UI-Utils

Fabric mod for debugging server GUIs and packets. Supports Minecraft 1.21 - 1.21.11.

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Screenshots

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Credits

Role	Author	Link
Original Creator	Coderx-Gamer	GitHub
Modified by	FrannnDev	GitHub

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Downloads

Minecraft	Download
1.21	ui_utils-2.4.1-mc1.21.jar
1.21.1	ui_utils-2.4.1-mc1.21.1.jar
1.21.2	ui_utils-2.4.1-mc1.21.2.jar
1.21.3	ui_utils-2.4.1-mc1.21.3.jar
1.21.4	ui_utils-2.4.1-mc1.21.4.jar
1.21.5	ui_utils-2.4.1-mc1.21.5.jar
1.21.6	ui_utils-2.4.1-mc1.21.6.jar
1.21.7	ui_utils-2.4.1-mc1.21.7.jar
1.21.8	ui_utils-2.4.1-mc1.21.8.jar
1.21.11	ui_utils-2.4.1-mc1.21.11.jar

Note: Versions 1.21.9-1.21.10 are not yet supported due to incomplete Fabric yarn mappings.

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Installation

1. Install Fabric Loader
2. Drop the mod JAR into your mods folder (Fabric API is already included)
3. (Optional) Install ViaFabricPlus for multi-version support

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Inventory Overlay (E Menu)

Open any inventory to see the UI-Utils overlay on the left side.

Info Panel

Located at the top-right of the overlay:

Field	Description
Sync	Current screen handler sync ID used by packets
Rev	Current revision number for packet validation

Button List

Button	Description
Close without packet	Closes GUI client-side only. Server thinks GUI is still open
Desync	Sends close packet to server but keeps GUI open client-side
Send packets: true/false	Toggle whether click packets are sent to server
Delay packets: true/false	When ON, stores all click packets in queue instead of sending
Leave & Send Packets	Sends all queued packets at once, then closes GUI
Fabricate packet	Opens external window to create custom packets (not available on Mac)
Copy GUI Title JSON	Copies current GUI title as JSON to clipboard
Save GUI / Load GUI	Save current GUI state to memory or restore it
Clear Queue / Queue: N	Clear all queued packets or show current queue count
Resync Inv / Disconnect	Force inventory resync or disconnect from server
[-] Spam (xN) [+]	Send all queued packets N times. Use - and + to adjust multiplier
Send One / Pop Last	Send first packet from queue or remove last packet without sending

Chat Input

At the bottom-left of any GUI there is a chat input field:

• Type messages --> sends to server chat
• Start with / --> sends as server command
• Start with , --> executes UI-Utils command

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Multiplayer Screen

Custom buttons appear at the top of the multiplayer server list.

Left Side - Resource Pack

Button	Description
Bypass	Bypass required resource packs. Tells server pack was loaded without downloading. Green when active
Deny	Force deny all resource packs. Use if Bypass alone still kicks you. Green when active

Right Side - Utilities

Button	Description
User	Opens popup to change session username. Temporary until game restart
Via+	Opens ViaFabricPlus version selector. Requires ViaFabricPlus mod installed

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Keybinds

Key	Action
V	Load saved GUI (configurable in controls menu)

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Commands

All commands use , prefix by default. Change with ,prefix <new>.

General

Command	Usage	Description
help	,help [command]	List all commands or show help for specific command
man	,man <command>	Show detailed manual for a command
toggleuiutils	,toggleuiutils	Toggle UI-Utils overlay on/off
prefix	,prefix [new]	View or change command prefix
echo	,echo <text>	Print text to chat (client-side only)

Math

Command	Usage	Description
math	,math <expression>	Calculate math expression. Supports + - * / ^ ()

Example:

,math 2+2*3
--> Result: 8.0

Screen Control

Command	Usage	Description
close	,close	Close current screen without sending packet
desync	,desync	Send close packet but keep GUI open client-side

Chat

Command	Usage	Description
chat	,chat <message>	Send message or command to server from anywhere

Example:

,chat /spawn
--> Sends /spawn command to server

Server

Command	Usage	Description
joinserver	,joinserver <ip[:port]>	Connect to another server
plugins	,plugins	Scan server plugins via tab-complete exploit

Plugins output:

• Normal plugins --> red text
• Anticheats/exploit-related --> dark red text

Screen Management

Command	Usage	Description
screen save	,screen save <slot>	Save current screen to named slot
screen load	,screen load <slot>	Load saved screen from slot
screen list	,screen list	List all saved screen slots
screen info	,screen info <slot>	Show info about saved screen

Account

Command	Usage	Description
account dump	,account dump	Show current username and UUID
account set username	,account set username <name>	Change session username
account set uuid	,account set uuid <uuid>	Change session UUID

Note: Account changes are temporary and reset on game restart.

Movement

Command	Usage	Description
vclip	,vclip <blocks>	Teleport vertically. Positive = up, negative = down
hclip	,hclip <blocks>	Teleport horizontally in look direction

Examples:

,vclip 5
--> Teleport 5 blocks up

,vclip -3
--> Teleport 3 blocks down

,hclip 10
--> Teleport 10 blocks forward

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Fabricate Packet

External window for creating custom packets.

ClickSlotC2SPacket

Used for clicking slots in GUIs.

Field	Description
Sync Id	From overlay info panel
Revision	From overlay info panel
Slot	Slot number to click (starts at 0)
Button	0 = left click, 1 = right click, 0-8 = hotbar slot, 40 = offhand
Action	PICKUP, QUICK_MOVE, SWAP, CLONE, THROW, QUICK_CRAFT, PICKUP_ALL
Times to send	Number of packets to send
Delay	Check to add packet to delay queue instead of sending

ButtonClickC2SPacket

Used for clicking buttons in server GUIs (enchantment tables, stonecutters, etc).

Field	Description
Sync Id	From overlay info panel
Button Id	Button number to click (starts at 0)
Times to send	Number of packets to send
Delay	Check to add packet to delay queue instead of sending

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Toggle

Type ,toggleuiutils in chat or any GUI chat input to enable or disable the mod overlay.

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Building

Single Version

.\gradlew build

All Versions

.\build-all.bat

Output JARs will be in build/libs/ (single) or releases (all versions).

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License

This mod is licensed under CC BY-NC-SA 4.0. See LICENSE file.