5.3.0 Release

Fixes desyncs on item drags due to missing item data for 1.21.5+ clients

README.md

@@ -18,7 +18,7 @@ Supported Versions:
 
 ![Table (https://i.imgur.com/zrQTcf0.png)](https://i.imgur.com/zrQTcf0.png)
 
-**User Docs:** https://docs.viaversion.com/display/VIAVERSION/
+**User Docs:** https://docs.viaversion.com
 
 Snapshot support
 --------

api/src/main/java/com/viaversion/viaversion/api/ViaAPI.java

@@ -114,7 +114,8 @@ public interface ViaAPI<T> {
     ProtocolVersion getPlayerProtocolVersion(UUID uuid);
 
     /**
-     * Returns whether Via injected into this player connection.
+     * Returns whether Via injected into this player connection. Note that this method may not work on
+     * clientside implementations and is generally not recommended to be used. Use {@link ConnectionManager} instead.
      *
      * @param uuid uuid of the player
      * @return whether Via has a cached a UserConnection for this player
@@ -122,7 +123,8 @@ public interface ViaAPI<T> {
     boolean isInjected(UUID uuid);
 
     /**
-     * Returns the Via injected UserConnection if present.
+     * Returns whether Via injected into this player connection. Note that this method may not work on
+     * clientside implementations and is generally not recommended to be used. Use {@link ConnectionManager} instead.
      *
      * @param uuid uuid of the player
      * @return user connection if present

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

@@ -66,7 +66,7 @@ public interface ViaSubCommand {
      *
      * @param sender Command sender
      * @param args   Arguments
-     * @return commands executed succesfully if false, show usage
+     * @return commands executed successfully if false, show usage
      */
     boolean execute(ViaCommandSender sender, String[] args);
 

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

@@ -30,7 +30,7 @@ public interface ViaVersionCommand {
      * Register your own subcommand inside ViaVersion
      *
      * @param command Your own SubCommand instance to handle it.
-     * @throws IllegalArgumentException throws an exception when the subcommand already exists or if it's not valid, example: spacee
+     * @throws IllegalArgumentException throws an exception when the subcommand already exists or if it's not valid, example: space
      */
     void registerSubCommand(ViaSubCommand command);
 

api/src/main/java/com/viaversion/viaversion/api/connection/ConnectionManager.java

@@ -28,51 +28,81 @@ import java.util.UUID;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
- * Handles injected UserConnections
+ * Handles injected UserConnections.
+ * Check {@link UserConnection#isServerSide()} and {@link UserConnection#isClientSide()} to determine the connection type.
  */
 public interface ConnectionManager {
 
     /**
-     * Returns if Via injected into this player connection.
+     * Returns if Via has injected. See above for the connection types.
      *
-     * @param playerId player uuid
+     * @param uuid player uuid
      * @return true if the player is handled by Via
      */
-    boolean isClientConnected(UUID playerId);
+    boolean hasServerConnection(UUID uuid);
 
-    /**
-     * Frontend connections will have the UUID stored. Override this if your platform isn't always frontend.
-     * UUIDs can't be duplicate between frontend connections.
-     *
-     * @return true if the user is a frontend connection
-     */
-    default boolean isFrontEnd(UserConnection connection) {
-        return !connection.isClientSide();
+    @Deprecated
+    default boolean isClientConnected(UUID uuid) {
+        return hasServerConnection(uuid);
     }
 
     /**
-     * Returns the frontend UserConnection from the player connected to this proxy server
-     * Returns null when there isn't a server or connection was not found
-     * When ViaVersion is reloaded, this method may not return some players.
-     * <p>
-     * Note that connections are removed as soon as their channel is closed,
-     * so avoid using this method during player quits for example.
+     * Returns if Via has injected. See above for the connection types.
      *
-     * @return frontend UserConnection of the player connected to this proxy server
+     * @param uuid player uuid
+     * @return true if the player is handled by Via
      */
-    @Nullable UserConnection getConnectedClient(UUID clientIdentifier);
+    boolean hasClientConnection(UUID uuid);
 
     /**
-     * Returns the UUID from the frontend connection to this proxy server
-     * Returns null when there isn't a server or this connection isn't frontend, or it doesn't have an id
+     * Returns the server UserConnection. See above for the connection types.
      * When ViaVersion is reloaded, this method may not return some players.
      * <p>
      * Note that connections are removed as soon as their channel is closed,
      * so avoid using this method during player quits for example.
      *
-     * @return UUID of the frontend connection to this proxy server
+     * @return server UserConnection of the player or null
      */
-    @Nullable UUID getConnectedClientId(UserConnection connection);
+    @Nullable
+    UserConnection getServerConnection(UUID uuid);
+
+    @Deprecated
+    @Nullable default UserConnection getConnectedClient(UUID uuid) {
+        return getServerConnection(uuid);
+    }
+
+    /**
+     * Returns the client UserConnection. See above for the connection types.
+     * When ViaVersion is reloaded, this method may not return some players.
+     * <p>
+     * Note that connections are removed as soon as their channel is closed,
+     * so avoid using this method during player quits for example.
+     *
+     * @return client UserConnection of the player or null
+     */
+    @Nullable
+    UserConnection getClientConnection(UUID uuid);
+
+    /**
+     * Returns a map containing the UUIDs and server UserConnections
+     * When ViaVersion is reloaded, this method may not return some players.
+     *
+     * @return map containing the UUIDs and frontend UserConnections
+     */
+    Map<UUID, UserConnection> getServerConnections();
+
+    @Deprecated
+    default Map<UUID, UserConnection> getConnectedClients() {
+        return getServerConnections();
+    }
+
+    /**
+     * Returns a map containing the UUIDs and client UserConnections
+     * When ViaVersion is reloaded, this method may not return some players.
+     *
+     * @return map containing the UUIDs and client UserConnections
+     */
+    Map<UUID, UserConnection> getClientConnections();
 
     /**
      * Returns all UserConnections which are registered
@@ -84,15 +114,6 @@ public interface ConnectionManager {
      */
     Set<UserConnection> getConnections();
 
-    /**
-     * Returns a map containing the UUIDs and frontend UserConnections from players connected to this proxy server
-     * Returns empty list when there isn't a server
-     * When ViaVersion is reloaded, this method may not return some players.
-     *
-     * @return map containing the UUIDs and frontend UserConnections from players connected to this proxy server
-     */
-    Map<UUID, UserConnection> getConnectedClients();
-
     void onLoginSuccess(UserConnection connection);
 
     void onDisconnect(UserConnection connection);

api/src/main/java/com/viaversion/viaversion/api/connection/UserConnection.java

@@ -319,23 +319,35 @@ public interface UserConnection {
     void setPendingDisconnect(boolean pendingDisconnect);
 
     /**
-     * Returns whether this is a client-side connection.
-     * This is a mod integrated into the client itself, or for example a backend Velocity connection.
+     * Returns whether this is a backend connection.
+     * This is a mod integrated into the client, or for example a backend Velocity connection.
      *
-     * @return whether this is a client-side connection
+     * @return whether this is a backend connection
      */
     boolean isClientSide();
 
+    /**
+     * Returns whether this is a frontend connection.
+     * This is a plugin integrated into the server, or for example a frontend Velocity connection.
+     *
+     * @return whether this is a frontend connection
+     */
+    default boolean isServerSide() {
+        return !isClientSide();
+    }
+
     /**
      * Returns whether {@link ViaVersionConfig#blockedProtocolVersions()} should be checked for this connection.
      *
      * @return whether blocked protocols should be applied
      */
-    boolean shouldApplyBlockProtocol();
+    default boolean shouldApplyBlockProtocol() {
+        return isServerSide();
+    }
 
     /**
      * Returns a newly generated uuid that will let a packet be passed through without
-     * transformig its contents if used together with {@link PacketWrapper#PASSTHROUGH_ID}.
+     * transforming its contents if used together with {@link PacketWrapper#PASSTHROUGH_ID}.
      *
      * @return generated passthrough token
      */

api/src/main/java/com/viaversion/viaversion/api/debug/DebugHandler.java

@@ -22,7 +22,6 @@
  */
 package com.viaversion.viaversion.api.debug;
 
-import com.google.common.annotations.Beta;
 import com.viaversion.viaversion.api.Via;
 import com.viaversion.viaversion.api.protocol.packet.Direction;
 import com.viaversion.viaversion.api.protocol.packet.PacketType;
@@ -50,7 +49,6 @@ public interface DebugHandler {
      *
      * @param packetTypeName packet type name
      */
-    @Beta
     void addPacketTypeNameToLog(String packetTypeName);
 
     /**
@@ -59,7 +57,6 @@ public interface DebugHandler {
      *
      * @param packetType packet type
      */
-    @Beta
     void addPacketTypeToLog(PacketType packetType);
 
     /**
@@ -67,22 +64,44 @@ public interface DebugHandler {
      *
      * @param packetTypeName packet type name
      */
-    @Beta
     boolean removePacketTypeNameToLog(String packetTypeName);
 
     /**
      * Resets packet type filters.
      */
-    @Beta
     void clearPacketTypesToLog();
 
+    /**
+     * Sets whether packets should be logged before and after being transformed.
+     *
+     * @param logPacketTransform whether packets should be logged
+     */
+    default void setLogPacketTransform(boolean logPacketTransform) {
+        setLogPrePacketTransform(logPacketTransform);
+        setLogPostPacketTransform(logPacketTransform);
+    }
+
+    /**
+     * Returns whether packets should be logged before being transformed.
+     * Set to true by default.
+     *
+     * @return whether packets should be logged before being transformed
+     */
+    boolean logPrePacketTransform();
+
+    /**
+     * Sets whether packets should be logged before being transformed.
+     *
+     * @param logPrePacketTransform whether packets should be logged before being transformed
+     */
+    void setLogPrePacketTransform(boolean logPrePacketTransform);
+
     /**
      * Returns whether packets should be logged after being transformed.
      * Set to false by default.
      *
      * @return whether packets should be logged after being transformed
      */
-    @Beta
     boolean logPostPacketTransform();
 
     /**
@@ -90,7 +109,6 @@ public interface DebugHandler {
      *
      * @param logPostPacketTransform whether packets should be logged after being transformed
      */
-    @Beta
     void setLogPostPacketTransform(boolean logPostPacketTransform);
 
     /**
@@ -103,7 +121,6 @@ public interface DebugHandler {
      */
     boolean shouldLog(PacketWrapper wrapper, Direction direction);
 
-    @Beta
     default void enableAndLogIds(final PacketType... packetTypes) {
         setEnabled(true);
         for (final PacketType packetType : packetTypes) {

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

@@ -0,0 +1,55 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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;
+
+import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.api.type.types.misc.HolderType;
+import io.netty.buffer.ByteBuf;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+/**
+ * Represents an animal variant (e.g. for cows, pigs, chickens).
+ *
+ * @param modelType model type id
+ * @param texture texture path
+ * @param biomes biomes this variant can spawn in, if limited to specific biomes
+ */
+public record AnimalVariant(int modelType, String texture, @Nullable HolderSet biomes) {
+
+    public static HolderType<AnimalVariant> TYPE = new HolderType<>() {
+        @Override
+        public AnimalVariant readDirect(final ByteBuf buffer) {
+            final int modelType = Types.VAR_INT.readPrimitive(buffer);
+            final String texture = Types.STRING.read(buffer);
+            final HolderSet biomes = Types.OPTIONAL_HOLDER_SET.read(buffer);
+            return new AnimalVariant(modelType, texture, biomes);
+        }
+
+        @Override
+        public void writeDirect(final ByteBuf buffer, final AnimalVariant variant) {
+            Types.VAR_INT.writePrimitive(buffer, variant.modelType());
+            Types.STRING.write(buffer, variant.texture());
+            Types.OPTIONAL_HOLDER_SET.write(buffer, variant.biomes());
+        }
+    };
+}

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

@@ -0,0 +1,82 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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;
+
+public interface EitherHolder<T> {
+
+    /**
+     * Returns a direct or indirect value holder.
+     *
+     * @param value the value
+     * @param <T>   the type of the value
+     * @return a new direct holder
+     */
+    static <T> EitherHolder<T> of(final Holder<T> value) {
+        return new EitherHolderImpl<>(value, null);
+    }
+
+    /**
+     * Returns an indirect holder via the resource key.
+     *
+     * @param key  the resource key
+     * @param <T> the type of the value
+     * @return a new holder with the given resource key
+     */
+    static <T> EitherHolder<T> of(final String key) {
+        return new EitherHolderImpl<>(null, key);
+    }
+
+    /**
+     * Returns true if this holder is backed by a direct value.
+     *
+     * @return true if the holder is direct
+     * @see #hasKey()
+     */
+    boolean hasHolder();
+
+    /**
+     * Returns true if this holder has a resource key.
+     *
+     * @return true if this holder has a resource key
+     * @see #hasHolder()
+     */
+    boolean hasKey();
+
+    /**
+     * Returns the value of this holder.
+     *
+     * @return the value of this holder
+     * @throws IllegalArgumentException if this contains a resource key instead of a holder
+     * @see #hasHolder()
+     */
+    Holder<T> holder();
+
+    /**
+     * Returns the resource key.
+     *
+     * @return the resource key
+     * @throws IllegalArgumentException if this contains a holder instead of a resource key
+     * @see #hasKey()
+     */
+    String key();
+}

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

@@ -0,0 +1,55 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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;
+
+import com.google.common.base.Preconditions;
+import com.viaversion.viaversion.util.EitherImpl;
+
+final class EitherHolderImpl<T> extends EitherImpl<Holder<T>, String> implements EitherHolder<T> {
+
+    EitherHolderImpl(final Holder<T> left, final String value) {
+        super(left, value);
+    }
+
+    @Override
+    public boolean hasHolder() {
+        return isLeft();
+    }
+
+    @Override
+    public boolean hasKey() {
+        return isRight();
+    }
+
+    @Override
+    public Holder<T> holder() {
+        Preconditions.checkArgument(hasHolder(), "Either does not have a holder");
+        return left();
+    }
+
+    @Override
+    public String key() {
+        Preconditions.checkArgument(hasKey(), "Either does not have a key");
+        return right();
+    }
+}

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

@@ -22,15 +22,15 @@
  */
 package com.viaversion.viaversion.api.minecraft;
 
-import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
 import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.util.Copyable;
 import com.viaversion.viaversion.util.IdHolder;
 import io.netty.buffer.ByteBuf;
 import java.util.ArrayList;
 import java.util.List;
 
-public final class Particle implements IdHolder {
+public final class Particle implements IdHolder, Copyable {
     private final List<ParticleData<?>> arguments = new ArrayList<>(4);
     private int id;
 
@@ -73,6 +73,7 @@ public final class Particle implements IdHolder {
         arguments.set(index, new ParticleData<>(type, value));
     }
 
+    @Override
     public Particle copy() {
         final Particle particle = new Particle(id);
         for (ParticleData<?> argument : arguments) {
@@ -89,7 +90,7 @@ public final class Particle implements IdHolder {
             '}';
     }
 
-    public static final class ParticleData<T> {
+    public static final class ParticleData<T> implements Copyable {
         private final Type<T> type;
         private T value;
 
@@ -118,12 +119,9 @@ public final class Particle implements IdHolder {
             wrapper.write(type, value);
         }
 
+        @Override
         public ParticleData<T> copy() {
-            if (value instanceof Item item) {
-                return new ParticleData<>(type, (T) item.copy());
-            } else {
-                return new ParticleData<>(type, value);
-            }
+            return new ParticleData<>(type, copy(value));
         }
 
         @Override

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

@@ -23,6 +23,7 @@
 package com.viaversion.viaversion.api.minecraft;
 
 import com.viaversion.nbt.tag.Tag;
+import com.viaversion.viaversion.util.Copyable;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
@@ -31,12 +32,13 @@ import org.checkerframework.checker.nullness.qual.Nullable;
  * @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 record RegistryEntry(String key, @Nullable Tag tag) implements Copyable {
 
     public RegistryEntry withKey(final String key) {
         return new RegistryEntry(key, tag != null ? tag.copy() : null);
     }
 
+    @Override
     public RegistryEntry copy() {
         return new RegistryEntry(key, tag != null ? tag.copy() : null);
     }

api/src/main/java/com/viaversion/viaversion/api/minecraft/chunks/BaseChunk.java

@@ -143,6 +143,16 @@ public class BaseChunk implements Chunk {
         this.heightMap = heightMap;
     }
 
+    @Override
+    public Heightmap[] heightmaps() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void setHeightmaps(final Heightmap[] heightmaps) {
+        throw new UnsupportedOperationException();
+    }
+
     @Override
     public List<CompoundTag> getBlockEntities() {
         return blockEntities;

api/src/main/java/com/viaversion/viaversion/api/minecraft/chunks/Chunk.java

@@ -79,7 +79,8 @@ public interface Chunk {
      * @return chunk section bit mask, only non-null for 1.17+ chunks
      * @see #getBitmask()
      */
-    @Nullable BitSet getChunkMask();
+    @Nullable
+    BitSet getChunkMask();
 
     void setChunkMask(BitSet chunkSectionMask);
 
@@ -88,7 +89,8 @@ public interface Chunk {
      *
      * @return array of nullable chunk sections
      */
-    @Nullable ChunkSection[] getSections();
+    @Nullable
+    ChunkSection[] getSections();
 
     void setSections(ChunkSection[] sections);
 
@@ -106,10 +108,15 @@ public interface Chunk {
      *
      * @return compoundtag containing heightmaps if present
      */
-    @Nullable CompoundTag getHeightMap();
+    @Nullable
+    CompoundTag getHeightMap();
 
     void setHeightMap(@Nullable CompoundTag heightMap);
 
+    Heightmap[] heightmaps();
+
+    void setHeightmaps(Heightmap[] heightmaps);
+
     /**
      * Returns a list of block entities.
      *

api/src/main/java/com/viaversion/viaversion/api/minecraft/chunks/Chunk1_18.java

@@ -123,6 +123,16 @@ public class Chunk1_18 implements Chunk {
         this.heightMap = heightMap;
     }
 
+    @Override
+    public Heightmap[] heightmaps() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void setHeightmaps(final Heightmap[] heightmaps) {
+        throw new UnsupportedOperationException();
+    }
+
     @Override
     public List<CompoundTag> getBlockEntities() {
         throw new UnsupportedOperationException();

api/src/main/java/com/viaversion/viaversion/api/minecraft/chunks/Chunk1_21_5.java

@@ -0,0 +1,145 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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.chunks;
+
+import com.viaversion.nbt.tag.CompoundTag;
+import com.viaversion.viaversion.api.minecraft.blockentity.BlockEntity;
+import java.util.BitSet;
+import java.util.List;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+public class Chunk1_21_5 implements Chunk {
+    protected final int x;
+    protected final int z;
+    protected ChunkSection[] sections;
+    protected Heightmap[] heightmaps;
+    protected final List<BlockEntity> blockEntities;
+
+    public Chunk1_21_5(int x, int z, ChunkSection[] sections, Heightmap[] heightmaps, List<BlockEntity> blockEntities) {
+        this.x = x;
+        this.z = z;
+        this.sections = sections;
+        this.heightmaps = heightmaps;
+        this.blockEntities = blockEntities;
+    }
+
+    @Override
+    public boolean isBiomeData() {
+        return false;
+    }
+
+    @Override
+    public int getX() {
+        return x;
+    }
+
+    @Override
+    public int getZ() {
+        return z;
+    }
+
+    @Override
+    public boolean isFullChunk() {
+        return true;
+    }
+
+    @Override
+    public boolean isIgnoreOldLightData() {
+        return false;
+    }
+
+    @Override
+    public void setIgnoreOldLightData(boolean ignoreOldLightData) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public int getBitmask() {
+        return -1;
+    }
+
+    @Override
+    public void setBitmask(int bitmask) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public @Nullable BitSet getChunkMask() {
+        return null;
+    }
+
+    @Override
+    public void setChunkMask(BitSet chunkSectionMask) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public ChunkSection[] getSections() {
+        return sections;
+    }
+
+    @Override
+    public void setSections(ChunkSection[] sections) {
+        this.sections = sections;
+    }
+
+    @Override
+    public int @Nullable [] getBiomeData() {
+        return null;
+    }
+
+    @Override
+    public void setBiomeData(int @Nullable [] biomeData) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public @Nullable CompoundTag getHeightMap() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void setHeightMap(final CompoundTag heightMap) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public Heightmap[] heightmaps() {
+        return heightmaps;
+    }
+
+    @Override
+    public void setHeightmaps(final Heightmap[] heightmaps) {
+        this.heightmaps = heightmaps;
+    }
+
+    @Override
+    public List<CompoundTag> getBlockEntities() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public List<BlockEntity> blockEntities() {
+        return blockEntities;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/chunks/Heightmap.java

@@ -0,0 +1,26 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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.chunks;
+
+public record Heightmap(int type, long[] data) {
+}

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

@@ -53,6 +53,11 @@ final class EmptyStructuredData<T> implements StructuredData<T> {
         return this.key;
     }
 
+    @Override
+    public StructuredData<T> copy() {
+        return new EmptyStructuredData<>(this.key, this.id);
+    }
+
     @Override
     public T value() {
         return null;

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

@@ -59,6 +59,11 @@ final class FilledStructuredData<T> implements StructuredData<T> {
         return key;
     }
 
+    @Override
+    public StructuredData<T> copy() {
+        return new FilledStructuredData<>(this.key, this.copy(this.value), this.id);
+    }
+
     @Override
     public T value() {
         return value;

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

@@ -22,11 +22,12 @@
  */
 package com.viaversion.viaversion.api.minecraft.data;
 
+import com.viaversion.viaversion.util.Copyable;
 import com.viaversion.viaversion.util.IdHolder;
 import io.netty.buffer.ByteBuf;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
-public interface StructuredData<T> extends IdHolder {
+public interface StructuredData<T> extends IdHolder, Copyable {
 
     /**
      * Returns filled structured data, equivalent to an Optional with a value in vanilla.
@@ -52,7 +53,8 @@ public interface StructuredData<T> extends IdHolder {
         return new EmptyStructuredData<>(key, id);
     }
 
-    @Nullable T value();
+    @Nullable
+    T value();
 
     void setValue(final T value);
 
@@ -60,6 +62,9 @@ public interface StructuredData<T> extends IdHolder {
 
     StructuredDataKey<T> key();
 
+    @Override
+    StructuredData<T> copy();
+
     /**
      * Returns whether the structured data is present. Even if true, the value may be null.
      *

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

@@ -26,9 +26,11 @@ import com.google.common.base.Preconditions;
 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.Copyable;
 import com.viaversion.viaversion.util.Unit;
 import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 import it.unimi.dsi.fastutil.objects.Reference2ObjectOpenHashMap;
+import java.util.Collection;
 import java.util.Map;
 import java.util.function.Function;
 import org.checkerframework.checker.nullness.qual.Nullable;
@@ -53,7 +55,7 @@ import org.checkerframework.checker.nullness.qual.Nullable;
  * </ul>
  * Other methods (e.g. {@link #getData(StructuredDataKey)} and {@link #has(StructuredDataKey)}) will handle both empty and non-empty data.
  */
-public final class StructuredDataContainer {
+public final class StructuredDataContainer implements Copyable {
 
     private final Map<StructuredDataKey<?>, StructuredData<?>> data;
     private FullMappings lookup;
@@ -71,7 +73,7 @@ public final class StructuredDataContainer {
     }
 
     public StructuredDataContainer() {
-        this(new Reference2ObjectOpenHashMap<>());
+        this(new Reference2ObjectOpenHashMap<>(0));
     }
 
     /**
@@ -188,6 +190,20 @@ public final class StructuredDataContainer {
         this.data.remove(key);
     }
 
+    /**
+     * Removes data by the given keys.
+     *
+     * @param keys data keys
+     * @see #replace(StructuredDataKey, Function)
+     * @see #replace(StructuredDataKey, StructuredDataKey, Function)
+     * @see #replaceKey(StructuredDataKey, StructuredDataKey)
+     */
+    public void remove(final Collection<StructuredDataKey<?>> keys) {
+        for (final StructuredDataKey<?> key : keys) {
+            this.data.remove(key);
+        }
+    }
+
     /**
      * Returns whether there is data for the given key, either empty or non-empty.
      *
@@ -245,8 +261,13 @@ public final class StructuredDataContainer {
         }
     }
 
+    @Override
     public StructuredDataContainer copy() {
-        final StructuredDataContainer copy = new StructuredDataContainer(new Reference2ObjectOpenHashMap<>(data));
+        final Reference2ObjectOpenHashMap<StructuredDataKey<?>, StructuredData<?>> map = new Reference2ObjectOpenHashMap<>();
+        for (final StructuredData<?> value : data.values()) {
+            map.put(value.key(), value.copy());
+        }
+        final StructuredDataContainer copy = new StructuredDataContainer(map);
         copy.lookup = this.lookup;
         return copy;
     }

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

@@ -24,17 +24,22 @@ package com.viaversion.viaversion.api.minecraft.data;
 
 import com.viaversion.nbt.tag.CompoundTag;
 import com.viaversion.nbt.tag.Tag;
+import com.viaversion.viaversion.api.minecraft.EitherHolder;
 import com.viaversion.viaversion.api.minecraft.GameProfile;
 import com.viaversion.viaversion.api.minecraft.Holder;
 import com.viaversion.viaversion.api.minecraft.HolderSet;
+import com.viaversion.viaversion.api.minecraft.PaintingVariant;
+import com.viaversion.viaversion.api.minecraft.SoundEvent;
 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.AdventureModePredicate.AdventureModePredicateType1_21_5;
 import com.viaversion.viaversion.api.minecraft.item.data.ArmorTrim;
 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;
+import com.viaversion.viaversion.api.minecraft.item.data.BlocksAttacks;
 import com.viaversion.viaversion.api.minecraft.item.data.Consumable1_21_2;
 import com.viaversion.viaversion.api.minecraft.item.data.CustomModelData1_21_4;
 import com.viaversion.viaversion.api.minecraft.item.data.DamageResistant;
@@ -53,18 +58,24 @@ 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;
+import com.viaversion.viaversion.api.minecraft.item.data.ProvidesTrimMaterial;
 import com.viaversion.viaversion.api.minecraft.item.data.SuspiciousStewEffect;
 import com.viaversion.viaversion.api.minecraft.item.data.ToolProperties;
+import com.viaversion.viaversion.api.minecraft.item.data.TooltipDisplay;
 import com.viaversion.viaversion.api.minecraft.item.data.Unbreakable;
 import com.viaversion.viaversion.api.minecraft.item.data.UseCooldown;
+import com.viaversion.viaversion.api.minecraft.item.data.Weapon;
 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.ArrayType;
+import com.viaversion.viaversion.api.type.types.EitherType;
 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.api.type.types.version.Types1_21_2;
 import com.viaversion.viaversion.api.type.types.version.Types1_21_4;
+import com.viaversion.viaversion.api.type.types.version.Types1_21_5;
+import com.viaversion.viaversion.util.Either;
 import com.viaversion.viaversion.util.Unit;
 
 public record StructuredDataKey<T>(String identifier, Type<T> type) {
@@ -73,21 +84,27 @@ public record StructuredDataKey<T>(String identifier, Type<T> type) {
     public static final StructuredDataKey<Integer> MAX_STACK_SIZE = new StructuredDataKey<>("max_stack_size", Types.VAR_INT);
     public static final StructuredDataKey<Integer> MAX_DAMAGE = new StructuredDataKey<>("max_damage", Types.VAR_INT);
     public static final StructuredDataKey<Integer> DAMAGE = new StructuredDataKey<>("damage", Types.VAR_INT);
-    public static final StructuredDataKey<Unbreakable> UNBREAKABLE = new StructuredDataKey<>("unbreakable", Unbreakable.TYPE);
+    public static final StructuredDataKey<Unbreakable> UNBREAKABLE1_20_5 = new StructuredDataKey<>("unbreakable", Unbreakable.TYPE);
+    public static final StructuredDataKey<Unit> UNBREAKABLE1_21_5 = new StructuredDataKey<>("unbreakable", Types.EMPTY);
     public static final StructuredDataKey<Tag> CUSTOM_NAME = new StructuredDataKey<>("custom_name", Types.TAG);
     public static final StructuredDataKey<Tag> ITEM_NAME = new StructuredDataKey<>("item_name", Types.TAG);
     public static final StructuredDataKey<String> ITEM_MODEL = new StructuredDataKey<>("item_model", Types.STRING);
     public static final StructuredDataKey<Tag[]> LORE = new StructuredDataKey<>("lore", new ArrayType<>(Types.TAG, 256));
     public static final StructuredDataKey<Integer> RARITY = new StructuredDataKey<>("rarity", Types.VAR_INT);
-    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<Enchantments> ENCHANTMENTS1_20_5 = new StructuredDataKey<>("enchantments", Enchantments.TYPE1_20_5);
+    public static final StructuredDataKey<Enchantments> ENCHANTMENTS1_21_5 = new StructuredDataKey<>("enchantments", Enchantments.TYPE1_21_5);
+    public static final StructuredDataKey<AdventureModePredicate> CAN_PLACE_ON1_20_5 = new StructuredDataKey<>("can_place_on", AdventureModePredicate.TYPE1_20_5);
+    public static final StructuredDataKey<AdventureModePredicate> CAN_PLACE_ON1_21_5 = new StructuredDataKey<>("can_place_on", new AdventureModePredicateType1_21_5(Types1_21_5.STRUCTURED_DATA_ARRAY));
+    public static final StructuredDataKey<AdventureModePredicate> CAN_BREAK1_20_5 = new StructuredDataKey<>("can_break", AdventureModePredicate.TYPE1_20_5);
+    public static final StructuredDataKey<AdventureModePredicate> CAN_BREAK1_21_5 = new StructuredDataKey<>("can_break", new AdventureModePredicateType1_21_5(Types1_21_5.STRUCTURED_DATA_ARRAY));
     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<AttributeModifiers1_21> ATTRIBUTE_MODIFIERS1_21 = new StructuredDataKey<>("attribute_modifiers", AttributeModifiers1_21.TYPE1_21);
+    public static final StructuredDataKey<AttributeModifiers1_21> ATTRIBUTE_MODIFIERS1_21_5 = new StructuredDataKey<>("attribute_modifiers", AttributeModifiers1_21.TYPE1_21_5);
     public static final StructuredDataKey<Integer> CUSTOM_MODEL_DATA1_20_5 = new StructuredDataKey<>("custom_model_data", Types.VAR_INT);
     public static final StructuredDataKey<CustomModelData1_21_4> CUSTOM_MODEL_DATA1_21_4 = new StructuredDataKey<>("custom_model_data", CustomModelData1_21_4.TYPE);
     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);
+    public static final StructuredDataKey<TooltipDisplay> TOOLTIP_DISPLAY = new StructuredDataKey<>("tooltip_display", TooltipDisplay.TYPE);
     public static final StructuredDataKey<Integer> REPAIR_COST = new StructuredDataKey<>("repair_cost", Types.VAR_INT);
     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);
@@ -98,18 +115,25 @@ public record StructuredDataKey<T>(String identifier, Type<T> type) {
     public static final StructuredDataKey<Consumable1_21_2> CONSUMABLE1_21_2 = new StructuredDataKey<>("consumable", Consumable1_21_2.TYPE);
     public static final StructuredDataKey<Item> USE_REMAINDER1_21_2 = new StructuredDataKey<>("use_remainder", Types1_21_2.ITEM);
     public static final StructuredDataKey<Item> USE_REMAINDER1_21_4 = new StructuredDataKey<>("use_remainder", Types1_21_4.ITEM);
+    public static final StructuredDataKey<Item> USE_REMAINDER1_21_5 = new StructuredDataKey<>("use_remainder", Types1_21_5.ITEM);
     public static final StructuredDataKey<UseCooldown> USE_COOLDOWN = new StructuredDataKey<>("use_cooldown", UseCooldown.TYPE);
     public static final StructuredDataKey<Unit> FIRE_RESISTANT = new StructuredDataKey<>("fire_resistant", Types.EMPTY);
     public static final StructuredDataKey<DamageResistant> DAMAGE_RESISTANT = new StructuredDataKey<>("damage_resistant", DamageResistant.TYPE);
-    public static final StructuredDataKey<ToolProperties> TOOL = new StructuredDataKey<>("tool", ToolProperties.TYPE);
+    public static final StructuredDataKey<ToolProperties> TOOL1_20_5 = new StructuredDataKey<>("tool", ToolProperties.TYPE1_20_5);
+    public static final StructuredDataKey<ToolProperties> TOOL1_21_5 = new StructuredDataKey<>("tool", ToolProperties.TYPE1_21_5);
+    public static final StructuredDataKey<Weapon> WEAPON = new StructuredDataKey<>("weapon", Weapon.TYPE);
     public static final StructuredDataKey<Integer> ENCHANTABLE = new StructuredDataKey<>("enchantable", Types.VAR_INT);
-    public static final StructuredDataKey<Equippable> EQUIPPABLE = new StructuredDataKey<>("equippable", Equippable.TYPE);
+    public static final StructuredDataKey<Equippable> EQUIPPABLE1_21_2 = new StructuredDataKey<>("equippable", Equippable.TYPE1_21_2);
+    public static final StructuredDataKey<Equippable> EQUIPPABLE1_21_5 = new StructuredDataKey<>("equippable", Equippable.TYPE1_21_5);
     public static final StructuredDataKey<HolderSet> REPAIRABLE = new StructuredDataKey<>("repairable", Types.HOLDER_SET);
     public static final StructuredDataKey<Unit> GLIDER = new StructuredDataKey<>("glider", Types.EMPTY);
     public static final StructuredDataKey<String> TOOLTIP_STYLE = new StructuredDataKey<>("tooltip_style", Types.STRING);
     public static final StructuredDataKey<DeathProtection> DEATH_PROTECTION = new StructuredDataKey<>("death_protection", DeathProtection.TYPE);
-    public static final StructuredDataKey<Enchantments> STORED_ENCHANTMENTS = new StructuredDataKey<>("stored_enchantments", Enchantments.TYPE);
-    public static final StructuredDataKey<DyedColor> DYED_COLOR = new StructuredDataKey<>("dyed_color", DyedColor.TYPE);
+    public static final StructuredDataKey<BlocksAttacks> BLOCKS_ATTACKS = new StructuredDataKey<>("blocks_attacks", BlocksAttacks.TYPE);
+    public static final StructuredDataKey<Enchantments> STORED_ENCHANTMENTS1_20_5 = new StructuredDataKey<>("stored_enchantments", Enchantments.TYPE1_20_5);
+    public static final StructuredDataKey<Enchantments> STORED_ENCHANTMENTS1_21_5 = new StructuredDataKey<>("stored_enchantments", Enchantments.TYPE1_21_5);
+    public static final StructuredDataKey<DyedColor> DYED_COLOR1_20_5 = new StructuredDataKey<>("dyed_color", DyedColor.TYPE1_20_5);
+    public static final StructuredDataKey<DyedColor> DYED_COLOR1_21_5 = new StructuredDataKey<>("dyed_color", DyedColor.TYPE1_21_5);
     public static final StructuredDataKey<Integer> MAP_COLOR = new StructuredDataKey<>("map_color", Types.INT);
     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);
@@ -118,26 +142,34 @@ public record StructuredDataKey<T>(String identifier, Type<T> type) {
     public static final StructuredDataKey<Item[]> CHARGED_PROJECTILES1_21 = new StructuredDataKey<>("charged_projectiles", Types1_21.ITEM_ARRAY);
     public static final StructuredDataKey<Item[]> CHARGED_PROJECTILES1_21_2 = new StructuredDataKey<>("charged_projectiles", Types1_21_2.ITEM_ARRAY);
     public static final StructuredDataKey<Item[]> CHARGED_PROJECTILES1_21_4 = new StructuredDataKey<>("charged_projectiles", Types1_21_4.ITEM_ARRAY);
+    public static final StructuredDataKey<Item[]> CHARGED_PROJECTILES1_21_5 = new StructuredDataKey<>("charged_projectiles", Types1_21_5.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<Item[]> BUNDLE_CONTENTS1_21_2 = new StructuredDataKey<>("bundle_contents", Types1_21_2.ITEM_ARRAY);
     public static final StructuredDataKey<Item[]> BUNDLE_CONTENTS1_21_4 = new StructuredDataKey<>("bundle_contents", Types1_21_4.ITEM_ARRAY);
+    public static final StructuredDataKey<Item[]> BUNDLE_CONTENTS1_21_5 = new StructuredDataKey<>("bundle_contents", Types1_21_5.ITEM_ARRAY);
     public static final StructuredDataKey<PotionContents> POTION_CONTENTS1_20_5 = new StructuredDataKey<>("potion_contents", PotionContents.TYPE1_20_5);
     public static final StructuredDataKey<PotionContents> POTION_CONTENTS1_21_2 = new StructuredDataKey<>("potion_contents", PotionContents.TYPE1_21_2);
+    public static final StructuredDataKey<Float> POTION_DURATION_SCALE = new StructuredDataKey<>("potion_duration_scale", Types.FLOAT);
     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);
     public static final StructuredDataKey<WrittenBook> WRITTEN_BOOK_CONTENT = new StructuredDataKey<>("written_book_content", WrittenBook.TYPE);
     public static final StructuredDataKey<ArmorTrim> TRIM1_20_5 = new StructuredDataKey<>("trim", ArmorTrim.TYPE1_20_5);
     public static final StructuredDataKey<ArmorTrim> TRIM1_21_2 = new StructuredDataKey<>("trim", ArmorTrim.TYPE1_21_2);
     public static final StructuredDataKey<ArmorTrim> TRIM1_21_4 = new StructuredDataKey<>("trim", ArmorTrim.TYPE1_21_4);
+    public static final StructuredDataKey<ArmorTrim> TRIM1_21_5 = new StructuredDataKey<>("trim", ArmorTrim.TYPE1_21_5);
     public static final StructuredDataKey<CompoundTag> DEBUG_STICK_STATE = new StructuredDataKey<>("debug_stick_state", Types.COMPOUND_TAG);
     public static final StructuredDataKey<CompoundTag> ENTITY_DATA = new StructuredDataKey<>("entity_data", Types.COMPOUND_TAG);
     public static final StructuredDataKey<CompoundTag> BUCKET_ENTITY_DATA = new StructuredDataKey<>("bucket_entity_data", Types.COMPOUND_TAG);
     public static final StructuredDataKey<CompoundTag> BLOCK_ENTITY_DATA = new StructuredDataKey<>("block_entity_data", Types.COMPOUND_TAG);
     public static final StructuredDataKey<Holder<Instrument1_20_5>> INSTRUMENT1_20_5 = new StructuredDataKey<>("instrument", Instrument1_20_5.TYPE);
     public static final StructuredDataKey<Holder<Instrument1_21_2>> INSTRUMENT1_21_2 = new StructuredDataKey<>("instrument", Instrument1_21_2.TYPE);
+    public static final StructuredDataKey<EitherHolder<Instrument1_21_2>> INSTRUMENT1_21_5 = new StructuredDataKey<>("instrument", Instrument1_21_2.EITHER_HOLDER_TYPE);
+    public static final StructuredDataKey<ProvidesTrimMaterial> PROVIDES_TRIM_MATERIAL = new StructuredDataKey<>("provides_trim_material", ProvidesTrimMaterial.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<JukeboxPlayable> JUKEBOX_PLAYABLE1_21 = new StructuredDataKey<>("jukebox_playable", JukeboxPlayable.TYPE1_21);
+    public static final StructuredDataKey<JukeboxPlayable> JUKEBOX_PLAYABLE1_21_5 = new StructuredDataKey<>("jukebox_playable", JukeboxPlayable.TYPE1_21_5);
+    public static final StructuredDataKey<String> PROVIDES_BANNER_PATTERNS = new StructuredDataKey<>("provides_banner_patterns", Types.STRING);
     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);
@@ -151,10 +183,37 @@ public record StructuredDataKey<T>(String identifier, Type<T> type) {
     public static final StructuredDataKey<Item[]> CONTAINER1_21 = new StructuredDataKey<>("container", Types1_21.ITEM_ARRAY);
     public static final StructuredDataKey<Item[]> CONTAINER1_21_2 = new StructuredDataKey<>("container", new ArrayType<>(Types1_21_2.ITEM, 256));
     public static final StructuredDataKey<Item[]> CONTAINER1_21_4 = new StructuredDataKey<>("container", Types1_21_4.ITEM_ARRAY);
+    public static final StructuredDataKey<Item[]> CONTAINER1_21_5 = new StructuredDataKey<>("container", Types1_21_5.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);
     public static final StructuredDataKey<CompoundTag> CONTAINER_LOOT = new StructuredDataKey<>("container_loot", Types.COMPOUND_TAG);
+    public static final StructuredDataKey<Holder<SoundEvent>> BREAK_SOUND = new StructuredDataKey<>("break_sound", Types.SOUND_EVENT);
+
+    public static final StructuredDataKey<Integer> VILLAGER_VARIANT = new StructuredDataKey<>("villager/variant", Types.VAR_INT);
+    public static final StructuredDataKey<Integer> WOLF_VARIANT = new StructuredDataKey<>("wolf/variant", Types.VAR_INT);
+    public static final StructuredDataKey<Integer> WOLF_SOUND_VARIANT = new StructuredDataKey<>("wolf/sound_variant", Types.VAR_INT);
+    public static final StructuredDataKey<Integer> WOLF_COLLAR = new StructuredDataKey<>("wolf/collar", Types.VAR_INT);
+    public static final StructuredDataKey<Integer> FOX_VARIANT = new StructuredDataKey<>("fox/variant", Types.VAR_INT);
+    public static final StructuredDataKey<Integer> SALMON_SIZE = new StructuredDataKey<>("salmon/size", Types.VAR_INT);
+    public static final StructuredDataKey<Integer> PARROT_VARIANT = new StructuredDataKey<>("parrot/variant", Types.VAR_INT);
+    public static final StructuredDataKey<Integer> TROPICAL_FISH_PATTERN = new StructuredDataKey<>("tropical_fish/pattern", Types.VAR_INT);
+    public static final StructuredDataKey<Integer> TROPICAL_FISH_BASE_COLOR = new StructuredDataKey<>("tropical_fish/base_color", Types.VAR_INT);
+    public static final StructuredDataKey<Integer> TROPICAL_FISH_PATTERN_COLOR = new StructuredDataKey<>("tropical_fish/pattern_color", Types.VAR_INT);
+    public static final StructuredDataKey<Integer> MOOSHROOM_VARIANT = new StructuredDataKey<>("mooshroom/variant", Types.VAR_INT);
+    public static final StructuredDataKey<Integer> RABBIT_VARIANT = new StructuredDataKey<>("rabbit/variant", Types.VAR_INT);
+    public static final StructuredDataKey<Integer> PIG_VARIANT = new StructuredDataKey<>("pig/variant", Types.VAR_INT);
+    public static final StructuredDataKey<Integer> COW_VARIANT = new StructuredDataKey<>("cow/variant", Types.VAR_INT);
+    public static final StructuredDataKey<Either<Integer, String>> CHICKEN_VARIANT = new StructuredDataKey<>("chicken/variant", new EitherType<>(Types.VAR_INT, Types.STRING)); // ???
+    public static final StructuredDataKey<Integer> FROG_VARIANT = new StructuredDataKey<>("frog/variant", Types.VAR_INT);
+    public static final StructuredDataKey<Integer> HORSE_VARIANT = new StructuredDataKey<>("horse/variant", Types.VAR_INT);
+    public static final StructuredDataKey<Holder<PaintingVariant>> PAINTING_VARIANT = new StructuredDataKey<>("painting/variant", PaintingVariant.TYPE1_21_2);
+    public static final StructuredDataKey<Integer> LLAMA_VARIANT = new StructuredDataKey<>("llama/variant", Types.VAR_INT);
+    public static final StructuredDataKey<Integer> AXOLOTL_VARIANT = new StructuredDataKey<>("axolotl/variant", Types.VAR_INT);
+    public static final StructuredDataKey<Integer> CAT_VARIANT = new StructuredDataKey<>("cat/variant", Types.VAR_INT);
+    public static final StructuredDataKey<Integer> CAT_COLLAR = new StructuredDataKey<>("cat/collar", Types.VAR_INT);
+    public static final StructuredDataKey<Integer> SHEEP_COLOR = new StructuredDataKey<>("sheep/color", Types.VAR_INT);
+    public static final StructuredDataKey<Integer> SHULKER_COLOR = new StructuredDataKey<>("shulker/color", Types.VAR_INT);
 
     @Override
     public String toString() {

api/src/main/java/com/viaversion/viaversion/api/minecraft/data/predicate/DataComponentMatchers.java

@@ -0,0 +1,52 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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.data.predicate;
+
+import com.viaversion.viaversion.api.minecraft.data.StructuredData;
+import com.viaversion.viaversion.api.type.Type;
+import io.netty.buffer.ByteBuf;
+
+public record DataComponentMatchers(StructuredData<?>[] exactPredicates, DataComponentPredicate[] predicates) {
+
+    public static final class DataComponentMatchersType extends Type<DataComponentMatchers> {
+        private final Type<StructuredData<?>[]> dataArrayType;
+
+        public DataComponentMatchersType(final Type<StructuredData<?>[]> dataArrayType) {
+            super(DataComponentMatchers.class);
+            this.dataArrayType = dataArrayType;
+        }
+
+        @Override
+        public DataComponentMatchers read(final ByteBuf buffer) {
+            final StructuredData<?>[] exactPredicates = dataArrayType.read(buffer);
+            final DataComponentPredicate[] partialPredicates = DataComponentPredicate.ARRAY_TYPE.read(buffer);
+            return new DataComponentMatchers(exactPredicates, partialPredicates);
+        }
+
+        @Override
+        public void write(final ByteBuf buffer, final DataComponentMatchers value) {
+            dataArrayType.write(buffer, value.exactPredicates());
+            DataComponentPredicate.ARRAY_TYPE.write(buffer, value.predicates());
+        }
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/data/predicate/DataComponentPredicate.java

@@ -0,0 +1,48 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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.data.predicate;
+
+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.ArrayType;
+import io.netty.buffer.ByteBuf;
+
+public record DataComponentPredicate(int id, Tag predicate) {
+
+    public static final Type<DataComponentPredicate> TYPE = new Type<>(DataComponentPredicate.class) {
+        @Override
+        public DataComponentPredicate read(final ByteBuf buffer) {
+            final int id = Types.VAR_INT.readPrimitive(buffer);
+            final Tag predicate = Types.TAG.read(buffer);
+            return new DataComponentPredicate(id, predicate);
+        }
+
+        @Override
+        public void write(final ByteBuf buffer, final DataComponentPredicate value) {
+            Types.VAR_INT.writePrimitive(buffer, value.id());
+            Types.TAG.write(buffer, value.predicate());
+        }
+    };
+    public static final Type<DataComponentPredicate[]> ARRAY_TYPE = new ArrayType<>(TYPE, 64);
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/EntityTypes1_10.java

@@ -27,17 +27,6 @@ import java.util.Map;
 
 public class EntityTypes1_10 {
 
-    public static EntityType getTypeFromId(final int typeId, final boolean object) {
-        EntityType type;
-
-        if (object) {
-            type = ObjectType.getEntityType(typeId);
-        } else {
-            type = EntityType.findById(typeId);
-        }
-        return type;
-    }
-
     public enum EntityType implements com.viaversion.viaversion.api.minecraft.entities.EntityType {
 
         ENTITY,
@@ -212,7 +201,13 @@ public class EntityTypes1_10 {
         BOAT(1, EntityType.BOAT),
         ITEM(2, EntityType.ITEM),
         AREA_EFFECT_CLOUD(3, EntityType.AREA_EFFECT_CLOUD),
-        MINECART(10, EntityType.MINECART), // There are multiple types, but we don't need them
+        MINECART(10, EntityType.MINECART),
+        CHEST_MINECART(10, 1, EntityType.CHEST_MINECART),
+        FURNACE_MINECART(10, 2, EntityType.FURNACE_MINECART),
+        TNT_MINECART(10, 3, EntityType.TNT_MINECART),
+        SPAWNER_MINECART(10, 4, EntityType.SPAWNER_MINECART),
+        HOPPER_MINECART(10, 5, EntityType.HOPPER_MINECART),
+        COMMAND_BLOCK_MINECART(10, 6, EntityType.COMMAND_BLOCK_MINECART),
         TNT_PRIMED(50, EntityType.TNT),
         ENDER_CRYSTAL(51, EntityType.END_CRYSTAL),
         TIPPED_ARROW(60, EntityType.ARROW),
@@ -235,19 +230,25 @@ public class EntityTypes1_10 {
         SPECTRAL_ARROW(91, EntityType.SPECTRAL_ARROW),
         DRAGON_FIREBALL(93, EntityType.DRAGON_FIREBALL);
 
-        private static final Map<Integer, ObjectType> TYPES = new HashMap<>();
+        private static final Map<Integer, Map<Integer, ObjectType>> TYPES = new HashMap<>();
 
         private final int id;
+        private final int data;
         private final EntityType type;
 
         static {
             for (ObjectType type : ObjectType.values()) {
-                TYPES.put(type.id, type);
+                TYPES.computeIfAbsent(type.id, k -> new HashMap<>()).put(type.data, type);
             }
         }
 
         ObjectType(int id, EntityType type) {
+            this(id, 0, type);
+        }
+
+        ObjectType(int id, int data, EntityType type) {
             this.id = id;
+            this.data = data;
             this.type = type;
         }
 
@@ -256,20 +257,28 @@ public class EntityTypes1_10 {
             return id;
         }
 
+        @Override
+        public int getData() {
+            return data;
+        }
+
         @Override
         public EntityType getType() {
             return type;
         }
 
-        public static ObjectType findById(final int id) {
-            if (id == -1) {
+        public static ObjectType findById(final int id, final int data) {
+            final Map<Integer, ObjectType> types = TYPES.get(id);
+            if (types == null) {
                 return null;
             }
-            return TYPES.get(id);
+
+            final ObjectType type = types.get(data);
+            return type != null ? type : types.get(0);
         }
 
-        public static EntityType getEntityType(final int id) {
-            final ObjectType objectType = findById(id);
+        public static EntityType getEntityType(final int id, final int data) {
+            final ObjectType objectType = findById(id, data);
             return objectType != null ? objectType.type : null;
         }
     }

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/EntityTypes1_11.java

@@ -27,17 +27,6 @@ import java.util.Map;
 
 public class EntityTypes1_11 {
 
-    public static EntityType getTypeFromId(final int typeId, final boolean object) {
-        EntityType type;
-
-        if (object) {
-            type = ObjectType.getEntityType(typeId);
-        } else {
-            type = EntityType.findById(typeId);
-        }
-        return type;
-    }
-
     public enum EntityType implements com.viaversion.viaversion.api.minecraft.entities.EntityType {
 
         ENTITY,
@@ -237,7 +226,13 @@ public class EntityTypes1_11 {
         BOAT(1, EntityType.BOAT),
         ITEM(2, EntityType.ITEM),
         AREA_EFFECT_CLOUD(3, EntityType.AREA_EFFECT_CLOUD),
-        MINECART(10, EntityType.MINECART), // There are multiple types, but we don't need them
+        MINECART(10, EntityType.MINECART),
+        CHEST_MINECART(10, 1, EntityType.CHEST_MINECART),
+        FURNACE_MINECART(10, 2, EntityType.FURNACE_MINECART),
+        TNT_MINECART(10, 3, EntityType.TNT_MINECART),
+        SPAWNER_MINECART(10, 4, EntityType.SPAWNER_MINECART),
+        HOPPER_MINECART(10, 5, EntityType.HOPPER_MINECART),
+        COMMAND_BLOCK_MINECART(10, 6, EntityType.COMMAND_BLOCK_MINECART),
         TNT_PRIMED(50, EntityType.TNT),
         ENDER_CRYSTAL(51, EntityType.END_CRYSTAL),
         TIPPED_ARROW(60, EntityType.ARROW),
@@ -262,19 +257,25 @@ public class EntityTypes1_11 {
         SPECTRAL_ARROW(91, EntityType.SPECTRAL_ARROW),
         DRAGON_FIREBALL(93, EntityType.DRAGON_FIREBALL);
 
-        private static final Map<Integer, ObjectType> TYPES = new HashMap<>();
+        private static final Map<Integer, Map<Integer, ObjectType>> TYPES = new HashMap<>();
 
         private final int id;
+        private final int data;
         private final EntityType type;
 
         static {
             for (ObjectType type : ObjectType.values()) {
-                TYPES.put(type.id, type);
+                TYPES.computeIfAbsent(type.id, k -> new HashMap<>()).put(type.data, type);
             }
         }
 
         ObjectType(int id, EntityType type) {
+            this(id, 0, type);
+        }
+
+        ObjectType(int id, int data, EntityType type) {
             this.id = id;
+            this.data = data;
             this.type = type;
         }
 
@@ -283,20 +284,28 @@ public class EntityTypes1_11 {
             return id;
         }
 
+        @Override
+        public int getData() {
+            return data;
+        }
+
         @Override
         public EntityType getType() {
             return type;
         }
 
-        public static ObjectType findById(final int id) {
-            if (id == -1) {
+        public static ObjectType findById(final int id, final int data) {
+            final Map<Integer, ObjectType> types = TYPES.get(id);
+            if (types == null) {
                 return null;
             }
-            return TYPES.get(id);
+
+            final ObjectType type = types.get(data);
+            return type != null ? type : types.get(0);
         }
 
-        public static EntityType getEntityType(final int id) {
-            final ObjectType objectType = findById(id);
+        public static EntityType getEntityType(final int id, final int data) {
+            final ObjectType objectType = findById(id, data);
             return objectType != null ? objectType.type : null;
         }
     }

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/EntityTypes1_12.java

@@ -27,17 +27,6 @@ import java.util.Map;
 
 public class EntityTypes1_12 {
 
-    public static EntityType getTypeFromId(final int typeId, final boolean object) {
-        EntityType type;
-
-        if (object) {
-            type = ObjectType.getEntityType(typeId);
-        } else {
-            type = EntityType.findById(typeId);
-        }
-        return type;
-    }
-
     public enum EntityType implements com.viaversion.viaversion.api.minecraft.entities.EntityType {
 
         ENTITY,
@@ -243,7 +232,13 @@ public class EntityTypes1_12 {
         BOAT(1, EntityType.BOAT),
         ITEM(2, EntityType.ITEM),
         AREA_EFFECT_CLOUD(3, EntityType.AREA_EFFECT_CLOUD),
-        MINECART(10, EntityType.MINECART), // There are multiple types, but we don't need them
+        MINECART(10, EntityType.MINECART),
+        CHEST_MINECART(10, 1, EntityType.CHEST_MINECART),
+        FURNACE_MINECART(10, 2, EntityType.FURNACE_MINECART),
+        TNT_MINECART(10, 3, EntityType.TNT_MINECART),
+        SPAWNER_MINECART(10, 4, EntityType.SPAWNER_MINECART),
+        HOPPER_MINECART(10, 5, EntityType.HOPPER_MINECART),
+        COMMAND_BLOCK_MINECART(10, 6, EntityType.COMMAND_BLOCK_MINECART),
         TNT_PRIMED(50, EntityType.TNT),
         ENDER_CRYSTAL(51, EntityType.END_CRYSTAL),
         TIPPED_ARROW(60, EntityType.ARROW),
@@ -268,19 +263,25 @@ public class EntityTypes1_12 {
         SPECTRAL_ARROW(91, EntityType.SPECTRAL_ARROW),
         DRAGON_FIREBALL(93, EntityType.DRAGON_FIREBALL);
 
-        private static final Map<Integer, ObjectType> TYPES = new HashMap<>();
+        private static final Map<Integer, Map<Integer, ObjectType>> TYPES = new HashMap<>();
 
         private final int id;
+        private final int data;
         private final EntityType type;
 
         static {
             for (ObjectType type : ObjectType.values()) {
-                TYPES.put(type.id, type);
+                TYPES.computeIfAbsent(type.id, k -> new HashMap<>()).put(type.data, type);
             }
         }
 
         ObjectType(int id, EntityType type) {
+            this(id, 0, type);
+        }
+
+        ObjectType(int id, int data, EntityType type) {
             this.id = id;
+            this.data = data;
             this.type = type;
         }
 
@@ -289,20 +290,28 @@ public class EntityTypes1_12 {
             return id;
         }
 
+        @Override
+        public int getData() {
+            return data;
+        }
+
         @Override
         public EntityType getType() {
             return type;
         }
 
-        public static ObjectType findById(final int id) {
-            if (id == -1) {
+        public static ObjectType findById(final int id, final int data) {
+            final Map<Integer, ObjectType> types = TYPES.get(id);
+            if (types == null) {
                 return null;
             }
-            return TYPES.get(id);
+
+            final ObjectType type = types.get(data);
+            return type != null ? type : types.get(0);
         }
 
-        public static EntityType getEntityType(final int id) {
-            final ObjectType objectType = findById(id);
+        public static EntityType getEntityType(final int id, final int data) {
+            final ObjectType objectType = findById(id, data);
             return objectType != null ? objectType.type : null;
         }
     }

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/EntityTypes1_13.java

@@ -27,17 +27,6 @@ import java.util.Map;
 
 public class EntityTypes1_13 {
 
-    public static EntityType getTypeFromId(final int typeId, final boolean object) {
-        EntityType type;
-
-        if (object) {
-            type = ObjectType.getEntityType(typeId);
-        } else {
-            type = EntityType.findById(typeId);
-        }
-        return type;
-    }
-
     public enum EntityType implements com.viaversion.viaversion.api.minecraft.entities.EntityType {
 
         ENTITY,
@@ -254,7 +243,13 @@ public class EntityTypes1_13 {
         BOAT(1, EntityType.BOAT),
         ITEM(2, EntityType.ITEM),
         AREA_EFFECT_CLOUD(3, EntityType.AREA_EFFECT_CLOUD),
-        MINECART(10, EntityType.MINECART), // There are multiple types, but we don't need them
+        MINECART(10, EntityType.MINECART),
+        CHEST_MINECART(10, 1, EntityType.CHEST_MINECART),
+        FURNACE_MINECART(10, 2, EntityType.FURNACE_MINECART),
+        TNT_MINECART(10, 3, EntityType.TNT_MINECART),
+        SPAWNER_MINECART(10, 4, EntityType.SPAWNER_MINECART),
+        HOPPER_MINECART(10, 5, EntityType.HOPPER_MINECART),
+        COMMAND_BLOCK_MINECART(10, 6, EntityType.COMMAND_BLOCK_MINECART),
         TNT_PRIMED(50, EntityType.TNT),
         ENDER_CRYSTAL(51, EntityType.END_CRYSTAL),
         TIPPED_ARROW(60, EntityType.ARROW),
@@ -280,19 +275,25 @@ public class EntityTypes1_13 {
         DRAGON_FIREBALL(93, EntityType.DRAGON_FIREBALL),
         TRIDENT(94, EntityType.TRIDENT);
 
-        private static final Map<Integer, ObjectType> TYPES = new HashMap<>();
+        private static final Map<Integer, Map<Integer, ObjectType>> TYPES = new HashMap<>();
 
         private final int id;
+        private final int data;
         private final EntityType type;
 
         static {
             for (ObjectType type : ObjectType.values()) {
-                TYPES.put(type.id, type);
+                TYPES.computeIfAbsent(type.id, k -> new HashMap<>()).put(type.data, type);
             }
         }
 
         ObjectType(int id, EntityType type) {
+            this(id, 0, type);
+        }
+
+        ObjectType(int id, int data, EntityType type) {
             this.id = id;
+            this.data = data;
             this.type = type;
         }
 
@@ -301,20 +302,28 @@ public class EntityTypes1_13 {
             return id;
         }
 
+        @Override
+        public int getData() {
+            return data;
+        }
+
         @Override
         public EntityType getType() {
             return type;
         }
 
-        public static ObjectType findById(final int id) {
-            if (id == -1) {
+        public static ObjectType findById(final int id, final int data) {
+            final Map<Integer, ObjectType> types = TYPES.get(id);
+            if (types == null) {
                 return null;
             }
-            return TYPES.get(id);
+
+            final ObjectType type = types.get(data);
+            return type != null ? type : types.get(0);
         }
 
-        public static EntityType getEntityType(final int id) {
-            final ObjectType objectType = findById(id);
+        public static EntityType getEntityType(final int id, final int data) {
+            final ObjectType objectType = findById(id, data);
             return objectType != null ? objectType.type : null;
         }
     }

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/EntityTypes1_21_5.java

@@ -0,0 +1,317 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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.entities;
+
+import com.google.common.base.Preconditions;
+import com.viaversion.viaversion.api.protocol.Protocol;
+import com.viaversion.viaversion.util.EntityTypeUtil;
+import com.viaversion.viaversion.util.Key;
+import java.util.Locale;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+public enum EntityTypes1_21_5 implements EntityType {
+
+    ENTITY(null, null),
+
+    AREA_EFFECT_CLOUD(ENTITY),
+    END_CRYSTAL(ENTITY),
+    EVOKER_FANGS(ENTITY),
+    EXPERIENCE_ORB(ENTITY),
+    EYE_OF_ENDER(ENTITY),
+    FALLING_BLOCK(ENTITY),
+    ITEM(ENTITY),
+    TNT(ENTITY),
+    OMINOUS_ITEM_SPAWNER(ENTITY),
+    MARKER(ENTITY),
+    LIGHTNING_BOLT(ENTITY),
+    INTERACTION(ENTITY),
+
+    DISPLAY(ENTITY, null),
+    BLOCK_DISPLAY(DISPLAY),
+    ITEM_DISPLAY(DISPLAY),
+    TEXT_DISPLAY(DISPLAY),
+
+    // Hanging entities
+    HANGING_ENTITY(ENTITY, null),
+    LEASH_KNOT(HANGING_ENTITY),
+    PAINTING(HANGING_ENTITY),
+    ITEM_FRAME(HANGING_ENTITY),
+    GLOW_ITEM_FRAME(ITEM_FRAME),
+
+    // Projectiles
+    PROJECTILE(ENTITY, null),
+    ITEM_PROJECTILE(PROJECTILE, null),
+    SNOWBALL(ITEM_PROJECTILE),
+    ENDER_PEARL(ITEM_PROJECTILE),
+    EGG(ITEM_PROJECTILE),
+    EXPERIENCE_BOTTLE(ITEM_PROJECTILE),
+    FIREWORK_ROCKET(PROJECTILE),
+    LLAMA_SPIT(PROJECTILE),
+    SHULKER_BULLET(PROJECTILE),
+    FISHING_BOBBER(PROJECTILE),
+    WITHER_SKULL(PROJECTILE),
+    DRAGON_FIREBALL(PROJECTILE), // Doesn't actually inherit fireball
+
+    ABSTRACT_THROWN_POTION(ITEM_PROJECTILE, null),
+    SPLASH_POTION(ABSTRACT_THROWN_POTION),
+    LINGERING_POTION(ABSTRACT_THROWN_POTION),
+
+    ABSTRACT_ARROW(PROJECTILE, null),
+    ARROW(ABSTRACT_ARROW),
+    SPECTRAL_ARROW(ABSTRACT_ARROW),
+    TRIDENT(ABSTRACT_ARROW),
+
+    ABSTRACT_FIREBALL(ENTITY, null),
+    FIREBALL(ABSTRACT_FIREBALL),
+    SMALL_FIREBALL(ABSTRACT_FIREBALL),
+
+    ABSTRACT_WIND_CHARGE(PROJECTILE, null),
+    WIND_CHARGE(ABSTRACT_WIND_CHARGE),
+    BREEZE_WIND_CHARGE(ABSTRACT_WIND_CHARGE),
+
+    // Vehicles
+    VEHICLE(ENTITY, null),
+
+    ABSTRACT_MINECART(VEHICLE, null),
+    MINECART(ABSTRACT_MINECART),
+    FURNACE_MINECART(ABSTRACT_MINECART),
+    COMMAND_BLOCK_MINECART(ABSTRACT_MINECART),
+    TNT_MINECART(ABSTRACT_MINECART),
+    SPAWNER_MINECART(ABSTRACT_MINECART),
+
+    ABSTRACT_MINECART_CONTAINER(ABSTRACT_MINECART, null),
+    CHEST_MINECART(ABSTRACT_MINECART_CONTAINER),
+    HOPPER_MINECART(ABSTRACT_MINECART_CONTAINER),
+
+    ABSTRACT_BOAT(VEHICLE, null),
+    ABSTRACT_CHEST_BOAT(ABSTRACT_BOAT, null),
+    ACACIA_BOAT(ABSTRACT_BOAT),
+    ACACIA_CHEST_BOAT(ABSTRACT_CHEST_BOAT),
+    BAMBOO_CHEST_RAFT(ABSTRACT_CHEST_BOAT),
+    BAMBOO_RAFT(ABSTRACT_BOAT),
+    BIRCH_BOAT(ABSTRACT_BOAT),
+    BIRCH_CHEST_BOAT(ABSTRACT_CHEST_BOAT),
+    CHERRY_BOAT(ABSTRACT_BOAT),
+    CHERRY_CHEST_BOAT(ABSTRACT_CHEST_BOAT),
+    DARK_OAK_BOAT(ABSTRACT_BOAT),
+    DARK_OAK_CHEST_BOAT(ABSTRACT_CHEST_BOAT),
+    JUNGLE_BOAT(ABSTRACT_BOAT),
+    JUNGLE_CHEST_BOAT(ABSTRACT_CHEST_BOAT),
+    MANGROVE_BOAT(ABSTRACT_BOAT),
+    MANGROVE_CHEST_BOAT(ABSTRACT_CHEST_BOAT),
+    OAK_BOAT(ABSTRACT_BOAT),
+    OAK_CHEST_BOAT(ABSTRACT_CHEST_BOAT),
+    PALE_OAK_BOAT(ABSTRACT_BOAT),
+    PALE_OAK_CHEST_BOAT(ABSTRACT_CHEST_BOAT),
+    SPRUCE_BOAT(ABSTRACT_BOAT),
+    SPRUCE_CHEST_BOAT(ABSTRACT_CHEST_BOAT),
+
+    // Living entities as a larger subclass
+    LIVING_ENTITY(ENTITY, null),
+    ARMOR_STAND(LIVING_ENTITY),
+    PLAYER(LIVING_ENTITY),
+
+    // Mobs as a larger subclass
+    MOB(LIVING_ENTITY, null),
+    ENDER_DRAGON(MOB),
+
+    SLIME(MOB),
+    MAGMA_CUBE(SLIME),
+
+    // Ambient mobs
+    AMBIENT_CREATURE(MOB, null),
+    BAT(AMBIENT_CREATURE),
+
+    // Flying mobs
+    FLYING_MOB(MOB, null),
+    GHAST(FLYING_MOB),
+    PHANTOM(FLYING_MOB),
+
+    // Pathfinder mobs and its subclasses
+    PATHFINDER_MOB(MOB, null),
+    ALLAY(PATHFINDER_MOB),
+
+    ABSTRACT_GOLEM(PATHFINDER_MOB, null),
+    SNOW_GOLEM(ABSTRACT_GOLEM),
+    IRON_GOLEM(ABSTRACT_GOLEM),
+    SHULKER(ABSTRACT_GOLEM),
+
+    // Ageable mobs and (tamable) animals
+    ABSTRACT_AGEABLE(PATHFINDER_MOB, null),
+    ABSTRACT_VILLAGER(ABSTRACT_AGEABLE, null),
+    VILLAGER(ABSTRACT_VILLAGER),
+    WANDERING_TRADER(ABSTRACT_VILLAGER),
+
+    ABSTRACT_ANIMAL(ABSTRACT_AGEABLE, null),
+    AXOLOTL(ABSTRACT_ANIMAL),
+    CHICKEN(ABSTRACT_ANIMAL),
+    PANDA(ABSTRACT_ANIMAL),
+    PIG(ABSTRACT_ANIMAL),
+    POLAR_BEAR(ABSTRACT_ANIMAL),
+    RABBIT(ABSTRACT_ANIMAL),
+    SHEEP(ABSTRACT_ANIMAL),
+    BEE(ABSTRACT_ANIMAL),
+    TURTLE(ABSTRACT_ANIMAL),
+    FOX(ABSTRACT_ANIMAL),
+    FROG(ABSTRACT_ANIMAL),
+    GOAT(ABSTRACT_ANIMAL),
+    HOGLIN(ABSTRACT_ANIMAL),
+    STRIDER(ABSTRACT_ANIMAL),
+    SNIFFER(ABSTRACT_ANIMAL),
+    ARMADILLO(ABSTRACT_ANIMAL),
+
+    ABSTRACT_COW(ABSTRACT_ANIMAL, null),
+    COW(ABSTRACT_COW),
+    MOOSHROOM(ABSTRACT_COW),
+
+    TAMABLE_ANIMAL(ABSTRACT_ANIMAL, null),
+    CAT(TAMABLE_ANIMAL),
+    OCELOT(TAMABLE_ANIMAL),
+    WOLF(TAMABLE_ANIMAL),
+    PARROT(TAMABLE_ANIMAL),
+
+    ABSTRACT_HORSE(ABSTRACT_ANIMAL, null),
+    HORSE(ABSTRACT_HORSE),
+    SKELETON_HORSE(ABSTRACT_HORSE),
+    ZOMBIE_HORSE(ABSTRACT_HORSE),
+    CAMEL(ABSTRACT_HORSE),
+
+    ABSTRACT_CHESTED_HORSE(ABSTRACT_HORSE, null),
+    DONKEY(ABSTRACT_CHESTED_HORSE),
+    MULE(ABSTRACT_CHESTED_HORSE),
+    LLAMA(ABSTRACT_CHESTED_HORSE),
+    TRADER_LLAMA(LLAMA),
+
+    // Monsters
+    ABSTRACT_MONSTER(PATHFINDER_MOB, null),
+    BLAZE(ABSTRACT_MONSTER),
+    CREEPER(ABSTRACT_MONSTER),
+    ENDERMITE(ABSTRACT_MONSTER),
+    ENDERMAN(ABSTRACT_MONSTER),
+    GIANT(ABSTRACT_MONSTER),
+    SILVERFISH(ABSTRACT_MONSTER),
+    VEX(ABSTRACT_MONSTER),
+    WITHER(ABSTRACT_MONSTER),
+    BREEZE(ABSTRACT_MONSTER),
+    ZOGLIN(ABSTRACT_MONSTER),
+    WARDEN(ABSTRACT_MONSTER),
+    CREAKING(ABSTRACT_MONSTER),
+
+    ABSTRACT_SKELETON(ABSTRACT_MONSTER, null),
+    SKELETON(ABSTRACT_SKELETON),
+    STRAY(ABSTRACT_SKELETON),
+    WITHER_SKELETON(ABSTRACT_SKELETON),
+    BOGGED(ABSTRACT_SKELETON),
+
+    ZOMBIE(ABSTRACT_MONSTER),
+    DROWNED(ZOMBIE),
+    HUSK(ZOMBIE),
+    ZOMBIFIED_PIGLIN(ZOMBIE),
+    ZOMBIE_VILLAGER(ZOMBIE),
+
+    GUARDIAN(ABSTRACT_MONSTER),
+    ELDER_GUARDIAN(GUARDIAN),
+
+    SPIDER(ABSTRACT_MONSTER),
+    CAVE_SPIDER(SPIDER),
+
+    ABSTRACT_PIGLIN(ABSTRACT_MONSTER, null),
+    PIGLIN(ABSTRACT_PIGLIN),
+    PIGLIN_BRUTE(ABSTRACT_PIGLIN),
+
+    // Water mobs
+    AGEABLE_WATER_CREATURE(ABSTRACT_AGEABLE, null),
+    DOLPHIN(AGEABLE_WATER_CREATURE),
+
+    SQUID(AGEABLE_WATER_CREATURE),
+    GLOW_SQUID(SQUID),
+
+    WATER_ANIMAL(PATHFINDER_MOB, null),
+    ABSTRACT_FISH(WATER_ANIMAL, null),
+    PUFFERFISH(ABSTRACT_FISH),
+    TADPOLE(ABSTRACT_FISH),
+
+    ABSTRACT_SCHOOLING_FISH(ABSTRACT_FISH, null),
+    COD(ABSTRACT_SCHOOLING_FISH),
+    SALMON(ABSTRACT_SCHOOLING_FISH),
+    TROPICAL_FISH(ABSTRACT_SCHOOLING_FISH),
+
+    // Raiders
+    ABSTRACT_RAIDER(ABSTRACT_MONSTER, null),
+    WITCH(ABSTRACT_RAIDER),
+    RAVAGER(ABSTRACT_RAIDER),
+
+    ABSTRACT_ILLAGER(ABSTRACT_RAIDER, null),
+    SPELLCASTER_ILLAGER(ABSTRACT_ILLAGER, null),
+    VINDICATOR(ABSTRACT_ILLAGER),
+    PILLAGER(ABSTRACT_ILLAGER),
+    EVOKER(SPELLCASTER_ILLAGER),
+    ILLUSIONER(SPELLCASTER_ILLAGER);
+
+    private static final EntityType[] TYPES = EntityTypeUtil.createSizedArray(values());
+    private final EntityType parent;
+    private final String identifier;
+    private int id = -1;
+
+    EntityTypes1_21_5(final EntityType parent) {
+        this.parent = parent;
+        this.identifier = Key.namespaced(name().toLowerCase(Locale.ROOT));
+    }
+
+    EntityTypes1_21_5(final EntityType parent, @Nullable final String identifier) {
+        this.parent = parent;
+        this.identifier = identifier;
+    }
+
+    @Override
+    public int getId() {
+        if (id == -1) {
+            throw new IllegalStateException("Ids have not been initialized yet (type " + name() + ")");
+        }
+        return id;
+    }
+
+    @Override
+    public String identifier() {
+        Preconditions.checkArgument(identifier != null, "Called identifier method on abstract type");
+        return identifier;
+    }
+
+    @Override
+    public @Nullable EntityType getParent() {
+        return parent;
+    }
+
+    @Override
+    public boolean isAbstractType() {
+        return identifier == null;
+    }
+
+    public static EntityType getTypeFromId(final int typeId) {
+        return EntityTypeUtil.getTypeFromId(TYPES, typeId, PIG);
+    }
+
+    public static void initialize(final Protocol<?, ?, ?, ?> protocol) {
+        EntityTypeUtil.initialize(values(), TYPES, protocol, (type, id) -> type.id = id);
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/EntityTypes1_8.java

@@ -27,17 +27,6 @@ import java.util.Map;
 
 public class EntityTypes1_8 {
 
-    public static EntityType getTypeFromId(final int typeId, final boolean object) {
-        EntityType type;
-
-        if (object) {
-            type = ObjectType.getEntityType(typeId);
-        } else {
-            type = EntityType.findById(typeId);
-        }
-        return type;
-    }
-
     public enum EntityType implements com.viaversion.viaversion.api.minecraft.entities.EntityType {
 
         ENTITY,
@@ -203,7 +192,13 @@ public class EntityTypes1_8 {
     public enum ObjectType implements com.viaversion.viaversion.api.minecraft.entities.ObjectType {
         BOAT(1, EntityType.BOAT),
         ITEM(2, EntityType.ITEM),
-        MINECART(10, EntityType.MINECART), // There are multiple types, but we don't need them
+        MINECART(10, EntityType.MINECART),
+        CHEST_MINECART(10, 1, EntityType.CHEST_MINECART),
+        FURNACE_MINECART(10, 2, EntityType.FURNACE_MINECART),
+        TNT_MINECART(10, 3, EntityType.TNT_MINECART),
+        SPAWNER_MINECART(10, 4, EntityType.SPAWNER_MINECART),
+        HOPPER_MINECART(10, 5, EntityType.HOPPER_MINECART),
+        COMMAND_BLOCK_MINECART(10, 6, EntityType.COMMAND_BLOCK_MINECART),
         TNT_PRIMED(50, EntityType.TNT),
         ENDER_CRYSTAL(51, EntityType.END_CRYSTAL),
         TIPPED_ARROW(60, EntityType.ARROW),
@@ -223,19 +218,25 @@ public class EntityTypes1_8 {
         ARMOR_STAND(78, EntityType.ARMOR_STAND),
         FISHIHNG_HOOK(90, EntityType.FISHING_HOOK);
 
-        private static final Map<Integer, ObjectType> TYPES = new HashMap<>();
+        private static final Map<Integer, Map<Integer, ObjectType>> TYPES = new HashMap<>();
 
         private final int id;
+        private final int data;
         private final EntityType type;
 
         static {
             for (ObjectType type : ObjectType.values()) {
-                TYPES.put(type.id, type);
+                TYPES.computeIfAbsent(type.id, k -> new HashMap<>()).put(type.data, type);
             }
         }
 
         ObjectType(int id, EntityType type) {
+            this(id, 0, type);
+        }
+
+        ObjectType(int id, int data, EntityType type) {
             this.id = id;
+            this.data = data;
             this.type = type;
         }
 
@@ -244,20 +245,28 @@ public class EntityTypes1_8 {
             return id;
         }
 
+        @Override
+        public int getData() {
+            return data;
+        }
+
         @Override
         public EntityType getType() {
             return type;
         }
 
-        public static ObjectType findById(final int id) {
-            if (id == -1) {
+        public static ObjectType findById(final int id, final int data) {
+            final Map<Integer, ObjectType> types = TYPES.get(id);
+            if (types == null) {
                 return null;
             }
-            return TYPES.get(id);
+
+            final ObjectType type = types.get(data);
+            return type != null ? type : types.get(0);
         }
 
-        public static EntityType getEntityType(final int id) {
-            final ObjectType objectType = findById(id);
+        public static EntityType getEntityType(final int id, final int data) {
+            final ObjectType objectType = findById(id, data);
             return objectType != null ? objectType.type : null;
         }
     }

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/EntityTypes1_9.java

@@ -27,17 +27,6 @@ import java.util.Map;
 
 public class EntityTypes1_9 {
 
-    public static EntityType getTypeFromId(final int typeId, final boolean object) {
-        EntityType type;
-
-        if (object) {
-            type = ObjectType.getEntityType(typeId);
-        } else {
-            type = EntityType.findById(typeId);
-        }
-        return type;
-    }
-
     public enum EntityType implements com.viaversion.viaversion.api.minecraft.entities.EntityType {
 
         ENTITY,
@@ -211,7 +200,13 @@ public class EntityTypes1_9 {
         BOAT(1, EntityType.BOAT),
         ITEM(2, EntityType.ITEM),
         AREA_EFFECT_CLOUD(3, EntityType.AREA_EFFECT_CLOUD),
-        MINECART(10, EntityType.MINECART), // There are multiple types, but we don't need them
+        MINECART(10, EntityType.MINECART),
+        CHEST_MINECART(10, 1, EntityType.CHEST_MINECART),
+        FURNACE_MINECART(10, 2, EntityType.FURNACE_MINECART),
+        TNT_MINECART(10, 3, EntityType.TNT_MINECART),
+        SPAWNER_MINECART(10, 4, EntityType.SPAWNER_MINECART),
+        HOPPER_MINECART(10, 5, EntityType.HOPPER_MINECART),
+        COMMAND_BLOCK_MINECART(10, 6, EntityType.COMMAND_BLOCK_MINECART),
         TNT_PRIMED(50, EntityType.TNT),
         ENDER_CRYSTAL(51, EntityType.END_CRYSTAL),
         TIPPED_ARROW(60, EntityType.ARROW),
@@ -234,19 +229,25 @@ public class EntityTypes1_9 {
         SPECTRAL_ARROW(91, EntityType.SPECTRAL_ARROW),
         DRAGON_FIREBALL(93, EntityType.DRAGON_FIREBALL);
 
-        private static final Map<Integer, ObjectType> TYPES = new HashMap<>();
+        private static final Map<Integer, Map<Integer, ObjectType>> TYPES = new HashMap<>();
 
         private final int id;
+        private final int data;
         private final EntityType type;
 
         static {
             for (ObjectType type : ObjectType.values()) {
-                TYPES.put(type.id, type);
+                TYPES.computeIfAbsent(type.id, k -> new HashMap<>()).put(type.data, type);
             }
         }
 
         ObjectType(int id, EntityType type) {
+            this(id, 0, type);
+        }
+
+        ObjectType(int id, int data, EntityType type) {
             this.id = id;
+            this.data = data;
             this.type = type;
         }
 
@@ -255,20 +256,28 @@ public class EntityTypes1_9 {
             return id;
         }
 
+        @Override
+        public int getData() {
+            return data;
+        }
+
         @Override
         public EntityType getType() {
             return type;
         }
 
-        public static ObjectType findById(final int id) {
-            if (id == -1) {
+        public static ObjectType findById(final int id, final int data) {
+            final Map<Integer, ObjectType> types = TYPES.get(id);
+            if (types == null) {
                 return null;
             }
-            return TYPES.get(id);
+
+            final ObjectType type = types.get(data);
+            return type != null ? type : types.get(0);
         }
 
-        public static EntityType getEntityType(final int id) {
-            final ObjectType objectType = findById(id);
+        public static EntityType getEntityType(final int id, final int data) {
+            final ObjectType objectType = findById(id, data);
             return objectType != null ? objectType.type : null;
         }
     }

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/ObjectType.java

@@ -29,5 +29,7 @@ public interface ObjectType {
 
     int getId();
 
+    int getData();
+
     EntityType getType();
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/entitydata/types/EntityDataTypes1_21_5.java

@@ -0,0 +1,77 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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.entitydata.EntityDataType;
+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.misc.ParticleType;
+
+public final class EntityDataTypes1_21_5 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;
+    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 cowVariantType = add(23, Types.VAR_INT);
+    public final EntityDataType wolfVariantType = add(24, Types.VAR_INT);
+    public final EntityDataType wolfSoundVariantType = add(25, Types.VAR_INT);
+    public final EntityDataType frogVariantType = add(26, Types.VAR_INT);
+    public final EntityDataType pigVariantType = add(27, Types.VAR_INT);
+    public final EntityDataType chickenVariantType = add(28, Types.VAR_INT);
+    public final EntityDataType optionalGlobalPosition = add(29, Types.OPTIONAL_GLOBAL_POSITION);
+    public final EntityDataType paintingVariantType = add(30, PaintingVariant.TYPE1_21_2);
+    public final EntityDataType snifferState = add(31, Types.VAR_INT);
+    public final EntityDataType armadilloState = add(32, Types.VAR_INT);
+    public final EntityDataType vector3FType = add(33, Types.VECTOR3F);
+    public final EntityDataType quaternionType = add(34, Types.QUATERNION);
+
+    public EntityDataTypes1_21_5(final Type<Item> itemType, final ParticleType particleType, final Type<Particle[]> particlesType) {
+        super(35);
+        this.itemType = add(7, itemType);
+        this.particleType = add(17, particleType);
+        this.particlesType = add(18, particlesType);
+    }
+}

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

@@ -0,0 +1,42 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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;
+
+import it.unimi.dsi.fastutil.ints.Int2IntMap;
+import it.unimi.dsi.fastutil.ints.IntSet;
+
+/**
+ * Item that does not hold any real data outside of its id and amount.
+ * Instead, it holds hashes of added data and a set of keys of removed data.
+ * <p>
+ * This stores the raw int identifiers instead of data keys to simplify handling across protocols
+ * under the assumption that the keys are almost never needed beyond automated id updating.
+ *
+ * @see Item
+ */
+public interface HashedItem extends ItemBase {
+
+    Int2IntMap dataHashesById();
+
+    IntSet removedDataIds();
+}

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

@@ -0,0 +1,110 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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;
+
+import it.unimi.dsi.fastutil.ints.Int2IntMap;
+import it.unimi.dsi.fastutil.ints.Int2IntOpenHashMap;
+import it.unimi.dsi.fastutil.ints.IntOpenHashSet;
+import it.unimi.dsi.fastutil.ints.IntSet;
+
+public class HashedStructuredItem implements HashedItem {
+    private final Int2IntMap dataHashes;
+    private final IntSet removedData;
+    private int identifier;
+    private int amount;
+
+    public HashedStructuredItem(final int identifier, final int amount) {
+        this(identifier, amount, new Int2IntOpenHashMap(0), new IntOpenHashSet(0));
+    }
+
+    public HashedStructuredItem(final int identifier, final int amount, final Int2IntMap dataHashes, final IntSet removedData) {
+        this.identifier = identifier;
+        this.amount = amount;
+        this.dataHashes = dataHashes;
+        this.removedData = removedData;
+    }
+
+    public static HashedStructuredItem empty() {
+        // Data is mutable, create a new item
+        return new HashedStructuredItem(0, 0);
+    }
+
+    @Override
+    public int identifier() {
+        return this.identifier;
+    }
+
+    @Override
+    public void setIdentifier(final int identifier) {
+        this.identifier = identifier;
+    }
+
+    @Override
+    public int amount() {
+        return this.amount;
+    }
+
+    @Override
+    public void setAmount(final int amount) {
+        this.amount = amount;
+    }
+
+    @Override
+    public Int2IntMap dataHashesById() {
+        return this.dataHashes;
+    }
+
+    @Override
+    public IntSet removedDataIds() {
+        return this.removedData;
+    }
+
+    @Override
+    public boolean equals(final Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        final HashedStructuredItem that = (HashedStructuredItem) o;
+        if (identifier != that.identifier) return false;
+        if (amount != that.amount) return false;
+        return dataHashes.equals(that.dataHashes) && removedData.equals(that.removedData);
+    }
+
+    @Override
+    public int hashCode() {
+        int result = dataHashes.hashCode();
+        result = 31 * result + removedData.hashCode();
+        result = 31 * result + identifier;
+        result = 31 * result + amount;
+        return result;
+    }
+
+    @Override
+    public String toString() {
+        return "HashedStructuredItem{" +
+            "data=Hashes" + dataHashes +
+            ", removedData=" + removedData +
+            ", identifier=" + identifier +
+            ", amount=" + amount +
+            '}';
+    }
+}

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

@@ -24,37 +24,10 @@ package com.viaversion.viaversion.api.minecraft.item;
 
 import com.viaversion.nbt.tag.CompoundTag;
 import com.viaversion.viaversion.api.minecraft.data.StructuredDataContainer;
+import com.viaversion.viaversion.util.Copyable;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
-public interface Item {
-
-    /**
-     * Returns the item identifier.
-     *
-     * @return item identifier
-     */
-    int identifier();
-
-    /**
-     * Sets the item identifier.
-     *
-     * @param identifier item identifier
-     */
-    void setIdentifier(int identifier);
-
-    /**
-     * Returns the item amount.
-     *
-     * @return item amount
-     */
-    int amount();
-
-    /**
-     * Returns the item amount.
-     *
-     * @param amount item amount
-     */
-    void setAmount(int amount);
+public interface Item extends ItemBase, Copyable {
 
     /**
      * Returns the item data. Always 0 for 1.13+ items.
@@ -102,14 +75,6 @@ public interface Item {
      *
      * @return copy of the item
      */
+    @Override
     Item copy();
-
-    /**
-     * Returns true if the item is empty.
-     *
-     * @return true if the item is empty
-     */
-    default boolean isEmpty() {
-        return identifier() == 0 || amount() <= 0;
-    }
 }

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

@@ -0,0 +1,67 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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;
+
+/**
+ * @see Item
+ * @see HashedItem
+ */
+public interface ItemBase {
+
+    /**
+     * Returns the item identifier.
+     *
+     * @return item identifier
+     */
+    int identifier();
+
+    /**
+     * Sets the item identifier.
+     *
+     * @param identifier item identifier
+     */
+    void setIdentifier(int identifier);
+
+    /**
+     * Returns the item amount.
+     *
+     * @return item amount
+     */
+    int amount();
+
+    /**
+     * Returns the item amount.
+     *
+     * @param amount item amount
+     */
+    void setAmount(int amount);
+
+    /**
+     * Returns true if the item is empty.
+     *
+     * @return true if the item is empty
+     */
+    default boolean isEmpty() {
+        return identifier() == 0 || amount() <= 0;
+    }
+}

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

@@ -22,27 +22,54 @@
  */
 package com.viaversion.viaversion.api.minecraft.item.data;
 
+import com.viaversion.viaversion.api.minecraft.data.StructuredData;
 import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.types.ArrayType;
+import com.viaversion.viaversion.util.Copyable;
 import io.netty.buffer.ByteBuf;
 import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 
-public record AdventureModePredicate(BlockPredicate[] predicates, boolean showInTooltip) {
+public record AdventureModePredicate(BlockPredicate[] predicates, boolean showInTooltip) implements Copyable {
 
-    public static final Type<AdventureModePredicate> TYPE = new Type<>(AdventureModePredicate.class) {
+    public AdventureModePredicate(final BlockPredicate[] predicates) {
+        this(predicates, true);
+    }
+
+    public static final Type<AdventureModePredicate> TYPE1_20_5 = new Type<>(AdventureModePredicate.class) {
         @Override
         public AdventureModePredicate read(final ByteBuf buffer) {
-            final BlockPredicate[] predicates = BlockPredicate.ARRAY_TYPE.read(buffer);
+            final BlockPredicate[] predicates = BlockPredicate.ARRAY_TYPE1_20_5.read(buffer);
             final boolean showInTooltip = buffer.readBoolean();
             return new AdventureModePredicate(predicates, showInTooltip);
         }
 
         @Override
         public void write(final ByteBuf buffer, final AdventureModePredicate value) {
-            BlockPredicate.ARRAY_TYPE.write(buffer, value.predicates);
+            BlockPredicate.ARRAY_TYPE1_20_5.write(buffer, value.predicates);
             buffer.writeBoolean(value.showInTooltip);
         }
     };
 
+    public static final class AdventureModePredicateType1_21_5 extends Type<AdventureModePredicate> {
+        private final Type<BlockPredicate[]> blockPredicateType;
+
+        public AdventureModePredicateType1_21_5(final Type<StructuredData<?>[]> dataArrayType) {
+            super(AdventureModePredicate.class);
+            this.blockPredicateType = new ArrayType<>(new BlockPredicate.BlockPredicateType1_21_5(dataArrayType));
+        }
+
+        @Override
+        public AdventureModePredicate read(final ByteBuf buffer) {
+            final BlockPredicate[] predicates = blockPredicateType.read(buffer);
+            return new AdventureModePredicate(predicates);
+        }
+
+        @Override
+        public void write(final ByteBuf buffer, final AdventureModePredicate value) {
+            blockPredicateType.write(buffer, value.predicates);
+        }
+    }
+
     public AdventureModePredicate rewrite(final Int2IntFunction blockIdRewriter) {
         final BlockPredicate[] predicates = new BlockPredicate[this.predicates.length];
         for (int i = 0; i < predicates.length; i++) {
@@ -50,4 +77,9 @@ public record AdventureModePredicate(BlockPredicate[] predicates, boolean showIn
         }
         return new AdventureModePredicate(predicates, showInTooltip);
     }
+
+    @Override
+    public AdventureModePredicate copy() {
+        return new AdventureModePredicate(copy(predicates), showInTooltip);
+    }
 }

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

@@ -29,11 +29,15 @@ import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 
 public record ArmorTrim(Holder<ArmorTrimMaterial> material, Holder<ArmorTrimPattern> pattern, boolean showInTooltip) {
 
+    public ArmorTrim(Holder<ArmorTrimMaterial> material, Holder<ArmorTrimPattern> pattern) {
+        this(material, pattern, true);
+    }
+
     public static final Type<ArmorTrim> TYPE1_20_5 = new Type<>(ArmorTrim.class) {
         @Override
         public ArmorTrim read(final ByteBuf buffer) {
             final Holder<ArmorTrimMaterial> material = ArmorTrimMaterial.TYPE1_20_5.read(buffer);
-            final Holder<ArmorTrimPattern> pattern = ArmorTrimPattern.TYPE.read(buffer);
+            final Holder<ArmorTrimPattern> pattern = ArmorTrimPattern.TYPE1_20_5.read(buffer);
             final boolean showInTooltip = buffer.readBoolean();
             return new ArmorTrim(material, pattern, showInTooltip);
         }
@@ -41,7 +45,7 @@ public record ArmorTrim(Holder<ArmorTrimMaterial> material, Holder<ArmorTrimPatt
         @Override
         public void write(final ByteBuf buffer, final ArmorTrim value) {
             ArmorTrimMaterial.TYPE1_20_5.write(buffer, value.material);
-            ArmorTrimPattern.TYPE.write(buffer, value.pattern);
+            ArmorTrimPattern.TYPE1_20_5.write(buffer, value.pattern);
             buffer.writeBoolean(value.showInTooltip);
         }
     };
@@ -49,7 +53,7 @@ public record ArmorTrim(Holder<ArmorTrimMaterial> material, Holder<ArmorTrimPatt
         @Override
         public ArmorTrim read(final ByteBuf buffer) {
             final Holder<ArmorTrimMaterial> material = ArmorTrimMaterial.TYPE1_21_2.read(buffer);
-            final Holder<ArmorTrimPattern> pattern = ArmorTrimPattern.TYPE.read(buffer);
+            final Holder<ArmorTrimPattern> pattern = ArmorTrimPattern.TYPE1_20_5.read(buffer);
             final boolean showInTooltip = buffer.readBoolean();
             return new ArmorTrim(material, pattern, showInTooltip);
         }
@@ -57,7 +61,7 @@ public record ArmorTrim(Holder<ArmorTrimMaterial> material, Holder<ArmorTrimPatt
         @Override
         public void write(final ByteBuf buffer, final ArmorTrim value) {
             ArmorTrimMaterial.TYPE1_21_2.write(buffer, value.material);
-            ArmorTrimPattern.TYPE.write(buffer, value.pattern);
+            ArmorTrimPattern.TYPE1_20_5.write(buffer, value.pattern);
             buffer.writeBoolean(value.showInTooltip);
         }
     };
@@ -65,7 +69,7 @@ public record ArmorTrim(Holder<ArmorTrimMaterial> material, Holder<ArmorTrimPatt
         @Override
         public ArmorTrim read(final ByteBuf buffer) {
             final Holder<ArmorTrimMaterial> material = ArmorTrimMaterial.TYPE1_21_4.read(buffer);
-            final Holder<ArmorTrimPattern> pattern = ArmorTrimPattern.TYPE.read(buffer);
+            final Holder<ArmorTrimPattern> pattern = ArmorTrimPattern.TYPE1_20_5.read(buffer);
             final boolean showInTooltip = buffer.readBoolean();
             return new ArmorTrim(material, pattern, showInTooltip);
         }
@@ -73,10 +77,24 @@ public record ArmorTrim(Holder<ArmorTrimMaterial> material, Holder<ArmorTrimPatt
         @Override
         public void write(final ByteBuf buffer, final ArmorTrim value) {
             ArmorTrimMaterial.TYPE1_21_4.write(buffer, value.material);
-            ArmorTrimPattern.TYPE.write(buffer, value.pattern);
+            ArmorTrimPattern.TYPE1_20_5.write(buffer, value.pattern);
             buffer.writeBoolean(value.showInTooltip);
         }
     };
+    public static final Type<ArmorTrim> TYPE1_21_5 = new Type<>(ArmorTrim.class) {
+        @Override
+        public ArmorTrim read(final ByteBuf buffer) {
+            final Holder<ArmorTrimMaterial> material = ArmorTrimMaterial.TYPE1_21_5.read(buffer);
+            final Holder<ArmorTrimPattern> pattern = ArmorTrimPattern.TYPE1_21_5.read(buffer);
+            return new ArmorTrim(material, pattern);
+        }
+
+        @Override
+        public void write(final ByteBuf buffer, final ArmorTrim value) {
+            ArmorTrimMaterial.TYPE1_21_5.write(buffer, value.material);
+            ArmorTrimPattern.TYPE1_21_5.write(buffer, value.pattern);
+        }
+    };
 
     public ArmorTrim rewrite(final Int2IntFunction idRewriteFunction) {
         Holder<ArmorTrimMaterial> material = this.material;

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

@@ -25,18 +25,23 @@ package com.viaversion.viaversion.api.minecraft.item.data;
 import com.viaversion.nbt.tag.Tag;
 import com.viaversion.viaversion.api.type.Types;
 import com.viaversion.viaversion.api.type.types.misc.HolderType;
+import com.viaversion.viaversion.util.Copyable;
 import io.netty.buffer.ByteBuf;
 import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 import it.unimi.dsi.fastutil.objects.Object2ObjectArrayMap;
 import java.util.Map;
 
 public record ArmorTrimMaterial(String assetName, int itemId, float itemModelIndex,
-                                Map<String, String> overrideArmorMaterials, Tag description) {
+                                Map<String, String> overrideArmorMaterials, Tag description) implements Copyable {
 
     public ArmorTrimMaterial(final String assetName, final int itemId, final Map<String, String> overrideArmorMaterials, final Tag description) {
         this(assetName, itemId, 0F, overrideArmorMaterials, description);
     }
 
+    public ArmorTrimMaterial(final String assetName, final Map<String, String> overrideArmorMaterials, final Tag description) {
+        this(assetName, 0, 0F, overrideArmorMaterials, description);
+    }
+
     public static final HolderType<ArmorTrimMaterial> TYPE1_20_5 = new HolderType<>() {
         // The override key is an int, but given we don't use it at all and that creating a new type is annoying,
         // we'll just store it in the string map:tm:
@@ -47,7 +52,7 @@ public record ArmorTrimMaterial(String assetName, int itemId, float itemModelInd
             final float itemModelIndex = buffer.readFloat();
 
             final int overrideArmorMaterialsSize = Types.VAR_INT.readPrimitive(buffer);
-            final Map<String, String> overrideArmorMaterials = new Object2ObjectArrayMap<>(overrideArmorMaterialsSize);
+            final Map<String, String> overrideArmorMaterials = new Object2ObjectArrayMap<>();
             for (int i = 0; i < overrideArmorMaterialsSize; i++) {
                 final int key = Types.VAR_INT.readPrimitive(buffer);
                 final String value = Types.STRING.read(buffer);
@@ -73,7 +78,6 @@ public record ArmorTrimMaterial(String assetName, int itemId, float itemModelInd
             Types.TAG.write(buffer, value.description());
         }
     };
-
     public static final HolderType<ArmorTrimMaterial> TYPE1_21_2 = new HolderType<>() {
         @Override
         public ArmorTrimMaterial readDirect(final ByteBuf buffer) {
@@ -82,7 +86,7 @@ public record ArmorTrimMaterial(String assetName, int itemId, float itemModelInd
             final float itemModelIndex = buffer.readFloat();
 
             final int overrideArmorMaterialsSize = Types.VAR_INT.readPrimitive(buffer);
-            final Map<String, String> overrideArmorMaterials = new Object2ObjectArrayMap<>(overrideArmorMaterialsSize);
+            final Map<String, String> overrideArmorMaterials = new Object2ObjectArrayMap<>();
             for (int i = 0; i < overrideArmorMaterialsSize; i++) {
                 final String key = Types.STRING.read(buffer);
                 final String value = Types.STRING.read(buffer);
@@ -108,7 +112,6 @@ public record ArmorTrimMaterial(String assetName, int itemId, float itemModelInd
             Types.TAG.write(buffer, value.description());
         }
     };
-
     public static final HolderType<ArmorTrimMaterial> TYPE1_21_4 = new HolderType<>() {
         @Override
         public ArmorTrimMaterial readDirect(final ByteBuf buffer) {
@@ -116,7 +119,7 @@ public record ArmorTrimMaterial(String assetName, int itemId, float itemModelInd
             final int item = Types.VAR_INT.readPrimitive(buffer);
 
             final int overrideArmorMaterialsSize = Types.VAR_INT.readPrimitive(buffer);
-            final Map<String, String> overrideArmorMaterials = new Object2ObjectArrayMap<>(overrideArmorMaterialsSize);
+            final Map<String, String> overrideArmorMaterials = new Object2ObjectArrayMap<>();
             for (int i = 0; i < overrideArmorMaterialsSize; i++) {
                 final String key = Types.STRING.read(buffer);
                 final String value = Types.STRING.read(buffer);
@@ -141,8 +144,43 @@ public record ArmorTrimMaterial(String assetName, int itemId, float itemModelInd
             Types.TAG.write(buffer, value.description());
         }
     };
+    public static final HolderType<ArmorTrimMaterial> TYPE1_21_5 = new HolderType<>() {
+        @Override
+        public ArmorTrimMaterial readDirect(final ByteBuf buffer) {
+            final String assetName = Types.STRING.read(buffer);
+
+            final int overrideArmorMaterialsSize = Types.VAR_INT.readPrimitive(buffer);
+            final Map<String, String> overrideArmorMaterials = new Object2ObjectArrayMap<>();
+            for (int i = 0; i < overrideArmorMaterialsSize; i++) {
+                final String key = Types.STRING.read(buffer);
+                final String value = Types.STRING.read(buffer);
+                overrideArmorMaterials.put(key, value);
+            }
+
+            final Tag description = Types.TAG.read(buffer);
+            return new ArmorTrimMaterial(assetName, overrideArmorMaterials, description);
+        }
+
+        @Override
+        public void writeDirect(final ByteBuf buffer, final ArmorTrimMaterial value) {
+            Types.STRING.write(buffer, value.assetName());
+
+            Types.VAR_INT.writePrimitive(buffer, value.overrideArmorMaterials().size());
+            for (final Map.Entry<String, String> entry : value.overrideArmorMaterials().entrySet()) {
+                Types.STRING.write(buffer, entry.getKey());
+                Types.STRING.write(buffer, entry.getValue());
+            }
+
+            Types.TAG.write(buffer, value.description());
+        }
+    };
 
     public ArmorTrimMaterial rewrite(final Int2IntFunction idRewriteFunction) {
         return new ArmorTrimMaterial(assetName, idRewriteFunction.applyAsInt(itemId), itemModelIndex, overrideArmorMaterials, description);
     }
+
+    @Override
+    public ArmorTrimMaterial copy() {
+        return new ArmorTrimMaterial(assetName, itemId, itemModelIndex, new Object2ObjectArrayMap<>(overrideArmorMaterials), description);
+    }
 }

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

@@ -25,12 +25,17 @@ package com.viaversion.viaversion.api.minecraft.item.data;
 import com.viaversion.nbt.tag.Tag;
 import com.viaversion.viaversion.api.type.Types;
 import com.viaversion.viaversion.api.type.types.misc.HolderType;
+import com.viaversion.viaversion.util.Copyable;
 import io.netty.buffer.ByteBuf;
 import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 
-public record ArmorTrimPattern(String assetName, int itemId, Tag description, boolean decal) {
+public record ArmorTrimPattern(String assetName, int itemId, Tag description, boolean decal) implements Copyable {
 
-    public static final HolderType<ArmorTrimPattern> TYPE = new HolderType<>() {
+    public ArmorTrimPattern(final String assetName, final Tag description, final boolean decal) {
+        this(assetName, 0, description, decal);
+    }
+
+    public static final HolderType<ArmorTrimPattern> TYPE1_20_5 = new HolderType<>() {
         @Override
         public ArmorTrimPattern readDirect(final ByteBuf buffer) {
             final String assetName = Types.STRING.read(buffer);
@@ -48,8 +53,29 @@ public record ArmorTrimPattern(String assetName, int itemId, Tag description, bo
             buffer.writeBoolean(value.decal());
         }
     };
+    public static final HolderType<ArmorTrimPattern> TYPE1_21_5 = new HolderType<>() {
+        @Override
+        public ArmorTrimPattern readDirect(final ByteBuf buffer) {
+            final String assetName = Types.STRING.read(buffer);
+            final Tag description = Types.TAG.read(buffer);
+            final boolean decal = buffer.readBoolean();
+            return new ArmorTrimPattern(assetName, description, decal);
+        }
+
+        @Override
+        public void writeDirect(final ByteBuf buffer, final ArmorTrimPattern value) {
+            Types.STRING.write(buffer, value.assetName());
+            Types.TAG.write(buffer, value.description());
+            buffer.writeBoolean(value.decal());
+        }
+    };
 
     public ArmorTrimPattern rewrite(final Int2IntFunction idRewriteFunction) {
         return new ArmorTrimPattern(assetName, idRewriteFunction.applyAsInt(itemId), description, decal);
     }
+
+    @Override
+    public ArmorTrimPattern copy() {
+        return new ArmorTrimPattern(assetName, itemId, description.copy(), decal);
+    }
 }

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

@@ -25,10 +25,11 @@ 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 com.viaversion.viaversion.util.Copyable;
 import io.netty.buffer.ByteBuf;
 import java.util.UUID;
 
-public record AttributeModifiers1_20_5(AttributeModifier[] modifiers, boolean showInTooltip) {
+public record AttributeModifiers1_20_5(AttributeModifier[] modifiers, boolean showInTooltip) implements Copyable {
 
     public static final Type<AttributeModifiers1_20_5> TYPE = new Type<>(AttributeModifiers1_20_5.class) {
         @Override
@@ -45,6 +46,11 @@ public record AttributeModifiers1_20_5(AttributeModifier[] modifiers, boolean sh
         }
     };
 
+    @Override
+    public AttributeModifiers1_20_5 copy() {
+        return new AttributeModifiers1_20_5(copy(modifiers), showInTooltip);
+    }
+
     public record AttributeModifier(int attribute, ModifierData modifier, int slotType) {
 
         public static final Type<AttributeModifier> TYPE = new Type<>(AttributeModifier.class) {

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

@@ -25,12 +25,17 @@ 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 com.viaversion.viaversion.util.Copyable;
 import io.netty.buffer.ByteBuf;
 import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 
-public record AttributeModifiers1_21(AttributeModifier[] modifiers, boolean showInTooltip) {
+public record AttributeModifiers1_21(AttributeModifier[] modifiers, boolean showInTooltip) implements Copyable {
 
-    public static final Type<AttributeModifiers1_21> TYPE = new Type<>(AttributeModifiers1_21.class) {
+    public AttributeModifiers1_21(final AttributeModifier[] modifiers) {
+        this(modifiers, true);
+    }
+
+    public static final Type<AttributeModifiers1_21> TYPE1_21 = new Type<>(AttributeModifiers1_21.class) {
         @Override
         public AttributeModifiers1_21 read(final ByteBuf buffer) {
             final AttributeModifier[] modifiers = AttributeModifier.ARRAY_TYPE.read(buffer);
@@ -44,6 +49,18 @@ public record AttributeModifiers1_21(AttributeModifier[] modifiers, boolean show
             buffer.writeBoolean(value.showInTooltip());
         }
     };
+    public static final Type<AttributeModifiers1_21> TYPE1_21_5 = new Type<>(AttributeModifiers1_21.class) {
+        @Override
+        public AttributeModifiers1_21 read(final ByteBuf buffer) {
+            final AttributeModifier[] modifiers = AttributeModifier.ARRAY_TYPE.read(buffer);
+            return new AttributeModifiers1_21(modifiers);
+        }
+
+        @Override
+        public void write(final ByteBuf buffer, final AttributeModifiers1_21 value) {
+            AttributeModifier.ARRAY_TYPE.write(buffer, value.modifiers());
+        }
+    };
 
     public AttributeModifiers1_21 rewrite(final Int2IntFunction rewriteFunction) {
         final AttributeModifier[] modifiers = new AttributeModifier[this.modifiers.length];
@@ -54,6 +71,11 @@ public record AttributeModifiers1_21(AttributeModifier[] modifiers, boolean show
         return new AttributeModifiers1_21(modifiers, showInTooltip);
     }
 
+    @Override
+    public AttributeModifiers1_21 copy() {
+        return new AttributeModifiers1_21(copy(modifiers), showInTooltip);
+    }
+
     public record AttributeModifier(int attribute, ModifierData modifier, int slotType) {
 
         public static final Type<AttributeModifier> TYPE = new Type<>(AttributeModifier.class) {

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

@@ -26,9 +26,10 @@ import com.viaversion.nbt.tag.CompoundTag;
 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.util.Copyable;
 import io.netty.buffer.ByteBuf;
 
-public record Bee(CompoundTag entityData, int ticksInHive, int minTicksInHive) {
+public record Bee(CompoundTag entityData, int ticksInHive, int minTicksInHive) implements Copyable {
 
     public static final Type<Bee> TYPE = new Type<>(Bee.class) {
         @Override
@@ -48,4 +49,8 @@ public record Bee(CompoundTag entityData, int ticksInHive, int minTicksInHive) {
     };
     public static final Type<Bee[]> ARRAY_TYPE = new ArrayType<>(TYPE);
 
+    @Override
+    public Bee copy() {
+        return new Bee(entityData.copy(), ticksInHive, minTicksInHive);
+    }
 }

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

@@ -24,23 +24,31 @@ package com.viaversion.viaversion.api.minecraft.item.data;
 
 import com.viaversion.nbt.tag.CompoundTag;
 import com.viaversion.viaversion.api.minecraft.HolderSet;
+import com.viaversion.viaversion.api.minecraft.data.StructuredData;
+import com.viaversion.viaversion.api.minecraft.data.predicate.DataComponentMatchers;
+import com.viaversion.viaversion.api.minecraft.data.predicate.DataComponentMatchers.DataComponentMatchersType;
 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.util.Copyable;
 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,
-                             @Nullable CompoundTag tag) {
+                             @Nullable CompoundTag tag, DataComponentMatchers dataMatchers) implements Copyable {
 
-    public static final Type<BlockPredicate> TYPE = new Type<>(BlockPredicate.class) {
+    public BlockPredicate(@Nullable final HolderSet holderSet, final StatePropertyMatcher @Nullable [] propertyMatchers, @Nullable final CompoundTag tag) {
+        this(holderSet, propertyMatchers, tag, null);
+    }
+
+    public static final Type<BlockPredicate> TYPE1_20_5 = new Type<>(BlockPredicate.class) {
         @Override
         public BlockPredicate read(final ByteBuf buffer) {
             final HolderSet holders = Types.OPTIONAL_HOLDER_SET.read(buffer);
             final StatePropertyMatcher[] propertyMatchers = buffer.readBoolean() ? StatePropertyMatcher.ARRAY_TYPE.read(buffer) : null;
             final CompoundTag tag = Types.OPTIONAL_COMPOUND_TAG.read(buffer);
-            return new BlockPredicate(holders, propertyMatchers, tag);
+            return new BlockPredicate(holders, propertyMatchers, tag, null);
         }
 
         @Override
@@ -55,7 +63,38 @@ public record BlockPredicate(@Nullable HolderSet holderSet, StatePropertyMatcher
             Types.OPTIONAL_COMPOUND_TAG.write(buffer, value.tag);
         }
     };
-    public static final Type<BlockPredicate[]> ARRAY_TYPE = new ArrayType<>(TYPE);
+    public static final Type<BlockPredicate[]> ARRAY_TYPE1_20_5 = new ArrayType<>(TYPE1_20_5);
+
+    public static final class BlockPredicateType1_21_5 extends Type<BlockPredicate> {
+        private final Type<DataComponentMatchers> matchersType;
+
+        public BlockPredicateType1_21_5(final Type<StructuredData<?>[]> dataArrayType) {
+            super(BlockPredicate.class);
+            this.matchersType = new DataComponentMatchersType(dataArrayType);
+        }
+
+        @Override
+        public BlockPredicate read(final ByteBuf buffer) {
+            final HolderSet holders = Types.OPTIONAL_HOLDER_SET.read(buffer);
+            final StatePropertyMatcher[] propertyMatchers = buffer.readBoolean() ? StatePropertyMatcher.ARRAY_TYPE.read(buffer) : null;
+            final CompoundTag tag = Types.OPTIONAL_COMPOUND_TAG.read(buffer);
+            final DataComponentMatchers matchers = matchersType.read(buffer);
+            return new BlockPredicate(holders, propertyMatchers, tag, matchers);
+        }
+
+        @Override
+        public void write(final ByteBuf buffer, final BlockPredicate value) {
+            Types.OPTIONAL_HOLDER_SET.write(buffer, value.holderSet);
+
+            buffer.writeBoolean(value.propertyMatchers != null);
+            if (value.propertyMatchers != null) {
+                StatePropertyMatcher.ARRAY_TYPE.write(buffer, value.propertyMatchers);
+            }
+
+            Types.OPTIONAL_COMPOUND_TAG.write(buffer, value.tag);
+            matchersType.write(buffer, value.dataMatchers);
+        }
+    }
 
     public BlockPredicate rewrite(final Int2IntFunction blockIdRewriter) {
         if (holderSet == null || holderSet.hasTagKey()) {
@@ -65,4 +104,9 @@ public record BlockPredicate(@Nullable HolderSet holderSet, StatePropertyMatcher
         final HolderSet updatedHolders = holderSet.rewrite(blockIdRewriter);
         return new BlockPredicate(updatedHolders, propertyMatchers, tag);
     }
+
+    @Override
+    public BlockPredicate copy() {
+        return new BlockPredicate(holderSet, copy(propertyMatchers), tag == null ? null : tag.copy());
+    }
 }

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

@@ -24,17 +24,18 @@ 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.util.Copyable;
 import io.netty.buffer.ByteBuf;
 import it.unimi.dsi.fastutil.objects.Object2ObjectOpenHashMap;
 import java.util.Map;
 
-public record BlockStateProperties(Map<String, String> properties) {
+public record BlockStateProperties(Map<String, String> properties) implements Copyable {
 
     public static final Type<BlockStateProperties> TYPE = new Type<>(BlockStateProperties.class) {
         @Override
         public BlockStateProperties read(final ByteBuf buffer) {
             final int size = Types.VAR_INT.readPrimitive(buffer);
-            final Map<String, String> properties = new Object2ObjectOpenHashMap<>(size);
+            final Map<String, String> properties = new Object2ObjectOpenHashMap<>();
             for (int i = 0; i < size; i++) {
                 properties.put(Types.STRING.read(buffer), Types.STRING.read(buffer));
             }
@@ -51,4 +52,8 @@ public record BlockStateProperties(Map<String, String> properties) {
         }
     };
 
+    @Override
+    public BlockStateProperties copy() {
+        return new BlockStateProperties(new Object2ObjectOpenHashMap<>(properties));
+    }
 }

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

@@ -0,0 +1,114 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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.minecraft.Holder;
+import com.viaversion.viaversion.api.minecraft.HolderSet;
+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.ArrayType;
+import io.netty.buffer.ByteBuf;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+public record BlocksAttacks(
+    float blockDelaySeconds,
+    float disableCooldownScale,
+    DamageReduction[] damageReductions,
+    ItemDamageFunction itemDamage,
+    @Nullable String bypassedByTag,
+    @Nullable Holder<SoundEvent> blockSound,
+    @Nullable Holder<SoundEvent> disableSound
+) {
+
+    public static final Type<BlocksAttacks> TYPE = new Type<>(BlocksAttacks.class) {
+
+        @Override
+        public BlocksAttacks read(final ByteBuf buffer) {
+            final float blockDelaySeconds = buffer.readFloat();
+            final float disableCooldownScale = buffer.readFloat();
+            final DamageReduction[] damageReductions = DamageReduction.ARRAY_TYPE.read(buffer);
+            final ItemDamageFunction itemDamage = ItemDamageFunction.TYPE.read(buffer);
+            final String bypassedByTag = Types.OPTIONAL_STRING.read(buffer);
+            final Holder<SoundEvent> blockSound = Types.OPTIONAL_SOUND_EVENT.read(buffer);
+            final Holder<SoundEvent> disableSound = Types.OPTIONAL_SOUND_EVENT.read(buffer);
+            return new BlocksAttacks(blockDelaySeconds, disableCooldownScale, damageReductions, itemDamage, bypassedByTag, blockSound, disableSound);
+        }
+
+        @Override
+        public void write(final ByteBuf buffer, final BlocksAttacks value) {
+            buffer.writeFloat(value.blockDelaySeconds());
+            buffer.writeFloat(value.disableCooldownScale());
+            DamageReduction.ARRAY_TYPE.write(buffer, value.damageReductions());
+            ItemDamageFunction.TYPE.write(buffer, value.itemDamage());
+            Types.OPTIONAL_STRING.write(buffer, value.bypassedByTag());
+            Types.OPTIONAL_SOUND_EVENT.write(buffer, value.blockSound());
+            Types.OPTIONAL_SOUND_EVENT.write(buffer, value.disableSound());
+        }
+    };
+
+    public record DamageReduction(float horizontalBlockingAngle, @Nullable HolderSet type, float base, float factor) {
+
+        public static final Type<DamageReduction> TYPE = new Type<>(DamageReduction.class) {
+
+            @Override
+            public DamageReduction read(final ByteBuf buffer) {
+                final float horizontalBlockingAngle = buffer.readFloat();
+                final HolderSet type = Types.OPTIONAL_HOLDER_SET.read(buffer);
+                final float base = buffer.readFloat();
+                final float factor = buffer.readFloat();
+                return new DamageReduction(horizontalBlockingAngle, type, base, factor);
+            }
+
+            @Override
+            public void write(final ByteBuf buffer, final DamageReduction value) {
+                buffer.writeFloat(value.horizontalBlockingAngle());
+                Types.OPTIONAL_HOLDER_SET.write(buffer, value.type());
+                buffer.writeFloat(value.base());
+                buffer.writeFloat(value.factor());
+            }
+        };
+        public static final ArrayType<DamageReduction> ARRAY_TYPE = new ArrayType<>(TYPE);
+    }
+
+    public record ItemDamageFunction(float threshold, float base, float factor) {
+
+        public static final Type<ItemDamageFunction> TYPE = new Type<>(ItemDamageFunction.class) {
+
+            @Override
+            public ItemDamageFunction read(final ByteBuf buffer) {
+                final float threshold = buffer.readFloat();
+                final float base = buffer.readFloat();
+                final float factor = buffer.readFloat();
+                return new ItemDamageFunction(threshold, base, factor);
+            }
+
+            @Override
+            public void write(final ByteBuf buffer, final ItemDamageFunction value) {
+                buffer.writeFloat(value.threshold());
+                buffer.writeFloat(value.base());
+                buffer.writeFloat(value.factor());
+            }
+        };
+    }
+}

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

@@ -26,9 +26,10 @@ 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 com.viaversion.viaversion.util.Copyable;
 import io.netty.buffer.ByteBuf;
 
-public record ChatType(ChatTypeDecoration chatDecoration, ChatTypeDecoration narrationDecoration) {
+public record ChatType(ChatTypeDecoration chatDecoration, ChatTypeDecoration narrationDecoration) implements Copyable {
 
     public static final HolderType<ChatType> TYPE = new HolderType<>() {
         @Override
@@ -45,7 +46,12 @@ public record ChatType(ChatTypeDecoration chatDecoration, ChatTypeDecoration nar
         }
     };
 
-    public record ChatTypeDecoration(String translationKey, int[] parameters, Tag style) {
+    @Override
+    public ChatType copy() {
+        return new ChatType(chatDecoration.copy(), narrationDecoration.copy());
+    }
+
+    public record ChatTypeDecoration(String translationKey, int[] parameters, Tag style) implements Copyable {
 
         public static final Type<ChatTypeDecoration> TYPE = new Type<>(ChatTypeDecoration.class) {
 
@@ -64,5 +70,10 @@ public record ChatType(ChatTypeDecoration chatDecoration, ChatTypeDecoration nar
                 Types.TAG.write(buffer, value.style());
             }
         };
+
+        @Override
+        public ChatTypeDecoration copy() {
+            return new ChatTypeDecoration(translationKey, parameters.clone(), style.copy());
+        }
     }
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/Consumable1_21_2.java

@@ -27,10 +27,12 @@ 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.ArrayType;
+import com.viaversion.viaversion.util.Copyable;
 import io.netty.buffer.ByteBuf;
+import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 
 public record Consumable1_21_2(float consumeSeconds, int animationType, Holder<SoundEvent> sound,
-                               boolean hasConsumeParticles, ConsumeEffect<?>[] consumeEffects) {
+                               boolean hasConsumeParticles, ConsumeEffect<?>[] consumeEffects) implements Copyable {
 
     public static final Type<?>[] EFFECT_TYPES = {
         ApplyStatusEffects.TYPE,
@@ -108,4 +110,14 @@ public record Consumable1_21_2(float consumeSeconds, int animationType, Holder<S
             }
         };
     }
+
+    public Consumable1_21_2 rewrite(final Int2IntFunction soundIdRewriteFunction) {
+        final Holder<SoundEvent> soundHolder = this.sound.updateId(soundIdRewriteFunction);
+        return soundHolder == this.sound ? this : new Consumable1_21_2(consumeSeconds, animationType, soundHolder, hasConsumeParticles, consumeEffects);
+    }
+
+    @Override
+    public Consumable1_21_2 copy() {
+        return new Consumable1_21_2(consumeSeconds, animationType, sound, hasConsumeParticles, copy(consumeEffects));
+    }
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/CustomModelData1_21_4.java

@@ -24,9 +24,10 @@ 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.util.Copyable;
 import io.netty.buffer.ByteBuf;
 
-public record CustomModelData1_21_4(float[] floats, boolean[] booleans, String[] strings, int[] colors) {
+public record CustomModelData1_21_4(float[] floats, boolean[] booleans, String[] strings, int[] colors) implements Copyable {
 
     public static final Type<CustomModelData1_21_4> TYPE = new Type<>(CustomModelData1_21_4.class) {
         @Override
@@ -46,4 +47,9 @@ public record CustomModelData1_21_4(float[] floats, boolean[] booleans, String[]
             Types.INT_ARRAY_PRIMITIVE.write(buffer, value.colors());
         }
     };
+
+    @Override
+    public CustomModelData1_21_4 copy() {
+        return new CustomModelData1_21_4(copy(floats), copy(booleans), copy(strings), copy(colors));
+    }
 }

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

@@ -24,10 +24,10 @@ package com.viaversion.viaversion.api.minecraft.item.data;
 
 import com.viaversion.viaversion.api.minecraft.item.data.Consumable1_21_2.ConsumeEffect;
 import com.viaversion.viaversion.api.type.Type;
-import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.util.Copyable;
 import io.netty.buffer.ByteBuf;
 
-public record DeathProtection(ConsumeEffect<?>[] deathEffects) {
+public record DeathProtection(ConsumeEffect<?>[] deathEffects) implements Copyable {
 
     public static final Type<DeathProtection> TYPE = new Type<>(DeathProtection.class) {
         @Override
@@ -41,4 +41,9 @@ public record DeathProtection(ConsumeEffect<?>[] deathEffects) {
             ConsumeEffect.ARRAY_TYPE.write(buffer, value.deathEffects);
         }
     };
+
+    @Override
+    public DeathProtection copy() {
+        return new DeathProtection(copy(deathEffects));
+    }
 }

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

@@ -27,7 +27,11 @@ import io.netty.buffer.ByteBuf;
 
 public record DyedColor(int rgb, boolean showInTooltip) {
 
-    public static final Type<DyedColor> TYPE = new Type<>(DyedColor.class) {
+    public DyedColor(final int rgb) {
+        this(rgb, true);
+    }
+
+    public static final Type<DyedColor> TYPE1_20_5 = new Type<>(DyedColor.class) {
         @Override
         public DyedColor read(final ByteBuf buffer) {
             final int rgb = buffer.readInt();
@@ -41,5 +45,16 @@ public record DyedColor(int rgb, boolean showInTooltip) {
             buffer.writeBoolean(value.showInTooltip);
         }
     };
+    public static final Type<DyedColor> TYPE1_21_5 = new Type<>(DyedColor.class) {
+        @Override
+        public DyedColor read(final ByteBuf buffer) {
+            final int rgb = buffer.readInt();
+            return new DyedColor(rgb);
+        }
 
+        @Override
+        public void write(final ByteBuf buffer, final DyedColor value) {
+            buffer.writeInt(value.rgb);
+        }
+    };
 }

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

@@ -24,13 +24,18 @@ 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.util.Copyable;
 import io.netty.buffer.ByteBuf;
 import it.unimi.dsi.fastutil.ints.Int2IntMap;
 import it.unimi.dsi.fastutil.ints.Int2IntOpenHashMap;
 
-public record Enchantments(Int2IntMap enchantments, boolean showInTooltip) {
+public record Enchantments(Int2IntMap enchantments, boolean showInTooltip) implements Copyable {
 
-    public static final Type<Enchantments> TYPE = new Type<>(Enchantments.class) {
+    public Enchantments(final Int2IntMap enchantments) {
+        this(enchantments, true);
+    }
+
+    public static final Type<Enchantments> TYPE1_20_5 = new Type<>(Enchantments.class) {
         @Override
         public Enchantments read(final ByteBuf buffer) {
             final Int2IntMap enchantments = new Int2IntOpenHashMap();
@@ -54,6 +59,29 @@ public record Enchantments(Int2IntMap enchantments, boolean showInTooltip) {
             buffer.writeBoolean(value.showInTooltip());
         }
     };
+    public static final Type<Enchantments> TYPE1_21_5 = new Type<>(Enchantments.class) {
+        @Override
+        public Enchantments read(final ByteBuf buffer) {
+            final Int2IntMap enchantments = new Int2IntOpenHashMap();
+            final int size = Types.VAR_INT.readPrimitive(buffer);
+            for (int i = 0; i < size; i++) {
+                final int id = Types.VAR_INT.readPrimitive(buffer);
+                final int level = Types.VAR_INT.readPrimitive(buffer);
+                enchantments.put(id, level);
+            }
+
+            return new Enchantments(enchantments);
+        }
+
+        @Override
+        public void write(final ByteBuf buffer, final Enchantments value) {
+            Types.VAR_INT.writePrimitive(buffer, value.enchantments.size());
+            for (final Int2IntMap.Entry entry : value.enchantments.int2IntEntrySet()) {
+                Types.VAR_INT.writePrimitive(buffer, entry.getIntKey());
+                Types.VAR_INT.writePrimitive(buffer, entry.getIntValue());
+            }
+        }
+    };
 
     public Enchantments(final boolean showInTooltip) {
         this(new Int2IntOpenHashMap(), showInTooltip);
@@ -78,4 +106,9 @@ public record Enchantments(Int2IntMap enchantments, boolean showInTooltip) {
     public int getLevel(final int id) {
         return enchantments.getOrDefault(id, -1);
     }
+
+    @Override
+    public Enchantments copy() {
+        return new Enchantments(new Int2IntOpenHashMap(enchantments), showInTooltip);
+    }
 }

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

@@ -33,9 +33,14 @@ import org.checkerframework.checker.nullness.qual.Nullable;
 
 public record Equippable(int equipmentSlot, Holder<SoundEvent> soundEvent, @Nullable String model,
                          @Nullable String cameraOverlay, @Nullable HolderSet allowedEntities, boolean dispensable,
-                         boolean swappable, boolean damageOnHurt) {
+                         boolean swappable, boolean damageOnHurt, boolean equipOnInteract) {
 
-    public static final Type<Equippable> TYPE = new Type<>(Equippable.class) {
+    public Equippable(final int equipmentSlot, final Holder<SoundEvent> soundEvent, @Nullable final String model, @Nullable final String cameraOverlay,
+                      @Nullable final HolderSet allowedEntities, final boolean dispensable, final boolean swappable, final boolean damageOnHurt) {
+        this(equipmentSlot, soundEvent, model, cameraOverlay, allowedEntities, dispensable, swappable, damageOnHurt, true);
+    }
+
+    public static final Type<Equippable> TYPE1_21_2 = new Type<>(Equippable.class) {
         @Override
         public Equippable read(final ByteBuf buffer) {
             final int equipmentSlot = Types.VAR_INT.readPrimitive(buffer);
@@ -61,9 +66,37 @@ public record Equippable(int equipmentSlot, Holder<SoundEvent> soundEvent, @Null
             buffer.writeBoolean(value.damageOnHurt());
         }
     };
+    public static final Type<Equippable> TYPE1_21_5 = new Type<>(Equippable.class) {
+        @Override
+        public Equippable read(final ByteBuf buffer) {
+            final int equipmentSlot = Types.VAR_INT.readPrimitive(buffer);
+            final Holder<SoundEvent> soundEvent = Types.SOUND_EVENT.read(buffer);
+            final String model = Types.OPTIONAL_STRING.read(buffer);
+            final String cameraOverlay = Types.OPTIONAL_STRING.read(buffer);
+            final HolderSet allowedEntities = Types.OPTIONAL_HOLDER_SET.read(buffer);
+            final boolean dispensable = buffer.readBoolean();
+            final boolean swappable = buffer.readBoolean();
+            final boolean damageOnHurt = buffer.readBoolean();
+            final boolean equipOnInteract = buffer.readBoolean();
+            return new Equippable(equipmentSlot, soundEvent, model, cameraOverlay, allowedEntities, dispensable, swappable, damageOnHurt, equipOnInteract);
+        }
+
+        @Override
+        public void write(final ByteBuf buffer, final Equippable value) {
+            Types.VAR_INT.writePrimitive(buffer, value.equipmentSlot());
+            Types.SOUND_EVENT.write(buffer, value.soundEvent());
+            Types.OPTIONAL_STRING.write(buffer, value.model());
+            Types.OPTIONAL_STRING.write(buffer, value.cameraOverlay());
+            Types.OPTIONAL_HOLDER_SET.write(buffer, value.allowedEntities());
+            buffer.writeBoolean(value.dispensable());
+            buffer.writeBoolean(value.swappable());
+            buffer.writeBoolean(value.damageOnHurt());
+            buffer.writeBoolean(value.equipOnInteract());
+        }
+    };
 
     public Equippable rewrite(final Int2IntFunction soundIdRewriter) {
         final Holder<SoundEvent> soundEvent = this.soundEvent.updateId(soundIdRewriter);
-        return soundEvent == this.soundEvent ? this : new Equippable(equipmentSlot, soundEvent, model, cameraOverlay, allowedEntities, dispensable, swappable, damageOnHurt);
+        return soundEvent == this.soundEvent ? this : new Equippable(equipmentSlot, soundEvent, model, cameraOverlay, allowedEntities, dispensable, swappable, damageOnHurt, equipOnInteract);
     }
 }

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

@@ -25,9 +25,10 @@ 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 com.viaversion.viaversion.util.Copyable;
 import io.netty.buffer.ByteBuf;
 
-public record FireworkExplosion(int shape, int[] colors, int[] fadeColors, boolean hasTrail, boolean hasTwinkle) {
+public record FireworkExplosion(int shape, int[] colors, int[] fadeColors, boolean hasTrail, boolean hasTwinkle) implements Copyable {
     public static final Type<FireworkExplosion> TYPE = new Type<>(FireworkExplosion.class) {
         @Override
         public FireworkExplosion read(final ByteBuf buffer) {
@@ -50,4 +51,8 @@ public record FireworkExplosion(int shape, int[] colors, int[] fadeColors, boole
     };
     public static final Type<FireworkExplosion[]> ARRAY_TYPE = new ArrayType<>(TYPE);
 
+    @Override
+    public FireworkExplosion copy() {
+        return new FireworkExplosion(shape, copy(colors), copy(fadeColors), hasTrail, hasTwinkle);
+    }
 }

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

@@ -24,9 +24,10 @@ 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.util.Copyable;
 import io.netty.buffer.ByteBuf;
 
-public record Fireworks(int flightDuration, FireworkExplosion[] explosions) {
+public record Fireworks(int flightDuration, FireworkExplosion[] explosions) implements Copyable {
 
     public static final Type<Fireworks> TYPE = new Type<>(Fireworks.class) {
         @Override
@@ -43,4 +44,8 @@ public record Fireworks(int flightDuration, FireworkExplosion[] explosions) {
         }
     };
 
+    @Override
+    public Fireworks copy() {
+        return new Fireworks(flightDuration, copy(explosions));
+    }
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/FoodProperties1_20_5.java

@@ -27,11 +27,12 @@ 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.version.Types1_21;
+import com.viaversion.viaversion.util.Copyable;
 import io.netty.buffer.ByteBuf;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 public record FoodProperties1_20_5(int nutrition, float saturationModifier, boolean canAlwaysEat, float eatSeconds,
-                                   @Nullable Item usingConvertsTo, FoodEffect[] possibleEffects) {
+                                   @Nullable Item usingConvertsTo, FoodEffect[] possibleEffects) implements Copyable {
 
     public static final Type<FoodProperties1_20_5> TYPE1_20_5 = new Type<>(FoodProperties1_20_5.class) {
         @Override
@@ -76,6 +77,11 @@ public record FoodProperties1_20_5(int nutrition, float saturationModifier, bool
         }
     };
 
+    @Override
+    public FoodProperties1_20_5 copy() {
+        return new FoodProperties1_20_5(nutrition, saturationModifier, canAlwaysEat, eatSeconds, usingConvertsTo == null ? null : usingConvertsTo.copy(), copy(possibleEffects));
+    }
+
     public record FoodEffect(PotionEffect effect, float probability) {
 
         public static final Type<FoodEffect> TYPE = new Type<>(FoodEffect.class) {

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/Instrument1_21_2.java

@@ -26,11 +26,13 @@ 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.Types;
+import com.viaversion.viaversion.api.type.types.misc.EitherHolderType;
 import com.viaversion.viaversion.api.type.types.misc.HolderType;
+import com.viaversion.viaversion.util.Copyable;
 import io.netty.buffer.ByteBuf;
 import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 
-public record Instrument1_21_2(Holder<SoundEvent> soundEvent, float useDuration, float range, Tag description) {
+public record Instrument1_21_2(Holder<SoundEvent> soundEvent, float useDuration, float range, Tag description) implements Copyable {
 
     public static final HolderType<Instrument1_21_2> TYPE = new HolderType<>() {
         @Override
@@ -50,9 +52,15 @@ public record Instrument1_21_2(Holder<SoundEvent> soundEvent, float useDuration,
             Types.TAG.write(buffer, value.description());
         }
     };
+    public static final EitherHolderType<Instrument1_21_2> EITHER_HOLDER_TYPE = new EitherHolderType<>(TYPE);
 
     public Instrument1_21_2 rewrite(final Int2IntFunction soundIdRewriteFunction) {
         final Holder<SoundEvent> soundEvent = this.soundEvent.updateId(soundIdRewriteFunction);
         return soundEvent == this.soundEvent ? this : new Instrument1_21_2(soundEvent, useDuration, range, description);
     }
+
+    @Override
+    public Instrument1_21_2 copy() {
+        return new Instrument1_21_2(soundEvent, useDuration, range, description.copy());
+    }
 }

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

@@ -23,46 +23,59 @@
 package com.viaversion.viaversion.api.minecraft.item.data;
 
 import com.viaversion.nbt.tag.Tag;
+import com.viaversion.viaversion.api.minecraft.EitherHolder;
 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.EitherHolderType;
 import com.viaversion.viaversion.api.type.types.misc.HolderType;
-import com.viaversion.viaversion.util.Either;
 import io.netty.buffer.ByteBuf;
 import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 
-public record JukeboxPlayable(Either<Holder<JukeboxSong>, String> song, boolean showInTooltip) {
+public record JukeboxPlayable(EitherHolder<JukeboxSong> song, boolean showInTooltip) {
 
     public JukeboxPlayable(final Holder<JukeboxSong> song, final boolean showInTooltip) {
-        this(Either.left(song), showInTooltip);
+        this(EitherHolder.of(song), showInTooltip);
     }
 
     public JukeboxPlayable(final String resourceKey, final boolean showInTooltip) {
-        this(Either.right(resourceKey), showInTooltip);
+        this(EitherHolder.of(resourceKey), showInTooltip);
     }
 
-    public static final Type<JukeboxPlayable> TYPE = new Type<>(JukeboxPlayable.class) {
+    public static final Type<JukeboxPlayable> TYPE1_21 = 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 EitherHolder<JukeboxSong> position = EitherHolderType.read(buffer, JukeboxSong.TYPE);
             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);
+            EitherHolderType.write(buffer, value.song, JukeboxSong.TYPE);
             buffer.writeBoolean(value.showInTooltip);
         }
     };
+    public static final Type<JukeboxPlayable> TYPE1_21_5 = new Type<>(JukeboxPlayable.class) {
+        @Override
+        public JukeboxPlayable read(final ByteBuf buffer) {
+            final EitherHolder<JukeboxSong> position = EitherHolderType.read(buffer, JukeboxSong.TYPE);
+            return new JukeboxPlayable(position, true);
+        }
+
+        @Override
+        public void write(final ByteBuf buffer, final JukeboxPlayable value) {
+            EitherHolderType.write(buffer, value.song, JukeboxSong.TYPE);
+        }
+    };
 
     public JukeboxPlayable rewrite(final Int2IntFunction soundIdRewriteFunction) {
-        if (song.isRight()) {
+        if (this.song.hasKey()) {
             return this;
         }
 
-        final Holder<JukeboxSong> songHolder = this.song.left();
+        final Holder<JukeboxSong> songHolder = this.song.holder();
         if (songHolder.hasId()) {
             return this;
         }

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

@@ -24,10 +24,11 @@ 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.util.Copyable;
 import io.netty.buffer.ByteBuf;
 import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 
-public final class PotDecorations {
+public final class PotDecorations implements Copyable {
 
     public static final Type<PotDecorations> TYPE = new Type<>(PotDecorations.class) {
         @Override
@@ -82,4 +83,9 @@ public final class PotDecorations {
         }
         return new PotDecorations(newItems);
     }
+
+    @Override
+    public PotDecorations copy() {
+        return new PotDecorations(copy(itemIds));
+    }
 }

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

@@ -24,11 +24,12 @@ 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.util.Copyable;
 import io.netty.buffer.ByteBuf;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 public record PotionContents(@Nullable Integer potion, @Nullable Integer customColor, PotionEffect[] customEffects,
-                             @Nullable String customName) {
+                             @Nullable String customName) implements Copyable {
 
     public PotionContents(final @Nullable Integer potion, final @Nullable Integer customColor, final PotionEffect[] customEffects) {
         this(potion, customColor, customEffects, null);
@@ -85,4 +86,9 @@ public record PotionContents(@Nullable Integer potion, @Nullable Integer customC
             Types.OPTIONAL_STRING.write(buffer, value.customName);
         }
     };
+
+    @Override
+    public PotionContents copy() {
+        return new PotionContents(potion, customColor, copy(customEffects), customName);
+    }
 }

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

@@ -0,0 +1,56 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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.minecraft.EitherHolder;
+import com.viaversion.viaversion.api.minecraft.Holder;
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.types.misc.EitherHolderType;
+import io.netty.buffer.ByteBuf;
+import it.unimi.dsi.fastutil.ints.Int2IntFunction;
+
+public record ProvidesTrimMaterial(EitherHolder<ArmorTrimMaterial> material) {
+
+    public static final Type<ProvidesTrimMaterial> TYPE = new Type<>(ProvidesTrimMaterial.class) {
+
+        @Override
+        public ProvidesTrimMaterial read(final ByteBuf buffer) {
+            final EitherHolder<ArmorTrimMaterial> position = EitherHolderType.read(buffer, ArmorTrimMaterial.TYPE1_21_5);
+            return new ProvidesTrimMaterial(position);
+        }
+
+        @Override
+        public void write(final ByteBuf buffer, final ProvidesTrimMaterial value) {
+            EitherHolderType.write(buffer, value.material, ArmorTrimMaterial.TYPE1_21_5);
+        }
+    };
+
+    public ProvidesTrimMaterial rewrite(final Int2IntFunction itemIdRewriter) {
+        if (material.hasKey() || material.holder().hasId()) {
+            return this;
+        }
+
+        final ArmorTrimMaterial trimMaterial = material.holder().value();
+        return new ProvidesTrimMaterial(EitherHolder.of(Holder.of(trimMaterial.rewrite(itemIdRewriter))));
+    }
+}

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

@@ -27,15 +27,19 @@ 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) {
+public record ToolProperties(ToolRule[] rules, float defaultMiningSpeed, int damagePerBlock, boolean canDestroyBlocksInCreative) {
 
-    public static final Type<ToolProperties> TYPE = new Type<>(ToolProperties.class) {
+    public ToolProperties(final ToolRule[] rules, final float defaultMiningSpeed, final int damagePerBlock) {
+        this(rules, defaultMiningSpeed, damagePerBlock, false);
+    }
+
+    public static final Type<ToolProperties> TYPE1_20_5 = new Type<>(ToolProperties.class) {
         @Override
         public ToolProperties read(final ByteBuf buffer) {
             final ToolRule[] rules = ToolRule.ARRAY_TYPE.read(buffer);
             final float defaultMiningSpeed = buffer.readFloat();
             final int damagePerBlock = Types.VAR_INT.readPrimitive(buffer);
-            return new ToolProperties(rules, defaultMiningSpeed, damagePerBlock);
+            return new ToolProperties(rules, defaultMiningSpeed, damagePerBlock, true);
         }
 
         @Override
@@ -45,12 +49,30 @@ public record ToolProperties(ToolRule[] rules, float defaultMiningSpeed, int dam
             Types.VAR_INT.writePrimitive(buffer, value.damagePerBlock());
         }
     };
+    public static final Type<ToolProperties> TYPE1_21_5 = new Type<>(ToolProperties.class) {
+        @Override
+        public ToolProperties read(final ByteBuf buffer) {
+            final ToolRule[] rules = ToolRule.ARRAY_TYPE.read(buffer);
+            final float defaultMiningSpeed = buffer.readFloat();
+            final int damagePerBlock = Types.VAR_INT.readPrimitive(buffer);
+            final boolean canDestroyBlocksInCreative = buffer.readBoolean();
+            return new ToolProperties(rules, defaultMiningSpeed, damagePerBlock, canDestroyBlocksInCreative);
+        }
+
+        @Override
+        public void write(final ByteBuf buffer, final ToolProperties value) {
+            ToolRule.ARRAY_TYPE.write(buffer, value.rules());
+            buffer.writeFloat(value.defaultMiningSpeed());
+            Types.VAR_INT.writePrimitive(buffer, value.damagePerBlock());
+            buffer.writeBoolean(value.canDestroyBlocksInCreative());
+        }
+    };
 
     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);
+        return new ToolProperties(rules, defaultMiningSpeed, damagePerBlock, canDestroyBlocksInCreative);
     }
 }

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

@@ -0,0 +1,69 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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 io.netty.buffer.ByteBuf;
+import it.unimi.dsi.fastutil.ints.Int2IntFunction;
+import it.unimi.dsi.fastutil.ints.IntLinkedOpenHashSet;
+import it.unimi.dsi.fastutil.ints.IntSortedSet;
+
+public record TooltipDisplay(boolean hideTooltip,
+                             IntSortedSet hiddenComponents) { // Keeping the ids raw makes this less annoying to deal with...
+
+    public static final Type<TooltipDisplay> TYPE = new Type<>(TooltipDisplay.class) {
+
+        @Override
+        public TooltipDisplay read(final ByteBuf buffer) {
+            final boolean hideTooltip = buffer.readBoolean();
+            final IntSortedSet hiddenComponents = new IntLinkedOpenHashSet();
+            final int size = Types.VAR_INT.readPrimitive(buffer);
+            for (int i = 0; i < size; i++) {
+                hiddenComponents.add(Types.VAR_INT.readPrimitive(buffer));
+            }
+            return new TooltipDisplay(hideTooltip, hiddenComponents);
+        }
+
+        @Override
+        public void write(final ByteBuf buffer, final TooltipDisplay value) {
+            buffer.writeBoolean(value.hideTooltip());
+            Types.VAR_INT.writePrimitive(buffer, value.hiddenComponents().size());
+            for (int hiddenComponent : value.hiddenComponents()) {
+                Types.VAR_INT.writePrimitive(buffer, hiddenComponent);
+            }
+        }
+    };
+
+    public TooltipDisplay rewrite(final Int2IntFunction idRewriter) {
+        if (hiddenComponents.isEmpty()) {
+            return this;
+        }
+
+        final IntSortedSet newHiddenComponents = new IntLinkedOpenHashSet();
+        for (final int hiddenComponent : hiddenComponents) {
+            newHiddenComponents.add(idRewriter.applyAsInt(hiddenComponent));
+        }
+        return new TooltipDisplay(hideTooltip, newHiddenComponents);
+    }
+}

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

@@ -0,0 +1,45 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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 io.netty.buffer.ByteBuf;
+
+public record Weapon(int itemDamagePerAttack, float disableBlockingForSeconds) {
+
+    public static final Type<Weapon> TYPE = new Type<>(Weapon.class) {
+        @Override
+        public Weapon read(final ByteBuf buffer) {
+            final int damagePerAttack = Types.VAR_INT.readPrimitive(buffer);
+            final float disableBlockingForSeconds = buffer.readFloat();
+            return new Weapon(damagePerAttack, disableBlockingForSeconds);
+        }
+
+        @Override
+        public void write(final ByteBuf buffer, final Weapon value) {
+            Types.VAR_INT.writePrimitive(buffer, value.itemDamagePerAttack());
+            buffer.writeFloat(value.disableBlockingForSeconds());
+        }
+    };
+}

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

@@ -24,10 +24,11 @@ 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.util.Copyable;
 import io.netty.buffer.ByteBuf;
 
 public record WrittenBook(FilterableString title, String author, int generation, FilterableComponent[] pages,
-                          boolean resolved) {
+                          boolean resolved) implements Copyable {
 
     public static final Type<WrittenBook> TYPE = new Type<>(WrittenBook.class) {
         @Override
@@ -50,4 +51,8 @@ public record WrittenBook(FilterableString title, String author, int generation,
         }
     };
 
+    @Override
+    public WrittenBook copy() {
+        return new WrittenBook(title, author, generation, copy(pages), resolved);
+    }
 }

api/src/main/java/com/viaversion/viaversion/api/platform/ViaInjector.java

@@ -58,7 +58,7 @@ public interface ViaInjector {
      * For proxies, this returns the lowest supported protocol version.
      *
      * @return server protocol version
-     * @throws Exception if there is an error with getting this info, e.g. not binded
+     * @throws Exception if there is an error with getting this info, e.g. not bound
      * @see ViaPlatform#isProxy()
      */
     ProtocolVersion getServerProtocolVersion() throws Exception;
@@ -67,7 +67,7 @@ public interface ViaInjector {
      * Returns the supported server protocol versions.
      *
      * @return server protocol versions
-     * @throws Exception if there is an error with getting this info, e.g. not binded
+     * @throws Exception if there is an error with getting this info, e.g. not bound
      * @see ViaPlatform#isProxy()
      */
     default SortedSet<ProtocolVersion> getServerProtocolVersions() throws Exception {

api/src/main/java/com/viaversion/viaversion/api/platform/ViaPlatform.java

@@ -24,13 +24,11 @@ package com.viaversion.viaversion.api.platform;
 
 import com.google.gson.JsonObject;
 import com.viaversion.viaversion.api.ViaAPI;
-import com.viaversion.viaversion.api.command.ViaCommandSender;
 import com.viaversion.viaversion.api.configuration.ViaVersionConfig;
 import com.viaversion.viaversion.api.connection.UserConnection;
 import java.io.File;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.UUID;
 import java.util.logging.Logger;
 
 /**
@@ -120,52 +118,36 @@ public interface ViaPlatform<T> {
      */
     PlatformTask runRepeatingSync(Runnable runnable, long period);
 
-    /**
-     * Get the online players
-     *
-     * @return Array of ViaCommandSender
-     */
-    ViaCommandSender[] getOnlinePlayers();
-
     /**
      * Send a message to a player
      *
-     * @param uuid    The player's UUID
-     * @param message The message to send
+     * @param connection The UserConnection
+     * @param message    The message to send
      */
-    void sendMessage(UUID uuid, String message);
+    default void sendMessage(UserConnection connection, String message) {
+        throw new UnsupportedOperationException("ViaPlatform#sendMessage is not implemented on this platform.");
+    }
 
     /**
      * Kick a player for a reason
      *
-     * @param uuid    The player's UUID
-     * @param message The message to kick them with
-     * @return True if it was successful
-     */
-    boolean kickPlayer(UUID uuid, String message);
-
-    /**
-     * Disconnects an UserConnection for a reason
-     *
      * @param connection The UserConnection
      * @param message    The message to kick them with
      * @return True if it was successful
      */
-    default boolean disconnect(UserConnection connection, String message) {
-        if (connection.isClientSide()) return false;
-        UUID uuid = connection.getProtocolInfo().getUuid();
-        if (uuid == null) return false;
-        return kickPlayer(uuid, message);
+    default boolean kickPlayer(UserConnection connection, String message) {
+        throw new UnsupportedOperationException("ViaPlatform#kickPlayer is not implemented on this platform.");
     }
 
     /**
-     * Check if the plugin is enabled.
+     * Send a custom payload to from a player to the server.
      *
-     * @return True if it is enabled
+     * @param connection The UserConnection
+     * @param channel    The channel to send the payload on
+     * @param message    The data to send
      */
-    @Deprecated(forRemoval = true)
-    default boolean isPluginEnabled() {
-        return true;
+    default void sendCustomPayload(UserConnection connection, String channel, byte[] message) {
+        throw new UnsupportedOperationException("ViaPlatform#sendCustomPayload is not implemented on this platform.");
     }
 
     /**
@@ -190,16 +172,21 @@ public interface ViaPlatform<T> {
     File getDataFolder();
 
     /**
-     * Called when a reload happens
+     * Called when ViaVersion is initialized twice during the same process, this happens on platforms where ViaVersion
+     * is loaded as a plugin which can be reloaded.
      */
-    void onReload();
+    default void onReload() {
+    }
 
     /**
-     * Get the JSON data required for /viaversion dump
+     * Gets optional platform specific data for /viaversion dump. This can be a specific version or a list of installed
+     * plugins on the platform.
      *
      * @return The json data
      */
-    JsonObject getDump();
+    default JsonObject getDump() {
+        return new JsonObject();
+    }
 
     /**
      * Returns an immutable collection of classes to be checked as unsupported software with their software name.

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

@@ -213,7 +213,7 @@ public abstract class AbstractProtocol<CU extends ClientboundPacketType, CM exte
     }
 
     /**
-     * Register the packets for this protocol. To be overriden.
+     * Register the packets for this protocol. To be overridden.
      */
     protected void registerPackets() {
         callRegister(getEntityRewriter());

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

@@ -46,7 +46,7 @@ import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
  * Abstract protocol class handling packet transformation between two protocol versions.
- * Clientbound and serverbount packet types can be set to enforce correct usage of them.
+ * Clientbound and Serverbound packet types can be set to enforce correct usage of them.
  *
  * @param <CU> unmapped clientbound packet types
  * @param <CM> mapped clientbound packet types
@@ -305,7 +305,7 @@ public interface Protocol<CU extends ClientboundPacketType, CM extends Clientbou
      * Returns true if this Protocol's {@link #loadMappingData()} method should be called.
      * <p>
      * This does *not* necessarily mean that {@link #getMappingData()} is non-null, since this may be
-     * overriden, depending on special cases.
+     * overridden, depending on special cases.
      *
      * @return true if this Protocol's {@link #loadMappingData()} method should be called
      */

api/src/main/java/com/viaversion/viaversion/api/protocol/packet/mapping/PacketMappings.java

@@ -34,7 +34,7 @@ public interface PacketMappings {
     /**
      * Returns a packet mapping for the given packet.
      *
-     * @param state      protocol stae
+     * @param state      protocol state
      * @param unmappedId unmapped packet id
      * @return packet mapping if present
      */

api/src/main/java/com/viaversion/viaversion/api/protocol/packet/provider/PacketTypeMap.java

@@ -24,6 +24,7 @@ package com.viaversion.viaversion.api.protocol.packet.provider;
 
 import com.google.common.base.Preconditions;
 import com.viaversion.viaversion.api.protocol.packet.PacketType;
+import it.unimi.dsi.fastutil.ints.Int2ObjectArrayMap;
 import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
 import java.util.Collection;
 import java.util.HashMap;
@@ -65,11 +66,25 @@ public interface PacketTypeMap<P extends PacketType> {
         return of(byName, types);
     }
 
-    static <T extends PacketType> PacketTypeMap<T> of(final Map<String, T> packetsByName, final Int2ObjectMap<T> packetsById) {
-        return new PacketTypeMapMap<>(packetsByName, packetsById);
+    static <T extends PacketType, E extends T> PacketTypeMap<T> ofUnsequenced(final Class<E> enumClass) {
+        final T[] types = enumClass.getEnumConstants();
+        Preconditions.checkArgument(types != null, "%s is not an enum", enumClass);
+        final Map<String, T> byName = new HashMap<>(types.length);
+        for (final T type : types) {
+            byName.put(type.getName(), type);
+        }
+        final Int2ObjectMap<T> byId = new Int2ObjectArrayMap<>();
+        for (T type : types) {
+            byId.put(type.getId(), type);
+        }
+        return of(byName, byId);
     }
 
     static <T extends PacketType> PacketTypeMap<T> of(final Map<String, T> packetsByName, final T[] packets) {
         return new PacketTypeArrayMap<>(packetsByName, packets);
     }
+
+    static <T extends PacketType> PacketTypeMap<T> of(final Map<String, T> packetsByName, final Int2ObjectMap<T> packetsById) {
+        return new PacketTypeMapMap<>(packetsByName, packetsById);
+    }
 }

api/src/main/java/com/viaversion/viaversion/api/protocol/remapper/PacketHandler.java

@@ -38,7 +38,7 @@ public interface PacketHandler {
     /**
      * Returns a new packet handler that runs the provided handler after this one.
      *
-     * @param handler packet handler to run aftet this one
+     * @param handler packet handler to run after this one
      * @return a new packet handler that runs the provided handler after this one
      */
     default PacketHandler then(final PacketHandler handler) {

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

@@ -88,6 +88,7 @@ public class ProtocolVersion implements Comparable<ProtocolVersion> {
     public static final ProtocolVersion v1_21 = register(767, "1.21-1.21.1", new SubVersionRange("1.21", 0, 1));
     public static final ProtocolVersion v1_21_2 = register(768, "1.21.2-1.21.3", new SubVersionRange("1.21", 2, 3));
     public static final ProtocolVersion v1_21_4 = register(769, "1.21.4");
+    public static final ProtocolVersion v1_21_5 = register(770, "1.21.5");
     public static final ProtocolVersion unknown = new ProtocolVersion(VersionType.SPECIAL, -1, -1, "UNKNOWN", null);
 
     static {

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

@@ -32,4 +32,6 @@ public interface ComponentRewriter {
     void processTag(UserConnection connection, @Nullable Tag tag);
 
     void processText(UserConnection connection, @Nullable JsonElement element);
+
+    JsonElement processText(UserConnection connection, @Nullable String json);
 }

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

@@ -44,9 +44,10 @@ public interface EntityRewriter<T extends Protocol<?, ?, ?, ?>> extends Rewriter
      * From 1.14 and onwards, this is the same exact value as {@link #typeFromId(int)}.
      *
      * @param type entity type id
+     * @param data entity data
      * @return EntityType from id
      */
-    default EntityType objectTypeFromId(int type) {
+    default EntityType objectTypeFromId(int type, int data) {
         return typeFromId(type);
     }
 

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

@@ -38,13 +38,13 @@ public abstract class RewriterBase<T extends Protocol<?, ?, ?, ?>> implements Re
     }
 
     /**
-     * To be overriden. Called when registering the rewriter.
+     * To be overridden. Called when registering the rewriter.
      */
     protected void registerPackets() {
     }
 
     /**
-     * To be overriden. Called when registering the rewriter.
+     * To be overridden. Called when registering the rewriter.
      */
     protected void registerRewrites() {
     }

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

@@ -22,9 +22,6 @@
  */
 package com.viaversion.viaversion.api.type;
 
-import com.viaversion.viaversion.util.Either;
-import io.netty.buffer.ByteBuf;
-
 /**
  * Type for buffer reading and writing.
  *
@@ -61,7 +58,7 @@ public abstract class Type<T> implements ByteBufReader<T>, ByteBufWriter<T> {
      * @return type name
      */
     public String getTypeName() {
-        return typeName != null ? typeName : this.getClass().getSimpleName();
+        return typeName != null && !typeName.isEmpty() ? typeName : this.getClass().getSimpleName();
     }
 
     /**
@@ -78,22 +75,4 @@ 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.java

@@ -26,12 +26,13 @@ import com.google.gson.JsonElement;
 import com.viaversion.nbt.tag.CompoundTag;
 import com.viaversion.nbt.tag.Tag;
 import com.viaversion.viaversion.api.minecraft.BlockChangeRecord;
+import com.viaversion.viaversion.api.minecraft.BlockPosition;
+import com.viaversion.viaversion.api.minecraft.ChunkPosition;
 import com.viaversion.viaversion.api.minecraft.EulerAngle;
 import com.viaversion.viaversion.api.minecraft.GameProfile;
 import com.viaversion.viaversion.api.minecraft.GlobalBlockPosition;
 import com.viaversion.viaversion.api.minecraft.HolderSet;
 import com.viaversion.viaversion.api.minecraft.PlayerMessageSignature;
-import com.viaversion.viaversion.api.minecraft.BlockPosition;
 import com.viaversion.viaversion.api.minecraft.ProfileKey;
 import com.viaversion.viaversion.api.minecraft.Quaternion;
 import com.viaversion.viaversion.api.minecraft.RegistryEntry;
@@ -40,9 +41,10 @@ import com.viaversion.viaversion.api.minecraft.Vector;
 import com.viaversion.viaversion.api.minecraft.Vector3f;
 import com.viaversion.viaversion.api.minecraft.VillagerData;
 import com.viaversion.viaversion.api.minecraft.blockentity.BlockEntity;
+import com.viaversion.viaversion.api.minecraft.chunks.Heightmap;
+import com.viaversion.viaversion.api.minecraft.item.HashedItem;
 import com.viaversion.viaversion.api.minecraft.item.Item;
 import com.viaversion.viaversion.api.minecraft.item.data.Enchantments;
-import com.viaversion.viaversion.api.minecraft.ChunkPosition;
 import com.viaversion.viaversion.api.type.types.ArrayType;
 import com.viaversion.viaversion.api.type.types.BitSetType;
 import com.viaversion.viaversion.api.type.types.BooleanArrayType;
@@ -74,6 +76,8 @@ import com.viaversion.viaversion.api.type.types.block.BlockChangeRecordType;
 import com.viaversion.viaversion.api.type.types.block.BlockEntityType1_18;
 import com.viaversion.viaversion.api.type.types.block.BlockEntityType1_20_2;
 import com.viaversion.viaversion.api.type.types.block.VarLongBlockChangeRecordType;
+import com.viaversion.viaversion.api.type.types.chunk.HeightmapType;
+import com.viaversion.viaversion.api.type.types.item.HashedItemType1_21_5;
 import com.viaversion.viaversion.api.type.types.item.ItemShortArrayType1_13;
 import com.viaversion.viaversion.api.type.types.item.ItemShortArrayType1_13_2;
 import com.viaversion.viaversion.api.type.types.item.ItemShortArrayType1_8;
@@ -81,11 +85,11 @@ import com.viaversion.viaversion.api.type.types.item.ItemType1_13;
 import com.viaversion.viaversion.api.type.types.item.ItemType1_13_2;
 import com.viaversion.viaversion.api.type.types.item.ItemType1_20_2;
 import com.viaversion.viaversion.api.type.types.item.ItemType1_8;
+import com.viaversion.viaversion.api.type.types.math.BlockPositionType1_14;
+import com.viaversion.viaversion.api.type.types.math.BlockPositionType1_8;
 import com.viaversion.viaversion.api.type.types.math.ChunkPositionType;
 import com.viaversion.viaversion.api.type.types.math.EulerAngleType;
 import com.viaversion.viaversion.api.type.types.math.GlobalBlockPositionType;
-import com.viaversion.viaversion.api.type.types.math.BlockPositionType1_14;
-import com.viaversion.viaversion.api.type.types.math.BlockPositionType1_8;
 import com.viaversion.viaversion.api.type.types.math.QuaternionType;
 import com.viaversion.viaversion.api.type.types.math.Vector3fType;
 import com.viaversion.viaversion.api.type.types.math.VectorType;
@@ -131,6 +135,7 @@ public final class Types {
     public static final DoubleType DOUBLE = new DoubleType();
 
     public static final LongType LONG = new LongType();
+    public static final Type<Long> OPTIONAL_LONG = new LongType.OptionalLongType();
     public static final Type<long[]> LONG_ARRAY_PRIMITIVE = new LongArrayType();
 
     public static final BooleanType BOOLEAN = new BooleanType();
@@ -212,7 +217,12 @@ public final class Types {
     public static final Type<HolderSet> OPTIONAL_HOLDER_SET = new HolderSetType.OptionalHolderSetType();
 
     public static final HolderType<SoundEvent> SOUND_EVENT = new SoundEventType();
+    public static final HolderType<SoundEvent> OPTIONAL_SOUND_EVENT = new SoundEventType.OptionalSoundEventType();
 
+    public static final Type<Heightmap> HEIGHTMAP = new HeightmapType();
+    public static final Type<Heightmap[]> HEIGHTMAP_ARRAY = new ArrayType<>(HEIGHTMAP);
+
+    // No longer used past 1.20.2
     public static final Type<Item> ITEM1_8 = new ItemType1_8();
     public static final Type<Item> ITEM1_13 = new ItemType1_13();
     public static final Type<Item> ITEM1_13_2 = new ItemType1_13_2();
@@ -223,4 +233,6 @@ public final class Types {
     public static final Type<Item[]> ITEM1_13_ARRAY = new ArrayType<>(ITEM1_13);
     public static final Type<Item[]> ITEM1_13_2_ARRAY = new ArrayType<>(ITEM1_13_2);
     public static final Type<Item[]> ITEM1_20_2_ARRAY = new ArrayType<>(ITEM1_20_2);
+
+    public static final Type<HashedItem> HASHED_ITEM = new HashedItemType1_21_5();
 }

api/src/main/java/com/viaversion/viaversion/api/type/types/EitherType.java

@@ -0,0 +1,67 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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;
+
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.util.Either;
+import io.netty.buffer.ByteBuf;
+
+// Yuck - only use when necessary
+public final class EitherType<T, V> extends Type<Either<T, V>> {
+    private final Type<T> leftType;
+    private final Type<V> rightType;
+
+    public EitherType(final Type<T> leftType, final Type<V> rightType) {
+        super(Either.class);
+        this.leftType = leftType;
+        this.rightType = rightType;
+    }
+
+    @Override
+    public Either<T, V> read(final ByteBuf buffer) {
+        return read(buffer, this.leftType, this.rightType);
+    }
+
+    @Override
+    public void write(final ByteBuf buffer, final Either<T, V> value) {
+        write(buffer, value, this.leftType, this.rightType);
+    }
+
+    public static <X, Y> Either<X, Y> read(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 write(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/LongArrayType.java

@@ -22,30 +22,51 @@
  */
 package com.viaversion.viaversion.api.type.types;
 
+import com.google.common.base.Preconditions;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
 import io.netty.buffer.ByteBuf;
 
 public class LongArrayType extends Type<long[]> {
 
-    public LongArrayType() {
+    private final int length;
+
+    public LongArrayType(final int length) {
         super(long[].class);
+        this.length = length;
+    }
+
+    public LongArrayType() {
+        this(-1);
     }
 
     @Override
-    public long[] read(ByteBuf buffer) {
-        int length = Types.VAR_INT.readPrimitive(buffer);
-        long[] array = new long[length];
-        for (int i = 0; i < array.length; i++) {
-            array[i] = buffer.readLong();
+    public long[] read(final ByteBuf buffer) {
+        final int length = this.length == -1 ? Types.VAR_INT.readPrimitive(buffer) : this.length;
+        Preconditions.checkArgument(buffer.isReadable(length), "Length is fewer than readable bytes");
+        return readFixedLength(buffer, length);
+    }
+
+    public static long[] readFixedLength(final ByteBuf buffer, final int expectedLength) {
+        final long[] value = new long[expectedLength];
+        for (int i = 0; i < expectedLength; i++) {
+            value[i] = buffer.readLong();
         }
-        return array;
+        return value;
     }
 
     @Override
-    public void write(ByteBuf buffer, long[] object) {
-        Types.VAR_INT.writePrimitive(buffer, object.length);
-        for (long l : object) {
+    public void write(final ByteBuf buffer, final long[] object) {
+        if (this.length != -1) {
+            Preconditions.checkArgument(length == object.length, "Length does not match expected length");
+        } else {
+            Types.VAR_INT.writePrimitive(buffer, object.length);
+        }
+        writeFixedLength(buffer, object);
+    }
+
+    public static void writeFixedLength(final ByteBuf buffer, final long[] object) {
+        for (final long l : object) {
             buffer.writeLong(l);
         }
     }

api/src/main/java/com/viaversion/viaversion/api/type/types/LongType.java

@@ -22,8 +22,10 @@
  */
 package com.viaversion.viaversion.api.type.types;
 
+import com.viaversion.viaversion.api.type.OptionalType;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.TypeConverter;
+import com.viaversion.viaversion.api.type.Types;
 import io.netty.buffer.ByteBuf;
 
 public class LongType extends Type<Long> implements TypeConverter<Long> {
@@ -67,4 +69,11 @@ public class LongType extends Type<Long> implements TypeConverter<Long> {
     public void writePrimitive(ByteBuf buffer, long object) {
         buffer.writeLong(object);
     }
+
+    public static final class OptionalLongType extends OptionalType<Long> {
+
+        public OptionalLongType() {
+            super(Types.LONG);
+        }
+    }
 }

api/src/main/java/com/viaversion/viaversion/api/type/types/chunk/ChunkSectionType1_18.java

@@ -25,14 +25,15 @@ package com.viaversion.viaversion.api.type.types.chunk;
 import com.viaversion.viaversion.api.minecraft.chunks.Chunk;
 import com.viaversion.viaversion.api.minecraft.chunks.ChunkSection;
 import com.viaversion.viaversion.api.minecraft.chunks.ChunkSectionImpl;
+import com.viaversion.viaversion.api.minecraft.chunks.DataPalette;
 import com.viaversion.viaversion.api.minecraft.chunks.PaletteType;
 import com.viaversion.viaversion.api.type.Type;
 import io.netty.buffer.ByteBuf;
 
-public final class ChunkSectionType1_18 extends Type<ChunkSection> {
+public class ChunkSectionType1_18 extends Type<ChunkSection> {
 
-    private final PaletteType1_18 blockPaletteType;
-    private final PaletteType1_18 biomePaletteType;
+    private final PaletteTypeBase blockPaletteType;
+    private final PaletteTypeBase biomePaletteType;
 
     public ChunkSectionType1_18(final int globalPaletteBlockBits, final int globalPaletteBiomeBits) {
         super(ChunkSection.class);
@@ -40,6 +41,12 @@ public final class ChunkSectionType1_18 extends Type<ChunkSection> {
         this.biomePaletteType = new PaletteType1_18(PaletteType.BIOMES, globalPaletteBiomeBits);
     }
 
+    protected ChunkSectionType1_18(final PaletteTypeBase blockPaletteType, PaletteTypeBase biomePaletteType) {
+        super(ChunkSection.class);
+        this.blockPaletteType = blockPaletteType;
+        this.biomePaletteType = biomePaletteType;
+    }
+
     @Override
     public ChunkSection read(final ByteBuf buffer) {
         final ChunkSection chunkSection = new ChunkSectionImpl();

api/src/main/java/com/viaversion/viaversion/api/type/types/chunk/ChunkSectionType1_21_5.java

@@ -0,0 +1,35 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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.chunk;
+
+import com.viaversion.viaversion.api.minecraft.chunks.PaletteType;
+
+public class ChunkSectionType1_21_5 extends ChunkSectionType1_18 {
+
+    public ChunkSectionType1_21_5(final int globalPaletteBlockBits, final int globalPaletteBiomeBits) {
+        super(
+            new PaletteType1_21_5(PaletteType.BLOCKS, globalPaletteBlockBits),
+            new PaletteType1_21_5(PaletteType.BIOMES, globalPaletteBiomeBits)
+        );
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/type/types/chunk/ChunkType1_21_5.java

@@ -0,0 +1,88 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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.chunk;
+
+import com.google.common.base.Preconditions;
+import com.viaversion.viaversion.api.minecraft.blockentity.BlockEntity;
+import com.viaversion.viaversion.api.minecraft.chunks.Chunk;
+import com.viaversion.viaversion.api.minecraft.chunks.Chunk1_21_5;
+import com.viaversion.viaversion.api.minecraft.chunks.ChunkSection;
+import com.viaversion.viaversion.api.minecraft.chunks.Heightmap;
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.Types;
+import io.netty.buffer.ByteBuf;
+import java.util.ArrayList;
+import java.util.List;
+
+public final class ChunkType1_21_5 extends Type<Chunk> {
+    private final ChunkSectionType1_18 sectionType;
+    private final int ySectionCount;
+
+    public ChunkType1_21_5(final int ySectionCount, final int globalPaletteBlockBits, final int globalPaletteBiomeBits) {
+        super(Chunk.class);
+        Preconditions.checkArgument(ySectionCount > 0);
+        this.sectionType = new ChunkSectionType1_21_5(globalPaletteBlockBits, globalPaletteBiomeBits);
+        this.ySectionCount = ySectionCount;
+    }
+
+    @Override
+    public Chunk read(final ByteBuf buffer) {
+        final int chunkX = buffer.readInt();
+        final int chunkZ = buffer.readInt();
+
+        final Heightmap[] heightmaps = Types.HEIGHTMAP_ARRAY.read(buffer);
+
+        // Read sections
+        final ByteBuf sectionsBuf = buffer.readSlice(Types.VAR_INT.readPrimitive(buffer));
+        final ChunkSection[] sections = new ChunkSection[ySectionCount];
+        for (int i = 0; i < ySectionCount; i++) {
+            sections[i] = sectionType.read(sectionsBuf);
+        }
+
+        final int blockEntitiesLength = Types.VAR_INT.readPrimitive(buffer);
+        final List<BlockEntity> blockEntities = new ArrayList<>(blockEntitiesLength);
+        for (int i = 0; i < blockEntitiesLength; i++) {
+            blockEntities.add(Types.BLOCK_ENTITY1_20_2.read(buffer));
+        }
+
+        return new Chunk1_21_5(chunkX, chunkZ, sections, heightmaps, blockEntities);
+    }
+
+    @Override
+    public void write(final ByteBuf buffer, final Chunk chunk) {
+        buffer.writeInt(chunk.getX());
+        buffer.writeInt(chunk.getZ());
+
+        Types.HEIGHTMAP_ARRAY.write(buffer, chunk.heightmaps());
+
+        Types.VAR_INT.writePrimitive(buffer, sectionType.serializedSize(chunk));
+        for (final ChunkSection section : chunk.getSections()) {
+            sectionType.write(buffer, section);
+        }
+
+        Types.VAR_INT.writePrimitive(buffer, chunk.blockEntities().size());
+        for (final BlockEntity blockEntity : chunk.blockEntities()) {
+            Types.BLOCK_ENTITY1_20_2.write(buffer, blockEntity);
+        }
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/type/types/chunk/HeightmapType.java

@@ -0,0 +1,48 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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.chunk;
+
+import com.viaversion.viaversion.api.minecraft.chunks.Heightmap;
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.Types;
+import io.netty.buffer.ByteBuf;
+
+public final class HeightmapType extends Type<Heightmap> {
+
+    public HeightmapType() {
+        super(Heightmap.class);
+    }
+
+    @Override
+    public Heightmap read(final ByteBuf buffer) {
+        final int type = Types.VAR_INT.readPrimitive(buffer);
+        final long[] data = Types.LONG_ARRAY_PRIMITIVE.read(buffer);
+        return new Heightmap(type, data);
+    }
+
+    @Override
+    public void write(final ByteBuf buffer, final Heightmap value) {
+        Types.VAR_INT.writePrimitive(buffer, value.type());
+        Types.LONG_ARRAY_PRIMITIVE.write(buffer, value.data());
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/type/types/chunk/PaletteType1_18.java

@@ -25,19 +25,17 @@ package com.viaversion.viaversion.api.type.types.chunk;
 import com.viaversion.viaversion.api.minecraft.chunks.DataPalette;
 import com.viaversion.viaversion.api.minecraft.chunks.DataPaletteImpl;
 import com.viaversion.viaversion.api.minecraft.chunks.PaletteType;
-import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
 import com.viaversion.viaversion.api.type.types.VarIntType;
 import com.viaversion.viaversion.util.CompactArrayUtil;
 import com.viaversion.viaversion.util.MathUtil;
 import io.netty.buffer.ByteBuf;
 
-public final class PaletteType1_18 extends Type<DataPalette> {
-    private final int globalPaletteBits;
-    private final PaletteType type;
+public class PaletteType1_18 extends PaletteTypeBase {
+    protected final int globalPaletteBits;
+    protected final PaletteType type;
 
     public PaletteType1_18(final PaletteType type, final int globalPaletteBits) {
-        super(DataPalette.class);
         this.globalPaletteBits = globalPaletteBits;
         this.type = type;
     }
@@ -50,7 +48,7 @@ public final class PaletteType1_18 extends Type<DataPalette> {
             // Single value storage
             palette = new DataPaletteImpl(type.size(), 1);
             palette.addId(Types.VAR_INT.readPrimitive(buffer));
-            Types.LONG_ARRAY_PRIMITIVE.read(buffer); // Just eat it if not empty - thanks, Hypixel
+            readValues(buffer, 0, palette); // Just eat it if not empty - thanks, Hypixel
             return palette;
         }
 
@@ -72,6 +70,11 @@ public final class PaletteType1_18 extends Type<DataPalette> {
         }
 
         // Read values
+        readValues(buffer, bitsPerValue, palette);
+        return palette;
+    }
+
+    protected void readValues(final ByteBuf buffer, final int bitsPerValue, final DataPaletteImpl palette) {
         final long[] values = Types.LONG_ARRAY_PRIMITIVE.read(buffer);
         if (values.length > 0) {
             final int valuesPerLong = (char) (64 / bitsPerValue);
@@ -81,7 +84,6 @@ public final class PaletteType1_18 extends Type<DataPalette> {
                     bitsPerValue == globalPaletteBits ? palette::setIdAt : palette::setPaletteIndexAt);
             }
         }
-        return palette;
     }
 
     @Override
@@ -91,7 +93,7 @@ public final class PaletteType1_18 extends Type<DataPalette> {
             // Single value palette
             buffer.writeByte(0); // 0 bit storage
             Types.VAR_INT.writePrimitive(buffer, palette.idByIndex(0));
-            Types.VAR_INT.writePrimitive(buffer, 0); // Empty values length
+            writeValues(buffer, palette, 0);
             return;
         }
 
@@ -106,7 +108,22 @@ public final class PaletteType1_18 extends Type<DataPalette> {
             }
         }
 
-        Types.LONG_ARRAY_PRIMITIVE.write(buffer, CompactArrayUtil.createCompactArrayWithPadding(bitsPerValue, type.size(), bitsPerValue == globalPaletteBits ? palette::idAt : palette::paletteIndexAt));
+        writeValues(buffer, palette, bitsPerValue);
+    }
+
+    protected void writeValues(final ByteBuf buffer, final DataPalette palette, final int bitsPerValue) {
+        if (bitsPerValue == 0) {
+            // Single value storage with the first palette entry
+            Types.VAR_INT.writePrimitive(buffer, 0);
+            return;
+        }
+
+        final long[] values = CompactArrayUtil.createCompactArrayWithPadding(
+            bitsPerValue,
+            type.size(),
+            bitsPerValue == globalPaletteBits ? palette::idAt : palette::paletteIndexAt
+        );
+        Types.LONG_ARRAY_PRIMITIVE.write(buffer, values);
     }
 
     private int bitsPerValue(final int size) {
@@ -119,15 +136,17 @@ public final class PaletteType1_18 extends Type<DataPalette> {
         return bitsPerValue;
     }
 
+    @Override
     public int serializedSize(final DataPalette palette) {
         // This is a bit of extra work, but worth it to avoid otherwise having to allocate and write to an extra buffer.
         // On top of saving memory, it provides small but measurable speedup compared to writing to a separate buffer and then back
         final int size = palette.size();
         final int bitsPerValue = bitsPerValue(size);
+        final int serializedValuesSize;
         int serializedTypesSize = 0;
-        int serializedValuesSize = 1; // At least one byte for 0 length
         if (size == 1) {
             serializedTypesSize = VarIntType.varIntLength(palette.idByIndex(0));
+            serializedValuesSize = serializedValuesSize(0);
         } else {
             if (bitsPerValue != globalPaletteBits) {
                 serializedTypesSize = VarIntType.varIntLength(size);
@@ -138,9 +157,13 @@ public final class PaletteType1_18 extends Type<DataPalette> {
 
             final int valuesPerLong = 64 / bitsPerValue;
             final int values = (type.size() + valuesPerLong - 1) / valuesPerLong;
-            serializedValuesSize = VarIntType.varIntLength(values) + (Long.BYTES * values);
+            serializedValuesSize = serializedValuesSize(values);
         }
 
         return Byte.BYTES + serializedTypesSize + serializedValuesSize;
     }
+
+    protected int serializedValuesSize(final int values) {
+        return VarIntType.varIntLength(values) + (Long.BYTES * values);
+    }
 }

api/src/main/java/com/viaversion/viaversion/api/type/types/chunk/PaletteType1_21_5.java

@@ -0,0 +1,76 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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.chunk;
+
+import com.viaversion.viaversion.api.minecraft.chunks.DataPalette;
+import com.viaversion.viaversion.api.minecraft.chunks.DataPaletteImpl;
+import com.viaversion.viaversion.api.minecraft.chunks.PaletteType;
+import com.viaversion.viaversion.api.type.types.LongArrayType;
+import com.viaversion.viaversion.util.CompactArrayUtil;
+import io.netty.buffer.ByteBuf;
+
+// Values are written without the explicit length, as the length is always known
+public final class PaletteType1_21_5 extends PaletteType1_18 {
+
+    public PaletteType1_21_5(final PaletteType type, final int globalPaletteBits) {
+        super(type, globalPaletteBits);
+    }
+
+    @Override
+    protected void readValues(final ByteBuf buffer, final int bitsPerValue, final DataPaletteImpl palette) {
+        if (bitsPerValue == 0) {
+            return;
+        }
+
+        final int valuesPerLong = (char) (64 / bitsPerValue);
+        final int expectedLength = (type.size() + valuesPerLong - 1) / valuesPerLong;
+        final long[] values = LongArrayType.readFixedLength(buffer, expectedLength);
+        if (values.length != 0) {
+            CompactArrayUtil.iterateCompactArrayWithPadding(
+                bitsPerValue,
+                type.size(),
+                values,
+                bitsPerValue == globalPaletteBits ? palette::setIdAt : palette::setPaletteIndexAt
+            );
+        }
+    }
+
+    @Override
+    protected void writeValues(final ByteBuf buffer, final DataPalette palette, final int bitsPerValue) {
+        if (bitsPerValue == 0) {
+            return;
+        }
+
+        final long[] values = CompactArrayUtil.createCompactArrayWithPadding(
+            bitsPerValue,
+            type.size(),
+            bitsPerValue == globalPaletteBits ? palette::idAt : palette::paletteIndexAt
+        );
+        LongArrayType.writeFixedLength(buffer, values);
+    }
+
+    @Override
+    protected int serializedValuesSize(final int values) {
+        return Long.BYTES * values;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/type/types/chunk/PaletteTypeBase.java

@@ -0,0 +1,42 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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.chunk;
+
+import com.viaversion.viaversion.api.minecraft.chunks.DataPalette;
+import com.viaversion.viaversion.api.type.Type;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+public abstract class PaletteTypeBase extends Type<DataPalette> {
+
+    protected PaletteTypeBase() {
+        super(DataPalette.class);
+    }
+
+    /**
+     * Calculates the size of the serialized data in bytes.
+     *
+     * @param palette data palette
+     * @return the size of the serialized data in bytes
+     */
+    public abstract int serializedSize(@Nullable DataPalette palette);
+}

api/src/main/java/com/viaversion/viaversion/api/type/types/item/HashedItemType1_21_5.java

@@ -0,0 +1,90 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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.item;
+
+import com.viaversion.viaversion.api.minecraft.item.HashedItem;
+import com.viaversion.viaversion.api.minecraft.item.HashedStructuredItem;
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.util.Limit;
+import io.netty.buffer.ByteBuf;
+import it.unimi.dsi.fastutil.ints.Int2IntMap;
+import it.unimi.dsi.fastutil.ints.Int2IntOpenHashMap;
+import it.unimi.dsi.fastutil.ints.IntOpenHashSet;
+import it.unimi.dsi.fastutil.ints.IntSet;
+
+public class HashedItemType1_21_5 extends Type<HashedItem> {
+
+    public HashedItemType1_21_5() {
+        super(HashedItem.class);
+    }
+
+    @Override
+    public HashedItem read(final ByteBuf buffer) {
+        if (!buffer.readBoolean()) {
+            return HashedStructuredItem.empty();
+        }
+
+        final int id = Types.VAR_INT.readPrimitive(buffer);
+        final int amount = Types.VAR_INT.readPrimitive(buffer);
+
+        final int addedComponentsSize = Limit.max(Types.VAR_INT.readPrimitive(buffer), 256);
+        final Int2IntMap dataHashes = new Int2IntOpenHashMap(addedComponentsSize);
+        for (int i = 0; i < addedComponentsSize; i++) {
+            final int dataType = Types.VAR_INT.readPrimitive(buffer);
+            final int hash = Types.INT.readPrimitive(buffer);
+            dataHashes.put(dataType, hash);
+        }
+
+        final int removedComponentsSize = Limit.max(Types.VAR_INT.readPrimitive(buffer), 256);
+        final IntSet removedData = new IntOpenHashSet(removedComponentsSize);
+        for (int i = 0; i < removedComponentsSize; i++) {
+            final int dataType = Types.VAR_INT.readPrimitive(buffer);
+            removedData.add(dataType);
+        }
+        return new HashedStructuredItem(id, amount, dataHashes, removedData);
+    }
+
+    @Override
+    public void write(final ByteBuf buffer, final HashedItem value) {
+        if (value.isEmpty()) {
+            buffer.writeBoolean(false);
+            return;
+        }
+
+        buffer.writeBoolean(true);
+        Types.VAR_INT.writePrimitive(buffer, value.identifier());
+        Types.VAR_INT.writePrimitive(buffer, value.amount());
+
+        Types.VAR_INT.writePrimitive(buffer, value.dataHashesById().size());
+        for (final Int2IntMap.Entry entry : value.dataHashesById().int2IntEntrySet()) {
+            Types.VAR_INT.writePrimitive(buffer, entry.getIntKey());
+            Types.INT.writePrimitive(buffer, entry.getIntValue());
+        }
+
+        Types.VAR_INT.writePrimitive(buffer, value.removedDataIds().size());
+        for (final int removedDataId : value.removedDataIds()) {
+            Types.VAR_INT.writePrimitive(buffer, removedDataId);
+        }
+    }
+}

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

@@ -37,9 +37,9 @@ import java.util.Map;
 
 public class ItemType1_20_5 extends Type<Item> {
 
-    private final StructuredDataType dataType;
+    private final StructuredDataTypeBase dataType;
 
-    public ItemType1_20_5(final StructuredDataType dataType) {
+    public ItemType1_20_5(final StructuredDataTypeBase dataType) {
         super(Item.class);
         this.dataType = dataType;
     }
@@ -60,7 +60,7 @@ public class ItemType1_20_5 extends Type<Item> {
         final int valuesSize = Types.VAR_INT.readPrimitive(buffer);
         final int markersSize = Types.VAR_INT.readPrimitive(buffer);
         if (valuesSize == 0 && markersSize == 0) {
-            return new Reference2ObjectOpenHashMap<>();
+            return new Reference2ObjectOpenHashMap<>(0);
         }
 
         final Map<StructuredDataKey<?>, StructuredData<?>> map = new Reference2ObjectOpenHashMap<>(Math.min(valuesSize + markersSize, 128));

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

@@ -0,0 +1,76 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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.item;
+
+import com.viaversion.viaversion.api.minecraft.data.StructuredData;
+import com.viaversion.viaversion.api.minecraft.data.StructuredDataKey;
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.Types;
+import io.netty.buffer.ByteBuf;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+/**
+ * Wraps a data component codec, where data components are prefixed with their byte size (used in creative mode packets).
+ */
+public class LengthPrefixedStructuredDataType extends Type<StructuredData<?>> implements StructuredDataTypeBase {
+
+    private final StructuredDataType wrapped;
+
+    public LengthPrefixedStructuredDataType(final StructuredDataType dataType) {
+        super(StructuredData.class);
+        this.wrapped = dataType;
+    }
+
+    @Override
+    public void write(final ByteBuf buffer, final StructuredData<?> value) {
+        Types.VAR_INT.writePrimitive(buffer, value.id());
+
+        // Same deal as with chunk data, except pre-calculating the size would be madness
+        final ByteBuf tempBuf = buffer.alloc().buffer();
+        try {
+            value.write(tempBuf);
+            Types.VAR_INT.writePrimitive(buffer, tempBuf.readableBytes());
+            buffer.writeBytes(tempBuf);
+        } finally {
+            tempBuf.release();
+        }
+    }
+
+    @Override
+    public StructuredData<?> read(final ByteBuf buffer) {
+        final int id = Types.VAR_INT.readPrimitive(buffer);
+        final StructuredDataKey<?> key = key(id);
+        if (key == null) {
+            throw new IllegalArgumentException("No data component serializer found for id " + id);
+        }
+
+        final int size = Types.VAR_INT.readPrimitive(buffer);
+        final ByteBuf slicedBuf = buffer.readSlice(size);
+        return wrapped.readData(slicedBuf, key, id);
+    }
+
+    @Override
+    public @Nullable StructuredDataKey<?> key(final int id) {
+        return wrapped.key(id);
+    }
+}

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

@@ -32,7 +32,7 @@ import com.viaversion.viaversion.api.type.Types;
 import io.netty.buffer.ByteBuf;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
-public class StructuredDataType extends Type<StructuredData<?>> {
+public class StructuredDataType extends Type<StructuredData<?>> implements StructuredDataTypeBase {
 
     private StructuredDataKey<?>[] types;
 
@@ -57,11 +57,12 @@ public class StructuredDataType extends Type<StructuredData<?>> {
         return readData(buffer, key, id);
     }
 
+    @Override
     public @Nullable StructuredDataKey<?> key(final int id) {
         return id >= 0 && id < types.length ? types[id] : null;
     }
 
-    private <T> StructuredData<T> readData(final ByteBuf buffer, final StructuredDataKey<T> key, final int id) {
+    <T> StructuredData<T> readData(final ByteBuf buffer, final StructuredDataKey<T> key, final int id) {
         return StructuredData.of(key, key.type().read(buffer), id);
     }
 

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

@@ -0,0 +1,37 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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.item;
+
+import com.viaversion.viaversion.api.minecraft.data.StructuredData;
+import com.viaversion.viaversion.api.minecraft.data.StructuredDataKey;
+import io.netty.buffer.ByteBuf;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+public interface StructuredDataTypeBase {
+
+    StructuredData<?> read(ByteBuf buffer);
+
+    void write(ByteBuf buffer, StructuredData<?> value);
+
+    @Nullable StructuredDataKey<?> key(int id);
+}

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

@@ -0,0 +1,64 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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.misc;
+
+import com.viaversion.viaversion.api.minecraft.EitherHolder;
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.Types;
+import io.netty.buffer.ByteBuf;
+
+public final class EitherHolderType<T> extends Type<EitherHolder<T>> {
+    private final HolderType<T> holderType;
+
+    public EitherHolderType(final HolderType<T> holderType) {
+        super(EitherHolder.class);
+        this.holderType = holderType;
+    }
+
+    @Override
+    public EitherHolder<T> read(final ByteBuf buffer) {
+        return read(buffer, this.holderType);
+    }
+
+    @Override
+    public void write(final ByteBuf buffer, final EitherHolder<T> object) {
+        write(buffer, object, this.holderType);
+    }
+
+    public static <T> EitherHolder<T> read(final ByteBuf buffer, final HolderType<T> holderType) {
+        if (buffer.readBoolean()) {
+            return EitherHolder.of(holderType.read(buffer));
+        }
+        return EitherHolder.of(Types.STRING.read(buffer));
+    }
+
+    public static <T> void write(final ByteBuf buffer, final EitherHolder<T> object, final HolderType<T> holderType) {
+        if (object.hasHolder()) {
+            buffer.writeBoolean(true);
+            holderType.write(buffer, object.holder());
+        } else {
+            buffer.writeBoolean(false);
+            Types.STRING.write(buffer, object.key());
+        }
+    }
+}

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

@@ -26,6 +26,7 @@ import com.viaversion.viaversion.api.minecraft.Holder;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
 import io.netty.buffer.ByteBuf;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 public abstract class HolderType<T> extends Type<Holder<T>> {
 
@@ -55,4 +56,37 @@ public abstract class HolderType<T> extends Type<Holder<T>> {
     public abstract T readDirect(final ByteBuf buffer);
 
     public abstract void writeDirect(final ByteBuf buffer, final T object);
+
+    public abstract static class OptionalHolderType<T> extends HolderType<T> {
+        private final HolderType<T> type;
+
+        protected OptionalHolderType(final HolderType<T> type) {
+            this.type = type;
+        }
+
+        @Override
+        public Holder<T> read(final ByteBuf buffer) {
+            return buffer.readBoolean() ? super.read(buffer) : null;
+        }
+
+        @Override
+        public void write(final ByteBuf buffer, final Holder<T> object) {
+            if (object != null) {
+                buffer.writeBoolean(true);
+                super.write(buffer, object);
+            } else {
+                buffer.writeBoolean(false);
+            }
+        }
+
+        @Override
+        public @Nullable T readDirect(ByteBuf buffer) {
+            return this.type.readDirect(buffer);
+        }
+
+        @Override
+        public void writeDirect(final ByteBuf buffer, @Nullable final T value) {
+            this.type.writeDirect(buffer, value);
+        }
+    }
 }

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

@@ -40,4 +40,11 @@ public final class SoundEventType extends HolderType<SoundEvent> {
         Types.STRING.write(buffer, value.identifier());
         Types.OPTIONAL_FLOAT.write(buffer, value.fixedRange());
     }
+
+    public static final class OptionalSoundEventType extends OptionalHolderType<SoundEvent> {
+
+        public OptionalSoundEventType() {
+            super(Types.SOUND_EVENT);
+        }
+    }
 }

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

@@ -25,6 +25,7 @@ package com.viaversion.viaversion.api.type.types.misc;
 import com.viaversion.nbt.io.TagRegistry;
 import com.viaversion.nbt.limiter.TagLimiter;
 import com.viaversion.nbt.tag.Tag;
+import com.viaversion.viaversion.api.Via;
 import com.viaversion.viaversion.api.type.OptionalType;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
@@ -49,7 +50,11 @@ public class TagType extends Type<Tag> {
         try {
             return TagRegistry.read(id, new ByteBufInputStream(buffer), tagLimiter, 0);
         } catch (final IOException e) {
-            throw new RuntimeException(e);
+            if (Via.getManager().isDebug()) {
+                throw new RuntimeException(e);
+            } else {
+                throw new RuntimeException("Error reading tag :" + e.getMessage());
+            }
         }
     }
 

api/src/main/java/com/viaversion/viaversion/api/type/types/version/Types1_21_5.java

@@ -0,0 +1,58 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 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_5;
+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.LengthPrefixedStructuredDataType;
+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_5 {
+
+    public static final StructuredDataType STRUCTURED_DATA = new StructuredDataType();
+    public static final LengthPrefixedStructuredDataType LENGTH_PREFIXED_STRUCTURED_DATA = new LengthPrefixedStructuredDataType(STRUCTURED_DATA);
+    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 ItemType1_20_5 LENGTH_PREFIXED_ITEM = new ItemType1_20_5(LENGTH_PREFIXED_STRUCTURED_DATA);
+    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_5 ENTITY_DATA_TYPES = new EntityDataTypes1_21_5(ITEM, 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/exception/CancelDecoderException.java

@@ -56,7 +56,7 @@ public class CancelDecoderException extends DecoderException implements CancelCo
     /**
      * Returns a cached CancelDecoderException or a new instance when {@link ViaManager#isDebug()} is true.
      *
-     * @param cause cause for being used when a new instance is creeated
+     * @param cause cause for being used when a new instance is created
      * @return a CancelDecoderException instance
      */
     public static CancelDecoderException generate(Throwable cause) {