Mekanism

MBD2 21.1.1

Mekanism adds unified chemical storage/recipe content and heat storage/transfer. MBD2 1.21.1 does not use the old separate gas, infusion, pigment, and slurry capability families.

The `chemical_tank` editor fields; `mek_heat_container` is visible directly below it in the Trait list.

What is added

Layer	Registry name	Purpose
Recipe capability	mek_chemical	Transfer a unified ChemicalStackIngredient
Recipe capability	mek_heat	Transfer heat as a double
Trait	chemical_tank	Persist chemicals and expose Mekanism's chemical block capability
Trait	mek_heat_container	Persist heat/temperature and expose Mekanism's heat capability
Condition	mekanism_heat	Check a min/max temperature without transferring heat
UI element	chemical-slot	Bind a chemical tank to authored machine UI

All entries are conditional on mod ID mekanism.

Chemical machine setup

Add chemical_tank in the Trait editor. Configure tank count, per-tank long capacity, duplicate-chemical policy, chemical/tag whitelist or blacklist, recipe/GUI/capability IO, auto IO, and optional tank rendering. Name multiple tanks and use recipe slotName when one is dedicated to input or output.

The Trait exposes mekanism.common.capabilities.Capabilities.CHEMICAL.block(). Container interaction in UI uses chemical-slot; external pipes still obey capability-side and IO settings.

In KubeJS, each string is parsed by MBD2's chemical ingredient parser:

ServerEvents.recipes(event => {
  event.recipes.example.chemical_reactor()
    .id('example:chemical_reaction')
    .duration(80)
    .inputChemicals('100x mekanism:hydrogen', '50x mekanism:oxygen')
    .outputChemicals('100x mekanism:water_vapor')
})

Use current Mekanism chemical IDs and validate script parsing in the shipped build. Historical inputGas, inputSlurry, inputPigment, and inputInfusion examples are obsolete.

Heat and temperature

Add mek_heat_container and configure capacity, inverse insulation/conduction values, recipe/capability IO, and auto IO. inputHeat removes heat; outputHeat inserts heat. Put the content inside perTick(...) for continuous transfer.

ServerEvents.recipes(event => {
  event.recipes.example.heated_reactor()
    .id('example:hot_reaction')
    .duration(200)
    .perTick(r => r.inputHeat(2.5))
    .mekTemperatureCondition(600, 1200)
    .inputItems('minecraft:raw_iron')
    .outputItems('minecraft:iron_ingot')
})

Temperatures are compared with the heat handler's value (Kelvin in Mekanism semantics). mekTemperatureCondition only gates the recipe; it does not reserve or consume heat. Add inputHeat separately when processing must cost heat.

Failure checklist

• Capability missing in editor: Mekanism was absent during registry discovery or versions are incompatible.
• Recipe never matches: machine lacks the corresponding Trait, handler recipe IO is wrong, or slotName targets another tank.
• Pipes cannot connect: check capability IO and side mapping; recipe IO alone does not expose the block capability.
• Temperature passes but no heat is consumed: expected for a condition-only recipe.
• Viewer shows a blank chemical: verify the chemical ID and the installed viewer integration.