Client-to-Server Inputs Reference

Overview

This is a comprehensive list of every packet a client can send to the server. The client sends abstract actions, not raw keyboard input. The server never sees "W pressed" - only the resulting movement states or action requests. This list is not exclusive to key inputs, but rather all packets.

Formatting is packet.flag, ie MovementStates.idle or ClientPlaceBlock.position

Data Structures

Enums vs Structs

Packets use two types of flag/value structures:

Type	Structure	Size	Serialization
Enum	Single value from fixed set	1 byte	Integer value of selected enum constant
Struct	Multiple fields sent together	Varies	Each field serialized sequentially

MovementStates (Struct)

Movement booleans.

Flag	Description
`idle`	Not moving
`walking`	Walking speed
`running`	Running speed
`sprinting`	Sprint speed
`jumping`	Currently jumping
`falling`	In freefall
`crouching`	Sneaking/crouched
`flying`	Creative flight
`onGround`	Touching ground
`inFluid`	In water/liquid
`swimming`	Swimming motion
`climbing`	On ladder/climbable
`gliding`	Using glider
`rolling`	Dodge roll
`sitting`	Seated
`sleeping`	In bed
`mounting`	Getting on mount
`mantling`	Climbing ledge
`sliding`	Sliding down slope
`horizontalIdle`	Not moving horizontally
`forcedCrouching`	Forced crouch (low ceiling)
`swimJumping`	Jumping while swimming

InteractionType (Enum)

Major interactions.

Value	Name	Player Input	Description
0	`Primary`	LMB	Primary action - attack, break block
1	`Secondary`	RMB	Secondary action - use item, place block
2	`Ability1`	Q	Weapon/item ability
3	`Ability2`	—	Reserved (no default binding)
4	`Ability3`	—	Reserved (no default binding)
5	`Use`	E	World interaction - containers, NPCs
6	`Pick`	MMB	Pick block
7	`Pickup`	—	Item pickup (system)
8	`CollisionEnter`	—	Collision started (system)
9	`CollisionLeave`	—	Collision ended (system)
10	`Collision`	—	Ongoing collision (system)
11	`EntityStatEffect`	—	Stat effect applied (system)
12	`SwapTo`	—	Item swapped to (system)
13	`SwapFrom`	—	Item swapped from (system)
14	`Death`	—	Entity death (system)
15	`Wielding`	—	Wielding state (system)
16	`ProjectileSpawn`	—	Projectile spawned (system)
17	`ProjectileHit`	—	Projectile hit (system)
18	`ProjectileMiss`	—	Projectile missed (system)
19	`ProjectileBounce`	—	Projectile bounced (system)
20	`Held`	—	Item held (system)
21	`HeldOffhand`	—	Item held offhand (system)
22	`Equipped`	—	Item equipped (system)
23	`Dodge`	—	Dodge roll action
24	`GameModeSwap`	—	Game mode changed (system)

BuilderToolAction (Enum)

Builder tool general actions.

Value	Name	Default Key	Description
0	`SelectionPosition1`	—	Set first corner of selection
1	`SelectionPosition2`	—	Set second corner of selection
2	`SelectionCopy`	Ctrl+C	Copy selection to clipboard
3	`HistoryUndo`	Ctrl+Z	Undo last operation
4	`HistoryRedo`	Ctrl+Y	Redo last undone operation
5	`ActivateToolMode`	B	Enter builder tool mode
6	`DeactivateToolMode`	B	Exit builder tool mode

InventoryActionType (Enum)

Bulk inventory operations.

Value	Name	Description
0	`TakeAll`	Take all items from container to inventory
1	`PutAll`	Put all matching items into container
2	`QuickStack`	Quick stack matching items into container
3	`Sort`	Sort container (actionData specifies sort type)

CustomPageEventType (Enum)

3 values for custom UI page events.

Value	Name	Description
0	`Acknowledge`	Client acknowledging page action
1	`Data`	Client sending data back to server
2	`Dismiss`	Client dismissed/closed page

Key → Packet Reference

Summary of all default Key Mappings.

Key	Packet	Package	Notes
W/A/S/D	`ClientMovement`	player	Movement states in packet
Space	`ClientMovement`	player	`jumping` state
Shift	`ClientMovement`	player	`crouching` state
Shift (mounted)	`DismountNPC`	interaction	When riding a mount
LMB	`MouseInteraction`	player	`Primary` (0)
RMB	`MouseInteraction`	player	`Secondary` (1)
Q	`MouseInteraction`	player	`Ability1` (2)
Q (hold)	`DropItemStack`	inventory	When holding item
E	`MouseInteraction`	player	`Use` (5)
MMB	`MouseInteraction`	player	`Pick` (6)
1-9	`SetActiveSlot`	inventory	Direct slot selection
Scroll	`SetActiveSlot`	inventory	Hotbar scrolling
Scroll (on block)	`SwitchHotbarBlockSet`	inventory	Block variant cycling
M	`UpdateWorldMapVisible`	worldmap	Map toggle
B	`BuilderToolGeneralAction`	buildertools	`ActivateToolMode` (5) / `DeactivateToolMode` (6)
Ctrl+C	`BuilderToolGeneralAction`	buildertools	`SelectionCopy` (2)
Ctrl+Z	`BuilderToolGeneralAction`	buildertools	`HistoryUndo` (3)
Ctrl+Y	`BuilderToolGeneralAction`	buildertools	`HistoryRedo` (4)
ESC	`SetPaused`	world	Singleplayer only
ESC (window open)	`CloseWindow`	window	Closes active window
Enter	`ChatMessage`	interface_	Sends chat/command

Player

Core player action packets. These are the most commonly used packets for gameplay logic - combat systems, custom abilities, movement validation, and interaction handling.

Packet	ID	Fields	Description
`ClientMovement`	100	`absolutePosition`, `relativePosition`, `movementStates`, `bodyOrientation`, `lookOrientation`, `velocity`, `wishMovement`, `teleportAck`	Continuous position/rotation updates. Contains either absolute position or relative delta. `teleportAck` confirms server teleports. Uses `MovementStates` struct.
`MouseInteraction`	22	`interactionType`, `targetEntity`, `targetBlock`, `screenPoint`	Mouse button actions with target information. Uses `InteractionType` enum.
`ClientPlaceBlock`	104	`position`, `rotation`, `placedBlockId`	Client placing a block. Contains position, rotation, and the specific block variant being placed.
`ClientReady`	105	`readyForChunks`, `readyForGameplay`	Client signaling ready state. `readyForChunks` = ready to receive world data, `readyForGameplay` = fully loaded.
`SyncPlayerPreferences`	116	`showEntityMarkers`, `armorItemsPreferredPickupLocation`, `weaponAndToolItemsPreferredPickupLocation`, `usableItemsItemsPreferredPickupLocation`, `solidBlockItemsPreferredPickupLocation`, `miscItemsPreferredPickupLocation`, `allowNPCDetection`, `respondToHit`	Client syncing player settings to server. Includes item pickup preferences and UI settings.
`LoadHotbar`	180	`index`	Load a saved hotbar preset by index.
`SaveHotbar`	181	`index`	Save current hotbar to preset slot.

Inventory

Item and slot management packets. Useful for custom inventory rules, item restrictions, ability triggers via hotbar slots, and tracking player item usage.

Packet	ID	Fields	Description
`SetActiveSlot`	177	`inventorySectionId`, `activeSlot`	Player changing active hotbar slot via keys 1-9 or scroll wheel.
`MoveItemStack`	175	`fromSectionId`, `fromSlotId`, `quantity`, `toSectionId`, `toSlotId`	Dragging item from one slot to another.
`SmartMoveItemStack`	176	`fromSectionId`, `fromSlotId`, `quantity`, `moveType`	Shift-click auto-move. `moveType` determines destination logic.
`DropItemStack`	174	`inventorySectionId`, `slotId`, `quantity`	Dropping item from inventory. Triggered by Q key (hold).
`SwitchHotbarBlockSet`	178	`itemId`	Cycling through block variants using scroll wheel while holding a block item.
`InventoryAction`	179	`inventorySectionId`, `inventoryActionType`, `actionData`	Bulk inventory operations from UI buttons. Uses `InventoryActionType` enum.
`SetCreativeItem`	171	`inventorySectionId`, `slotId`, `item`, `override`	Set/spawn item in creative inventory. `override` determines if existing item is replaced.
`DropCreativeItem`	172	`item`	Drop item spawned from creative menu into world.
`SmartGiveCreativeItem`	173	`item`, `moveType`	Auto-place creative item (equip armor, add to hotbar, etc).

Interaction

Combat and entity interaction sync packets. Used for combat validation, combo systems, mount control, and NPC interaction tracking.

Packet	ID	Fields	Description
`SyncInteractionChains`	290	`updates[]`	Synchronizes ongoing attack/ability chains between client and server for animation and hit detection.
`DismountNPC`	294	—	Player requesting to dismount. Triggered by Shift key while mounted.

Interface

Chat, language, and custom UI packets. Essential for command systems, chat moderation, custom menus, shops, dialogs, and any server-driven UI.

Packet	ID	Fields	Description
`ChatMessage`	211	`message`	Player chat message or command. Messages starting with `/` are processed as commands. Messages starting with `.` (local commands) are rejected by server.
`UpdateLanguage`	212	`language`	Player changed language preference.
`CustomPageEvent`	219	`type`, `data`	Response to server-defined custom UI page. Uses `CustomPageEventType` enum. `data` is optional string payload (max 4MB).

Window

Container and window management packets. Useful for custom container logic, crafting systems, trading interfaces, and tracking when players open/close menus.

Packet	ID	Fields	Description
`ClientOpenWindow`	200	`type`	Client requesting to open a window. Only certain window types are client-requestable.
`SendWindowAction`	201	`id`, `action`	Client sending an action/interaction to an open window.
`CloseWindow`	202	`id`	Client closing a window (ESC key or close button).

Worldmap

Map visibility and navigation packets. Can be used as an extra keybind (M key detection), custom map overlays, teleportation systems, or death marker tracking.

Packet	ID	Fields	Description
`UpdateWorldMapVisible`	243	`visible`	Player opened or closed world map. Toggled by M key.
`RemoveMapMarker`	246	`markerId`	Remove a marker from the map (death markers, custom markers).
`TeleportToWorldMapMarker`	244	`id`	Request teleport to a map marker. Requires `allowTeleportToMarkers` permission.
`TeleportToWorldMapPosition`	245	`x`, `y`	Request teleport to map coordinates. Requires `allowTeleportToCoordinates` permission.

Entities

Entity-related movement packets. Used for custom mount physics, mount-specific abilities, or vehicle control systems.

Packet	ID	Fields	Description
`MountMovement`	166	`absolutePosition`, `bodyOrientation`, `movementStates`	Position and movement states for the mount entity when player is riding.

Camera

Camera control packets. Useful for spectator systems, cinematic sequences, or admin observation tools.

Packet	ID	Fields	Description
`RequestFlyCameraMode`	282	`entering`	Request to enter or exit fly camera mode. Requires `hytale.flyCam` permission.

Buildertools

Creative mode building tool packets. Requires hytale.editor.builderTools permission. Can be granted to non-creative players to enable these packets as extra keybinds (B, Ctrl+Z/Y/C), or used to track/validate creative building operations.

General Actions

Packet	ID	Fields	Description
`BuilderToolGeneralAction`	412	`action`	General builder tool action. Uses `BuilderToolAction` enum.

Entity Manipulation

Packet	ID	Fields	Description
`BuilderToolEntityAction`	401	`entityId`, `action`	Entity tool action (Freeze, Clone, Remove).
`BuilderToolSetEntityTransform`	402	`entityId`, `position`, `rotation`	Set entity position and rotation.
`BuilderToolSetEntityScale`	420	`entityId`, `scale`	Set entity scale.
`BuilderToolSetEntityLight`	422	`entityId`, `light`	Set entity light properties.
`BuilderToolSetEntityPickupEnabled`	421	`entityId`, `enabled`	Toggle whether entity can be picked up.
`BuilderToolSetNPCDebug`	423	`entityId`, `debug`	Toggle NPC debug mode.

Selection Tools

Packet	ID	Fields	Description
`BuilderToolSelectionUpdate`	409	`selection`	Update selection bounds.
`BuilderToolSelectionTransform`	405	`transform`	Transform (move/rotate) current selection.
`BuilderToolSelectionToolAskForClipboard`	410	—	Request clipboard data from server.

Block Operations

Packet	ID	Fields	Description
`BuilderToolExtrudeAction`	403	`axis`, `amount`	Extrude selection along axis.
`BuilderToolLineAction`	414	`start`, `end`	Draw a line of blocks between two points.
`BuilderToolStackArea`	404	`count`, `offset`	Stack/repeat selection multiple times.

Clipboard

Packet	ID	Fields	Description
`BuilderToolRotateClipboard`	406	`axis`, `direction`	Rotate clipboard contents.
`BuilderToolPasteClipboard`	407	`position`, `options`	Paste clipboard at position.

Tool Configuration

Packet	ID	Fields	Description
`BuilderToolArgUpdate`	400	`toolId`, `args`	Update tool-specific arguments/settings.
`BuilderToolSetTransformationModeState`	408	`mode`	Set transformation mode (move/rotate/scale).
`BuilderToolOnUseInteraction`	413	`position`, `block`	Tool use interaction at position.

Prefab

Packet	ID	Fields	Description
`PrefabUnselectPrefab`	417	—	Deselect currently selected prefab.

Machinima

Cinematic/machinima system packets. Used for in-game cinematics, cutscenes, or replay systems.

Packet	ID	Fields	Description
`RequestMachinimaActorModel`	260	`modelId`, `sceneName`, `actorName`	Request a model for use in machinima scene.
`UpdateMachinimaScene`	261	`player`, `sceneName`, `frame`, `updateType`, `scene`	Update machinima scene state. Can target specific player or broadcast with `*`.

Connection

Initial connection handshake packets. Used for custom connection validation, protocol checks, or connection-time logging.

Packet	ID	Fields	Description
`Connect`	0	`protocolHash`, `language`, `uuid`, `username`, `clientType`	First packet sent. Contains protocol version for compatibility check, player identity, and client type.
`Disconnect`	1	`type`, `reason`	Client notifying server it's disconnecting. Type indicates reason category (quit, timeout, kicked, etc).
`Pong`	3	`timestamp`	Response to server Ping for latency measurement and keepalive.

Auth

Authentication packets. Used during the connection handshake for secure servers or password-protected servers.

Packet	ID	Fields	Description
`AuthToken`	12	`token`, `nonce`	Client's authentication token for secure servers. Part of mutual auth handshake.
`PasswordResponse`	15	`password`	Client's response to server password prompt.

Setup

Initial setup phase packets. Sent after connection but before gameplay. Used for enforcing render distance limits, tracking client capabilities, or custom loading logic.

Packet	ID	Fields	Description
`RequestAssets`	23	`assets[]`	Client requesting specific assets (textures, models, sounds) from the server. Array of asset identifiers.
`ViewRadius`	32	`value`	Client's requested view/render distance in blocks. Server may clamp this.
`PlayerOptions`	33	`skinData`, `preferences`	Player cosmetics and client preferences sent during setup.

World

World state packets. The pause packet only functions in singleplayer.

Packet	ID	Fields	Description
`SetPaused`	158	`paused`	Pause/unpause game. Only processed in singleplayer with one player.

Serveraccess

LAN/server access configuration packets. Only functional for singleplayer world owners configuring LAN access.

Packet	ID	Fields	Description
`UpdateServerAccess`	251	`hosts[]`, `access`	Update LAN server visibility settings. Singleplayer owner only.
`SetServerAccess`	252	`access`, `password`	Set LAN access mode and password. Singleplayer owner only.

Server Events

Packets with corresponding server-side events:

Packet	Package	Event	Cancellable
`MouseInteraction`	player	`PlayerInteractEvent`	Yes
`SetActiveSlot`	inventory	`SwitchActiveSlotEvent`	Yes
`DropItemStack`	inventory	`DropItemEvent.PlayerRequest`	Yes
`ChatMessage`	interface_	`PlayerChatEvent`	Yes
`Connect`	connection	`PlayerSetupConnectEvent`	Yes
`Disconnect`	connection	`PlayerDisconnectEvent`	No
`ClientReady`	player	`PlayerReadyEvent`	No

Imports

// player
import com.hypixel.hytale.protocol.packets.player.ClientMovement;
import com.hypixel.hytale.protocol.packets.player.MouseInteraction;
import com.hypixel.hytale.protocol.packets.player.ClientPlaceBlock;
import com.hypixel.hytale.protocol.packets.player.ClientReady;
import com.hypixel.hytale.protocol.packets.player.SyncPlayerPreferences;
import com.hypixel.hytale.protocol.packets.player.LoadHotbar;
import com.hypixel.hytale.protocol.packets.player.SaveHotbar;

// inventory
import com.hypixel.hytale.protocol.packets.inventory.SetActiveSlot;
import com.hypixel.hytale.protocol.packets.inventory.MoveItemStack;
import com.hypixel.hytale.protocol.packets.inventory.SmartMoveItemStack;
import com.hypixel.hytale.protocol.packets.inventory.DropItemStack;
import com.hypixel.hytale.protocol.packets.inventory.SwitchHotbarBlockSet;
import com.hypixel.hytale.protocol.packets.inventory.InventoryAction;
import com.hypixel.hytale.protocol.packets.inventory.SetCreativeItem;
import com.hypixel.hytale.protocol.packets.inventory.DropCreativeItem;
import com.hypixel.hytale.protocol.packets.inventory.SmartGiveCreativeItem;

// interaction
import com.hypixel.hytale.protocol.packets.interaction.SyncInteractionChains;
import com.hypixel.hytale.protocol.packets.interaction.DismountNPC;

// interface_
import com.hypixel.hytale.protocol.packets.interface_.ChatMessage;
import com.hypixel.hytale.protocol.packets.interface_.UpdateLanguage;
import com.hypixel.hytale.protocol.packets.interface_.CustomPageEvent;

// window
import com.hypixel.hytale.protocol.packets.window.ClientOpenWindow;
import com.hypixel.hytale.protocol.packets.window.SendWindowAction;
import com.hypixel.hytale.protocol.packets.window.CloseWindow;

// worldmap
import com.hypixel.hytale.protocol.packets.worldmap.UpdateWorldMapVisible;
import com.hypixel.hytale.protocol.packets.worldmap.RemoveMapMarker;
import com.hypixel.hytale.protocol.packets.worldmap.TeleportToWorldMapMarker;
import com.hypixel.hytale.protocol.packets.worldmap.TeleportToWorldMapPosition;

// entities
import com.hypixel.hytale.protocol.packets.entities.MountMovement;

// camera
import com.hypixel.hytale.protocol.packets.camera.RequestFlyCameraMode;

// buildertools
import com.hypixel.hytale.protocol.packets.buildertools.*;

// machinima
import com.hypixel.hytale.protocol.packets.machinima.RequestMachinimaActorModel;
import com.hypixel.hytale.protocol.packets.machinima.UpdateMachinimaScene;

// connection
import com.hypixel.hytale.protocol.packets.connection.Connect;
import com.hypixel.hytale.protocol.packets.connection.Disconnect;
import com.hypixel.hy

From Hytale Server build 2026.01.13-dcad8778f

Client-to-Server Inputs Reference

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