixel.hytale.protocol.packets.interface_	No	2 bytes
0xD9	CustomHud	com.hypixel.hytale.protocol.packets.interface_	Yes	1600 MB
0xDA	CustomPage	com.hypixel.hytale.protocol.packets.interface_	Yes	1600 MB
0xDB	CustomPageEvent	com.hypixel.hytale.protocol.packets.interface_	No	15.6 MB
0xDE	EditorBlocksChange	com.hypixel.hytale.protocol.packets.interface_	Yes	132.8 MB
0xDF	ServerInfo	com.hypixel.hytale.protocol.packets.interface_	No	31.3 MB
0xE0	AddToServerPlayerList	com.hypixel.hytale.protocol.packets.interface_	No	1600 MB
0xE1	RemoveFromServerPlayerList	com.hypixel.hytale.protocol.packets.interface_	No	62.5 MB
0xE2	UpdateServerPlayerList	com.hypixel.hytale.protocol.packets.interface_	No	125.0 MB
0xE3	UpdateServerPlayerListPing	com.hypixel.hytale.protocol.packets.interface_	No	78.1 MB
0xE4	UpdateKnownRecipes	com.hypixel.hytale.protocol.packets.interface_	No	1600 MB
0xE5	UpdatePortal	com.hypixel.hytale.protocol.packets.interface_	No	15.6 MB
0xE6	UpdateVisibleHudComponents	com.hypixel.hytale.protocol.packets.interface_	No	3.9 MB
0xE7	ResetUserInterfaceState	com.hypixel.hytale.protocol.packets.interface_	No	-
0xE8	UpdateLanguage	com.hypixel.hytale.protocol.packets.interface_	No	15.6 MB
0xE9	WorldSavingStatus	com.hypixel.hytale.protocol.packets.interface_	No	1 bytes
0xEA	OpenChatWithCommand	com.hypixel.hytale.protocol.packets.interface_	No	15.6 MB

---

PortalDef

Property	Value
Compressed	No
Fixed Block Size	9 bytes
Variable Field Count	1
Max Size	15.6 MB
Nullable Bit Field	1 byte(s)
Variable Block Start	9

Fields

Name	Type	Offset	Size	Encoding	Nullable
nameKey	String	-1	var	var_string:utf8	Yes
explorationSeconds	int	1	4	int32_le	No
breachSeconds	int	5	4	int32_le	No

Layout Notes: Fixed block contains nullBits at offset 0, explorationSeconds at offset 1, breachSeconds at offset 5. Variable data (nameKey) starts at offset 9 if present.

---

ServerPlayerListUpdate

Property	Value
Compressed	No
Fixed Block Size	32 bytes
Variable Field Count	0
Max Size	32 bytes
Variable Block Start	32

Fields

Name	Type	Offset	Size	Encoding	Nullable
uuid	UUID	0	16	uuid	No
worldUuid	UUID	16	16	uuid	No

Layout Notes: Fixed block contains two UUIDs at offsets 0 and 16, total size 32 bytes

---

EditorSelection

Property	Value
Compressed	No
Fixed Block Size	24 bytes
Variable Field Count	0
Max Size	24 bytes
Variable Block Start	24

Fields

Name	Type	Offset	Size	Encoding	Nullable
minX	int	0	4	int32_le	No
minY	int	4	4	int32_le	No
minZ	int	8	4	int32_le	No
maxX	int	12	4	int32_le	No
maxY	int	16	4	int32_le	No
maxZ	int	20	4	int32_le	No

Layout Notes: All fields are fixed-size 4-byte integers at specified offsets within the 24-byte fixed block.

---

CustomUIEventBinding

Property	Value
Compressed	No
Fixed Block Size	3 bytes
Variable Field Count	2
Max Size	31.3 MB
Nullable Bit Field	1 byte(s)
Variable Block Start	11

Fields

Name	Type	Offset	Size	Encoding	Nullable
type	CustomUIEventBindingType	1	1	byte	No
selector	String	-1	var	var_string:utf8	Yes
data	String	-1	var	var_string:utf8	Yes
locksInterface	boolean	2	1	byte	No

Layout Notes: Fixed block contains nullable bits at offset 0, type at offset 1, boolean at offset 2. Variable strings are stored in variable block at offsets specified by int32 pointers at offset + 3 (selector) and offset + 7 (data).

type enum values:

• 0 = Activating
• 1 = RightClicking
• 2 = DoubleClicking
• 3 = MouseEntered
• 4 = MouseExited
• 5 = ValueChanged
• 6 = ElementReordered
• 7 = Validating
• 8 = Dismissing
• 9 = FocusGained
• 10 = FocusLost
• 11 = KeyDown
• 12 = MouseButtonReleased
• 13 = SlotClicking
• 14 = SlotDoubleClicking
• 15 = SlotMouseEntered
• 16 = SlotMouseExited
• 17 = DragCancelled
• 18 = Dropped
• 19 = SlotMouseDragCompleted
• 20 = SlotMouseDragExited
• 21 = SlotClickReleaseWhileDragging
• 22 = SlotClickPressWhileDragging
• 23 = SelectedTabChanged

---

CustomUICommand

Property	Value
Compressed	No
Fixed Block Size	2 bytes
Variable Field Count	3
Max Size	46.9 MB
Nullable Bit Field	1 byte(s)
Variable Block Start	14

Fields

Name	Type	Offset	Size	Encoding	Nullable
type	CustomUICommandType	0	1	byte	No
selector	String	-1	var	var_string:utf8	Yes
data	String	-1	var	var_string:utf8	Yes
text	String	-1	var	var_string:utf8	Yes

Layout Notes: Fixed block contains nullable bits at offset 0, and offset pointers at offsets 2, 6, and 10 respectively. Variable data starts at offset + 14.

type enum values:

• 0 = Append
• 1 = AppendInline
• 2 = InsertBefore
• 3 = InsertBeforeInline
• 4 = Remove
• 5 = Set
• 6 = Clear

---

BlockChange

Property	Value
Compressed	No
Fixed Block Size	17 bytes
Variable Field Count	0
Max Size	17 bytes
Variable Block Start	17

Fields

Name	Type	Offset	Size	Encoding	Nullable
x	int	0	4	int32_le	No
y	int	4	4	int32_le	No
z	int	8	4	int32_le	No
block	int	12	4	int32_le	No
rotation	byte	16	1	byte	No

Layout Notes: All fields are fixed size and located sequentially from the given offset

---

FluidChange

Property	Value
Compressed	No
Fixed Block Size	17 bytes
Variable Field Count	0
Max Size	17 bytes
Variable Block Start	17

Fields

Name	Type	Offset	Size	Encoding	Nullable
x	int	0	4	int32_le	No
y	int	4	4	int32_le	No
z	int	8	4	int32_le	No
fluidId	int	12	4	int32_le	No
fluidLevel	byte	16	1	byte	No

Layout Notes: All fields are fixed size and located sequentially from the given offset

---

PortalState

Property	Value
Compressed	No
Fixed Block Size	5 bytes
Variable Field Count	0
Max Size	5 bytes
Variable Block Start	5

Fields

Name	Type	Offset	Size	Encoding	Nullable
remainingSeconds	int	0	4	int32_le	No
breaching	boolean	4	1	byte	No

Layout Notes: Packet consists of a 4-byte integer 'remainingSeconds' and a 1-byte boolean 'breaching'. No nullable bits or variable-length fields.

---

ServerPlayerListPlayer

Property	Value
Compressed	No
Fixed Block Size	37 bytes
Variable Field Count	1
Max Size	15.6 MB
Nullable Bit Field	1 byte(s)
Variable Block Start	37

Fields

Name	Type	Offset	Size	Encoding	Nullable
uuid	UUID	1	16	uuid	No
username	String	-1	var	var_string:utf8	Yes
worldUuid	UUID	17	16	uuid	Yes
ping	int	33	4	int32_le	No

Layout Notes: Fixed block contains nullable bits at offset 0, UUIDs at offsets 1 and 17, ping at offset 33. Variable data (username) is at offset 37, with offset pointer read from variable block if present.

---

ServerMessage

Property	Value
Packet ID	0xD2 (210)
Compressed	No
Fixed Block Size	2 bytes
Variable Field Count	1
Max Size	1600 MB
Nullable Bit Field	1 byte(s)
Variable Block Start	2

Fields

Name	Type	Offset	Size	Encoding	Nullable
type	ChatType	1	1	byte	No
message	FormattedMessage	-1	var	nested:FormattedMessage	Yes

Layout Notes: Fixed block contains nullable bits at offset 0, type byte at offset 1, message at variable position if present

type enum values:

• 0 = Chat

---

ChatMessage

Property	Value
Packet ID	0xD3 (211)
Compressed	No
Fixed Block Size	1 bytes
Variable Field Count	1
Max Size	15.6 MB
Nullable Bit Field	1 byte(s)
Variable Block Start	1

Fields

Name	Type	Offset	Size	Encoding	Nullable
message	String	-1	var	var_string:utf8	Yes

Layout Notes: Fixed block contains nullable bits at offset 0; variable block starts at offset 1 and contains the message string if present

---

Notification

Property	Value
Packet ID	0xD4 (212)
Compressed	No
Fixed Block Size	2 bytes
Variable Field Count	4
Max Size	1600 MB
Nullable Bit Field	1 byte(s)
Variable Block Start	18

Fields

Name	Type	Offset	Size	Encoding	Nullable
message	FormattedMessage	-1	var	nested:FormattedMessage	Yes
secondaryMessage	FormattedMessage	-1	var	nested:FormattedMessage	Yes
icon	String	-1	var	var_string:utf8	Yes
item	ItemWithAllMetadata	-1	var	nested:ItemWithAllMetadata	Yes
style	NotificationStyle	1	1	byte	No

Layout Notes: Fixed block contains nullable bits at offset 0 and style byte at offset 1. Variable data offsets stored at fixed block offsets 2, 6, 10, 14 respectively.

style enum values:

• 0 = Default
• 1 = Danger
• 2 = Warning
• 3 = Success

---

KillFeedMessage

Property	Value
Packet ID	0xD5 (213)
Compressed	No
Fixed Block Size	1 bytes
Variable Field Count	3
Max Size	1600 MB
Nullable Bit Field	1 byte(s)
Variable Block Start	13

Fields

Name	Type	Offset	Size	Encoding	Nullable
killer	FormattedMessage	-1	var	nested:FormattedMessage	Yes
decedent	FormattedMessage	-1	var	nested:FormattedMessage	Yes
icon	String	-1	var	var_string:utf8	Yes

Layout Notes: Fixed block contains nullable bits at offset 0, offsets to variable data at offsets 1, 5, and 9 respectively. Variable data starts at byte 13.

---

ShowEventTitle

Property	Value
Packet ID	0xD6 (214)
Compressed	No
Fixed Block Size	14 bytes
Variable Field Count	3
Max Size	1600 MB
Nullable Bit Field	1 byte(s)
Variable Block Start	26

Fields

Name	Type	Offset	Size	Encoding	Nullable
fadeInDuration	float	1	4	float32_le	No
fadeOutDuration	float	5	4	float32_le	No
duration	float	9	4	float32_le	No
icon	String	-1	var	var_string:utf8	Yes
isMajor	boolean	13	1	byte	No
primaryTitle	FormattedMessage	-1	var	nested:FormattedMessage	Yes
secondaryTitle	FormattedMessage	-1	var	nested:FormattedMessage	Yes

Layout Notes: Fixed block contains nullable bits at offset 0, fixed float fields at offsets 1, 5, 9, and boolean at 13. Variable fields' offsets stored at offsets 14, 18, 22 respectively, relative to fixed block start.

---

HideEventTitle

Property	Value
Packet ID	0xD7 (215)
Compressed	No
Fixed Block Size	4 bytes
Variable Field Count	0
Max Size	4 bytes
Variable Block Start	4

Fields

Name	Type	Offset	Size	Encoding	Nullable
fadeOutDuration	float	0	4	float32_le	No

Layout Notes: Packet consists of a single fixed-size float field at offset 0, total size 4 bytes

---

SetPage

Property	Value
Packet ID	0xD8 (216)
Compressed	No
Fixed Block Size	2 bytes
Variable Field Count	0
Max Size	2 bytes
Variable Block Start	2

Fields

Name	Type	Offset	Size	Encoding	Nullable
page	Page	0	1	byte	No
canCloseThroughInteraction	boolean	1	1	byte	No

Layout Notes: Packet consists of 2 fixed bytes: page (byte) and canCloseThroughInteraction (byte). No nullable bits or variable fields.

page enum values:

• 0 = None
• 1 = Bench
• 2 = Inventory
• 3 = ToolsSettings
• 4 = Map
• 5 = MachinimaEditor
• 6 = ContentCreation
• 7 = Custom

---

CustomHud

Property	Value
Packet ID	0xD9 (217)
Compressed	Yes
Fixed Block Size	2 bytes
Variable Field Count	1
Max Size	1600 MB
Nullable Bit Field	1 byte(s)
Variable Block Start	2

Fields

Name	Type	Offset	Size	Encoding	Nullable
clear	boolean	1	1	byte	No
commands	CustomUICommand[]	-1	var	array:CustomUICommand	Yes

Layout Notes: Fixed block contains null bits at offset 0, boolean 'clear' at offset 1, commands array present if (nullBits & 0x1) != 0, variable data starts at offset + 2

---

CustomPage

Property	Value
Packet ID	0xDA (218)
Compressed	Yes
Fixed Block Size	4 bytes
Variable Field Count	3
Max Size	1600 MB
Nullable Bit Field	1 byte(s)
Variable Block Start	16

Fields

Name	Type	Offset	Size	Encoding	Nullable
key	String	-1	var	var_string:utf8	Yes
isInitial	boolean	1	1	byte	No
clear	boolean	2	1	byte	No
lifetime	CustomPageLifetime	3	1	byte	No
commands	CustomUICommand[]	-1	var	array:CustomUICommand	Yes
eventBindings	CustomUIEventBinding[]	-1	var	array:CustomUIEventBinding	Yes

Layout Notes: Fixed block contains 4 bytes: nullBits at offset 0, booleans at 1-2, lifetime at 3. Variable fields are stored in the variable section starting at offset 16, with offsets stored at fixed positions offset+4, offset+8, offset+12 respectively.

lifetime enum values:

• 0 = CantClose
• 1 = CanDismiss
• 2 = CanDismissOrCloseThroughInteraction

---

CustomPageEvent

Property	Value
Packet ID	0xDB (219)
Compressed	No
Fixed Block Size	2 bytes
Variable Field Count	1
Max Size	15.6 MB
Nullable Bit Field	1 byte(s)
Variable Block Start	2

Fields

Name	Type	Offset	Size	Encoding	Nullable
type	CustomPageEventType	1	1	byte	No
data	String	-1	var	var_string:utf8	Yes

Layout Notes: Fixed block contains nullable bits at offset 0, fixed field 'type' at offset 1, variable data offset and length handled within variable block starting at offset + 2

type enum values:

• 0 = Acknowledge
• 1 = Data
• 2 = Dismiss

---

EditorBlocksChange

Property	Value
Packet ID	0xDE (222)
Compressed	Yes
Fixed Block Size	30 bytes
Variable Field Count	2
Max Size	132.8 MB
Nullable Bit Field	1 byte(s)
Variable Block Start	38

Fields

Name	Type	Offset	Size	Encoding	Nullable
selection	EditorSelection	1	var	nested:EditorSelection	Yes
blocksChange	BlockChange[]	-1	var	array:BlockChange	Yes
fluidsChange	FluidChange[]	-1	var	array:FluidChange	Yes
blocksCount	int	25	4	int32_le	No
advancedPreview	boolean	29	1	byte	No

Layout Notes: Fixed block contains nullable bits at offset 0; fields at fixed offsets: selection at 1, blocksCount at 25, advancedPreview at 29; variable arrays at offsets determined by offsets stored at fixed positions (offset + 30 for blocksChange, offset + 34 for fluidsChange).

---

ServerInfo

Property	Value
Packet ID	0xDF (223)
Compressed	No
Fixed Block Size	5 bytes
Variable Field Count	2
Max Size	31.3 MB
Nullable Bit Field	1 byte(s)
Variable Block Start	13

Fields

Name	Type	Offset	Size	Encoding	Nullable
serverName	String	-1	var	var_string:utf8	Yes
motd	String	-1	var	var_string:utf8	Yes
maxPlayers	int	1	4	int32_le	No

Layout Notes: Fixed block contains nullBits at offset 0, maxPlayers at offset 1-4; variable data offsets stored at offset + 5 (serverName) and + 9 (motd)

---

AddToServerPlayerList

Property	Value
Packet ID	0xE0 (224)
Compressed	No
Fixed Block Size	1 bytes
Variable Field Count	1
Max Size	1600 MB
Nullable Bit Field	1 byte(s)
Variable Block Start	1

Fields

Name	Type	Offset	Size	Encoding	Nullable
players	ServerPlayerListPlayer[]	-1	var	nested:ServerPlayerListPlayer	Yes

Layout Notes: Fixed block contains 1 byte for null bits; if players array is present, variable data starts at offset 1, with offset to array data stored in the variable block

---

RemoveFromServerPlayerList

Property	Value
Packet ID	0xE1 (225)
Compressed	No
Fixed Block Size	1 bytes
Variable Field Count	1
Max Size	62.5 MB
Nullable Bit Field	1 byte(s)
Variable Block Start	1

Fields

Name	Type	Offset	Size	Encoding	Nullable
players	UUID[]	-1	var	array:nested:UUID	Yes

Layout Notes: Fixed block contains nullable bits at offset 0; variable data (UUID array) starts at offset 1, with offset determined by VarInt prefix for array length and UUIDs follow sequentially

---

UpdateServerPlayerList

Property	Value
Packet ID	0xE2 (226)
Compressed	No
Fixed Block Size	1 bytes
Variable Field Count	1
Max Size	125.0 MB
Nullable Bit Field	1 byte(s)
Variable Block Start	1

Fields

Name	Type	Offset	Size	Encoding	Nullable
players	ServerPlayerListUpdate[]	-1	var	nested:ServerPlayerListUpdate[]	Yes

Layout Notes: The fixed block contains a single nullable bit field at offset 0. If the bit is set, the variable section contains an array of ServerPlayerListUpdate objects. The array length is stored as a VarInt immediately after the null bits byte, followed by each ServerPlayerListUpdate serialized object. Each object’s size is determined by its own computeBytesConsumed method.

---

UpdateServerPlayerListPing

Property	Value
Packet ID	0xE3 (227)
Compressed	No
Fixed Block Size	1 bytes
Variable Field Count	1
Max Size	78.1 MB
Nullable Bit Field	1 byte(s)
Variable Block Start	1

Fields

Name	Type	Offset	Size	Encoding	Nullable
players	Map<UUID, Integer>	-1	var	nested:Map<UUID, Integer>	Yes

Layout Notes: Fixed block contains a single nullable bit flag at offset 0. If set, the variable section contains a count (VarInt) followed by UUID and Integer pairs for each player.

---

UpdateKnownRecipes

Property	Value
Packet ID	0xE4 (228)
Compressed	No
Fixed Block Size	1 bytes
Variable Field Count	1
Max Size	1600 MB
Nullable Bit Field	1 byte(s)
Variable Block Start	1

Fields

Name	Type	Offset	Size	Encoding	Nullable
known	Map<String, CraftingRecipe>	-1	var	nested:Map<String, CraftingRecipe>	Yes

Layout Notes: Fixed block contains nullable bits at offset 0; variable block starts at offset 1 and contains the map entries

---

UpdatePortal

Property	Value
Packet ID	0xE5 (229)
Compressed	No
Fixed Block Size	6 bytes
Variable Field Count	1
Max Size	15.6 MB
Nullable Bit Field	1 byte(s)
Variable Block Start	6

Fields

Name	Type	Offset	Size	Encoding	Nullable
state	PortalState	1	var	nested:PortalState	Yes
definition	PortalDef	-1	var	nested:PortalDef	Yes

Layout Notes: Fixed block contains nullable bits at offset 0; offset to 'definition' stored at fixed block start + 6; 'state' is directly after nullBits byte

---

UpdateVisibleHudComponents

Property	Value
Packet ID	0xE6 (230)
Compressed	No
Fixed Block Size	1 bytes
Variable Field Count	1
Max Size	3.9 MB
Nullable Bit Field	1 byte(s)
Variable Block Start	1

Fields

Name	Type	Offset	Size	Encoding	Nullable
visibleComponents	HudComponent[]	-1	var	array:HudComponent	Yes

Layout Notes: Fixed block contains nullable bits at offset 0. If the first bit (0x1) is set, then the variable section contains an array of HudComponent entries. The array length is stored as a VarInt immediately after the null bits byte, followed by that many 1-byte HudComponent entries.

---

ResetUserInterfaceState

Property	Value
Packet ID	0xE7 (231)
Compressed	No
Variable Field Count	0

---

UpdateLanguage

Property	Value
Packet ID	0xE8 (232)
Compressed	No
Fixed Block Size	1 bytes
Variable Field Count	1
Max Size	15.6 MB
Nullable Bit Field	1 byte(s)
Variable Block Start	1

Fields

Name	Type	Offset	Size	Encoding	Nullable
language	String	-1	var	var_string:utf8	Yes

Layout Notes: Fixed block contains nullable bits at offset 0. If language is present, it is stored as a variable-length UTF-8 string starting immediately after the null bits byte.

---

WorldSavingStatus

Property	Value
Packet ID	0xE9 (233)
Compressed	No
Fixed Block Size	1 bytes
Variable Field Count	0
Max Size	1 bytes
Variable Block Start	1

Fields

Name	Type	Offset	Size	Encoding	Nullable
isWorldSaving	boolean	0	1	byte	No

Layout Notes: Packet consists of a single boolean field at offset 0, total size 1 byte

---

OpenChatWithCommand

Property	Value
Packet ID	0xEA (234)
Compressed	No
Fixed Block Size	1 bytes
Variable Field Count	1
Max Size	15.6 MB
Nullable Bit Field	1 byte(s)
Variable Block Start	1

Fields

Name	Type	Offset	Size	Encoding	Nullable
command	String	-1	var	var_string:utf8	Yes

Layout Notes: Fixed block contains nullable bits at offset 0; variable data (command string) stored starting at offset 1, with offset pointer in variable block if needed (not used here).

---

Back to Home