5.4.0 Release

Is it 1.22? Is it 1.21.6? Who knows

.github/workflows/build.yml

@@ -1,6 +1,6 @@
 name: Java CI with Gradle
 
-on: [push, pull_request]
+on: [push, pull_request, workflow_dispatch]
 
 jobs:
   build:
@@ -26,7 +26,7 @@ jobs:
       run: ./gradlew build
     - name: Upload Artifacts to GitHub
       # Only upload on the preview repository as there is no CI job for it.
-      if: ${{ github.repository == 'ViaVersionDev' && github.ref_name == 'preview' }}
+      if: ${{ github.repository == 'ViaVersion/ViaVersionDev' && github.ref_name == 'preview' }}
       uses: actions/upload-artifact@v4
       with:
         name: Artifacts

.github/workflows/publish.yml

@@ -4,6 +4,7 @@ on:
     branches:
       - master
       - dev
+  workflow_dispatch:
 
 jobs:
   publish:

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/build.gradle.kts

@@ -29,7 +29,11 @@ dependencies {
     api(libs.snakeYaml)
 
     compileOnlyApi(libs.netty)
-    compileOnlyApi(libs.guava)
+    compileOnlyApi(libs.guava) {
+        exclude("com.google.errorprone", "error_prone_annotations")
+        exclude("org.jspecify", "jspecify")
+        exclude("com.google.j2objc", "j2objc-annotations")
+    }
     compileOnlyApi(libs.checkerQual)
 }
 

api/src/main/java-templates/com/viaversion/viaversion/util/VersionInfo.java

@@ -1,6 +1,6 @@
 /*
  * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
- * Copyright (C) 2016-2024 ViaVersion and contributors
+ * 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

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/configuration/ViaVersionConfig.java

@@ -285,6 +285,13 @@ public interface ViaVersionConfig extends Config {
      */
     boolean isSuppressConversionWarnings();
 
+    /**
+     * Should we hide errors that occur when trying to convert text components?
+     *
+     * @return true if enabled
+     */
+    boolean isSuppressTextComponentConversionWarnings();
+
     /**
      * Should we disable the 1.13 auto-complete feature to stop spam kicks? (for any server lower than 1.13)
      *

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

@@ -24,6 +24,7 @@ package com.viaversion.viaversion.api.connection;
 
 import com.viaversion.viaversion.api.configuration.ViaVersionConfig;
 import com.viaversion.viaversion.api.data.entity.EntityTracker;
+import com.viaversion.viaversion.api.data.item.ItemHasher;
 import com.viaversion.viaversion.api.minecraft.ClientWorld;
 import com.viaversion.viaversion.api.protocol.Protocol;
 import com.viaversion.viaversion.api.protocol.packet.PacketTracker;
@@ -99,6 +100,23 @@ public interface UserConnection {
      */
     void addEntityTracker(Class<? extends Protocol> protocolClass, EntityTracker tracker);
 
+    /**
+     * Adds an item hasher to the user connection.
+     *
+     * @param protocolClass protocol class
+     * @param itemHasher   item hasher
+     */
+    void addItemHasher(Class<? extends Protocol> protocolClass, ItemHasher itemHasher);
+
+    /**
+     * Returns the item hasher by the given protocol class if present.
+     *
+     * @param protocolClass protocol class
+     * @param <T>           item hasher type
+     * @return item hasher if present
+     */
+    @Nullable <T extends ItemHasher> T getItemHasher(Class<? extends Protocol> protocolClass);
+
     /**
      * Returns the client world by the given protocol class if present.
      *
@@ -319,23 +337,35 @@ 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/data/entity/EntityTracker.java

@@ -123,6 +123,20 @@ public interface EntityTracker {
      */
     void setClientEntityId(int clientEntityId);
 
+    /**
+     * Returns whether the client player has the "insta build" ability, usually from creative mode.
+     *
+     * @return whether the client player can insta build
+     */
+    boolean canInstaBuild();
+
+    /**
+     * Sets whether the client player has the "insta build" ability, usually from creative mode.
+     *
+     * @param instaBuild whether the client player can insta build
+     */
+    void setInstaBuild(boolean instaBuild);
+
     /**
      * Returns the current world section height (block height / 16).
      * This is always 16 for sub 1.17 worlds.

api/src/main/java/com/viaversion/viaversion/api/data/item/ItemHasher.java

@@ -0,0 +1,51 @@
+/*
+ * 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.data.item;
+
+import java.util.List;
+
+/**
+ * Used for converting items to hashed items and caching them for later use during serverbound packets.
+ * <p>
+ * Most of this stays in the internal module given non-permanent, imperfect caching as well as missing converters.
+ */
+public interface ItemHasher {
+
+    /**
+     * Returns whether this connection is currently processing a clientbound player inventory packet.
+     * <p>
+     * Used for checking when it is necessary to track/process item data hashes.
+     *
+     * @return true if processing a clientbound inventory packet, false otherwise
+     */
+    boolean isProcessingClientboundInventoryPacket();
+
+    void setProcessingClientboundInventoryPacket(boolean processingClientboundInventoryPacket);
+
+    /**
+     * Sets the enchantment registry for this connection.
+     *
+     * @param enchantments list of enchantment identifiers
+     */
+    void setEnchantments(List<String> enchantments);
+}

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/BlockChangeRecord1_16_2.java

@@ -58,7 +58,7 @@ public class BlockChangeRecord1_16_2 implements BlockChangeRecord {
 
     @Override
     public short getY(int chunkSectionY) {
-        Preconditions.checkArgument(chunkSectionY >= 0, "Invalid chunkSectionY: " + chunkSectionY);
+        Preconditions.checkArgument(chunkSectionY >= 0, "Invalid chunkSectionY: %s", chunkSectionY);
         return (short) ((chunkSectionY << 4) + sectionY);
     }
 

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/GameMode.java

@@ -24,22 +24,28 @@ package com.viaversion.viaversion.api.minecraft;
 
 public enum GameMode {
 
-    NOT_SET(""),
-    SURVIVAL("Survival Mode"),
-    CREATIVE("Creative Mode"),
-    ADVENTURE("Adventure Mode"),
-    SPECTATOR("Spectator Mode");
+    NOT_SET("", -1),
+    SURVIVAL("Survival Mode", 0),
+    CREATIVE("Creative Mode", 1),
+    ADVENTURE("Adventure Mode", 2),
+    SPECTATOR("Spectator Mode", 3);
 
     private final String text;
+    private final int id;
 
-    GameMode(String text) {
+    GameMode(String text, final int id) {
         this.text = text;
+        this.id = id;
     }
 
     public String text() {
         return text;
     }
 
+    public int id() {
+        return id;
+    }
+
     public static GameMode getById(int id) {
         return switch (id) {
             case -1 -> NOT_SET;

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

@@ -22,11 +22,31 @@
  */
 package com.viaversion.viaversion.api.minecraft;
 
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
 import java.util.UUID;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 public record GameProfile(@Nullable String name, @Nullable UUID id, Property[] properties) {
 
+    public GameProfile(@Nullable final String name, @Nullable final UUID id) {
+        this(name, id, new Property[0]);
+    }
+
+    public Map<String, List<Property>> propertiesMap() {
+        final Map<String, List<Property>> map = new HashMap<>();
+        for (Property property : properties) {
+            map.computeIfAbsent(property.name(), k -> new ArrayList<>()).add(property);
+        }
+        return map;
+    }
+
     public record Property(String name, String value, @Nullable String signature) {
+
+        public Property(final String name, final String value) {
+            this(name, value, null);
+        }
     }
 }

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

@@ -23,6 +23,7 @@
 package com.viaversion.viaversion.api.minecraft;
 
 import it.unimi.dsi.fastutil.ints.Int2IntFunction;
+import java.util.function.Function;
 
 public interface Holder<T> {
 
@@ -89,4 +90,12 @@ public interface Holder<T> {
      * @return a new holder with the id rewritten, or self
      */
     Holder<T> updateId(final Int2IntFunction rewriteFunction);
+
+    /**
+     * Returns a new holder with the value rewritten using the given function, or self if this is an id holder or the value did not change.
+     *
+     * @param rewriteFunction the function to rewrite the value
+     * @return a new holder with the value rewritten, or self
+     */
+    Holder<T> updateValue(final Function<T, T> rewriteFunction);
 }

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

@@ -67,11 +67,17 @@ final class HolderSetImpl {
 
         @Override
         public HolderSet rewrite(final Int2IntFunction idRewriter) {
+            // Filter out negative ids as they would come from missing VB mapping data. This happens especially
+            // with block ids which are not mapped and thus written as -1 so VV rewriters can cancel them nicely.
             final int[] mappedIds = new int[ids.length];
-            for (int i = 0; i < mappedIds.length; i++) {
-                mappedIds[i] = idRewriter.applyAsInt(ids[i]);
+            int validCount = 0;
+            for (final int id : ids) {
+                final int mappedId = idRewriter.applyAsInt(id);
+                if (mappedId != -1) {
+                    mappedIds[validCount++] = mappedId;
+                }
             }
-            return new Ids(mappedIds);
+            return new Ids(validCount == ids.length ? mappedIds : Arrays.copyOf(mappedIds, validCount));
         }
 
         @Override

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

@@ -24,6 +24,7 @@ package com.viaversion.viaversion.api.minecraft;
 
 import com.google.common.base.Preconditions;
 import it.unimi.dsi.fastutil.ints.Int2IntFunction;
+import java.util.function.Function;
 
 record IdHolder<T>(int id) implements Holder<T> {
 
@@ -57,4 +58,9 @@ record IdHolder<T>(int id) implements Holder<T> {
         }
         return Holder.of(rewrittenId);
     }
+
+    @Override
+    public Holder<T> updateValue(final Function<T, T> rewriteFunction) {
+        return this;
+    }
 }

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, Copyable.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/ValueHolder.java

@@ -23,6 +23,7 @@
 package com.viaversion.viaversion.api.minecraft;
 
 import it.unimi.dsi.fastutil.ints.Int2IntFunction;
+import java.util.function.Function;
 
 record ValueHolder<T>(T value) implements Holder<T> {
 
@@ -45,4 +46,10 @@ record ValueHolder<T>(T value) implements Holder<T> {
     public Holder<T> updateId(final Int2IntFunction rewriteFunction) {
         return this;
     }
+
+    @Override
+    public Holder<T> updateValue(final Function<T, T> rewriteFunction) {
+        final T rewrittenValue = rewriteFunction.apply(value);
+        return rewrittenValue != value ? Holder.of(rewrittenValue) : this;
+    }
 }

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/codec/CodecContext.java

@@ -0,0 +1,54 @@
+/*
+ * 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.codec;
+
+import com.viaversion.viaversion.api.data.MappingData;
+import com.viaversion.viaversion.api.minecraft.data.StructuredDataKey;
+import com.viaversion.viaversion.util.Key;
+import java.util.List;
+
+public interface CodecContext {
+
+    RegistryAccess registryAccess();
+
+    boolean mapped();
+
+    boolean isSupported(StructuredDataKey<?> key);
+
+    interface RegistryAccess {
+
+        Key item(int id);
+
+        Key enchantment(int id);
+
+        Key attributeModifier(int id);
+
+        Key dataComponentType(int id);
+
+        static RegistryAccess of(final List<String> enchantments, final MappingData mappingData) {
+            return new RegistryAccessImpl(enchantments, mappingData);
+        }
+
+        RegistryAccess withMapped(boolean mapped);
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/codec/Ops.java

@@ -0,0 +1,133 @@
+/*
+ * 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.codec;
+
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.Types;
+import java.util.Objects;
+import java.util.function.Consumer;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+public interface Ops {
+
+    CodecContext context();
+
+    void writeByte(byte b);
+
+    void writeBytes(byte[] array);
+
+    void writeBoolean(boolean b);
+
+    void writeShort(short s);
+
+    void writeString(CharSequence sequence);
+
+    void writeInt(int i);
+
+    void writeLong(long l);
+
+    void writeFloat(float f);
+
+    void writeDouble(double d);
+
+    void writeInts(int[] array);
+
+    void writeLongs(long[] array);
+
+    void writeList(Consumer<ListSerializer> consumer);
+
+    void writeMap(Consumer<MapSerializer> consumer);
+
+    <V> void write(final Type<V> type, final V value);
+
+    interface ListSerializer {
+
+        <V> ListSerializer write(Type<V> valueType, V value);
+
+        ListSerializer writeList(Consumer<ListSerializer> consumer);
+
+        ListSerializer writeMap(Consumer<MapSerializer> consumer);
+    }
+
+    interface MapSerializer {
+
+        <K, V> MapSerializer write(Type<K> keyType, K key, Type<V> valueType, V value);
+
+        default <V> MapSerializer write(final String key, final Type<V> type, final V value) {
+            write(Types.STRING, key, type, value);
+            return this;
+        }
+
+        /**
+         * Writes the given value or default value if the value is null.
+         *
+         * @param key map key
+         * @param type type of the value
+         * @param value the value to write, or null
+         * @param def default value to write if the value is null
+         * @return self
+         * @param <V> value type
+         */
+        default <V> MapSerializer write(final String key, final Type<V> type, @Nullable final V value, final V def) {
+            write(Types.STRING, key, type, value != null ? value : def);
+            return this;
+        }
+
+        /**
+         * Writes the given value if it is not null.
+         *
+         * @param key map key
+         * @param type type of the value
+         * @param value the value to write, or null
+         * @return self
+         * @param <V> value type
+         */
+        default <V> MapSerializer writeOptional(final String key, final Type<V> type, @Nullable final V value) {
+            if (value != null) {
+                write(Types.STRING, key, type, value);
+            }
+            return this;
+        }
+
+        /**
+         * Writes the given value if it is not null and not equal to the default value.
+         *
+         * @param key map key
+         * @param type type of the value
+         * @param value the value to write, or null
+         * @param def default value to compare against
+         * @return self
+         * @param <V> value type
+         */
+        default <V> MapSerializer writeOptional(final String key, final Type<V> type, @Nullable final V value, final V def) {
+            if (value != null && !Objects.deepEquals(value, def)) {
+                write(Types.STRING, key, type, value);
+            }
+            return this;
+        }
+
+        MapSerializer writeList(String key, Consumer<ListSerializer> consumer);
+
+        MapSerializer writeMap(String key, Consumer<MapSerializer> consumer);
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/codec/RegistryAccessImpl.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.codec;
+
+import com.viaversion.viaversion.api.data.FullMappings;
+import com.viaversion.viaversion.api.data.MappingData;
+import com.viaversion.viaversion.util.Key;
+import java.util.List;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+final class RegistryAccessImpl implements CodecContext.RegistryAccess {
+    private final List<String> enchantments;
+    private final MappingData mappingData;
+    private final boolean mapped;
+
+    RegistryAccessImpl(final List<String> enchantments, final MappingData mappingData) {
+        this.enchantments = enchantments;
+        this.mappingData = mappingData;
+        this.mapped = false;
+    }
+
+    private RegistryAccessImpl(final List<String> enchantments, final MappingData mappingData, final boolean mapped) {
+        this.enchantments = enchantments;
+        this.mappingData = mappingData;
+        this.mapped = mapped;
+    }
+
+    @Override
+    public Key item(final int id) {
+        return key(mappingData.getFullItemMappings(), id);
+    }
+
+    @Override
+    public Key enchantment(final int id) {
+        final String identifier = id >= 0 && id < this.enchantments.size() ? this.enchantments.get(id) : null;
+        return key(identifier, id);
+    }
+
+    @Override
+    public Key attributeModifier(final int id) {
+        return key(mappingData.getAttributeMappings(), id);
+    }
+
+    @Override
+    public Key dataComponentType(final int id) {
+        return key(mappingData.getDataComponentSerializerMappings(), id);
+    }
+
+    private Key key(final FullMappings mappings, final int id) {
+        final String identifier = mapped ? mappings.mappedIdentifier(id) : mappings.identifier(id);
+        return key(identifier, id);
+    }
+
+    private Key key(@Nullable final String identifier, final int id) {
+        return identifier != null ? Key.of(identifier) : Key.of("viaversion", "unknown/" + id);
+    }
+
+    @Override
+    public CodecContext.RegistryAccess withMapped(final boolean mapped) {
+        return this.mapped == mapped ? this : new RegistryAccessImpl(this.enchantments, this.mappingData, mapped);
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/codec/hash/Hasher.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.codec.hash;
+
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
+
+/**
+ * Hash operations. Note that this is different from Vanilla codecs, where this
+ * instead acts as a (re-usable) hasher directly rather than each method having
+ * self-contained return values.
+ */
+public interface Hasher extends Ops {
+
+    /**
+     * Returns the current hash value.
+     *
+     * @return the current hash value
+     */
+    int hash();
+
+    /**
+     * Resets the hasher to its initial state.
+     */
+    void reset();
+}

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

@@ -23,6 +23,7 @@
 package com.viaversion.viaversion.api.minecraft.data;
 
 import com.google.common.base.Preconditions;
+import com.viaversion.viaversion.util.Copyable;
 import io.netty.buffer.ByteBuf;
 import java.util.Objects;
 
@@ -59,6 +60,11 @@ final class FilledStructuredData<T> implements StructuredData<T> {
         return key;
     }
 
+    @Override
+    public StructuredData<T> copy() {
+        return new FilledStructuredData<>(this.key, Copyable.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;
     }
@@ -263,6 +284,10 @@ public final class StructuredDataContainer {
         return data;
     }
 
+    public boolean isEmpty() {
+        return data.isEmpty();
+    }
+
     @Override
     public String toString() {
         return "StructuredDataContainer{" +

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

@@ -24,10 +24,15 @@ 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.item.Item;
+import com.viaversion.viaversion.api.minecraft.PaintingVariant;
+import com.viaversion.viaversion.api.minecraft.SoundEvent;
+import com.viaversion.viaversion.api.minecraft.data.version.StructuredDataKeys1_20_5;
+import com.viaversion.viaversion.api.minecraft.data.version.StructuredDataKeys1_21_2;
+import com.viaversion.viaversion.api.minecraft.data.version.StructuredDataKeys1_21_5;
 import com.viaversion.viaversion.api.minecraft.item.data.AdventureModePredicate;
 import com.viaversion.viaversion.api.minecraft.item.data.ArmorTrim;
 import com.viaversion.viaversion.api.minecraft.item.data.AttributeModifiers1_20_5;
@@ -35,14 +40,16 @@ 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;
 import com.viaversion.viaversion.api.minecraft.item.data.DeathProtection;
 import com.viaversion.viaversion.api.minecraft.item.data.DyedColor;
+import com.viaversion.viaversion.api.minecraft.item.data.Enchantable;
 import com.viaversion.viaversion.api.minecraft.item.data.Enchantments;
+import com.viaversion.viaversion.api.minecraft.item.data.EnumTypes;
 import com.viaversion.viaversion.api.minecraft.item.data.Equippable;
-import com.viaversion.viaversion.api.minecraft.item.data.FilterableString;
 import com.viaversion.viaversion.api.minecraft.item.data.FireworkExplosion;
 import com.viaversion.viaversion.api.minecraft.item.data.Fireworks;
 import com.viaversion.viaversion.api.minecraft.item.data.FoodProperties1_20_5;
@@ -53,41 +60,60 @@ 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.TropicalFishPattern;
 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.WritableBook;
 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.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.EitherType;
+import com.viaversion.viaversion.api.type.types.version.VersionedTypes;
+import com.viaversion.viaversion.util.Either;
+import com.viaversion.viaversion.util.Key;
 import com.viaversion.viaversion.util.Unit;
 
+/**
+ * Holds data component keys.
+ *
+ * @param identifier string identifier
+ * @param type data type
+ * @param <T> data type
+ * @see VersionedTypes
+ */
 public record StructuredDataKey<T>(String identifier, Type<T> type) {
 
     public static final StructuredDataKey<CompoundTag> CUSTOM_DATA = new StructuredDataKey<>("custom_data", Types.COMPOUND_TAG);
     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<Key> ITEM_MODEL = new StructuredDataKey<>("item_model", Types.RESOURCE_LOCATION);
     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<Integer> RARITY = new StructuredDataKey<>("rarity", EnumTypes.RARITY);
+    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);
+    // 1.21.5+ predicates are in their own key classes
+    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_BREAK1_20_5 = new StructuredDataKey<>("can_break", AdventureModePredicate.TYPE1_20_5);
     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<AttributeModifiers1_21> ATTRIBUTE_MODIFIERS1_21_6 = new StructuredDataKey<>("attribute_modifiers", AttributeModifiers1_21.TYPE1_21_6);
     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);
@@ -96,65 +122,98 @@ public record StructuredDataKey<T>(String identifier, Type<T> type) {
     public static final StructuredDataKey<FoodProperties1_20_5> FOOD1_21 = new StructuredDataKey<>("food", FoodProperties1_20_5.TYPE1_21);
     public static final StructuredDataKey<FoodProperties1_21_2> FOOD1_21_2 = new StructuredDataKey<>("food", FoodProperties1_21_2.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<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<Integer> ENCHANTABLE = new StructuredDataKey<>("enchantable", Types.VAR_INT);
-    public static final StructuredDataKey<Equippable> EQUIPPABLE = new StructuredDataKey<>("equippable", Equippable.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<Enchantable> ENCHANTABLE = new StructuredDataKey<>("enchantable", Enchantable.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<Equippable> EQUIPPABLE1_21_6 = new StructuredDataKey<>("equippable", Equippable.TYPE1_21_6);
     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<Key> TOOLTIP_STYLE = new StructuredDataKey<>("tooltip_style", Types.RESOURCE_LOCATION);
     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);
     public static final StructuredDataKey<Integer> MAP_POST_PROCESSING = new StructuredDataKey<>("map_post_processing", Types.VAR_INT);
-    public static final StructuredDataKey<Item[]> CHARGED_PROJECTILES1_20_5 = new StructuredDataKey<>("charged_projectiles", Types1_20_5.ITEM_ARRAY);
-    public static final StructuredDataKey<Item[]> CHARGED_PROJECTILES1_21 = new StructuredDataKey<>("charged_projectiles", Types1_21.ITEM_ARRAY);
-    public static final StructuredDataKey<Item[]> 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[]> 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<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<WritableBook> WRITABLE_BOOK_CONTENT = new StructuredDataKey<>("writable_book_content", WritableBook.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<Key> PROVIDES_BANNER_PATTERNS = new StructuredDataKey<>("provides_banner_patterns", Types.TAG_KEY);
     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);
     public static final StructuredDataKey<Fireworks> FIREWORKS = new StructuredDataKey<>("fireworks", Fireworks.TYPE);
     public static final StructuredDataKey<GameProfile> PROFILE = new StructuredDataKey<>("profile", Types.GAME_PROFILE);
-    public static final StructuredDataKey<String> NOTE_BLOCK_SOUND = new StructuredDataKey<>("note_block_sound", Types.STRING);
+    public static final StructuredDataKey<Key> NOTE_BLOCK_SOUND = new StructuredDataKey<>("note_block_sound", Types.RESOURCE_LOCATION);
     public static final StructuredDataKey<BannerPatternLayer[]> BANNER_PATTERNS = new StructuredDataKey<>("banner_patterns", BannerPatternLayer.ARRAY_TYPE);
-    public static final StructuredDataKey<Integer> BASE_COLOR = new StructuredDataKey<>("base_color", Types.VAR_INT);
+    public static final StructuredDataKey<Integer> BASE_COLOR = new StructuredDataKey<>("base_color", EnumTypes.DYE_COLOR);
     public static final StructuredDataKey<PotDecorations> POT_DECORATIONS = new StructuredDataKey<>("pot_decorations", PotDecorations.TYPE);
-    public static final StructuredDataKey<Item[]> CONTAINER1_20_5 = new StructuredDataKey<>("container", Types1_20_5.ITEM_ARRAY);
-    public static final StructuredDataKey<Item[]> CONTAINER1_21 = new StructuredDataKey<>("container", Types1_21.ITEM_ARRAY);
-    public static final StructuredDataKey<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<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", EnumTypes.VILLAGER_TYPE);
+    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", EnumTypes.DYE_COLOR);
+    public static final StructuredDataKey<Integer> FOX_VARIANT = new StructuredDataKey<>("fox/variant", EnumTypes.FOX_VARIANT);
+    public static final StructuredDataKey<Integer> SALMON_SIZE = new StructuredDataKey<>("salmon/size", EnumTypes.SALMON_VARIANT);
+    public static final StructuredDataKey<Integer> PARROT_VARIANT = new StructuredDataKey<>("parrot/variant", EnumTypes.PARROT_VARIANT);
+    public static final StructuredDataKey<TropicalFishPattern> TROPICAL_FISH_PATTERN = new StructuredDataKey<>("tropical_fish/pattern", TropicalFishPattern.TYPE);
+    public static final StructuredDataKey<Integer> TROPICAL_FISH_BASE_COLOR = new StructuredDataKey<>("tropical_fish/base_color", EnumTypes.DYE_COLOR);
+    public static final StructuredDataKey<Integer> TROPICAL_FISH_PATTERN_COLOR = new StructuredDataKey<>("tropical_fish/pattern_color", EnumTypes.DYE_COLOR);
+    public static final StructuredDataKey<Integer> MOOSHROOM_VARIANT = new StructuredDataKey<>("mooshroom/variant", EnumTypes.MUSHROOM_COW_VARIANT);
+    public static final StructuredDataKey<Integer> RABBIT_VARIANT = new StructuredDataKey<>("rabbit/variant", EnumTypes.RABBIT_VARIANT);
+    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", EnumTypes.HORSE_VARIANT);
+    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", EnumTypes.LLAMA_VARIANT);
+    public static final StructuredDataKey<Integer> AXOLOTL_VARIANT = new StructuredDataKey<>("axolotl/variant", EnumTypes.AXOLOTL_VARIANT);
+    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", EnumTypes.DYE_COLOR);
+    public static final StructuredDataKey<Integer> SHEEP_COLOR = new StructuredDataKey<>("sheep/color", EnumTypes.DYE_COLOR);
+    public static final StructuredDataKey<Integer> SHULKER_COLOR = new StructuredDataKey<>("shulker/color", EnumTypes.DYE_COLOR);
+
+    // These are only safe to use after protocol loading
+    public static final StructuredDataKeys1_20_5 V1_20_5 = VersionedTypes.V1_20_5.structuredDataKeys();
+    public static final StructuredDataKeys1_20_5 V1_21 = VersionedTypes.V1_21.structuredDataKeys();
+    public static final StructuredDataKeys1_21_2 V1_21_2 = VersionedTypes.V1_21_2.structuredDataKeys();
+    public static final StructuredDataKeys1_21_2 V1_21_4 = VersionedTypes.V1_21_4.structuredDataKeys();
+    public static final StructuredDataKeys1_21_5 V1_21_5 = VersionedTypes.V1_21_5.structuredDataKeys();
+    public static final StructuredDataKeys1_21_5 V1_21_6 = VersionedTypes.V1_21_6.structuredDataKeys();
 
     @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/data/version/StructuredDataKeys1_20_5.java

@@ -0,0 +1,40 @@
+/*
+ * 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.version;
+
+import com.viaversion.viaversion.api.minecraft.data.StructuredDataKey;
+import com.viaversion.viaversion.api.minecraft.item.Item;
+import com.viaversion.viaversion.api.type.types.version.VersionedTypesHolder;
+
+public class StructuredDataKeys1_20_5 extends VersionedStructuredDataKeys {
+
+    public final StructuredDataKey<Item[]> container;
+    public final StructuredDataKey<Item[]> chargedProjectiles;
+    public final StructuredDataKey<Item[]> bundleContents;
+
+    public StructuredDataKeys1_20_5(final VersionedTypesHolder types) {
+        this.container = add("container", types.itemArray());
+        this.chargedProjectiles = add("charged_projectiles", types.itemArray());
+        this.bundleContents = add("bundle_contents", types.itemArray());
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/data/version/StructuredDataKeys1_21_2.java

@@ -0,0 +1,43 @@
+/*
+ * 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.version;
+
+import com.viaversion.viaversion.api.minecraft.data.StructuredDataKey;
+import com.viaversion.viaversion.api.minecraft.item.Item;
+import com.viaversion.viaversion.api.minecraft.item.data.ContainterContents.ContainerContentsType;
+import com.viaversion.viaversion.api.type.types.version.VersionedTypesHolder;
+
+public class StructuredDataKeys1_21_2 extends VersionedStructuredDataKeys {
+
+    public final StructuredDataKey<Item[]> container;
+    public final StructuredDataKey<Item[]> chargedProjectiles;
+    public final StructuredDataKey<Item[]> bundleContents;
+    public final StructuredDataKey<Item> useRemainder;
+
+    public StructuredDataKeys1_21_2(final VersionedTypesHolder types) {
+        this.container = add("container", new ContainerContentsType(types.item()));
+        this.chargedProjectiles = add("charged_projectiles", types.itemArray());
+        this.bundleContents = add("bundle_contents", types.itemArray());
+        this.useRemainder = add("use_remainder", types.item());
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/data/version/StructuredDataKeys1_21_5.java

@@ -0,0 +1,43 @@
+/*
+ * 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.version;
+
+import com.viaversion.viaversion.api.minecraft.data.StructuredDataKey;
+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.type.types.version.VersionedTypesHolder;
+
+public class StructuredDataKeys1_21_5 extends StructuredDataKeys1_21_2 {
+
+    public final StructuredDataKey<AdventureModePredicate> canPlaceOn;
+    public final StructuredDataKey<AdventureModePredicate> canBreak;
+
+    public StructuredDataKeys1_21_5(final VersionedTypesHolder types) {
+        super(types);
+        final AdventureModePredicateType1_21_5 adventureModePredicateType = new AdventureModePredicateType1_21_5(types.structuredDataArray());
+        this.canPlaceOn = add("can_place_on", adventureModePredicateType);
+        this.canBreak = add("can_break", adventureModePredicateType);
+        this.unsupportedForOps.add(this.canPlaceOn);
+        this.unsupportedForOps.add(this.canBreak);
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/data/version/VersionedStructuredDataKeys.java

@@ -0,0 +1,50 @@
+/*
+ * 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.version;
+
+import com.viaversion.viaversion.api.minecraft.data.StructuredDataKey;
+import com.viaversion.viaversion.api.type.Type;
+import it.unimi.dsi.fastutil.objects.ReferenceArraySet;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Set;
+
+public abstract class VersionedStructuredDataKeys {
+
+    private final List<StructuredDataKey<?>> keys = new ArrayList<>();
+    protected final Set<StructuredDataKey<?>> unsupportedForOps = new ReferenceArraySet<>();
+
+    protected <T> StructuredDataKey<T> add(final String identifier, final Type<T> type) {
+        final StructuredDataKey<T> key = new StructuredDataKey<>(identifier, type);
+        this.keys.add(key);
+        return key;
+    }
+
+    public List<StructuredDataKey<?>> keys() {
+        return this.keys;
+    }
+
+    public boolean supportsOps(final StructuredDataKey<?> key) {
+        return !unsupportedForOps.contains(key);
+    }
+}

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_21_6.java

@@ -0,0 +1,318 @@
+/*
+ * 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_6 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),
+    HAPPY_GHAST(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_6(final EntityType parent) {
+        this.parent = parent;
+        this.identifier = Key.namespaced(name().toLowerCase(Locale.ROOT));
+    }
+
+    EntityTypes1_21_6(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_20_5.java

@@ -22,12 +22,9 @@
  */
 package com.viaversion.viaversion.api.minecraft.entitydata.types;
 
-import com.viaversion.viaversion.api.minecraft.Particle;
 import com.viaversion.viaversion.api.minecraft.entitydata.EntityDataType;
 import com.viaversion.viaversion.api.type.Types;
-import com.viaversion.viaversion.api.type.types.ArrayType;
-import com.viaversion.viaversion.api.type.types.misc.ParticleType;
-import com.viaversion.viaversion.api.type.types.version.Types1_20_5;
+import com.viaversion.viaversion.api.type.types.version.VersionedTypesHolder;
 
 public final class EntityDataTypes1_20_5 extends AbstractEntityDataTypes {
 
@@ -38,7 +35,7 @@ public final class EntityDataTypes1_20_5 extends AbstractEntityDataTypes {
     public final EntityDataType stringType = add(4, Types.STRING);
     public final EntityDataType componentType = add(5, Types.TAG);
     public final EntityDataType optionalComponentType = add(6, Types.OPTIONAL_TAG);
-    public final EntityDataType itemType = add(7, Types1_20_5.ITEM);
+    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);
@@ -63,9 +60,10 @@ public final class EntityDataTypes1_20_5 extends AbstractEntityDataTypes {
     public final EntityDataType vector3FType = add(29, Types.VECTOR3F);
     public final EntityDataType quaternionType = add(30, Types.QUATERNION);
 
-    public EntityDataTypes1_20_5(final ParticleType particleType, final ArrayType<Particle> particlesType) {
+    public EntityDataTypes1_20_5(final VersionedTypesHolder types) {
         super(31);
-        this.particleType = add(17, particleType);
-        this.particlesType = add(18, particlesType);
+        this.itemType = add(7, types.item());
+        this.particleType = add(17, types.particle());
+        this.particlesType = add(18, types.particles());
     }
 }

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

@@ -23,14 +23,10 @@
 package com.viaversion.viaversion.api.minecraft.entitydata.types;
 
 import com.viaversion.viaversion.api.minecraft.PaintingVariant;
-import com.viaversion.viaversion.api.minecraft.Particle;
 import com.viaversion.viaversion.api.minecraft.WolfVariant;
 import com.viaversion.viaversion.api.minecraft.entitydata.EntityDataType;
-import com.viaversion.viaversion.api.minecraft.item.Item;
-import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
-import com.viaversion.viaversion.api.type.types.ArrayType;
-import com.viaversion.viaversion.api.type.types.misc.ParticleType;
+import com.viaversion.viaversion.api.type.types.version.VersionedTypesHolder;
 
 public final class EntityDataTypes1_21 extends AbstractEntityDataTypes {
 
@@ -66,10 +62,10 @@ public final class EntityDataTypes1_21 extends AbstractEntityDataTypes {
     public final EntityDataType vector3FType = add(29, Types.VECTOR3F);
     public final EntityDataType quaternionType = add(30, Types.QUATERNION);
 
-    public EntityDataTypes1_21(final Type<Item> itemType, final ParticleType particleType, final ArrayType<Particle> particlesType) {
+    public EntityDataTypes1_21(final VersionedTypesHolder types) {
         super(31);
-        this.itemType = add(7, itemType);
-        this.particleType = add(17, particleType);
-        this.particlesType = add(18, particlesType);
+        this.itemType = add(7, types.item());
+        this.particleType = add(17, types.particle());
+        this.particlesType = add(18, types.particles());
     }
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/entitydata/types/EntityDataTypes1_21_2.java

@@ -23,13 +23,10 @@
 package com.viaversion.viaversion.api.minecraft.entitydata.types;
 
 import com.viaversion.viaversion.api.minecraft.PaintingVariant;
-import com.viaversion.viaversion.api.minecraft.Particle;
 import com.viaversion.viaversion.api.minecraft.WolfVariant;
 import com.viaversion.viaversion.api.minecraft.entitydata.EntityDataType;
-import com.viaversion.viaversion.api.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;
+import com.viaversion.viaversion.api.type.types.version.VersionedTypesHolder;
 
 public final class EntityDataTypes1_21_2 extends AbstractEntityDataTypes {
 
@@ -65,10 +62,10 @@ public final class EntityDataTypes1_21_2 extends AbstractEntityDataTypes {
     public final EntityDataType vector3FType = add(29, Types.VECTOR3F);
     public final EntityDataType quaternionType = add(30, Types.QUATERNION);
 
-    public EntityDataTypes1_21_2(final Type<Item> itemType, final ParticleType particleType, final Type<Particle[]> particlesType) {
+    public EntityDataTypes1_21_2(final VersionedTypesHolder types) {
         super(31);
-        this.itemType = add(7, itemType);
-        this.particleType = add(17, particleType);
-        this.particlesType = add(18, particlesType);
+        this.itemType = add(7, types.item());
+        this.particleType = add(17, types.particle());
+        this.particlesType = add(18, types.particles());
     }
 }

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

@@ -0,0 +1,74 @@
+/*
+ * 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.entitydata.EntityDataType;
+import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.api.type.types.version.VersionedTypesHolder;
+
+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 VersionedTypesHolder types) {
+        super(35);
+        this.itemType = add(7, types.item());
+        this.particleType = add(17, types.particle());
+        this.particlesType = add(18, types.particles());
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/HashedItem.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;
+
+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();
+
+    @Override
+    HashedItem copy();
+}

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

@@ -0,0 +1,115 @@
+/*
+ * 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 HashedItem copy() {
+        return new HashedStructuredItem(identifier, amount, new Int2IntOpenHashMap(dataHashes), new IntOpenHashSet(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 {
 
     /**
      * 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 +1,72 @@
+/*
+ * 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 com.viaversion.viaversion.util.Copyable;
+
+/**
+ * @see Item
+ * @see HashedItem
+ */
+public interface ItemBase extends Copyable {
+
+    /**
+     * 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;
+    }
+
+    @Override
+    ItemBase copy();
+}

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

@@ -22,32 +22,68 @@
  */
 package com.viaversion.viaversion.api.minecraft.item.data;
 
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.minecraft.data.StructuredData;
+import com.viaversion.viaversion.api.protocol.Protocol;
 import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.types.ArrayType;
+import com.viaversion.viaversion.util.Copyable;
+import com.viaversion.viaversion.util.Rewritable;
 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, Rewritable {
 
-    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 AdventureModePredicate rewrite(final Int2IntFunction blockIdRewriter) {
+    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);
+        }
+    }
+
+    @Override
+    public AdventureModePredicate rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
         final BlockPredicate[] predicates = new BlockPredicate[this.predicates.length];
         for (int i = 0; i < predicates.length; i++) {
-            predicates[i] = this.predicates[i].rewrite(blockIdRewriter);
+            predicates[i] = this.predicates[i].rewrite(connection, protocol, clientbound);
         }
         return new AdventureModePredicate(predicates, showInTooltip);
     }
+
+    @Override
+    public AdventureModePredicate copy() {
+        return new AdventureModePredicate(Copyable.copy(predicates), showInTooltip);
+    }
 }

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

@@ -22,18 +22,25 @@
  */
 package com.viaversion.viaversion.api.minecraft.item.data;
 
+import com.viaversion.viaversion.api.connection.UserConnection;
 import com.viaversion.viaversion.api.minecraft.Holder;
+import com.viaversion.viaversion.api.protocol.Protocol;
 import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.util.Rewritable;
 import io.netty.buffer.ByteBuf;
-import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 
-public record ArmorTrim(Holder<ArmorTrimMaterial> material, Holder<ArmorTrimPattern> pattern, boolean showInTooltip) {
+public record ArmorTrim(Holder<ArmorTrimMaterial> material, Holder<ArmorTrimPattern> pattern,
+                        boolean showInTooltip) implements Rewritable {
+
+    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 +48,7 @@ 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 +56,7 @@ 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 +64,7 @@ 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 +72,7 @@ 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);
         }
@@ -73,20 +80,35 @@ 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);
+        }
 
-    public ArmorTrim rewrite(final Int2IntFunction idRewriteFunction) {
+        @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);
+        }
+    };
+
+    @Override
+    public ArmorTrim rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
         Holder<ArmorTrimMaterial> material = this.material;
         if (material.isDirect()) {
-            material = Holder.of(material.value().rewrite(idRewriteFunction));
+            material = Holder.of(material.value().rewrite(connection, protocol, clientbound));
         }
 
         Holder<ArmorTrimPattern> pattern = this.pattern;
         if (pattern.isDirect()) {
-            pattern = Holder.of(pattern.value().rewrite(idRewriteFunction));
+            pattern = Holder.of(pattern.value().rewrite(connection, protocol, clientbound));
         }
         return new ArmorTrim(material, pattern, showInTooltip);
     }

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

@@ -23,20 +23,28 @@
 package com.viaversion.viaversion.api.minecraft.item.data;
 
 import com.viaversion.nbt.tag.Tag;
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.protocol.Protocol;
 import com.viaversion.viaversion.api.type.Types;
 import com.viaversion.viaversion.api.type.types.misc.HolderType;
+import com.viaversion.viaversion.util.Copyable;
+import com.viaversion.viaversion.util.Rewritable;
 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, Rewritable {
 
     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 +55,7 @@ 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 +81,6 @@ 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 +89,7 @@ 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 +115,6 @@ 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 +122,7 @@ 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 +147,44 @@ 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);
 
-    public ArmorTrimMaterial rewrite(final Int2IntFunction idRewriteFunction) {
-        return new ArmorTrimMaterial(assetName, idRewriteFunction.applyAsInt(itemId), itemModelIndex, overrideArmorMaterials, description);
+            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());
+        }
+    };
+
+    @Override
+    public ArmorTrimMaterial rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+        return new ArmorTrimMaterial(assetName, Rewritable.rewriteItem(protocol, clientbound, 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

@@ -23,14 +23,21 @@
 package com.viaversion.viaversion.api.minecraft.item.data;
 
 import com.viaversion.nbt.tag.Tag;
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.protocol.Protocol;
 import com.viaversion.viaversion.api.type.Types;
 import com.viaversion.viaversion.api.type.types.misc.HolderType;
+import com.viaversion.viaversion.util.Copyable;
+import com.viaversion.viaversion.util.Rewritable;
 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, Rewritable {
 
-    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 +55,30 @@ 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);
+        }
 
-    public ArmorTrimPattern rewrite(final Int2IntFunction idRewriteFunction) {
-        return new ArmorTrimPattern(assetName, idRewriteFunction.applyAsInt(itemId), 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());
+        }
+    };
+
+    @Override
+    public ArmorTrimPattern rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+        return new ArmorTrimPattern(assetName, Rewritable.rewriteItem(protocol, clientbound, 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(Copyable.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

@@ -22,41 +22,94 @@
  */
 package com.viaversion.viaversion.api.minecraft.item.data;
 
+import com.viaversion.nbt.tag.Tag;
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
 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 com.viaversion.viaversion.util.Key;
 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);
+            final AttributeModifier[] modifiers = AttributeModifier.ARRAY_TYPE1_21.read(buffer);
             final boolean showInTooltip = buffer.readBoolean();
             return new AttributeModifiers1_21(modifiers, showInTooltip);
         }
 
         @Override
         public void write(final ByteBuf buffer, final AttributeModifiers1_21 value) {
-            AttributeModifier.ARRAY_TYPE.write(buffer, value.modifiers());
+            AttributeModifier.ARRAY_TYPE1_21.write(buffer, value.modifiers());
             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_TYPE1_21.read(buffer);
+            return new AttributeModifiers1_21(modifiers);
+        }
+
+        @Override
+        public void write(final ByteBuf buffer, final AttributeModifiers1_21 value) {
+            AttributeModifier.ARRAY_TYPE1_21.write(buffer, value.modifiers());
+        }
+
+        @Override
+        public void write(final Ops ops, final AttributeModifiers1_21 value) {
+            ops.write(AttributeModifier.ARRAY_TYPE1_21, value.modifiers);
+        }
+    };
+    public static final Type<AttributeModifiers1_21> TYPE1_21_6 = new Type<>(AttributeModifiers1_21.class) {
+        @Override
+        public AttributeModifiers1_21 read(final ByteBuf buffer) {
+            final AttributeModifier[] modifiers = AttributeModifier.ARRAY_TYPE1_21_6.read(buffer);
+            return new AttributeModifiers1_21(modifiers);
+        }
+
+        @Override
+        public void write(final ByteBuf buffer, final AttributeModifiers1_21 value) {
+            AttributeModifier.ARRAY_TYPE1_21_6.write(buffer, value.modifiers());
+        }
+
+        @Override
+        public void write(final Ops ops, final AttributeModifiers1_21 value) {
+            ops.write(AttributeModifier.ARRAY_TYPE1_21_6, value.modifiers);
+        }
+    };
 
     public AttributeModifiers1_21 rewrite(final Int2IntFunction rewriteFunction) {
         final AttributeModifier[] modifiers = new AttributeModifier[this.modifiers.length];
         for (int i = 0; i < this.modifiers.length; i++) {
             final AttributeModifier modifier = this.modifiers[i];
-            modifiers[i] = new AttributeModifier(rewriteFunction.applyAsInt(modifier.attribute()), modifier.modifier(), modifier.slotType());
+            modifiers[i] = new AttributeModifier(rewriteFunction.applyAsInt(modifier.attribute()), modifier.modifier(), modifier.slotType(), modifier.display());
         }
         return new AttributeModifiers1_21(modifiers, showInTooltip);
     }
 
-    public record AttributeModifier(int attribute, ModifierData modifier, int slotType) {
+    @Override
+    public AttributeModifiers1_21 copy() {
+        return new AttributeModifiers1_21(Copyable.copy(modifiers), showInTooltip);
+    }
 
-        public static final Type<AttributeModifier> TYPE = new Type<>(AttributeModifier.class) {
+    public record AttributeModifier(int attribute, ModifierData modifier, int slotType, Display display) {
+        private static final String[] EQUIPMENT_SLOT_GROUPS = {"any", "mainhand", "offhand", "hand", "feet", "legs", "chest", "head", "armor", "body", "saddle"};
+        private static final String[] OPERATION = {"add_value", "add_multiplied_base", "add_multiplied_total"};
+
+        public AttributeModifier(final int attribute, final ModifierData modifier, final int slotType) {
+            this(attribute, modifier, slotType, Display.DEFAULT);
+        }
+
+        public static final Type<AttributeModifier> TYPE1_21 = new Type<>(AttributeModifier.class) {
             @Override
             public AttributeModifier read(final ByteBuf buffer) {
                 final int attribute = Types.VAR_INT.readPrimitive(buffer);
@@ -71,8 +124,62 @@ public record AttributeModifiers1_21(AttributeModifier[] modifiers, boolean show
                 ModifierData.TYPE.write(buffer, value.modifier);
                 Types.VAR_INT.writePrimitive(buffer, value.slotType);
             }
+
+            @Override
+            public void write(final Ops ops, final AttributeModifier value) {
+                final Key attribute = ops.context().registryAccess().attributeModifier(value.attribute);
+                ops.writeMap(map -> map
+                    .write("type", Types.RESOURCE_LOCATION, attribute)
+                    .write("id", Types.RESOURCE_LOCATION, Key.of(value.modifier.id()))
+                    .write("amount", Types.DOUBLE, value.modifier.amount)
+                    .write("operation", Types.STRING, OPERATION[value.modifier.operation()])
+                    .writeOptional("slot", Types.STRING, EQUIPMENT_SLOT_GROUPS[value.slotType()], "any"));
+            }
         };
-        public static final Type<AttributeModifier[]> ARRAY_TYPE = new ArrayType<>(TYPE);
+        public static final Type<AttributeModifier[]> ARRAY_TYPE1_21 = new ArrayType<>(TYPE1_21);
+
+        public static final Type<AttributeModifier> TYPE1_21_6 = new Type<>(AttributeModifier.class) {
+            @Override
+            public AttributeModifier read(final ByteBuf buffer) {
+                final int attribute = Types.VAR_INT.readPrimitive(buffer);
+                final ModifierData modifier = ModifierData.TYPE.read(buffer);
+                final int slot = Types.VAR_INT.readPrimitive(buffer);
+                final int displayType = Types.VAR_INT.readPrimitive(buffer);
+                final Display display = displayType == OverrideText.ID ? new OverrideText(Types.TAG.read(buffer)) : new Display(displayType);
+                return new AttributeModifier(attribute, modifier, slot, display);
+            }
+
+            @Override
+            public void write(final ByteBuf buffer, final AttributeModifier value) {
+                Types.VAR_INT.writePrimitive(buffer, value.attribute);
+                ModifierData.TYPE.write(buffer, value.modifier);
+                Types.VAR_INT.writePrimitive(buffer, value.slotType);
+                value.display.write(buffer);
+            }
+
+            @Override
+            public void write(final Ops ops, final AttributeModifier value) {
+                final Key attribute = ops.context().registryAccess().attributeModifier(value.attribute);
+                ops.writeMap(map -> {
+                    map.write("type", Types.RESOURCE_LOCATION, attribute)
+                        .write("id", Types.RESOURCE_LOCATION, Key.of(value.modifier.id()))
+                        .write("amount", Types.DOUBLE, value.modifier.amount)
+                        .write("operation", Types.STRING, OPERATION[value.modifier.operation()])
+                        .writeOptional("slot", Types.STRING, EQUIPMENT_SLOT_GROUPS[value.slotType()], "any");
+                    if (value.display.equals(Display.DEFAULT)) {
+                        return;
+                    }
+
+                    map.writeMap("display", display -> {
+                        display.write("type", Types.STRING, Display.DISPLAY_TYPES[value.display.id()]);
+                        if (value.display instanceof final OverrideText overrideText) {
+                            display.write("value", Types.TAG, overrideText.component);
+                        }
+                    });
+                });
+            }
+        };
+        public static final Type<AttributeModifier[]> ARRAY_TYPE1_21_6 = new ArrayType<>(TYPE1_21_6);
     }
 
     public record ModifierData(String id, double amount, int operation) {
@@ -94,4 +201,52 @@ public record AttributeModifiers1_21(AttributeModifier[] modifiers, boolean show
             }
         };
     }
+
+    public static class Display implements Copyable {
+        public static final String[] DISPLAY_TYPES = {"default", "hidden", "override_text"};
+        public static final Display DEFAULT = new Display(0);
+        private final int id;
+
+        public Display(final int id) {
+            this.id = id;
+        }
+
+        public int id() {
+            return this.id;
+        }
+
+        public void write(final ByteBuf buf) {
+            Types.VAR_INT.writePrimitive(buf, this.id);
+        }
+
+        @Override
+        public Display copy() {
+            return this;
+        }
+    }
+
+    public static final class OverrideText extends Display {
+        public static final int ID = 2;
+        private final Tag component;
+
+        public OverrideText(final Tag component) {
+            super(ID);
+            this.component = component;
+        }
+
+        public Tag component() {
+            return this.component;
+        }
+
+        @Override
+        public void write(final ByteBuf buf) {
+            super.write(buf);
+            Types.TAG.write(buf, this.component);
+        }
+
+        @Override
+        public OverrideText copy() {
+            return new OverrideText(this.component.copy());
+        }
+    }
 }

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

@@ -23,12 +23,14 @@
 package com.viaversion.viaversion.api.minecraft.item.data;
 
 import com.viaversion.nbt.tag.CompoundTag;
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
 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
@@ -45,7 +47,19 @@ public record Bee(CompoundTag entityData, int ticksInHive, int minTicksInHive) {
             Types.VAR_INT.writePrimitive(buffer, value.ticksInHive);
             Types.VAR_INT.writePrimitive(buffer, value.minTicksInHive);
         }
+
+        @Override
+        public void write(final Ops ops, final Bee value) {
+            ops.writeMap(map -> map
+                .writeOptional("entity_data", Types.COMPOUND_TAG, value.entityData, new CompoundTag())
+                .write("ticks_in_hive", Types.INT, value.ticksInHive)
+                .write("min_ticks_in_hive", Types.INT, value.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

@@ -23,24 +23,36 @@
 package com.viaversion.viaversion.api.minecraft.item.data;
 
 import com.viaversion.nbt.tag.CompoundTag;
+import com.viaversion.viaversion.api.connection.UserConnection;
 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.minecraft.data.predicate.DataComponentPredicate;
+import com.viaversion.viaversion.api.protocol.Protocol;
 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 com.viaversion.viaversion.util.Rewritable;
 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, Rewritable {
 
-    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, new DataComponentMatchers(new StructuredData[0], new DataComponentPredicate[0]));
+    }
+
+    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
@@ -55,14 +67,51 @@ 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 BlockPredicate rewrite(final Int2IntFunction blockIdRewriter) {
+    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);
+        }
+    }
+
+    @Override
+    public BlockPredicate rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
         if (holderSet == null || holderSet.hasTagKey()) {
             return this;
         }
 
-        final HolderSet updatedHolders = holderSet.rewrite(blockIdRewriter);
+        final HolderSet updatedHolders = holderSet.rewrite(Rewritable.blockRewriteFunction(protocol, clientbound));
         return new BlockPredicate(updatedHolders, propertyMatchers, tag);
     }
+
+    @Override
+    public BlockPredicate copy() {
+        return new BlockPredicate(holderSet, Copyable.copy(propertyMatchers), tag == null ? null : tag.copy());
+    }
 }

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

@@ -22,19 +22,21 @@
  */
 package com.viaversion.viaversion.api.minecraft.item.data;
 
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
 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));
             }
@@ -49,6 +51,19 @@ public record BlockStateProperties(Map<String, String> properties) {
                 Types.STRING.write(buffer, entry.getValue());
             }
         }
+
+        @Override
+        public void write(final Ops ops, final BlockStateProperties value) {
+            ops.writeMap(map -> {
+                for (final Map.Entry<String, String> entry : value.properties.entrySet()) {
+                    map.write(Types.STRING, entry.getKey(), Types.STRING, entry.getValue());
+                }
+            });
+        }
     };
 
+    @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

@@ -22,15 +22,20 @@
  */
 package com.viaversion.viaversion.api.minecraft.item.data;
 
+import com.viaversion.viaversion.api.connection.UserConnection;
 import com.viaversion.viaversion.api.minecraft.Holder;
 import com.viaversion.viaversion.api.minecraft.SoundEvent;
+import com.viaversion.viaversion.api.protocol.Protocol;
 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 com.viaversion.viaversion.util.Rewritable;
 import io.netty.buffer.ByteBuf;
 
 public record Consumable1_21_2(float consumeSeconds, int animationType, Holder<SoundEvent> sound,
-                               boolean hasConsumeParticles, ConsumeEffect<?>[] consumeEffects) {
+                               boolean hasConsumeParticles,
+                               ConsumeEffect<?>[] consumeEffects) implements Copyable, Rewritable {
 
     public static final Type<?>[] EFFECT_TYPES = {
         ApplyStatusEffects.TYPE,
@@ -108,4 +113,15 @@ public record Consumable1_21_2(float consumeSeconds, int animationType, Holder<S
             }
         };
     }
+
+    @Override
+    public Consumable1_21_2 rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+        final Holder<SoundEvent> soundHolder = this.sound.updateId(Rewritable.soundRewriteFunction(protocol, clientbound));
+        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, Copyable.copy(consumeEffects));
+    }
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/ContainterContents.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.item.data;
+
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
+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.ArrayType;
+
+public final class ContainterContents {
+
+    // Just write it as Item[] directly, makes processing easier (until op reading is needed)
+    public static final class ContainerContentsType extends ArrayType<Item> {
+        private final Type<Item> itemType;
+
+        public ContainerContentsType(final Type<Item> itemType) {
+            super(itemType, 256);
+            this.itemType = itemType;
+        }
+
+        @Override
+        public void write(final Ops ops, final Item[] value) {
+            ops.writeList(list -> {
+                for (int i = 0; i < value.length; i++) {
+                    final Item item = value[i];
+                    final int slot = i;
+                    list.writeMap(map -> map
+                        .write("slot", Types.INT, slot)
+                        .write("item", itemType, item));
+                }
+            });
+        }
+    }
+}

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

@@ -22,11 +22,16 @@
  */
 package com.viaversion.viaversion.api.minecraft.item.data;
 
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
 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.ArrayUtil;
+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
@@ -45,5 +50,19 @@ public record CustomModelData1_21_4(float[] floats, boolean[] booleans, String[]
             Types.STRING_ARRAY.write(buffer, value.strings());
             Types.INT_ARRAY_PRIMITIVE.write(buffer, value.colors());
         }
+
+        @Override
+        public void write(final Ops ops, final CustomModelData1_21_4 value) {
+            ops.writeMap(map -> map
+                .writeOptional("floats", new ArrayType<>(Types.FLOAT), ArrayUtil.boxedArray(value.floats), new Float[0])
+                .writeOptional("flags", new ArrayType<>(Types.BOOLEAN), ArrayUtil.boxedArray(value.booleans), new Boolean[0])
+                .writeOptional("strings", Types.STRING_ARRAY, value.strings(), new String[0])
+                .writeOptional("colors", new ArrayType<>(Types.INT), ArrayUtil.boxedArray(value.colors), new Integer[0]));
+        }
     };
+
+    @Override
+    public CustomModelData1_21_4 copy() {
+        return new CustomModelData1_21_4(Copyable.copy(floats), Copyable.copy(booleans), Copyable.copy(strings), Copyable.copy(colors));
+    }
 }

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

@@ -22,22 +22,29 @@
  */
 package com.viaversion.viaversion.api.minecraft.item.data;
 
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.util.Key;
 import io.netty.buffer.ByteBuf;
 
-public record DamageResistant(String typesTagKey) {
+public record DamageResistant(Key typesTagKey) {
 
     public static final Type<DamageResistant> TYPE = new Type<>(DamageResistant.class) {
         @Override
         public DamageResistant read(final ByteBuf buffer) {
-            final String typesTagKey = Types.STRING.read(buffer);
+            final Key typesTagKey = Types.RESOURCE_LOCATION.read(buffer);
             return new DamageResistant(typesTagKey);
         }
 
         @Override
         public void write(final ByteBuf buffer, final DamageResistant value) {
-            Types.STRING.write(buffer, value.typesTagKey());
+            Types.RESOURCE_LOCATION.write(buffer, value.typesTagKey());
+        }
+
+        @Override
+        public void write(final Ops ops, final DamageResistant value) {
+            ops.writeMap(map -> map.write("types", Types.TAG_KEY, value.typesTagKey));
         }
     };
 }

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(Copyable.copy(deathEffects));
+    }
 }

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

@@ -22,12 +22,18 @@
  */
 package com.viaversion.viaversion.api.minecraft.item.data;
 
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
 import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.Types;
 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 +47,21 @@ 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);
+        }
+
+        @Override
+        public void write(final Ops ops, final DyedColor dyedColor) {
+            ops.write(Types.INT, dyedColor.rgb);
+        }
+    };
 }

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

@@ -20,26 +20,29 @@
  * 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;
+package com.viaversion.viaversion.api.minecraft.item.data;
 
-import com.viaversion.viaversion.api.minecraft.chunks.ChunkSection;
-import com.viaversion.viaversion.api.minecraft.entitydata.EntityData;
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
 import com.viaversion.viaversion.api.type.Type;
-import com.viaversion.viaversion.api.type.types.chunk.ChunkSectionType1_8;
-import com.viaversion.viaversion.api.type.types.entitydata.EntityDataListType;
-import com.viaversion.viaversion.api.type.types.entitydata.EntityDataType1_8;
-import java.util.List;
+import com.viaversion.viaversion.api.type.Types;
+import io.netty.buffer.ByteBuf;
 
-public final class Types1_8 {
+public record Enchantable(int value) {
 
-    /**
-     * Entity data type for 1.8
-     */
-    public static final Type<EntityData> ENTITY_DATA = new EntityDataType1_8();
-    /**
-     * Entity data list type for 1.8
-     */
-    public static final Type<List<EntityData>> ENTITY_DATA_LIST = new EntityDataListType(ENTITY_DATA);
+    public static final Type<Enchantable> TYPE = new Type<>(Enchantable.class) {
+        @Override
+        public Enchantable read(final ByteBuf buffer) {
+            return new Enchantable(Types.VAR_INT.readPrimitive(buffer));
+        }
 
-    public static final Type<ChunkSection> CHUNK_SECTION = new ChunkSectionType1_8();
+        @Override
+        public void write(final ByteBuf buffer, final Enchantable value) {
+            Types.VAR_INT.writePrimitive(buffer, value.value);
+        }
+
+        @Override
+        public void write(final Ops ops, final Enchantable enchantable) {
+            ops.writeMap(map -> map.write("value", Types.INT, enchantable.value));
+        }
+    };
 }

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

@@ -22,15 +22,22 @@
  */
 package com.viaversion.viaversion.api.minecraft.item.data;
 
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.util.Copyable;
+import com.viaversion.viaversion.util.Key;
 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 +61,39 @@ 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());
+            }
+        }
+
+        @Override
+        public void write(final Ops ops, final Enchantments value) {
+            ops.writeMap(map -> {
+                for (final Int2IntMap.Entry entry : value.enchantments.int2IntEntrySet()) {
+                    final Key key = ops.context().registryAccess().enchantment(entry.getIntKey());
+                    map.write(Types.RESOURCE_LOCATION, key, Types.VAR_INT, entry.getIntValue());
+                }
+            });
+        }
+    };
 
     public Enchantments(final boolean showInTooltip) {
         this(new Int2IntOpenHashMap(), showInTooltip);
@@ -78,4 +118,9 @@ 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/EnumTypes.java

@@ -0,0 +1,51 @@
+/*
+ * 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.types.EnumType;
+import com.viaversion.viaversion.api.type.types.EnumType.Fallback;
+import com.viaversion.viaversion.api.type.types.FakeEnumType;
+import com.viaversion.viaversion.api.type.types.RegistryValueType;
+import java.util.List;
+
+import static com.viaversion.viaversion.api.type.types.FakeEnumType.Entry.of;
+
+/**
+ * Enum types that aren't associated with any specific item data in this package.
+ */
+public final class EnumTypes {
+
+    public static final EnumType DYE_COLOR = new EnumType("white", "orange", "magenta", "light_blue", "yellow", "lime", "pink", "gray", "light_gray", "cyan", "purple", "blue", "brown", "green", "red", "black");
+    public static final EnumType RARITY = new EnumType("common", "uncommon", "rare", "epic");
+    public static final EnumType FOX_VARIANT = new EnumType("red", "snow");
+    public static final EnumType SALMON_VARIANT = new EnumType(Fallback.CLAMP, "small", "medium", "large");
+    public static final EnumType PARROT_VARIANT = new EnumType(Fallback.CLAMP, "red_blue", "blue", "green", "yellow_blue", "gray");
+    public static final EnumType MUSHROOM_COW_VARIANT = new EnumType(Fallback.CLAMP, "red", "brown");
+    public static final EnumType HORSE_VARIANT = new EnumType(Fallback.WRAP, "white", "creamy", "chestnut", "brown", "black", "gray", "dark_brown");
+    public static final EnumType LLAMA_VARIANT = new EnumType(Fallback.CLAMP, "creamy", "white", "brown", "gray");
+    public static final EnumType AXOLOTL_VARIANT = new EnumType("lucy", "wild", "gold", "cyan", "blue");
+    // Enums with non-ordinal ids
+    public static final FakeEnumType RABBIT_VARIANT = new FakeEnumType(List.of("brown", "white", "black", "white_splotched", "gold", "salt"), of(99, "evil"));
+    // Pretty much enums, but with a resource location
+    public static final RegistryValueType VILLAGER_TYPE = new RegistryValueType("desert", "jungle", "plains", "savanna", "snow", "swamp", "taiga");
+}

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

@@ -22,20 +22,33 @@
  */
 package com.viaversion.viaversion.api.minecraft.item.data;
 
+import com.viaversion.viaversion.api.connection.UserConnection;
 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.protocol.Protocol;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.util.Rewritable;
 import io.netty.buffer.ByteBuf;
-import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 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,
+                         boolean canBeSheared, Holder<SoundEvent> shearingSound) implements Rewritable {
 
-    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 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, final boolean equipOnInteract) {
+        this(equipmentSlot, soundEvent, model, cameraOverlay, allowedEntities, dispensable, swappable, damageOnHurt, equipOnInteract, false, Holder.of(0));
+    }
+
+    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 +74,71 @@ 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);
+        }
 
-    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);
+        @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 static final Type<Equippable> TYPE1_21_6 = 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();
+            final boolean canBeSheared = buffer.readBoolean();
+            final Holder<SoundEvent> shearingSound = Types.SOUND_EVENT.read(buffer);
+            return new Equippable(equipmentSlot, soundEvent, model, cameraOverlay, allowedEntities, dispensable, swappable, damageOnHurt, equipOnInteract, canBeSheared, shearingSound);
+        }
+
+        @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());
+            buffer.writeBoolean(value.canBeSheared());
+            Types.SOUND_EVENT.write(buffer, value.shearingSound());
+        }
+    };
+
+    @Override
+    public Equippable rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+        final Holder<SoundEvent> soundEvent = this.soundEvent.updateId(Rewritable.soundRewriteFunction(protocol, clientbound));
+        final Holder<SoundEvent> shearingSound = this.shearingSound.updateId(Rewritable.soundRewriteFunction(protocol, clientbound));
+        return soundEvent == this.soundEvent && shearingSound == this.shearingSound ? this : new Equippable(equipmentSlot, soundEvent, model, cameraOverlay, allowedEntities, dispensable, swappable, damageOnHurt, equipOnInteract, canBeSheared, shearingSound);
     }
 }

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

@@ -22,6 +22,7 @@
  */
 package com.viaversion.viaversion.api.minecraft.item.data;
 
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
 import com.viaversion.viaversion.api.type.Type;
 import io.netty.buffer.ByteBuf;
 import org.checkerframework.checker.nullness.qual.Nullable;
@@ -74,6 +75,13 @@ public abstract class Filterable<T> {
             optionalElementType.write(buffer, value.filtered());
         }
 
+        @Override
+        public void write(final Ops ops, final F value) {
+            ops.writeMap(map -> map
+                .write("raw", elementType, value.raw())
+                .writeOptional("filtered", elementType, value.filtered()));
+        }
+
         protected abstract F create(T raw, T filtered);
     }
 }

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

@@ -23,12 +23,16 @@
 package com.viaversion.viaversion.api.minecraft.item.data;
 
 import com.viaversion.nbt.tag.Tag;
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.protocol.Protocol;
 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 com.viaversion.viaversion.util.Rewritable;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
-public final class FilterableComponent extends Filterable<Tag> {
+public final class FilterableComponent extends Filterable<Tag> implements Copyable, Rewritable {
 
     public static final Type<FilterableComponent> TYPE = new FilterableType<>(Types.TAG, Types.OPTIONAL_TAG, FilterableComponent.class) {
         @Override
@@ -41,4 +45,21 @@ public final class FilterableComponent extends Filterable<Tag> {
     public FilterableComponent(final Tag raw, @Nullable final Tag filtered) {
         super(raw, filtered);
     }
+
+    @Override
+    public FilterableComponent rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+        if (protocol.getComponentRewriter() == null) {
+            return this;
+        }
+
+        final FilterableComponent copy = copy();
+        protocol.getComponentRewriter().processTag(connection, copy.raw());
+        protocol.getComponentRewriter().processTag(connection, copy.filtered());
+        return copy;
+    }
+
+    @Override
+    public FilterableComponent copy() {
+        return new FilterableComponent(raw().copy(), filtered() != null ? filtered().copy() : null);
+    }
 }

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

@@ -22,12 +22,18 @@
  */
 package com.viaversion.viaversion.api.minecraft.item.data;
 
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
 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.ArrayUtil;
+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 String[] SHAPES = {"small_ball", "large_ball", "star", "creeper", "burst"};
+
     public static final Type<FireworkExplosion> TYPE = new Type<>(FireworkExplosion.class) {
         @Override
         public FireworkExplosion read(final ByteBuf buffer) {
@@ -47,7 +53,21 @@ public record FireworkExplosion(int shape, int[] colors, int[] fadeColors, boole
             buffer.writeBoolean(value.hasTrail);
             buffer.writeBoolean(value.hasTwinkle);
         }
+
+        @Override
+        public void write(final Ops ops, final FireworkExplosion value) {
+            ops.writeMap(map -> map
+                .write("shape", Types.STRING, SHAPES[value.shape])
+                .writeOptional("colors", new ArrayType<>(Types.INT), ArrayUtil.boxedArray(value.colors), new Integer[0])
+                .writeOptional("fade_colors", new ArrayType<>(Types.INT), ArrayUtil.boxedArray(value.fadeColors), new Integer[0])
+                .writeOptional("has_trail", Types.BOOLEAN, value.hasTrail, false)
+                .writeOptional("has_twinkle", Types.BOOLEAN, value.hasTwinkle, false));
+        }
     };
     public static final Type<FireworkExplosion[]> ARRAY_TYPE = new ArrayType<>(TYPE);
 
+    @Override
+    public FireworkExplosion copy() {
+        return new FireworkExplosion(shape, Copyable.copy(colors), Copyable.copy(fadeColors), hasTrail, hasTwinkle);
+    }
 }

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

@@ -22,11 +22,13 @@
  */
 package com.viaversion.viaversion.api.minecraft.item.data;
 
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
 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
@@ -41,6 +43,17 @@ public record Fireworks(int flightDuration, FireworkExplosion[] explosions) {
             Types.VAR_INT.writePrimitive(buffer, value.flightDuration);
             FireworkExplosion.ARRAY_TYPE.write(buffer, value.explosions);
         }
+
+        @Override
+        public void write(final Ops ops, final Fireworks value) {
+            ops.writeMap(map -> map
+                .writeOptional("flight_duration", Types.UNSIGNED_BYTE, (short) value.flightDuration, (short) 0)
+                .writeOptional("explosions", FireworkExplosion.ARRAY_TYPE, value.explosions, new FireworkExplosion[0]));
+        }
     };
 
+    @Override
+    public Fireworks copy() {
+        return new Fireworks(flightDuration, Copyable.copy(explosions));
+    }
 }

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

@@ -26,12 +26,13 @@ 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.ArrayType;
-import com.viaversion.viaversion.api.type.types.version.Types1_21;
+import com.viaversion.viaversion.api.type.types.version.VersionedTypes;
+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
@@ -60,7 +61,7 @@ public record FoodProperties1_20_5(int nutrition, float saturationModifier, bool
             final float saturationModifier = buffer.readFloat();
             final boolean canAlwaysEat = buffer.readBoolean();
             final float eatSeconds = buffer.readFloat();
-            final Item usingConvertsTo = Types1_21.OPTIONAL_ITEM.read(buffer);
+            final Item usingConvertsTo = VersionedTypes.V1_21.optionalItem.read(buffer);
             final FoodEffect[] possibleEffects = FoodEffect.ARRAY_TYPE.read(buffer);
             return new FoodProperties1_20_5(nutrition, saturationModifier, canAlwaysEat, eatSeconds, usingConvertsTo, possibleEffects);
         }
@@ -71,11 +72,16 @@ public record FoodProperties1_20_5(int nutrition, float saturationModifier, bool
             buffer.writeFloat(value.saturationModifier);
             buffer.writeBoolean(value.canAlwaysEat);
             buffer.writeFloat(value.eatSeconds);
-            Types1_21.OPTIONAL_ITEM.write(buffer, value.usingConvertsTo);
+            VersionedTypes.V1_21.optionalItem.write(buffer, value.usingConvertsTo);
             FoodEffect.ARRAY_TYPE.write(buffer, value.possibleEffects);
         }
     };
 
+    @Override
+    public FoodProperties1_20_5 copy() {
+        return new FoodProperties1_20_5(nutrition, saturationModifier, canAlwaysEat, eatSeconds, usingConvertsTo == null ? null : usingConvertsTo.copy(), Copyable.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/FoodProperties1_21_2.java

@@ -22,6 +22,7 @@
  */
 package com.viaversion.viaversion.api.minecraft.item.data;
 
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
 import io.netty.buffer.ByteBuf;
@@ -43,5 +44,13 @@ public record FoodProperties1_21_2(int nutrition, float saturationModifier, bool
             buffer.writeFloat(value.saturationModifier);
             buffer.writeBoolean(value.canAlwaysEat);
         }
+
+        @Override
+        public void write(final Ops ops, final FoodProperties1_21_2 value) {
+            ops.writeMap(map -> map
+                .write("nutrition", Types.VAR_INT, value.nutrition)
+                .write("saturation", Types.FLOAT, value.saturationModifier)
+                .writeOptional("can_always_eat", Types.BOOLEAN, value.canAlwaysEat, false));
+        }
     };
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/Instrument1_20_5.java

@@ -22,14 +22,16 @@
  */
 package com.viaversion.viaversion.api.minecraft.item.data;
 
+import com.viaversion.viaversion.api.connection.UserConnection;
 import com.viaversion.viaversion.api.minecraft.Holder;
 import com.viaversion.viaversion.api.minecraft.SoundEvent;
+import com.viaversion.viaversion.api.protocol.Protocol;
 import com.viaversion.viaversion.api.type.Types;
 import com.viaversion.viaversion.api.type.types.misc.HolderType;
+import com.viaversion.viaversion.util.Rewritable;
 import io.netty.buffer.ByteBuf;
-import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 
-public record Instrument1_20_5(Holder<SoundEvent> soundEvent, int useDuration, float range) {
+public record Instrument1_20_5(Holder<SoundEvent> soundEvent, int useDuration, float range) implements Rewritable {
 
     public static final HolderType<Instrument1_20_5> TYPE = new HolderType<>() {
         @Override
@@ -48,8 +50,9 @@ public record Instrument1_20_5(Holder<SoundEvent> soundEvent, int useDuration, f
         }
     };
 
-    public Instrument1_20_5 rewrite(final Int2IntFunction soundIdRewriteFunction) {
-        final Holder<SoundEvent> soundEvent = this.soundEvent.updateId(soundIdRewriteFunction);
+    @Override
+    public Instrument1_20_5 rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+        final Holder<SoundEvent> soundEvent = this.soundEvent.updateId(Rewritable.soundRewriteFunction(protocol, clientbound));
         return soundEvent == this.soundEvent ? this : new Instrument1_20_5(soundEvent, useDuration, range);
     }
 }

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

@@ -23,14 +23,19 @@
 package com.viaversion.viaversion.api.minecraft.item.data;
 
 import com.viaversion.nbt.tag.Tag;
+import com.viaversion.viaversion.api.connection.UserConnection;
 import com.viaversion.viaversion.api.minecraft.Holder;
 import com.viaversion.viaversion.api.minecraft.SoundEvent;
+import com.viaversion.viaversion.api.protocol.Protocol;
 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 com.viaversion.viaversion.util.Rewritable;
 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, Rewritable {
 
     public static final HolderType<Instrument1_21_2> TYPE = new HolderType<>() {
         @Override
@@ -50,9 +55,16 @@ 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);
+    @Override
+    public Instrument1_21_2 rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+        final Holder<SoundEvent> soundEvent = this.soundEvent.updateId(Rewritable.soundRewriteFunction(protocol, clientbound));
         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

@@ -23,56 +23,72 @@
 package com.viaversion.viaversion.api.minecraft.item.data;
 
 import com.viaversion.nbt.tag.Tag;
+import com.viaversion.viaversion.api.connection.UserConnection;
+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.protocol.Protocol;
 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 com.viaversion.viaversion.util.Rewritable;
 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) implements Rewritable {
 
     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);
+        }
 
-    public JukeboxPlayable rewrite(final Int2IntFunction soundIdRewriteFunction) {
-        if (song.isRight()) {
+        @Override
+        public void write(final ByteBuf buffer, final JukeboxPlayable value) {
+            EitherHolderType.write(buffer, value.song, JukeboxSong.TYPE);
+        }
+    };
+
+    @Override
+    public JukeboxPlayable rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+        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;
         }
 
-        final JukeboxSong rewrittenSong = songHolder.value().rewrite(soundIdRewriteFunction);
+        final JukeboxSong rewrittenSong = songHolder.value().rewrite(connection, protocol, clientbound);
         return rewrittenSong == songHolder.value() ? this : new JukeboxPlayable(Holder.of(rewrittenSong), showInTooltip);
     }
 
     public record JukeboxSong(Holder<SoundEvent> soundEvent, Tag description,
-                              float lengthInSeconds, int comparatorOutput) {
+                              float lengthInSeconds, int comparatorOutput) implements Rewritable {
 
         public static final HolderType<JukeboxSong> TYPE = new HolderType<>() {
             @Override
@@ -93,8 +109,9 @@ public record JukeboxPlayable(Either<Holder<JukeboxSong>, String> song, boolean
             }
         };
 
-        public JukeboxSong rewrite(final Int2IntFunction soundIdRewriteFunction) {
-            final Holder<SoundEvent> soundEvent = this.soundEvent.updateId(soundIdRewriteFunction);
+        @Override
+        public JukeboxSong rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+            final Holder<SoundEvent> soundEvent = this.soundEvent.updateId(Rewritable.soundRewriteFunction(protocol, clientbound));
             return soundEvent == this.soundEvent ? this : new JukeboxSong(soundEvent, description, lengthInSeconds, comparatorOutput);
         }
     }

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

@@ -23,6 +23,7 @@
 package com.viaversion.viaversion.api.minecraft.item.data;
 
 import com.viaversion.viaversion.api.minecraft.GlobalBlockPosition;
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
 import io.netty.buffer.ByteBuf;
@@ -43,6 +44,12 @@ public record LodestoneTracker(@Nullable GlobalBlockPosition position, boolean t
             Types.OPTIONAL_GLOBAL_POSITION.write(buffer, value.position);
             buffer.writeBoolean(value.tracked);
         }
-    };
 
+        @Override
+        public void write(final Ops ops, final LodestoneTracker value) {
+            ops.writeMap(map -> map
+                .writeOptional("target", Types.GLOBAL_POSITION, value.position)
+                .writeOptional("tracked", Types.BOOLEAN, value.tracked, true));
+        }
+    };
 }

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

@@ -22,12 +22,15 @@
  */
 package com.viaversion.viaversion.api.minecraft.item.data;
 
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.protocol.Protocol;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.util.Copyable;
+import com.viaversion.viaversion.util.Rewritable;
 import io.netty.buffer.ByteBuf;
-import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 
-public final class PotDecorations {
+public final class PotDecorations implements Copyable, Rewritable {
 
     public static final Type<PotDecorations> TYPE = new Type<>(PotDecorations.class) {
         @Override
@@ -75,11 +78,17 @@ public final class PotDecorations {
         return index < 0 || index >= itemIds.length ? -1 : itemIds[index];
     }
 
-    public PotDecorations rewrite(final Int2IntFunction idRewriteFunction) {
+    @Override
+    public PotDecorations rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
         final int[] newItems = new int[itemIds.length];
         for (int i = 0; i < itemIds.length; i++) {
-            newItems[i] = idRewriteFunction.applyAsInt(itemIds[i]);
+            newItems[i] = Rewritable.rewriteItem(protocol, clientbound, itemIds[i]);
         }
         return new PotDecorations(newItems);
     }
+
+    @Override
+    public PotDecorations copy() {
+        return new PotDecorations(Copyable.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, Copyable.copy(customEffects), customName);
+    }
 }

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

@@ -0,0 +1,59 @@
+/*
+ * 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.connection.UserConnection;
+import com.viaversion.viaversion.api.minecraft.EitherHolder;
+import com.viaversion.viaversion.api.minecraft.Holder;
+import com.viaversion.viaversion.api.protocol.Protocol;
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.types.misc.EitherHolderType;
+import com.viaversion.viaversion.util.Rewritable;
+import io.netty.buffer.ByteBuf;
+
+public record ProvidesTrimMaterial(EitherHolder<ArmorTrimMaterial> material) implements Rewritable {
+
+    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);
+        }
+    };
+
+    @Override
+    public ProvidesTrimMaterial rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+        if (material.hasKey() || material.holder().hasId()) {
+            return this;
+        }
+
+        final ArmorTrimMaterial trimMaterial = material.holder().value();
+        return new ProvidesTrimMaterial(EitherHolder.of(Holder.of(trimMaterial.rewrite(connection, protocol, clientbound))));
+    }
+}

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

@@ -22,20 +22,27 @@
  */
 package com.viaversion.viaversion.api.minecraft.item.data;
 
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.protocol.Protocol;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.util.Rewritable;
 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) implements Rewritable {
 
-    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 +52,31 @@ 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);
+        }
 
-    public ToolProperties rewrite(final Int2IntFunction blockIdRewriter) {
+        @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());
+        }
+    };
+
+    @Override
+    public ToolProperties rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
         final ToolRule[] rules = new ToolRule[this.rules.length];
         for (int i = 0; i < rules.length; i++) {
-            rules[i] = this.rules[i].rewrite(blockIdRewriter);
+            rules[i] = this.rules[i].rewrite(connection, protocol, clientbound);
         }
-        return new ToolProperties(rules, defaultMiningSpeed, damagePerBlock);
+        return new ToolProperties(rules, defaultMiningSpeed, damagePerBlock, canDestroyBlocksInCreative);
     }
 }

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

@@ -22,15 +22,18 @@
  */
 package com.viaversion.viaversion.api.minecraft.item.data;
 
+import com.viaversion.viaversion.api.connection.UserConnection;
 import com.viaversion.viaversion.api.minecraft.HolderSet;
+import com.viaversion.viaversion.api.protocol.Protocol;
 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.Rewritable;
 import io.netty.buffer.ByteBuf;
-import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
-public record ToolRule(HolderSet blocks, @Nullable Float speed, @Nullable Boolean correctForDrops) {
+public record ToolRule(HolderSet blocks, @Nullable Float speed,
+                       @Nullable Boolean correctForDrops) implements Rewritable {
 
     public static final Type<ToolRule> TYPE = new Type<>(ToolRule.class) {
         @Override
@@ -50,7 +53,8 @@ public record ToolRule(HolderSet blocks, @Nullable Float speed, @Nullable Boolea
     };
     public static final Type<ToolRule[]> ARRAY_TYPE = new ArrayType<>(TYPE);
 
-    public ToolRule rewrite(final Int2IntFunction blockIdRewriter) {
-        return blocks.hasIds() ? new ToolRule(blocks.rewrite(blockIdRewriter), speed, correctForDrops) : this;
+    @Override
+    public ToolRule rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+        return blocks.hasIds() ? new ToolRule(blocks.rewrite(Rewritable.blockRewriteFunction(protocol, clientbound)), speed, correctForDrops) : this;
     }
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/TooltipDisplay.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.item.data;
+
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
+import com.viaversion.viaversion.api.protocol.Protocol;
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.util.Key;
+import com.viaversion.viaversion.util.Rewritable;
+import io.netty.buffer.ByteBuf;
+import it.unimi.dsi.fastutil.ints.IntLinkedOpenHashSet;
+import it.unimi.dsi.fastutil.ints.IntSortedSet;
+
+public record TooltipDisplay(boolean hideTooltip,
+                             IntSortedSet hiddenComponents) implements Rewritable { // 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);
+            }
+        }
+
+        @Override
+        public void write(final Ops ops, final TooltipDisplay value) {
+            final Key[] hiddenComponents = value.hiddenComponents.intStream().mapToObj(id -> ops.context().registryAccess().dataComponentType(id)).toArray(Key[]::new);
+            ops.writeMap(map -> map
+                .writeOptional("hide_tooltip", Types.BOOLEAN, value.hideTooltip, false)
+                .writeOptional("hidden_components", Types.RESOURCE_LOCATION_ARRAY, hiddenComponents, new Key[0]));
+        }
+    };
+
+    @Override
+    public TooltipDisplay rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+        if (hiddenComponents.isEmpty()) {
+            return this;
+        }
+
+        final IntSortedSet newHiddenComponents = new IntLinkedOpenHashSet();
+        for (final int hiddenComponent : hiddenComponents) {
+            newHiddenComponents.add(Rewritable.rewriteDataComponentType(protocol, clientbound, hiddenComponent));
+        }
+        return new TooltipDisplay(hideTooltip, newHiddenComponents);
+    }
+}