Marlow's Crystal Optimizer

Evidence

Ran on Kiln's test stand (2026-11-04): MarlowCrystalFabric did not start: java.lang.NoClassDefFoundError: net/minecraft/world/entity/boss/enderdragon/EndCrystal.

What it needs from Kiln

• Mixin
• net.fabricmc.fabric.api.client.networking.v1.ClientConfigurationConnectionEvents
• net.fabricmc.fabric.api.client.networking.v1.ClientConfigurationConnectionEvents.Disconnect
• net.fabricmc.fabric.api.client.networking.v1.ClientPlayConnectionEvents
• net.fabricmc.fabric.api.client.networking.v1.ClientPlayConnectionEvents.Disconnect
• net.fabricmc.fabric.api.client.networking.v1.ClientPlayConnectionEvents.Join
• net.fabricmc.fabric.api.client.networking.v1.ClientPlayNetworking
• net.fabricmc.fabric.api.client.networking.v1.ClientPlayNetworking.Context
• net.fabricmc.fabric.api.client.networking.v1.ClientPlayNetworking.PlayPayloadHandler
• net.fabricmc.fabric.api.networking.v1.PacketSender
• net.fabricmc.fabric.api.networking.v1.PayloadTypeRegistry
• net.fabricmc.loader.api.ModContainer
• net.fabricmc.loader.api.Version
• net.fabricmc.loader.api.metadata.ModMetadata
• net.minecraft.network.FriendlyByteBuf
• net.minecraft.network.chat.HoverEvent
• net.minecraft.network.chat.HoverEvent.ShowText
• net.minecraft.network.chat.Style
• net.minecraft.network.codec.StreamCodec
• net.minecraft.network.protocol.common.custom.CustomPacketPayload
• net.minecraft.network.protocol.common.custom.CustomPacketPayload.Type
• net.minecraft.network.protocol.common.custom.CustomPacketPayload.TypeAndCodec
• net.minecraft.world.effect.MobEffectInstance
• net.minecraft.world.effect.MobEffects
• net.minecraft.world.entity.EquipmentSlot
• net.minecraft.world.entity.ai.attributes.AttributeModifier
• net.minecraft.world.entity.boss.enderdragon.EndCrystal
• net.minecraft.world.level.border.WorldBorder
• net.minecraft.world.phys.EntityHitResult
• net.minecraft.world.phys.HitResult.Type
• FabricLoader.getModContainer()
• Minecraft.execute()
• Minecraft.getCameraEntity()
• Minecraft.hitResult
• Minecraft.isLocalServer()
• ClientLevel.getWorldBorder()
• ClientLevel.isEmptyBlock()
• LocalPlayer.getEffect()
• LocalPlayer.raycastHitResult()
• Component.copy()
• MutableComponent.withStyle()
• and 7 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

Optimization that fixes waiting on the server after crystal break before end crystal entities are cleaned.

Scan

Scanned on 4 November 2026 against Kiln 0.2.0, file marlows-crystal-optimizer-2.0.0+mc26.1-26.3.jar. The scan reads the mod's classes; it does not run them.