Ctrl+Z

Evidence

Ran on Kiln's test stand (2026-11-04): CtrlZ did not start: java.lang.NoClassDefFoundError: net/fabricmc/fabric/api/networking/v1/PayloadTypeRegistry; CtrlZClient did not start: java.lang.NoClassDefFoundError: net/minecraft/network/protocol/common/custom/CustomPacketPayload.

What it needs from Kiln

• Mixin
• com.mojang.blaze3d.platform.InputConstants.Key
• net.fabricmc.fabric.api.client.networking.v1.ClientPlayNetworking
• net.fabricmc.fabric.api.networking.v1.PayloadTypeRegistry
• net.fabricmc.fabric.api.networking.v1.ServerPlayNetworking
• net.fabricmc.fabric.api.networking.v1.ServerPlayNetworking.Context
• net.fabricmc.fabric.api.networking.v1.ServerPlayNetworking.PlayPayloadHandler
• net.minecraft.client.gui.components.AbstractWidget
• net.minecraft.client.gui.components.Button
• net.minecraft.client.gui.components.Button.OnPress
• net.minecraft.client.input.KeyEvent
• net.minecraft.client.input.MouseButtonEvent
• net.minecraft.nbt.CompoundTag
• net.minecraft.network.codec.ByteBufCodecs
• 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.server.MinecraftServer
• net.minecraft.server.network.ServerGamePacketListenerImpl
• net.minecraft.server.players.PlayerList
• net.minecraft.util.Prediction
• net.minecraft.util.ProblemReporter
• net.minecraft.util.ProblemReporter.PathElement
• net.minecraft.util.ProblemReporter.ScopedCollector
• net.minecraft.world.damagesource.DamageSources
• net.minecraft.world.entity.Entity.RemovalReason
• net.minecraft.world.entity.EntityProcessor
• net.minecraft.world.entity.EntitySpawnReason
• net.minecraft.world.entity.EntitySpawnRequest
• net.minecraft.world.entity.EntityType
• net.minecraft.world.entity.item.ItemEntity
• net.minecraft.world.entity.item.PrimedTnt
• net.minecraft.world.entity.player.Inventory
• net.minecraft.world.level.block.entity.BlockEntity
• net.minecraft.world.level.storage.TagValueInput
• net.minecraft.world.level.storage.TagValueOutput
• InputConstants.isKeyDown()
• InputConstants.Type.getOrCreate()
• KeyMapping.matches()
• GuiGraphicsExtractor.disableScissor()
• and 35 more

On the roadmap: Minecraft's libraries and client API (0.2), Code next to data (0.3), Machines (0.4), Mixin (0.5)

In the author's words

Undo & Redo things, useful for redstone or building

Scan

Scanned on 4 November 2026 against Kiln 0.2.0, file ctrl-z-1.0.6.jar. The scan reads the mod's classes; it does not run them.