JelloUI is an independent client-side UI platform and prerequisite mod for Minecraft Fabric 26.2.
It provides a reusable, versioned public API for polished Jello-style interfaces: screens, ClickGUI content, HUDs, notifications, themes, TrueType typography, animation and easing, profiles, keybinds, world-space rendering helpers, and Music Player / Music Manager.
JelloUI itself contains no gameplay modules. Install it when another mod depends on its API, or when you want the core Jello interface without gameplay features.
The separate JelloUI Official Addon(Coming soon) restores the first-party Jello GUI modules. Third-party mods can also register their own screens, modules, HUDs and world markers through the public API.
What you get
- Polished Jello-style screens and widgets
- Automatic ClickGUI bridges for registered modules and settings
- HUD, notification, profile and keybind infrastructure
- TrueType font rendering, themes, blur, stencil, scissor and antialiased rounded geometry
- Reusable world-space rendering helpers
- Music Player and Music Manager
- Versioned public API with ownership tracking and exception isolation

Music playback setup
Music playback requires yt-dlp. JelloUI does not download it automatically.
Install it using one of these methods:
- Windows: download
yt-dlp.exefrom the official releases page, then place it injello-ui/music/inside your Minecraft instance directory. - Windows with WinGet: run
winget install yt-dlp.yt-dlp. - macOS: run
brew install yt-dlp. - Linux: install the
yt-dlppackage through your distribution's package manager.
Alternatively, install yt-dlp on your system PATH.
If YouTube blocks playback with a bot-verification message, place an exported Netscape-format cookies.txt file in jello-ui/music/. JelloUI will pass it to yt-dlp for playback authentication.

ViaFabricPlus 4.6.0 or newer is recommended.
For developers
The public API is documented at public API docs. Addons implement JelloAddonInitializer and declare the jelloui:addon Fabric entrypoint.

