fabric-121-api-pitfalls

What problem does it solve?

This Skill helps Minecraft mod developers avoid the most common Fabric 1.21 Yarn mapping and API pitfalls that cause compile errors, broken screen handlers, and incorrect data persistence.

Core Features & Use Cases

• NBT persistence: Handles the updated read and write NBT signatures that require registry lookup context.
• GUI and inventory fixes: Covers furnace fuel and output slots, property delegates, screen handler factories, and client-side sound behavior.
• Registry and gameplay API changes: Explains 1.21 changes for fuels, brewing recipes, potions, enchantments, jukebox discs, and entity damage detection.
• Use case: A mod developer can use this Skill to quickly resolve a failing Fabric 1.21 feature, such as a custom block entity, a brewing GUI, or a disc-playing block.

Quick Start

Use this Skill when you are fixing a Fabric 1.21 mod and need the correct Yarn-safe patterns for NBT, screen handlers, registries, potions, enchantments, or jukebox audio.