Capabilities, Handlers, and Conditions

MBD2 21.1.1

An MBD2 recipe is not a direct inventory operation. It contains typed Content; recipe logic routes each content list to compatible IRecipeHandler instances supplied by machine traits, then evaluates conditions against the machine and world.

Three concepts that must match

Concept	Owns	Example
RecipeCapability<T>	Content type, codec, editor/XEI display, KubeJS conversion	forge_energy owns integer FE content
Trait/handler	Machine storage and actual input/output operation	Forge energy trait exposes ForgeEnergyRecipeHandler
RecipeCondition	A non-consuming predicate	Redstone signal is between 7 and 15

A registered capability without a handler can be authored but never completes. A trait whose recipe IO is IN cannot satisfy output content. A condition never substitutes for missing input.

Continue to the capability reference, condition reference, or Java extension engine.