Vertical Slabs

Evidence

Ran on Kiln's test stand (2026-11-04): VerticalSlabs did not start: java.lang.NoClassDefFoundError: net/minecraft/references/BlockItemId; VerticalSlabsClient did not start: java.lang.NoClassDefFoundError: net/minecraft/client/data/models/model/ModelTemplate.

What it needs from Kiln

• Mixin
• net.fabricmc.fabric.api.advancement.v1.AdvancementEvents
• net.fabricmc.fabric.api.advancement.v1.AdvancementEvents.Modify
• net.fabricmc.fabric.api.creativetab.v1.FabricCreativeModeTab
• net.fabricmc.fabric.api.registry.FlammableBlockRegistry
• net.fabricmc.fabric.api.registry.OxidizableBlocksRegistry
• net.minecraft.advancements.Advancement
• net.minecraft.advancements.Advancement.Builder
• net.minecraft.advancements.AdvancementRequirements
• net.minecraft.advancements.AdvancementRequirements.Strategy
• net.minecraft.advancements.predicates.BlockPredicate
• net.minecraft.advancements.predicates.BlockPredicate.Builder
• net.minecraft.advancements.predicates.ItemPredicate
• net.minecraft.advancements.predicates.ItemPredicate.Builder
• net.minecraft.advancements.predicates.LocationPredicate
• net.minecraft.advancements.predicates.LocationPredicate.Builder
• net.minecraft.advancements.triggers.Criterion
• net.minecraft.advancements.triggers.ItemUsedOnLocationTrigger
• net.minecraft.advancements.triggers.ItemUsedOnLocationTrigger.TriggerInstance
• net.minecraft.client.data.models.BlockModelGenerators
• net.minecraft.client.data.models.MultiVariant
• net.minecraft.client.data.models.model.ModelTemplate
• net.minecraft.client.data.models.model.ModelTemplates
• net.minecraft.client.data.models.model.TextureMapping
• net.minecraft.client.data.models.model.TextureSlot
• net.minecraft.core.Direction.Axis
• net.minecraft.data.advancements.packs.VanillaHusbandryAdvancements
• net.minecraft.references.BlockItemId
• net.minecraft.tags.BlockItemTagId
• net.minecraft.tags.FluidTags
• net.minecraft.world.item.CreativeModeTab.Builder
• net.minecraft.world.item.CreativeModeTab.DisplayItemsGenerator
• net.minecraft.world.item.CreativeModeTab.ItemDisplayParameters
• net.minecraft.world.item.CreativeModeTab.Output
• net.minecraft.world.item.DyeColor
• net.minecraft.world.item.HoneycombItem
• net.minecraft.world.level.block.ColorCollection
• net.minecraft.world.level.block.Mirror
• net.minecraft.world.level.block.Rotation
• net.minecraft.world.level.block.SimpleWaterloggedBlock
• net.minecraft.world.level.block.WeatheringCopper
• and 68 more

On the roadmap: Minecraft's libraries and client API (0.2), Code next to data (0.3), Mixin (0.5)

In the author's words

Yet another vertical slab mod.

Scan

Scanned on 4 November 2026 against Kiln 0.2.0, file vertical_slabs-1.0.4+mc26.3.jar. The scan reads the mod's classes; it does not run them.