Butterfly API

Butterfly API bundles helper systems that cover common content work: registration of items, blocks, sounds, entities, particles, enchantments, recipes and status effects, along with creative tabs and basic gameplay and math utilities. Developers who would otherwise write a lot of boilerplate for these tasks can call the library instead, which leaves their own code more compact.

Beyond registration, the library includes a text system with control over colors, gradients, rotations and mirroring, a tooltip system for expanding item tooltips, and an outline system that extends the vanilla glowing effect so it can be applied to nearly anything. A shared plush system adds small placeable plush blocks with options such as facing direction and waterlogging, plus optional honk sounds and squish behavior that use GeckoLib animations.

Butterfly API is open source under the MIT License and runs on client and server, so the library must be present on both sides for mods that depend on it. It is published for Fabric only, with builds covering 1.20.1 – 26.3. Its GitHub page holds setup notes and usage examples for developers who want to build on the same helpers.