1.21 groundwork

2024-06-18 17:18:04 +01:00
parent 303f5eedac
commit ad44891f5f
23 changed files with 1191 additions and 0 deletions
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -32,6 +32,7 @@ dependencies {
    implementation(project(path = ":eco-core:core-nms:v1_20_R2", configuration = "reobf"))
    implementation(project(path = ":eco-core:core-nms:v1_20_R3", configuration = "reobf"))
    implementation(project(path = ":eco-core:core-nms:v1_20_6", configuration = "reobf"))
+    implementation(project(path = ":eco-core:core-nms:v1_21", configuration = "reobf"))
 }

 allprojects {
@@ -162,6 +163,10 @@ allprojects {
            sourceCompatibility = JavaVersion.VERSION_17
            targetCompatibility = JavaVersion.VERSION_17
            withSourcesJar()
+
+            toolchain {
+                languageVersion = JavaLanguageVersion.of(17)
+            }
        }

        test {
--- a/eco-core/core-nms/nms-common/build.gradle.kts
+++ b/eco-core/core-nms/nms-common/build.gradle.kts
@@ -8,3 +8,9 @@ version = rootProject.version
 dependencies {
    paperweight.paperDevBundle("1.17.1-R0.1-SNAPSHOT")
 }
+
+java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(17)
+    }
+}
--- a/eco-core/core-nms/v1_17_R1/build.gradle.kts
+++ b/eco-core/core-nms/v1_17_R1/build.gradle.kts
@@ -8,6 +8,7 @@ version = rootProject.version
 dependencies {
    implementation(project(":eco-core:core-nms:nms-common"))
    paperweight.paperDevBundle("1.17.1-R0.1-SNAPSHOT")
+    pluginRemapper("net.fabricmc:tiny-remapper:0.10.3:fat")

    implementation("net.kyori:adventure-text-minimessage:4.2.0-SNAPSHOT") {
        version {
@@ -37,3 +38,9 @@ tasks {
        )
    }
 }
+
+java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(17)
+    }
+}
--- a/eco-core/core-nms/v1_18_R1/build.gradle.kts
+++ b/eco-core/core-nms/v1_18_R1/build.gradle.kts
@@ -37,3 +37,9 @@ tasks {
        )
    }
 }
+
+java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(17)
+    }
+}
--- a/eco-core/core-nms/v1_18_R2/build.gradle.kts
+++ b/eco-core/core-nms/v1_18_R2/build.gradle.kts
@@ -37,3 +37,9 @@ tasks {
        )
    }
 }
+
+java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(17)
+    }
+}
--- a/eco-core/core-nms/v1_19_R1/build.gradle.kts
+++ b/eco-core/core-nms/v1_19_R1/build.gradle.kts
@@ -37,3 +37,9 @@ tasks {
        )
    }
 }
+
+java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(17)
+    }
+}
--- a/eco-core/core-nms/v1_21/build.gradle.kts
+++ b/eco-core/core-nms/v1_21/build.gradle.kts
@@ -0,0 +1,51 @@
+plugins {
+    id("io.papermc.paperweight.userdev")
+}
+
+group = "com.willfp"
+version = rootProject.version
+
+dependencies {
+    implementation(project(":eco-core:core-nms:nms-common"))
+    paperweight.paperDevBundle("1.21-R0.1-SNAPSHOT")
+
+    implementation("net.kyori:adventure-text-minimessage:4.11.0") {
+        version {
+            strictly("4.11.0")
+        }
+        exclude(group = "net.kyori", module = "adventure-api")
+    }
+}
+
+tasks {
+    build {
+        dependsOn(reobfJar)
+    }
+
+    reobfJar {
+        mustRunAfter(shadowJar)
+    }
+
+    shadowJar {
+        relocate(
+            "com.willfp.eco.internal.spigot.proxy.common",
+            "com.willfp.eco.internal.spigot.proxy.v1_21.common"
+        )
+        relocate(
+            "net.kyori.adventure.text.minimessage",
+            "com.willfp.eco.internal.spigot.proxy.v1_21.minimessage"
+        )
+    }
+
+    java {
+        sourceCompatibility = JavaVersion.VERSION_21
+        targetCompatibility = JavaVersion.VERSION_21
+        withSourcesJar()
+    }
+
+    compileKotlin {
+        kotlinOptions {
+            jvmTarget = "21"
+        }
+    }
+}
--- a/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/BukkitCommands.kt
+++ b/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/BukkitCommands.kt
@@ -0,0 +1,35 @@
+package com.willfp.eco.internal.spigot.proxy.v1_21
+
+import com.willfp.eco.core.command.PluginCommandBase
+import com.willfp.eco.internal.spigot.proxy.BukkitCommandsProxy
+import org.bukkit.Bukkit
+import org.bukkit.command.Command
+import org.bukkit.command.SimpleCommandMap
+import org.bukkit.craftbukkit.CraftServer
+import java.lang.reflect.Field
+
+class BukkitCommands : BukkitCommandsProxy {
+    private val knownCommandsField: Field by lazy {
+        SimpleCommandMap::class.java.getDeclaredField("knownCommands")
+            .apply {
+                isAccessible = true
+            }
+    }
+
+    @Suppress("UNCHECKED_CAST")
+    private val knownCommands: MutableMap<String, Command>
+        get() = knownCommandsField.get(getCommandMap()) as MutableMap<String, Command>
+
+    override fun getCommandMap(): SimpleCommandMap {
+        return (Bukkit.getServer() as CraftServer).commandMap
+    }
+
+    override fun syncCommands() {
+        (Bukkit.getServer() as CraftServer).syncCommands()
+    }
+
+    override fun unregisterCommand(command: PluginCommandBase) {
+        knownCommands.remove(command.name)
+        knownCommands.remove("${command.plugin.name.lowercase()}:${command.name}")
+    }
+}
--- a/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/CommonsInitializer.kt
+++ b/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/CommonsInitializer.kt
@@ -0,0 +1,171 @@
+package com.willfp.eco.internal.spigot.proxy.v1_21
+
+import com.willfp.eco.core.EcoPlugin
+import com.willfp.eco.internal.spigot.proxy.CommonsInitializerProxy
+import com.willfp.eco.internal.spigot.proxy.common.CommonsProvider
+import com.willfp.eco.internal.spigot.proxy.common.packet.PacketInjectorListener
+import com.willfp.eco.internal.spigot.proxy.common.toResourceLocation
+import net.kyori.adventure.text.Component
+import net.kyori.adventure.text.serializer.json.JSONComponentSerializer
+import net.minecraft.core.component.DataComponents
+import net.minecraft.core.registries.BuiltInRegistries
+import net.minecraft.nbt.CompoundTag
+import net.minecraft.nbt.Tag
+import net.minecraft.resources.ResourceLocation
+import net.minecraft.server.level.ServerPlayer
+import net.minecraft.world.entity.PathfinderMob
+import net.minecraft.world.item.Item
+import org.bukkit.Bukkit
+import org.bukkit.Material
+import org.bukkit.NamespacedKey
+import org.bukkit.craftbukkit.CraftServer
+import org.bukkit.craftbukkit.entity.CraftEntity
+import org.bukkit.craftbukkit.entity.CraftMob
+import org.bukkit.craftbukkit.entity.CraftPlayer
+import org.bukkit.craftbukkit.inventory.CraftItemStack
+import org.bukkit.craftbukkit.inventory.CraftMetaArmor
+import org.bukkit.craftbukkit.persistence.CraftPersistentDataContainer
+import org.bukkit.craftbukkit.persistence.CraftPersistentDataTypeRegistry
+import org.bukkit.craftbukkit.util.CraftMagicNumbers
+import org.bukkit.craftbukkit.util.CraftNamespacedKey
+import org.bukkit.entity.LivingEntity
+import org.bukkit.entity.Mob
+import org.bukkit.entity.Player
+import org.bukkit.inventory.ItemStack
+import org.bukkit.persistence.PersistentDataContainer
+import java.lang.reflect.Field
+
+class CommonsInitializer : CommonsInitializerProxy {
+    override fun init(plugin: EcoPlugin) {
+        CommonsProvider.setIfNeeded(CommonsProviderImpl)
+        plugin.onEnable {
+            plugin.eventManager.registerListener(PacketInjectorListener)
+        }
+    }
+
+    object CommonsProviderImpl : CommonsProvider {
+        private val cisHandle: Field = CraftItemStack::class.java.getDeclaredField("handle").apply {
+            isAccessible = true
+        }
+
+        private val pdcRegsitry = CraftMetaArmor::class.java
+            .superclass // Access CraftMetaItem
+            .getDeclaredField("DATA_TYPE_REGISTRY")
+            .apply { isAccessible = true }
+            .get(null) as CraftPersistentDataTypeRegistry
+
+        override val nbtTagString = CraftMagicNumbers.NBT.TAG_STRING
+
+        override fun toPathfinderMob(mob: Mob): PathfinderMob? {
+            val craft = mob as? CraftMob ?: return null
+            return craft.handle as? PathfinderMob
+        }
+
+        override fun toResourceLocation(namespacedKey: NamespacedKey): ResourceLocation =
+            CraftNamespacedKey.toMinecraft(namespacedKey)
+
+        override fun asNMSStack(itemStack: ItemStack): net.minecraft.world.item.ItemStack {
+            return if (itemStack !is CraftItemStack) {
+                CraftItemStack.asNMSCopy(itemStack)
+            } else {
+                cisHandle[itemStack] as net.minecraft.world.item.ItemStack? ?: CraftItemStack.asNMSCopy(itemStack)
+            }
+        }
+
+        override fun asBukkitStack(itemStack: net.minecraft.world.item.ItemStack): ItemStack {
+            return CraftItemStack.asCraftMirror(itemStack)
+        }
+
+        override fun mergeIfNeeded(itemStack: ItemStack, nmsStack: net.minecraft.world.item.ItemStack) {
+            if (itemStack !is CraftItemStack) {
+                itemStack.itemMeta = CraftItemStack.asCraftMirror(nmsStack).itemMeta
+            }
+        }
+
+        override fun toBukkitEntity(entity: net.minecraft.world.entity.LivingEntity): LivingEntity? =
+            CraftEntity.getEntity(Bukkit.getServer() as CraftServer, entity) as? LivingEntity
+
+        override fun makePdc(tag: CompoundTag, base: Boolean): PersistentDataContainer {
+            fun emptyPdc(): CraftPersistentDataContainer = CraftPersistentDataContainer(pdcRegsitry)
+
+            fun CompoundTag?.toPdc(): PersistentDataContainer {
+                val pdc = emptyPdc()
+                this ?: return pdc
+                val keys = this.allKeys
+                for (key in keys) {
+                    pdc.put(key, this[key])
+                }
+
+                return pdc
+            }
+
+            return if (base) {
+                tag.toPdc()
+            } else {
+                if (tag.contains("PublicBukkitValues")) {
+                    tag.getCompound("PublicBukkitValues").toPdc()
+                } else {
+                    emptyPdc()
+                }
+            }
+        }
+
+        override fun setPdc(
+            tag: CompoundTag,
+            pdc: PersistentDataContainer?,
+            item: net.minecraft.world.item.ItemStack?
+        ) {
+            fun CraftPersistentDataContainer.toTag(): CompoundTag {
+                val compound = CompoundTag()
+                val rawPublicMap: Map<String, Tag> = this.raw
+                for ((key, value) in rawPublicMap) {
+                    compound.put(key, value)
+                }
+
+                return compound
+            }
+
+            val container = when (pdc) {
+                is CraftPersistentDataContainer? -> pdc
+                else -> null
+            }
+
+            if (item != null) {
+                if (container != null && !container.isEmpty) {
+                    for (key in tag.allKeys.toSet()) {
+                        tag.remove(key)
+                    }
+
+                    tag.merge(container.toTag())
+                } else {
+                    item.remove(DataComponents.CUSTOM_DATA)
+                }
+            } else {
+                if (container != null && !container.isEmpty) {
+                    tag.put("PublicBukkitValues", container.toTag())
+                } else {
+                    tag.remove("PublicBukkitValues")
+                }
+            }
+        }
+
+        override fun materialToItem(material: Material): Item =
+            BuiltInRegistries.ITEM.getOptional(material.key.toResourceLocation())
+                .orElseThrow { IllegalArgumentException("Material is not item!") }
+
+        override fun itemToMaterial(item: Item) =
+            Material.getMaterial(BuiltInRegistries.ITEM.getKey(item).path.uppercase())
+                ?: throw IllegalArgumentException("Invalid material!")
+
+        override fun toNMS(player: Player): ServerPlayer {
+            return (player as CraftPlayer).handle
+        }
+
+        override fun toNMS(component: Component): net.minecraft.network.chat.Component {
+            val json = JSONComponentSerializer.json().serialize(component)
+            val holderLookupProvider = (Bukkit.getServer() as CraftServer).server.registryAccess()
+
+            return net.minecraft.network.chat.Component.Serializer.fromJson(json, holderLookupProvider)!!
+        }
+    }
+}
--- a/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/DisplayName.kt
+++ b/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/DisplayName.kt
@@ -0,0 +1,59 @@
+package com.willfp.eco.internal.spigot.proxy.v1_21
+
+import com.willfp.eco.core.packet.Packet
+import com.willfp.eco.core.packet.sendPacket
+import com.willfp.eco.internal.spigot.proxy.DisplayNameProxy
+import com.willfp.eco.internal.spigot.proxy.common.toNMS
+import net.kyori.adventure.text.Component
+import net.minecraft.network.protocol.game.ClientboundSetEntityDataPacket
+import net.minecraft.network.syncher.EntityDataAccessor
+import net.minecraft.network.syncher.SynchedEntityData
+import net.minecraft.world.entity.Entity
+import org.bukkit.craftbukkit.entity.CraftLivingEntity
+import org.bukkit.entity.LivingEntity
+import org.bukkit.entity.Player
+import java.util.Optional
+
+@Suppress("UNCHECKED_CAST")
+class DisplayName : DisplayNameProxy {
+    private val displayNameAccessor = Entity::class.java
+        .declaredFields
+        .filter { it.type == EntityDataAccessor::class.java }
+        .toList()[2]
+        .apply { isAccessible = true }
+        .get(null) as EntityDataAccessor<Optional<net.minecraft.network.chat.Component>>
+
+    private val customNameVisibleAccessor = Entity::class.java
+        .declaredFields
+        .filter { it.type == EntityDataAccessor::class.java }
+        .toList()[3]
+        .apply { isAccessible = true }
+        .get(null) as EntityDataAccessor<Boolean>
+
+    override fun setClientsideDisplayName(
+        entity: LivingEntity,
+        player: Player,
+        displayName: Component,
+        visible: Boolean
+    ) {
+        if (entity !is CraftLivingEntity) {
+            return
+        }
+
+        val nmsComponent = displayName.toNMS()
+
+        val nmsEntity = entity.handle
+        nmsEntity.isCustomNameVisible
+        val entityData = SynchedEntityData.Builder(nmsEntity).build()
+
+        entityData.set(displayNameAccessor, Optional.of(nmsComponent), true)
+        entityData.set(customNameVisibleAccessor, visible, true)
+
+        val packet = ClientboundSetEntityDataPacket(
+            nmsEntity.id,
+            entityData.packDirty() ?: throw IllegalStateException("No packed entity data")
+        )
+
+        player.sendPacket(Packet(packet))
+    }
+}
--- a/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/DummyEntityFactory.kt
+++ b/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/DummyEntityFactory.kt
@@ -0,0 +1,15 @@
+package com.willfp.eco.internal.spigot.proxy.v1_21
+
+import com.willfp.eco.internal.entities.EcoDummyEntity
+import com.willfp.eco.internal.spigot.proxy.DummyEntityFactoryProxy
+import org.bukkit.Location
+import org.bukkit.craftbukkit.CraftWorld
+import org.bukkit.entity.Entity
+import org.bukkit.entity.Zombie
+
+class DummyEntityFactory : DummyEntityFactoryProxy {
+    override fun createDummyEntity(location: Location): Entity {
+        val world = location.world as CraftWorld
+        return EcoDummyEntity(world.createEntity(location, Zombie::class.java))
+    }
+}
--- a/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/EntityControllerFactory.kt
+++ b/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/EntityControllerFactory.kt
@@ -0,0 +1,12 @@
+package com.willfp.eco.internal.spigot.proxy.v1_21
+
+import com.willfp.eco.core.entities.ai.EntityController
+import com.willfp.eco.internal.spigot.proxy.EntityControllerFactoryProxy
+import com.willfp.eco.internal.spigot.proxy.v1_21.entity.EcoEntityController
+import org.bukkit.entity.Mob
+
+class EntityControllerFactory : EntityControllerFactoryProxy {
+    override fun <T : Mob> createEntityController(entity: T): EntityController<T> {
+        return EcoEntityController(entity)
+    }
+}
--- a/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/ExtendedPersistentDataContainerFactory.kt
+++ b/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/ExtendedPersistentDataContainerFactory.kt
@@ -0,0 +1,82 @@
+package com.willfp.eco.internal.spigot.proxy.v1_21
+
+import com.willfp.eco.core.data.ExtendedPersistentDataContainer
+import com.willfp.eco.internal.spigot.proxy.ExtendedPersistentDataContainerFactoryProxy
+import net.minecraft.nbt.Tag
+import org.bukkit.Material
+import org.bukkit.craftbukkit.inventory.CraftItemStack
+import org.bukkit.craftbukkit.persistence.CraftPersistentDataContainer
+import org.bukkit.craftbukkit.persistence.CraftPersistentDataTypeRegistry
+import org.bukkit.inventory.ItemStack
+import org.bukkit.persistence.PersistentDataContainer
+import org.bukkit.persistence.PersistentDataType
+
+class ExtendedPersistentDataContainerFactory : ExtendedPersistentDataContainerFactoryProxy {
+    private val registry: CraftPersistentDataTypeRegistry
+
+    init {
+        /*
+         Can't grab actual instance since it's in CraftMetaItem (which is package-private)
+         And getting it would mean more janky reflection
+         */
+        val item = CraftItemStack.asCraftCopy(ItemStack(Material.STONE))
+        val pdc = item.itemMeta!!.persistentDataContainer
+        this.registry = CraftPersistentDataContainer::class.java.getDeclaredField("registry")
+            .apply { isAccessible = true }.get(pdc) as CraftPersistentDataTypeRegistry
+    }
+
+    override fun adapt(pdc: PersistentDataContainer): ExtendedPersistentDataContainer {
+        return when (pdc) {
+            is CraftPersistentDataContainer -> EcoPersistentDataContainer(pdc)
+            else -> throw IllegalArgumentException("Custom PDC instance ${pdc::class.java.name} is not supported!")
+        }
+    }
+
+    override fun newPdc(): PersistentDataContainer {
+        return CraftPersistentDataContainer(registry)
+    }
+
+    inner class EcoPersistentDataContainer(
+        private val handle: CraftPersistentDataContainer
+    ) : ExtendedPersistentDataContainer {
+        @Suppress("UNCHECKED_CAST")
+        private val customDataTags: MutableMap<String, Tag> =
+            CraftPersistentDataContainer::class.java.getDeclaredField("customDataTags")
+                .apply { isAccessible = true }.get(handle) as MutableMap<String, Tag>
+
+        override fun <T : Any, Z : Any> set(key: String, dataType: PersistentDataType<T, Z>, value: Z) {
+            customDataTags[key] =
+                registry.wrap(dataType, dataType.toPrimitive(value, handle.adapterContext))
+        }
+
+        override fun <T : Any, Z : Any> has(key: String, dataType: PersistentDataType<T, Z>): Boolean {
+            val value = customDataTags[key] ?: return false
+            return registry.isInstanceOf(dataType, value)
+        }
+
+        override fun <T : Any, Z : Any> get(key: String, dataType: PersistentDataType<T, Z>): Z? {
+            val value = customDataTags[key] ?: return null
+            return dataType.fromPrimitive(registry.extract<T, Tag>(dataType, value), handle.adapterContext)
+        }
+
+        override fun <T : Any, Z : Any> getOrDefault(
+            key: String,
+            dataType: PersistentDataType<T, Z>,
+            defaultValue: Z
+        ): Z {
+            return get(key, dataType) ?: defaultValue
+        }
+
+        override fun remove(key: String) {
+            customDataTags.remove(key)
+        }
+
+        override fun getAllKeys(): MutableSet<String> {
+            return customDataTags.keys
+        }
+
+        override fun getBase(): PersistentDataContainer {
+            return handle
+        }
+    }
+}
--- a/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/FastItemStackFactory.kt
+++ b/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/FastItemStackFactory.kt
@@ -0,0 +1,392 @@
+package com.willfp.eco.internal.spigot.proxy.v1_21
+
+import com.willfp.eco.core.fast.FastItemStack
+import com.willfp.eco.internal.spigot.proxy.FastItemStackFactoryProxy
+import com.willfp.eco.internal.spigot.proxy.common.asNMSStack
+import com.willfp.eco.internal.spigot.proxy.common.item.ContinuallyAppliedPersistentDataContainer
+import com.willfp.eco.internal.spigot.proxy.common.item.ImplementedFIS
+import com.willfp.eco.internal.spigot.proxy.common.makePdc
+import com.willfp.eco.internal.spigot.proxy.common.mergeIfNeeded
+import com.willfp.eco.internal.spigot.proxy.common.setPdc
+import com.willfp.eco.internal.spigot.proxy.common.toAdventure
+import com.willfp.eco.internal.spigot.proxy.common.toItem
+import com.willfp.eco.internal.spigot.proxy.common.toMaterial
+import com.willfp.eco.internal.spigot.proxy.common.toNMS
+import com.willfp.eco.util.StringUtils
+import com.willfp.eco.util.toComponent
+import com.willfp.eco.util.toLegacy
+import net.kyori.adventure.text.Component
+import net.kyori.adventure.text.format.TextDecoration
+import net.minecraft.core.component.DataComponentType
+import net.minecraft.core.component.DataComponents
+import net.minecraft.nbt.CompoundTag
+import net.minecraft.util.Unit
+import net.minecraft.world.item.component.CustomData
+import net.minecraft.world.item.component.CustomModelData
+import net.minecraft.world.item.component.ItemLore
+import org.bukkit.craftbukkit.CraftRegistry
+import org.bukkit.craftbukkit.enchantments.CraftEnchantment
+import org.bukkit.enchantments.Enchantment
+import org.bukkit.inventory.ItemFlag
+import org.bukkit.inventory.ItemStack
+import org.bukkit.persistence.PersistentDataContainer
+import kotlin.math.max
+
+private val unstyledComponent = Component.empty().style {
+    it.color(null).decoration(TextDecoration.ITALIC, false)
+}
+
+class FastItemStackFactory : FastItemStackFactoryProxy {
+    override fun create(itemStack: ItemStack): FastItemStack {
+        return NewEcoFastItemStack(itemStack)
+    }
+
+    @Suppress("UsePropertyAccessSyntax")
+    class NewEcoFastItemStack(
+        private val bukkit: ItemStack
+    ) : ImplementedFIS {
+        // Cast is there because, try as I might, I can't get IntellIJ to recognise half the classes in the dev bundle
+        @Suppress("USELESS_CAST")
+        private val handle = bukkit.asNMSStack() as net.minecraft.world.item.ItemStack
+
+        private val pdc = (handle.get(DataComponents.CUSTOM_DATA)?.copyTag() ?: CompoundTag()).makePdc()
+
+        override fun getEnchants(checkStored: Boolean): Map<Enchantment, Int> {
+            val enchantments = handle.get(DataComponents.ENCHANTMENTS) ?: return emptyMap()
+
+            val map = mutableMapOf<Enchantment, Int>()
+
+            for ((enchantment, level) in enchantments.entrySet()) {
+                val bukkit = CraftEnchantment.minecraftToBukkit(enchantment.value())
+
+                map[bukkit] = level
+            }
+
+            return map
+        }
+
+        override fun getEnchantmentLevel(
+            enchantment: Enchantment,
+            checkStored: Boolean
+        ): Int {
+            val minecraft = CraftRegistry
+                .bukkitToMinecraft<Enchantment, net.minecraft.world.item.enchantment.Enchantment>(enchantment)
+
+            val enchantments = handle.get(DataComponents.ENCHANTMENTS) ?: return 0
+            var level = enchantments.getLevel(minecraft)
+
+            if (checkStored) {
+                val storedEnchantments = handle.get(DataComponents.STORED_ENCHANTMENTS) ?: return 0
+                level = max(level, storedEnchantments.getLevel(minecraft))
+            }
+
+            return level
+        }
+
+        override fun setLore(lore: List<String>?) = setLoreComponents(lore?.map { it.toComponent() })
+
+        override fun setLoreComponents(lore: List<Component>?) {
+            if (lore == null) {
+                handle.set<ItemLore>(DataComponents.LORE, null)
+            } else {
+                val components = lore
+                    .map { unstyledComponent.append(it) }
+                    .map { it.toNMS() }
+
+                handle.set(
+                    DataComponents.LORE, ItemLore(
+                        components,
+                        components
+                    )
+                )
+            }
+
+            apply()
+        }
+
+        override fun getLoreComponents(): List<Component> {
+            return handle.get(DataComponents.LORE)?.lines?.map { it.toAdventure() } ?: emptyList()
+        }
+
+        override fun getLore(): List<String> =
+            getLoreComponents().map { StringUtils.toLegacy(it) }
+
+        override fun setDisplayName(name: Component?) {
+            if (name == null) {
+                handle.set<net.minecraft.network.chat.Component>(DataComponents.CUSTOM_NAME, null)
+            } else {
+                handle.set(DataComponents.CUSTOM_NAME, name.toNMS())
+            }
+
+            apply()
+        }
+
+        override fun setDisplayName(name: String?) = setDisplayName(name?.toComponent())
+
+        override fun getDisplayNameComponent(): Component {
+            return handle.get(DataComponents.CUSTOM_NAME)?.toAdventure()
+                ?: Component.translatable(bukkit.type.toItem().getDescriptionId())
+        }
+
+        override fun getDisplayName(): String = displayNameComponent.toLegacy()
+
+        private fun <T> net.minecraft.world.item.ItemStack.modifyComponent(
+            component: DataComponentType<T>,
+            modifier: (T) -> T
+        ) {
+            val current = handle.get(component) ?: return
+            this.set(component, modifier(current))
+        }
+
+        override fun addItemFlags(vararg hideFlags: ItemFlag) {
+            for (flag in hideFlags) {
+                when (flag) {
+                    ItemFlag.HIDE_ENCHANTS -> {
+                        handle.modifyComponent(DataComponents.ENCHANTMENTS) { enchantments ->
+                            enchantments.withTooltip(false)
+                        }
+                    }
+
+                    ItemFlag.HIDE_ATTRIBUTES -> {
+                        handle.modifyComponent(DataComponents.ATTRIBUTE_MODIFIERS) { attributes ->
+                            attributes.withTooltip(false)
+                        }
+                    }
+
+                    ItemFlag.HIDE_UNBREAKABLE -> {
+                        handle.modifyComponent(DataComponents.UNBREAKABLE) { unbreakable ->
+                            unbreakable.withTooltip(false)
+                        }
+                    }
+
+                    ItemFlag.HIDE_DESTROYS -> {
+                        handle.modifyComponent(DataComponents.CAN_BREAK) { destroys ->
+                            destroys.withTooltip(false)
+                        }
+                    }
+
+                    ItemFlag.HIDE_PLACED_ON -> {
+                        handle.modifyComponent(DataComponents.CAN_PLACE_ON) { placedOn ->
+                            placedOn.withTooltip(false)
+                        }
+                    }
+
+                    ItemFlag.HIDE_ADDITIONAL_TOOLTIP -> {
+                        handle.set(DataComponents.HIDE_ADDITIONAL_TOOLTIP, Unit.INSTANCE)
+                    }
+
+                    ItemFlag.HIDE_DYE -> {
+                        handle.modifyComponent(DataComponents.DYED_COLOR) { dyed ->
+                            dyed.withTooltip(false)
+                        }
+                    }
+
+                    ItemFlag.HIDE_ARMOR_TRIM -> {
+                        handle.modifyComponent(DataComponents.TRIM) { trim ->
+                            trim.withTooltip(false)
+                        }
+                    }
+
+                    ItemFlag.HIDE_STORED_ENCHANTS -> {
+                        handle.modifyComponent(DataComponents.STORED_ENCHANTMENTS) { storedEnchants ->
+                            storedEnchants.withTooltip(false)
+                        }
+                    }
+                }
+            }
+
+            apply()
+        }
+
+        override fun removeItemFlags(vararg hideFlags: ItemFlag) {
+            for (flag in hideFlags) {
+                when (flag) {
+                    ItemFlag.HIDE_ENCHANTS -> {
+                        handle.modifyComponent(DataComponents.ENCHANTMENTS) { enchantments ->
+                            enchantments.withTooltip(true)
+                        }
+                    }
+
+                    ItemFlag.HIDE_ATTRIBUTES -> {
+                        handle.modifyComponent(DataComponents.ATTRIBUTE_MODIFIERS) { attributes ->
+                            attributes.withTooltip(true)
+                        }
+                    }
+
+                    ItemFlag.HIDE_UNBREAKABLE -> {
+                        handle.modifyComponent(DataComponents.UNBREAKABLE) { unbreakable ->
+                            unbreakable.withTooltip(true)
+                        }
+                    }
+
+                    ItemFlag.HIDE_DESTROYS -> {
+                        handle.modifyComponent(DataComponents.CAN_BREAK) { destroys ->
+                            destroys.withTooltip(true)
+                        }
+                    }
+
+                    ItemFlag.HIDE_PLACED_ON -> {
+                        handle.modifyComponent(DataComponents.CAN_PLACE_ON) { placedOn ->
+                            placedOn.withTooltip(true)
+                        }
+                    }
+
+                    ItemFlag.HIDE_ADDITIONAL_TOOLTIP -> {
+                        handle.remove(DataComponents.HIDE_ADDITIONAL_TOOLTIP)
+                    }
+
+                    ItemFlag.HIDE_DYE -> {
+                        handle.modifyComponent(DataComponents.DYED_COLOR) { dyed ->
+                            dyed.withTooltip(true)
+                        }
+                    }
+
+                    ItemFlag.HIDE_ARMOR_TRIM -> {
+                        handle.modifyComponent(DataComponents.TRIM) { trim ->
+                            trim.withTooltip(true)
+                        }
+                    }
+
+                    ItemFlag.HIDE_STORED_ENCHANTS -> {
+                        handle.modifyComponent(DataComponents.STORED_ENCHANTMENTS) { storedEnchants ->
+                            storedEnchants.withTooltip(true)
+                        }
+                    }
+                }
+            }
+
+            apply()
+        }
+
+        override fun getItemFlags(): Set<ItemFlag> {
+            val currentFlags = mutableSetOf<ItemFlag>()
+            for (f in ItemFlag.values()) {
+                if (hasItemFlag(f)) {
+                    currentFlags.add(f)
+                }
+            }
+            return currentFlags
+        }
+
+        override fun hasItemFlag(flag: ItemFlag): Boolean {
+            return when (flag) {
+                ItemFlag.HIDE_ENCHANTS -> {
+                    val enchantments = handle.get(DataComponents.ENCHANTMENTS) ?: return false
+                    !enchantments.showInTooltip
+                }
+
+                ItemFlag.HIDE_ATTRIBUTES -> {
+                    val attributes = handle.get(DataComponents.ATTRIBUTE_MODIFIERS) ?: return false
+                    !attributes.showInTooltip
+                }
+
+                ItemFlag.HIDE_UNBREAKABLE -> {
+                    val unbreakable = handle.get(DataComponents.UNBREAKABLE) ?: return false
+                    !unbreakable.showInTooltip
+                }
+
+                ItemFlag.HIDE_DESTROYS -> {
+                    val destroys = handle.get(DataComponents.CAN_BREAK) ?: return false
+                    !destroys.showInTooltip()
+                }
+
+                ItemFlag.HIDE_PLACED_ON -> {
+                    val placedOn = handle.get(DataComponents.CAN_PLACE_ON) ?: return false
+                    !placedOn.showInTooltip()
+                }
+
+                ItemFlag.HIDE_ADDITIONAL_TOOLTIP -> {
+                    handle.get(DataComponents.HIDE_ADDITIONAL_TOOLTIP) != null
+                }
+
+                ItemFlag.HIDE_DYE -> {
+                    val dyed = handle.get(DataComponents.DYED_COLOR) ?: return false
+                    !dyed.showInTooltip()
+                }
+
+                ItemFlag.HIDE_ARMOR_TRIM -> {
+                    val armorTrim = handle.get(DataComponents.TRIM) ?: return false
+                    !armorTrim.showInTooltip
+                }
+
+                ItemFlag.HIDE_STORED_ENCHANTS -> {
+                    val storedEnchants = handle.get(DataComponents.STORED_ENCHANTMENTS) ?: return false
+                    !storedEnchants.showInTooltip
+                }
+            }
+        }
+
+        override fun getRepairCost(): Int {
+            return handle.get(DataComponents.REPAIR_COST) ?: 0
+        }
+
+        override fun setRepairCost(cost: Int) {
+            handle.set(DataComponents.REPAIR_COST, cost)
+
+            apply()
+        }
+
+        override fun getPersistentDataContainer(): PersistentDataContainer {
+            return ContinuallyAppliedPersistentDataContainer(this.pdc, this)
+        }
+
+        override fun getAmount(): Int = handle.getCount()
+
+        override fun setAmount(amount: Int) {
+            handle.setCount(amount)
+            apply()
+        }
+
+        override fun setType(material: org.bukkit.Material) {
+            @Suppress("DEPRECATION")
+            handle.setItem(material.toItem())
+            apply()
+        }
+
+        override fun getType(): org.bukkit.Material = handle.getItem().toMaterial()
+
+        override fun getCustomModelData(): Int? =
+            handle.get(DataComponents.CUSTOM_MODEL_DATA)?.value
+
+        override fun setCustomModelData(data: Int?) {
+            if (data == null) {
+                handle.remove(DataComponents.CUSTOM_MODEL_DATA)
+            } else {
+                handle.set(DataComponents.CUSTOM_MODEL_DATA, CustomModelData(data))
+            }
+
+            apply()
+        }
+
+        override fun equals(other: Any?): Boolean {
+            if (other !is NewEcoFastItemStack) {
+                return false
+            }
+
+            return other.hashCode() == this.hashCode()
+        }
+
+        override fun hashCode(): Int {
+            return net.minecraft.world.item.ItemStack.hashItemAndComponents(handle)
+        }
+
+        override fun apply() {
+            val customData = handle.getOrDefault(DataComponents.CUSTOM_DATA, CustomData.EMPTY)
+            val updated = customData.update {
+                it.setPdc(pdc)
+            }
+
+            if (updated.isEmpty) {
+                handle.remove(DataComponents.CUSTOM_DATA)
+            } else {
+                handle.set(DataComponents.CUSTOM_DATA, updated)
+            }
+
+            bukkit.mergeIfNeeded(handle)
+        }
+
+        override fun unwrap(): ItemStack {
+            return bukkit
+        }
+    }
+}
--- a/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/MiniMessageTranslator.kt
+++ b/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/MiniMessageTranslator.kt
@@ -0,0 +1,33 @@
+package com.willfp.eco.internal.spigot.proxy.v1_21
+
+import com.willfp.eco.core.display.Display
+import com.willfp.eco.internal.spigot.proxy.MiniMessageTranslatorProxy
+import com.willfp.eco.util.toLegacy
+import net.kyori.adventure.text.minimessage.MiniMessage
+
+class MiniMessageTranslator : MiniMessageTranslatorProxy {
+    override fun format(message: String): String {
+        var mut = message
+
+        val startsWithPrefix = mut.startsWith(Display.PREFIX)
+        if (startsWithPrefix) {
+            mut = mut.substring(2)
+        }
+
+        mut = mut.replace('§', '&')
+
+        val miniMessage = runCatching {
+            MiniMessage.miniMessage().deserialize(
+                mut
+            ).toLegacy()
+        }.getOrNull() ?: mut
+
+        mut = if (startsWithPrefix) {
+            Display.PREFIX + miniMessage
+        } else {
+            miniMessage
+        }
+
+        return mut
+    }
+}
--- a/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/PacketHandler.kt
+++ b/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/PacketHandler.kt
@@ -0,0 +1,46 @@
+package com.willfp.eco.internal.spigot.proxy.v1_21
+
+import com.willfp.eco.core.EcoPlugin
+import com.willfp.eco.core.packet.PacketListener
+import com.willfp.eco.internal.spigot.proxy.PacketHandlerProxy
+import com.willfp.eco.internal.spigot.proxy.common.packet.display.PacketAutoRecipe
+import com.willfp.eco.internal.spigot.proxy.common.packet.display.PacketHeldItemSlot
+import com.willfp.eco.internal.spigot.proxy.common.packet.display.PacketSetSlot
+import com.willfp.eco.internal.spigot.proxy.common.packet.display.PacketWindowItems
+import com.willfp.eco.internal.spigot.proxy.common.packet.display.frame.clearFrames
+import com.willfp.eco.internal.spigot.proxy.v1_21.packet.NewItemsPacketOpenWindowMerchant
+import com.willfp.eco.internal.spigot.proxy.v1_21.packet.NewItemsPacketSetCreativeSlot
+import net.minecraft.network.protocol.Packet
+import org.bukkit.craftbukkit.entity.CraftPlayer
+import org.bukkit.entity.Player
+
+class PacketHandler : PacketHandlerProxy {
+    override fun sendPacket(player: Player, packet: com.willfp.eco.core.packet.Packet) {
+        if (player !is CraftPlayer) {
+            return
+        }
+
+        val handle = packet.handle
+
+        if (handle !is Packet<*>) {
+            return
+        }
+
+        player.handle.connection.send(handle)
+    }
+
+    override fun clearDisplayFrames() {
+        clearFrames()
+    }
+
+    override fun getPacketListeners(plugin: EcoPlugin): List<PacketListener> {
+        return listOf(
+            PacketAutoRecipe(plugin),
+            PacketHeldItemSlot,
+            NewItemsPacketOpenWindowMerchant,
+            NewItemsPacketSetCreativeSlot,
+            PacketSetSlot,
+            PacketWindowItems(plugin)
+        )
+    }
+}
--- a/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/SNBTConverter.kt
+++ b/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/SNBTConverter.kt
@@ -0,0 +1,80 @@
+package com.willfp.eco.internal.spigot.proxy.v1_21
+
+import com.mojang.serialization.Dynamic
+import com.willfp.eco.core.items.TestableItem
+import com.willfp.eco.core.recipe.parts.EmptyTestableItem
+import com.willfp.eco.internal.spigot.proxy.SNBTConverterProxy
+import net.minecraft.nbt.CompoundTag
+import net.minecraft.nbt.NbtOps
+import net.minecraft.nbt.SnbtPrinterTagVisitor
+import net.minecraft.nbt.TagParser
+import net.minecraft.server.MinecraftServer
+import net.minecraft.util.datafix.fixes.References
+import org.bukkit.Bukkit
+import org.bukkit.craftbukkit.CraftServer
+import org.bukkit.craftbukkit.inventory.CraftItemStack
+import org.bukkit.craftbukkit.util.CraftMagicNumbers
+import org.bukkit.inventory.ItemStack
+
+private val registryAccess = (Bukkit.getServer() as CraftServer).server.registryAccess()
+
+class SNBTConverter : SNBTConverterProxy {
+    private fun parseItemSNBT(snbt: String): CompoundTag? {
+        val nbt = runCatching { TagParser.parseTag(snbt) }.getOrNull() ?: return null
+        val dataVersion = if (nbt.contains("DataVersion")) {
+            nbt.getInt("DataVersion")
+        } else null
+
+        // If the data version is the same as the server's data version, we don't need to fix it
+        if (dataVersion == CraftMagicNumbers.INSTANCE.dataVersion) {
+            return nbt
+        }
+
+        return MinecraftServer.getServer().fixerUpper.update(
+            References.ITEM_STACK,
+            Dynamic(NbtOps.INSTANCE, nbt),
+            dataVersion ?: 3700, // 3700 is the 1.20.4 data version
+            CraftMagicNumbers.INSTANCE.dataVersion
+        ).value as CompoundTag
+    }
+
+    override fun fromSNBT(snbt: String): ItemStack? {
+        val tag = parseItemSNBT(snbt) ?: return null
+        val nms = net.minecraft.world.item.ItemStack.parse(registryAccess, tag).orElse(null) ?: return null
+        return CraftItemStack.asBukkitCopy(nms)
+    }
+
+    override fun toSNBT(itemStack: ItemStack): String {
+        val nms = CraftItemStack.asNMSCopy(itemStack)
+        val tag = nms.save(registryAccess) as CompoundTag
+        tag.putInt("DataVersion", CraftMagicNumbers.INSTANCE.dataVersion)
+        return SnbtPrinterTagVisitor().visit(tag)
+    }
+
+    override fun makeSNBTTestable(snbt: String): TestableItem {
+        val tag = parseItemSNBT(snbt) ?: return EmptyTestableItem()
+        val nms = net.minecraft.world.item.ItemStack.parse(registryAccess, tag).orElse(null)
+            ?: return EmptyTestableItem()
+
+        tag.remove("Count")
+        return SNBTTestableItem(CraftItemStack.asBukkitCopy(nms), tag)
+    }
+
+    class SNBTTestableItem(
+        private val item: ItemStack,
+        private val tag: CompoundTag
+    ) : TestableItem {
+        override fun matches(itemStack: ItemStack?): Boolean {
+            if (itemStack == null) {
+                return false
+            }
+
+            val nms = CraftItemStack.asNMSCopy(itemStack)
+            val nmsTag = nms.save(registryAccess) as CompoundTag
+            nmsTag.remove("Count")
+            return tag.copy().merge(nmsTag) == nmsTag && itemStack.type == item.type
+        }
+
+        override fun getItem(): ItemStack = item
+    }
+}
--- a/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/Skull.kt
+++ b/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/Skull.kt
@@ -0,0 +1,18 @@
+package com.willfp.eco.internal.spigot.proxy.v1_21
+
+import com.willfp.eco.internal.spigot.proxy.SkullProxy
+import com.willfp.eco.internal.spigot.proxy.common.texture
+import org.bukkit.inventory.meta.SkullMeta
+
+class Skull : SkullProxy {
+    override fun setSkullTexture(
+        meta: SkullMeta,
+        base64: String
+    ) {
+        meta.texture = base64
+    }
+
+    override fun getSkullTexture(
+        meta: SkullMeta
+    ): String? = meta.texture
+}
--- a/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/TPS.kt
+++ b/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/TPS.kt
@@ -0,0 +1,11 @@
+package com.willfp.eco.internal.spigot.proxy.v1_21
+
+import com.willfp.eco.internal.spigot.proxy.TPSProxy
+import org.bukkit.Bukkit
+import org.bukkit.craftbukkit.CraftServer
+
+class TPS : TPSProxy {
+    override fun getTPS(): Double {
+        return (Bukkit.getServer() as CraftServer).handle.server.tps1.average
+    }
+}
--- a/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/entity/EcoEntityController.kt
+++ b/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/entity/EcoEntityController.kt
@@ -0,0 +1,95 @@
+package com.willfp.eco.internal.spigot.proxy.v1_21.entity
+
+import com.willfp.eco.core.entities.ai.CustomGoal
+import com.willfp.eco.core.entities.ai.EntityController
+import com.willfp.eco.core.entities.ai.EntityGoal
+import com.willfp.eco.core.entities.ai.TargetGoal
+import com.willfp.eco.internal.spigot.proxy.common.ai.CustomGoalFactory
+import com.willfp.eco.internal.spigot.proxy.common.ai.getGoalFactory
+import com.willfp.eco.internal.spigot.proxy.common.toPathfinderMob
+import net.minecraft.world.entity.PathfinderMob
+import net.minecraft.world.entity.ai.goal.Goal
+import org.bukkit.entity.Mob
+
+class EcoEntityController<T : Mob>(
+    private val handle: T
+) : EntityController<T> {
+    override fun addEntityGoal(priority: Int, goal: EntityGoal<in T>): EntityController<T> {
+        val nms = getNms() ?: return this
+
+        nms.goalSelector.addGoal(
+            priority,
+            goal.getGoalFactory()?.create(goal, nms) ?: return this
+        )
+
+        return this
+    }
+
+    override fun removeEntityGoal(goal: EntityGoal<in T>): EntityController<T> {
+        val nms = getNms() ?: return this
+
+        val predicate: (Goal) -> Boolean = if (goal is CustomGoal<*>) {
+            { CustomGoalFactory.isGoalOfType(it, goal) }
+        } else {
+            { goal.getGoalFactory()?.isGoalOfType(it) == true }
+        }
+
+        for (wrapped in nms.goalSelector.availableGoals.toSet()) {
+            if (predicate(wrapped.goal)) {
+                nms.goalSelector.removeGoal(wrapped.goal)
+            }
+        }
+
+        return this
+    }
+
+    override fun clearEntityGoals(): EntityController<T> {
+        val nms = getNms() ?: return this
+        nms.goalSelector.availableGoals.clear()
+        return this
+    }
+
+    override fun addTargetGoal(priority: Int, goal: TargetGoal<in T>): EntityController<T> {
+        val nms = getNms() ?: return this
+
+        nms.targetSelector.addGoal(
+            priority, goal.getGoalFactory()?.create(goal, nms) ?: return this
+        )
+
+        nms.targetSelector
+
+        return this
+    }
+
+    override fun removeTargetGoal(goal: TargetGoal<in T>): EntityController<T> {
+        val nms = getNms() ?: return this
+
+        val predicate: (Goal) -> Boolean = if (goal is CustomGoal<*>) {
+            { CustomGoalFactory.isGoalOfType(it, goal) }
+        } else {
+            { goal.getGoalFactory()?.isGoalOfType(it) == true }
+        }
+
+        for (wrapped in nms.targetSelector.availableGoals.toSet()) {
+            if (predicate(wrapped.goal)) {
+                nms.targetSelector.removeGoal(wrapped.goal)
+            }
+        }
+
+        return this
+    }
+
+    override fun clearTargetGoals(): EntityController<T> {
+        val nms = getNms() ?: return this
+        nms.targetSelector.availableGoals.clear()
+        return this
+    }
+
+    private fun getNms(): PathfinderMob? {
+        return handle.toPathfinderMob()
+    }
+
+    override fun getEntity(): T {
+        return handle
+    }
+}
--- a/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/packet/NewItemsPacketOpenWindowMerchant.kt
+++ b/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/packet/NewItemsPacketOpenWindowMerchant.kt
@@ -0,0 +1,35 @@
+package com.willfp.eco.internal.spigot.proxy.v1_21.packet
+
+import com.willfp.eco.core.display.Display
+import com.willfp.eco.core.packet.PacketEvent
+import com.willfp.eco.core.packet.PacketListener
+import com.willfp.eco.internal.spigot.proxy.common.asBukkitStack
+import net.minecraft.network.protocol.game.ClientboundMerchantOffersPacket
+import net.minecraft.world.item.trading.MerchantOffers
+
+object NewItemsPacketOpenWindowMerchant : PacketListener {
+    private val field = ClientboundMerchantOffersPacket::class.java
+        .declaredFields
+        .first { it.type == MerchantOffers::class.java }
+        .apply { isAccessible = true }
+
+    override fun onSend(event: PacketEvent) {
+        val packet = event.packet.handle as? ClientboundMerchantOffersPacket ?: return
+
+        val offers = MerchantOffers()
+
+        for (offer in packet.offers) {
+            val new = offer.copy()
+
+            Display.display(new.baseCostA.itemStack.asBukkitStack(), event.player)
+            if (new.costB.isPresent) {
+                Display.display(new.costB.get().itemStack.asBukkitStack(), event.player)
+            }
+            Display.display(new.result.asBukkitStack(), event.player)
+
+            offers += new
+        }
+
+        field.set(packet, offers)
+    }
+}
--- a/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/packet/NewItemsPacketSetCreativeSlot.kt
+++ b/eco-core/core-nms/v1_21/src/main/kotlin/com/willfp/eco/internal/spigot/proxy/v1_21/packet/NewItemsPacketSetCreativeSlot.kt
@@ -0,0 +1,19 @@
+package com.willfp.eco.internal.spigot.proxy.v1_21.packet
+
+import com.willfp.eco.core.display.Display
+import com.willfp.eco.core.packet.PacketEvent
+import com.willfp.eco.core.packet.PacketListener
+import com.willfp.eco.internal.spigot.proxy.common.asBukkitStack
+import com.willfp.eco.internal.spigot.proxy.common.packet.display.frame.DisplayFrame
+import com.willfp.eco.internal.spigot.proxy.common.packet.display.frame.lastDisplayFrame
+import net.minecraft.network.protocol.game.ServerboundSetCreativeModeSlotPacket
+
+object NewItemsPacketSetCreativeSlot : PacketListener {
+    override fun onReceive(event: PacketEvent) {
+        val packet = event.packet.handle as? ServerboundSetCreativeModeSlotPacket ?: return
+
+        Display.revert(packet.itemStack.asBukkitStack())
+
+        event.player.lastDisplayFrame = DisplayFrame.EMPTY
+    }
+}
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -22,6 +22,7 @@ include(":eco-core:core-nms:v1_20_R1")
 include(":eco-core:core-nms:v1_20_R2")
 include(":eco-core:core-nms:v1_20_R3")
 include(":eco-core:core-nms:v1_20_6")
+include(":eco-core:core-nms:v1_21")
 include(":eco-core:core-proxy")
 include(":eco-core:core-plugin")
 include(":eco-core:core-backend")