UI-Utils 26x CevAPI

Overview

• This is a rewrite of the original UI-Utils 2.4.0, migrated to Mojang mappings (mojmap) which was ported out of Wurst-7-CevAPI and then bumped to Minecraft 26.x and put into a standalone mod.
• On top of classic UI-Utils quality-of-life features, this build adds advanced packet tooling, command scanning, macros, auto-duping and expanded UI controls.
• This application is designed and presented for people already familiar with UI-Utils. There will be no explanations or guide on how to use it in-game, you can instead find that here.
• If you are looking for a 1.21.11 version you can find that here but it will not have the majority of features in this project.

Build

Build with Gradle (Java 25+):

./gradlew clean build

Artifacts land in build/libs/. The artifact version comes from mod_version and release_version in gradle.properties.

The default build targets Minecraft 26.1, the oldest supported release, so compilation catches accidental use of newer-only APIs. The resulting jar is designed to run across Minecraft 26.1 through 26.3; runtime shims cover API changes introduced in later supported 26.x releases. To compile specifically against Minecraft 26.3, override the versions at build time:

./gradlew build -Pminecraft_version=26.3 -Pfabric_version=0.160.6+26.3 -Ploader_version=0.19.5

The macro file picker runs inside Minecraft and needs no optional native dialog library. New macro bindings store key names so they survive the GLFW-to-SDL change in 26.3; older macros containing only numeric bindings may need rebinding when moved between input systems.

Getting Started

1. Install Fabric Loader and Fabric API for your Minecraft 26.1–26.3 installation.
2. Drop the built jar from build/libs/ into your mods/ folder.
3. Launch Minecraft. Open any container — the UI‑Utils toolbox appears on the left.

Highlights

Update Checker

• On launch the mod checks the GitHub releases for a newer version
• Runs on a background thread with a 5 second timeout, so a slow or offline network never delays the game
• If an update exists it is announced once per game launch with a clickable link to the release page; it is not repeated when you change servers or worlds

Simple GUI

• Close GUI without sending a packet
• De‑sync tricks (close packet only)
• Send/Delay queue for UI packets, with flush on demand
• Disconnect & send (flushes every queued GUI packet, then disconnects)

GUI Tools (saved-GUI lifecycle)

• Its own draggable in-game panel (drag by the grip in the panel's top-right corner)
• Appears on container and inventory screens only (chests, plugin GUIs, player inventory, creative inventory); chat, the pause menu, options, level loading during a portal transition and other mods' screens never host it
• Defaults to the right of the container and stacks below the fabrication panel when both are open
• Save / Load / Clear GUI Cache so a stored screen never lingers after it is stale
• Tracks the saved Screen, its ScreenHandler, the GUI name, sync ID and revision
• Reports whether the saved GUI is still LIVE (server-backed) or has become STALE (clientside-only) after the server closed the window
• Shows the same LIVE / CLIENT-ONLY state for the currently open GUI right next to the fabrication tools
• Copy GUI JSON serializes the whole GUI (title components, syncId, revision, saved-GUI state, cursor and every occupied slot with item id, count and full data-component/NBT representation) as pretty JSON to the clipboard
• Copy Title JSON keeps the old title-only behaviour
• Steal moves the container contents into your inventory, Store moves your inventory into the container, Dump throws the container contents on the ground
• Transfers are queued at a configurable delay (default 100 ms) instead of firing every click at once, so servers do not reject or throttle them
• Open from the UI‑Utils overlay (GUI Tools) or via .uiutils gui tools

Container buttons (Steal / Store / Dump)

• Small vanilla-styled buttons (44x12) shown centred above any open container GUI, so they match the active resource pack
• Gated by the Steal/Store/Dump buttons option in Settings
• Steal quick-moves every container slot into your inventory
• Store quick-moves your inventory into the container
• Dump throws the container contents on the ground
• Transfers run as a queue at the configurable transfer delay (adjustable in GUI Tools)
• Hidden in the player inventory and the creative inventory

GUI Packet Logger

• Focused logger for container traffic only, normalized to one row format: timestamp | direction | packet | syncId | revision | slot | button | action | cursor/item
• Covers ClickSlot, ButtonClick, CloseScreen, CreativeSlot, SetSlot, SetContent, SetData, Cursor, OpenScreen and CloseScreen
• Bounded in-memory ring buffer plus an optional config/packet-logger/gui-<timestamp>.log file (batched writes, flushed from the client tick)
• Scrollable viewer that scales its width with the window size so the long rows stay readable
• Open from GUI Tools, from the overlay (GUI Packet Log) or via .uiutils guilog open

Per-Packet GUI Delay / Block (GUI Packet Control)

• Replaces the old all-or-nothing handling for GUI packets with a rule per packet class
• Rules: Allow / Drop / Delay, each packet coloured by its state
• Covers Click Slot, Button Click, Close Screen, Creative Slot, Slot State, Held Slot, Place Recipe, Select Trade, Set Beacon, Sign Update, Recipe Book and Recipe Seen
• Delay is tick based and shared with the existing queue, so Clear Queue, Spam, Send One, Pop Last and Disconnect & Send Packets all work with it
• Rules persist in ui-utils.json
• Open from GUI Tools or via .uiutils guipackets screen

Packet Fabrication Helpers (ClickSlot, ButtonClick, Timed Spam)

• Its own titled, draggable in-game panel (drag by the grip in the panel's top-right corner)
• Appears on container and inventory screens only, same as GUI Tools
• Toggling it from anywhere else is remembered and the panel shows as soon as a container or the inventory is open
• Header shows the GUI name, live syncId / revision and LIVE / CLIENT-ONLY state, plus the saved-GUI status
• Action dropdown for PICKUP, QUICK_MOVE, SWAP, CLONE, THROW, QUICK_CRAFT, PICKUP_ALL instead of cycling blindly
• Captured default sync ID / revision, editable per send
• Repeat count per send plus a delay toggle
• Validation and status feedback (out-of-range slots, non-numeric fields, send summaries) under the send button
• Quick Steal / Dump / Copy JSON buttons for the open container
• Timed Spam mode: send a chosen slot click N times with a configurable millisecond interval for race / desync testing (for example slot 5, 40 clicks, 50 ms apart), with live progress
• The overlay widgets are re-created on resize, so the fabricator no longer goes missing after a window resize

Command, Plugin, and Server Scanner

• Passively caches joined-server packet evidence (configuration, known packs, payload channels, registries, dimensions, advancements, tab/scoreboard text, and chat-completion metadata) per connected server. Server-list/status traffic is excluded.
• Command scans offer two modes:
  • Packet probes command suggestions and can discover roots beyond the immediately visible command list.
  • Client recursively enumerates non-vanilla paths from the server-synced Brigadier command tree, including literal subcommands, argument paths, and redirect/alias branches, without sending probe packets. Vanilla/default commands and Essentials commands/aliases are omitted, matching the scanner's existing filters.
• Packet-discovered roots that are absent from the current player's synced command tree are highlighted red: they are permission-hidden for that player and should not be assumed executable.
• Discovered command rows are clickable. Selecting one fills the packet-command field; execution still requires the explicit Send packet cmds button.
• After a manual packet-command send, a temporary output panel records the sent command and system command responses. It does not capture player chat.
• Supports packet execution of selected/manual commands, optional execution of discovered commands, and trigger value discovery (logged as trigger (value)).
• Plugin results merge packet evidence, known packs, custom payloads, command-tree roots, plugin-list evidence, and root hints. Expand plugin rows for associated commands and cached server evidence.
• A Verbose Server Scan combines the current server fingerprint with plugin and command scans, starting missing scans for the current server when needed. Its report is scrollable and copyable.
• Completed plugin, command, and verbose scans are stored as compact per-server JSON history under <gameDir>/config/ui-utils-scan-history/. Each scan overwrites its latest snapshot and records only added, removed, changed, or unchanged findings to avoid unbounded duplicate logs.
• Supports parsing plugins for vulnerabilities pursuant to the latest cache of DupeDB.

AntiCheat Detector

• Reads packets on server join to determine the current AntiCheat, if any.
• Disable/Enable in settings.

Extra Tools From FrannnnDev's fork of UI-Utils

• Leave & send, Disconnect & send, Save/Load GUI, Clear Queue, Queue, Resync Inv, Disconnect, Spam +/-, Send One, Pop Last
• Queue helper and counter
• .uiutils commands
• Named GUI slot maps
• Plugin scanner

Advanced Packet Tool (APT)

• Lets you manage packet behavior per packet type (S2C & C2S)
• Supports 3 independent modes: Log, Deny and Delay
• Modes can overlap (Log & Deny Packet A but also Log & Delay Packet B)
• Toggles for enabling modes as well as cycling through packet edit list
• Delay is tick based
• Searchable dual-list UI with select all/none controls
• Runs entirely in-game, with the full control set on one screen (modes, output, packet selection and delay)
• Optional Show Unknown Packets feature to allow class_#### packets
• Verbose mode dumps monitored packets with full per-field detail, including recursively expanded packet bundles
• Detailed decoding for item stacks and their data components, block states, registries and data values where available
• Decode coverage tracking reports which packet types are fully decoded, partially decoded or reflection-only
• Entity lifecycle tracking correlates spawn, motion, teleport, metadata, equipment and removal packets
• Batched log writes with a configurable flush interval, written as JSONL alongside an optional human-readable log
• Enabling logging reports the monitored type counts and log location to chat
• Inspired by HelixCraft's Packet Logger
• Open from the UI‑Utils overlay, by keybind (configurable in Settings) or via .uiutils apt

Macro System (Beta)

• A macro is a named automation script made of ordered steps (actions and wait conditions).
• The Macro Library provides Create New, Edit Selected, Delete Selected, Run Selected and Stop, plus import/export fields.
• Macros can be saved, edited, duplicated, reordered, deleted, exported and imported.
• Actions include SEND_CHAT and SEND_COMMAND; a leading / in SEND_CHAT is routed as a command.
• The macro editor supports:
  • Add Action and Add Conditional pickers
  • Per-step controls: move up/down, duplicate, edit, delete
  • Scrollable step list with draggable scrollbar
  • Undo/redo for editor changes
  • Loop toggle, plus Once (temporary) and Run (saved macro)
  • Optional keybind assignment per macro
• The step options screen supports:
  • Context-aware fields per action type
  • Compact layout for simple actions
  • Multi-value list fields (comma-separated input + Add/Clear)
  • No empty editor for actions with no configurable options (for example STOP_MACRO)
• Runtime behavior:
  • Macros execute steps in order
  • WAIT_* conditions pause progression until matched (or timeout depending on the condition)
  • STOP_MACRO terminates execution immediately
• Import/export:
  • Import reads .nbt macro files
  • Export accepts a folder path and writes <macro-name>.nbt
  • Native pickers are available from ... buttons
  • Default directories are auto-created:
    • <gameDir>/config/ui-utils/macro_import
    • <gameDir>/config/ui-utils/macro_export

Autoduper (Beta)

• Uses a strategy matrix built from 218+ different methodologies inspired by DupeDB
• Accepts a plugin GUI open command plus an optional prepare command, so it can work with plugin inventory GUIs such as /pv 1, /ec, /ah, or /shop
• Player-inventory target slots are treated as seed items for plugin GUI lifecycles, not as a vanilla inventory dupe scan
• Per-category toggles let you narrow the run instead of running everything:
  • Movement methods
  • Close methods
  • Reopen methods
  • Packet-delay variants
  • Validation
• Start from the main UI-Utils overlay or from the Autoduper options screen while a container is open
• Includes exact attempt replay, a visible abort overlay and a hold-to-abort key
• Success messages report the exact attempt number for easy replay
• Verbose mode toggle to find niche dupes even when similar attempts failed

Expanded Settings Screen

• Tri‑state Slot Overlay: OFF / HOVER / ALWAYS
• Unified HSV color picker with target selector:
  • Button background color
  • Button text color
  • Overlay number color
  • Packet HUD text color
• Overlay alpha and XY offsets
• Resource-pack bypass and force-deny options, plus an optional registry-sync workaround
• When “Show resource pack buttons” is enabled, these three options also appear as checkboxes near the bottom-left of the Multiplayer screen
• The bypass accepts required server-pack requests and reports them as loaded without downloading or applying the pack. Force deny instead declines intercepted requests; it only takes effect while the bypass option is enabled.
• Ignore registry sync filters unknown entries before Fabric remaps the server registry data. Unknown mob effects get inert placeholders to help preserve raw-ID alignment; other unknown registry data is left unsynced and reported in the log.
• Close Delay and Command Delay sliders (tick based)
• Dedicated Keybinds screen for rebinding UI-Utils actions
• Legacy direct key fields still present: restore GUI and delay toggle
• Disconnect method selector (used by UI‑Utils “Disconnect” buttons)
  • Includes QUIT, packet-based kick styles and lag styles
  • Includes TIMEOUT mode (KeepAlive wait + block + delayed action)

Packet HUD

• In-game HUD rendering of packet flow.
• Format:
  • 888 IN / 999 OUT
  • 20 QUEUED (only shown when queue > 0)
• HUD color is configurable in Settings
• Positionable to all four corners

Themed UI‑Utils buttons

• Colored button renderer is used across UI‑Utils screens and injected buttons
• Removes mixed vanilla/colored button look

Log Example

[12:52:54]: Fabricate ClickSlot: syncId=6, revision=1, slot=2, button=0, action=PICKUP, times=1, diffSlots=1, carriedBefore=<empty>, carriedAfter=class_10939[item=Reference{ResourceKey[minecraft:item / minecraft:oak_slab]=minecraft:oak_slab}, count=11, components=class_10936[addedComponents={}, removedComponents=[]]]
[12:52:54]: Fabricate ClickSlot: menu.containerId=6, syncIdMatch=true, diffDetail=[2: minecraft:oak_slabx11 -> empty] 
[12:52:54]: UiUtilsConnectionMixin: attempting to send UI packet class_2813 (sendUiPackets=true, delayUiPackets=false)

UI‑Utils Commands

Supported roots:

• .uiutils
• uiutils

Main commands:

• help
• enable / disable
• close
• desync
• apt (aliases: advancedpacketscanner, advancedpackettool)
• chat <message>
• screen <save|load|list|info> [slot]
• plugins
• commands
• queue <list|clear|sendone|poplast|spam [times]>
• packethud <on|off|toggle>
• delay <on|off|toggle>
• closedelay <ticks>
• commanddelay <ticks> (alias: cmddelay)
• sendpackets <on|off|toggle>
• disconnectmethod <list|current|METHOD>
• timeout <seconds>
• lagmethod <list|current|METHOD>
• settings
• autoduper <open|start|stop|status|slot|command|attempt|hybrid [openCommand]>
• gui <status|save|saveclose|load|clear|copy|steal|dump|tools>
• guilog <on|off|toggle|file|clear|copy|open>
• guipackets <list|cycle <id>|reset|delay <ticks>|screen>

Macro Import/Export

Open Macros from the overlay to use the Macro Library.

Workflow:

1. Create or edit a macro, then save it.
2. To export, select the macro and choose an export folder (... opens folder picker).
3. To import, choose a .nbt file (... opens file picker) and import it.

Path behavior:

• Import field points to: <gameDir>/config/ui-utils/macro_import
• Export field points to: <gameDir>/config/ui-utils/macro_export
• Both folders are created automatically if they do not exist.

Notes on the Mojmap Migration

• Entire codebase uses Mojang mappings for clarity and forward‑compat.
• The default jar is compiled against 26.1 and includes runtime shims for API differences through 26.3. Minecraft 26.4 and later are not declared supported.
• Packet types are discovered at runtime with a reflective catalog for resilience across dot‑releases.
• APT is fully in-game: a custom dual-list widget backs the packet pickers, and the packet dumping engine is ported from Wurst7-CevAPI.

Credits

• Original concept: UI‑Utils (MrBreakNFix and contributors)
• Modernization + new features: CevAPI
• Advanced Packet Tool inspired by HelixCraft's Packet Logger
• Extra UI-Utils options inspired by FrannnnDev's fork
• Published with approval from MrBreakNFix
• DupeDB for their dupe list. Will eventually add API access for live updates.

License

This project is licensed under the GNU General Public License v3.0 or later (GPL-3.0-or-later). See LICENSE.

Disclaimer

UI‑Utils is a debugging and testing toolkit. Be nice, follow server rules and local laws. You are responsible for how you use these tools.