5.0.1 Release

Fixes #3927

README.md

@@ -11,6 +11,9 @@ The base ViaVersion jar runs on Paper and Velocity. We also have projects integr
 on Fabric, Forge, Bungee, Sponge, or as a standalone proxy to join from basically any client version on
 any server version from the past decade. **See [HERE](https://github.com/ViaVersion) for an overview of the different Via\* projects.**
 
+Note that ViaVersion will be able to **run best on either Paper servers or Fabric clients** due to having
+direct access to client/server state and more extensive API.
+
 Supported Versions:
 
 ![Table (https://i.imgur.com/sTrVnC2.png)](https://i.imgur.com/sTrVnC2.png)
@@ -67,6 +70,8 @@ dependencies {
 If you need access to the existing protocol or platform implementations, use the parent artifact `viaversion`.
 Please note the [differences in licensing](#license).
 
+Note: If you want to make your own platform implementation of ViaVersion (and additional addons),
+you can use the [ViaLoader](https://github.com/ViaVersion/ViaLoader) project.
 
 Building
 --------

api/src/main/java/com/viaversion/viaversion/api/command/ViaVersionCommand.java

@@ -34,6 +34,13 @@ public interface ViaVersionCommand {
      */
     void registerSubCommand(ViaSubCommand command);
 
+    /**
+     * Removes a subcommand by name, can be used to unload default subcommands which are not supported
+     * on the platform.
+     * @param name Subcommand name
+     */
+    void removeSubCommand(String name);
+
     /**
      * Check if a subcommand is registered.
      *

api/src/main/java/com/viaversion/viaversion/api/data/MappingData.java

@@ -52,6 +52,8 @@ public interface MappingData {
      */
     int getNewBlockId(int id);
 
+    int getOldBlockId(int id);
+
     /**
      * Returns the mapped item id, or -1 if unmapped.
      *

api/src/main/java/com/viaversion/viaversion/api/data/MappingDataBase.java

@@ -39,13 +39,13 @@ public class MappingDataBase implements MappingData {
 
     protected final String unmappedVersion;
     protected final String mappedVersion;
-    protected BiMappings itemMappings;
     protected FullMappings argumentTypeMappings;
     protected FullMappings entityMappings;
     protected FullMappings recipeSerializerMappings;
     protected FullMappings itemDataSerializerMappings;
     protected ParticleMappings particleMappings;
-    protected Mappings blockMappings;
+    protected BiMappings itemMappings;
+    protected BiMappings blockMappings;
     protected Mappings blockStateMappings;
     protected Mappings blockEntityMappings;
     protected Mappings soundMappings;
@@ -68,7 +68,7 @@ public class MappingDataBase implements MappingData {
         }
 
         final CompoundTag data = readMappingsFile("mappings-" + unmappedVersion + "to" + mappedVersion + ".nbt");
-        blockMappings = loadMappings(data, "blocks");
+        blockMappings = loadBiMappings(data, "blocks");
         blockStateMappings = loadMappings(data, "blockstates");
         blockEntityMappings = loadMappings(data, "blockentities");
         soundMappings = loadMappings(data, "sounds");
@@ -178,6 +178,11 @@ public class MappingDataBase implements MappingData {
         return checkValidity(id, blockMappings.getNewId(id), "block");
     }
 
+    @Override
+    public int getOldBlockId(final int id) {
+        return blockMappings.getNewIdOrDefault(id, 1);
+    }
+
     @Override
     public int getNewItemId(final int id) {
         return checkValidity(id, itemMappings.getNewId(id), "item");

api/src/main/java/com/viaversion/viaversion/api/minecraft/GameMode.java

@@ -24,6 +24,7 @@ package com.viaversion.viaversion.api.minecraft;
 
 public enum GameMode {
 
+    NOT_SET(""),
     SURVIVAL("Survival Mode"),
     CREATIVE("Creative Mode"),
     ADVENTURE("Adventure Mode"),
@@ -41,11 +42,11 @@ public enum GameMode {
 
     public static GameMode getById(int id) {
         return switch (id) {
-            case 0 -> SURVIVAL;
+            case -1 -> NOT_SET;
             case 1 -> CREATIVE;
             case 2 -> ADVENTURE;
             case 3 -> SPECTATOR;
-            default -> throw new IllegalArgumentException("Unknown gamemode id: " + id);
+            default /*0*/ -> SURVIVAL;
         };
     }
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/HolderSet.java

@@ -22,6 +22,8 @@
  */
 package com.viaversion.viaversion.api.minecraft;
 
+import it.unimi.dsi.fastutil.ints.Int2IntFunction;
+
 /**
  * Set of ids that either holds a string tag key or an array of ids.
  */
@@ -76,4 +78,12 @@ public interface HolderSet {
      * @return true if this holder set has direct ids, false if it has a tag key
      */
     boolean hasIds();
+
+    /**
+     * Returns a new holder set with the ids rewritten.
+     *
+     * @param idRewriter the id rewriter
+     * @return a new holder set with the ids rewritten, or self if it has a tag key
+     */
+    HolderSet rewrite(Int2IntFunction idRewriter);
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/HolderSetImpl.java

@@ -23,6 +23,7 @@
 package com.viaversion.viaversion.api.minecraft;
 
 import com.viaversion.viaversion.util.EitherImpl;
+import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 
 final class HolderSetImpl extends EitherImpl<String, int[]> implements HolderSet {
 
@@ -53,4 +54,18 @@ final class HolderSetImpl extends EitherImpl<String, int[]> implements HolderSet
     public boolean hasIds() {
         return isRight();
     }
+
+    @Override
+    public HolderSet rewrite(final Int2IntFunction idRewriter) {
+        if (hasTagKey()) {
+            return this;
+        }
+
+        final int[] ids = ids();
+        final int[] mappedIds = new int[ids.length];
+        for (int i = 0; i < mappedIds.length; i++) {
+            mappedIds[i] = idRewriter.apply(ids[i]);
+        }
+        return new HolderSetImpl(mappedIds);
+    }
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/PaintingVariant.java

@@ -20,32 +20,28 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-package com.viaversion.viaversion.api.minecraft.item.data;
+package com.viaversion.viaversion.api.minecraft;
 
-import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.api.type.types.misc.HolderType;
 import io.netty.buffer.ByteBuf;
-import java.util.UUID;
 
-public record ModifierData(UUID uuid, String name, double amount, int operation) {
+public record PaintingVariant(int width, int height, String assetId) {
 
-    public static final Type<ModifierData> TYPE = new Type<>(ModifierData.class) {
+    public static HolderType<PaintingVariant> TYPE = new HolderType<>() {
         @Override
-        public ModifierData read(final ByteBuf buffer) {
-            final UUID uuid = Types.UUID.read(buffer);
-            final String name = Types.STRING.read(buffer);
-            final double amount = buffer.readDouble();
-            final int operation = Types.VAR_INT.readPrimitive(buffer);
-            return new ModifierData(uuid, name, amount, operation);
+        public PaintingVariant readDirect(final ByteBuf buffer) {
+            final int width = Types.VAR_INT.readPrimitive(buffer);
+            final int height = Types.VAR_INT.readPrimitive(buffer);
+            final String assetId = Types.STRING.read(buffer);
+            return new PaintingVariant(width, height, assetId);
         }
 
         @Override
-        public void write(final ByteBuf buffer, final ModifierData value) {
-            Types.UUID.write(buffer, value.uuid);
-            Types.STRING.write(buffer, value.name);
-            buffer.writeDouble(value.amount);
-            Types.VAR_INT.writePrimitive(buffer, value.operation);
+        public void writeDirect(final ByteBuf buffer, final PaintingVariant variant) {
+            Types.VAR_INT.writePrimitive(buffer, variant.width());
+            Types.VAR_INT.writePrimitive(buffer, variant.height());
+            Types.STRING.write(buffer, variant.assetId());
         }
     };
-
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/RegistryEntry.java

@@ -25,6 +25,12 @@ package com.viaversion.viaversion.api.minecraft;
 import com.viaversion.nbt.tag.Tag;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
+/**
+ * Represents an entry in a registry.
+ *
+ * @param key key of the registry entry
+ * @param tag data of the registry entry, or null if the client should use its default
+ */
 public record RegistryEntry(String key, @Nullable Tag tag) {
 
     public RegistryEntry withKey(final String key) {

api/src/main/java/com/viaversion/viaversion/api/minecraft/RegistryType.java

@@ -32,7 +32,8 @@ public enum RegistryType {
     ITEM("item"),
     FLUID("fluid"),
     ENTITY("entity_type"),
-    GAME_EVENT("game_event");
+    GAME_EVENT("game_event"),
+    ENCHANTMENT("enchantment");
 
     private static final Map<String, RegistryType> MAP = new HashMap<>();
     private static final RegistryType[] VALUES = values();

api/src/main/java/com/viaversion/viaversion/api/minecraft/WolfVariant.java

@@ -20,31 +20,30 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-package com.viaversion.viaversion.api.minecraft.item.data;
+package com.viaversion.viaversion.api.minecraft;
 
-import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
-import com.viaversion.viaversion.api.type.types.ArrayType;
+import com.viaversion.viaversion.api.type.types.misc.HolderType;
 import io.netty.buffer.ByteBuf;
 
-public record AttributeModifier(int attribute, ModifierData modifier, int slotType) {
+public record WolfVariant(String wildTexture, String tameTexture, String angryTexture, HolderSet biomes) {
 
-    public static final Type<AttributeModifier> TYPE = new Type<>(AttributeModifier.class) {
+    public static HolderType<WolfVariant> TYPE = new HolderType<>() {
         @Override
-        public AttributeModifier read(final ByteBuf buffer) {
-            final int attribute = Types.VAR_INT.readPrimitive(buffer);
-            final ModifierData modifier = ModifierData.TYPE.read(buffer);
-            final int slot = Types.VAR_INT.readPrimitive(buffer);
-            return new AttributeModifier(attribute, modifier, slot);
+        public WolfVariant readDirect(final ByteBuf buffer) {
+            final String wildTexture = Types.STRING.read(buffer);
+            final String tameTexture = Types.STRING.read(buffer);
+            final String angryTexture = Types.STRING.read(buffer);
+            final HolderSet biomes = Types.HOLDER_SET.read(buffer);
+            return new WolfVariant(wildTexture, tameTexture, angryTexture, biomes);
         }
 
         @Override
-        public void write(final ByteBuf buffer, final AttributeModifier value) {
-            Types.VAR_INT.writePrimitive(buffer, value.attribute);
-            ModifierData.TYPE.write(buffer, value.modifier);
-            Types.VAR_INT.writePrimitive(buffer, value.slotType);
+        public void writeDirect(final ByteBuf buffer, final WolfVariant variant) {
+            Types.STRING.write(buffer, variant.wildTexture());
+            Types.STRING.write(buffer, variant.tameTexture());
+            Types.STRING.write(buffer, variant.angryTexture());
+            Types.HOLDER_SET.write(buffer, variant.biomes());
         }
     };
-    public static final Type<AttributeModifier[]> ARRAY_TYPE = new ArrayType<>(TYPE);
-
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/data/StructuredDataContainer.java

@@ -27,6 +27,7 @@ import com.viaversion.viaversion.api.Via;
 import com.viaversion.viaversion.api.data.FullMappings;
 import com.viaversion.viaversion.api.protocol.Protocol;
 import com.viaversion.viaversion.util.Unit;
+import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 import it.unimi.dsi.fastutil.objects.Reference2ObjectOpenHashMap;
 import java.util.Map;
 import java.util.function.Function;
@@ -98,6 +99,24 @@ public final class StructuredDataContainer {
         return empty;
     }
 
+    /**
+     * Updates and returns the structured data by id if not empty.
+     *
+     * @param key             serializer id
+     * @param mappingFunction function to update existing data
+     * @param <T>             data type
+     * @return updated structured data if not empty
+     */
+    public <T> @Nullable StructuredData<T> updateIfPresent(final StructuredDataKey<T> key, final Function<T, T> mappingFunction) {
+        final StructuredData<T> data = this.getNonEmpty(key);
+        if (data == null) {
+            return null;
+        }
+
+        data.setValue(mappingFunction.apply(data.value()));
+        return data;
+    }
+
     public <T> void set(final StructuredDataKey<T> key, final T value) {
         final int id = serializerId(key);
         if (id != -1) {
@@ -105,6 +124,23 @@ public final class StructuredDataContainer {
         }
     }
 
+    public <T> void replaceKey(final StructuredDataKey<T> key, final StructuredDataKey<T> toKey) {
+        replace(key, toKey, Function.identity());
+    }
+
+    public <T, V> void replace(final StructuredDataKey<T> key, final StructuredDataKey<V> toKey, final Function<T, V> valueMapper) {
+        final StructuredData<T> data = remove(key);
+        if (data == null) {
+            return;
+        }
+
+        if (data.isPresent()) {
+            set(toKey, valueMapper.apply(data.value()));
+        } else {
+            addEmpty(toKey);
+        }
+    }
+
     public void set(final StructuredDataKey<Unit> key) {
         this.set(key, Unit.INSTANCE);
     }
@@ -143,6 +179,17 @@ public final class StructuredDataContainer {
         this.mappedNames = mappedNames;
     }
 
+    public void updateIds(final Protocol<?, ?, ?, ?> protocol, final Int2IntFunction rewriter) {
+        for (final StructuredData<?> data : data.values()) {
+            final int mappedId = rewriter.applyAsInt(data.id());
+            if (mappedId == -1) {
+                continue;
+            }
+
+            data.setId(mappedId);
+        }
+    }
+
     public StructuredDataContainer copy() {
         final StructuredDataContainer copy = new StructuredDataContainer(new Reference2ObjectOpenHashMap<>(data));
         copy.lookup = this.lookup;

api/src/main/java/com/viaversion/viaversion/api/minecraft/data/StructuredDataKey.java

@@ -29,7 +29,8 @@ import com.viaversion.viaversion.api.minecraft.Holder;
 import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.minecraft.item.data.AdventureModePredicate;
 import com.viaversion.viaversion.api.minecraft.item.data.ArmorTrim;
-import com.viaversion.viaversion.api.minecraft.item.data.AttributeModifiers;
+import com.viaversion.viaversion.api.minecraft.item.data.AttributeModifiers1_20_5;
+import com.viaversion.viaversion.api.minecraft.item.data.AttributeModifiers1_21;
 import com.viaversion.viaversion.api.minecraft.item.data.BannerPatternLayer;
 import com.viaversion.viaversion.api.minecraft.item.data.Bee;
 import com.viaversion.viaversion.api.minecraft.item.data.BlockStateProperties;
@@ -40,6 +41,7 @@ import com.viaversion.viaversion.api.minecraft.item.data.FireworkExplosion;
 import com.viaversion.viaversion.api.minecraft.item.data.Fireworks;
 import com.viaversion.viaversion.api.minecraft.item.data.FoodProperties;
 import com.viaversion.viaversion.api.minecraft.item.data.Instrument;
+import com.viaversion.viaversion.api.minecraft.item.data.JukeboxPlayable;
 import com.viaversion.viaversion.api.minecraft.item.data.LodestoneTracker;
 import com.viaversion.viaversion.api.minecraft.item.data.PotDecorations;
 import com.viaversion.viaversion.api.minecraft.item.data.PotionContents;
@@ -50,6 +52,7 @@ import com.viaversion.viaversion.api.minecraft.item.data.WrittenBook;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
 import com.viaversion.viaversion.api.type.types.version.Types1_20_5;
+import com.viaversion.viaversion.api.type.types.version.Types1_21;
 import com.viaversion.viaversion.util.Unit;
 
 public record StructuredDataKey<T>(String identifier, Type<T> type) {
@@ -66,7 +69,8 @@ public record StructuredDataKey<T>(String identifier, Type<T> type) {
     public static final StructuredDataKey<Enchantments> ENCHANTMENTS = new StructuredDataKey<>("enchantments", Enchantments.TYPE);
     public static final StructuredDataKey<AdventureModePredicate> CAN_PLACE_ON = new StructuredDataKey<>("can_place_on", AdventureModePredicate.TYPE);
     public static final StructuredDataKey<AdventureModePredicate> CAN_BREAK = new StructuredDataKey<>("can_break", AdventureModePredicate.TYPE);
-    public static final StructuredDataKey<AttributeModifiers> ATTRIBUTE_MODIFIERS = new StructuredDataKey<>("attribute_modifiers", AttributeModifiers.TYPE);
+    public static final StructuredDataKey<AttributeModifiers1_20_5> ATTRIBUTE_MODIFIERS1_20_5 = new StructuredDataKey<>("attribute_modifiers", AttributeModifiers1_20_5.TYPE);
+    public static final StructuredDataKey<AttributeModifiers1_21> ATTRIBUTE_MODIFIERS1_21 = new StructuredDataKey<>("attribute_modifiers", AttributeModifiers1_21.TYPE);
     public static final StructuredDataKey<Integer> CUSTOM_MODEL_DATA = new StructuredDataKey<>("custom_model_data", Types.VAR_INT);
     public static final StructuredDataKey<Unit> HIDE_ADDITIONAL_TOOLTIP = new StructuredDataKey<>("hide_additional_tooltip", Types.EMPTY);
     public static final StructuredDataKey<Unit> HIDE_TOOLTIP = new StructuredDataKey<>("hide_tooltip", Types.EMPTY);
@@ -74,7 +78,8 @@ public record StructuredDataKey<T>(String identifier, Type<T> type) {
     public static final StructuredDataKey<Unit> CREATIVE_SLOT_LOCK = new StructuredDataKey<>("creative_slot_lock", Types.EMPTY);
     public static final StructuredDataKey<Boolean> ENCHANTMENT_GLINT_OVERRIDE = new StructuredDataKey<>("enchantment_glint_override", Types.BOOLEAN);
     public static final StructuredDataKey<Tag> INTANGIBLE_PROJECTILE = new StructuredDataKey<>("intangible_projectile", Types.TAG); // Doesn't actually hold data
-    public static final StructuredDataKey<FoodProperties> FOOD = new StructuredDataKey<>("food", FoodProperties.TYPE);
+    public static final StructuredDataKey<FoodProperties> FOOD1_20_5 = new StructuredDataKey<>("food", FoodProperties.TYPE1_20_5);
+    public static final StructuredDataKey<FoodProperties> FOOD1_21 = new StructuredDataKey<>("food", FoodProperties.TYPE1_21);
     public static final StructuredDataKey<Unit> FIRE_RESISTANT = new StructuredDataKey<>("fire_resistant", Types.EMPTY);
     public static final StructuredDataKey<ToolProperties> TOOL = new StructuredDataKey<>("tool", ToolProperties.TYPE);
     public static final StructuredDataKey<Enchantments> STORED_ENCHANTMENTS = new StructuredDataKey<>("stored_enchantments", Enchantments.TYPE);
@@ -83,8 +88,10 @@ public record StructuredDataKey<T>(String identifier, Type<T> type) {
     public static final StructuredDataKey<Integer> MAP_ID = new StructuredDataKey<>("map_id", Types.VAR_INT);
     public static final StructuredDataKey<CompoundTag> MAP_DECORATIONS = new StructuredDataKey<>("map_decorations", Types.COMPOUND_TAG);
     public static final StructuredDataKey<Integer> MAP_POST_PROCESSING = new StructuredDataKey<>("map_post_processing", Types.VAR_INT);
-    public static final StructuredDataKey<Item[]> CHARGED_PROJECTILES = new StructuredDataKey<>("charged_projectiles", Types1_20_5.ITEM_ARRAY);
-    public static final StructuredDataKey<Item[]> BUNDLE_CONTENTS = new StructuredDataKey<>("bundle_contents", Types1_20_5.ITEM_ARRAY);
+    public static final StructuredDataKey<Item[]> CHARGED_PROJECTILES1_20_5 = new StructuredDataKey<>("charged_projectiles", Types1_20_5.ITEM_ARRAY);
+    public static final StructuredDataKey<Item[]> CHARGED_PROJECTILES1_21 = new StructuredDataKey<>("charged_projectiles", Types1_21.ITEM_ARRAY);
+    public static final StructuredDataKey<Item[]> BUNDLE_CONTENTS1_20_5 = new StructuredDataKey<>("bundle_contents", Types1_20_5.ITEM_ARRAY);
+    public static final StructuredDataKey<Item[]> BUNDLE_CONTENTS1_21 = new StructuredDataKey<>("bundle_contents", Types1_21.ITEM_ARRAY);
     public static final StructuredDataKey<PotionContents> POTION_CONTENTS = new StructuredDataKey<>("potion_contents", PotionContents.TYPE);
     public static final StructuredDataKey<SuspiciousStewEffect[]> SUSPICIOUS_STEW_EFFECTS = new StructuredDataKey<>("suspicious_stew_effects", SuspiciousStewEffect.ARRAY_TYPE);
     public static final StructuredDataKey<FilterableString[]> WRITABLE_BOOK_CONTENT = new StructuredDataKey<>("writable_book_content", FilterableString.ARRAY_TYPE);
@@ -96,6 +103,7 @@ public record StructuredDataKey<T>(String identifier, Type<T> type) {
     public static final StructuredDataKey<CompoundTag> BLOCK_ENTITY_DATA = new StructuredDataKey<>("block_entity_data", Types.COMPOUND_TAG);
     public static final StructuredDataKey<Holder<Instrument>> INSTRUMENT = new StructuredDataKey<>("instrument", Instrument.TYPE);
     public static final StructuredDataKey<Integer> OMINOUS_BOTTLE_AMPLIFIER = new StructuredDataKey<>("ominous_bottle_amplifier", Types.VAR_INT);
+    public static final StructuredDataKey<JukeboxPlayable> JUKEBOX_PLAYABLE = new StructuredDataKey<>("jukebox_playable", JukeboxPlayable.TYPE);
     public static final StructuredDataKey<Tag> RECIPES = new StructuredDataKey<>("recipes", Types.TAG);
     public static final StructuredDataKey<LodestoneTracker> LODESTONE_TRACKER = new StructuredDataKey<>("lodestone_tracker", LodestoneTracker.TYPE);
     public static final StructuredDataKey<FireworkExplosion> FIREWORK_EXPLOSION = new StructuredDataKey<>("firework_explosion", FireworkExplosion.TYPE);
@@ -105,7 +113,8 @@ public record StructuredDataKey<T>(String identifier, Type<T> type) {
     public static final StructuredDataKey<BannerPatternLayer[]> BANNER_PATTERNS = new StructuredDataKey<>("banner_patterns", BannerPatternLayer.ARRAY_TYPE);
     public static final StructuredDataKey<Integer> BASE_COLOR = new StructuredDataKey<>("base_color", Types.VAR_INT);
     public static final StructuredDataKey<PotDecorations> POT_DECORATIONS = new StructuredDataKey<>("pot_decorations", PotDecorations.TYPE);
-    public static final StructuredDataKey<Item[]> CONTAINER = new StructuredDataKey<>("container", Types1_20_5.ITEM_ARRAY);
+    public static final StructuredDataKey<Item[]> CONTAINER1_20_5 = new StructuredDataKey<>("container", Types1_20_5.ITEM_ARRAY);
+    public static final StructuredDataKey<Item[]> CONTAINER1_21 = new StructuredDataKey<>("container", Types1_21.ITEM_ARRAY);
     public static final StructuredDataKey<BlockStateProperties> BLOCK_STATE = new StructuredDataKey<>("block_state", BlockStateProperties.TYPE);
     public static final StructuredDataKey<Bee[]> BEES = new StructuredDataKey<>("bees", Bee.ARRAY_TYPE);
     public static final StructuredDataKey<Tag> LOCK = new StructuredDataKey<>("lock", Types.TAG);

api/src/main/java/com/viaversion/viaversion/api/minecraft/entitydata/types/EntityDataTypes1_21.java

@@ -0,0 +1,73 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2024 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.entitydata.types;
+
+import com.viaversion.viaversion.api.minecraft.PaintingVariant;
+import com.viaversion.viaversion.api.minecraft.Particle;
+import com.viaversion.viaversion.api.minecraft.WolfVariant;
+import com.viaversion.viaversion.api.minecraft.entitydata.EntityDataType;
+import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.api.type.types.ArrayType;
+import com.viaversion.viaversion.api.type.types.misc.ParticleType;
+import com.viaversion.viaversion.api.type.types.version.Types1_21;
+
+public final class EntityDataTypes1_21 extends AbstractEntityDataTypes {
+
+    public final EntityDataType byteType = add(0, Types.BYTE);
+    public final EntityDataType varIntType = add(1, Types.VAR_INT);
+    public final EntityDataType longType = add(2, Types.VAR_LONG);
+    public final EntityDataType floatType = add(3, Types.FLOAT);
+    public final EntityDataType stringType = add(4, Types.STRING);
+    public final EntityDataType componentType = add(5, Types.TAG);
+    public final EntityDataType optionalComponentType = add(6, Types.OPTIONAL_TAG);
+    public final EntityDataType itemType = add(7, Types1_21.ITEM);
+    public final EntityDataType booleanType = add(8, Types.BOOLEAN);
+    public final EntityDataType rotationsType = add(9, Types.ROTATIONS);
+    public final EntityDataType blockPositionType = add(10, Types.BLOCK_POSITION1_14);
+    public final EntityDataType optionalBlockPositionType = add(11, Types.OPTIONAL_POSITION_1_14);
+    public final EntityDataType directionType = add(12, Types.VAR_INT);
+    public final EntityDataType optionalUUIDType = add(13, Types.OPTIONAL_UUID);
+    public final EntityDataType blockStateType = add(14, Types.VAR_INT);
+    public final EntityDataType optionalBlockStateType = add(15, Types.VAR_INT);
+    public final EntityDataType compoundTagType = add(16, Types.COMPOUND_TAG);
+    public final EntityDataType particleType;
+    public final EntityDataType particlesType;
+    public final EntityDataType villagerDatatType = add(19, Types.VILLAGER_DATA);
+    public final EntityDataType optionalVarIntType = add(20, Types.OPTIONAL_VAR_INT);
+    public final EntityDataType poseType = add(21, Types.VAR_INT);
+    public final EntityDataType catVariantType = add(22, Types.VAR_INT);
+    public final EntityDataType wolfVariantType = add(23, WolfVariant.TYPE);
+    public final EntityDataType frogVariantType = add(24, Types.VAR_INT);
+    public final EntityDataType optionalGlobalPosition = add(25, Types.OPTIONAL_GLOBAL_POSITION);
+    public final EntityDataType paintingVariantType = add(26, PaintingVariant.TYPE);
+    public final EntityDataType snifferState = add(27, Types.VAR_INT);
+    public final EntityDataType armadilloState = add(28, Types.VAR_INT);
+    public final EntityDataType vector3FType = add(29, Types.VECTOR3F);
+    public final EntityDataType quaternionType = add(30, Types.QUATERNION);
+
+    public EntityDataTypes1_21(final ParticleType particleType, final ArrayType<Particle> particlesType) {
+        super(31);
+        this.particleType = add(17, particleType);
+        this.particlesType = add(18, particlesType);
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/StructuredItem.java

@@ -46,8 +46,8 @@ public class StructuredItem implements Item {
         return new StructuredItem(0, 0);
     }
 
-    public static StructuredItem[] emptyArray(final int size) {
-        final StructuredItem[] items = new StructuredItem[size];
+    public static Item[] emptyArray(final int size) {
+        final Item[] items = new Item[size];
         for (int i = 0; i < items.length; i++) {
             items[i] = empty();
         }

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/AdventureModePredicate.java

@@ -24,6 +24,7 @@ package com.viaversion.viaversion.api.minecraft.item.data;
 
 import com.viaversion.viaversion.api.type.Type;
 import io.netty.buffer.ByteBuf;
+import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 
 public record AdventureModePredicate(BlockPredicate[] predicates, boolean showInTooltip) {
 
@@ -42,4 +43,11 @@ public record AdventureModePredicate(BlockPredicate[] predicates, boolean showIn
         }
     };
 
+    public AdventureModePredicate rewrite(final Int2IntFunction blockIdRewriter) {
+        final BlockPredicate[] predicates = new BlockPredicate[this.predicates.length];
+        for (int i = 0; i < predicates.length; i++) {
+            predicates[i] = this.predicates[i].rewrite(blockIdRewriter);
+        }
+        return new AdventureModePredicate(predicates, showInTooltip);
+    }
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/ArmorTrim.java

@@ -25,6 +25,7 @@ package com.viaversion.viaversion.api.minecraft.item.data;
 import com.viaversion.viaversion.api.minecraft.Holder;
 import com.viaversion.viaversion.api.type.Type;
 import io.netty.buffer.ByteBuf;
+import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 
 public record ArmorTrim(Holder<ArmorTrimMaterial> material, Holder<ArmorTrimPattern> pattern, boolean showInTooltip) {
 
@@ -45,4 +46,16 @@ public record ArmorTrim(Holder<ArmorTrimMaterial> material, Holder<ArmorTrimPatt
         }
     };
 
+    public ArmorTrim rewrite(final Int2IntFunction idRewriteFunction) {
+        Holder<ArmorTrimMaterial> material = this.material;
+        if (material.isDirect()) {
+            material = Holder.of(material.value().rewrite(idRewriteFunction));
+        }
+
+        Holder<ArmorTrimPattern> pattern = this.pattern;
+        if (pattern.isDirect()) {
+            pattern = Holder.of(pattern.value().rewrite(idRewriteFunction));
+        }
+        return new ArmorTrim(material, pattern, showInTooltip);
+    }
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/ArmorTrimMaterial.java

@@ -26,6 +26,7 @@ import com.viaversion.nbt.tag.Tag;
 import com.viaversion.viaversion.api.type.Types;
 import com.viaversion.viaversion.api.type.types.misc.HolderType;
 import io.netty.buffer.ByteBuf;
+import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
 import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
 
@@ -67,4 +68,7 @@ public record ArmorTrimMaterial(String assetName, int itemId, float itemModelInd
         }
     };
 
+    public ArmorTrimMaterial rewrite(final Int2IntFunction idRewriteFunction) {
+        return new ArmorTrimMaterial(assetName, idRewriteFunction.applyAsInt(itemId), itemModelIndex, overrideArmorMaterials, description);
+    }
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/ArmorTrimPattern.java

@@ -26,6 +26,7 @@ import com.viaversion.nbt.tag.Tag;
 import com.viaversion.viaversion.api.type.Types;
 import com.viaversion.viaversion.api.type.types.misc.HolderType;
 import io.netty.buffer.ByteBuf;
+import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 
 public record ArmorTrimPattern(String assetName, int itemId, Tag description, boolean decal) {
 
@@ -48,4 +49,7 @@ public record ArmorTrimPattern(String assetName, int itemId, Tag description, bo
         }
     };
 
+    public ArmorTrimPattern rewrite(final Int2IntFunction idRewriteFunction) {
+        return new ArmorTrimPattern(assetName, idRewriteFunction.applyAsInt(itemId), description, decal);
+    }
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/AttributeModifiers1_20_5.java

@@ -0,0 +1,90 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2024 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.item.data;
+
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.api.type.types.ArrayType;
+import io.netty.buffer.ByteBuf;
+import java.util.UUID;
+
+public record AttributeModifiers1_20_5(AttributeModifier[] modifiers, boolean showInTooltip) {
+
+    public static final Type<AttributeModifiers1_20_5> TYPE = new Type<>(AttributeModifiers1_20_5.class) {
+        @Override
+        public AttributeModifiers1_20_5 read(final ByteBuf buffer) {
+            final AttributeModifier[] modifiers = AttributeModifier.ARRAY_TYPE.read(buffer);
+            final boolean showInTooltip = buffer.readBoolean();
+            return new AttributeModifiers1_20_5(modifiers, showInTooltip);
+        }
+
+        @Override
+        public void write(final ByteBuf buffer, final AttributeModifiers1_20_5 value) {
+            AttributeModifier.ARRAY_TYPE.write(buffer, value.modifiers());
+            buffer.writeBoolean(value.showInTooltip());
+        }
+    };
+
+    public record AttributeModifier(int attribute, ModifierData modifier, int slotType) {
+
+        public static final Type<AttributeModifier> TYPE = new Type<>(AttributeModifier.class) {
+            @Override
+            public AttributeModifier read(final ByteBuf buffer) {
+                final int attribute = Types.VAR_INT.readPrimitive(buffer);
+                final ModifierData modifier = ModifierData.TYPE.read(buffer);
+                final int slot = Types.VAR_INT.readPrimitive(buffer);
+                return new AttributeModifier(attribute, modifier, slot);
+            }
+
+            @Override
+            public void write(final ByteBuf buffer, final AttributeModifier value) {
+                Types.VAR_INT.writePrimitive(buffer, value.attribute);
+                ModifierData.TYPE.write(buffer, value.modifier);
+                Types.VAR_INT.writePrimitive(buffer, value.slotType);
+            }
+        };
+        public static final Type<AttributeModifier[]> ARRAY_TYPE = new ArrayType<>(TYPE);
+    }
+
+    public record ModifierData(UUID uuid, String name, double amount, int operation) {
+
+        public static final Type<ModifierData> TYPE = new Type<>(ModifierData.class) {
+            @Override
+            public ModifierData read(final ByteBuf buffer) {
+                final UUID uuid = Types.UUID.read(buffer);
+                final String name = Types.STRING.read(buffer);
+                final double amount = buffer.readDouble();
+                final int operation = Types.VAR_INT.readPrimitive(buffer);
+                return new ModifierData(uuid, name, amount, operation);
+            }
+
+            @Override
+            public void write(final ByteBuf buffer, final ModifierData value) {
+                Types.UUID.write(buffer, value.uuid);
+                Types.STRING.write(buffer, value.name);
+                buffer.writeDouble(value.amount);
+                Types.VAR_INT.writePrimitive(buffer, value.operation);
+            }
+        };
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/AttributeModifiers1_21.java

@@ -0,0 +1,87 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2024 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.item.data;
+
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.api.type.types.ArrayType;
+import io.netty.buffer.ByteBuf;
+
+public record AttributeModifiers1_21(AttributeModifier[] modifiers, boolean showInTooltip) {
+
+    public static final Type<AttributeModifiers1_21> TYPE = new Type<>(AttributeModifiers1_21.class) {
+        @Override
+        public AttributeModifiers1_21 read(final ByteBuf buffer) {
+            final AttributeModifier[] modifiers = AttributeModifier.ARRAY_TYPE.read(buffer);
+            final boolean showInTooltip = buffer.readBoolean();
+            return new AttributeModifiers1_21(modifiers, showInTooltip);
+        }
+
+        @Override
+        public void write(final ByteBuf buffer, final AttributeModifiers1_21 value) {
+            AttributeModifier.ARRAY_TYPE.write(buffer, value.modifiers());
+            buffer.writeBoolean(value.showInTooltip());
+        }
+    };
+
+    public record AttributeModifier(int attribute, ModifierData modifier, int slotType) {
+
+        public static final Type<AttributeModifier> TYPE = new Type<>(AttributeModifier.class) {
+            @Override
+            public AttributeModifier read(final ByteBuf buffer) {
+                final int attribute = Types.VAR_INT.readPrimitive(buffer);
+                final ModifierData modifier = ModifierData.TYPE.read(buffer);
+                final int slot = Types.VAR_INT.readPrimitive(buffer);
+                return new AttributeModifier(attribute, modifier, slot);
+            }
+
+            @Override
+            public void write(final ByteBuf buffer, final AttributeModifier value) {
+                Types.VAR_INT.writePrimitive(buffer, value.attribute);
+                ModifierData.TYPE.write(buffer, value.modifier);
+                Types.VAR_INT.writePrimitive(buffer, value.slotType);
+            }
+        };
+        public static final Type<AttributeModifier[]> ARRAY_TYPE = new ArrayType<>(TYPE);
+    }
+
+    public record ModifierData(String id, double amount, int operation) {
+
+        public static final Type<ModifierData> TYPE = new Type<>(ModifierData.class) {
+            @Override
+            public ModifierData read(final ByteBuf buffer) {
+                final String id = Types.STRING.read(buffer);
+                final double amount = buffer.readDouble();
+                final int operation = Types.VAR_INT.readPrimitive(buffer);
+                return new ModifierData(id, amount, operation);
+            }
+
+            @Override
+            public void write(final ByteBuf buffer, final ModifierData value) {
+                Types.STRING.write(buffer, value.id);
+                buffer.writeDouble(value.amount);
+                Types.VAR_INT.writePrimitive(buffer, value.operation);
+            }
+        };
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/BlockPredicate.java

@@ -28,6 +28,7 @@ import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
 import com.viaversion.viaversion.api.type.types.ArrayType;
 import io.netty.buffer.ByteBuf;
+import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 public record BlockPredicate(@Nullable HolderSet holderSet, StatePropertyMatcher @Nullable [] propertyMatchers,
@@ -56,4 +57,12 @@ public record BlockPredicate(@Nullable HolderSet holderSet, StatePropertyMatcher
     };
     public static final Type<BlockPredicate[]> ARRAY_TYPE = new ArrayType<>(TYPE);
 
+    public BlockPredicate rewrite(final Int2IntFunction blockIdRewriter) {
+        if (holderSet == null || holderSet.hasTagKey()) {
+            return this;
+        }
+
+        final HolderSet updatedHolders = holderSet.rewrite(blockIdRewriter);
+        return new BlockPredicate(updatedHolders, propertyMatchers, tag);
+    }
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/ChatType.java

@@ -0,0 +1,68 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2024 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.item.data;
+
+import com.viaversion.nbt.tag.Tag;
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.api.type.types.misc.HolderType;
+import io.netty.buffer.ByteBuf;
+
+public record ChatType(ChatTypeDecoration chatDecoration, ChatTypeDecoration narrationDecoration) {
+
+    public static final HolderType<ChatType> TYPE = new HolderType<>() {
+        @Override
+        public ChatType readDirect(final ByteBuf buffer) {
+            final ChatTypeDecoration chatDecoration = ChatTypeDecoration.TYPE.read(buffer);
+            final ChatTypeDecoration narrationDecoration = ChatTypeDecoration.TYPE.read(buffer);
+            return new ChatType(chatDecoration, narrationDecoration);
+        }
+
+        @Override
+        public void writeDirect(final ByteBuf buffer, final ChatType value) {
+            ChatTypeDecoration.TYPE.write(buffer, value.chatDecoration());
+            ChatTypeDecoration.TYPE.write(buffer, value.narrationDecoration());
+        }
+    };
+
+    public record ChatTypeDecoration(String translationKey, int[] parameters, Tag style) {
+
+        public static final Type<ChatTypeDecoration> TYPE = new Type<>(ChatTypeDecoration.class) {
+
+            @Override
+            public ChatTypeDecoration read(final ByteBuf buffer) {
+                final String translationKey = Types.STRING.read(buffer);
+                final int[] parameters = Types.INT_ARRAY_PRIMITIVE.read(buffer);
+                final Tag style = Types.TAG.read(buffer);
+                return new ChatTypeDecoration(translationKey, parameters, style);
+            }
+
+            @Override
+            public void write(final ByteBuf buffer, final ChatTypeDecoration value) {
+                Types.STRING.write(buffer, value.translationKey());
+                Types.INT_ARRAY_PRIMITIVE.write(buffer, value.parameters());
+                Types.TAG.write(buffer, value.style());
+            }
+        };
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/FoodProperties.java

@@ -22,14 +22,16 @@
  */
 package com.viaversion.viaversion.api.minecraft.item.data;
 
+import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.api.type.types.version.Types1_21;
 import io.netty.buffer.ByteBuf;
 
 public record FoodProperties(int nutrition, float saturationModifier, boolean canAlwaysEat, float eatSeconds,
-                             FoodEffect[] possibleEffects) {
+                             Item usingConvertsTo, FoodEffect[] possibleEffects) {
 
-    public static final Type<FoodProperties> TYPE = new Type<>(FoodProperties.class) {
+    public static final Type<FoodProperties> TYPE1_20_5 = new Type<>(FoodProperties.class) {
         @Override
         public FoodProperties read(final ByteBuf buffer) {
             final int nutrition = Types.VAR_INT.readPrimitive(buffer);
@@ -37,7 +39,7 @@ public record FoodProperties(int nutrition, float saturationModifier, boolean ca
             final boolean canAlwaysEat = buffer.readBoolean();
             final float eatSeconds = buffer.readFloat();
             final FoodEffect[] possibleEffects = FoodEffect.ARRAY_TYPE.read(buffer);
-            return new FoodProperties(nutrition, saturationModifier, canAlwaysEat, eatSeconds, possibleEffects);
+            return new FoodProperties(nutrition, saturationModifier, canAlwaysEat, eatSeconds, null, possibleEffects);
         }
 
         @Override
@@ -49,5 +51,26 @@ public record FoodProperties(int nutrition, float saturationModifier, boolean ca
             FoodEffect.ARRAY_TYPE.write(buffer, value.possibleEffects);
         }
     };
+    public static final Type<FoodProperties> TYPE1_21 = new Type<FoodProperties>(FoodProperties.class) {
+        @Override
+        public FoodProperties read(final ByteBuf buffer) {
+            final int nutrition = Types.VAR_INT.readPrimitive(buffer);
+            final float saturationModifier = buffer.readFloat();
+            final boolean canAlwaysEat = buffer.readBoolean();
+            final float eatSeconds = buffer.readFloat();
+            final Item usingConvertsTo = Types1_21.OPTIONAL_ITEM.read(buffer);
+            final FoodEffect[] possibleEffects = FoodEffect.ARRAY_TYPE.read(buffer);
+            return new FoodProperties(nutrition, saturationModifier, canAlwaysEat, eatSeconds, usingConvertsTo, possibleEffects);
+        }
 
+        @Override
+        public void write(final ByteBuf buffer, final FoodProperties value) {
+            Types.VAR_INT.writePrimitive(buffer, value.nutrition);
+            buffer.writeFloat(value.saturationModifier);
+            buffer.writeBoolean(value.canAlwaysEat);
+            buffer.writeFloat(value.eatSeconds);
+            Types1_21.OPTIONAL_ITEM.write(buffer, value.usingConvertsTo);
+            FoodEffect.ARRAY_TYPE.write(buffer, value.possibleEffects);
+        }
+    };
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/JukeboxPlayable.java

@@ -0,0 +1,81 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2024 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.item.data;
+
+import com.viaversion.nbt.tag.Tag;
+import com.viaversion.viaversion.api.minecraft.Holder;
+import com.viaversion.viaversion.api.minecraft.SoundEvent;
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.api.type.types.misc.HolderType;
+import com.viaversion.viaversion.util.Either;
+import io.netty.buffer.ByteBuf;
+
+public record JukeboxPlayable(Either<Holder<JukeboxSong>, String> song, boolean showInTooltip) {
+
+    public JukeboxPlayable(final Holder<JukeboxSong> song, final boolean showInTooltip) {
+        this(Either.left(song), showInTooltip);
+    }
+
+    public JukeboxPlayable(final String resourceKey, final boolean showInTooltip) {
+        this(Either.right(resourceKey), showInTooltip);
+    }
+
+    public static final Type<JukeboxPlayable> TYPE = new Type<>(JukeboxPlayable.class) {
+        @Override
+        public JukeboxPlayable read(final ByteBuf buffer) {
+            final Either<Holder<JukeboxSong>, String> position = Type.readEither(buffer, JukeboxSong.TYPE, Types.STRING);
+            final boolean showInTooltip = buffer.readBoolean();
+            return new JukeboxPlayable(position, showInTooltip);
+        }
+
+        @Override
+        public void write(final ByteBuf buffer, final JukeboxPlayable value) {
+            Type.writeEither(buffer, value.song, JukeboxSong.TYPE, Types.STRING);
+            buffer.writeBoolean(value.showInTooltip);
+        }
+    };
+
+    public record JukeboxSong(Holder<SoundEvent> soundEvent, Tag description,
+                              float lengthInSeconds, int comparatorOutput) {
+
+        public static final HolderType<JukeboxSong> TYPE = new HolderType<>() {
+            @Override
+            public JukeboxSong readDirect(final ByteBuf buffer) {
+                final Holder<SoundEvent> soundEvent = Types.SOUND_EVENT.read(buffer);
+                final Tag description = Types.TAG.read(buffer);
+                final float lengthInSeconds = buffer.readFloat();
+                final int useDuration = Types.VAR_INT.readPrimitive(buffer);
+                return new JukeboxSong(soundEvent, description, lengthInSeconds, useDuration);
+            }
+
+            @Override
+            public void writeDirect(final ByteBuf buffer, final JukeboxSong value) {
+                Types.SOUND_EVENT.write(buffer, value.soundEvent);
+                Types.TAG.write(buffer, value.description);
+                buffer.writeFloat(value.lengthInSeconds);
+                Types.VAR_INT.writePrimitive(buffer, value.comparatorOutput);
+            }
+        };
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/PotDecorations.java

@@ -25,6 +25,7 @@ package com.viaversion.viaversion.api.minecraft.item.data;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
 import io.netty.buffer.ByteBuf;
+import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 
 public final class PotDecorations {
 
@@ -73,4 +74,12 @@ public final class PotDecorations {
     private int item(final int index) {
         return index < 0 || index >= itemIds.length ? -1 : itemIds[index];
     }
+
+    public PotDecorations rewrite(final Int2IntFunction idRewriteFunction) {
+        final int[] newItems = new int[itemIds.length];
+        for (int i = 0; i < itemIds.length; i++) {
+            newItems[i] = idRewriteFunction.applyAsInt(itemIds[i]);
+        }
+        return new PotDecorations(newItems);
+    }
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/StatePropertyMatcher.java

@@ -31,7 +31,6 @@ import org.checkerframework.checker.nullness.qual.Nullable;
 
 public record StatePropertyMatcher(String name, Either<String, RangedMatcher> matcher) {
 
-    // TODO Abstract Either reading
     public static final Type<StatePropertyMatcher> TYPE = new Type<>(StatePropertyMatcher.class) {
         @Override
         public StatePropertyMatcher read(final ByteBuf buffer) {

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/ToolProperties.java

@@ -25,6 +25,7 @@ package com.viaversion.viaversion.api.minecraft.item.data;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
 import io.netty.buffer.ByteBuf;
+import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 
 public record ToolProperties(ToolRule[] rules, float defaultMiningSpeed, int damagePerBlock) {
 
@@ -45,4 +46,11 @@ public record ToolProperties(ToolRule[] rules, float defaultMiningSpeed, int dam
         }
     };
 
+    public ToolProperties rewrite(final Int2IntFunction blockIdRewriter) {
+        final ToolRule[] rules = new ToolRule[this.rules.length];
+        for (int i = 0; i < rules.length; i++) {
+            rules[i] = this.rules[i].rewrite(blockIdRewriter);
+        }
+        return new ToolProperties(rules, defaultMiningSpeed, damagePerBlock);
+    }
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/ToolRule.java

@@ -27,6 +27,7 @@ import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
 import com.viaversion.viaversion.api.type.types.ArrayType;
 import io.netty.buffer.ByteBuf;
+import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 public record ToolRule(HolderSet blocks, @Nullable Float speed, @Nullable Boolean correctForDrops) {
@@ -49,4 +50,7 @@ public record ToolRule(HolderSet blocks, @Nullable Float speed, @Nullable Boolea
     };
     public static final Type<ToolRule[]> ARRAY_TYPE = new ArrayType<>(TYPE);
 
+    public ToolRule rewrite(final Int2IntFunction blockIdRewriter) {
+        return blocks.hasIds() ? new ToolRule(blocks.rewrite(blockIdRewriter), speed, correctForDrops) : this;
+    }
 }

api/src/main/java/com/viaversion/viaversion/api/protocol/Protocol.java

@@ -33,6 +33,7 @@ import com.viaversion.viaversion.api.protocol.packet.ServerboundPacketType;
 import com.viaversion.viaversion.api.protocol.packet.State;
 import com.viaversion.viaversion.api.protocol.packet.provider.PacketTypesProvider;
 import com.viaversion.viaversion.api.protocol.remapper.PacketHandler;
+import com.viaversion.viaversion.api.rewriter.ComponentRewriter;
 import com.viaversion.viaversion.api.rewriter.EntityRewriter;
 import com.viaversion.viaversion.api.rewriter.ItemRewriter;
 import com.viaversion.viaversion.api.rewriter.TagRewriter;
@@ -382,6 +383,10 @@ public interface Protocol<CU extends ClientboundPacketType, CM extends Clientbou
         return null;
     }
 
+    default @Nullable ComponentRewriter getComponentRewriter() {
+        return null;
+    }
+
     /**
      * Returns whether this protocol is a base protocol.
      *

api/src/main/java/com/viaversion/viaversion/api/protocol/version/ProtocolVersion.java

@@ -84,6 +84,7 @@ public class ProtocolVersion implements Comparable<ProtocolVersion> {
     public static final ProtocolVersion v1_20_2 = register(764, "1.20.2");
     public static final ProtocolVersion v1_20_3 = register(765, "1.20.3-1.20.4", new SubVersionRange("1.20", 3, 4));
     public static final ProtocolVersion v1_20_5 = register(766, "1.20.5-1.20.6", new SubVersionRange("1.20", 5, 6));
+    public static final ProtocolVersion v1_21 = register(767, "1.21");
     public static final ProtocolVersion unknown = new ProtocolVersion(VersionType.SPECIAL, -1, -1, "UNKNOWN", null);
 
     public static ProtocolVersion register(int version, String name) {

api/src/main/java/com/viaversion/viaversion/api/protocol/version/ProtocolVersionRange.java

@@ -104,7 +104,10 @@ public class ProtocolVersionRange {
      */
     public boolean contains(final ProtocolVersion version) {
         if (this.ranges == null) return true;
-        return this.ranges.stream().anyMatch(range -> range.contains(version));
+        for (Range<ProtocolVersion> range : this.ranges) {
+            if (range.contains(version)) return true;
+        }
+        return false;
     }
 
     @Override

api/src/main/java/com/viaversion/viaversion/api/rewriter/ComponentRewriter.java

@@ -20,26 +20,16 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-package com.viaversion.viaversion.api.minecraft.item.data;
+package com.viaversion.viaversion.api.rewriter;
 
-import com.viaversion.viaversion.api.type.Type;
-import io.netty.buffer.ByteBuf;
+import com.google.gson.JsonElement;
+import com.viaversion.nbt.tag.Tag;
+import com.viaversion.viaversion.api.connection.UserConnection;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
-public record AttributeModifiers(AttributeModifier[] modifiers, boolean showInTooltip) {
+public interface ComponentRewriter {
 
-    public static final Type<AttributeModifiers> TYPE = new Type<>(AttributeModifiers.class) {
-        @Override
-        public AttributeModifiers read(final ByteBuf buffer) {
-            final AttributeModifier[] modifiers = AttributeModifier.ARRAY_TYPE.read(buffer);
-            final boolean showInTooltip = buffer.readBoolean();
-            return new AttributeModifiers(modifiers, showInTooltip);
-        }
-
-        @Override
-        public void write(final ByteBuf buffer, final AttributeModifiers value) {
-            AttributeModifier.ARRAY_TYPE.write(buffer, value.modifiers());
-            buffer.writeBoolean(value.showInTooltip());
-        }
-    };
+    void processTag(UserConnection connection, @Nullable Tag tag);
 
+    void processText(UserConnection connection, @Nullable JsonElement element);
 }

api/src/main/java/com/viaversion/viaversion/api/type/Type.java

@@ -22,6 +22,9 @@
  */
 package com.viaversion.viaversion.api.type;
 
+import com.viaversion.viaversion.util.Either;
+import io.netty.buffer.ByteBuf;
+
 /**
  * Type for buffer reading and writing.
  *
@@ -75,4 +78,22 @@ public abstract class Type<T> implements ByteBufReader<T>, ByteBufWriter<T> {
     public String toString() {
         return getTypeName();
     }
+
+    public static <X, Y> Either<X, Y> readEither(final ByteBuf buf, final Type<X> leftType, final Type<Y> rightType) {
+        if (buf.readBoolean()) {
+            return Either.left(leftType.read(buf));
+        } else {
+            return Either.right(rightType.read(buf));
+        }
+    }
+
+    public static <X, Y> void writeEither(final ByteBuf buf, final Either<X, Y> value, final Type<X> leftType, final Type<Y> rightType) {
+        if (value.isLeft()) {
+            buf.writeBoolean(true);
+            leftType.write(buf, value.left());
+        } else {
+            buf.writeBoolean(false);
+            rightType.write(buf, value.right());
+        }
+    }
 }

api/src/main/java/com/viaversion/viaversion/api/type/types/item/ItemType1_13.java

@@ -44,16 +44,13 @@ public class ItemType1_13 extends Type<Item> {
             item.setIdentifier(id);
             item.setAmount(buffer.readByte());
             item.setTag(Types.NAMED_COMPOUND_TAG.read(buffer));
-            if (item.isEmpty()) {
-                return null;
-            }
             return item;
         }
     }
 
     @Override
     public void write(ByteBuf buffer, @Nullable Item object) {
-        if (object == null || object.isEmpty()) {
+        if (object == null) {
             buffer.writeShort(-1);
         } else {
             buffer.writeShort(object.identifier());

api/src/main/java/com/viaversion/viaversion/api/type/types/item/ItemType1_13_2.java

@@ -44,16 +44,13 @@ public class ItemType1_13_2 extends Type<Item> {
             item.setIdentifier(Types.VAR_INT.readPrimitive(buffer));
             item.setAmount(buffer.readByte());
             item.setTag(Types.NAMED_COMPOUND_TAG.read(buffer));
-            if (item.isEmpty()) {
-                return null;
-            }
             return item;
         }
     }
 
     @Override
     public void write(ByteBuf buffer, @Nullable Item object) {
-        if (object == null || object.isEmpty()) {
+        if (object == null) {
             buffer.writeBoolean(false);
         } else {
             buffer.writeBoolean(true);

api/src/main/java/com/viaversion/viaversion/api/type/types/item/ItemType1_20_2.java

@@ -45,15 +45,12 @@ public class ItemType1_20_2 extends Type<Item> {
         item.setIdentifier(Types.VAR_INT.readPrimitive(buffer));
         item.setAmount(buffer.readByte());
         item.setTag(Types.COMPOUND_TAG.read(buffer));
-        if (item.isEmpty()) {
-            return null;
-        }
         return item;
     }
 
     @Override
     public void write(final ByteBuf buffer, @Nullable final Item object) {
-        if (object == null || object.isEmpty()) {
+        if (object == null) {
             buffer.writeBoolean(false);
         } else {
             buffer.writeBoolean(true);

api/src/main/java/com/viaversion/viaversion/api/type/types/item/ItemType1_20_5.java

@@ -28,6 +28,7 @@ import com.viaversion.viaversion.api.minecraft.data.StructuredDataContainer;
 import com.viaversion.viaversion.api.minecraft.data.StructuredDataKey;
 import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.minecraft.item.StructuredItem;
+import com.viaversion.viaversion.api.type.OptionalType;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
 import io.netty.buffer.ByteBuf;
@@ -114,4 +115,11 @@ public class ItemType1_20_5 extends Type<Item> {
             }
         }
     }
+
+    public final class OptionalItemType extends OptionalType<Item> {
+
+        public OptionalItemType() {
+            super(ItemType1_20_5.this);
+        }
+    }
 }

api/src/main/java/com/viaversion/viaversion/api/type/types/item/StructuredDataType.java

@@ -83,6 +83,7 @@ public class StructuredDataType extends Type<StructuredData<?>> {
         public DataFiller add(final StructuredDataKey<?> key) {
             final int id = mappings.mappedId(key.identifier());
             Preconditions.checkArgument(id != -1, "No mapped id found for %s", key.identifier());
+            Preconditions.checkArgument(types[id] == null, "Data component serializer already exists for id %s", id);
             types[id] = key;
             return this;
         }

api/src/main/java/com/viaversion/viaversion/api/type/types/misc/ParticleType.java

@@ -71,8 +71,6 @@ public class ParticleType extends DynamicType<Particle> {
         };
         public static final DataReader<Particle> ITEM1_13 = itemHandler(Types.ITEM1_13);
         public static final DataReader<Particle> ITEM1_13_2 = itemHandler(Types.ITEM1_13_2);
-        public static final DataReader<Particle> ITEM1_20_2 = itemHandler(Types.ITEM1_20_2);
-        public static final DataReader<Particle> ITEM1_20_5 = itemHandler(Types1_20_5.ITEM);
         public static final DataReader<Particle> DUST = (buf, particle) -> {
             particle.add(Types.FLOAT, Types.FLOAT.readPrimitive(buf)); // Red 0-1
             particle.add(Types.FLOAT, Types.FLOAT.readPrimitive(buf)); // Green 0-1
@@ -139,5 +137,9 @@ public class ParticleType extends DynamicType<Particle> {
             particle.add(Types.VAR_INT, Types.VAR_INT.readPrimitive(buf)); // Delay
         };
         public static final DataReader<Particle> COLOR = (buf, particle) -> particle.add(Types.INT, buf.readInt());
+
+        public static DataReader<Particle> item(Type<Item> item) {
+            return (buf, particle) -> particle.add(item, item.read(buf));
+        }
     }
 }

api/src/main/java/com/viaversion/viaversion/api/type/types/version/Types1_21.java

@@ -0,0 +1,56 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2024 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.type.types.version;
+
+import com.viaversion.viaversion.api.minecraft.Particle;
+import com.viaversion.viaversion.api.minecraft.data.StructuredData;
+import com.viaversion.viaversion.api.minecraft.entitydata.EntityData;
+import com.viaversion.viaversion.api.minecraft.entitydata.types.EntityDataTypes1_21;
+import com.viaversion.viaversion.api.minecraft.item.Item;
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.types.ArrayType;
+import com.viaversion.viaversion.api.type.types.entitydata.EntityDataListType;
+import com.viaversion.viaversion.api.type.types.entitydata.EntityDataType;
+import com.viaversion.viaversion.api.type.types.item.ItemCostType1_20_5;
+import com.viaversion.viaversion.api.type.types.item.ItemType1_20_5;
+import com.viaversion.viaversion.api.type.types.item.StructuredDataType;
+import com.viaversion.viaversion.api.type.types.misc.ParticleType;
+import java.util.List;
+
+// Most of these are only safe to use after protocol loading
+public final class Types1_21 {
+
+    public static final StructuredDataType STRUCTURED_DATA = new StructuredDataType();
+    public static final Type<StructuredData<?>[]> STRUCTURED_DATA_ARRAY = new ArrayType<>(STRUCTURED_DATA);
+    public static final ItemType1_20_5 ITEM = new ItemType1_20_5(STRUCTURED_DATA);
+    public static final Type<Item> OPTIONAL_ITEM = ITEM.new OptionalItemType(); // Optional as in boolean prefixed, not via the amount
+    public static final Type<Item[]> ITEM_ARRAY = new ArrayType<>(ITEM);
+    public static final Type<Item> ITEM_COST = new ItemCostType1_20_5(STRUCTURED_DATA_ARRAY);
+    public static final Type<Item> OPTIONAL_ITEM_COST = new ItemCostType1_20_5.OptionalItemCostType(ITEM_COST);
+
+    public static final ParticleType PARTICLE = new ParticleType();
+    public static final ArrayType<Particle> PARTICLES = new ArrayType<>(PARTICLE);
+    public static final EntityDataTypes1_21 ENTITY_DATA_TYPES = new EntityDataTypes1_21(PARTICLE, PARTICLES);
+    public static final Type<EntityData> ENTITY_DATA = new EntityDataType(ENTITY_DATA_TYPES);
+    public static final Type<List<EntityData>> ENTITY_DATA_LIST = new EntityDataListType(ENTITY_DATA);
+}

api/src/main/java/com/viaversion/viaversion/util/Key.java

@@ -47,7 +47,7 @@ public final class Key {
     }
 
     public static boolean equals(final String firstIdentifier, final String secondIdentifier) {
-        return stripNamespace(firstIdentifier).equals(stripNamespace(secondIdentifier));
+        return stripMinecraftNamespace(firstIdentifier).equals(stripMinecraftNamespace(secondIdentifier));
     }
 
     public static String namespaced(final String identifier) {

bukkit/src/main/java/com/viaversion/viaversion/bukkit/listeners/v1_20_5to1_21/PlayerChangeItemListener.java

@@ -0,0 +1,111 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2024 ViaVersion and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.viaversion.viaversion.bukkit.listeners.v1_20_5to1_21;
+
+import com.viaversion.viaversion.ViaVersionPlugin;
+import com.viaversion.viaversion.api.Via;
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.bukkit.listeners.ViaBukkitListener;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.Protocol1_20_5To1_21;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.storage.EfficiencyAttributeStorage;
+import io.papermc.paper.event.player.PlayerInventorySlotChangeEvent;
+import org.bukkit.NamespacedKey;
+import org.bukkit.enchantments.Enchantment;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.player.PlayerItemHeldEvent;
+import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.PlayerInventory;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+/**
+ * For some reason, mining efficiency is not calculated by the client anymore, but by the server,
+ * then sending the current value to the client every time the item changes. This roughly emulates that behavior.
+ */
+public final class PlayerChangeItemListener extends ViaBukkitListener {
+
+    private final Enchantment efficiency = Enchantment.getByKey(NamespacedKey.minecraft("efficiency"));
+    private final Enchantment aquaAffinity = Enchantment.getByKey(NamespacedKey.minecraft("aqua_affinity"));
+    private final Enchantment depthStrider = Enchantment.getByKey(NamespacedKey.minecraft("depth_strider"));
+    private final Enchantment soulSpeed = Enchantment.getByKey(NamespacedKey.minecraft("soul_speed"));
+    private final Enchantment swiftSneak = Enchantment.getByKey(NamespacedKey.minecraft("swift_sneak"));
+
+    public PlayerChangeItemListener(final ViaVersionPlugin plugin) {
+        super(plugin, Protocol1_20_5To1_21.class);
+    }
+
+    @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
+    public void onPlayerInventorySlotChangedEvent(final PlayerInventorySlotChangeEvent event) {
+        final Player player = event.getPlayer();
+        final ItemStack item = event.getNewItemStack();
+        final PlayerInventory inventory = player.getInventory();
+        final int slot = event.getSlot();
+        if (slot == inventory.getHeldItemSlot()) {
+            sendAttributeUpdate(player, item, Slot.HAND);
+        } else if (slot == 36) {
+            sendAttributeUpdate(player, item, Slot.BOOTS);
+        } else if (slot == 37) {
+            sendAttributeUpdate(player, item, Slot.LEGGINGS);
+        } else if (slot == 39) {
+            sendAttributeUpdate(player, item, Slot.HELMET);
+        }
+    }
+
+    @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
+    public void onPlayerItemHeld(final PlayerItemHeldEvent event) {
+        final Player player = event.getPlayer();
+        final ItemStack item = player.getInventory().getItem(event.getNewSlot());
+        sendAttributeUpdate(player, item, Slot.HAND);
+    }
+
+    private void sendAttributeUpdate(final Player player, @Nullable final ItemStack item, final Slot slot) {
+        final UserConnection connection = Via.getAPI().getConnection(player.getUniqueId());
+        if (connection == null || !isOnPipe(player)) {
+            return;
+        }
+
+        final EfficiencyAttributeStorage storage = connection.get(EfficiencyAttributeStorage.class);
+        if (storage == null) {
+            return;
+        }
+
+        final EfficiencyAttributeStorage.ActiveEnchants activeEnchants = storage.activeEnchants();
+        int efficiencyLevel = activeEnchants.efficiency().level();
+        int aquaAffinityLevel = activeEnchants.aquaAffinity().level();
+        int soulSpeedLevel = activeEnchants.soulSpeed().level();
+        int swiftSneakLevel = activeEnchants.swiftSneak().level();
+        int depthStriderLevel = activeEnchants.depthStrider().level();
+        switch (slot) {
+            case HAND -> efficiencyLevel = item != null ? item.getEnchantmentLevel(efficiency) : 0;
+            case HELMET -> aquaAffinityLevel = item != null ? item.getEnchantmentLevel(aquaAffinity) : 0;
+            case LEGGINGS -> swiftSneakLevel = item != null && swiftSneak != null ? item.getEnchantmentLevel(swiftSneak) : 0;
+            case BOOTS -> {
+                depthStriderLevel = item != null && depthStrider != null ? item.getEnchantmentLevel(depthStrider) : 0;
+                // TODO This needs continuous ticking for the supporting block as a conditional effect
+                //  and is even more prone to desync from high ping than the other attributes
+                //soulSpeedLevel = item != null && soulSpeed != null ? item.getEnchantmentLevel(soulSpeed) : 0;
+            }
+        }
+        storage.setEnchants(player.getEntityId(), connection, efficiencyLevel, soulSpeedLevel, swiftSneakLevel, aquaAffinityLevel, depthStriderLevel);
+    }
+
+    private enum Slot {
+        HAND, BOOTS, LEGGINGS, HELMET
+    }
+}

bukkit/src/main/java/com/viaversion/viaversion/bukkit/platform/BukkitViaLoader.java

@@ -33,6 +33,7 @@ import com.viaversion.viaversion.bukkit.listeners.protocol1_9to1_8.BlockListener
 import com.viaversion.viaversion.bukkit.listeners.protocol1_9to1_8.DeathListener;
 import com.viaversion.viaversion.bukkit.listeners.protocol1_9to1_8.HandItemCache;
 import com.viaversion.viaversion.bukkit.listeners.protocol1_9to1_8.PaperPatch;
+import com.viaversion.viaversion.bukkit.listeners.v1_20_5to1_21.PlayerChangeItemListener;
 import com.viaversion.viaversion.bukkit.providers.BukkitAckSequenceProvider;
 import com.viaversion.viaversion.bukkit.providers.BukkitBlockConnectionProvider;
 import com.viaversion.viaversion.bukkit.providers.BukkitInventoryQuickMoveProvider;
@@ -176,6 +177,9 @@ public class BukkitViaLoader implements ViaPlatformLoader {
             Via.getManager().getProviders().use(AckSequenceProvider.class, new BukkitAckSequenceProvider(plugin));
             new BlockBreakListener(plugin).register();
         }
+        if (serverProtocolVersion.olderThan(ProtocolVersion.v1_21) && PaperViaInjector.hasClass("io.papermc.paper.event.player.PlayerInventorySlotChangeEvent")) {
+            new PlayerChangeItemListener(plugin).register();
+        }
     }
 
     private boolean hasGetHandMethod() {

common/src/main/java/com/viaversion/viaversion/commands/ViaCommandHandler.java

@@ -30,6 +30,7 @@ import com.viaversion.viaversion.commands.defaultsubs.DumpSubCmd;
 import com.viaversion.viaversion.commands.defaultsubs.ListSubCmd;
 import com.viaversion.viaversion.commands.defaultsubs.PPSSubCmd;
 import com.viaversion.viaversion.commands.defaultsubs.ReloadSubCmd;
+import com.viaversion.viaversion.commands.defaultsubs.PlayerSubCmd;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -56,6 +57,11 @@ public abstract class ViaCommandHandler implements ViaVersionCommand {
         commandMap.put(command.name().toLowerCase(Locale.ROOT), command);
     }
 
+    @Override
+    public void removeSubCommand(final String name) {
+        commandMap.remove(name.toLowerCase(Locale.ROOT));
+    }
+
     @Override
     public boolean hasSubCommand(String name) {
         return commandMap.containsKey(name.toLowerCase(Locale.ROOT));
@@ -194,5 +200,6 @@ public abstract class ViaCommandHandler implements ViaVersionCommand {
         registerSubCommand(new DontBugMeSubCmd());
         registerSubCommand(new AutoTeamSubCmd());
         registerSubCommand(new ReloadSubCmd());
+        registerSubCommand(new PlayerSubCmd());
     }
 }

common/src/main/java/com/viaversion/viaversion/commands/defaultsubs/DisplayLeaksSubCmd.java

@@ -20,6 +20,9 @@ package com.viaversion.viaversion.commands.defaultsubs;
 import com.viaversion.viaversion.api.command.ViaCommandSender;
 import com.viaversion.viaversion.api.command.ViaSubCommand;
 import io.netty.util.ResourceLeakDetector;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
 
 public class DisplayLeaksSubCmd implements ViaSubCommand {
     @Override
@@ -33,13 +36,34 @@ public class DisplayLeaksSubCmd implements ViaSubCommand {
     }
 
     @Override
-    public boolean execute(ViaCommandSender sender, String[] args) {
-        if (ResourceLeakDetector.getLevel() != ResourceLeakDetector.Level.PARANOID)
-            ResourceLeakDetector.setLevel(ResourceLeakDetector.Level.PARANOID);
-        else
-            ResourceLeakDetector.setLevel(ResourceLeakDetector.Level.DISABLED);
+    public String usage() {
+        return "displayleaks <level>";
+    }
 
-        sendMessage(sender, "&6Leak detector is now %s", (ResourceLeakDetector.getLevel() == ResourceLeakDetector.Level.PARANOID ? "&aenabled" : "&cdisabled"));
+    @Override
+    public boolean execute(ViaCommandSender sender, String[] args) {
+        if (args.length == 1) {
+            try {
+                ResourceLeakDetector.Level level = ResourceLeakDetector.Level.valueOf(args[0]);
+                ResourceLeakDetector.setLevel(level);
+                sendMessage(sender, "&6Set leak detector level to &2" + level);
+            } catch (IllegalArgumentException e) {
+                sendMessage(sender, "&cInvalid level (" + Arrays.toString(ResourceLeakDetector.Level.values()) + ")");
+            }
+        } else {
+            sendMessage(sender, "&6Current leak detection level is &2" + ResourceLeakDetector.getLevel());
+        }
         return true;
     }
+
+    @Override
+    public List<String> onTabComplete(ViaCommandSender sender, String[] args) {
+        if (args.length == 1) {
+            return Arrays.stream(ResourceLeakDetector.Level.values())
+                .map(Enum::name)
+                .filter(it -> it.startsWith(args[0]))
+                .collect(Collectors.toList());
+        }
+        return ViaSubCommand.super.onTabComplete(sender, args);
+    }
 }

common/src/main/java/com/viaversion/viaversion/commands/defaultsubs/ListSubCmd.java

@@ -20,6 +20,7 @@ package com.viaversion.viaversion.commands.defaultsubs;
 import com.viaversion.viaversion.api.Via;
 import com.viaversion.viaversion.api.command.ViaCommandSender;
 import com.viaversion.viaversion.api.command.ViaSubCommand;
+import com.viaversion.viaversion.api.connection.UserConnection;
 import com.viaversion.viaversion.api.protocol.version.ProtocolVersion;
 import java.util.HashSet;
 import java.util.Map;
@@ -46,10 +47,9 @@ public class ListSubCmd implements ViaSubCommand {
     public boolean execute(ViaCommandSender sender, String[] args) {
         Map<ProtocolVersion, Set<String>> playerVersions = new TreeMap<>(ProtocolVersion::compareTo);
 
-        for (ViaCommandSender p : Via.getPlatform().getOnlinePlayers()) {
-            int playerVersion = Via.getAPI().getPlayerVersion(p.getUUID());
-            ProtocolVersion key = ProtocolVersion.getProtocol(playerVersion);
-            playerVersions.computeIfAbsent(key, s -> new HashSet<>()).add(p.getName());
+        for (UserConnection p : Via.getManager().getConnectionManager().getConnections()) {
+            ProtocolVersion version = p.getProtocolInfo().protocolVersion();
+            playerVersions.computeIfAbsent(version, s -> new HashSet<>()).add(p.getProtocolInfo().getUsername());
         }
 
         for (Map.Entry<ProtocolVersion, Set<String>> entry : playerVersions.entrySet()) {

common/src/main/java/com/viaversion/viaversion/commands/defaultsubs/PPSSubCmd.java

@@ -46,26 +46,25 @@ public class PPSSubCmd implements ViaSubCommand {
 
     @Override
     public boolean execute(ViaCommandSender sender, String[] args) {
-        Map<Integer, Set<String>> playerVersions = new HashMap<>();
+        Map<ProtocolVersion, Set<String>> playerVersions = new TreeMap<>(ProtocolVersion::compareTo);
         int totalPackets = 0;
         int clients = 0;
         long max = 0;
 
-        for (ViaCommandSender p : Via.getPlatform().getOnlinePlayers()) {
-            int playerVersion = Via.getAPI().getPlayerVersion(p.getUUID());
-            if (!playerVersions.containsKey(playerVersion))
+        for (UserConnection p : Via.getManager().getConnectionManager().getConnections()) {
+            ProtocolVersion playerVersion = p.getProtocolInfo().protocolVersion();
+            if (!playerVersions.containsKey(playerVersion)) {
                 playerVersions.put(playerVersion, new HashSet<>());
-            UserConnection uc = Via.getManager().getConnectionManager().getConnectedClient(p.getUUID());
-            if (uc != null && uc.getPacketTracker().getPacketsPerSecond() > -1) {
-                playerVersions.get(playerVersion).add(p.getName() + " (" + uc.getPacketTracker().getPacketsPerSecond() + " PPS)");
-                totalPackets += uc.getPacketTracker().getPacketsPerSecond();
-                if (uc.getPacketTracker().getPacketsPerSecond() > max) {
-                    max = uc.getPacketTracker().getPacketsPerSecond();
+            }
+            if (p.getPacketTracker().getPacketsPerSecond() > -1) {
+                playerVersions.get(playerVersion).add(p.getProtocolInfo().getUsername() + " (" + p.getPacketTracker().getPacketsPerSecond() + " PPS)");
+                totalPackets += p.getPacketTracker().getPacketsPerSecond();
+                if (p.getPacketTracker().getPacketsPerSecond() > max) {
+                    max = p.getPacketTracker().getPacketsPerSecond();
                 }
                 clients++;
             }
         }
-        Map<Integer, Set<String>> sorted = new TreeMap<>(playerVersions);
         sendMessage(sender, "&4Live Packets Per Second");
         if (clients > 1) {
             sendMessage(sender, "&cAverage: &f" + (totalPackets / clients));
@@ -74,9 +73,10 @@ public class PPSSubCmd implements ViaSubCommand {
         if (clients == 0) {
             sendMessage(sender, "&cNo clients to display.");
         }
-        for (Map.Entry<Integer, Set<String>> entry : sorted.entrySet())
-            sendMessage(sender, "&8[&6%s&8]: &b%s", ProtocolVersion.getProtocol(entry.getKey()).getName(), entry.getValue());
-        sorted.clear();
+        for (Map.Entry<ProtocolVersion, Set<String>> entry : playerVersions.entrySet()) {
+            sendMessage(sender, "&8[&6%s&8]: &b%s", entry.getKey().getName(), entry.getValue());
+        }
+        playerVersions.clear();
         return true;
     }
 }

common/src/main/java/com/viaversion/viaversion/commands/defaultsubs/PlayerSubCmd.java

@@ -0,0 +1,75 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2024 ViaVersion and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.viaversion.viaversion.commands.defaultsubs;
+
+import com.viaversion.viaversion.api.Via;
+import com.viaversion.viaversion.api.command.ViaCommandSender;
+import com.viaversion.viaversion.api.command.ViaSubCommand;
+import com.viaversion.viaversion.api.connection.ProtocolInfo;
+import com.viaversion.viaversion.api.connection.UserConnection;
+import java.util.ArrayList;
+import java.util.List;
+
+public class PlayerSubCmd implements ViaSubCommand {
+    @Override
+    public String name() {
+        return "player";
+    }
+
+    @Override
+    public String description() {
+        return "Shows connection information about one or all players.";
+    }
+
+    @Override
+    public String usage() {
+        return "player <name|*>";
+    }
+
+    @Override
+    public boolean execute(final ViaCommandSender sender, final String[] args) {
+        if (args.length == 0) {
+            return false;
+        }
+        for (final UserConnection connection : Via.getManager().getConnectionManager().getConnections()) {
+            final ProtocolInfo info = connection.getProtocolInfo();
+            if (args[0].equalsIgnoreCase(info.getUsername()) || args[0].equals("*")) {
+                sendMessage(sender, "&7[&6" + info.getUsername() + "&7] UUID: &2" + info.getUuid() + " &7Client-Protocol: &2" + info.protocolVersion().getName() + " &7Server-Protocol: &2" + info.serverProtocolVersion().getName());
+            }
+        }
+        return true;
+    }
+
+    @Override
+    public List<String> onTabComplete(final ViaCommandSender sender, final String[] args) {
+        if (args.length == 1) {
+            final String input = args[0].toLowerCase();
+
+            final List<String> matches = new ArrayList<>();
+            for (final UserConnection connection : Via.getManager().getConnectionManager().getConnections()) {
+                final String name = connection.getProtocolInfo().getUsername();
+                if (input.isEmpty() || name.toLowerCase().startsWith(input)) {
+                    matches.add(name);
+                }
+            }
+            matches.add("*");
+            return matches;
+        }
+        return ViaSubCommand.super.onTabComplete(sender, args);
+    }
+}

common/src/main/java/com/viaversion/viaversion/data/entity/DimensionDataImpl.java

@@ -48,6 +48,14 @@ public final class DimensionDataImpl implements DimensionData {
         this.minY = minY.asInt();
     }
 
+    public static DimensionData withDefaultsFor(final String key, final int id) {
+        return switch (key) {
+            case "overworld", "overworld_caves" -> new DimensionDataImpl(id, -64, 384);
+            case "the_nether", "the_end" -> new DimensionDataImpl(id, 0, 256);
+            default -> throw new IllegalArgumentException("Missing registry data for unknown dimension: " + key);
+        };
+    }
+
     @Override
     public int id() {
         return id;

common/src/main/java/com/viaversion/viaversion/protocol/ProtocolManagerImpl.java

@@ -41,6 +41,7 @@ import com.viaversion.viaversion.protocol.packet.VersionedPacketTransformerImpl;
 import com.viaversion.viaversion.protocols.base.BaseProtocol;
 import com.viaversion.viaversion.protocols.base.BaseProtocol1_16;
 import com.viaversion.viaversion.protocols.base.BaseProtocol1_7;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.Protocol1_20_5To1_21;
 import com.viaversion.viaversion.protocols.v1_10to1_11.Protocol1_10To1_11;
 import com.viaversion.viaversion.protocols.v1_11_1to1_12.Protocol1_11_1To1_12;
 import com.viaversion.viaversion.protocols.v1_11to1_11_1.Protocol1_11To1_11_1;
@@ -187,6 +188,8 @@ public class ProtocolManagerImpl implements ProtocolManager {
         registerProtocol(new Protocol1_20To1_20_2(), ProtocolVersion.v1_20_2, ProtocolVersion.v1_20);
         registerProtocol(new Protocol1_20_2To1_20_3(), ProtocolVersion.v1_20_3, ProtocolVersion.v1_20_2);
         registerProtocol(new Protocol1_20_3To1_20_5(), ProtocolVersion.v1_20_5, ProtocolVersion.v1_20_3);
+
+        registerProtocol(new Protocol1_20_5To1_21(), ProtocolVersion.v1_21, ProtocolVersion.v1_20_5);
     }
 
     @Override

common/src/main/java/com/viaversion/viaversion/protocols/v1_10to1_11/data/EntityMappings1_11.java

@@ -144,7 +144,6 @@ public class EntityMappings1_11 {
         if (hasEntityTag(item)) {
             toClient(item.tag().getCompoundTag("EntityTag"), backwards);
         }
-        if (item != null && item.amount() <= 0) item.setAmount(1);
     }
 
     public static void toServerItem(Item item) {

common/src/main/java/com/viaversion/viaversion/protocols/v1_10to1_11/rewriter/ItemPacketRewriter1_11.java

@@ -17,9 +17,10 @@
  */
 package com.viaversion.viaversion.protocols.v1_10to1_11.rewriter;
 
+import com.viaversion.nbt.tag.ByteTag;
+import com.viaversion.nbt.tag.CompoundTag;
 import com.viaversion.viaversion.api.connection.UserConnection;
 import com.viaversion.viaversion.api.minecraft.item.Item;
-import com.viaversion.viaversion.api.protocol.remapper.PacketHandlers;
 import com.viaversion.viaversion.api.type.Types;
 import com.viaversion.viaversion.protocols.v1_10to1_11.Protocol1_10To1_11;
 import com.viaversion.viaversion.protocols.v1_10to1_11.data.EntityMappings1_11;
@@ -38,45 +39,20 @@ public class ItemPacketRewriter1_11 extends ItemRewriter<ClientboundPackets1_9_3
         registerSetSlot(ClientboundPackets1_9_3.CONTAINER_SET_SLOT);
         registerSetContent(ClientboundPackets1_9_3.CONTAINER_SET_CONTENT);
         registerSetEquippedItem(ClientboundPackets1_9_3.SET_EQUIPPED_ITEM);
-
-        // Plugin message Packet -> Trading
-        protocol.registerClientbound(ClientboundPackets1_9_3.CUSTOM_PAYLOAD, new PacketHandlers() {
-            @Override
-            public void register() {
-                map(Types.STRING); // 0 - Channel
-
-                handlerSoftFail(wrapper -> {
-                    if (wrapper.get(Types.STRING, 0).equals("MC|TrList")) {
-                        wrapper.passthrough(Types.INT); // Passthrough Window ID
-
-                        int size = wrapper.passthrough(Types.UNSIGNED_BYTE);
-                        for (int i = 0; i < size; i++) {
-                            handleItemToClient(wrapper.user(), wrapper.passthrough(Types.ITEM1_8)); // Input Item
-                            handleItemToClient(wrapper.user(), wrapper.passthrough(Types.ITEM1_8)); // Output Item
-
-                            boolean secondItem = wrapper.passthrough(Types.BOOLEAN); // Has second item
-                            if (secondItem) {
-                                handleItemToClient(wrapper.user(), wrapper.passthrough(Types.ITEM1_8)); // Second Item
-                            }
-
-                            wrapper.passthrough(Types.BOOLEAN); // Trade disabled
-                            wrapper.passthrough(Types.INT); // Number of tools uses
-                            wrapper.passthrough(Types.INT); // Maximum number of trade uses
-                        }
-                    }
-                });
-            }
-        });
-
+        registerCustomPayloadTradeList(ClientboundPackets1_9_3.CUSTOM_PAYLOAD);
         registerContainerClick(ServerboundPackets1_9_3.CONTAINER_CLICK);
         registerSetCreativeModeSlot(ServerboundPackets1_9_3.SET_CREATIVE_MODE_SLOT);
     }
 
     @Override
     public Item handleItemToClient(UserConnection connection, Item item) {
-        if (item != null && item.isEmpty()) {
-            // Map empty items to null
-            return null;
+        if (item != null && item.amount() <= 0) {
+            CompoundTag tag = item.tag();
+            if (tag == null) {
+                item.setTag(tag = new CompoundTag());
+            }
+            tag.putByte(nbtTagName(), (byte) item.amount());
+            item.setAmount(1);
         }
         EntityMappings1_11.toClientItem(item);
         return item;
@@ -84,8 +60,16 @@ public class ItemPacketRewriter1_11 extends ItemRewriter<ClientboundPackets1_9_3
 
     @Override
     public Item handleItemToServer(UserConnection connection, Item item) {
+        if (item == null) {
+            return null;
+        }
+        if (item.tag() != null && item.tag().contains(nbtTagName())) {
+            item.setAmount(item.tag().<ByteTag>removeUnchecked(nbtTagName()).asByte());
+            if (item.tag().isEmpty()) {
+                item.setTag(null);
+            }
+        }
         EntityMappings1_11.toServerItem(item);
-        if (item == null) return null;
         boolean newItem = item.identifier() >= 218 && item.identifier() <= 234;
         newItem |= item.identifier() == 449 || item.identifier() == 450;
         if (newItem) { // Replace server-side unknown items

common/src/main/java/com/viaversion/viaversion/protocols/v1_11_1to1_12/rewriter/ItemPacketRewriter1_12.java

@@ -40,36 +40,7 @@ public class ItemPacketRewriter1_12 extends ItemRewriter<ClientboundPackets1_9_3
         registerSetSlot(ClientboundPackets1_9_3.CONTAINER_SET_SLOT);
         registerSetContent(ClientboundPackets1_9_3.CONTAINER_SET_CONTENT);
         registerSetEquippedItem(ClientboundPackets1_9_3.SET_EQUIPPED_ITEM);
-
-        // Plugin message -> Trading
-        protocol.registerClientbound(ClientboundPackets1_9_3.CUSTOM_PAYLOAD, new PacketHandlers() {
-            @Override
-            public void register() {
-                map(Types.STRING); // 0 - Channel
-
-                handlerSoftFail(wrapper -> {
-                    if (wrapper.get(Types.STRING, 0).equals("MC|TrList")) {
-                        wrapper.passthrough(Types.INT); // Passthrough Window ID
-
-                        int size = wrapper.passthrough(Types.UNSIGNED_BYTE);
-                        for (int i = 0; i < size; i++) {
-                            handleItemToClient(wrapper.user(), wrapper.passthrough(Types.ITEM1_8)); // Input Item
-                            handleItemToClient(wrapper.user(), wrapper.passthrough(Types.ITEM1_8)); // Output Item
-
-                            boolean secondItem = wrapper.passthrough(Types.BOOLEAN); // Has second item
-                            if (secondItem) {
-                                handleItemToClient(wrapper.user(), wrapper.passthrough(Types.ITEM1_8)); // Second Item
-                            }
-
-                            wrapper.passthrough(Types.BOOLEAN); // Trade disabled
-                            wrapper.passthrough(Types.INT); // Number of tools uses
-                            wrapper.passthrough(Types.INT); // Maximum number of trade uses
-                        }
-                    }
-                });
-            }
-        });
-
+        registerCustomPayloadTradeList(ClientboundPackets1_9_3.CUSTOM_PAYLOAD);
 
         protocol.registerServerbound(ServerboundPackets1_12.CONTAINER_CLICK, new PacketHandlers() {
                 @Override

common/src/main/java/com/viaversion/viaversion/protocols/v1_11to1_11_1/rewriter/ItemPacketRewriter1_11_1.java

@@ -28,7 +28,7 @@ import com.viaversion.viaversion.rewriter.ItemRewriter;
 public class ItemPacketRewriter1_11_1 extends ItemRewriter<ClientboundPackets1_9_3, ServerboundPackets1_9_3, Protocol1_11To1_11_1> {
 
     public ItemPacketRewriter1_11_1(Protocol1_11To1_11_1 protocol) {
-        super(protocol, Types.ITEM1_8, null);
+        super(protocol, Types.ITEM1_8, Types.ITEM1_8_SHORT_ARRAY);
     }
 
     @Override

common/src/main/java/com/viaversion/viaversion/protocols/v1_12_2to1_13/rewriter/ItemPacketRewriter1_13.java

@@ -51,7 +51,7 @@ import java.util.Optional;
 public class ItemPacketRewriter1_13 extends ItemRewriter<ClientboundPackets1_12_1, ServerboundPackets1_13, Protocol1_12_2To1_13> {
 
     public ItemPacketRewriter1_13(Protocol1_12_2To1_13 protocol) {
-        super(protocol, null, null);
+        super(protocol, Types.ITEM1_8, Types.ITEM1_8_SHORT_ARRAY, Types.ITEM1_13, Types.ITEM1_13_SHORT_ARRAY);
     }
 
     @Override
@@ -136,31 +136,7 @@ public class ItemPacketRewriter1_13 extends ItemRewriter<ClientboundPackets1_12_
                         return;
                     } else if (channel.equals("MC|TrList")) {
                         channel = "minecraft:trader_list";
-                        wrapper.passthrough(Types.INT); // Passthrough Window ID
-
-                        int size = wrapper.passthrough(Types.UNSIGNED_BYTE);
-                        for (int i = 0; i < size; i++) {
-                            // Input Item
-                            Item input = wrapper.read(Types.ITEM1_8);
-                            handleItemToClient(wrapper.user(), input);
-                            wrapper.write(Types.ITEM1_13, input);
-                            // Output Item
-                            Item output = wrapper.read(Types.ITEM1_8);
-                            handleItemToClient(wrapper.user(), output);
-                            wrapper.write(Types.ITEM1_13, output);
-
-                            boolean secondItem = wrapper.passthrough(Types.BOOLEAN); // Has second item
-                            if (secondItem) {
-                                // Second Item
-                                Item second = wrapper.read(Types.ITEM1_8);
-                                handleItemToClient(wrapper.user(), second);
-                                wrapper.write(Types.ITEM1_13, second);
-                            }
-
-                            wrapper.passthrough(Types.BOOLEAN); // Trade disabled
-                            wrapper.passthrough(Types.INT); // Number of tools uses
-                            wrapper.passthrough(Types.INT); // Maximum number of trade uses
-                        }
+                        handleTradeList(wrapper);
                     } else {
                         String old = channel;
                         channel = getNewPluginChannelId(channel);

common/src/main/java/com/viaversion/viaversion/protocols/v1_20_2to1_20_3/Protocol1_20_2To1_20_3.java

@@ -353,7 +353,7 @@ public final class Protocol1_20_2To1_20_3 extends AbstractProtocol<ClientboundPa
             .reader("dust", ParticleType.Readers.DUST)
             .reader("falling_dust", ParticleType.Readers.BLOCK)
             .reader("dust_color_transition", ParticleType.Readers.DUST_TRANSITION)
-            .reader("item", ParticleType.Readers.ITEM1_20_2)
+            .reader("item", ParticleType.Readers.item(Types.ITEM1_20_2))
             .reader("vibration", ParticleType.Readers.VIBRATION1_20_3)
             .reader("sculk_charge", ParticleType.Readers.SCULK_CHARGE)
             .reader("shriek", ParticleType.Readers.SHRIEK);

common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/Protocol1_20_3To1_20_5.java

@@ -253,7 +253,7 @@ public final class Protocol1_20_3To1_20_5 extends AbstractProtocol<ClientboundPa
             .reader("dust_pillar", ParticleType.Readers.BLOCK)
             .reader("falling_dust", ParticleType.Readers.BLOCK)
             .reader("dust_color_transition", ParticleType.Readers.DUST_TRANSITION)
-            .reader("item", ParticleType.Readers.ITEM1_20_5)
+            .reader("item", ParticleType.Readers.item(Types1_20_5.ITEM))
             .reader("vibration", ParticleType.Readers.VIBRATION1_20_3)
             .reader("sculk_charge", ParticleType.Readers.SCULK_CHARGE)
             .reader("shriek", ParticleType.Readers.SHRIEK)
@@ -261,21 +261,21 @@ public final class Protocol1_20_3To1_20_5 extends AbstractProtocol<ClientboundPa
         Types1_20_5.STRUCTURED_DATA.filler(this)
             .add(StructuredDataKey.CUSTOM_DATA).add(StructuredDataKey.MAX_STACK_SIZE).add(StructuredDataKey.MAX_DAMAGE)
             .add(StructuredDataKey.DAMAGE).add(StructuredDataKey.UNBREAKABLE).add(StructuredDataKey.RARITY)
-            .add(StructuredDataKey.HIDE_TOOLTIP).add(StructuredDataKey.FOOD).add(StructuredDataKey.FIRE_RESISTANT)
+            .add(StructuredDataKey.HIDE_TOOLTIP).add(StructuredDataKey.FOOD1_20_5).add(StructuredDataKey.FIRE_RESISTANT)
             .add(StructuredDataKey.CUSTOM_NAME).add(StructuredDataKey.LORE).add(StructuredDataKey.ENCHANTMENTS)
-            .add(StructuredDataKey.CAN_PLACE_ON).add(StructuredDataKey.CAN_BREAK).add(StructuredDataKey.ATTRIBUTE_MODIFIERS)
+            .add(StructuredDataKey.CAN_PLACE_ON).add(StructuredDataKey.CAN_BREAK).add(StructuredDataKey.ATTRIBUTE_MODIFIERS1_20_5)
             .add(StructuredDataKey.CUSTOM_MODEL_DATA).add(StructuredDataKey.HIDE_ADDITIONAL_TOOLTIP).add(StructuredDataKey.REPAIR_COST)
             .add(StructuredDataKey.CREATIVE_SLOT_LOCK).add(StructuredDataKey.ENCHANTMENT_GLINT_OVERRIDE).add(StructuredDataKey.INTANGIBLE_PROJECTILE)
             .add(StructuredDataKey.STORED_ENCHANTMENTS).add(StructuredDataKey.DYED_COLOR).add(StructuredDataKey.MAP_COLOR)
             .add(StructuredDataKey.MAP_ID).add(StructuredDataKey.MAP_DECORATIONS).add(StructuredDataKey.MAP_POST_PROCESSING)
-            .add(StructuredDataKey.CHARGED_PROJECTILES).add(StructuredDataKey.BUNDLE_CONTENTS).add(StructuredDataKey.POTION_CONTENTS)
+            .add(StructuredDataKey.CHARGED_PROJECTILES1_20_5).add(StructuredDataKey.BUNDLE_CONTENTS1_20_5).add(StructuredDataKey.POTION_CONTENTS)
             .add(StructuredDataKey.SUSPICIOUS_STEW_EFFECTS).add(StructuredDataKey.WRITABLE_BOOK_CONTENT).add(StructuredDataKey.WRITTEN_BOOK_CONTENT)
             .add(StructuredDataKey.TRIM).add(StructuredDataKey.DEBUG_STICK_STATE).add(StructuredDataKey.ENTITY_DATA)
             .add(StructuredDataKey.BUCKET_ENTITY_DATA).add(StructuredDataKey.BLOCK_ENTITY_DATA).add(StructuredDataKey.INSTRUMENT)
             .add(StructuredDataKey.RECIPES).add(StructuredDataKey.LODESTONE_TRACKER).add(StructuredDataKey.FIREWORK_EXPLOSION)
             .add(StructuredDataKey.FIREWORKS).add(StructuredDataKey.PROFILE).add(StructuredDataKey.NOTE_BLOCK_SOUND)
             .add(StructuredDataKey.BANNER_PATTERNS).add(StructuredDataKey.BASE_COLOR).add(StructuredDataKey.POT_DECORATIONS)
-            .add(StructuredDataKey.CONTAINER).add(StructuredDataKey.BLOCK_STATE).add(StructuredDataKey.BEES)
+            .add(StructuredDataKey.CONTAINER1_20_5).add(StructuredDataKey.BLOCK_STATE).add(StructuredDataKey.BEES)
             .add(StructuredDataKey.LOCK).add(StructuredDataKey.CONTAINER_LOOT).add(StructuredDataKey.TOOL)
             .add(StructuredDataKey.ITEM_NAME).add(StructuredDataKey.OMINOUS_BOTTLE_AMPLIFIER);
 

common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/rewriter/BlockItemPacketRewriter1_20_5.java

@@ -47,8 +47,9 @@ import com.viaversion.viaversion.api.minecraft.item.data.AdventureModePredicate;
 import com.viaversion.viaversion.api.minecraft.item.data.ArmorTrim;
 import com.viaversion.viaversion.api.minecraft.item.data.ArmorTrimMaterial;
 import com.viaversion.viaversion.api.minecraft.item.data.ArmorTrimPattern;
-import com.viaversion.viaversion.api.minecraft.item.data.AttributeModifier;
-import com.viaversion.viaversion.api.minecraft.item.data.AttributeModifiers;
+import com.viaversion.viaversion.api.minecraft.item.data.AttributeModifiers1_20_5;
+import com.viaversion.viaversion.api.minecraft.item.data.AttributeModifiers1_20_5.AttributeModifier;
+import com.viaversion.viaversion.api.minecraft.item.data.AttributeModifiers1_20_5.ModifierData;
 import com.viaversion.viaversion.api.minecraft.item.data.BannerPattern;
 import com.viaversion.viaversion.api.minecraft.item.data.BannerPatternLayer;
 import com.viaversion.viaversion.api.minecraft.item.data.Bee;
@@ -64,7 +65,6 @@ import com.viaversion.viaversion.api.minecraft.item.data.FoodEffect;
 import com.viaversion.viaversion.api.minecraft.item.data.FoodProperties;
 import com.viaversion.viaversion.api.minecraft.item.data.Instrument;
 import com.viaversion.viaversion.api.minecraft.item.data.LodestoneTracker;
-import com.viaversion.viaversion.api.minecraft.item.data.ModifierData;
 import com.viaversion.viaversion.api.minecraft.item.data.PotDecorations;
 import com.viaversion.viaversion.api.minecraft.item.data.PotionContents;
 import com.viaversion.viaversion.api.minecraft.item.data.PotionEffect;
@@ -225,18 +225,32 @@ public final class BlockItemPacketRewriter1_20_5 extends ItemRewriter<Clientboun
             wrapper.passthrough(Types.DOUBLE); // X
             wrapper.passthrough(Types.DOUBLE); // Y
             wrapper.passthrough(Types.DOUBLE); // Z
-            wrapper.passthrough(Types.FLOAT); // Offset X
-            wrapper.passthrough(Types.FLOAT); // Offset Y
-            wrapper.passthrough(Types.FLOAT); // Offset Z
+            final float offX = wrapper.passthrough(Types.FLOAT);
+            final float offY = wrapper.passthrough(Types.FLOAT);
+            final float offZ = wrapper.passthrough(Types.FLOAT);
             final float data = wrapper.passthrough(Types.FLOAT);
-            wrapper.passthrough(Types.INT); // Particle Count
+            final int count = wrapper.passthrough(Types.INT);
 
             // Read data and add it to Particle
             final ParticleMappings mappings = protocol.getMappingData().getParticleMappings();
             final int mappedId = mappings.getNewId(particleId);
             final Particle particle = new Particle(mappedId);
             if (mappedId == mappings.mappedId("entity_effect")) {
-                particle.add(Types.INT, data != 0 ? ThreadLocalRandom.current().nextInt() : 0); // rgb
+                final int color;
+                if (data == 0) {
+                    // Black
+                    color = 0;
+                } else if (count != 0) {
+                    // Randomized color
+                    color = ThreadLocalRandom.current().nextInt();
+                } else {
+                    // From offset
+                    final int red = Math.round(offX * 255);
+                    final int green = Math.round(offY * 255);
+                    final int blue = Math.round(offZ * 255);
+                    color = (red << 16) | (green << 8) | blue;
+                }
+                particle.add(Types.INT, EntityPacketRewriter1_20_5.withAlpha(color));
             } else if (particleId == mappings.id("dust_color_transition")) {
                 for (int i = 0; i < 7; i++) {
                     particle.add(Types.FLOAT, wrapper.read(Types.FLOAT));
@@ -294,7 +308,9 @@ public final class BlockItemPacketRewriter1_20_5 extends ItemRewriter<Clientboun
             protocol.getEntityRewriter().rewriteParticle(wrapper, Types1_20_3.PARTICLE, Types1_20_5.PARTICLE); // Small explosion particle
             protocol.getEntityRewriter().rewriteParticle(wrapper, Types1_20_3.PARTICLE, Types1_20_5.PARTICLE); // Large explosion particle
 
-            wrapper.write(Types.VAR_INT, 0); // "Empty" registry id to instead use the resource location that follows after
+            final String sound = wrapper.read(Types.STRING);
+            final Float range = wrapper.read(Types.OPTIONAL_FLOAT);
+            wrapper.write(Types.SOUND_EVENT, Holder.of(new SoundEvent(sound, range)));
         });
 
         protocol.registerClientbound(ClientboundPackets1_20_3.MERCHANT_OFFERS, wrapper -> {
@@ -340,7 +356,7 @@ public final class BlockItemPacketRewriter1_20_5 extends ItemRewriter<Clientboun
                 wrapper.passthrough(Types.STRING); // Recipe Identifier
 
                 wrapper.write(Types.VAR_INT, protocol.getMappingData().getRecipeSerializerMappings().mappedId(type));
-                recipeRewriter.handleRecipeType(wrapper, Key.stripMinecraftNamespace(type));
+                recipeRewriter.handleRecipeType(wrapper, type);
             }
         });
     }
@@ -355,7 +371,12 @@ public final class BlockItemPacketRewriter1_20_5 extends ItemRewriter<Clientboun
     }
 
     @Override
-    public Item handleItemToClient(final UserConnection connection, final Item item) {
+    public Item handleItemToClient(final UserConnection connection, @Nullable final Item item) {
+        if (item == null) {
+            // We no longer want null items, always unify them to empty
+            return StructuredItem.empty();
+        }
+
         // Add the original as custom data, to be re-used for creative clients as well
         final CompoundTag tag = item.tag();
         if (tag != null) {
@@ -375,7 +396,12 @@ public final class BlockItemPacketRewriter1_20_5 extends ItemRewriter<Clientboun
     }
 
     @Override
-    public Item handleItemToServer(UserConnection connection, final Item item) {
+    public @Nullable Item handleItemToServer(UserConnection connection, final Item item) {
+        if (item.isEmpty()) {
+            // Empty to null for the old protocols
+            return null;
+        }
+
         super.handleItemToServer(connection, item);
         return toOldItem(connection, item, DATA_CONVERTER);
     }
@@ -396,6 +422,10 @@ public final class BlockItemPacketRewriter1_20_5 extends ItemRewriter<Clientboun
             dataConverter.writeToTag(connection, structuredData, tag);
         }
 
+        if (tag.isEmpty()) {
+            dataItem.setTag(null);
+        }
+
         return dataItem;
     }
 
@@ -442,6 +472,8 @@ public final class BlockItemPacketRewriter1_20_5 extends ItemRewriter<Clientboun
             entityTag = entityTag.copy();
             if (entityTag.contains("variant")) {
                 entityTag.putString("id", "minecraft:painting");
+            } else if (entityTag.contains("ShowArms")) {
+                entityTag.putString("id", "minecraft:armor_stand");
             }
             data.set(StructuredDataKey.ENTITY_DATA, entityTag);
         }
@@ -503,7 +535,7 @@ public final class BlockItemPacketRewriter1_20_5 extends ItemRewriter<Clientboun
         if (attributeModifiersTag != null) {
             updateAttributes(data, attributeModifiersTag, showAttributes);
         } else if (!showAttributes) {
-            data.set(StructuredDataKey.ATTRIBUTE_MODIFIERS, new AttributeModifiers(new AttributeModifier[0], false));
+            data.set(StructuredDataKey.ATTRIBUTE_MODIFIERS1_20_5, new AttributeModifiers1_20_5(new AttributeModifier[0], false));
         }
 
         final CompoundTag fireworksTag = tag.getCompoundTag("Fireworks");
@@ -522,9 +554,9 @@ public final class BlockItemPacketRewriter1_20_5 extends ItemRewriter<Clientboun
 
         updateMobTags(data, tag);
 
-        updateItemList(connection, data, tag, "ChargedProjectiles", StructuredDataKey.CHARGED_PROJECTILES, false);
+        updateItemList(connection, data, tag, "ChargedProjectiles", StructuredDataKey.CHARGED_PROJECTILES1_20_5, false);
         if (old.identifier() == 927) {
-            updateItemList(connection, data, tag, "Items", StructuredDataKey.BUNDLE_CONTENTS, false);
+            updateItemList(connection, data, tag, "Items", StructuredDataKey.BUNDLE_CONTENTS1_20_5, false);
         }
 
         updateEnchantments(data, tag, "Enchantments", StructuredDataKey.ENCHANTMENTS, (hideFlagsValue & StructuredDataConverter.HIDE_ENCHANTMENTS) == 0);
@@ -700,7 +732,7 @@ public final class BlockItemPacketRewriter1_20_5 extends ItemRewriter<Clientboun
                 effect.getFloat("probability")
             ));
         }
-        data.set(StructuredDataKey.FOOD, new FoodProperties(nutrition, saturation, canAlwaysEat, eatSeconds, possibleEffects.toArray(new FoodEffect[0])));
+        data.set(StructuredDataKey.FOOD1_20_5, new FoodProperties(nutrition, saturation, canAlwaysEat, eatSeconds, null, possibleEffects.toArray(new FoodEffect[0])));
     }
 
     private void restoreToolFromBackup(final CompoundTag tool, final StructuredDataContainer data) {
@@ -862,7 +894,7 @@ public final class BlockItemPacketRewriter1_20_5 extends ItemRewriter<Clientboun
                 slotTypeId
             ));
         }
-        data.set(StructuredDataKey.ATTRIBUTE_MODIFIERS, new AttributeModifiers(modifiers.toArray(new AttributeModifier[0]), showInTooltip));
+        data.set(StructuredDataKey.ATTRIBUTE_MODIFIERS1_20_5, new AttributeModifiers1_20_5(modifiers.toArray(new AttributeModifier[0]), showInTooltip));
     }
 
     private PotionEffectData readPotionEffectData(final CompoundTag tag) {
@@ -1057,13 +1089,13 @@ public final class BlockItemPacketRewriter1_20_5 extends ItemRewriter<Clientboun
         data.set(StructuredDataKey.SUSPICIOUS_STEW_EFFECTS, suspiciousStewEffects);
     }
 
-    private void updateLodestoneTracker(final boolean tracked, final CompoundTag lodestonePosTag, final String lodestoneDimensionTag, final StructuredDataContainer data) {
+    private void updateLodestoneTracker(final boolean tracked, final CompoundTag lodestonePosTag, final String lodestoneDimension, final StructuredDataContainer data) {
         GlobalBlockPosition position = null;
-        if (lodestonePosTag != null && lodestoneDimensionTag != null) {
+        if (lodestonePosTag != null && lodestoneDimension != null) {
             final int x = lodestonePosTag.getInt("X");
             final int y = lodestonePosTag.getInt("Y");
             final int z = lodestonePosTag.getInt("Z");
-            position = new GlobalBlockPosition(lodestoneDimensionTag, x, y, z);
+            position = new GlobalBlockPosition(lodestoneDimension, x, y, z);
         }
         data.set(StructuredDataKey.LODESTONE_TRACKER, new LodestoneTracker(position, tracked));
     }
@@ -1182,12 +1214,12 @@ public final class BlockItemPacketRewriter1_20_5 extends ItemRewriter<Clientboun
     private Item itemFromTag(final UserConnection connection, final CompoundTag item) {
         final String id = item.getString("id");
         if (id == null) {
-            return null;
+            return StructuredItem.empty();
         }
 
         final int itemId = StructuredDataConverter.removeItemBackupTag(item, unmappedItemId(id));
         if (itemId == -1) {
-            return null;
+            return StructuredItem.empty();
         }
 
         final byte count = item.getByte("Count", (byte) 1);
@@ -1429,7 +1461,7 @@ public final class BlockItemPacketRewriter1_20_5 extends ItemRewriter<Clientboun
                 data.set(StructuredDataKey.BASE_COLOR, baseColorIntTag.asInt());
             }
 
-            updateItemList(connection, data, tag, "Items", StructuredDataKey.CONTAINER, true);
+            updateItemList(connection, data, tag, "Items", StructuredDataKey.CONTAINER1_20_5, true);
         }
 
         final Tag skullOwnerTag = tag.remove("SkullOwner");

common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/rewriter/ComponentRewriter1_20_5.java

@@ -41,8 +41,9 @@ import com.viaversion.viaversion.api.minecraft.item.data.AdventureModePredicate;
 import com.viaversion.viaversion.api.minecraft.item.data.ArmorTrim;
 import com.viaversion.viaversion.api.minecraft.item.data.ArmorTrimMaterial;
 import com.viaversion.viaversion.api.minecraft.item.data.ArmorTrimPattern;
-import com.viaversion.viaversion.api.minecraft.item.data.AttributeModifier;
-import com.viaversion.viaversion.api.minecraft.item.data.AttributeModifiers;
+import com.viaversion.viaversion.api.minecraft.item.data.AttributeModifiers1_20_5;
+import com.viaversion.viaversion.api.minecraft.item.data.AttributeModifiers1_20_5.AttributeModifier;
+import com.viaversion.viaversion.api.minecraft.item.data.AttributeModifiers1_20_5.ModifierData;
 import com.viaversion.viaversion.api.minecraft.item.data.BannerPattern;
 import com.viaversion.viaversion.api.minecraft.item.data.BannerPatternLayer;
 import com.viaversion.viaversion.api.minecraft.item.data.Bee;
@@ -58,7 +59,6 @@ import com.viaversion.viaversion.api.minecraft.item.data.FoodEffect;
 import com.viaversion.viaversion.api.minecraft.item.data.FoodProperties;
 import com.viaversion.viaversion.api.minecraft.item.data.Instrument;
 import com.viaversion.viaversion.api.minecraft.item.data.LodestoneTracker;
-import com.viaversion.viaversion.api.minecraft.item.data.ModifierData;
 import com.viaversion.viaversion.api.minecraft.item.data.PotDecorations;
 import com.viaversion.viaversion.api.minecraft.item.data.PotionContents;
 import com.viaversion.viaversion.api.minecraft.item.data.PotionEffect;
@@ -126,7 +126,7 @@ public class ComponentRewriter1_20_5<C extends ClientboundPacketType> extends Co
         register(StructuredDataKey.ENCHANTMENTS, this::convertEnchantments);
         register(StructuredDataKey.CAN_PLACE_ON, this::convertCanPlaceOn);
         register(StructuredDataKey.CAN_BREAK, this::convertCanBreak);
-        register(StructuredDataKey.ATTRIBUTE_MODIFIERS, this::convertAttributeModifiers);
+        register(StructuredDataKey.ATTRIBUTE_MODIFIERS1_20_5, this::convertAttributeModifiers);
         register(StructuredDataKey.CUSTOM_MODEL_DATA, this::convertCustomModelData);
         register(StructuredDataKey.HIDE_ADDITIONAL_TOOLTIP, this::convertHideAdditionalTooltip);
         register(StructuredDataKey.HIDE_TOOLTIP, this::convertHideTooltip);
@@ -134,7 +134,7 @@ public class ComponentRewriter1_20_5<C extends ClientboundPacketType> extends Co
         register(StructuredDataKey.ENCHANTMENT_GLINT_OVERRIDE, this::convertEnchantmentGlintOverride);
         register(StructuredDataKey.CREATIVE_SLOT_LOCK, null);
         register(StructuredDataKey.INTANGIBLE_PROJECTILE, this::convertIntangibleProjectile);
-        register(StructuredDataKey.FOOD, this::convertFood);
+        register(StructuredDataKey.FOOD1_20_5, this::convertFood);
         register(StructuredDataKey.FIRE_RESISTANT, this::convertFireResistant);
         register(StructuredDataKey.TOOL, this::convertTool);
         register(StructuredDataKey.STORED_ENCHANTMENTS, this::convertStoredEnchantments);
@@ -143,8 +143,8 @@ public class ComponentRewriter1_20_5<C extends ClientboundPacketType> extends Co
         register(StructuredDataKey.MAP_ID, this::convertMapId);
         register(StructuredDataKey.MAP_DECORATIONS, this::convertMapDecorations);
         register(StructuredDataKey.MAP_POST_PROCESSING, null);
-        register(StructuredDataKey.CHARGED_PROJECTILES, this::convertChargedProjectiles);
-        register(StructuredDataKey.BUNDLE_CONTENTS, this::convertBundleContents);
+        register(StructuredDataKey.CHARGED_PROJECTILES1_20_5, this::convertChargedProjectiles);
+        register(StructuredDataKey.BUNDLE_CONTENTS1_20_5, this::convertBundleContents);
         register(StructuredDataKey.POTION_CONTENTS, this::convertPotionContents);
         register(StructuredDataKey.SUSPICIOUS_STEW_EFFECTS, this::convertSuspiciousStewEffects);
         register(StructuredDataKey.WRITABLE_BOOK_CONTENT, this::convertWritableBookContent);
@@ -165,7 +165,7 @@ public class ComponentRewriter1_20_5<C extends ClientboundPacketType> extends Co
         register(StructuredDataKey.BANNER_PATTERNS, this::convertBannerPatterns);
         register(StructuredDataKey.BASE_COLOR, this::convertBaseColor);
         register(StructuredDataKey.POT_DECORATIONS, this::convertPotDecorations);
-        register(StructuredDataKey.CONTAINER, this::convertContainer);
+        register(StructuredDataKey.CONTAINER1_20_5, this::convertContainer);
         register(StructuredDataKey.BLOCK_STATE, this::convertBlockState);
         register(StructuredDataKey.BEES, this::convertBees);
         register(StructuredDataKey.LOCK, this::convertLock);
@@ -446,7 +446,7 @@ public class ComponentRewriter1_20_5<C extends ClientboundPacketType> extends Co
         return convertCanPlaceOn(value);
     }
 
-    protected CompoundTag convertAttributeModifiers(final AttributeModifiers value) {
+    protected CompoundTag convertAttributeModifiers(final AttributeModifiers1_20_5 value) {
         final CompoundTag tag = new CompoundTag();
         final ListTag<CompoundTag> modifiers = new ListTag<>(CompoundTag.class);
         for (final AttributeModifier modifier : value.modifiers()) {

common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/rewriter/EntityPacketRewriter1_20_5.java

@@ -387,7 +387,7 @@ public final class EntityPacketRewriter1_20_5 extends EntityRewriter<Clientbound
         }
     }
 
-    private int withAlpha(final int rgb) {
+    static int withAlpha(final int rgb) {
         return 255 << 24 | rgb & 0xffffff;
     }
 
@@ -412,13 +412,12 @@ public final class EntityPacketRewriter1_20_5 extends EntityRewriter<Clientbound
             Types1_20_5.ENTITY_DATA_TYPES.blockStateType,
             Types1_20_5.ENTITY_DATA_TYPES.optionalBlockStateType,
             Types1_20_5.ENTITY_DATA_TYPES.particleType,
-            null
+            null,
+            Types1_20_5.ENTITY_DATA_TYPES.componentType,
+            Types1_20_5.ENTITY_DATA_TYPES.optionalComponentType
         );
         registerBlockStateHandler(EntityTypes1_20_5.ABSTRACT_MINECART, 11);
 
-        filter().dataType(Types1_20_5.ENTITY_DATA_TYPES.componentType).handler((event, meta) -> protocol.getComponentRewriter().processTag(event.user(), meta.value()));
-        filter().dataType(Types1_20_5.ENTITY_DATA_TYPES.optionalComponentType).handler((event, meta) -> protocol.getComponentRewriter().processTag(event.user(), meta.value()));
-
         filter().type(EntityTypes1_20_5.LIVING_ENTITY).index(10).handler((event, meta) -> {
             final int effectColor = meta.value();
             if (effectColor == 0) {

common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/rewriter/StructuredDataConverter.java

@@ -35,7 +35,7 @@ import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.minecraft.item.data.AdventureModePredicate;
 import com.viaversion.viaversion.api.minecraft.item.data.ArmorTrimMaterial;
 import com.viaversion.viaversion.api.minecraft.item.data.ArmorTrimPattern;
-import com.viaversion.viaversion.api.minecraft.item.data.AttributeModifier;
+import com.viaversion.viaversion.api.minecraft.item.data.AttributeModifiers1_20_5.AttributeModifier;
 import com.viaversion.viaversion.api.minecraft.item.data.BannerPattern;
 import com.viaversion.viaversion.api.minecraft.item.data.BannerPatternLayer;
 import com.viaversion.viaversion.api.minecraft.item.data.Bee;
@@ -128,7 +128,7 @@ public final class StructuredDataConverter {
         });
         register(StructuredDataKey.ENCHANTMENTS, (data, tag) -> convertEnchantments(data, tag, false));
         register(StructuredDataKey.STORED_ENCHANTMENTS, (data, tag) -> convertEnchantments(data, tag, true));
-        register(StructuredDataKey.ATTRIBUTE_MODIFIERS, (data, tag) -> {
+        register(StructuredDataKey.ATTRIBUTE_MODIFIERS1_20_5, (data, tag) -> {
             final ListTag<CompoundTag> modifiers = new ListTag<>(CompoundTag.class);
             for (int i = 0; i < data.modifiers().length; i++) {
                 final AttributeModifier modifier = data.modifiers()[i];
@@ -218,8 +218,13 @@ public final class StructuredDataConverter {
             }
         });
         register(StructuredDataKey.BASE_COLOR, (data, tag) -> getBlockEntityTag(tag).putInt("Base", data));
-        register(StructuredDataKey.CHARGED_PROJECTILES, (connection, data, tag) -> convertItemList(connection, data, tag, "ChargedProjectiles"));
-        register(StructuredDataKey.BUNDLE_CONTENTS, (connection, data, tag) -> convertItemList(connection, data, tag, "Items"));
+        register(StructuredDataKey.CHARGED_PROJECTILES1_20_5, (connection, data, tag) -> {
+            convertItemList(connection, data, tag, "ChargedProjectiles");
+            if (data.length != 0) {
+                tag.putBoolean("Charged", true);
+            }
+        });
+        register(StructuredDataKey.BUNDLE_CONTENTS1_20_5, (connection, data, tag) -> convertItemList(connection, data, tag, "Items"));
         register(StructuredDataKey.LODESTONE_TRACKER, (data, tag) -> {
             tag.putBoolean("LodestoneTracked", data.tracked());
             if (data.position() != null) {
@@ -494,7 +499,7 @@ public final class StructuredDataConverter {
             }
             getBlockEntityTag(tag, "banner").put("Patterns", patternsTag);
         });
-        register(StructuredDataKey.CONTAINER, (connection, data, tag) -> convertItemList(connection, data, getBlockEntityTag(tag), "Items"));
+        register(StructuredDataKey.CONTAINER1_20_5, (connection, data, tag) -> convertItemList(connection, data, getBlockEntityTag(tag), "Items"));
         register(StructuredDataKey.CAN_PLACE_ON, (data, tag) -> convertBlockPredicates(tag, data, "CanPlaceOn", HIDE_CAN_PLACE_ON));
         register(StructuredDataKey.CAN_BREAK, (data, tag) -> convertBlockPredicates(tag, data, "CanDestroy", HIDE_CAN_DESTROY));
         register(StructuredDataKey.MAP_POST_PROCESSING, (data, tag) -> {
@@ -596,7 +601,7 @@ public final class StructuredDataConverter {
                 getBackupTag(tag).putInt("rarity", data);
             }
         });
-        register(StructuredDataKey.FOOD, (data, tag) -> {
+        register(StructuredDataKey.FOOD1_20_5, (data, tag) -> {
             if (backupInconvertibleData) {
                 final CompoundTag backupTag = new CompoundTag();
                 backupTag.putInt("nutrition", data.nutrition());

common/src/main/java/com/viaversion/viaversion/protocols/v1_20_5to1_21/Protocol1_20_5To1_21.java

@@ -0,0 +1,261 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2024 ViaVersion and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.viaversion.viaversion.protocols.v1_20_5to1_21;
+
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.minecraft.Holder;
+import com.viaversion.viaversion.api.minecraft.RegistryType;
+import com.viaversion.viaversion.api.minecraft.data.StructuredDataKey;
+import com.viaversion.viaversion.api.minecraft.entities.EntityTypes1_20_5;
+import com.viaversion.viaversion.api.minecraft.item.data.ChatType;
+import com.viaversion.viaversion.api.protocol.AbstractProtocol;
+import com.viaversion.viaversion.api.protocol.packet.provider.PacketTypesProvider;
+import com.viaversion.viaversion.api.protocol.packet.provider.SimplePacketTypesProvider;
+import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.api.type.types.misc.ParticleType;
+import com.viaversion.viaversion.api.type.types.version.Types1_21;
+import com.viaversion.viaversion.data.entity.EntityTrackerBase;
+import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ClientboundConfigurationPackets1_20_5;
+import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ClientboundPacket1_20_5;
+import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ClientboundPackets1_20_5;
+import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ServerboundConfigurationPackets1_20_5;
+import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ServerboundPacket1_20_5;
+import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ServerboundPackets1_20_5;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.data.AttributeModifierMappings1_21;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.data.MappingData1_21;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.packet.ClientboundConfigurationPackets1_21;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.packet.ClientboundPacket1_21;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.packet.ClientboundPackets1_21;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.rewriter.BlockItemPacketRewriter1_21;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.rewriter.ComponentRewriter1_21;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.rewriter.EntityPacketRewriter1_21;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.storage.EfficiencyAttributeStorage;
+import com.viaversion.viaversion.rewriter.ComponentRewriter;
+import com.viaversion.viaversion.rewriter.SoundRewriter;
+import com.viaversion.viaversion.rewriter.StatisticsRewriter;
+import com.viaversion.viaversion.rewriter.TagRewriter;
+import com.viaversion.viaversion.util.Key;
+import com.viaversion.viaversion.util.UUIDUtil;
+import java.util.Locale;
+import java.util.UUID;
+
+import static com.viaversion.viaversion.util.ProtocolUtil.packetTypeMap;
+
+public final class Protocol1_20_5To1_21 extends AbstractProtocol<ClientboundPacket1_20_5, ClientboundPacket1_21, ServerboundPacket1_20_5, ServerboundPacket1_20_5> {
+
+    public static final MappingData1_21 MAPPINGS = new MappingData1_21();
+    private final EntityPacketRewriter1_21 entityRewriter = new EntityPacketRewriter1_21(this);
+    private final BlockItemPacketRewriter1_21 itemRewriter = new BlockItemPacketRewriter1_21(this);
+    private final TagRewriter<ClientboundPacket1_20_5> tagRewriter = new TagRewriter<>(this);
+    private final ComponentRewriter<ClientboundPacket1_20_5> componentRewriter = new ComponentRewriter1_21(this);
+
+    public Protocol1_20_5To1_21() {
+        super(ClientboundPacket1_20_5.class, ClientboundPacket1_21.class, ServerboundPacket1_20_5.class, ServerboundPacket1_20_5.class);
+    }
+
+    @Override
+    protected void registerPackets() {
+        super.registerPackets();
+
+        tagRewriter.registerGeneric(ClientboundPackets1_20_5.UPDATE_TAGS);
+        tagRewriter.registerGeneric(ClientboundConfigurationPackets1_20_5.UPDATE_TAGS);
+
+        final SoundRewriter<ClientboundPacket1_20_5> soundRewriter = new SoundRewriter<>(this);
+        soundRewriter.registerSound1_19_3(ClientboundPackets1_20_5.SOUND);
+        soundRewriter.registerSound1_19_3(ClientboundPackets1_20_5.SOUND_ENTITY);
+
+        new StatisticsRewriter<>(this).register(ClientboundPackets1_20_5.AWARD_STATS);
+
+        componentRewriter.registerOpenScreen(ClientboundPackets1_20_5.OPEN_SCREEN);
+        componentRewriter.registerComponentPacket(ClientboundPackets1_20_5.SET_ACTION_BAR_TEXT);
+        componentRewriter.registerComponentPacket(ClientboundPackets1_20_5.SET_TITLE_TEXT);
+        componentRewriter.registerComponentPacket(ClientboundPackets1_20_5.SET_SUBTITLE_TEXT);
+        componentRewriter.registerBossEvent(ClientboundPackets1_20_5.BOSS_EVENT);
+        componentRewriter.registerComponentPacket(ClientboundPackets1_20_5.DISCONNECT);
+        componentRewriter.registerTabList(ClientboundPackets1_20_5.TAB_LIST);
+        componentRewriter.registerPlayerCombatKill1_20(ClientboundPackets1_20_5.PLAYER_COMBAT_KILL);
+        componentRewriter.registerComponentPacket(ClientboundPackets1_20_5.SYSTEM_CHAT);
+
+        registerClientbound(ClientboundPackets1_20_5.DISGUISED_CHAT, wrapper -> {
+            componentRewriter.processTag(wrapper.user(), wrapper.passthrough(Types.TAG)); // Message
+
+            // Holder time
+            final int chatType = wrapper.read(Types.VAR_INT);
+            wrapper.write(ChatType.TYPE, Holder.of(chatType));
+        });
+        registerClientbound(ClientboundPackets1_20_5.PLAYER_CHAT, wrapper -> {
+            wrapper.passthrough(Types.UUID); // Sender
+            wrapper.passthrough(Types.VAR_INT); // Index
+            wrapper.passthrough(Types.OPTIONAL_SIGNATURE_BYTES); // Signature
+            wrapper.passthrough(Types.STRING); // Plain content
+            wrapper.passthrough(Types.LONG); // Timestamp
+            wrapper.passthrough(Types.LONG); // Salt
+
+            final int lastSeen = wrapper.passthrough(Types.VAR_INT);
+            for (int i = 0; i < lastSeen; i++) {
+                final int index = wrapper.passthrough(Types.VAR_INT);
+                if (index == 0) {
+                    wrapper.passthrough(Types.SIGNATURE_BYTES);
+                }
+            }
+
+            componentRewriter.processTag(wrapper.user(), wrapper.passthrough(Types.OPTIONAL_TAG)); // Unsigned content
+
+            final int filterMaskType = wrapper.passthrough(Types.VAR_INT);
+            if (filterMaskType == 2) {
+                wrapper.passthrough(Types.LONG_ARRAY_PRIMITIVE); // Mask
+            }
+
+            final int chatType = wrapper.read(Types.VAR_INT);
+            wrapper.write(ChatType.TYPE, Holder.of(chatType));
+        });
+
+        registerClientbound(ClientboundPackets1_20_5.UPDATE_ATTRIBUTES, wrapper -> {
+            wrapper.passthrough(Types.VAR_INT); // Entity ID
+
+            final int size = wrapper.passthrough(Types.VAR_INT);
+            for (int i = 0; i < size; i++) {
+                final int attributeId = wrapper.read(Types.VAR_INT);
+                wrapper.write(Types.VAR_INT, MAPPINGS.getNewAttributeId(attributeId));
+                wrapper.passthrough(Types.DOUBLE); // Base
+                final int modifierSize = wrapper.passthrough(Types.VAR_INT);
+                for (int j = 0; j < modifierSize; j++) {
+                    final UUID uuid = wrapper.read(Types.UUID);
+                    wrapper.write(Types.STRING, mapAttributeUUID(uuid, null));
+                    wrapper.passthrough(Types.DOUBLE); // Amount
+                    wrapper.passthrough(Types.BYTE); // Operation
+                }
+            }
+        });
+
+        registerClientbound(ClientboundPackets1_20_5.PROJECTILE_POWER, wrapper -> {
+            wrapper.passthrough(Types.VAR_INT); // Id
+            final double xPower = wrapper.read(Types.DOUBLE);
+            final double yPower = wrapper.read(Types.DOUBLE);
+            final double zPower = wrapper.read(Types.DOUBLE);
+            final double accelerationPower = Math.sqrt(xPower * xPower + yPower * yPower + zPower * zPower);
+            wrapper.write(Types.DOUBLE, accelerationPower);
+        });
+    }
+
+    public static String mapAttributeUUID(final UUID uuid, final String name) {
+        String id = AttributeModifierMappings1_21.uuidToId(uuid);
+        if (id != null) {
+            return id;
+        }
+        if (name != null) {
+            id = AttributeModifierMappings1_21.nameToId(name);
+        }
+        return id != null ? id : uuid.toString().toLowerCase(Locale.ROOT);
+    }
+
+    public static UUID mapAttributeId(final String id) {
+        UUID uuid = AttributeModifierMappings1_21.idToUuid(id);
+        if (uuid != null) {
+            return uuid;
+        }
+
+        uuid = UUIDUtil.parseUUID(Key.stripNamespace(id).toUpperCase(Locale.ROOT));
+        return uuid != null ? uuid : UUID.randomUUID();
+    }
+
+    @Override
+    protected void onMappingDataLoaded() {
+        super.onMappingDataLoaded();
+
+        Types1_21.PARTICLE.filler(this)
+            .reader("block", ParticleType.Readers.BLOCK)
+            .reader("block_marker", ParticleType.Readers.BLOCK)
+            .reader("dust", ParticleType.Readers.DUST)
+            .reader("dust_pillar", ParticleType.Readers.BLOCK)
+            .reader("falling_dust", ParticleType.Readers.BLOCK)
+            .reader("dust_color_transition", ParticleType.Readers.DUST_TRANSITION)
+            .reader("item", ParticleType.Readers.item(Types1_21.ITEM))
+            .reader("vibration", ParticleType.Readers.VIBRATION1_20_3)
+            .reader("sculk_charge", ParticleType.Readers.SCULK_CHARGE)
+            .reader("shriek", ParticleType.Readers.SHRIEK)
+            .reader("entity_effect", ParticleType.Readers.COLOR);
+        Types1_21.STRUCTURED_DATA.filler(this)
+            .add(StructuredDataKey.CUSTOM_DATA).add(StructuredDataKey.MAX_STACK_SIZE).add(StructuredDataKey.MAX_DAMAGE)
+            .add(StructuredDataKey.DAMAGE).add(StructuredDataKey.UNBREAKABLE).add(StructuredDataKey.RARITY)
+            .add(StructuredDataKey.HIDE_TOOLTIP).add(StructuredDataKey.FIRE_RESISTANT)
+            .add(StructuredDataKey.CUSTOM_NAME).add(StructuredDataKey.LORE).add(StructuredDataKey.ENCHANTMENTS)
+            .add(StructuredDataKey.CAN_PLACE_ON).add(StructuredDataKey.CAN_BREAK)
+            .add(StructuredDataKey.CUSTOM_MODEL_DATA).add(StructuredDataKey.HIDE_ADDITIONAL_TOOLTIP).add(StructuredDataKey.REPAIR_COST)
+            .add(StructuredDataKey.CREATIVE_SLOT_LOCK).add(StructuredDataKey.ENCHANTMENT_GLINT_OVERRIDE).add(StructuredDataKey.INTANGIBLE_PROJECTILE)
+            .add(StructuredDataKey.STORED_ENCHANTMENTS).add(StructuredDataKey.DYED_COLOR).add(StructuredDataKey.MAP_COLOR)
+            .add(StructuredDataKey.MAP_ID).add(StructuredDataKey.MAP_DECORATIONS).add(StructuredDataKey.MAP_POST_PROCESSING)
+            .add(StructuredDataKey.CHARGED_PROJECTILES1_21).add(StructuredDataKey.BUNDLE_CONTENTS1_21).add(StructuredDataKey.POTION_CONTENTS)
+            .add(StructuredDataKey.SUSPICIOUS_STEW_EFFECTS).add(StructuredDataKey.WRITABLE_BOOK_CONTENT).add(StructuredDataKey.WRITTEN_BOOK_CONTENT)
+            .add(StructuredDataKey.TRIM).add(StructuredDataKey.DEBUG_STICK_STATE).add(StructuredDataKey.ENTITY_DATA)
+            .add(StructuredDataKey.BUCKET_ENTITY_DATA).add(StructuredDataKey.BLOCK_ENTITY_DATA).add(StructuredDataKey.INSTRUMENT)
+            .add(StructuredDataKey.RECIPES).add(StructuredDataKey.LODESTONE_TRACKER).add(StructuredDataKey.FIREWORK_EXPLOSION)
+            .add(StructuredDataKey.FIREWORKS).add(StructuredDataKey.PROFILE).add(StructuredDataKey.NOTE_BLOCK_SOUND)
+            .add(StructuredDataKey.BANNER_PATTERNS).add(StructuredDataKey.BASE_COLOR).add(StructuredDataKey.POT_DECORATIONS)
+            .add(StructuredDataKey.CONTAINER1_21).add(StructuredDataKey.BLOCK_STATE).add(StructuredDataKey.BEES)
+            .add(StructuredDataKey.LOCK).add(StructuredDataKey.CONTAINER_LOOT).add(StructuredDataKey.TOOL)
+            .add(StructuredDataKey.ITEM_NAME).add(StructuredDataKey.OMINOUS_BOTTLE_AMPLIFIER)
+            .add(StructuredDataKey.FOOD1_21).add(StructuredDataKey.JUKEBOX_PLAYABLE).add(StructuredDataKey.ATTRIBUTE_MODIFIERS1_21);
+
+        tagRewriter.addEmptyTags(RegistryType.BLOCK, "minecraft:blocks_wind_charge_explosions");
+        tagRewriter.addEmptyTags(RegistryType.ENTITY, "minecraft:can_turn_in_boats", "minecraft:deflects_projectiles", "minecraft:immune_to_infested",
+            "minecraft:immune_to_oozing", "minecraft:no_anger_from_wind_charge");
+        tagRewriter.addTag(RegistryType.ENCHANTMENT, "minecraft:curse", 10, 41); // Binding and vanishing curse
+    }
+
+    @Override
+    public void init(final UserConnection connection) {
+        addEntityTracker(connection, new EntityTrackerBase(connection, EntityTypes1_20_5.PLAYER));
+        connection.put(new EfficiencyAttributeStorage());
+    }
+
+    @Override
+    public MappingData1_21 getMappingData() {
+        return MAPPINGS;
+    }
+
+    @Override
+    public EntityPacketRewriter1_21 getEntityRewriter() {
+        return entityRewriter;
+    }
+
+    @Override
+    public BlockItemPacketRewriter1_21 getItemRewriter() {
+        return itemRewriter;
+    }
+
+    @Override
+    public TagRewriter<ClientboundPacket1_20_5> getTagRewriter() {
+        return tagRewriter;
+    }
+
+    @Override
+    public ComponentRewriter<ClientboundPacket1_20_5> getComponentRewriter() {
+        return componentRewriter;
+    }
+
+    @Override
+    protected PacketTypesProvider<ClientboundPacket1_20_5, ClientboundPacket1_21, ServerboundPacket1_20_5, ServerboundPacket1_20_5> createPacketTypesProvider() {
+        return new SimplePacketTypesProvider<>(
+            packetTypeMap(unmappedClientboundPacketType, ClientboundPackets1_20_5.class, ClientboundConfigurationPackets1_20_5.class),
+            packetTypeMap(mappedClientboundPacketType, ClientboundPackets1_21.class, ClientboundConfigurationPackets1_21.class),
+            packetTypeMap(mappedServerboundPacketType, ServerboundPackets1_20_5.class, ServerboundConfigurationPackets1_20_5.class),
+            packetTypeMap(unmappedServerboundPacketType, ServerboundPackets1_20_5.class, ServerboundConfigurationPackets1_20_5.class)
+        );
+    }
+}

common/src/main/java/com/viaversion/viaversion/protocols/v1_20_5to1_21/data/AttributeModifierMappings1_21.java

@@ -0,0 +1,103 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2024 ViaVersion and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.viaversion.viaversion.protocols.v1_20_5to1_21.data;
+
+import com.google.common.collect.BiMap;
+import com.google.common.collect.HashBiMap;
+import com.viaversion.viaversion.util.Key;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+public final class AttributeModifierMappings1_21 {
+    private static final Map<UUID, String> ATTRIBUTE_MODIFIER_IDS = new HashMap<>();
+    private static final Map<String, UUID> ATTRIBUTE_MODIFIER_INVERSE_IDS = new HashMap<>();
+    private static final BiMap<String, String> ATTRIBUTE_MODIFIER_NAMES = HashBiMap.create(Map.of(
+        "Random spawn bonus", "random_spawn_bonus",
+        "Random zombie-spawn bonus", "zombie_random_spawn_bonus",
+        "Leader zombie bonus", "leader_zombie_bonus",
+        "Zombie reinforcement callee charge", "reinforcement_callee_charge",
+        "Zombie reinforcement caller charge", "reinforcement_caller_charge"
+    ));
+
+    static {
+        add(-4483571535397864886L, -5989644940537681742L, "armor.body");
+        add(8144722948526719024L, -7778190119041365872L, "effect.slowness");
+        add(6967552254039378640L, -9116175396973475259L, "enchantment.aqua_affinity");
+        add(5279725409867744698L, -5150363631200102632L, "attacking");
+        add(148071211714102867L, -7685811609035173472L, "attacking");
+        add(6196088217904236654L, -7493791321850887290L, "effect.minining_fatigue");
+        add(-5084161844451524480L, -8859020046251006329L, "enchantment.soul_speed");
+        add(-7907339078496465106L, -8112074600724210224L, "enchantment.swift_sneak");
+        add(6688265815086220243L, -6545541163342161890L, "drinking");
+        add(8315164243412860989L, -6631520853640075966L, "creative_mode_block_range");
+        add(4389663563256579765L, -4827163546944004714L, "enchantment.efficiency");
+        add(6732612758648800940L, -5145707699103688244L, "effect.health_boost");
+        add(9079981369298536661L, -6728494925450710401L, "covered");
+        add(-1521481167610687786L, -8630419745734927691L, "effect.absorption");
+        add(-7473408062188862076L, -5872005994337939597L, "creative_mode_entity_range");
+        add(-3721396875562958315L, -5317020504214661337L, "effect.unluck");
+        add(-2861585646493481178L, -6113244764726669811L, "armor.leggings");
+        add(6718535547217657911L, -5386630269401489641L, "enchantment.sweeping_edge");
+        add(-7949229004988660584L, -7828611303000832459L, "effect.speed");
+        add(-8650171790042118250L, -5749650997644763080L, "enchantment.soul_speed");
+        add(551224288813600377L, -8734740027710371860L, "enchantment.respiration");
+        add(-7046399332347654691L, -6723081531683397260L, "suffocating");
+        add(7361814797886573596L, -8641397326606817395L, "sprinting");
+        add(-6972338111383059132L, -8978659762232839026L, "armor.chestplate");
+        add(-5371971015925809039L, -6062243582569928137L, "enchantment.fire_protection");
+        add(7245570952092733273L, -8449101711440750679L, "effect.strength");
+        add(-422425648963762075L, -5756800103171642205L, "base_attack_speed");
+        add(-4607081316629330256L, -7008565754814018370L, "effect.jump_boost");
+        add(271280981090454338L, -8746077033958322898L, "effect.luck");
+        add(2211131075215181206L, -5513857709499300658L, "powder_snow");
+        add(-8908768238899017377L, -8313820693701227669L, "armor.boots");
+        add(-5797418877589107702L, -6181652684028920077L, "effect.haste");
+        add(3086076556416732775L, -5150312587563650736L, "armor.helmet");
+        add(-5082757096938257406L, -4891139119377885130L, "baby");
+        add(2478452629826324956L, -7247530463494186011L, "effect.weakness");
+        add(4659420831966187055L, -5191473055587376048L, "enchantment.blast_protection");
+        add(7301951777949303281L, -6753860660653972126L, "evil");
+        add(8533189226688352746L, -8254757081029716377L, "baby");
+        add(1286946037536540352L, -5768092872487507967L, "enchantment.depth_strider");
+        add(-3801225194067177672L, -6586624321849018929L, "base_attack_damage");
+    }
+
+    public static @Nullable String uuidToId(final UUID uuid) {
+        return ATTRIBUTE_MODIFIER_IDS.get(uuid);
+    }
+
+    public static @Nullable UUID idToUuid(final String id) {
+        return ATTRIBUTE_MODIFIER_INVERSE_IDS.get(Key.stripMinecraftNamespace(id));
+    }
+
+    public static @Nullable String nameToId(final String name) {
+        return ATTRIBUTE_MODIFIER_NAMES.get(name);
+    }
+
+    public static @Nullable String idToName(final String id) {
+        return ATTRIBUTE_MODIFIER_NAMES.inverse().get(id);
+    }
+
+    private static void add(final long msb, final long lsb, final String id) {
+        final UUID uuid = new UUID(msb, lsb);
+        ATTRIBUTE_MODIFIER_IDS.put(uuid, id);
+        ATTRIBUTE_MODIFIER_INVERSE_IDS.put(id, uuid);
+    }
+}

common/src/main/java/com/viaversion/viaversion/protocols/v1_20_5to1_21/data/MappingData1_21.java

@@ -0,0 +1,57 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2024 ViaVersion and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.viaversion.viaversion.protocols.v1_20_5to1_21.data;
+
+import com.viaversion.nbt.tag.CompoundTag;
+import com.viaversion.nbt.tag.ListTag;
+import com.viaversion.nbt.tag.Tag;
+import com.viaversion.viaversion.api.data.MappingDataBase;
+import com.viaversion.viaversion.api.data.MappingDataLoader;
+import com.viaversion.viaversion.api.minecraft.RegistryEntry;
+import java.util.Map;
+
+public final class MappingData1_21 extends MappingDataBase {
+
+    private ListTag<CompoundTag> enchantments;
+    private CompoundTag jukeboxSongs;
+
+    public MappingData1_21() {
+        super("1.20.5", "1.21");
+    }
+
+    @Override
+    protected void loadExtras(final CompoundTag data) {
+        final CompoundTag extraMappings = MappingDataLoader.INSTANCE.loadNBT("enchantments-1.21.nbt");
+        enchantments = extraMappings.getListTag("entries", CompoundTag.class);
+        jukeboxSongs = MappingDataLoader.INSTANCE.loadNBT("jukebox-songs-1.21.nbt");
+    }
+
+    public CompoundTag enchantment(final int id) {
+        return enchantments.get(id).copy();
+    }
+
+    public RegistryEntry[] jukeboxSongs() {
+        final RegistryEntry[] entries = new RegistryEntry[jukeboxSongs.size()];
+        int i = 0;
+        for (final Map.Entry<String, Tag> entry : jukeboxSongs.entrySet()) {
+            final CompoundTag tag = (CompoundTag) entry.getValue();
+            entries[i++] = new RegistryEntry(entry.getKey(), tag.copy());
+        }
+        return entries;
+    }
+}

common/src/main/java/com/viaversion/viaversion/protocols/v1_20_5to1_21/data/Paintings1_20_5.java

@@ -0,0 +1,56 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2024 ViaVersion and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.viaversion.viaversion.protocols.v1_20_5to1_21.data;
+
+import com.viaversion.viaversion.api.minecraft.PaintingVariant;
+
+public final class Paintings1_20_5 {
+
+    public static final PaintingVariant[] PAINTINGS = {
+        new PaintingVariant(1, 1, "kebab"),
+        new PaintingVariant(1, 1, "aztec"),
+        new PaintingVariant(1, 1, "alban"),
+        new PaintingVariant(1, 1, "aztec2"),
+        new PaintingVariant(1, 1, "bomb"),
+        new PaintingVariant(1, 1, "plant"),
+        new PaintingVariant(1, 1, "wasteland"),
+        new PaintingVariant(2, 1, "pool"),
+        new PaintingVariant(2, 1, "courbet"),
+        new PaintingVariant(2, 1, "sea"),
+        new PaintingVariant(2, 1, "sunset"),
+        new PaintingVariant(2, 1, "creebet"),
+        new PaintingVariant(1, 2, "wanderer"),
+        new PaintingVariant(1, 2, "graham"),
+        new PaintingVariant(2, 2, "match"),
+        new PaintingVariant(2, 2, "bust"),
+        new PaintingVariant(2, 2, "stage"),
+        new PaintingVariant(2, 2, "void"),
+        new PaintingVariant(2, 2, "skull_and_roses"),
+        new PaintingVariant(2, 2, "wither"),
+        new PaintingVariant(4, 2, "fighters"),
+        new PaintingVariant(4, 4, "pointer"),
+        new PaintingVariant(4, 4, "pigscene"),
+        new PaintingVariant(4, 4, "burning_skull"),
+        new PaintingVariant(4, 3, "skeleton"),
+        new PaintingVariant(2, 2, "earth"),
+        new PaintingVariant(2, 2, "wind"),
+        new PaintingVariant(2, 2, "water"),
+        new PaintingVariant(2, 2, "fire"),
+        new PaintingVariant(4, 3, "donkey_kong")
+    };
+}

common/src/main/java/com/viaversion/viaversion/protocols/v1_20_5to1_21/packet/ClientboundConfigurationPackets1_21.java

@@ -0,0 +1,56 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2024 ViaVersion and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.viaversion.viaversion.protocols.v1_20_5to1_21.packet;
+
+import com.viaversion.viaversion.api.protocol.packet.State;
+
+public enum ClientboundConfigurationPackets1_21 implements ClientboundPacket1_21 {
+
+    COOKIE_REQUEST, // 0x00
+    CUSTOM_PAYLOAD, // 0x01
+    DISCONNECT, // 0x02
+    FINISH_CONFIGURATION, // 0x03
+    KEEP_ALIVE, // 0x04
+    PING, // 0x05
+    RESET_CHAT, // 0x06
+    REGISTRY_DATA, // 0x07
+    RESOURCE_PACK_POP, // 0x08
+    RESOURCE_PACK_PUSH, // 0x09
+    STORE_COOKIE, // 0x0A
+    TRANSFER, // 0x0B
+    UPDATE_ENABLED_FEATURES, // 0x0C
+    UPDATE_TAGS, // 0x0D
+    SELECT_KNOWN_PACKS, // 0x0E
+    CUSTOM_REPORT_DETAILS, // 0x0F
+    SERVER_LINKS; // 0x10
+
+    @Override
+    public int getId() {
+        return ordinal();
+    }
+
+    @Override
+    public String getName() {
+        return name();
+    }
+
+    @Override
+    public State state() {
+        return State.CONFIGURATION;
+    }
+}

common/src/main/java/com/viaversion/viaversion/protocols/v1_20_5to1_21/packet/ClientboundPacket1_21.java

@@ -0,0 +1,23 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2024 ViaVersion and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.viaversion.viaversion.protocols.v1_20_5to1_21.packet;
+
+import com.viaversion.viaversion.api.protocol.packet.ClientboundPacketType;
+
+public interface ClientboundPacket1_21 extends ClientboundPacketType {
+}

common/src/main/java/com/viaversion/viaversion/protocols/v1_20_5to1_21/packet/ClientboundPackets1_21.java

@@ -0,0 +1,156 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2024 ViaVersion and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.viaversion.viaversion.protocols.v1_20_5to1_21.packet;
+
+public enum ClientboundPackets1_21 implements ClientboundPacket1_21 {
+
+    BUNDLE_DELIMITER, // 0x00
+    ADD_ENTITY, // 0x01
+    ADD_EXPERIENCE_ORB, // 0x02
+    ANIMATE, // 0x03
+    AWARD_STATS, // 0x04
+    BLOCK_CHANGED_ACK, // 0x05
+    BLOCK_DESTRUCTION, // 0x06
+    BLOCK_ENTITY_DATA, // 0x07
+    BLOCK_EVENT, // 0x08
+    BLOCK_UPDATE, // 0x09
+    BOSS_EVENT, // 0x0A
+    CHANGE_DIFFICULTY, // 0x0B
+    CHUNK_BATCH_FINISHED, // 0x0C
+    CHUNK_BATCH_START, // 0x0D
+    CHUNKS_BIOMES, // 0x0E
+    CLEAR_TITLES, // 0x0F
+    COMMAND_SUGGESTIONS, // 0x10
+    COMMANDS, // 0x11
+    CONTAINER_CLOSE, // 0x12
+    CONTAINER_SET_CONTENT, // 0x13
+    CONTAINER_SET_DATA, // 0x14
+    CONTAINER_SET_SLOT, // 0x15
+    COOKIE_REQUEST, // 0x16
+    COOLDOWN, // 0x17
+    CUSTOM_CHAT_COMPLETIONS, // 0x18
+    CUSTOM_PAYLOAD, // 0x19
+    DAMAGE_EVENT, // 0x1A
+    DEBUG_SAMPLE, // 0x1B
+    DELETE_CHAT, // 0x1C
+    DISCONNECT, // 0x1D
+    DISGUISED_CHAT, // 0x1E
+    ENTITY_EVENT, // 0x1F
+    EXPLODE, // 0x20
+    FORGET_LEVEL_CHUNK, // 0x21
+    GAME_EVENT, // 0x22
+    HORSE_SCREEN_OPEN, // 0x23
+    HURT_ANIMATION, // 0x24
+    INITIALIZE_BORDER, // 0x25
+    KEEP_ALIVE, // 0x26
+    LEVEL_CHUNK_WITH_LIGHT, // 0x27
+    LEVEL_EVENT, // 0x28
+    LEVEL_PARTICLES, // 0x29
+    LIGHT_UPDATE, // 0x2A
+    LOGIN, // 0x2B
+    MAP_ITEM_DATA, // 0x2C
+    MERCHANT_OFFERS, // 0x2D
+    MOVE_ENTITY_POS, // 0x2E
+    MOVE_ENTITY_POS_ROT, // 0x2F
+    MOVE_ENTITY_ROT, // 0x30
+    MOVE_VEHICLE, // 0x31
+    OPEN_BOOK, // 0x32
+    OPEN_SCREEN, // 0x33
+    OPEN_SIGN_EDITOR, // 0x34
+    PING, // 0x35
+    PONG_RESPONSE, // 0x36
+    PLACE_GHOST_RECIPE, // 0x37
+    PLAYER_ABILITIES, // 0x38
+    PLAYER_CHAT, // 0x39
+    PLAYER_COMBAT_END, // 0x3A
+    PLAYER_COMBAT_ENTER, // 0x3B
+    PLAYER_COMBAT_KILL, // 0x3C
+    PLAYER_INFO_REMOVE, // 0x3D
+    PLAYER_INFO_UPDATE, // 0x3E
+    PLAYER_LOOK_AT, // 0x3F
+    PLAYER_POSITION, // 0x40
+    RECIPE, // 0x41
+    REMOVE_ENTITIES, // 0x42
+    REMOVE_MOB_EFFECT, // 0x43
+    RESET_SCORE, // 0x44
+    RESOURCE_PACK_POP, // 0x45
+    RESOURCE_PACK_PUSH, // 0x46
+    RESPAWN, // 0x47
+    ROTATE_HEAD, // 0x48
+    SECTION_BLOCKS_UPDATE, // 0x49
+    SELECT_ADVANCEMENTS_TAB, // 0x4A
+    SERVER_DATA, // 0x4B
+    SET_ACTION_BAR_TEXT, // 0x4C
+    SET_BORDER_CENTER, // 0x4D
+    SET_BORDER_LERP_SIZE, // 0x4E
+    SET_BORDER_SIZE, // 0x4F
+    SET_BORDER_WARNING_DELAY, // 0x50
+    SET_BORDER_WARNING_DISTANCE, // 0x51
+    SET_CAMERA, // 0x52
+    SET_CARRIED_ITEM, // 0x53
+    SET_CHUNK_CACHE_CENTER, // 0x54
+    SET_CHUNK_CACHE_RADIUS, // 0x55
+    SET_DEFAULT_SPAWN_POSITION, // 0x56
+    SET_DISPLAY_OBJECTIVE, // 0x57
+    SET_ENTITY_DATA, // 0x58
+    SET_ENTITY_LINK, // 0x59
+    SET_ENTITY_MOTION, // 0x5A
+    SET_EQUIPMENT, // 0x5B
+    SET_EXPERIENCE, // 0x5C
+    SET_HEALTH, // 0x5D
+    SET_OBJECTIVE, // 0x5E
+    SET_PASSENGERS, // 0x5F
+    SET_PLAYER_TEAM, // 0x60
+    SET_SCORE, // 0x61
+    SET_SIMULATION_DISTANCE, // 0x62
+    SET_SUBTITLE_TEXT, // 0x63
+    SET_TIME, // 0x64
+    SET_TITLE_TEXT, // 0x65
+    SET_TITLES_ANIMATION, // 0x66
+    SOUND_ENTITY, // 0x67
+    SOUND, // 0x68
+    START_CONFIGURATION, // 0x69
+    STOP_SOUND, // 0x6A
+    STORE_COOKIE, // 0x6B
+    SYSTEM_CHAT, // 0x6C
+    TAB_LIST, // 0x6D
+    TAG_QUERY, // 0x6E
+    TAKE_ITEM_ENTITY, // 0x6F
+    TELEPORT_ENTITY, // 0x70
+    TICKING_STATE, // 0x71
+    TICKING_STEP, // 0x72
+    TRANSFER, // 0x73
+    UPDATE_ADVANCEMENTS, // 0x74
+    UPDATE_ATTRIBUTES, // 0x75
+    UPDATE_MOB_EFFECT, // 0x76
+    UPDATE_RECIPES, // 0x77
+    UPDATE_TAGS, // 0x78
+    PROJECTILE_POWER, // 0x79
+    CUSTOM_REPORT_DETAILS, // 0x7A
+    SERVER_LINKS; // 0x7B
+
+    @Override
+    public int getId() {
+        return ordinal();
+    }
+
+    @Override
+    public String getName() {
+        return name();
+    }
+}

common/src/main/java/com/viaversion/viaversion/protocols/v1_20_5to1_21/rewriter/BlockItemPacketRewriter1_21.java

@@ -0,0 +1,179 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2024 ViaVersion and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.viaversion.viaversion.protocols.v1_20_5to1_21.rewriter;
+
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.minecraft.data.StructuredDataContainer;
+import com.viaversion.viaversion.api.minecraft.data.StructuredDataKey;
+import com.viaversion.viaversion.api.minecraft.item.Item;
+import com.viaversion.viaversion.api.minecraft.item.data.AttributeModifiers1_20_5;
+import com.viaversion.viaversion.api.minecraft.item.data.AttributeModifiers1_21;
+import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.api.type.types.chunk.ChunkType1_20_2;
+import com.viaversion.viaversion.api.type.types.version.Types1_20_5;
+import com.viaversion.viaversion.api.type.types.version.Types1_21;
+import com.viaversion.viaversion.protocols.v1_20_2to1_20_3.rewriter.RecipeRewriter1_20_3;
+import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ClientboundPacket1_20_5;
+import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ClientboundPackets1_20_5;
+import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ServerboundPacket1_20_5;
+import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ServerboundPackets1_20_5;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.Protocol1_20_5To1_21;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.data.AttributeModifierMappings1_21;
+import com.viaversion.viaversion.rewriter.BlockRewriter;
+import com.viaversion.viaversion.rewriter.StructuredItemRewriter;
+import java.util.Arrays;
+import java.util.List;
+
+public final class BlockItemPacketRewriter1_21 extends StructuredItemRewriter<ClientboundPacket1_20_5, ServerboundPacket1_20_5, Protocol1_20_5To1_21> {
+
+    private static final List<String> DISCS = List.of("11", "13", "5", "blocks", "cat", "chirp", "far", "mall", "mellohi", "otherside", "pigstep", "relic", "stal", "strad", "wait", "ward");
+
+    public BlockItemPacketRewriter1_21(final Protocol1_20_5To1_21 protocol) {
+        super(protocol, Types1_20_5.ITEM, Types1_20_5.ITEM_ARRAY, Types1_21.ITEM, Types1_21.ITEM_ARRAY);
+    }
+
+    @Override
+    public void registerPackets() {
+        final BlockRewriter<ClientboundPacket1_20_5> blockRewriter = BlockRewriter.for1_20_2(protocol);
+        blockRewriter.registerBlockEvent(ClientboundPackets1_20_5.BLOCK_EVENT);
+        blockRewriter.registerBlockUpdate(ClientboundPackets1_20_5.BLOCK_UPDATE);
+        blockRewriter.registerSectionBlocksUpdate1_20(ClientboundPackets1_20_5.SECTION_BLOCKS_UPDATE);
+        blockRewriter.registerLevelChunk1_19(ClientboundPackets1_20_5.LEVEL_CHUNK_WITH_LIGHT, ChunkType1_20_2::new);
+        blockRewriter.registerBlockEntityData(ClientboundPackets1_20_5.BLOCK_ENTITY_DATA);
+
+        registerCooldown(ClientboundPackets1_20_5.COOLDOWN);
+        registerSetContent1_17_1(ClientboundPackets1_20_5.CONTAINER_SET_CONTENT);
+        registerSetSlot1_17_1(ClientboundPackets1_20_5.CONTAINER_SET_SLOT);
+        registerAdvancements1_20_3(ClientboundPackets1_20_5.UPDATE_ADVANCEMENTS);
+        registerSetEquipment(ClientboundPackets1_20_5.SET_EQUIPMENT);
+        registerContainerClick1_17_1(ServerboundPackets1_20_5.CONTAINER_CLICK);
+        registerMerchantOffers1_20_5(ClientboundPackets1_20_5.MERCHANT_OFFERS, Types1_20_5.ITEM_COST, Types1_21.ITEM_COST, Types1_20_5.OPTIONAL_ITEM_COST, Types1_21.OPTIONAL_ITEM_COST);
+        registerSetCreativeModeSlot(ServerboundPackets1_20_5.SET_CREATIVE_MODE_SLOT);
+        registerContainerSetData(ClientboundPackets1_20_5.CONTAINER_SET_DATA);
+        registerLevelParticles1_20_5(ClientboundPackets1_20_5.LEVEL_PARTICLES, Types1_20_5.PARTICLE, Types1_21.PARTICLE);
+        registerExplosion(ClientboundPackets1_20_5.EXPLODE, Types1_20_5.PARTICLE, Types1_21.PARTICLE); // Rewrites the included sound and particles
+
+        protocol.registerClientbound(ClientboundPackets1_20_5.HORSE_SCREEN_OPEN, wrapper -> {
+            wrapper.passthrough(Types.UNSIGNED_BYTE); // Container id
+
+            // Now written as columns
+            final int size = wrapper.read(Types.VAR_INT);
+            wrapper.write(Types.VAR_INT, Math.max(1, (size - 1) / 3));
+        });
+
+        protocol.registerClientbound(ClientboundPackets1_20_5.LEVEL_EVENT, wrapper -> {
+            final int id = wrapper.passthrough(Types.INT);
+            wrapper.passthrough(Types.BLOCK_POSITION1_14);
+
+            final int data = wrapper.read(Types.INT);
+            if (id == 1010) {
+                final int jukeboxSong = itemToJubeboxSong(data);
+                if (jukeboxSong == -1) {
+                    wrapper.cancel();
+                    return;
+                }
+
+                wrapper.write(Types.INT, jukeboxSong);
+            } else if (id == 2001) {
+                wrapper.write(Types.INT, protocol.getMappingData().getNewBlockStateId(data));
+            } else {
+                wrapper.write(Types.INT, data);
+            }
+        });
+
+        protocol.registerServerbound(ServerboundPackets1_20_5.USE_ITEM, wrapper -> {
+            wrapper.passthrough(Types.VAR_INT); // Hand
+            wrapper.passthrough(Types.VAR_INT); // Sequence
+            wrapper.read(Types.FLOAT); // Y rotation
+            wrapper.read(Types.FLOAT); // X rotation
+        });
+
+        new RecipeRewriter1_20_3<>(protocol).register1_20_5(ClientboundPackets1_20_5.UPDATE_RECIPES);
+    }
+
+    @Override
+    public Item handleItemToClient(final UserConnection connection, final Item item) {
+        if (item.isEmpty()) {
+            return item;
+        }
+
+        super.handleItemToClient(connection, item);
+        updateItemData(item);
+        return item;
+    }
+
+    public static void updateItemData(final Item item) {
+        final StructuredDataContainer dataContainer = item.dataContainer();
+        dataContainer.replaceKey(StructuredDataKey.FOOD1_20_5, StructuredDataKey.FOOD1_21);
+        dataContainer.replaceKey(StructuredDataKey.CONTAINER1_20_5, StructuredDataKey.CONTAINER1_21);
+        dataContainer.replaceKey(StructuredDataKey.CHARGED_PROJECTILES1_20_5, StructuredDataKey.CHARGED_PROJECTILES1_21);
+        dataContainer.replaceKey(StructuredDataKey.BUNDLE_CONTENTS1_20_5, StructuredDataKey.BUNDLE_CONTENTS1_21);
+        dataContainer.replace(StructuredDataKey.ATTRIBUTE_MODIFIERS1_20_5, StructuredDataKey.ATTRIBUTE_MODIFIERS1_21, attributeModifiers -> {
+            final AttributeModifiers1_21.AttributeModifier[] modifiers = Arrays.stream(attributeModifiers.modifiers()).map(modifier -> {
+                final AttributeModifiers1_20_5.ModifierData modData = modifier.modifier();
+                final AttributeModifiers1_21.ModifierData updatedModData = new AttributeModifiers1_21.ModifierData(Protocol1_20_5To1_21.mapAttributeUUID(modData.uuid(), modData.name()), modData.amount(), modData.operation());
+                return new AttributeModifiers1_21.AttributeModifier(modifier.attribute(), updatedModData, modifier.slotType());
+            }).toArray(AttributeModifiers1_21.AttributeModifier[]::new);
+            return new AttributeModifiers1_21(modifiers, attributeModifiers.showInTooltip());
+        });
+    }
+
+    @Override
+    public Item handleItemToServer(final UserConnection connection, final Item item) {
+        if (item.isEmpty()) {
+            return item;
+        }
+
+        super.handleItemToServer(connection, item);
+        downgradeItemData(item);
+        return item;
+    }
+
+    public static void downgradeItemData(final Item item) {
+        final StructuredDataContainer dataContainer = item.dataContainer();
+        dataContainer.replaceKey(StructuredDataKey.FOOD1_21, StructuredDataKey.FOOD1_20_5);
+        dataContainer.replaceKey(StructuredDataKey.CONTAINER1_21, StructuredDataKey.CONTAINER1_20_5);
+        dataContainer.replaceKey(StructuredDataKey.CHARGED_PROJECTILES1_21, StructuredDataKey.CHARGED_PROJECTILES1_20_5);
+        dataContainer.replaceKey(StructuredDataKey.BUNDLE_CONTENTS1_21, StructuredDataKey.BUNDLE_CONTENTS1_20_5);
+        dataContainer.remove(StructuredDataKey.JUKEBOX_PLAYABLE);
+        dataContainer.replace(StructuredDataKey.ATTRIBUTE_MODIFIERS1_21, StructuredDataKey.ATTRIBUTE_MODIFIERS1_20_5, attributeModifiers -> {
+            final AttributeModifiers1_20_5.AttributeModifier[] modifiers = Arrays.stream(attributeModifiers.modifiers()).map(modifier -> {
+                final AttributeModifiers1_21.ModifierData modData = modifier.modifier();
+                final String name = AttributeModifierMappings1_21.idToName(modData.id());
+                final AttributeModifiers1_20_5.ModifierData updatedModData = new AttributeModifiers1_20_5.ModifierData(
+                    Protocol1_20_5To1_21.mapAttributeId(modData.id()),
+                    name != null ? name : modData.id(),
+                    modData.amount(),
+                    modData.operation()
+                );
+                return new AttributeModifiers1_20_5.AttributeModifier(modifier.attribute(), updatedModData, modifier.slotType());
+            }).toArray(AttributeModifiers1_20_5.AttributeModifier[]::new);
+            return new AttributeModifiers1_20_5(modifiers, attributeModifiers.showInTooltip());
+        });
+    }
+
+    private int itemToJubeboxSong(final int id) {
+        String identifier = Protocol1_20_5To1_21.MAPPINGS.getFullItemMappings().identifier(id);
+        if (!identifier.contains("music_disc_")) {
+            return -1;
+        }
+
+        identifier = identifier.substring("minecraft:music_disc_".length());
+        return DISCS.indexOf(identifier);
+    }
+}

common/src/main/java/com/viaversion/viaversion/protocols/v1_20_5to1_21/rewriter/ComponentRewriter1_21.java

@@ -0,0 +1,60 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2024 ViaVersion and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.viaversion.viaversion.protocols.v1_20_5to1_21.rewriter;
+
+import com.viaversion.nbt.tag.CompoundTag;
+import com.viaversion.nbt.tag.ListTag;
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ClientboundPacket1_20_5;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.Protocol1_20_5To1_21;
+import com.viaversion.viaversion.rewriter.ComponentRewriter;
+import com.viaversion.viaversion.util.SerializerVersion;
+import com.viaversion.viaversion.util.TagUtil;
+import com.viaversion.viaversion.util.UUIDUtil;
+import java.util.UUID;
+
+public final class ComponentRewriter1_21 extends ComponentRewriter<ClientboundPacket1_20_5> {
+
+    public ComponentRewriter1_21(final Protocol1_20_5To1_21 protocol) {
+        super(protocol, ReadType.NBT);
+    }
+
+    @Override
+    protected void handleShowItem(final UserConnection connection, final CompoundTag componentsTag) {
+        final CompoundTag attributeModifiers = TagUtil.getNamespacedCompoundTag(componentsTag, "minecraft:attribute_modifiers");
+        if (attributeModifiers != null) {
+            final ListTag<CompoundTag> modifiers = attributeModifiers.getListTag("modifiers", CompoundTag.class);
+            for (final CompoundTag modifier : modifiers) {
+                final String name = modifier.getString("name");
+                final UUID uuid = UUIDUtil.fromIntArray(modifier.getIntArrayTag("uuid").getValue());
+                final String id = Protocol1_20_5To1_21.mapAttributeUUID(uuid, name);
+                modifier.putString("id", id);
+            }
+        }
+    }
+
+    @Override
+    protected SerializerVersion inputSerializerVersion() {
+        return SerializerVersion.V1_20_5;
+    }
+
+    @Override
+    protected SerializerVersion outputSerializerVersion() {
+        return SerializerVersion.V1_20_5;
+    }
+}

common/src/main/java/com/viaversion/viaversion/protocols/v1_20_5to1_21/rewriter/EntityPacketRewriter1_21.java

@@ -0,0 +1,160 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2024 ViaVersion and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.viaversion.viaversion.protocols.v1_20_5to1_21.rewriter;
+
+import com.viaversion.nbt.tag.CompoundTag;
+import com.viaversion.viaversion.api.minecraft.Holder;
+import com.viaversion.viaversion.api.minecraft.PaintingVariant;
+import com.viaversion.viaversion.api.minecraft.RegistryEntry;
+import com.viaversion.viaversion.api.minecraft.entities.EntityType;
+import com.viaversion.viaversion.api.minecraft.entities.EntityTypes1_20_5;
+import com.viaversion.viaversion.api.minecraft.entitydata.EntityDataType;
+import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
+import com.viaversion.viaversion.api.protocol.remapper.PacketHandlers;
+import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.api.type.types.version.Types1_20_5;
+import com.viaversion.viaversion.api.type.types.version.Types1_21;
+import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.data.Enchantments1_20_5;
+import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ClientboundConfigurationPackets1_20_5;
+import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ClientboundPacket1_20_5;
+import com.viaversion.viaversion.protocols.v1_20_3to1_20_5.packet.ClientboundPackets1_20_5;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.Protocol1_20_5To1_21;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.data.Paintings1_20_5;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.storage.EfficiencyAttributeStorage;
+import com.viaversion.viaversion.rewriter.EntityRewriter;
+import com.viaversion.viaversion.util.ArrayUtil;
+import com.viaversion.viaversion.util.Key;
+
+public final class EntityPacketRewriter1_21 extends EntityRewriter<ClientboundPacket1_20_5, Protocol1_20_5To1_21> {
+
+    public EntityPacketRewriter1_21(final Protocol1_20_5To1_21 protocol) {
+        super(protocol);
+    }
+
+    @Override
+    public void registerPackets() {
+        registerTrackerWithData1_19(ClientboundPackets1_20_5.ADD_ENTITY, EntityTypes1_20_5.FALLING_BLOCK);
+        registerSetEntityData(ClientboundPackets1_20_5.SET_ENTITY_DATA, Types1_20_5.ENTITY_DATA_LIST, Types1_21.ENTITY_DATA_LIST);
+        registerRemoveEntities(ClientboundPackets1_20_5.REMOVE_ENTITIES);
+
+        protocol.registerClientbound(ClientboundConfigurationPackets1_20_5.REGISTRY_DATA, wrapper -> {
+            final String type = Key.stripMinecraftNamespace(wrapper.passthrough(Types.STRING));
+            final RegistryEntry[] entries = wrapper.passthrough(Types.REGISTRY_ENTRY_ARRAY);
+            if (type.equals("damage_type")) {
+                // Add required damage type
+                final CompoundTag campfireDamageType = new CompoundTag();
+                campfireDamageType.putString("scaling", "when_caused_by_living_non_player");
+                campfireDamageType.putString("message_id", "inFire");
+                campfireDamageType.putFloat("exhaustion", 0.1F);
+                wrapper.set(Types.REGISTRY_ENTRY_ARRAY, 0, ArrayUtil.add(entries, new RegistryEntry("minecraft:campfire", campfireDamageType)));
+            } else {
+                handleRegistryData1_20_5(wrapper.user(), type, entries);
+            }
+        });
+
+        protocol.registerClientbound(ClientboundConfigurationPackets1_20_5.FINISH_CONFIGURATION, wrapper -> {
+            // Add new registries
+            final PacketWrapper paintingRegistryPacket = wrapper.create(ClientboundConfigurationPackets1_20_5.REGISTRY_DATA);
+            paintingRegistryPacket.write(Types.STRING, "minecraft:painting_variant");
+            final RegistryEntry[] paintingsRegistry = new RegistryEntry[Paintings1_20_5.PAINTINGS.length];
+            for (int i = 0; i < Paintings1_20_5.PAINTINGS.length; i++) {
+                final PaintingVariant painting = Paintings1_20_5.PAINTINGS[i];
+                final CompoundTag tag = new CompoundTag();
+                tag.putInt("width", painting.width());
+                tag.putInt("height", painting.height());
+                tag.putString("asset_id", painting.assetId());
+                paintingsRegistry[i] = new RegistryEntry(painting.assetId(), tag);
+            }
+            paintingRegistryPacket.write(Types.REGISTRY_ENTRY_ARRAY, paintingsRegistry);
+            paintingRegistryPacket.send(Protocol1_20_5To1_21.class);
+
+            final PacketWrapper enchantmentRegistryPacket = wrapper.create(ClientboundConfigurationPackets1_20_5.REGISTRY_DATA);
+            enchantmentRegistryPacket.write(Types.STRING, "minecraft:enchantment");
+            final RegistryEntry[] enchantmentRegistry = new RegistryEntry[Enchantments1_20_5.ENCHANTMENTS.size()];
+            for (int i = 0; i < Enchantments1_20_5.ENCHANTMENTS.size(); i++) {
+                final String key = Enchantments1_20_5.idToKey(i);
+                final CompoundTag tag = protocol.getMappingData().enchantment(i);
+                enchantmentRegistry[i] = new RegistryEntry(key, tag);
+            }
+            enchantmentRegistryPacket.write(Types.REGISTRY_ENTRY_ARRAY, enchantmentRegistry);
+            enchantmentRegistryPacket.send(Protocol1_20_5To1_21.class);
+
+            final PacketWrapper jukeboxSongsPacket = wrapper.create(ClientboundConfigurationPackets1_20_5.REGISTRY_DATA);
+            jukeboxSongsPacket.write(Types.STRING, "minecraft:jukebox_song");
+            jukeboxSongsPacket.write(Types.REGISTRY_ENTRY_ARRAY, protocol.getMappingData().jukeboxSongs());
+            jukeboxSongsPacket.send(Protocol1_20_5To1_21.class);
+        });
+
+        protocol.registerClientbound(ClientboundPackets1_20_5.LOGIN, new PacketHandlers() {
+            @Override
+            public void register() {
+                map(Types.INT); // Entity id
+                map(Types.BOOLEAN); // Hardcore
+                map(Types.STRING_ARRAY); // World List
+                map(Types.VAR_INT); // Max players
+                map(Types.VAR_INT); // View distance
+                map(Types.VAR_INT); // Simulation distance
+                map(Types.BOOLEAN); // Reduced debug info
+                map(Types.BOOLEAN); // Show death screen
+                map(Types.BOOLEAN); // Limited crafting
+                map(Types.VAR_INT); // Dimension id
+                map(Types.STRING); // World
+                handler(worldDataTrackerHandlerByKey1_20_5(3));
+                handler(playerTrackerHandler());
+                handler(wrapper -> wrapper.user().get(EfficiencyAttributeStorage.class).onLoginSent(wrapper.user()));
+            }
+        });
+
+        protocol.registerClientbound(ClientboundPackets1_20_5.RESPAWN, wrapper -> {
+            final int dimensionId = wrapper.passthrough(Types.VAR_INT);
+            final String world = wrapper.passthrough(Types.STRING);
+            trackWorldDataByKey1_20_5(wrapper.user(), dimensionId, world); // Tracks world height and name for chunk data and entity (un)tracking
+        });
+    }
+
+    @Override
+    protected void registerRewrites() {
+        filter().handler((event, data) -> {
+            final EntityDataType type = data.dataType();
+            if (type == Types1_20_5.ENTITY_DATA_TYPES.wolfVariantType) {
+                final int variant = data.value();
+                data.setTypeAndValue(Types1_21.ENTITY_DATA_TYPES.wolfVariantType, Holder.of(variant));
+            } else if (type == Types1_20_5.ENTITY_DATA_TYPES.paintingVariantType) {
+                final int variant = data.value();
+                data.setTypeAndValue(Types1_21.ENTITY_DATA_TYPES.paintingVariantType, Holder.of(variant));
+            } else {
+                data.setDataType(Types1_21.ENTITY_DATA_TYPES.byId(type.typeId()));
+            }
+        });
+        registerEntityDataTypeHandler(
+            Types1_21.ENTITY_DATA_TYPES.itemType,
+            Types1_21.ENTITY_DATA_TYPES.blockStateType,
+            Types1_21.ENTITY_DATA_TYPES.optionalBlockStateType,
+            Types1_21.ENTITY_DATA_TYPES.particleType,
+            Types1_21.ENTITY_DATA_TYPES.particlesType,
+            Types1_21.ENTITY_DATA_TYPES.componentType,
+            Types1_21.ENTITY_DATA_TYPES.optionalComponentType
+        );
+        registerBlockStateHandler(EntityTypes1_20_5.ABSTRACT_MINECART, 11);
+    }
+
+    @Override
+    public EntityType typeFromId(final int type) {
+        return EntityTypes1_20_5.getTypeFromId(type);
+    }
+}

common/src/main/java/com/viaversion/viaversion/protocols/v1_20_5to1_21/storage/EfficiencyAttributeStorage.java

@@ -0,0 +1,141 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2024 ViaVersion and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.viaversion.viaversion.protocols.v1_20_5to1_21.storage;
+
+import com.viaversion.viaversion.api.connection.StorableObject;
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
+import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.Protocol1_20_5To1_21;
+import com.viaversion.viaversion.protocols.v1_20_5to1_21.packet.ClientboundPackets1_21;
+import java.util.List;
+
+public final class EfficiencyAttributeStorage implements StorableObject {
+
+    private static final EnchantAttributeModifier EFFICIENCY = new EnchantAttributeModifier("minecraft:enchantment.efficiency/mainhand", 19, 0, level -> (level * level) + 1);
+    private static final EnchantAttributeModifier SOUL_SPEED = new EnchantAttributeModifier("minecraft:enchantment.soul_speed", 21, 0.1, level -> 0.04D + ((level - 1) * 0.01D));
+    private static final EnchantAttributeModifier SWIFT_SNEAK = new EnchantAttributeModifier("minecraft:enchantment.swift_sneak", 25, 0.3, level -> level * 0.15D);
+    private static final EnchantAttributeModifier AQUA_AFFINITY = new EnchantAttributeModifier("minecraft:enchantment.aqua_affinity", 28, 0.2, level -> level * 4, (byte) 2);
+    private static final EnchantAttributeModifier DEPTH_STRIDER = new EnchantAttributeModifier("minecraft:enchantment.depth_strider", 30, 0, level -> level / 3D);
+    private static final ActiveEnchants DEFAULT = new ActiveEnchants(-1,
+        new ActiveEnchant(EFFICIENCY, 0),
+        new ActiveEnchant(SOUL_SPEED, 0),
+        new ActiveEnchant(SWIFT_SNEAK, 0),
+        new ActiveEnchant(AQUA_AFFINITY, 0),
+        new ActiveEnchant(DEPTH_STRIDER, 0)
+    );
+    private final Object lock = new Object();
+    private volatile boolean attributesSent = true;
+    private volatile boolean loginSent;
+    private ActiveEnchants activeEnchants = DEFAULT;
+
+    public void setEnchants(final int entityId, final UserConnection connection, final int efficiency, final int soulSpeed,
+                            final int swiftSneak, final int aquaAffinity, final int depthStrider) {
+        // Always called from the main thread
+        if (efficiency == activeEnchants.efficiency.level
+            && soulSpeed == activeEnchants.soulSpeed.level
+            && swiftSneak == activeEnchants.swiftSneak.level
+            && aquaAffinity == activeEnchants.aquaAffinity.level
+            && depthStrider == activeEnchants.depthStrider.level) {
+            return;
+        }
+
+        synchronized (lock) {
+            this.activeEnchants = new ActiveEnchants(entityId,
+                new ActiveEnchant(EFFICIENCY, efficiency),
+                new ActiveEnchant(SOUL_SPEED, soulSpeed),
+                new ActiveEnchant(SWIFT_SNEAK, swiftSneak),
+                new ActiveEnchant(AQUA_AFFINITY, aquaAffinity),
+                new ActiveEnchant(DEPTH_STRIDER, depthStrider)
+            );
+            this.attributesSent = false;
+        }
+        sendAttributesPacket(connection);
+    }
+
+    public ActiveEnchants activeEnchants() {
+        return activeEnchants;
+    }
+
+    public void onLoginSent(final UserConnection connection) {
+        // Always called from the netty thread
+        this.loginSent = true;
+        sendAttributesPacket(connection);
+    }
+
+    private void sendAttributesPacket(final UserConnection connection) {
+        final ActiveEnchants enchants;
+        synchronized (lock) {
+            // Older servers (and often Bungee) will send world state packets before sending the login packet
+            if (!loginSent || attributesSent) {
+                return;
+            }
+
+            enchants = this.activeEnchants;
+            attributesSent = true;
+        }
+
+        final PacketWrapper attributesPacket = PacketWrapper.create(ClientboundPackets1_21.UPDATE_ATTRIBUTES, connection);
+        attributesPacket.write(Types.VAR_INT, enchants.entityId());
+
+        final List<ActiveEnchant> list = List.of(
+            enchants.efficiency(),
+            enchants.soulSpeed(),
+            enchants.swiftSneak(),
+            enchants.aquaAffinity(),
+            enchants.depthStrider()
+        );
+        attributesPacket.write(Types.VAR_INT, list.size());
+        for (final ActiveEnchant enchant : list) {
+            final EnchantAttributeModifier modifier = enchant.modifier;
+            attributesPacket.write(Types.VAR_INT, modifier.attributeId);
+            attributesPacket.write(Types.DOUBLE, modifier.baseValue);
+
+            if (enchant.level > 0) {
+                attributesPacket.write(Types.VAR_INT, 1); // Modifiers
+                attributesPacket.write(Types.STRING, modifier.key);
+                attributesPacket.write(Types.DOUBLE, enchant.modifier.modifierFunction.get(enchant.level));
+                attributesPacket.write(Types.BYTE, modifier.operation);
+            } else {
+                attributesPacket.write(Types.VAR_INT, 0); // Modifiers
+            }
+        }
+
+        attributesPacket.scheduleSend(Protocol1_20_5To1_21.class);
+    }
+
+    public record ActiveEnchants(int entityId, ActiveEnchant efficiency, ActiveEnchant soulSpeed,
+                                 ActiveEnchant swiftSneak, ActiveEnchant aquaAffinity, ActiveEnchant depthStrider) {
+    }
+
+    public record ActiveEnchant(EnchantAttributeModifier modifier, int level) {
+    }
+
+    public record EnchantAttributeModifier(String key, int attributeId, double baseValue, LevelToModifier modifierFunction, byte operation) {
+
+        private EnchantAttributeModifier(String key, int attributeId, double baseValue, LevelToModifier modifierFunction) {
+            this(key, attributeId, baseValue, modifierFunction, (byte) 0);
+        }
+    }
+
+    @FunctionalInterface
+    private interface LevelToModifier {
+
+        double get(int level);
+    }
+}

common/src/main/java/com/viaversion/viaversion/protocols/v1_8to1_9/Protocol1_8To1_9.java

@@ -18,10 +18,8 @@
 package com.viaversion.viaversion.protocols.v1_8to1_9;
 
 import com.google.gson.JsonElement;
-import com.viaversion.viaversion.api.Via;
 import com.viaversion.viaversion.api.connection.UserConnection;
 import com.viaversion.viaversion.api.minecraft.ClientWorld;
-import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.platform.providers.ViaProviders;
 import com.viaversion.viaversion.api.protocol.AbstractProtocol;
 import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
@@ -68,10 +66,6 @@ public class Protocol1_8To1_9 extends AbstractProtocol<ClientboundPackets1_8, Cl
         super(ClientboundPackets1_8.class, ClientboundPackets1_9.class, ServerboundPackets1_8.class, ServerboundPackets1_9.class);
     }
 
-    public static Item getHandItem(final UserConnection info) {
-        return Via.getManager().getProviders().get(HandItemProvider.class).getHandItem(info);
-    }
-
     public static boolean isSword(int id) {
         return switch (id) {
             case 267, // Iron sword

common/src/main/java/com/viaversion/viaversion/protocols/v1_8to1_9/provider/HandItemProvider.java

@@ -18,12 +18,13 @@
 package com.viaversion.viaversion.protocols.v1_8to1_9.provider;
 
 import com.viaversion.viaversion.api.connection.UserConnection;
-import com.viaversion.viaversion.api.minecraft.item.DataItem;
 import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.platform.providers.Provider;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 public class HandItemProvider implements Provider {
-    public Item getHandItem(final UserConnection info) {
-        return new DataItem(0, (byte) 0, (short) 0, null);
+
+    public @Nullable Item getHandItem(final UserConnection connection) {
+        return null;
     }
 }

common/src/main/java/com/viaversion/viaversion/protocols/v1_8to1_9/rewriter/ItemPacketRewriter1_9.java

@@ -43,7 +43,7 @@ import org.checkerframework.checker.nullness.qual.Nullable;
 public class ItemPacketRewriter1_9 extends ItemRewriter<ClientboundPackets1_8, ServerboundPackets1_9, Protocol1_8To1_9> {
 
     public ItemPacketRewriter1_9(final Protocol1_8To1_9 protocol) {
-        super(protocol, null, null);
+        super(protocol, Types.ITEM1_8, Types.ITEM1_8_SHORT_ARRAY);
     }
 
     @Override
@@ -418,6 +418,8 @@ public class ItemPacketRewriter1_9 extends ItemRewriter<ClientboundPackets1_8, S
             }
 
             ListTag<StringTag> pages = tag.getListTag("pages", StringTag.class);
+            tag.put(nbtTagName("pages"), pages == null ? new ListTag<>(StringTag.class) : pages.copy());
+
             if (pages == null) {
                 pages = new ListTag<>(Collections.singletonList(new StringTag(ComponentUtil.emptyJsonComponent().toString())));
                 tag.put("pages", pages);
@@ -481,6 +483,32 @@ public class ItemPacketRewriter1_9 extends ItemRewriter<ClientboundPackets1_8, S
             item.setTag(tag);
             item.setData((short) data);
         }
+        if (item.identifier() == 387) { // WRITTEN_BOOK
+            CompoundTag tag = item.tag();
+            if (tag != null) {
+                // Prefer saved pages since they are more likely to be accurate
+                ListTag<StringTag> backup = tag.removeUnchecked(nbtTagName("pages"));
+                if (backup != null) {
+                    if (!backup.isEmpty()) {
+                        tag.put("pages", backup);
+                    } else {
+                        tag.remove("pages");
+                        if (tag.isEmpty()) {
+                            item.setTag(null);
+                        }
+                    }
+                } else {
+                    // Fallback to normal pages tag
+                    ListTag<StringTag> pages = tag.getListTag("pages", StringTag.class);
+                    if (pages != null) {
+                        for (int i = 0; i < pages.size(); i++) {
+                            final StringTag page = pages.get(i);
+                            page.setValue(ComponentUtil.convertJsonOrEmpty(page.getValue(), SerializerVersion.V1_9, SerializerVersion.V1_8).toString());
+                        }
+                    }
+                }
+            }
+        }
 
         boolean newItem = item.identifier() >= 198 && item.identifier() <= 212;
         newItem |= item.identifier() == 397 && item.data() == 5;

common/src/main/java/com/viaversion/viaversion/protocols/v1_8to1_9/rewriter/PlayerPacketRewriter1_9.java

@@ -40,7 +40,6 @@ import com.viaversion.viaversion.protocols.v1_8to1_9.storage.ClientChunks;
 import com.viaversion.viaversion.protocols.v1_8to1_9.storage.EntityTracker1_9;
 import com.viaversion.viaversion.protocols.v1_8to1_9.storage.MovementTracker;
 import com.viaversion.viaversion.util.ComponentUtil;
-import com.viaversion.viaversion.util.SerializerVersion;
 
 public class PlayerPacketRewriter1_9 {
     public static void register(Protocol1_8To1_9 protocol) {
@@ -197,7 +196,9 @@ public class PlayerPacketRewriter1_9 {
 
                 handler(wrapper -> {
                     EntityTracker1_9 tracker = wrapper.user().getEntityTracker(Protocol1_8To1_9.class);
-                    tracker.setGameMode(GameMode.getById(wrapper.get(Types.UNSIGNED_BYTE, 0))); //Set player gamemode
+                    short gamemodeId = wrapper.get(Types.UNSIGNED_BYTE, 0);
+                    gamemodeId &= -9; // remove the hardcore mode flag
+                    tracker.setGameMode(GameMode.getById(gamemodeId)); //Set player gamemode
                 });
 
                 // Track player's dimension
@@ -276,33 +277,11 @@ public class PlayerPacketRewriter1_9 {
             public void register() {
                 map(Types.STRING); // 0 - Channel Name
                 handlerSoftFail(wrapper -> {
-                    String name = wrapper.get(Types.STRING, 0);
+                    final String name = wrapper.get(Types.STRING, 0);
                     if (name.equals("MC|BOpen")) {
                         wrapper.write(Types.VAR_INT, 0);
                     } else if (name.equals("MC|TrList")) {
-                        wrapper.passthrough(Types.INT); // ID
-
-                        Short size = wrapper.passthrough(Types.UNSIGNED_BYTE);
-
-                        for (int i = 0; i < size; ++i) {
-                            Item item1 = wrapper.passthrough(Types.ITEM1_8);
-                            protocol.getItemRewriter().handleItemToClient(wrapper.user(), item1);
-
-                            Item item2 = wrapper.passthrough(Types.ITEM1_8);
-                            protocol.getItemRewriter().handleItemToClient(wrapper.user(), item2);
-
-                            boolean present = wrapper.passthrough(Types.BOOLEAN);
-
-                            if (present) {
-                                Item item3 = wrapper.passthrough(Types.ITEM1_8);
-                                protocol.getItemRewriter().handleItemToClient(wrapper.user(), item3);
-                            }
-
-                            wrapper.passthrough(Types.BOOLEAN);
-
-                            wrapper.passthrough(Types.INT);
-                            wrapper.passthrough(Types.INT);
-                        }
+                        protocol.getItemRewriter().handleTradeList(wrapper);
                     }
                 });
             }
@@ -432,7 +411,7 @@ public class PlayerPacketRewriter1_9 {
                                 final StringTag pageTag = pages.get(i);
                                 final String value = pageTag.getValue();
 
-                                pageTag.setValue(ComponentUtil.convertJson(value, SerializerVersion.V1_9, SerializerVersion.V1_8).toString());
+                                pageTag.setValue(ComponentUtil.plainToJson(value).toString());
                             }
                         }
                     }

common/src/main/java/com/viaversion/viaversion/protocols/v1_8to1_9/rewriter/WorldPacketRewriter1_9.java

@@ -44,6 +44,7 @@ import com.viaversion.viaversion.protocols.v1_8to1_9.packet.ClientboundPackets1_
 import com.viaversion.viaversion.protocols.v1_8to1_9.packet.ServerboundPackets1_8;
 import com.viaversion.viaversion.protocols.v1_8to1_9.packet.ServerboundPackets1_9;
 import com.viaversion.viaversion.protocols.v1_8to1_9.provider.CommandBlockProvider;
+import com.viaversion.viaversion.protocols.v1_8to1_9.provider.HandItemProvider;
 import com.viaversion.viaversion.protocols.v1_8to1_9.storage.ClientChunks;
 import com.viaversion.viaversion.protocols.v1_8to1_9.storage.EntityTracker1_9;
 import com.viaversion.viaversion.util.ComponentUtil;
@@ -293,7 +294,7 @@ public class WorldPacketRewriter1_9 {
             wrapper.write(Types.BLOCK_POSITION1_8, new BlockPosition(-1, -1, -1));
             wrapper.write(Types.UNSIGNED_BYTE, (short) 255);
             // Write item in hand
-            Item item = Protocol1_8To1_9.getHandItem(wrapper.user());
+            Item item = Via.getManager().getProviders().get(HandItemProvider.class).getHandItem(wrapper.user());
             // Blocking patch
             if (Via.getConfig().isShieldBlocking()) {
                 EntityTracker1_9 tracker = wrapper.user().getEntityTracker(Protocol1_8To1_9.class);
@@ -350,7 +351,7 @@ public class WorldPacketRewriter1_9 {
                     if (hand != 0) wrapper.cancel();
                 });
                 handler(wrapper -> {
-                    Item item = Protocol1_8To1_9.getHandItem(wrapper.user());
+                    Item item = Via.getManager().getProviders().get(HandItemProvider.class).getHandItem(wrapper.user());
                     wrapper.write(Types.ITEM1_8, item); // 3 - Item
                 });
                 map(Types.UNSIGNED_BYTE); // 4 - X

common/src/main/java/com/viaversion/viaversion/protocols/v1_9_3to1_10/rewriter/ItemPacketRewriter1_10.java

@@ -28,7 +28,7 @@ import com.viaversion.viaversion.rewriter.ItemRewriter;
 public class ItemPacketRewriter1_10 extends ItemRewriter<ClientboundPackets1_9_3, ServerboundPackets1_9_3, Protocol1_9_3To1_10> {
 
     public ItemPacketRewriter1_10(Protocol1_9_3To1_10 protocol) {
-        super(protocol, Types.ITEM1_8, null);
+        super(protocol, Types.ITEM1_8, Types.ITEM1_8_SHORT_ARRAY);
     }
 
     @Override

common/src/main/java/com/viaversion/viaversion/rewriter/AttributeRewriter.java

@@ -28,23 +28,41 @@ public class AttributeRewriter<C extends ClientboundPacketType> {
         this.protocol = protocol;
     }
 
-    public void register1_20_5(C packetType) {
+    public void register1_21(C packetType) {
         protocol.registerClientbound(packetType, wrapper -> {
             wrapper.passthrough(Types.VAR_INT); // Entity ID
 
             final int size = wrapper.passthrough(Types.VAR_INT);
+            int newSize = size;
             for (int i = 0; i < size; i++) {
                 final int attributeId = wrapper.read(Types.VAR_INT);
-                wrapper.write(Types.VAR_INT, protocol.getMappingData().getNewAttributeId(attributeId));
+                final int mappedId = protocol.getMappingData().getNewAttributeId(attributeId);
+                if (mappedId == -1) {
+                    newSize--;
 
+                    wrapper.read(Types.DOUBLE); // Base
+                    final int modifierSize = wrapper.read(Types.VAR_INT);
+                    for (int j = 0; j < modifierSize; j++) {
+                        wrapper.read(Types.STRING); // ID
+                        wrapper.read(Types.DOUBLE); // Amount
+                        wrapper.read(Types.BYTE); // Operation
+                    }
+                    continue;
+                }
+
+                wrapper.write(Types.VAR_INT, mappedId);
                 wrapper.passthrough(Types.DOUBLE); // Base
                 final int modifierSize = wrapper.passthrough(Types.VAR_INT);
                 for (int j = 0; j < modifierSize; j++) {
-                    wrapper.passthrough(Types.UUID); // ID
+                    wrapper.passthrough(Types.STRING); // ID
                     wrapper.passthrough(Types.DOUBLE); // Amount
                     wrapper.passthrough(Types.BYTE); // Operation
                 }
             }
+
+            if (size != newSize) {
+                wrapper.set(Types.VAR_INT, 1, newSize);
+            }
         });
     }
 }

common/src/main/java/com/viaversion/viaversion/rewriter/BlockRewriter.java

@@ -20,6 +20,7 @@ package com.viaversion.viaversion.rewriter;
 import com.google.common.base.Preconditions;
 import com.viaversion.nbt.tag.CompoundTag;
 import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.data.MappingData;
 import com.viaversion.viaversion.api.data.Mappings;
 import com.viaversion.viaversion.api.data.entity.EntityTracker;
 import com.viaversion.viaversion.api.minecraft.BlockChangeRecord;
@@ -154,25 +155,26 @@ public class BlockRewriter<C extends ClientboundPacketType> {
     }
 
     public void registerLevelEvent(C packetType, int playRecordId, int blockBreakId) {
-        protocol.registerClientbound(packetType, new PacketHandlers() {
-            @Override
-            public void register() {
-                map(Types.INT); // Effect Id
-                map(positionType); // Location
-                map(Types.INT); // Data
-                handler(wrapper -> {
-                    int id = wrapper.get(Types.INT, 0);
-                    int data = wrapper.get(Types.INT, 1);
-                    if (id == playRecordId && protocol.getMappingData().getItemMappings() != null) {
-                        wrapper.set(Types.INT, 1, protocol.getMappingData().getNewItemId(data));
-                    } else if (id == blockBreakId && protocol.getMappingData().getBlockStateMappings() != null) {
-                        wrapper.set(Types.INT, 1, protocol.getMappingData().getNewBlockStateId(data));
-                    }
-                });
+        protocol.registerClientbound(packetType, wrapper -> {
+            final int id = wrapper.passthrough(Types.INT);
+            wrapper.passthrough(positionType);
+
+            final int data = wrapper.read(Types.INT);
+            final MappingData mappingData = protocol.getMappingData();
+            if (playRecordId != -1 && id == playRecordId && mappingData.getItemMappings() != null) {
+                wrapper.write(Types.INT, mappingData.getNewItemId(data));
+            } else if (id == blockBreakId && mappingData.getBlockStateMappings() != null) {
+                wrapper.write(Types.INT, mappingData.getNewBlockStateId(data));
+            } else {
+                wrapper.write(Types.INT, data);
             }
         });
     }
 
+    public void registerLevelEvent1_21(C packetType, int blockBreakId) {
+        registerLevelEvent(packetType, -1, blockBreakId);
+    }
+
     public void registerLevelChunk(C packetType, Type<Chunk> chunkType, Type<Chunk> newChunkType) {
         registerLevelChunk(packetType, chunkType, newChunkType, null);
     }

common/src/main/java/com/viaversion/viaversion/rewriter/ComponentRewriter.java

@@ -36,13 +36,15 @@ import com.viaversion.viaversion.api.protocol.packet.State;
 import com.viaversion.viaversion.api.protocol.remapper.PacketHandlers;
 import com.viaversion.viaversion.api.type.Types;
 import com.viaversion.viaversion.protocols.base.ClientboundLoginPackets;
+import com.viaversion.viaversion.util.ComponentUtil;
+import com.viaversion.viaversion.util.SerializerVersion;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
- * Handles json chat components, containing methods to override certain parts of the handling.
+ * Handles json and tag components, containing methods to override certain parts of the handling.
  * Also contains methods to register a few of the packets using components.
  */
-public class ComponentRewriter<C extends ClientboundPacketType> {
+public class ComponentRewriter<C extends ClientboundPacketType> implements com.viaversion.viaversion.api.rewriter.ComponentRewriter {
     protected final Protocol<C, ?, ?, ?> protocol;
     protected final ReadType type;
 
@@ -249,6 +251,7 @@ public class ComponentRewriter<C extends ClientboundPacketType> {
     // -----------------------------------------------------------------------
     // Tag methods
 
+    @Override
     public void processTag(final UserConnection connection, @Nullable final Tag tag) {
         if (tag == null) {
             return;
@@ -309,6 +312,48 @@ public class ComponentRewriter<C extends ClientboundPacketType> {
             if (contents != null) {
                 processTag(connection, contents.get("name"));
             }
+        } else if (action.equals("show_item")) {
+            convertLegacyContents(hoverEventTag);
+
+            final CompoundTag contentsTag = hoverEventTag.getCompoundTag("contents");
+            if (contentsTag == null) {
+                return;
+            }
+
+            final CompoundTag componentsTag = contentsTag.getCompoundTag("components");
+            if (componentsTag != null) {
+                handleShowItem(connection, componentsTag);
+            }
+        }
+    }
+
+    protected void handleShowItem(final UserConnection connection, final CompoundTag componentsTag) {
+        // To override if needed
+    }
+
+    protected SerializerVersion inputSerializerVersion() {
+        return null;
+    }
+
+    protected SerializerVersion outputSerializerVersion() {
+        return null;
+    }
+
+    private void convertLegacyContents(final CompoundTag hoverEvent) {
+        if (inputSerializerVersion() == null || outputSerializerVersion() == null) {
+            return;
+        }
+
+        final Tag valueTag = hoverEvent.remove("value");
+        if (valueTag != null) {
+            final CompoundTag tag = ComponentUtil.deserializeShowItem(valueTag, inputSerializerVersion());
+            final CompoundTag contentsTag = new CompoundTag();
+            contentsTag.put("id", tag.getStringTag("id"));
+            contentsTag.put("count", tag.getIntTag("count"));
+            if (tag.get("tag") instanceof CompoundTag) {
+                contentsTag.putString("tag", outputSerializerVersion().toSNBT(tag.getCompoundTag("tag")));
+            }
+            hoverEvent.put("contents", contentsTag);
         }
     }
 

common/src/main/java/com/viaversion/viaversion/rewriter/EntityRewriter.java

@@ -21,6 +21,7 @@ import com.google.common.base.Preconditions;
 import com.viaversion.nbt.tag.CompoundTag;
 import com.viaversion.nbt.tag.ListTag;
 import com.viaversion.nbt.tag.NumberTag;
+import com.viaversion.nbt.tag.Tag;
 import com.viaversion.viaversion.api.Via;
 import com.viaversion.viaversion.api.connection.UserConnection;
 import com.viaversion.viaversion.api.data.Int2IntMapMappings;
@@ -32,9 +33,9 @@ import com.viaversion.viaversion.api.data.entity.TrackedEntity;
 import com.viaversion.viaversion.api.minecraft.Particle;
 import com.viaversion.viaversion.api.minecraft.RegistryEntry;
 import com.viaversion.viaversion.api.minecraft.entities.EntityType;
-import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.minecraft.entitydata.EntityData;
 import com.viaversion.viaversion.api.minecraft.entitydata.EntityDataType;
+import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.protocol.Protocol;
 import com.viaversion.viaversion.api.protocol.packet.ClientboundPacketType;
 import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
@@ -51,6 +52,7 @@ import com.viaversion.viaversion.rewriter.entitydata.EntityDataHandlerEventImpl;
 import com.viaversion.viaversion.util.Key;
 import com.viaversion.viaversion.util.TagUtil;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Comparator;
 import java.util.HashMap;
 import java.util.List;
@@ -190,6 +192,10 @@ public abstract class EntityRewriter<C extends ClientboundPacketType, T extends
         registerEntityDataTypeHandler(itemType, null, blockStateType, particleType, null);
     }
 
+    public void registerEntityDataTypeHandler(@Nullable EntityDataType itemType, @Nullable EntityDataType blockStateType, @Nullable EntityDataType optionalBlockStateType, @Nullable EntityDataType particleType, @Nullable EntityDataType particlesType) {
+        registerEntityDataTypeHandler(itemType, blockStateType, optionalBlockStateType, particleType, particlesType, null, null);
+    }
+
     /**
      * Registers an entity data handler to rewrite, item, block, and particle ids stored in entity data.
      *
@@ -198,8 +204,12 @@ public abstract class EntityRewriter<C extends ClientboundPacketType, T extends
      * @param optionalBlockStateType optional block state data type if needed
      * @param particleType           particle data type if needed
      * @param particlesType          particles data type if needed
+     * @param componentType          component data type if needed
+     * @param optionalComponentType  optional component data type if needed
      */
-    public void registerEntityDataTypeHandler(@Nullable EntityDataType itemType, @Nullable EntityDataType blockStateType, @Nullable EntityDataType optionalBlockStateType, @Nullable EntityDataType particleType, @Nullable EntityDataType particlesType) {
+    public void registerEntityDataTypeHandler(@Nullable EntityDataType itemType, @Nullable EntityDataType blockStateType, @Nullable EntityDataType optionalBlockStateType,
+                                              @Nullable EntityDataType particleType, @Nullable EntityDataType particlesType,
+                                              @Nullable EntityDataType componentType, @Nullable EntityDataType optionalComponentType) {
         filter().handler((event, data) -> {
             final EntityDataType type = data.dataType();
             if (type == itemType) {
@@ -219,6 +229,9 @@ public abstract class EntityRewriter<C extends ClientboundPacketType, T extends
                 for (final Particle particle : particles) {
                     rewriteParticle(event.user(), particle);
                 }
+            } else if (type == componentType || type == optionalComponentType) {
+                final Tag component = data.value();
+                protocol.getComponentRewriter().processTag(event.user(), component);
             }
         });
     }
@@ -445,27 +458,32 @@ public abstract class EntityRewriter<C extends ClientboundPacketType, T extends
 
     public PacketHandler worldDataTrackerHandlerByKey1_20_5(final int dimensionIdIndex) {
         return wrapper -> {
-            EntityTracker tracker = tracker(wrapper.user());
             int dimensionId = wrapper.get(Types.VAR_INT, dimensionIdIndex);
-            DimensionData dimensionData = tracker.dimensionData(dimensionId);
-            if (dimensionData == null) {
-                protocol.getLogger().severe("Dimension data missing for dimension: " + dimensionId + ", falling back to overworld");
-                dimensionData = tracker.dimensionData("minecraft:overworld");
-                Preconditions.checkNotNull(dimensionData, "Overworld data missing");
-            }
-
-            tracker.setCurrentWorldSectionHeight(dimensionData.height() >> 4);
-            tracker.setCurrentMinY(dimensionData.minY());
-
             String world = wrapper.get(Types.STRING, 0);
-            if (tracker.currentWorld() != null && !tracker.currentWorld().equals(world)) {
-                tracker.clearEntities();
-                tracker.trackClientEntity();
-            }
-            tracker.setCurrentWorld(world);
+            trackWorldDataByKey1_20_5(wrapper.user(), dimensionId, world);
         };
     }
 
+    public void trackWorldDataByKey1_20_5(final UserConnection connection, final int dimensionId, final String world) {
+        // Track world height for use in chunk data
+        EntityTracker tracker = tracker(connection);
+        DimensionData dimensionData = tracker.dimensionData(dimensionId);
+        if (dimensionData == null) {
+            protocol.getLogger().severe("Dimension data missing for dimension: " + dimensionId + ", falling back to overworld");
+            dimensionData = tracker.dimensionData("overworld");
+            Preconditions.checkNotNull(dimensionData, "Overworld data missing");
+        }
+        tracker.setCurrentWorldSectionHeight(dimensionData.height() >> 4);
+        tracker.setCurrentMinY(dimensionData.minY());
+
+        // Clear entities if the world changes
+        if (tracker.currentWorld() != null && !tracker.currentWorld().equals(world)) {
+            tracker.clearEntities();
+            tracker.trackClientEntity();
+        }
+        tracker.setCurrentWorld(world);
+    }
+
     public PacketHandler biomeSizeTracker() {
         return wrapper -> trackBiomeSize(wrapper.user(), wrapper.get(Types.NAMED_COMPOUND_TAG, 0));
     }
@@ -502,22 +520,21 @@ public abstract class EntityRewriter<C extends ClientboundPacketType, T extends
         tracker(connection).setDimensions(dimensionDataMap);
     }
 
-    public PacketHandler registryDataHandler1_20_5() {
-        return wrapper -> {
-            final String registryKey = Key.stripMinecraftNamespace(wrapper.get(Types.STRING, 0));
-            if (registryKey.equals("worldgen/biome")) {
-                final RegistryEntry[] entries = wrapper.get(Types.REGISTRY_ENTRY_ARRAY, 0);
-                tracker(wrapper.user()).setBiomesSent(entries.length);
-            } else if (registryKey.equals("dimension_type")) {
-                final RegistryEntry[] entries = wrapper.get(Types.REGISTRY_ENTRY_ARRAY, 0);
-                final Map<String, DimensionData> dimensionDataMap = new HashMap<>(entries.length);
-                for (int i = 0; i < entries.length; i++) {
-                    final RegistryEntry entry = entries[i];
-                    dimensionDataMap.put(Key.stripMinecraftNamespace(entry.key()), new DimensionDataImpl(i, (CompoundTag) entry.tag()));
-                }
-                tracker(wrapper.user()).setDimensions(dimensionDataMap);
+    public void handleRegistryData1_20_5(final UserConnection connection, final String registryKey, final RegistryEntry[] entries) {
+        if (registryKey.equals("worldgen/biome")) {
+            tracker(connection).setBiomesSent(entries.length);
+        } else if (registryKey.equals("dimension_type")) {
+            final Map<String, DimensionData> dimensionDataMap = new HashMap<>(entries.length);
+            for (int i = 0; i < entries.length; i++) {
+                final RegistryEntry entry = entries[i];
+                final String key = Key.stripMinecraftNamespace(entry.key());
+                final DimensionData dimensionData = entry.tag() != null
+                    ? new DimensionDataImpl(i, (CompoundTag) entry.tag())
+                    : DimensionDataImpl.withDefaultsFor(key, i);
+                dimensionDataMap.put(key, dimensionData);
             }
-        };
+            tracker(connection).setDimensions(dimensionDataMap);
+        }
     }
 
     // ---------------------------------------------------------------------------
@@ -579,6 +596,13 @@ public abstract class EntityRewriter<C extends ClientboundPacketType, T extends
 
     // ---------------------------------------------------------------------------
 
+    public RegistryEntry[] addRegistryEntries(final RegistryEntry[] entries, final RegistryEntry... toAdd) {
+        final int length = entries.length;
+        final RegistryEntry[] newEntries = Arrays.copyOf(entries, length + toAdd.length);
+        System.arraycopy(toAdd, 0, newEntries, length, toAdd.length);
+        return newEntries;
+    }
+
     public void rewriteParticle(UserConnection connection, Particle particle) {
         ParticleMappings mappings = protocol.getMappingData().getParticleMappings();
         int id = particle.id();

common/src/main/java/com/viaversion/viaversion/rewriter/ItemRewriter.java

@@ -17,6 +17,7 @@
  */
 package com.viaversion.viaversion.rewriter;
 
+import com.viaversion.nbt.tag.Tag;
 import com.viaversion.viaversion.api.connection.UserConnection;
 import com.viaversion.viaversion.api.data.Mappings;
 import com.viaversion.viaversion.api.data.ParticleMappings;
@@ -28,6 +29,7 @@ import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
 import com.viaversion.viaversion.api.protocol.packet.ServerboundPacketType;
 import com.viaversion.viaversion.api.protocol.remapper.PacketHandler;
 import com.viaversion.viaversion.api.protocol.remapper.PacketHandlers;
+import com.viaversion.viaversion.api.rewriter.ComponentRewriter;
 import com.viaversion.viaversion.api.rewriter.RewriterBase;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
@@ -110,20 +112,22 @@ public class ItemRewriter<C extends ClientboundPacketType, S extends Serverbound
             @Override
             public void register() {
                 map(Types.VAR_INT); // Container id
-                handler(wrapper -> {
-                    final int windowType = wrapper.read(Types.VAR_INT);
-                    final int mappedId = protocol.getMappingData().getMenuMappings().getNewId(windowType);
-                    if (mappedId == -1) {
-                        wrapper.cancel();
-                        return;
-                    }
-
-                    wrapper.write(Types.VAR_INT, mappedId);
-                });
+                handler(wrapper -> handleMenuType(wrapper));
             }
         });
     }
 
+    public void handleMenuType(final PacketWrapper wrapper) {
+        final int windowType = wrapper.read(Types.VAR_INT);
+        final int mappedId = protocol.getMappingData().getMenuMappings().getNewId(windowType);
+        if (mappedId == -1) {
+            wrapper.cancel();
+            return;
+        }
+
+        wrapper.write(Types.VAR_INT, mappedId);
+    }
+
     public void registerSetSlot(C packetType) {
         protocol.registerClientbound(packetType, new PacketHandlers() {
             @Override
@@ -234,6 +238,41 @@ public class ItemRewriter<C extends ClientboundPacketType, S extends Serverbound
         });
     }
 
+
+    public void registerCustomPayloadTradeList(C packetType) {
+        protocol.registerClientbound(packetType, new PacketHandlers() {
+            @Override
+            protected void register() {
+                map(Types.STRING); // 0 - Channel
+                handlerSoftFail(wrapper -> {
+                    final String channel = wrapper.get(Types.STRING, 0);
+                    if (channel.equals("MC|TrList")) {
+                        handleTradeList(wrapper);
+                    }
+                });
+            }
+        });
+    }
+
+    public void handleTradeList(final PacketWrapper wrapper) {
+        wrapper.passthrough(Types.INT); // Window ID
+
+        final int size = wrapper.passthrough(Types.UNSIGNED_BYTE);
+        for (int i = 0; i < size; i++) {
+            handleClientboundItem(wrapper); // Input Item
+            handleClientboundItem(wrapper); // Output Item
+
+            if (wrapper.passthrough(Types.BOOLEAN)) {
+                handleClientboundItem(wrapper); // Second Item
+            }
+
+            wrapper.passthrough(Types.BOOLEAN); // Trade disabled
+            wrapper.passthrough(Types.INT); // Number of tools uses
+            wrapper.passthrough(Types.INT); // Maximum number of trade uses
+        }
+    }
+
+
     // 1.14.4+
     public void registerMerchantOffers(C packetType) {
         protocol.registerClientbound(packetType, wrapper -> {
@@ -346,15 +385,7 @@ public class ItemRewriter<C extends ClientboundPacketType, S extends Serverbound
         });
     }
 
-    public void registerAdvancements1_20_2(C packetType) {
-        registerAdvancements1_20_2(packetType, Types.COMPONENT);
-    }
-
     public void registerAdvancements1_20_3(C packetType) {
-        registerAdvancements1_20_2(packetType, Types.TAG);
-    }
-
-    private void registerAdvancements1_20_2(C packetType, Type<?> componentType) {
         protocol.registerClientbound(packetType, wrapper -> {
             wrapper.passthrough(Types.BOOLEAN); // Reset/clear
             int size = wrapper.passthrough(Types.VAR_INT); // Mapping size
@@ -364,8 +395,14 @@ public class ItemRewriter<C extends ClientboundPacketType, S extends Serverbound
 
                 // Display data
                 if (wrapper.passthrough(Types.BOOLEAN)) {
-                    wrapper.passthrough(componentType); // Title
-                    wrapper.passthrough(componentType); // Description
+                    final Tag title = wrapper.passthrough(Types.TAG);
+                    final Tag description = wrapper.passthrough(Types.TAG);
+                    final ComponentRewriter componentRewriter = protocol.getComponentRewriter();
+                    if (componentRewriter != null) {
+                        componentRewriter.processTag(wrapper.user(), title);
+                        componentRewriter.processTag(wrapper.user(), description);
+                    }
+
                     handleClientboundItem(wrapper); // Icon
                     wrapper.passthrough(Types.VAR_INT); // Frame type
                     int flags = wrapper.passthrough(Types.INT); // Flags
@@ -469,7 +506,7 @@ public class ItemRewriter<C extends ClientboundPacketType, S extends Serverbound
     }
 
     public void registerExplosion(C packetType, Type<Particle> unmappedParticleType, Type<Particle> mappedParticleType) {
-        final SoundRewriter<C> cSoundRewriter = new SoundRewriter<>(protocol);
+        final SoundRewriter<C> soundRewriter = new SoundRewriter<>(protocol);
         protocol.registerClientbound(packetType, wrapper -> {
             wrapper.passthrough(Types.DOUBLE); // X
             wrapper.passthrough(Types.DOUBLE); // Y
@@ -493,7 +530,7 @@ public class ItemRewriter<C extends ClientboundPacketType, S extends Serverbound
             rewriteParticle(wrapper.user(), smallExplosionParticle);
             rewriteParticle(wrapper.user(), largeExplosionParticle);
 
-            cSoundRewriter.soundHolderHandler().handle(wrapper);
+            soundRewriter.soundHolderHandler().handle(wrapper);
         });
     }
 

common/src/main/java/com/viaversion/viaversion/rewriter/RecipeRewriter.java

@@ -56,7 +56,7 @@ public class RecipeRewriter<C extends ClientboundPacketType> {
     }
 
     public void handleRecipeType(PacketWrapper wrapper, String type) {
-        RecipeConsumer handler = recipeHandlers.get(type);
+        RecipeConsumer handler = recipeHandlers.get(Key.stripMinecraftNamespace(type));
         if (handler != null) {
             handler.accept(wrapper);
         }
@@ -73,7 +73,7 @@ public class RecipeRewriter<C extends ClientboundPacketType> {
             for (int i = 0; i < size; i++) {
                 String type = wrapper.passthrough(Types.STRING);
                 wrapper.passthrough(Types.STRING); // Recipe Identifier
-                handleRecipeType(wrapper, Key.stripMinecraftNamespace(type));
+                handleRecipeType(wrapper, type);
             }
         });
     }
@@ -82,7 +82,7 @@ public class RecipeRewriter<C extends ClientboundPacketType> {
         protocol.registerClientbound(packetType, wrapper -> {
             int size = wrapper.passthrough(Types.VAR_INT);
             for (int i = 0; i < size; i++) {
-                wrapper.passthrough(Types.STRING);// Recipe Identifier
+                wrapper.passthrough(Types.STRING); // Recipe Identifier
 
                 final int typeId = wrapper.passthrough(Types.VAR_INT);
                 final String type = protocol.getMappingData().getRecipeSerializerMappings().identifier(typeId);

common/src/main/java/com/viaversion/viaversion/rewriter/StructuredItemRewriter.java

@@ -17,13 +17,23 @@
  */
 package com.viaversion.viaversion.rewriter;
 
+import com.viaversion.nbt.tag.CompoundTag;
+import com.viaversion.nbt.tag.Tag;
 import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.data.FullMappings;
 import com.viaversion.viaversion.api.data.MappingData;
+import com.viaversion.viaversion.api.minecraft.data.StructuredData;
+import com.viaversion.viaversion.api.minecraft.data.StructuredDataContainer;
+import com.viaversion.viaversion.api.minecraft.data.StructuredDataKey;
 import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.protocol.Protocol;
 import com.viaversion.viaversion.api.protocol.packet.ClientboundPacketType;
 import com.viaversion.viaversion.api.protocol.packet.ServerboundPacketType;
+import com.viaversion.viaversion.api.rewriter.ComponentRewriter;
 import com.viaversion.viaversion.api.type.Type;
+import it.unimi.dsi.fastutil.ints.Int2IntFunction;
+import java.util.Map;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 public class StructuredItemRewriter<C extends ClientboundPacketType, S extends ServerboundPacketType,
     T extends Protocol<C, ?, ?, S>> extends ItemRewriter<C, S, T> {
@@ -43,14 +53,40 @@ public class StructuredItemRewriter<C extends ClientboundPacketType, S extends S
         }
 
         final MappingData mappingData = protocol.getMappingData();
+        final StructuredDataContainer dataContainer = item.dataContainer();
         if (mappingData != null) {
             if (mappingData.getItemMappings() != null) {
                 item.setIdentifier(mappingData.getNewItemId(item.identifier()));
             }
-            if (mappingData.getDataComponentSerializerMappings() != null) {
-                item.dataContainer().setIdLookup(protocol, true);
+
+            final FullMappings dataComponentMappings = mappingData.getDataComponentSerializerMappings();
+            if (dataComponentMappings != null) {
+                dataContainer.setIdLookup(protocol, true);
+                dataContainer.updateIds(protocol, dataComponentMappings::getNewId);
             }
         }
+
+        final ComponentRewriter componentRewriter = protocol.getComponentRewriter();
+        if (componentRewriter != null) {
+            // Handle name and lore components
+            updateComponent(connection, item, StructuredDataKey.ITEM_NAME, "item_name");
+            updateComponent(connection, item, StructuredDataKey.CUSTOM_NAME, "custom_name");
+
+            final StructuredData<Tag[]> loreData = dataContainer.getNonEmpty(StructuredDataKey.LORE);
+            if (loreData != null) {
+                for (final Tag tag : loreData.value()) {
+                    componentRewriter.processTag(connection, tag);
+                }
+            }
+        }
+
+        Int2IntFunction itemIdRewriter = null;
+        Int2IntFunction blockIdRewriter = null;
+        if (mappingData != null) {
+            itemIdRewriter = mappingData.getItemMappings() != null ? mappingData::getNewItemId : null;
+            blockIdRewriter = mappingData.getBlockMappings() != null ? mappingData::getNewBlockId : null;
+        }
+        updateItemComponents(connection, dataContainer, this::handleItemToClient, itemIdRewriter, blockIdRewriter);
         return item;
     }
 
@@ -61,14 +97,129 @@ public class StructuredItemRewriter<C extends ClientboundPacketType, S extends S
         }
 
         final MappingData mappingData = protocol.getMappingData();
+        final StructuredDataContainer dataContainer = item.dataContainer();
         if (mappingData != null) {
             if (mappingData.getItemMappings() != null) {
                 item.setIdentifier(mappingData.getOldItemId(item.identifier()));
             }
-            if (mappingData.getDataComponentSerializerMappings() != null) {
-                item.dataContainer().setIdLookup(protocol, false);
+
+            final FullMappings dataComponentMappings = mappingData.getDataComponentSerializerMappings();
+            if (dataComponentMappings != null) {
+                dataContainer.setIdLookup(protocol, false);
+                dataContainer.updateIds(protocol, id -> dataComponentMappings.inverse().getNewId(id));
             }
         }
+
+        restoreTextComponents(item);
+
+        Int2IntFunction itemIdRewriter = null;
+        Int2IntFunction blockIdRewriter = null;
+        if (mappingData != null) {
+            itemIdRewriter = mappingData.getItemMappings() != null ? mappingData::getOldItemId : null;
+            blockIdRewriter = mappingData.getBlockMappings() != null ? mappingData::getOldBlockId : null;
+        }
+        updateItemComponents(connection, dataContainer, this::handleItemToServer, itemIdRewriter, blockIdRewriter);
         return item;
     }
+
+    protected void updateItemComponents(UserConnection connection, StructuredDataContainer container, ItemHandler itemHandler, @Nullable Int2IntFunction idRewriter, @Nullable Int2IntFunction blockIdRewriter) {
+        // Specific types that need deep handling
+        if (idRewriter != null) {
+            container.updateIfPresent(StructuredDataKey.TRIM, value -> value.rewrite(idRewriter));
+            container.updateIfPresent(StructuredDataKey.POT_DECORATIONS, value -> value.rewrite(idRewriter));
+        }
+        if (blockIdRewriter != null) {
+            container.updateIfPresent(StructuredDataKey.TOOL, value -> value.rewrite(blockIdRewriter));
+            container.updateIfPresent(StructuredDataKey.CAN_PLACE_ON, value -> value.rewrite(blockIdRewriter));
+            container.updateIfPresent(StructuredDataKey.CAN_BREAK, value -> value.rewrite(blockIdRewriter));
+        }
+
+        // Look for item types
+        for (final Map.Entry<StructuredDataKey<?>, StructuredData<?>> entry : container.data().entrySet()) {
+            final StructuredData<?> data = entry.getValue();
+            if (data.isEmpty()) {
+                continue;
+            }
+
+            final StructuredDataKey<?> key = entry.getKey();
+            final Class<?> outputClass = key.type().getOutputClass();
+            if (outputClass == Item.class) {
+                //noinspection unchecked
+                final StructuredData<Item> itemData = (StructuredData<Item>) data;
+                itemData.setValue(itemHandler.rewrite(connection, itemData.value()));
+            } else if (outputClass == Item[].class) {
+                //noinspection unchecked
+                final StructuredData<Item[]> itemArrayData = (StructuredData<Item[]>) data;
+                final Item[] items = itemArrayData.value();
+                for (int i = 0; i < items.length; i++) {
+                    items[i] = itemHandler.rewrite(connection, items[i]);
+                }
+            }
+        }
+    }
+
+    protected void updateComponent(final UserConnection connection, final Item item, final StructuredDataKey<Tag> key, final String backupKey) {
+        final StructuredData<Tag> name = item.dataContainer().getNonEmpty(key);
+        if (name == null) {
+            return;
+        }
+
+        final Tag originalName = name.value().copy();
+        protocol.getComponentRewriter().processTag(connection, name.value());
+        if (!name.value().equals(originalName)) {
+            saveTag(createCustomTag(item), originalName, backupKey);
+        }
+    }
+
+    protected void restoreTextComponents(final Item item) {
+        final StructuredDataContainer data = item.dataContainer();
+        final StructuredData<CompoundTag> customData = data.getNonEmpty(StructuredDataKey.CUSTOM_DATA);
+        if (customData == null) {
+            return;
+        }
+
+        // Remove custom name
+        if (customData.value().remove(nbtTagName("added_custom_name")) != null) {
+            data.remove(StructuredDataKey.CUSTOM_NAME);
+        } else {
+            final Tag customName = removeBackupTag(customData.value(), "custom_name");
+            if (customName != null) {
+                data.set(StructuredDataKey.CUSTOM_NAME, customName);
+            }
+
+            final Tag itemName = removeBackupTag(customData.value(), "item_name");
+            if (itemName != null) {
+                data.set(StructuredDataKey.ITEM_NAME, itemName);
+            }
+        }
+    }
+
+    protected CompoundTag createCustomTag(final Item item) {
+        final StructuredDataContainer data = item.dataContainer();
+        final StructuredData<CompoundTag> customData = data.getNonEmpty(StructuredDataKey.CUSTOM_DATA);
+        if (customData != null) {
+            return customData.value();
+        }
+
+        final CompoundTag tag = new CompoundTag();
+        data.set(StructuredDataKey.CUSTOM_DATA, tag);
+        return tag;
+    }
+
+    protected void saveTag(final CompoundTag customData, final Tag tag, final String name) {
+        final String backupName = nbtTagName(name);
+        if (!customData.contains(backupName)) {
+            customData.put(backupName, tag);
+        }
+    }
+
+    protected @Nullable Tag removeBackupTag(final CompoundTag customData, final String tagName) {
+        return customData.remove(nbtTagName(tagName));
+    }
+
+    @FunctionalInterface
+    public interface ItemHandler {
+
+        Item rewrite(UserConnection connection, Item item);
+    }
 }

common/src/main/java/com/viaversion/viaversion/rewriter/TagRewriter.java

@@ -40,11 +40,11 @@ import org.checkerframework.checker.nullness.qual.Nullable;
 
 public class TagRewriter<C extends ClientboundPacketType> implements com.viaversion.viaversion.api.rewriter.TagRewriter {
     private static final int[] EMPTY_ARRAY = {};
-    private final Protocol<C, ?, ?, ?> protocol;
-    private final Map<RegistryType, List<TagData>> newTags = new EnumMap<>(RegistryType.class);
+    private final Map<RegistryType, List<TagData>> toAdd = new EnumMap<>(RegistryType.class);
     private final Map<RegistryType, Map<String, String>> toRename = new EnumMap<>(RegistryType.class);
     private final Map<RegistryType, Set<String>> toRemove = new EnumMap<>(RegistryType.class);
     private final Set<String> toRemoveRegistries = new HashSet<>();
+    private final Protocol<C, ?, ?, ?> protocol;
 
     public TagRewriter(final Protocol<C, ?, ?, ?> protocol) {
         this.protocol = protocol;
@@ -56,6 +56,7 @@ public class TagRewriter<C extends ClientboundPacketType> implements com.viavers
             return;
         }
 
+        // TODO Tags for player synchronized registries
         for (RegistryType type : RegistryType.getValues()) {
             List<TagData> tags = protocol.getMappingData().getTags(type);
             if (tags != null) {
@@ -174,8 +175,9 @@ public class TagRewriter<C extends ClientboundPacketType> implements com.viavers
     }
 
     public void handle(PacketWrapper wrapper, @Nullable IdRewriteFunction rewriteFunction, @Nullable List<TagData> newTags, @Nullable Map<String, String> tagsToRename, @Nullable Set<String> tagsToRemove) {
-        int tagsSize = wrapper.read(Types.VAR_INT);
+        final int tagsSize = wrapper.read(Types.VAR_INT);
         final List<TagData> tags = new ArrayList<>(newTags != null ? tagsSize + newTags.size() : tagsSize);
+        final Set<String> currentTags = new HashSet<>(tagsSize);
 
         for (int i = 0; i < tagsSize; i++) {
             String key = wrapper.read(Types.STRING);
@@ -201,6 +203,7 @@ public class TagRewriter<C extends ClientboundPacketType> implements com.viavers
             }
 
             tags.add(new TagData(key, ids));
+            currentTags.add(Key.stripMinecraftNamespace(key));
         }
 
         if (tagsToRemove != null) {
@@ -209,7 +212,11 @@ public class TagRewriter<C extends ClientboundPacketType> implements com.viavers
 
         // Add new tags if present
         if (newTags != null) {
-            tags.addAll(newTags);
+            for (final TagData tag : newTags) {
+                if (!currentTags.contains(Key.stripMinecraftNamespace(tag.identifier()))) {
+                    tags.add(tag);
+                }
+            }
         }
 
         // Write the tags
@@ -235,12 +242,12 @@ public class TagRewriter<C extends ClientboundPacketType> implements com.viavers
 
     @Override
     public @Nullable List<TagData> getNewTags(RegistryType tagType) {
-        return newTags.get(tagType);
+        return toAdd.get(tagType);
     }
 
     @Override
     public List<TagData> getOrComputeNewTags(RegistryType tagType) {
-        return newTags.computeIfAbsent(tagType, type -> new ArrayList<>());
+        return toAdd.computeIfAbsent(tagType, type -> new ArrayList<>());
     }
 
     public @Nullable IdRewriteFunction getRewriter(RegistryType tagType) {
@@ -249,6 +256,7 @@ public class TagRewriter<C extends ClientboundPacketType> implements com.viavers
             case BLOCK -> mappingData != null && mappingData.getBlockMappings() != null ? mappingData::getNewBlockId : null;
             case ITEM -> mappingData != null && mappingData.getItemMappings() != null ? mappingData::getNewItemId : null;
             case ENTITY -> protocol.getEntityRewriter() != null ? id -> protocol.getEntityRewriter().newEntityId(id) : null;
+            case ENCHANTMENT -> mappingData != null && mappingData.getEnchantmentMappings() != null ? id -> mappingData.getEnchantmentMappings().getNewId(id) : null;
             case FLUID, GAME_EVENT -> null;
         };
     }

common/src/main/java/com/viaversion/viaversion/util/ArrayUtil.java

@@ -0,0 +1,50 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2024 ViaVersion and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.viaversion.viaversion.util;
+
+import java.util.Arrays;
+
+/**
+ * For type safety and effort reasons, buffer types use arrays instead of lists.
+ * <p>
+ * This class includes simple methods to work with these arrays in case they need to be modified
+ * (obviously being more expensive due to the required array copies for every modification).
+ */
+public final class ArrayUtil {
+
+    public static <T> T[] add(final T[] array, final T element) {
+        final int length = array.length;
+        final T[] newArray = Arrays.copyOf(array, length + 1);
+        newArray[length] = element;
+        return newArray;
+    }
+
+    @SafeVarargs
+    public static <T> T[] add(final T[] array, final T... elements) {
+        final int length = array.length;
+        final T[] newArray = Arrays.copyOf(array, length + elements.length);
+        System.arraycopy(elements, 0, newArray, length, elements.length);
+        return newArray;
+    }
+
+    public static <T> T[] remove(final T[] array, final int index) {
+        final T[] newArray = Arrays.copyOf(array, array.length - 1);
+        System.arraycopy(array, index + 1, newArray, index, newArray.length - index);
+        return newArray;
+    }
+}

common/src/main/java/com/viaversion/viaversion/util/TagUtil.java

@@ -30,12 +30,9 @@ public final class TagUtil {
     }
 
     public static ListTag<CompoundTag> getRegistryEntries(final CompoundTag tag, final String key, final @Nullable ListTag<CompoundTag> defaultValue) {
-        CompoundTag registry = tag.getCompoundTag(Key.namespaced(key));
+        CompoundTag registry = getNamespacedCompoundTag(tag, key);
         if (registry == null) {
-            registry = tag.getCompoundTag(Key.stripMinecraftNamespace(key));
-            if (registry == null) {
-                return defaultValue;
-            }
+            return defaultValue;
         }
         return registry.getListTag("value", CompoundTag.class);
     }
@@ -62,6 +59,11 @@ public final class TagUtil {
         return tag.remove(Key.namespaced(key)) != null || tag.remove(Key.stripMinecraftNamespace(key)) != null;
     }
 
+    public static @Nullable CompoundTag getNamespacedCompoundTag(final CompoundTag tag, final String key) {
+        final CompoundTag compoundTag = tag.getCompoundTag(Key.namespaced(key));
+        return compoundTag != null ? compoundTag : tag.getCompoundTag(Key.stripMinecraftNamespace(key));
+    }
+
     public static Tag handleDeep(final Tag tag, final TagUpdater consumer) {
         return handleDeep(null, tag, consumer);
     }

common/src/test/java/com/viaversion/viaversion/common/dummy/DummyInitializer.java

@@ -19,7 +19,6 @@ package com.viaversion.viaversion.common.dummy;
 
 import com.viaversion.viaversion.ViaManagerImpl;
 import com.viaversion.viaversion.api.Via;
-import com.viaversion.viaversion.protocol.ProtocolManagerImpl;
 
 public final class DummyInitializer {
 
@@ -31,7 +30,10 @@ public final class DummyInitializer {
         }
 
         initialized = true;
-        Via.init(new ViaManagerImpl(new TestPlatform(), null, null, null));
-        ((ProtocolManagerImpl) Via.getManager().getProtocolManager()).registerProtocols();
+        Via.init(new ViaManagerImpl(new TestPlatform(), new TestInjector(), null, new TestLoader()));
+
+        final ViaManagerImpl manager = (ViaManagerImpl) Via.getManager();
+        manager.init();
+        manager.onServerLoaded();
     }
 }

common/src/test/java/com/viaversion/viaversion/common/dummy/TestInjector.java

@@ -0,0 +1,44 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2024 ViaVersion and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.viaversion.viaversion.common.dummy;
+
+import com.google.gson.JsonObject;
+import com.viaversion.viaversion.api.platform.ViaInjector;
+import com.viaversion.viaversion.api.protocol.version.ProtocolVersion;
+
+public class TestInjector implements ViaInjector {
+
+    @Override
+    public void inject() {
+    }
+
+    @Override
+    public void uninject() {
+
+    }
+
+    @Override
+    public ProtocolVersion getServerProtocolVersion() {
+        return ProtocolVersion.v1_15_2;
+    }
+
+    @Override
+    public JsonObject getDump() {
+        return null;
+    }
+}

common/src/test/java/com/viaversion/viaversion/common/dummy/TestLoader.java

@@ -0,0 +1,31 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2024 ViaVersion and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.viaversion.viaversion.common.dummy;
+
+import com.viaversion.viaversion.api.platform.ViaPlatformLoader;
+
+public class TestLoader implements ViaPlatformLoader {
+
+    @Override
+    public void load() {
+    }
+
+    @Override
+    public void unload() {
+    }
+}

gradle.properties

@@ -1,9 +1,9 @@
 # Project properties - we put these here so they can be modified without causing a recompile of the build scripts
-projectVersion=5.0.0-SNAPSHOT
+projectVersion=5.0.1
 
 # Smile emoji
-mcVersions=1.20.6,1.20.5,1.20.4, 1.20.3, 1.20.2, 1.20.1, 1.20, 1.19.4, 1.19.3, 1.19.2, 1.19.1, 1.19, 1.18.2, 1.18.1, 1.18, 1.17.1, 1.17, 1.16.5, 1.16.4, 1.16.3, 1.16.2, 1.16.1, 1.16, 1.15.2, 1.15.1, 1.15, 1.14.4, 1.14.3, 1.14.2, 1.14.1, 1.14, 1.13.2, 1.13.1, 1.13, 1.12.2, 1.12.1, 1.12, 1.11.2, 1.11.1, 1.11, 1.10.2, 1.10.1, 1.10, 1.9.4, 1.9.3, 1.9.2, 1.9.1, 1.9, 1.8.9
-mcVersionRange=1.8-1.20.6
+mcVersions=1.21,1.20.6,1.20.5,1.20.4, 1.20.3, 1.20.2, 1.20.1, 1.20, 1.19.4, 1.19.3, 1.19.2, 1.19.1, 1.19, 1.18.2, 1.18.1, 1.18, 1.17.1, 1.17, 1.16.5, 1.16.4, 1.16.3, 1.16.2, 1.16.1, 1.16, 1.15.2, 1.15.1, 1.15, 1.14.4, 1.14.3, 1.14.2, 1.14.1, 1.14, 1.13.2, 1.13.1, 1.13, 1.12.2, 1.12.1, 1.12, 1.11.2, 1.11.1, 1.11, 1.10.2, 1.10.1, 1.10, 1.9.4, 1.9.3, 1.9.2, 1.9.1, 1.9, 1.8.9
+mcVersionRange=1.8-1.21
 velocityVersion=3.3
 
 # Gradle properties

gradle/libs.versions.toml

@@ -4,7 +4,7 @@ metadata.format.version = "1.1"
 
 gson = "2.10.1"
 fastutil = "8.5.12"
-vianbt = "5.0.0-SNAPSHOT"
+vianbt = "5.0.0"
 mcstructs = "5-2.5.0-SNAPSHOT"
 
 # Common provided