ModsFinder

x4UI

by X4yi

x4UI is a Forge library for building user interfaces, with panels, layouts, event handling and a text width cache for Minecraft 1.12.2.

ForgeClient-side onlyGNU General Public License v3.0 onlyOpen source1.12.2

What it does

Developers who build screens in Forge 1.12.2 can use x4UI to create nested panels, buttons, toggles and sliders, which the framework handles automatically. Required by 1 other catalog mod, LethalWeaponry, which depends on it to run.

The framework is client-side only, so the mod is needed on the player's side and servers can run without it. It is published for Forge and for 1.12.2 alone, with the latest Forge file r1.0b5 dated 2026-09-11 on the beta channel. The first build appeared on 2026-08-02. x4UI is open source under the GNU General Public License v3.0 only, and the source code and a wiki are linked publicly by the author X4yi.

Key features

  1. FlexBox layouts

    Panels stack vertically or horizontally with gaps and margins, and manual math placement is still available when needed.

  2. Event bubbling

    Clicks and scroll events respect Z-index, and the top-most overlapping button receives the click and stops propagation.

  3. Smooth transitions

    Built-in interpolation animates hover and click transitions, with timing scaled by delta time so speed stays the same on any hardware.

  4. Memory-safe text caching

    A font width cache handles complex text such as Markdown, and cached strings are limited by an LRU eviction policy.

Compatibility

Latest build for each game version and loader.

No stable releases
Every published file is a beta or alpha build.
1.12.2r1.0b5
ReleaseBetaAlphaNot available

Only full game releases are shown. This mod publishes no snapshot builds.

Required by 1 mod

LethalWeaponry1.12.2

Questions

Does LethalWeaponry need x4UI?

Yes. LethalWeaponry is the one catalog mod listed as requiring x4UI, so x4UI must be installed alongside it.

Does x4UI have to be installed on servers?

No. Players add it to their own game, and a server needs no copy.

Which Minecraft version does x4UI support?

The mod targets Minecraft 1.12.2 on Forge only. The latest file is r1.0b5 for 1.12.2, released on the beta channel.

In the catalog

x4UI is one of 3,514 Library mods on ModsFinder, and one of 1,576 Library mods for Forge. 2,920 mods support Minecraft 1.12.2.

Library mods3,514Forge modsMods for 1.12.22,920

More from X4yi

All projects
LethalWeaponry1.12.2

Similar mods

Just Enough Items (JEI)1.8 – 26.3Geckolib1.12.2 – 26.3Konkrete1.12 – 26.3CreativeCore1.12.2 – 26.3Bookshelf1.7.10 – 26.3MaLiLib1.12 – 26.3

What the author says

A modern, high-performance, object-oriented GUI framework for Minecraft Forge 1.12.2. X4UI is a standalone, flexible, and dynamic user interface framework extracted from Hammers Unbound. It brings modern web-like development paradigms (like FlexBox layouts, DOM-tree structures, and event bubbling) straight into Forge…
X4yi, on the Modrinth page

Official listing

Owner
X4yi
Published
2026-08-02
Updated on Modrinth
2026-09-11
Facts verified
2026-10-15

Tags

Library
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