5.5.1 Release

Technically unused in VV for now, but may also replace some in-code sound mappings later

.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:
@@ -11,13 +11,13 @@ jobs:
 
     steps:
     - name: Checkout Repository
-      uses: actions/checkout@v4
+      uses: actions/checkout@v5
       with:
         persist-credentials: false
     - name: Set up Gradle
-      uses: gradle/actions/setup-gradle@v4
+      uses: gradle/actions/setup-gradle@v5
     - name: Set up JDK 17
-      uses: actions/setup-java@v4
+      uses: actions/setup-java@v5
       with:
         distribution: 'temurin'
         java-version: 17
@@ -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:
@@ -11,19 +12,26 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       - name: Checkout Repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           persist-credentials: false
       - name: Set up Gradle
-        uses: gradle/actions/setup-gradle@v4
+        uses: gradle/actions/setup-gradle@v5
       - name: Set up JDK 17
-        uses: actions/setup-java@v4
+        uses: actions/setup-java@v5
         with:
           distribution: 'temurin'
           java-version: 17
           check-latest: true
-      - name: Publish
+      - name: Build
+        run: ./gradlew build
+      - name: Publish to Hangar
         env:
           HANGAR_TOKEN: ${{ secrets.HANGAR_TOKEN }}
+        run: ./gradlew publishAllPublicationsToHangar --stacktrace
+        continue-on-error: true
+      - name: Publish to Modrinth
+        env:
           MODRINTH_TOKEN: ${{ secrets.MODRINTH_TOKEN }}
-        run: ./gradlew build modrinth publishAllPublicationsToHangar --stacktrace
+        run: ./gradlew modrinth --stacktrace
+        continue-on-error: true

.github/workflows/update-gradle-wrapper.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       - name: Checkout Repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           persist-credentials: false
       - name: Update Gradle Wrapper

.gitignore

@@ -1,115 +1,36 @@
-### Java files ###
-*.class
+# Gradle
 
-# Package Files
-#*.jar
-*.war
-*.ear
+.gradle/
+build/
+out/
+classes/
+.kotlin/
 
-# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
-hs_err_pid*
+# Eclipse
 
+*.launch
 
+# Idea
 
-### Intellij ###
-# Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm
-# Ignore project files
-*.iml
-
-# Ignore IDEA directory
-.idea/*
+.idea/
 !.idea/copyright/*
 !.idea/scopes/*
-
-# Include the project's dictionary
-!.idea/dictionaries/
-!.idea/dictionaries/*
-
-# File-based project format:
+*.iml
 *.ipr
 *.iws
 
-### Plugin-specific files: ###
-# IntelliJ
-/out/
+# VSCode
 
-# mpeltonen/sbt-idea plugin
-.idea_modules/
-
-# JIRA plugin
-atlassian-ide-plugin.xml
-
-# Crashlytics plugin (for Android Studio and IntelliJ)
-com_crashlytics_export_strings.xml
-crashlytics.properties
-crashlytics-build.properties
-
-
-
-### Eclipse ###
-*.pydevproject
-.metadata
-.gradle
-bin/
-tmp/
-*.tmp
-*.bak
-*.swp
-*~.nib
-local.properties
 .settings/
-.loadpath
-
-# Eclipse Core
+.vscode/
+bin/
+.classpath
 .project
 
-# External tool builders
-.externalToolBuilders/
+# macOS
 
-# Locally stored "Eclipse launch configurations"
-*.launch
-
-# CDT-specific
-.cproject
-
-# JDT-specific (Eclipse Java Development Tools)
-.classpath
-
-# PDT-specific
-.buildpath
-
-# sbteclipse plugin
-.target
-
-# TeXlipse plugin
-.texlipse
-
-
-
-### Maven ###
-target/
-pom.xml.tag
-pom.xml.releaseBackup
-pom.xml.versionsBackup
-pom.xml.next
-release.properties
-dependency-reduced-pom.xml
-buildNumber.properties
-
-
-
-### NetBeans ###
-nbproject/private/
-build/
-nbbuild/
-dist/
-nbdist/
-nbactions.xml
-nb-configuration.xml
-.nb-gradle/
-
-### MacOS ###
 .DS_Store
 
-### Run Folder (ViaProxy) ###
-common/run/
+# Misc
+
+run/

README.md

@@ -8,7 +8,7 @@
 it works on any platform you can think of.**
 
 The base ViaVersion jar runs on Paper and Velocity. We also have projects integrating ViaVersion to run
-on Fabric, Forge, Bungee, Sponge, or as a standalone proxy to join from basically any client version on
+on Fabric, Forge, Sponge, or as a standalone proxy to join from basically any client version on
 any server version from the past decade. **See [HERE](https://viaversion.com) for an overview of the different Via\* projects.**
 
 Note that ViaVersion will be able to **run best on either Paper servers or through [ViaFabricPlus](https://github.com/ViaVersion/ViaFabricPlus?tab=readme-ov-file#viafabricplus)** due to having
@@ -16,7 +16,7 @@ direct access to client/server state and more extensive API.
 
 Supported Versions:
 
-![Table (https://i.imgur.com/zrQTcf0.png)](https://i.imgur.com/zrQTcf0.png)
+![Table (https://ci.viaversion.com/userContent/images/T.png)](https://ci.viaversion.com/userContent/images/T.png)
 
 **User Docs:** https://docs.viaversion.com
 
@@ -87,12 +87,10 @@ of the `build/libs` directory.
 
 You need JDK 17 or newer to build ViaVersion.
 
-
 Mapping Files
 --------------
 Mapping files are generated and managed in our [Mappings repository](https://github.com/ViaVersion/Mappings). The generated mapping output is stored [here](./common/src/main/resources/assets/viaversion).
 
-
 Resources
 --------
 

SECURITY.md

@@ -0,0 +1,10 @@
+# Security Policy
+
+## Reporting a Vulnerability
+
+If you discover a **security vulnerability**, please **do not** open a public issue. Instead, use one of the following **confidential contact methods**:
+
+* **Email:** [security@viaversion.com](mailto:security@viaversion.com)
+* **Discord:** Join our [Discord server](https://discord.gg/viaversion) and visit the [#exploit-report](https://discord.com/channels/316206679014244363/1388847764137316485) channel for further instructions.
+
+If your issue is **not security-related** (e.g., bug reports, feature requests, or usage questions), please use the [GitHub Issues page](https://github.com/ViaVersion/ViaVersion/issues) or contact us via the [Discord server](https://discord.gg/viaversion).

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

@@ -123,7 +123,7 @@ public interface ViaAPI<T> {
     boolean isInjected(UUID uuid);
 
     /**
-     * Returns whether Via injected into this player connection. Note that this method may not work on
+     * Returns the injected UserConnection if present. 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

api/src/main/java/com/viaversion/viaversion/api/configuration/RateLimitConfig.java

@@ -0,0 +1,27 @@
+/*
+ * 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.configuration;
+
+public record RateLimitConfig(boolean enabled, int maxRate, String maxRateKickMessage, int warningRate, int maxWarnings,
+                              long trackingPeriodNanos, String warningKickMessage, String ratePlaceholder) {
+}

api/src/main/java/com/viaversion/viaversion/api/configuration/ViaVersionConfig.java

@@ -147,6 +147,7 @@ public interface ViaVersionConfig extends Config {
      *
      * @return The number of packets a client can send per second.
      */
+    @Deprecated(forRemoval = true)
     int getMaxPPS();
 
     /**
@@ -154,6 +155,7 @@ public interface ViaVersionConfig extends Config {
      *
      * @return Kick message, with colour codes using '&'
      */
+    @Deprecated(forRemoval = true)
     String getMaxPPSKickMessage();
 
     /**
@@ -161,6 +163,7 @@ public interface ViaVersionConfig extends Config {
      *
      * @return Time in seconds that should be tracked for warnings
      */
+    @Deprecated(forRemoval = true)
     int getTrackingPeriod();
 
     /**
@@ -168,6 +171,7 @@ public interface ViaVersionConfig extends Config {
      *
      * @return The number of packets per second to count as a warning.
      */
+    @Deprecated(forRemoval = true)
     int getWarningPPS();
 
     /**
@@ -175,6 +179,7 @@ public interface ViaVersionConfig extends Config {
      *
      * @return The number of packets a client can send per second.
      */
+    @Deprecated(forRemoval = true)
     int getMaxWarnings();
 
     /**
@@ -182,8 +187,13 @@ public interface ViaVersionConfig extends Config {
      *
      * @return Kick message, with colour codes using '&'
      */
+    @Deprecated(forRemoval = true)
     String getMaxWarningsKickMessage();
 
+    RateLimitConfig getPacketTrackerConfig();
+
+    RateLimitConfig getPacketSizeTrackerConfig();
+
     /**
      * Send supported versions in the status response packet
      *
@@ -233,13 +243,6 @@ public interface ViaVersionConfig extends Config {
      */
     boolean isChunkBorderFix();
 
-    /**
-     * Should we fix nbt array's in json chat messages for 1.12 clients
-     *
-     * @return true if enabled
-     */
-    boolean is1_12NBTArrayFix();
-
     /**
      * Should we make team colours based on the last colour in team prefix
      *
@@ -270,6 +273,8 @@ public interface ViaVersionConfig extends Config {
      */
     String getBlockedDisconnectMsg();
 
+    boolean logBlockedJoins();
+
     /**
      * Get the message sent to players being kicked on reload.
      * Players are kicked to stop the server crashing
@@ -285,6 +290,13 @@ 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)
      *
@@ -478,4 +490,12 @@ public interface ViaVersionConfig extends Config {
      * @return true if enabled
      */
     boolean fix1_21PlacementRotation();
+
+    /**
+     * If enabled, cancel swing packets sent while having an inventory opened on 1.15.2 and below servers.
+     * This can cause false positives with anti-cheat plugins.
+     *
+     * @return true if enabled
+     */
+    boolean cancelSwingInInventory();
 }

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

@@ -30,15 +30,6 @@ package com.viaversion.viaversion.api.connection;
  */
 public interface StorableObject {
 
-    /**
-     * Returns whether the object should be uncached on a server switch.
-     *
-     * @return whether the object should be uncached on a server switch
-     */
-    default boolean clearOnServerSwitch() {
-        return true;
-    }
-
     default void onRemove() {
     }
 }

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.
      *
@@ -121,17 +139,7 @@ public interface UserConnection {
     /**
      * Clear stored objects, entity trackers and client worlds.
      */
-    default void clearStoredObjects() {
-        clearStoredObjects(false);
-    }
-
-    /**
-     * Clear stored objects, entity trackers and client worlds.
-     * If cleared for a proxy server switch, some stored objects and tracker data will be retained.
-     *
-     * @param isServerSwitch whether the clear is due to a server switch
-     */
-    void clearStoredObjects(boolean isServerSwitch);
+    void clearStoredObjects();
 
     /**
      * Sends a raw packet to the connection on the current thread.
@@ -186,9 +194,15 @@ public interface UserConnection {
     /**
      * Monitors serverbound packets and returns whether a packet can/should be processed.
      *
+     * @param bytes the number of bytes in the packet
      * @return false if this packet should be cancelled
      */
-    boolean checkServerboundPacket();
+    boolean checkServerboundPacket(int bytes);
+
+    @Deprecated(forRemoval = true)
+    default boolean checkServerboundPacket() {
+        return checkServerboundPacket(0);
+    }
 
     /**
      * Monitors clientbound packets and returns whether a packet can/should be processed.
@@ -201,6 +215,11 @@ public interface UserConnection {
      * @see #checkClientboundPacket()
      * @see #checkServerboundPacket()
      */
+    default boolean checkIncomingPacket(final int bytes) {
+        return isClientSide() ? checkClientboundPacket() : checkServerboundPacket(bytes);
+    }
+
+    @Deprecated(forRemoval = true)
     default boolean checkIncomingPacket() {
         return isClientSide() ? checkClientboundPacket() : checkServerboundPacket();
     }

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

@@ -24,6 +24,7 @@ package com.viaversion.viaversion.api.data;
 
 import com.viaversion.viaversion.api.minecraft.RegistryType;
 import com.viaversion.viaversion.api.minecraft.TagData;
+import it.unimi.dsi.fastutil.ints.IntSet;
 import java.util.List;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
@@ -140,12 +141,14 @@ public interface MappingData {
 
     @Nullable Mappings getBlockMappings();
 
-    @Nullable Mappings getBlockEntityMappings();
+    @Nullable FullMappings getFullBlockMappings();
 
     @Nullable Mappings getBlockStateMappings();
 
     @Nullable Mappings getSoundMappings();
 
+    @Nullable FullMappings getFullSoundMappings();
+
     @Nullable Mappings getStatisticsMappings();
 
     @Nullable Mappings getMenuMappings();
@@ -154,6 +157,8 @@ public interface MappingData {
 
     @Nullable Mappings getPaintingMappings();
 
+    @Nullable FullMappings getBlockEntityMappings();
+
     @Nullable FullMappings getAttributeMappings();
 
     @Nullable FullMappings getEntityMappings();
@@ -163,4 +168,26 @@ public interface MappingData {
     @Nullable FullMappings getRecipeSerializerMappings();
 
     @Nullable FullMappings getDataComponentSerializerMappings();
+
+    default @Nullable FullMappings getFullMappings(final MappingType mappingType) {
+        return switch (mappingType) {
+            case ITEM -> getFullItemMappings();
+            case SOUND -> getFullSoundMappings();
+            case ENTITY -> getEntityMappings();
+        };
+    }
+
+    /**
+     * Set of block (not block state) ids that had their base type or properties changed.
+     *
+     * @return set of changed block ids, or null if not tracked/none are present
+     */
+    @Nullable IntSet changedBlocks();
+
+    /**
+     * Type of mappings. Currently only relevant for ops writing of generic holder classes and expanded when needed.
+     */
+    enum MappingType {
+        ITEM, SOUND, ENTITY
+    }
 }

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

@@ -28,6 +28,8 @@ import com.viaversion.nbt.tag.Tag;
 import com.viaversion.viaversion.api.Via;
 import com.viaversion.viaversion.api.minecraft.RegistryType;
 import com.viaversion.viaversion.api.minecraft.TagData;
+import it.unimi.dsi.fastutil.ints.IntOpenHashSet;
+import it.unimi.dsi.fastutil.ints.IntSet;
 import java.util.ArrayList;
 import java.util.EnumMap;
 import java.util.List;
@@ -44,17 +46,21 @@ public class MappingDataBase implements MappingData {
     protected FullMappings recipeSerializerMappings;
     protected FullMappings itemDataSerializerMappings;
     protected FullMappings attributeMappings;
+    protected FullMappings blockEntityMappings;
     protected ParticleMappings particleMappings;
     protected BiMappings itemMappings;
     protected BiMappings blockMappings;
     protected Mappings blockStateMappings;
-    protected Mappings blockEntityMappings;
     protected Mappings soundMappings;
     protected Mappings statisticsMappings;
     protected Mappings enchantmentMappings;
     protected Mappings paintingMappings;
     protected Mappings menuMappings;
     protected Map<RegistryType, List<TagData>> tags;
+    /**
+     * Set of block ids that have had type or property changes.
+     */
+    protected IntSet changedBlocks;
 
     public MappingDataBase(final String unmappedVersion, final String mappedVersion) {
         this.unmappedVersion = unmappedVersion;
@@ -68,10 +74,7 @@ public class MappingDataBase implements MappingData {
         }
 
         final CompoundTag data = readMappingsFile("mappings-" + unmappedVersion + "to" + mappedVersion + ".nbt");
-        blockMappings = loadBiMappings(data, "blocks");
         blockStateMappings = loadMappings(data, "blockstates");
-        blockEntityMappings = loadMappings(data, "blockentities");
-        soundMappings = loadMappings(data, "sounds");
         statisticsMappings = loadMappings(data, "statistics");
         menuMappings = loadMappings(data, "menus");
         enchantmentMappings = loadMappings(data, "enchantments");
@@ -80,12 +83,16 @@ public class MappingDataBase implements MappingData {
         final CompoundTag unmappedIdentifierData = readUnmappedIdentifiersFile("identifiers-" + unmappedVersion + ".nbt");
         final CompoundTag mappedIdentifierData = readMappedIdentifiersFile("identifiers-" + mappedVersion + ".nbt");
         if (unmappedIdentifierData != null && mappedIdentifierData != null) {
-            itemMappings = loadFullMappings(data, unmappedIdentifierData, mappedIdentifierData, "items");
+            itemMappings = loadFullOrBiMappings(data, unmappedIdentifierData, mappedIdentifierData, "items");
+            blockMappings = loadFullOrBiMappings(data, unmappedIdentifierData, mappedIdentifierData, "blocks");
+            soundMappings = loadFullOrBiMappings(data, unmappedIdentifierData, mappedIdentifierData, "sounds");
+
             entityMappings = loadFullMappings(data, unmappedIdentifierData, mappedIdentifierData, "entities");
             argumentTypeMappings = loadFullMappings(data, unmappedIdentifierData, mappedIdentifierData, "argumenttypes");
             recipeSerializerMappings = loadFullMappings(data, unmappedIdentifierData, mappedIdentifierData, "recipe_serializers");
             itemDataSerializerMappings = loadFullMappings(data, unmappedIdentifierData, mappedIdentifierData, "data_component_type");
             attributeMappings = loadFullMappings(data, unmappedIdentifierData, mappedIdentifierData, "attributes");
+            blockEntityMappings = loadFullMappings(data, unmappedIdentifierData, mappedIdentifierData, "blockentities");
 
             final List<String> unmappedParticles = identifiersFromGlobalIds(unmappedIdentifierData, "particles");
             final List<String> mappedParticles = identifiersFromGlobalIds(mappedIdentifierData, "particles");
@@ -99,6 +106,8 @@ public class MappingDataBase implements MappingData {
         } else {
             // Might not have identifiers in older versions
             itemMappings = loadBiMappings(data, "items");
+            blockMappings = loadBiMappings(data, "blocks");
+            soundMappings = loadMappings(data, "sounds");
         }
 
         final CompoundTag tagsTag = data.getCompoundTag("tags");
@@ -109,6 +118,11 @@ public class MappingDataBase implements MappingData {
             loadTags(RegistryType.ENTITY, tagsTag);
         }
 
+        final IntArrayTag changedBlocks = data.getIntArrayTag("changed_blocks");
+        if (changedBlocks != null) {
+            this.changedBlocks = new IntOpenHashSet(changedBlocks.getValue());
+        }
+
         loadExtras(data);
     }
 
@@ -132,6 +146,11 @@ public class MappingDataBase implements MappingData {
         return MappingDataLoader.INSTANCE.loadMappings(data, key);
     }
 
+    protected @Nullable BiMappings loadFullOrBiMappings(final CompoundTag data, final CompoundTag unmappedIdentifiersTag, final CompoundTag mappedIdentifiersTag, final String key) {
+        final FullMappings mappings = loadFullMappings(data, unmappedIdentifiersTag, mappedIdentifiersTag, key);
+        return mappings != null ? mappings : loadBiMappings(data, key);
+    }
+
     protected @Nullable FullMappings loadFullMappings(final CompoundTag data, final CompoundTag unmappedIdentifiersTag, final CompoundTag mappedIdentifiersTag, final String key) {
         if (!unmappedIdentifiersTag.contains(key) || !mappedIdentifiersTag.contains(key)) {
             return null;
@@ -208,8 +227,8 @@ public class MappingDataBase implements MappingData {
     }
 
     @Override
-    public int getOldSoundId(final int i) {
-        return soundMappings.getNewIdOrDefault(i, 0);
+    public int getOldSoundId(final int id) {
+        return soundMappings.inverse().getNewIdOrDefault(id, 0);
     }
 
     @Override
@@ -224,8 +243,8 @@ public class MappingDataBase implements MappingData {
 
     @Override
     public @Nullable FullMappings getFullItemMappings() {
-        if (itemMappings instanceof FullMappings) {
-            return (FullMappings) itemMappings;
+        if (itemMappings instanceof FullMappings fullItemMappings) {
+            return fullItemMappings;
         }
         return null;
     }
@@ -241,7 +260,15 @@ public class MappingDataBase implements MappingData {
     }
 
     @Override
-    public @Nullable Mappings getBlockEntityMappings() {
+    public @Nullable FullMappings getFullBlockMappings() {
+        if (blockMappings instanceof FullMappings fullBlockMappings) {
+            return fullBlockMappings;
+        }
+        return null;
+    }
+
+    @Override
+    public @Nullable FullMappings getBlockEntityMappings() {
         return blockEntityMappings;
     }
 
@@ -255,6 +282,14 @@ public class MappingDataBase implements MappingData {
         return soundMappings;
     }
 
+    @Override
+    public @Nullable FullMappings getFullSoundMappings() {
+        if (soundMappings instanceof FullMappings fullSoundMappings) {
+            return fullSoundMappings;
+        }
+        return null;
+    }
+
     @Override
     public @Nullable Mappings getStatisticsMappings() {
         return statisticsMappings;
@@ -300,6 +335,11 @@ public class MappingDataBase implements MappingData {
         return recipeSerializerMappings;
     }
 
+    @Override
+    public @Nullable IntSet changedBlocks() {
+        return changedBlocks;
+    }
+
     protected Logger getLogger() {
         return Via.getPlatform().getLogger();
     }

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

@@ -210,7 +210,7 @@ public class MappingDataLoader {
             return null;
         }
 
-        final int mappedSize = tag.getIntTag("mappedSize").asInt();
+        final int mappedSize = tag.getInt("mappedSize", -1);
         final byte strategy = tag.getByteTag("id").asByte();
         final V mappings;
         if (strategy == DIRECT_ID) {

api/src/main/java/com/viaversion/viaversion/api/data/entity/EntityTracker.java

@@ -82,6 +82,11 @@ public interface EntityTracker {
      */
     void clearEntities();
 
+    /**
+     * Clears all stored data, including entity types, entity data and client entity id.
+     */
+    void clear();
+
     /**
      * Returns the stored entity data if an entity with the id is tracked, else null.
      * If no data has been initialized yet, it will be done and returned by this method.
@@ -123,6 +128,20 @@ 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.
@@ -166,6 +185,20 @@ public interface EntityTracker {
      */
     void setCurrentWorld(String currentWorld);
 
+    /**
+     * Returns the id of the current dimension, or -1 if unset (i.e. before 1.20.5).
+     *
+     * @return id of the current dimension, or -1 if unset
+     */
+    int currentDimensionId();
+
+    /**
+     * Sets the id of the current dimension.
+     *
+     * @param currentDimensionId id of the current dimension
+     */
+    void setCurrentDimensionId(int currentDimensionId);
+
     int biomesSent();
 
     void setBiomesSent(int biomesSent);

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/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/BlockFace.java

@@ -33,7 +33,6 @@ public enum BlockFace {
     TOP((byte) 0, (byte) 1, (byte) 0, EnumAxis.Y),
     BOTTOM((byte) 0, (byte) -1, (byte) 0, EnumAxis.Y);
 
-    public static final BlockFace[] HORIZONTAL = {NORTH, SOUTH, EAST, WEST};
     private static final Map<BlockFace, BlockFace> opposites = new EnumMap<>(BlockFace.class);
 
     static {

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 +22,35 @@
  */
 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 record GameProfile(@Nullable String name, @Nullable UUID id, Property[] properties, boolean dynamic) {
+
+    public GameProfile(@Nullable final String name, @Nullable final UUID id, final Property[] properties) {
+        this(name, id, properties, true);
+    }
+
+    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 +23,8 @@
 package com.viaversion.viaversion.api.minecraft;
 
 import it.unimi.dsi.fastutil.ints.Int2IntFunction;
+import java.util.function.Function;
+import java.util.function.Supplier;
 
 public interface Holder<T> {
 
@@ -88,5 +90,24 @@ public interface Holder<T> {
      * @param rewriteFunction the function to rewrite the id
      * @return a new holder with the id rewritten, or self
      */
-    Holder<T> updateId(final Int2IntFunction rewriteFunction);
+    default Holder<T> updateId(final Int2IntFunction rewriteFunction) {
+        return this.updateId(rewriteFunction, null);
+    }
+
+    /**
+     * Returns a new holder with the id rewritten using the given function, or self if this is a direct holder or the id did not change.
+     *
+     * @param rewriteFunction the function to rewrite the id
+     * @param ifMissing       a supplier that provides a new holder if the id is missing (i.e. -1)
+     * @return a new holder with the id rewritten, or self
+     */
+    Holder<T> updateId(Int2IntFunction rewriteFunction, Supplier<Holder<T>> ifMissing);
+
+    /**
+     * 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/HolderSet.java

@@ -22,7 +22,11 @@
  */
 package com.viaversion.viaversion.api.minecraft;
 
+import com.viaversion.nbt.tag.ListTag;
+import com.viaversion.nbt.tag.StringTag;
+import com.viaversion.nbt.tag.Tag;
 import it.unimi.dsi.fastutil.ints.Int2IntFunction;
+import java.util.function.Function;
 
 /**
  * Set of ids that either holds a string tag key or an array of ids.
@@ -32,7 +36,7 @@ public interface HolderSet {
     /**
      * Creates a new holder set for the given tag.
      *
-     * @param tagKey the tag key
+     * @param tagKey the tag key, not including '#'
      * @return a new holder set
      */
     static HolderSet of(final String tagKey) {
@@ -49,10 +53,29 @@ public interface HolderSet {
         return new HolderSetImpl.Ids(ids);
     }
 
+    static HolderSet fromTag(final Tag tag, final Function<String, Integer> mappingFunction) {
+        if (tag instanceof StringTag stringTag) {
+            if (stringTag.getValue().startsWith("#")) {
+                return HolderSet.of(stringTag.getValue().substring(1));
+            }
+
+            final int id = mappingFunction.apply(stringTag.getValue());
+            return HolderSet.of(new int[]{id});
+        } else if (tag instanceof ListTag<?> listTag) {
+            final int[] ids = new int[listTag.size()];
+            for (int i = 0; i < listTag.size(); i++) {
+                final String value = ((StringTag) listTag.get(i)).getValue();
+                ids[i] = mappingFunction.apply(value);
+            }
+            return HolderSet.of(ids);
+        }
+        throw new IllegalArgumentException();
+    }
+
     /**
-     * Gets the tag key.
+     * Gets the tag key, not including '#'.
      *
-     * @return the tag key
+     * @return the tag key without a '#'
      * @see #hasTagKey()
      */
     String tagKey();

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 +24,8 @@ package com.viaversion.viaversion.api.minecraft;
 
 import com.google.common.base.Preconditions;
 import it.unimi.dsi.fastutil.ints.Int2IntFunction;
+import java.util.function.Function;
+import java.util.function.Supplier;
 
 record IdHolder<T>(int id) implements Holder<T> {
 
@@ -47,14 +49,22 @@ record IdHolder<T>(int id) implements Holder<T> {
     }
 
     @Override
-    public Holder<T> updateId(final Int2IntFunction rewriteFunction) {
+    public Holder<T> updateId(final Int2IntFunction rewriteFunction, final Supplier<Holder<T>> ifMissing) {
         final int rewrittenId = rewriteFunction.applyAsInt(id);
         if (rewrittenId == id) {
             return this;
         }
         if (rewrittenId == -1) {
+            if (ifMissing != null) {
+                return ifMissing.get();
+            }
             throw new IllegalArgumentException("Received invalid id in updateId");
         }
         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

@@ -121,7 +121,7 @@ public final class Particle implements IdHolder, Copyable {
 
         @Override
         public ParticleData<T> copy() {
-            return new ParticleData<>(type, copy(value));
+            return new ParticleData<>(type, Copyable.copy(value));
         }
 
         @Override

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

@@ -0,0 +1,37 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft;
+
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+/**
+ * Profile that can be either dynamically filled by the client or is already static.
+ * The additional fields are optional overrides.
+ */
+public record ResolvableProfile(GameProfile profile, @Nullable String bodyTexture, @Nullable String capeTexture,
+                                @Nullable String elytraTexture, @Nullable Integer modelType) {
+
+    public ResolvableProfile(final GameProfile profile) {
+        this(profile, null, null, null, null);
+    }
+}

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

@@ -22,11 +22,21 @@
  */
 package com.viaversion.viaversion.api.minecraft;
 
+import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 public record SoundEvent(String identifier, @Nullable Float fixedRange) {
 
+    private static final Holder<SoundEvent> UNKNOWN = Holder.of(new SoundEvent("viaversion:unknown", 0F));
+
     public SoundEvent withIdentifier(final String identifier) {
         return new SoundEvent(identifier, this.fixedRange);
     }
+
+    public static @Nullable Holder<SoundEvent> rewriteHolder(@Nullable final Holder<SoundEvent> holder, final Int2IntFunction soundRewriteFunction) {
+        if (holder == null) {
+            return null;
+        }
+        return holder.updateId(soundRewriteFunction, () -> UNKNOWN);
+    }
 }

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

@@ -23,6 +23,8 @@
 package com.viaversion.viaversion.api.minecraft;
 
 import it.unimi.dsi.fastutil.ints.Int2IntFunction;
+import java.util.function.Function;
+import java.util.function.Supplier;
 
 record ValueHolder<T>(T value) implements Holder<T> {
 
@@ -42,7 +44,13 @@ record ValueHolder<T>(T value) implements Holder<T> {
     }
 
     @Override
-    public Holder<T> updateId(final Int2IntFunction rewriteFunction) {
+    public Holder<T> updateId(final Int2IntFunction rewriteFunction, final Supplier<Holder<T>> ifMissing) {
         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/Vector3d.java

@@ -0,0 +1,28 @@
+/*
+ * 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 record Vector3d(double x, double y, double z) {
+
+    public static final Vector3d ZERO = new Vector3d(0, 0, 0);
+}

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

@@ -0,0 +1,64 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.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);
+
+        Key entity(int id);
+
+        Key blockEntity(int id);
+
+        Key sound(int id);
+
+        Key key(MappingData.MappingType mappingType, int id);
+
+        int id(MappingData.MappingType mappingType, String identifier);
+
+        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/DelegatingOps.java

@@ -0,0 +1,110 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.codec;
+
+import com.viaversion.viaversion.api.type.Type;
+import java.util.function.Consumer;
+
+public class DelegatingOps implements Ops {
+
+    private final Ops delegate;
+
+    public DelegatingOps(final Ops delegate) {
+        this.delegate = delegate;
+    }
+
+    @Override
+    public CodecContext context() {
+        return delegate.context();
+    }
+
+    @Override
+    public void writeByte(final byte b) {
+        delegate.writeByte(b);
+    }
+
+    @Override
+    public void writeBytes(final byte[] array) {
+        delegate.writeBytes(array);
+    }
+
+    @Override
+    public void writeBoolean(final boolean b) {
+        delegate.writeBoolean(b);
+    }
+
+    @Override
+    public void writeShort(final short s) {
+        delegate.writeShort(s);
+    }
+
+    @Override
+    public void writeString(final CharSequence sequence) {
+        delegate.writeString(sequence);
+    }
+
+    @Override
+    public void writeInt(final int i) {
+        delegate.writeInt(i);
+    }
+
+    @Override
+    public void writeLong(final long l) {
+        delegate.writeLong(l);
+    }
+
+    @Override
+    public void writeFloat(final float f) {
+        delegate.writeFloat(f);
+    }
+
+    @Override
+    public void writeDouble(final double d) {
+        delegate.writeDouble(d);
+    }
+
+    @Override
+    public void writeInts(final int[] array) {
+        delegate.writeInts(array);
+    }
+
+    @Override
+    public void writeLongs(final long[] array) {
+        delegate.writeLongs(array);
+    }
+
+    @Override
+    public void writeList(final Consumer<ListSerializer> consumer) {
+        delegate.writeList(consumer);
+    }
+
+    @Override
+    public void writeMap(final Consumer<MapSerializer> consumer) {
+        delegate.writeMap(consumer);
+    }
+
+    @Override
+    public <V> void write(final Type<V> type, final V value) {
+        delegate.write(type, value);
+    }
+}

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

@@ -0,0 +1,135 @@
+/*
+ * 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);
+
+        <T> MapSerializer writeInlinedMap(Type<T> valueType, T value);
+    }
+}

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

@@ -0,0 +1,108 @@
+/*
+ * 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);
+    }
+
+    @Override
+    public Key entity(final int id) {
+        return key(mappingData.getEntityMappings(), id);
+    }
+
+    @Override
+    public Key blockEntity(final int id) {
+        return key(mappingData.getBlockEntityMappings(), id);
+    }
+
+    @Override
+    public Key sound(final int id) {
+        return key(mappingData.getFullSoundMappings(), id);
+    }
+
+    @Override
+    public Key key(final MappingData.MappingType mappingType, final int id) {
+        return key(mappingData.getFullMappings(mappingType), id);
+    }
+
+    @Override
+    public int id(final MappingData.MappingType mappingType, final String identifier) {
+        final FullMappings mappings = mappingData.getFullMappings(mappingType);
+        return mapped ? mappings.mappedId(identifier) : mappings.id(identifier);
+    }
+
+    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/ThrowingOps.java

@@ -0,0 +1,104 @@
+/*
+ * 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 java.util.function.Consumer;
+
+public class ThrowingOps implements Ops {
+
+    @Override
+    public CodecContext context() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void writeByte(final byte b) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void writeBytes(final byte[] array) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void writeBoolean(final boolean b) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void writeShort(final short s) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void writeString(final CharSequence sequence) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void writeInt(final int i) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void writeLong(final long l) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void writeFloat(final float f) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void writeDouble(final double d) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void writeInts(final int[] array) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void writeLongs(final long[] array) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void writeList(final Consumer<ListSerializer> consumer) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void writeMap(final Consumer<MapSerializer> consumer) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public <V> void write(final Type<V> type, final V value) {
+        throw new UnsupportedOperationException();
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/codec/hash/Hasher.java

@@ -20,22 +20,26 @@
  * 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.codec.hash;
 
-import com.viaversion.viaversion.api.minecraft.entitydata.EntityData;
-import com.viaversion.viaversion.api.type.Type;
-import com.viaversion.viaversion.api.type.types.entitydata.EntityDataListType;
-import com.viaversion.viaversion.api.type.types.entitydata.EntityDataType1_12;
-import java.util.List;
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
 
-public final class Types1_12 {
+/**
+ * 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 {
 
     /**
-     * Entity data type for 1.12
+     * Returns the current hash value.
+     *
+     * @return the current hash value
      */
-    public static final Type<EntityData> ENTITY_DATA = new EntityDataType1_12();
+    int hash();
+
     /**
-     * Entity data list type for 1.12
+     * Resets the hasher to its initial state.
      */
-    public static final Type<List<EntityData>> ENTITY_DATA_LIST = new EntityDataListType(ENTITY_DATA);
+    void reset();
 }

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

@@ -23,6 +23,8 @@
 package com.viaversion.viaversion.api.minecraft.data;
 
 import com.google.common.base.Preconditions;
+import com.viaversion.viaversion.util.ArrayUtil;
+import com.viaversion.viaversion.util.Copyable;
 import io.netty.buffer.ByteBuf;
 import java.util.Objects;
 
@@ -61,7 +63,7 @@ final class FilledStructuredData<T> implements StructuredData<T> {
 
     @Override
     public StructuredData<T> copy() {
-        return new FilledStructuredData<>(this.key, this.copy(this.value), this.id);
+        return new FilledStructuredData<>(this.key, Copyable.copy(this.value), this.id);
     }
 
     @Override
@@ -101,7 +103,7 @@ final class FilledStructuredData<T> implements StructuredData<T> {
     public String toString() {
         return "FilledStructuredData{" +
             "key=" + key +
-            ", value=" + value +
+            ", value=" + ArrayUtil.toString(value) +
             ", id=" + id +
             '}';
     }

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

@@ -241,7 +241,7 @@ public final class StructuredDataContainer implements Copyable {
     /**
      * Sets the lookup for serializer ids. Required to call most of the other methods.
      *
-     * @param protocol    protocol to retreive the id of the serializer from
+     * @param protocol    protocol to retrieve the id of the serializer from
      * @param mappedNames if the names are mapped (true if structures from the mapped version are added, false for the unmapped version)
      */
     public void setIdLookup(final Protocol<?, ?, ?, ?> protocol, final boolean mappedNames) {
@@ -284,6 +284,10 @@ public final class StructuredDataContainer implements Copyable {
         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

@@ -27,57 +27,72 @@ import com.viaversion.nbt.tag.Tag;
 import com.viaversion.viaversion.api.minecraft.EitherHolder;
 import com.viaversion.viaversion.api.minecraft.GameProfile;
 import com.viaversion.viaversion.api.minecraft.Holder;
-import com.viaversion.viaversion.api.minecraft.HolderSet;
 import com.viaversion.viaversion.api.minecraft.PaintingVariant;
+import com.viaversion.viaversion.api.minecraft.ResolvableProfile;
 import com.viaversion.viaversion.api.minecraft.SoundEvent;
-import com.viaversion.viaversion.api.minecraft.item.Item;
+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.AdventureModePredicate.AdventureModePredicateType1_21_5;
 import com.viaversion.viaversion.api.minecraft.item.data.ArmorTrim;
 import com.viaversion.viaversion.api.minecraft.item.data.AttributeModifiers1_20_5;
 import com.viaversion.viaversion.api.minecraft.item.data.AttributeModifiers1_21;
 import com.viaversion.viaversion.api.minecraft.item.data.BannerPatternLayer;
 import com.viaversion.viaversion.api.minecraft.item.data.Bee;
+import com.viaversion.viaversion.api.minecraft.item.data.BlockEntityData;
 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.DebugStickState;
 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;
 import com.viaversion.viaversion.api.minecraft.item.data.FoodProperties1_21_2;
 import com.viaversion.viaversion.api.minecraft.item.data.Instrument1_20_5;
 import com.viaversion.viaversion.api.minecraft.item.data.Instrument1_21_2;
+import com.viaversion.viaversion.api.minecraft.item.data.ItemModel;
 import com.viaversion.viaversion.api.minecraft.item.data.JukeboxPlayable;
+import com.viaversion.viaversion.api.minecraft.item.data.LockCode;
 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.Repairable;
 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.EntityData;
 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.EitherType;
-import com.viaversion.viaversion.api.type.types.version.Types1_20_5;
-import com.viaversion.viaversion.api.type.types.version.Types1_21;
-import com.viaversion.viaversion.api.type.types.version.Types1_21_2;
-import com.viaversion.viaversion.api.type.types.version.Types1_21_4;
-import com.viaversion.viaversion.api.type.types.version.Types1_21_5;
+import com.viaversion.viaversion.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);
@@ -86,20 +101,20 @@ public record StructuredDataKey<T>(String identifier, Type<T> type) {
     public static final StructuredDataKey<Integer> DAMAGE = new StructuredDataKey<>("damage", Types.VAR_INT);
     public static final StructuredDataKey<Unbreakable> UNBREAKABLE1_20_5 = new StructuredDataKey<>("unbreakable", Unbreakable.TYPE);
     public static final StructuredDataKey<Unit> UNBREAKABLE1_21_5 = new StructuredDataKey<>("unbreakable", Types.EMPTY);
-    public static final StructuredDataKey<Tag> CUSTOM_NAME = new StructuredDataKey<>("custom_name", Types.TAG);
-    public static final StructuredDataKey<Tag> ITEM_NAME = new StructuredDataKey<>("item_name", Types.TAG);
-    public static final StructuredDataKey<String> ITEM_MODEL = new StructuredDataKey<>("item_model", Types.STRING);
-    public static final StructuredDataKey<Tag[]> LORE = new StructuredDataKey<>("lore", new ArrayType<>(Types.TAG, 256));
-    public static final StructuredDataKey<Integer> RARITY = new StructuredDataKey<>("rarity", Types.VAR_INT);
+    public static final StructuredDataKey<Tag> CUSTOM_NAME = new StructuredDataKey<>("custom_name", Types.TEXT_COMPONENT_TAG);
+    public static final StructuredDataKey<Tag> ITEM_NAME = new StructuredDataKey<>("item_name", Types.TEXT_COMPONENT_TAG);
+    public static final StructuredDataKey<ItemModel> ITEM_MODEL = new StructuredDataKey<>("item_model", ItemModel.TYPE);
+    public static final StructuredDataKey<Tag[]> LORE = new StructuredDataKey<>("lore", new ArrayType<>(Types.TEXT_COMPONENT_TAG, 256));
+    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_PLACE_ON1_21_5 = new StructuredDataKey<>("can_place_on", new AdventureModePredicateType1_21_5(Types1_21_5.STRUCTURED_DATA_ARRAY));
     public static final StructuredDataKey<AdventureModePredicate> CAN_BREAK1_20_5 = new StructuredDataKey<>("can_break", AdventureModePredicate.TYPE1_20_5);
-    public static final StructuredDataKey<AdventureModePredicate> CAN_BREAK1_21_5 = new StructuredDataKey<>("can_break", new AdventureModePredicateType1_21_5(Types1_21_5.STRUCTURED_DATA_ARRAY));
     public static final StructuredDataKey<AttributeModifiers1_20_5> ATTRIBUTE_MODIFIERS1_20_5 = new StructuredDataKey<>("attribute_modifiers", AttributeModifiers1_20_5.TYPE);
     public static final StructuredDataKey<AttributeModifiers1_21> ATTRIBUTE_MODIFIERS1_21 = new StructuredDataKey<>("attribute_modifiers", AttributeModifiers1_21.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);
@@ -113,21 +128,19 @@ 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<Item> USE_REMAINDER1_21_5 = new StructuredDataKey<>("use_remainder", Types1_21_5.ITEM);
     public static final StructuredDataKey<UseCooldown> USE_COOLDOWN = new StructuredDataKey<>("use_cooldown", UseCooldown.TYPE);
     public static final StructuredDataKey<Unit> FIRE_RESISTANT = new StructuredDataKey<>("fire_resistant", Types.EMPTY);
     public static final StructuredDataKey<DamageResistant> DAMAGE_RESISTANT = new StructuredDataKey<>("damage_resistant", DamageResistant.TYPE);
     public static final StructuredDataKey<ToolProperties> TOOL1_20_5 = new StructuredDataKey<>("tool", ToolProperties.TYPE1_20_5);
     public static final StructuredDataKey<ToolProperties> TOOL1_21_5 = new StructuredDataKey<>("tool", ToolProperties.TYPE1_21_5);
     public static final StructuredDataKey<Weapon> WEAPON = new StructuredDataKey<>("weapon", Weapon.TYPE);
-    public static final StructuredDataKey<Integer> ENCHANTABLE = new StructuredDataKey<>("enchantable", Types.VAR_INT);
+    public static final StructuredDataKey<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<HolderSet> REPAIRABLE = new StructuredDataKey<>("repairable", Types.HOLDER_SET);
+    public static final StructuredDataKey<Equippable> EQUIPPABLE1_21_6 = new StructuredDataKey<>("equippable", Equippable.TYPE1_21_6);
+    public static final StructuredDataKey<Repairable> REPAIRABLE = new StructuredDataKey<>("repairable", Repairable.TYPE);
     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<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);
@@ -138,30 +151,22 @@ public record StructuredDataKey<T>(String identifier, Type<T> type) {
     public static final StructuredDataKey<Integer> MAP_ID = new StructuredDataKey<>("map_id", Types.VAR_INT);
     public static final StructuredDataKey<CompoundTag> MAP_DECORATIONS = new StructuredDataKey<>("map_decorations", Types.COMPOUND_TAG);
     public static final StructuredDataKey<Integer> MAP_POST_PROCESSING = new StructuredDataKey<>("map_post_processing", Types.VAR_INT);
-    public static final StructuredDataKey<Item[]> CHARGED_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[]> CHARGED_PROJECTILES1_21_5 = new StructuredDataKey<>("charged_projectiles", Types1_21_5.ITEM_ARRAY);
-    public static final StructuredDataKey<Item[]> BUNDLE_CONTENTS1_20_5 = new StructuredDataKey<>("bundle_contents", Types1_20_5.ITEM_ARRAY);
-    public static final StructuredDataKey<Item[]> BUNDLE_CONTENTS1_21 = new StructuredDataKey<>("bundle_contents", Types1_21.ITEM_ARRAY);
-    public static final StructuredDataKey<Item[]> BUNDLE_CONTENTS1_21_2 = new StructuredDataKey<>("bundle_contents", Types1_21_2.ITEM_ARRAY);
-    public static final StructuredDataKey<Item[]> BUNDLE_CONTENTS1_21_4 = new StructuredDataKey<>("bundle_contents", Types1_21_4.ITEM_ARRAY);
-    public static final StructuredDataKey<Item[]> BUNDLE_CONTENTS1_21_5 = new StructuredDataKey<>("bundle_contents", Types1_21_5.ITEM_ARRAY);
     public static final StructuredDataKey<PotionContents> POTION_CONTENTS1_20_5 = new StructuredDataKey<>("potion_contents", PotionContents.TYPE1_20_5);
     public static final StructuredDataKey<PotionContents> POTION_CONTENTS1_21_2 = new StructuredDataKey<>("potion_contents", PotionContents.TYPE1_21_2);
     public static final StructuredDataKey<Float> POTION_DURATION_SCALE = new StructuredDataKey<>("potion_duration_scale", Types.FLOAT);
     public static final StructuredDataKey<SuspiciousStewEffect[]> SUSPICIOUS_STEW_EFFECTS = new StructuredDataKey<>("suspicious_stew_effects", SuspiciousStewEffect.ARRAY_TYPE);
-    public static final StructuredDataKey<FilterableString[]> WRITABLE_BOOK_CONTENT = new StructuredDataKey<>("writable_book_content", FilterableString.ARRAY_TYPE);
+    public static final StructuredDataKey<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<DebugStickState> DEBUG_STICK_STATE = new StructuredDataKey<>("debug_stick_state", DebugStickState.TYPE);
+    public static final StructuredDataKey<CompoundTag> ENTITY_DATA1_20_5 = new StructuredDataKey<>("entity_data", Types.COMPOUND_TAG);
+    public static final StructuredDataKey<EntityData> ENTITY_DATA1_21_9 = new StructuredDataKey<>("entity_data", EntityData.TYPE);
     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<CompoundTag> BLOCK_ENTITY_DATA1_20_5 = new StructuredDataKey<>("block_entity_data", Types.COMPOUND_TAG);
+    public static final StructuredDataKey<BlockEntityData> BLOCK_ENTITY_DATA1_21_9 = new StructuredDataKey<>("block_entity_data", BlockEntityData.TYPE);
     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);
@@ -169,51 +174,58 @@ public record StructuredDataKey<T>(String identifier, Type<T> type) {
     public static final StructuredDataKey<Integer> OMINOUS_BOTTLE_AMPLIFIER = new StructuredDataKey<>("ominous_bottle_amplifier", Types.VAR_INT);
     public static final StructuredDataKey<JukeboxPlayable> JUKEBOX_PLAYABLE1_21 = new StructuredDataKey<>("jukebox_playable", JukeboxPlayable.TYPE1_21);
     public static final StructuredDataKey<JukeboxPlayable> JUKEBOX_PLAYABLE1_21_5 = new StructuredDataKey<>("jukebox_playable", JukeboxPlayable.TYPE1_21_5);
-    public static final StructuredDataKey<String> PROVIDES_BANNER_PATTERNS = new StructuredDataKey<>("provides_banner_patterns", Types.STRING);
+    public static final StructuredDataKey<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<GameProfile> PROFILE1_20_5 = new StructuredDataKey<>("profile", Types.GAME_PROFILE);
+    public static final StructuredDataKey<ResolvableProfile> PROFILE1_21_9 = new StructuredDataKey<>("profile", Types.RESOLVABLE_PROFILE);
+    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<Item[]> CONTAINER1_21_5 = new StructuredDataKey<>("container", Types1_21_5.ITEM_ARRAY);
     public static final StructuredDataKey<BlockStateProperties> BLOCK_STATE = new StructuredDataKey<>("block_state", BlockStateProperties.TYPE);
-    public static final StructuredDataKey<Bee[]> BEES = new StructuredDataKey<>("bees", Bee.ARRAY_TYPE);
-    public static final StructuredDataKey<Tag> LOCK = new StructuredDataKey<>("lock", Types.TAG);
+    public static final StructuredDataKey<Bee[]> BEES1_20_5 = new StructuredDataKey<>("bees", Bee.ARRAY_TYPE1_20_5);
+    public static final StructuredDataKey<Bee[]> BEES1_21_9 = new StructuredDataKey<>("bees", Bee.ARRAY_TYPE1_21_9);
+    public static final StructuredDataKey<Tag> LOCK1_20_5 = new StructuredDataKey<>("lock", Types.TAG);
+    public static final StructuredDataKey<LockCode> LOCK1_21_2 = new StructuredDataKey<>("lock", LockCode.TYPE);
     public static final StructuredDataKey<CompoundTag> CONTAINER_LOOT = new StructuredDataKey<>("container_loot", Types.COMPOUND_TAG);
     public static final StructuredDataKey<Holder<SoundEvent>> BREAK_SOUND = new StructuredDataKey<>("break_sound", Types.SOUND_EVENT);
 
-    public static final StructuredDataKey<Integer> VILLAGER_VARIANT = new StructuredDataKey<>("villager/variant", Types.VAR_INT);
+    public static final StructuredDataKey<Integer> 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", Types.VAR_INT);
-    public static final StructuredDataKey<Integer> FOX_VARIANT = new StructuredDataKey<>("fox/variant", Types.VAR_INT);
-    public static final StructuredDataKey<Integer> SALMON_SIZE = new StructuredDataKey<>("salmon/size", Types.VAR_INT);
-    public static final StructuredDataKey<Integer> PARROT_VARIANT = new StructuredDataKey<>("parrot/variant", Types.VAR_INT);
-    public static final StructuredDataKey<Integer> TROPICAL_FISH_PATTERN = new StructuredDataKey<>("tropical_fish/pattern", Types.VAR_INT);
-    public static final StructuredDataKey<Integer> TROPICAL_FISH_BASE_COLOR = new StructuredDataKey<>("tropical_fish/base_color", Types.VAR_INT);
-    public static final StructuredDataKey<Integer> TROPICAL_FISH_PATTERN_COLOR = new StructuredDataKey<>("tropical_fish/pattern_color", Types.VAR_INT);
-    public static final StructuredDataKey<Integer> MOOSHROOM_VARIANT = new StructuredDataKey<>("mooshroom/variant", Types.VAR_INT);
-    public static final StructuredDataKey<Integer> RABBIT_VARIANT = new StructuredDataKey<>("rabbit/variant", Types.VAR_INT);
+    public static final StructuredDataKey<Integer> 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", 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", Types.VAR_INT);
-    public static final StructuredDataKey<Integer> AXOLOTL_VARIANT = new StructuredDataKey<>("axolotl/variant", Types.VAR_INT);
+    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", Types.VAR_INT);
-    public static final StructuredDataKey<Integer> SHEEP_COLOR = new StructuredDataKey<>("sheep/color", Types.VAR_INT);
-    public static final StructuredDataKey<Integer> SHULKER_COLOR = new StructuredDataKey<>("shulker/color", Types.VAR_INT);
+    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();
+    public static final StructuredDataKeys1_21_5 V1_21_9 = VersionedTypes.V1_21_9.structuredDataKeys();
 
     @Override
     public String toString() {

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

@@ -20,25 +20,31 @@
  * 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.data.version;
 
-import com.viaversion.viaversion.api.minecraft.chunks.ChunkSection;
-import com.viaversion.viaversion.api.minecraft.entitydata.EntityData;
+import com.viaversion.viaversion.api.minecraft.data.StructuredDataKey;
 import com.viaversion.viaversion.api.type.Type;
-import com.viaversion.viaversion.api.type.types.chunk.ChunkSectionType1_9;
-import com.viaversion.viaversion.api.type.types.entitydata.EntityDataListType;
-import com.viaversion.viaversion.api.type.types.entitydata.EntityDataType1_9;
+import it.unimi.dsi.fastutil.objects.ReferenceArraySet;
+import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
 
-public final class Types1_9 {
-    /**
-     * Entity data type for 1.9
-     */
-    public static final Type<EntityData> ENTITY_DATA = new EntityDataType1_9();
-    /**
-     * Entity data list type for 1.9
-     */
-    public static final Type<List<EntityData>> ENTITY_DATA_LIST = new EntityDataListType(ENTITY_DATA);
+public abstract class VersionedStructuredDataKeys {
 
-    public static final Type<ChunkSection> CHUNK_SECTION = new ChunkSectionType1_9();
+    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

@@ -22,8 +22,8 @@
  */
 package com.viaversion.viaversion.api.minecraft.entities;
 
-import java.util.HashMap;
-import java.util.Map;
+import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
+import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
 
 public class EntityTypes1_10 {
 
@@ -143,7 +143,7 @@ public class EntityTypes1_10 {
         SPIDER(52, ABSTRACT_MONSTER),
         CAVE_SPIDER(59, SPIDER);
 
-        private static final Map<Integer, EntityType> TYPES = new HashMap<>();
+        private static final Int2ObjectMap<EntityType> TYPES;
 
         private final int id;
         private final EntityType parent;
@@ -184,7 +184,9 @@ public class EntityTypes1_10 {
         }
 
         static {
-            for (EntityType type : EntityType.values()) {
+            final EntityType[] values = EntityType.values();
+            TYPES = new Int2ObjectOpenHashMap<>(values.length);
+            for (EntityType type : values) {
                 TYPES.put(type.id, type);
             }
         }
@@ -230,7 +232,7 @@ public class EntityTypes1_10 {
         SPECTRAL_ARROW(91, EntityType.SPECTRAL_ARROW),
         DRAGON_FIREBALL(93, EntityType.DRAGON_FIREBALL);
 
-        private static final Map<Integer, Map<Integer, ObjectType>> TYPES = new HashMap<>();
+        private static final Int2ObjectMap<Int2ObjectMap<ObjectType>> TYPES = new Int2ObjectOpenHashMap<>();
 
         private final int id;
         private final int data;
@@ -238,7 +240,7 @@ public class EntityTypes1_10 {
 
         static {
             for (ObjectType type : ObjectType.values()) {
-                TYPES.computeIfAbsent(type.id, k -> new HashMap<>()).put(type.data, type);
+                TYPES.computeIfAbsent(type.id, k -> new Int2ObjectOpenHashMap<>()).put(type.data, type);
             }
         }
 
@@ -268,7 +270,7 @@ public class EntityTypes1_10 {
         }
 
         public static ObjectType findById(final int id, final int data) {
-            final Map<Integer, ObjectType> types = TYPES.get(id);
+            final Int2ObjectMap<ObjectType> types = TYPES.get(id);
             if (types == null) {
                 return null;
             }

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

@@ -22,8 +22,8 @@
  */
 package com.viaversion.viaversion.api.minecraft.entities;
 
-import java.util.HashMap;
-import java.util.Map;
+import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
+import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
 
 public class EntityTypes1_11 {
 
@@ -168,7 +168,7 @@ public class EntityTypes1_11 {
         EVOKER(34, ABSTRACT_MONSTER),
         VINDICATOR(36, ABSTRACT_MONSTER);
 
-        private static final Map<Integer, EntityType> TYPES = new HashMap<>();
+        private static final Int2ObjectMap<EntityType> TYPES;
 
         private final int id;
         private final EntityType parent;
@@ -209,7 +209,9 @@ public class EntityTypes1_11 {
         }
 
         static {
-            for (EntityType type : EntityType.values()) {
+            final EntityType[] values = EntityType.values();
+            TYPES = new Int2ObjectOpenHashMap<>(values.length);
+            for (EntityType type : values) {
                 TYPES.put(type.id, type);
             }
         }
@@ -257,7 +259,7 @@ public class EntityTypes1_11 {
         SPECTRAL_ARROW(91, EntityType.SPECTRAL_ARROW),
         DRAGON_FIREBALL(93, EntityType.DRAGON_FIREBALL);
 
-        private static final Map<Integer, Map<Integer, ObjectType>> TYPES = new HashMap<>();
+        private static final Int2ObjectMap<Int2ObjectMap<ObjectType>> TYPES = new Int2ObjectOpenHashMap<>();
 
         private final int id;
         private final int data;
@@ -265,7 +267,7 @@ public class EntityTypes1_11 {
 
         static {
             for (ObjectType type : ObjectType.values()) {
-                TYPES.computeIfAbsent(type.id, k -> new HashMap<>()).put(type.data, type);
+                TYPES.computeIfAbsent(type.id, k -> new Int2ObjectOpenHashMap<>()).put(type.data, type);
             }
         }
 
@@ -295,7 +297,7 @@ public class EntityTypes1_11 {
         }
 
         public static ObjectType findById(final int id, final int data) {
-            final Map<Integer, ObjectType> types = TYPES.get(id);
+            final Int2ObjectMap<ObjectType> types = TYPES.get(id);
             if (types == null) {
                 return null;
             }

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

@@ -22,8 +22,8 @@
  */
 package com.viaversion.viaversion.api.minecraft.entities;
 
-import java.util.HashMap;
-import java.util.Map;
+import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
+import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
 
 public class EntityTypes1_12 {
 
@@ -174,7 +174,7 @@ public class EntityTypes1_12 {
         EVOKER(34, SPELLCASTER_ILLAGER),
         ILLUSIONER(37, SPELLCASTER_ILLAGER);
 
-        private static final Map<Integer, EntityType> TYPES = new HashMap<>();
+        private static final Int2ObjectMap<EntityType> TYPES;
 
         private final int id;
         private final EntityType parent;
@@ -215,7 +215,9 @@ public class EntityTypes1_12 {
         }
 
         static {
-            for (EntityType type : EntityType.values()) {
+            final EntityType[] values = EntityType.values();
+            TYPES = new Int2ObjectOpenHashMap<>(values.length);
+            for (EntityType type : values) {
                 TYPES.put(type.id, type);
             }
         }
@@ -263,7 +265,7 @@ public class EntityTypes1_12 {
         SPECTRAL_ARROW(91, EntityType.SPECTRAL_ARROW),
         DRAGON_FIREBALL(93, EntityType.DRAGON_FIREBALL);
 
-        private static final Map<Integer, Map<Integer, ObjectType>> TYPES = new HashMap<>();
+        private static final Int2ObjectMap<Int2ObjectMap<ObjectType>> TYPES = new Int2ObjectOpenHashMap<>();
 
         private final int id;
         private final int data;
@@ -271,7 +273,7 @@ public class EntityTypes1_12 {
 
         static {
             for (ObjectType type : ObjectType.values()) {
-                TYPES.computeIfAbsent(type.id, k -> new HashMap<>()).put(type.data, type);
+                TYPES.computeIfAbsent(type.id, k -> new Int2ObjectOpenHashMap<>()).put(type.data, type);
             }
         }
 
@@ -301,7 +303,7 @@ public class EntityTypes1_12 {
         }
 
         public static ObjectType findById(final int id, final int data) {
-            final Map<Integer, ObjectType> types = TYPES.get(id);
+            final Int2ObjectMap<ObjectType> types = TYPES.get(id);
             if (types == null) {
                 return null;
             }

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

@@ -22,8 +22,8 @@
  */
 package com.viaversion.viaversion.api.minecraft.entities;
 
-import java.util.HashMap;
-import java.util.Map;
+import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
+import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
 
 public class EntityTypes1_13 {
 
@@ -185,7 +185,7 @@ public class EntityTypes1_13 {
         EVOKER(21, SPELLCASTER_ILLAGER),
         ILLUSIONER(31, SPELLCASTER_ILLAGER);
 
-        private static final Map<Integer, EntityType> TYPES = new HashMap<>();
+        private static final Int2ObjectMap<EntityType> TYPES;
 
         private final int id;
         private final EntityType parent;
@@ -226,7 +226,9 @@ public class EntityTypes1_13 {
         }
 
         static {
-            for (EntityType type : EntityType.values()) {
+            final EntityType[] values = EntityType.values();
+            TYPES = new Int2ObjectOpenHashMap<>(values.length);
+            for (EntityType type : values) {
                 TYPES.put(type.id, type);
             }
         }
@@ -275,7 +277,7 @@ public class EntityTypes1_13 {
         DRAGON_FIREBALL(93, EntityType.DRAGON_FIREBALL),
         TRIDENT(94, EntityType.TRIDENT);
 
-        private static final Map<Integer, Map<Integer, ObjectType>> TYPES = new HashMap<>();
+        private static final Int2ObjectMap<Int2ObjectMap<ObjectType>> TYPES = new Int2ObjectOpenHashMap<>();
 
         private final int id;
         private final int data;
@@ -283,7 +285,7 @@ public class EntityTypes1_13 {
 
         static {
             for (ObjectType type : ObjectType.values()) {
-                TYPES.computeIfAbsent(type.id, k -> new HashMap<>()).put(type.data, type);
+                TYPES.computeIfAbsent(type.id, k -> new Int2ObjectOpenHashMap<>()).put(type.data, type);
             }
         }
 
@@ -313,7 +315,7 @@ public class EntityTypes1_13 {
         }
 
         public static ObjectType findById(final int id, final int data) {
-            final Map<Integer, ObjectType> types = TYPES.get(id);
+            final Int2ObjectMap<ObjectType> types = TYPES.get(id);
             if (types == null) {
                 return null;
             }

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/EntityTypes1_14.java

@@ -213,7 +213,7 @@ public enum EntityTypes1_14 implements EntityType {
 
     EntityTypes1_14(final EntityType parent) {
         this.parent = parent;
-        this.identifier =  Key.namespaced(name().toLowerCase(Locale.ROOT));
+        this.identifier = Key.namespaced(name().toLowerCase(Locale.ROOT));
     }
 
     EntityTypes1_14(final EntityType parent, @Nullable final String identifier) {

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/EntityTypes1_15.java

@@ -214,7 +214,7 @@ public enum EntityTypes1_15 implements EntityType {
 
     EntityTypes1_15(final EntityType parent) {
         this.parent = parent;
-        this.identifier =  Key.namespaced(name().toLowerCase(Locale.ROOT));
+        this.identifier = Key.namespaced(name().toLowerCase(Locale.ROOT));
     }
 
     EntityTypes1_15(final EntityType parent, @Nullable final String identifier) {

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/EntityTypes1_16.java

@@ -218,7 +218,7 @@ public enum EntityTypes1_16 implements EntityType {
 
     EntityTypes1_16(final EntityType parent) {
         this.parent = parent;
-        this.identifier =  Key.namespaced(name().toLowerCase(Locale.ROOT));
+        this.identifier = Key.namespaced(name().toLowerCase(Locale.ROOT));
     }
 
     EntityTypes1_16(final EntityType parent, @Nullable final String identifier) {

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/EntityTypes1_16_2.java

@@ -221,7 +221,7 @@ public enum EntityTypes1_16_2 implements EntityType {
 
     EntityTypes1_16_2(final EntityType parent) {
         this.parent = parent;
-        this.identifier =  Key.namespaced(name().toLowerCase(Locale.ROOT));
+        this.identifier = Key.namespaced(name().toLowerCase(Locale.ROOT));
     }
 
     EntityTypes1_16_2(final EntityType parent, @Nullable final String identifier) {

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/EntityTypes1_17.java

@@ -227,7 +227,7 @@ public enum EntityTypes1_17 implements EntityType {
 
     EntityTypes1_17(final EntityType parent) {
         this.parent = parent;
-        this.identifier =  Key.namespaced(name().toLowerCase(Locale.ROOT));
+        this.identifier = Key.namespaced(name().toLowerCase(Locale.ROOT));
     }
 
     EntityTypes1_17(final EntityType parent, @Nullable final String identifier) {

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/EntityTypes1_19.java

@@ -232,7 +232,7 @@ public enum EntityTypes1_19 implements EntityType {
 
     EntityTypes1_19(final EntityType parent) {
         this.parent = parent;
-        this.identifier =  Key.namespaced(name().toLowerCase(Locale.ROOT));
+        this.identifier = Key.namespaced(name().toLowerCase(Locale.ROOT));
     }
 
     EntityTypes1_19(final EntityType parent, @Nullable final String identifier) {

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/EntityTypes1_19_3.java

@@ -233,7 +233,7 @@ public enum EntityTypes1_19_3 implements EntityType {
 
     EntityTypes1_19_3(final EntityType parent) {
         this.parent = parent;
-        this.identifier =  Key.namespaced(name().toLowerCase(Locale.ROOT));
+        this.identifier = Key.namespaced(name().toLowerCase(Locale.ROOT));
     }
 
     EntityTypes1_19_3(final EntityType parent, @Nullable final String identifier) {

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/EntityTypes1_19_4.java

@@ -240,7 +240,7 @@ public enum EntityTypes1_19_4 implements EntityType {
 
     EntityTypes1_19_4(final EntityType parent) {
         this.parent = parent;
-        this.identifier =  Key.namespaced(name().toLowerCase(Locale.ROOT));
+        this.identifier = Key.namespaced(name().toLowerCase(Locale.ROOT));
     }
 
     EntityTypes1_19_4(final EntityType parent, @Nullable final String identifier) {

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/EntityTypes1_20_3.java

@@ -242,7 +242,7 @@ public enum EntityTypes1_20_3 implements EntityType {
 
     EntityTypes1_20_3(final EntityType parent) {
         this.parent = parent;
-        this.identifier =  Key.namespaced(name().toLowerCase(Locale.ROOT));
+        this.identifier = Key.namespaced(name().toLowerCase(Locale.ROOT));
     }
 
     EntityTypes1_20_3(final EntityType parent, @Nullable final String identifier) {

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/EntityTypes1_20_5.java

@@ -248,7 +248,7 @@ public enum EntityTypes1_20_5 implements EntityType {
 
     EntityTypes1_20_5(final EntityType parent) {
         this.parent = parent;
-        this.identifier =  Key.namespaced(name().toLowerCase(Locale.ROOT));
+        this.identifier = Key.namespaced(name().toLowerCase(Locale.ROOT));
     }
 
     EntityTypes1_20_5(final EntityType parent, @Nullable final String identifier) {

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/EntityTypes1_21_2.java

@@ -272,7 +272,7 @@ public enum EntityTypes1_21_2 implements EntityType {
 
     EntityTypes1_21_2(final EntityType parent) {
         this.parent = parent;
-        this.identifier =  Key.namespaced(name().toLowerCase(Locale.ROOT));
+        this.identifier = Key.namespaced(name().toLowerCase(Locale.ROOT));
     }
 
     EntityTypes1_21_2(final EntityType parent, @Nullable final String identifier) {

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/EntityTypes1_21_4.java

@@ -271,7 +271,7 @@ public enum EntityTypes1_21_4 implements EntityType {
 
     EntityTypes1_21_4(final EntityType parent) {
         this.parent = parent;
-        this.identifier =  Key.namespaced(name().toLowerCase(Locale.ROOT));
+        this.identifier = Key.namespaced(name().toLowerCase(Locale.ROOT));
     }
 
     EntityTypes1_21_4(final EntityType parent, @Nullable final String identifier) {

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_21_9.java

@@ -0,0 +1,323 @@
+/*
+ * 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_9 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),
+
+    // Players
+    AVATAR(LIVING_ENTITY, null),
+    MANNEQUIN(AVATAR),
+    PLAYER(AVATAR),
+
+    // 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),
+    COPPER_GOLEM(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_9(final EntityType parent) {
+        this.parent = parent;
+        this.identifier = Key.namespaced(name().toLowerCase(Locale.ROOT));
+    }
+
+    EntityTypes1_21_9(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

@@ -22,8 +22,8 @@
  */
 package com.viaversion.viaversion.api.minecraft.entities;
 
-import java.util.HashMap;
-import java.util.Map;
+import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
+import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
 
 public class EntityTypes1_8 {
 
@@ -135,7 +135,7 @@ public class EntityTypes1_8 {
         SPIDER(52, ABSTRACT_MONSTER),
         CAVE_SPIDER(59, SPIDER);
 
-        private static final Map<Integer, EntityType> TYPES = new HashMap<>();
+        private static final Int2ObjectMap<EntityType> TYPES;
 
         private final int id;
         private final EntityType parent;
@@ -176,7 +176,9 @@ public class EntityTypes1_8 {
         }
 
         static {
-            for (EntityType type : EntityType.values()) {
+            final EntityType[] values = EntityType.values();
+            TYPES = new Int2ObjectOpenHashMap<>(values.length);
+            for (EntityType type : values) {
                 TYPES.put(type.id, type);
             }
         }
@@ -218,7 +220,7 @@ public class EntityTypes1_8 {
         ARMOR_STAND(78, EntityType.ARMOR_STAND),
         FISHIHNG_HOOK(90, EntityType.FISHING_HOOK);
 
-        private static final Map<Integer, Map<Integer, ObjectType>> TYPES = new HashMap<>();
+        private static final Int2ObjectMap<Int2ObjectMap<ObjectType>> TYPES = new Int2ObjectOpenHashMap<>();
 
         private final int id;
         private final int data;
@@ -226,7 +228,7 @@ public class EntityTypes1_8 {
 
         static {
             for (ObjectType type : ObjectType.values()) {
-                TYPES.computeIfAbsent(type.id, k -> new HashMap<>()).put(type.data, type);
+                TYPES.computeIfAbsent(type.id, k -> new Int2ObjectOpenHashMap<>()).put(type.data, type);
             }
         }
 
@@ -256,7 +258,7 @@ public class EntityTypes1_8 {
         }
 
         public static ObjectType findById(final int id, final int data) {
-            final Map<Integer, ObjectType> types = TYPES.get(id);
+            final Int2ObjectMap<ObjectType> types = TYPES.get(id);
             if (types == null) {
                 return null;
             }

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

@@ -22,8 +22,8 @@
  */
 package com.viaversion.viaversion.api.minecraft.entities;
 
-import java.util.HashMap;
-import java.util.Map;
+import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
+import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
 
 public class EntityTypes1_9 {
 
@@ -142,7 +142,7 @@ public class EntityTypes1_9 {
         SPIDER(52, ABSTRACT_MONSTER),
         CAVE_SPIDER(59, SPIDER);
 
-        private static final Map<Integer, EntityType> TYPES = new HashMap<>();
+        private static final Int2ObjectMap<EntityType> TYPES;
 
         private final int id;
         private final EntityType parent;
@@ -183,7 +183,9 @@ public class EntityTypes1_9 {
         }
 
         static {
-            for (EntityType type : EntityType.values()) {
+            final EntityType[] values = EntityType.values();
+            TYPES = new Int2ObjectOpenHashMap<>(values.length);
+            for (EntityType type : values) {
                 TYPES.put(type.id, type);
             }
         }
@@ -229,7 +231,7 @@ public class EntityTypes1_9 {
         SPECTRAL_ARROW(91, EntityType.SPECTRAL_ARROW),
         DRAGON_FIREBALL(93, EntityType.DRAGON_FIREBALL);
 
-        private static final Map<Integer, Map<Integer, ObjectType>> TYPES = new HashMap<>();
+        private static final Int2ObjectMap<Int2ObjectMap<ObjectType>> TYPES = new Int2ObjectOpenHashMap<>();
 
         private final int id;
         private final int data;
@@ -237,7 +239,7 @@ public class EntityTypes1_9 {
 
         static {
             for (ObjectType type : ObjectType.values()) {
-                TYPES.computeIfAbsent(type.id, k -> new HashMap<>()).put(type.data, type);
+                TYPES.computeIfAbsent(type.id, k -> new Int2ObjectOpenHashMap<>()).put(type.data, type);
             }
         }
 
@@ -267,7 +269,7 @@ public class EntityTypes1_9 {
         }
 
         public static ObjectType findById(final int id, final int data) {
-            final Map<Integer, ObjectType> types = TYPES.get(id);
+            final Int2ObjectMap<ObjectType> types = TYPES.get(id);
             if (types == null) {
                 return null;
             }

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

@@ -23,12 +23,9 @@
 package com.viaversion.viaversion.api.minecraft.entitydata.types;
 
 import com.viaversion.viaversion.api.minecraft.PaintingVariant;
-import com.viaversion.viaversion.api.minecraft.Particle;
 import com.viaversion.viaversion.api.minecraft.entitydata.EntityDataType;
-import com.viaversion.viaversion.api.minecraft.item.Item;
-import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
-import com.viaversion.viaversion.api.type.types.misc.ParticleType;
+import com.viaversion.viaversion.api.type.types.version.VersionedTypesHolder;
 
 public final class EntityDataTypes1_21_5 extends AbstractEntityDataTypes {
 
@@ -68,10 +65,10 @@ public final class EntityDataTypes1_21_5 extends AbstractEntityDataTypes {
     public final EntityDataType vector3FType = add(33, Types.VECTOR3F);
     public final EntityDataType quaternionType = add(34, Types.QUATERNION);
 
-    public EntityDataTypes1_21_5(final Type<Item> itemType, final ParticleType particleType, final Type<Particle[]> particlesType) {
+    public EntityDataTypes1_21_5(final VersionedTypesHolder types) {
         super(35);
-        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_9.java

@@ -0,0 +1,76 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.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_9 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 particleType;
+    public final EntityDataType particlesType;
+    public final EntityDataType villagerDatatType = add(18, Types.VILLAGER_DATA);
+    public final EntityDataType optionalVarIntType = add(19, Types.OPTIONAL_VAR_INT);
+    public final EntityDataType poseType = add(20, Types.VAR_INT);
+    public final EntityDataType catVariantType = add(21, Types.VAR_INT);
+    public final EntityDataType cowVariantType = add(22, Types.VAR_INT);
+    public final EntityDataType wolfVariantType = add(23, Types.VAR_INT);
+    public final EntityDataType wolfSoundVariantType = add(24, Types.VAR_INT);
+    public final EntityDataType frogVariantType = add(25, Types.VAR_INT);
+    public final EntityDataType pigVariantType = add(26, Types.VAR_INT);
+    public final EntityDataType chickenVariantType = add(27, Types.VAR_INT);
+    public final EntityDataType optionalGlobalPosition = add(28, Types.OPTIONAL_GLOBAL_POSITION);
+    public final EntityDataType paintingVariantType = add(29, PaintingVariant.TYPE1_21_2);
+    public final EntityDataType snifferState = add(30, Types.VAR_INT);
+    public final EntityDataType armadilloState = add(31, Types.VAR_INT);
+    public final EntityDataType copperGolemState = add(32, Types.VAR_INT);
+    public final EntityDataType weatheringCopperState = add(33, Types.VAR_INT);
+    public final EntityDataType vector3FType = add(34, Types.VECTOR3F);
+    public final EntityDataType quaternionType = add(35, Types.QUATERNION);
+    public final EntityDataType mannequinProfileType = add(36, Types.RESOLVABLE_PROFILE);
+
+    public EntityDataTypes1_21_9(final VersionedTypesHolder types) {
+        super(37);
+        this.itemType = add(7, types.item());
+        this.particleType = add(16, types.particle());
+        this.particlesType = add(17, types.particles());
+    }
+}

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

@@ -39,4 +39,7 @@ public interface HashedItem extends ItemBase {
     Int2IntMap dataHashesById();
 
     IntSet removedDataIds();
+
+    @Override
+    HashedItem copy();
 }

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

@@ -79,6 +79,11 @@ public class HashedStructuredItem implements HashedItem {
         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;

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

@@ -24,10 +24,9 @@ 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 extends ItemBase, Copyable {
+public interface Item extends ItemBase {
 
     /**
      * Returns the item data. Always 0 for 1.13+ items.

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

@@ -22,11 +22,13 @@
  */
 package com.viaversion.viaversion.api.minecraft.item;
 
+import com.viaversion.viaversion.util.Copyable;
+
 /**
  * @see Item
  * @see HashedItem
  */
-public interface ItemBase {
+public interface ItemBase extends Copyable {
 
     /**
      * Returns the item identifier.
@@ -64,4 +66,7 @@ public interface ItemBase {
     default boolean isEmpty() {
         return identifier() == 0 || amount() <= 0;
     }
+
+    @Override
+    ItemBase copy();
 }

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

@@ -22,14 +22,17 @@
  */
 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) implements Copyable {
+public record AdventureModePredicate(BlockPredicate[] predicates,
+                                     boolean showInTooltip) implements Copyable, Rewritable {
 
     public AdventureModePredicate(final BlockPredicate[] predicates) {
         this(predicates, true);
@@ -70,16 +73,17 @@ public record AdventureModePredicate(BlockPredicate[] predicates, boolean showIn
         }
     }
 
-    public AdventureModePredicate rewrite(final Int2IntFunction blockIdRewriter) {
+    @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(copy(predicates), showInTooltip);
+        return new AdventureModePredicate(Copyable.copy(predicates), showInTooltip);
     }
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/ArmorTrim.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.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);
@@ -96,15 +99,16 @@ public record ArmorTrim(Holder<ArmorTrimMaterial> material, Holder<ArmorTrimPatt
         }
     };
 
-    public ArmorTrim rewrite(final Int2IntFunction idRewriteFunction) {
+    @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

@@ -23,16 +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.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) implements Copyable {
+                                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);
@@ -175,8 +178,9 @@ public record ArmorTrimMaterial(String assetName, int itemId, float itemModelInd
         }
     };
 
-    public ArmorTrimMaterial rewrite(final Int2IntFunction idRewriteFunction) {
-        return new ArmorTrimMaterial(assetName, idRewriteFunction.applyAsInt(itemId), itemModelIndex, overrideArmorMaterials, description);
+    @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

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

@@ -23,13 +23,15 @@
 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) implements Copyable {
+public record ArmorTrimPattern(String assetName, int itemId, Tag description, boolean decal) implements Copyable, Rewritable {
 
     public ArmorTrimPattern(final String assetName, final Tag description, final boolean decal) {
         this(assetName, 0, description, decal);
@@ -70,8 +72,9 @@ public record ArmorTrimPattern(String assetName, int itemId, Tag description, bo
         }
     };
 
-    public ArmorTrimPattern rewrite(final Int2IntFunction idRewriteFunction) {
-        return new ArmorTrimPattern(assetName, idRewriteFunction.applyAsInt(itemId), description, decal);
+    @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

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

@@ -22,14 +22,21 @@
  */
 package com.viaversion.viaversion.api.minecraft.item.data;
 
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.data.FullMappings;
+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 java.util.ArrayList;
+import java.util.List;
 import java.util.UUID;
 
-public record AttributeModifiers1_20_5(AttributeModifier[] modifiers, boolean showInTooltip) implements Copyable {
+public record AttributeModifiers1_20_5(AttributeModifier[] modifiers,
+                                       boolean showInTooltip) implements Copyable, Rewritable {
 
     public static final Type<AttributeModifiers1_20_5> TYPE = new Type<>(AttributeModifiers1_20_5.class) {
         @Override
@@ -48,7 +55,24 @@ public record AttributeModifiers1_20_5(AttributeModifier[] modifiers, boolean sh
 
     @Override
     public AttributeModifiers1_20_5 copy() {
-        return new AttributeModifiers1_20_5(copy(modifiers), showInTooltip);
+        return new AttributeModifiers1_20_5(Copyable.copy(modifiers), showInTooltip);
+    }
+
+    @Override
+    public AttributeModifiers1_20_5 rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+        final FullMappings mappings = protocol.getMappingData().getAttributeMappings();
+        if (mappings == null) {
+            return this;
+        }
+
+        final List<AttributeModifier> modifiers = new ArrayList<>(this.modifiers.length);
+        for (final AttributeModifier modifier : this.modifiers) {
+            final int mappedId = clientbound ? mappings.getNewId(modifier.attribute()) : mappings.inverse().getNewId(modifier.attribute());
+            if (mappedId != -1) {
+                modifiers.add(new AttributeModifier(mappedId, modifier.modifier(), modifier.slotType()));
+            }
+        }
+        return new AttributeModifiers1_20_5(modifiers.toArray(AttributeModifier[]::new), this.showInTooltip);
     }
 
     public record AttributeModifier(int attribute, ModifierData modifier, int slotType) {

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

@@ -22,14 +22,23 @@
  */
 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.data.FullMappings;
+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.api.type.types.ArrayType;
 import com.viaversion.viaversion.util.Copyable;
+import com.viaversion.viaversion.util.Key;
+import com.viaversion.viaversion.util.Rewritable;
 import io.netty.buffer.ByteBuf;
 import it.unimi.dsi.fastutil.ints.Int2IntFunction;
+import java.util.ArrayList;
+import java.util.List;
 
-public record AttributeModifiers1_21(AttributeModifier[] modifiers, boolean showInTooltip) implements Copyable {
+public record AttributeModifiers1_21(AttributeModifier[] modifiers, boolean showInTooltip) implements Copyable, Rewritable {
 
     public AttributeModifiers1_21(final AttributeModifier[] modifiers) {
         this(modifiers, true);
@@ -38,27 +47,49 @@ public record AttributeModifiers1_21(AttributeModifier[] modifiers, boolean show
     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_TYPE.read(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_TYPE.write(buffer, value.modifiers());
+            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);
         }
     };
 
@@ -66,19 +97,42 @@ public record AttributeModifiers1_21(AttributeModifier[] modifiers, boolean show
         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);
     }
 
     @Override
     public AttributeModifiers1_21 copy() {
-        return new AttributeModifiers1_21(copy(modifiers), showInTooltip);
+        return new AttributeModifiers1_21(Copyable.copy(modifiers), showInTooltip);
     }
 
-    public record AttributeModifier(int attribute, ModifierData modifier, int slotType) {
+    @Override
+    public AttributeModifiers1_21 rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+        final FullMappings mappings = protocol.getMappingData().getAttributeMappings();
+        if (mappings == null) {
+            return this;
+        }
 
-        public static final Type<AttributeModifier> TYPE = new Type<>(AttributeModifier.class) {
+        final List<AttributeModifier> modifiers = new ArrayList<>(this.modifiers.length);
+        for (final AttributeModifier modifier : this.modifiers) {
+            final int mappedId = clientbound ? mappings.getNewId(modifier.attribute()) : mappings.inverse().getNewId(modifier.attribute());
+            if (mappedId != -1) {
+                modifiers.add(new AttributeModifier(mappedId, modifier.modifier(), modifier.slotType(), modifier.display()));
+            }
+        }
+        return new AttributeModifiers1_21(modifiers.toArray(AttributeModifier[]::new), this.showInTooltip);
+    }
+
+    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);
@@ -93,8 +147,62 @@ 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.TEXT_COMPONENT_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) {
@@ -116,4 +224,52 @@ 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

@@ -23,31 +23,70 @@
 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) implements Copyable {
+public record Bee(EntityData entityData, int ticksInHive, int minTicksInHive) implements Copyable {
 
-    public static final Type<Bee> TYPE = new Type<>(Bee.class) {
+    public Bee(final CompoundTag entityData, final int ticksInHive, final int minTicksInHive) {
+        this(new EntityData(-1, entityData), ticksInHive, minTicksInHive);
+    }
+
+    public static final Type<Bee> TYPE1_20_5 = new Type<>(Bee.class) {
         @Override
         public Bee read(final ByteBuf buffer) {
             final CompoundTag entityData = Types.COMPOUND_TAG.read(buffer);
             final int ticksInHive = Types.VAR_INT.readPrimitive(buffer);
             final int minTicksInHive = Types.VAR_INT.readPrimitive(buffer);
+            return new Bee(new EntityData(-1, entityData), ticksInHive, minTicksInHive);
+        }
+
+        @Override
+        public void write(final ByteBuf buffer, final Bee value) {
+            Types.COMPOUND_TAG.write(buffer, value.entityData.tag());
+            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.tag(), 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_TYPE1_20_5 = new ArrayType<>(TYPE1_20_5);
+
+    public static final Type<Bee> TYPE1_21_9 = new Type<>(Bee.class) {
+        @Override
+        public Bee read(final ByteBuf buffer) {
+            final EntityData entityData = EntityData.TYPE.read(buffer);
+            final int ticksInHive = Types.VAR_INT.readPrimitive(buffer);
+            final int minTicksInHive = Types.VAR_INT.readPrimitive(buffer);
             return new Bee(entityData, ticksInHive, minTicksInHive);
         }
 
         @Override
         public void write(final ByteBuf buffer, final Bee value) {
-            Types.COMPOUND_TAG.write(buffer, value.entityData);
+            EntityData.TYPE.write(buffer, value.entityData);
             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
+                .write("entity_data", EntityData.TYPE, value.entityData)
+                .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);
+    public static final Type<Bee[]> ARRAY_TYPE1_21_9 = new ArrayType<>(TYPE1_21_9);
 
     @Override
     public Bee copy() {

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

@@ -0,0 +1,65 @@
+/*
+ * 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.nbt.tag.CompoundTag;
+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.Rewritable;
+import io.netty.buffer.ByteBuf;
+
+public record BlockEntityData(int type, CompoundTag tag) implements Rewritable {
+
+    public static final Type<BlockEntityData> TYPE = new Type<>(BlockEntityData.class) {
+        @Override
+        public BlockEntityData read(final ByteBuf buffer) {
+            final int type = Types.VAR_INT.readPrimitive(buffer);
+            final CompoundTag tag = Types.COMPOUND_TAG.read(buffer);
+            return new BlockEntityData(type, tag);
+        }
+
+        @Override
+        public void write(final ByteBuf buffer, final BlockEntityData value) {
+            Types.VAR_INT.writePrimitive(buffer, value.type);
+            Types.COMPOUND_TAG.write(buffer, value.tag);
+        }
+
+        @Override
+        public void write(final Ops ops, final BlockEntityData data) {
+            ops.writeMap(map -> map
+                .write("id", Types.RESOURCE_LOCATION, ops.context().registryAccess().blockEntity(data.type))
+                .writeInlinedMap(Types.COMPOUND_TAG, data.tag)
+            );
+        }
+    };
+
+    @Override
+    public BlockEntityData rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+        final int mappedType = protocol.getMappingData().getBlockEntityMappings().getNewId(type);
+        // Empty mappings might be possible for removed block entities, set a dummy value in that case. Will be handled fine by server and client without losing data
+        return new BlockEntityData(mappedType != -1 ? mappedType : 0, tag);
+    }
+}

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

@@ -23,23 +23,27 @@
 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, DataComponentMatchers dataMatchers) implements Copyable {
+                             @Nullable CompoundTag tag,
+                             DataComponentMatchers dataMatchers) implements Copyable, Rewritable {
 
     public BlockPredicate(@Nullable final HolderSet holderSet, final StatePropertyMatcher @Nullable [] propertyMatchers, @Nullable final CompoundTag tag) {
-        this(holderSet, propertyMatchers, tag, null);
+        this(holderSet, propertyMatchers, tag, new DataComponentMatchers(new StructuredData[0], new DataComponentPredicate[0]));
     }
 
     public static final Type<BlockPredicate> TYPE1_20_5 = new Type<>(BlockPredicate.class) {
@@ -96,17 +100,18 @@ public record BlockPredicate(@Nullable HolderSet holderSet, StatePropertyMatcher
         }
     }
 
-    public BlockPredicate rewrite(final Int2IntFunction blockIdRewriter) {
+    @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, copy(propertyMatchers), tag == null ? null : tag.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

@@ -22,6 +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 com.viaversion.viaversion.util.Copyable;
@@ -50,6 +51,15 @@ public record BlockStateProperties(Map<String, String> properties) implements Co
                 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

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/BlocksAttacks.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.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.api.type.types.ArrayType;
+import com.viaversion.viaversion.util.Rewritable;
 import io.netty.buffer.ByteBuf;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
@@ -39,7 +42,7 @@ public record BlocksAttacks(
     @Nullable String bypassedByTag,
     @Nullable Holder<SoundEvent> blockSound,
     @Nullable Holder<SoundEvent> disableSound
-) {
+) implements Rewritable {
 
     public static final Type<BlocksAttacks> TYPE = new Type<>(BlocksAttacks.class) {
 
@@ -67,6 +70,13 @@ public record BlocksAttacks(
         }
     };
 
+    @Override
+    public BlocksAttacks rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+        final Holder<SoundEvent> blockSound = SoundEvent.rewriteHolder(this.blockSound, Rewritable.soundRewriteFunction(protocol, clientbound));
+        final Holder<SoundEvent> disableSound = SoundEvent.rewriteHolder(this.disableSound, Rewritable.soundRewriteFunction(protocol, clientbound));
+        return new BlocksAttacks(this.blockDelaySeconds, this.disableCooldownScale, this.damageReductions, this.itemDamage, this.bypassedByTag, blockSound, disableSound);
+    }
+
     public record DamageReduction(float horizontalBlockingAngle, @Nullable HolderSet type, float base, float factor) {
 
         public static final Type<DamageReduction> TYPE = new Type<>(DamageReduction.class) {

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

@@ -22,17 +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;
-import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 
 public record Consumable1_21_2(float consumeSeconds, int animationType, Holder<SoundEvent> sound,
-                               boolean hasConsumeParticles, ConsumeEffect<?>[] consumeEffects) implements Copyable {
+                               boolean hasConsumeParticles,
+                               ConsumeEffect<?>[] consumeEffects) implements Copyable, Rewritable {
 
     public static final Type<?>[] EFFECT_TYPES = {
         ApplyStatusEffects.TYPE,
@@ -111,13 +114,14 @@ public record Consumable1_21_2(float consumeSeconds, int animationType, Holder<S
         };
     }
 
-    public Consumable1_21_2 rewrite(final Int2IntFunction soundIdRewriteFunction) {
-        final Holder<SoundEvent> soundHolder = this.sound.updateId(soundIdRewriteFunction);
+    @Override
+    public Consumable1_21_2 rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+        final Holder<SoundEvent> soundHolder = SoundEvent.rewriteHolder(this.sound, 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, copy(consumeEffects));
+        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 +1,59 @@
+/*
+ * 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.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];
+                    if (item.isEmpty()) {
+                        continue;
+                    }
+
+                    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

@@ -22,12 +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) implements Copyable {
+public record CustomModelData1_21_4(float[] floats, boolean[] booleans, String[] strings,
+                                    int[] colors) implements Copyable {
 
     public static final Type<CustomModelData1_21_4> TYPE = new Type<>(CustomModelData1_21_4.class) {
         @Override
@@ -46,10 +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(copy(floats), copy(booleans), copy(strings), copy(colors));
+        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 +22,19 @@
  */
 package com.viaversion.viaversion.api.minecraft.item.data;
 
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
+import com.viaversion.viaversion.api.type.TransformingType;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
-import io.netty.buffer.ByteBuf;
+import com.viaversion.viaversion.util.Key;
 
-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);
-            return new DamageResistant(typesTagKey);
-        }
+    public static final Type<DamageResistant> TYPE = new TransformingType<>(Types.RESOURCE_LOCATION, DamageResistant.class, DamageResistant::new, DamageResistant::typesTagKey) {
 
         @Override
-        public void write(final ByteBuf buffer, final DamageResistant value) {
-            Types.STRING.write(buffer, value.typesTagKey());
+        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

@@ -44,6 +44,6 @@ public record DeathProtection(ConsumeEffect<?>[] deathEffects) implements Copyab
 
     @Override
     public DeathProtection copy() {
-        return new DeathProtection(copy(deathEffects));
+        return new DeathProtection(Copyable.copy(deathEffects));
     }
 }

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

@@ -0,0 +1,56 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.item.data;
+
+import com.viaversion.nbt.tag.CompoundTag;
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.protocol.Protocol;
+import com.viaversion.viaversion.api.type.TransformingType;
+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;
+
+public record DebugStickState(CompoundTag tag) implements Rewritable, Copyable {
+
+    public static final Type<DebugStickState> TYPE = TransformingType.of(Types.COMPOUND_TAG, DebugStickState.class, DebugStickState::new, DebugStickState::tag);
+
+    @Override
+    public DebugStickState rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+        CompoundTag updatedTag = tag;
+        if (clientbound && protocol.getMappingData() != null && protocol.getMappingData().changedBlocks() != null) {
+            updatedTag = tag.copy();
+            // Anything beyond this isn't worth the disk space/handling
+            updatedTag.entrySet().removeIf(entry -> {
+                final int blockId = protocol.getMappingData().getFullBlockMappings().id(entry.getKey());
+                return protocol.getMappingData().changedBlocks().contains(blockId);
+            });
+        }
+        return new DebugStickState(updatedTag);
+    }
+
+    @Override
+    public DebugStickState copy() {
+        return new DebugStickState(tag.copy());
+    }
+}

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

@@ -22,7 +22,9 @@
  */
 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) {
@@ -56,5 +58,10 @@ public record DyedColor(int rgb, boolean showInTooltip) {
         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

@@ -22,9 +22,11 @@
  */
 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;
@@ -81,6 +83,16 @@ public record Enchantments(Int2IntMap enchantments, boolean showInTooltip) imple
                 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) {

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

@@ -0,0 +1,70 @@
+/*
+ * 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.nbt.tag.CompoundTag;
+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.Copyable;
+import com.viaversion.viaversion.util.Rewritable;
+import io.netty.buffer.ByteBuf;
+
+public record EntityData(int type, CompoundTag tag) implements Rewritable, Copyable {
+
+    public static final Type<EntityData> TYPE = new Type<>(EntityData.class) {
+        @Override
+        public EntityData read(final ByteBuf buffer) {
+            final int type = Types.VAR_INT.readPrimitive(buffer);
+            final CompoundTag tag = Types.COMPOUND_TAG.read(buffer);
+            return new EntityData(type, tag);
+        }
+
+        @Override
+        public void write(final ByteBuf buffer, final EntityData value) {
+            Types.VAR_INT.writePrimitive(buffer, value.type);
+            Types.COMPOUND_TAG.write(buffer, value.tag);
+        }
+
+        @Override
+        public void write(final Ops ops, final EntityData data) {
+            ops.writeMap(map -> map
+                .write("id", Types.RESOURCE_LOCATION, ops.context().registryAccess().entity(data.type))
+                .writeInlinedMap(Types.COMPOUND_TAG, data.tag)
+            );
+        }
+    };
+
+    @Override
+    public EntityData rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+        final int mappedType = protocol.getMappingData().getEntityMappings().getNewId(type);
+        return new EntityData(mappedType, tag);
+    }
+
+    @Override
+    public EntityData copy() {
+        return new EntityData(type, tag.copy());
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/EnumTypes.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.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");
+    public static final EnumType EQUIPMENT_SLOT = new EnumType("mainhand", "feet", "legs", "chest", "head", "offhand", "body", "saddle");
+    // 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");
+    public static final RegistryValueType POTION = new RegistryValueType("water", "mundane", "thick", "awkward", "night_vision", "long_night_vision", "invisibility", "long_invisibility", "leaping", "long_leaping", "strong_leaping", "fire_resistance", "long_fire_resistance", "swiftness", "long_swiftness", "strong_swiftness", "slowness", "long_slowness", "strong_slowness", "turtle_master", "long_turtle_master", "strong_turtle_master", "water_breathing", "long_water_breathing", "healing", "strong_healing", "harming", "strong_harming", "poison", "long_poison", "strong_poison", "regeneration", "long_regeneration", "strong_regeneration", "strength", "long_strength", "strong_strength", "weakness", "long_weakness", "luck", "slow_falling", "long_slow_falling", "wind_charged", "weaving", "oozing", "infested");
+    public static final RegistryValueType MOB_EFFECT = new RegistryValueType("speed", "slowness", "haste", "mining_fatigue", "strength", "instant_health", "instant_damage", "jump_boost", "nausea", "regeneration", "resistance", "fire_resistance", "water_breathing", "invisibility", "blindness", "night_vision", "hunger", "weakness", "poison", "wither", "health_boost", "absorption", "saturation", "glowing", "levitation", "luck", "unluck", "slow_falling", "conduit_power", "dolphins_grace", "bad_omen", "hero_of_the_village", "darkness", "trial_omen", "raid_omen", "wind_charged", "weaving", "oozing", "infested");
+}

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

@@ -22,24 +22,36 @@
  */
 package com.viaversion.viaversion.api.minecraft.item.data;
 
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.data.MappingData;
 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.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.api.type.types.misc.HolderSetType;
+import com.viaversion.viaversion.util.Key;
+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 equipOnInteract) {
+                         boolean swappable, boolean damageOnHurt, boolean equipOnInteract,
+                         boolean canBeSheared, Holder<SoundEvent> shearingSound) implements Rewritable {
 
     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) {
@@ -93,10 +105,79 @@ public record Equippable(int equipmentSlot, Holder<SoundEvent> soundEvent, @Null
             buffer.writeBoolean(value.damageOnHurt());
             buffer.writeBoolean(value.equipOnInteract());
         }
+
+        @Override
+        public void write(final Ops ops, final Equippable value) {
+            final Holder<SoundEvent> defaultEquipSound = Holder.of(ops.context().registryAccess().id(MappingData.MappingType.SOUND, "item.armor.equip_generic"));
+            ops.writeMap(map -> map
+                .write("slot", EnumTypes.EQUIPMENT_SLOT, value.equipmentSlot)
+                .writeOptional("equip_sound", Types.SOUND_EVENT, value.soundEvent, defaultEquipSound)
+                .writeOptional("asset_id", Types.RESOURCE_LOCATION, value.model != null ? Key.of(value.model) : null)
+                .writeOptional("camera_overlay", Types.RESOURCE_LOCATION, value.cameraOverlay != null ? Key.of(value.cameraOverlay) : null)
+                .writeOptional("allowed_entities", new HolderSetType(MappingData.MappingType.ENTITY), value.allowedEntities)
+                .writeOptional("dispensable", Types.BOOLEAN, value.dispensable, true)
+                .writeOptional("swappable", Types.BOOLEAN, value.swappable, true)
+                .writeOptional("damage_on_hurt", Types.BOOLEAN, value.damageOnHurt, true)
+                .writeOptional("equip_on_interact", Types.BOOLEAN, value.equipOnInteract, false));
+        }
+    };
+    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 void write(final Ops ops, final Equippable value) {
+            final Holder<SoundEvent> defaultSound = Holder.of(ops.context().registryAccess().id(MappingData.MappingType.SOUND, "item.armor.equip_generic"));
+            final Holder<SoundEvent> defaultShearingSound = Holder.of(ops.context().registryAccess().id(MappingData.MappingType.SOUND, "item.shears.snip"));
+            ops.writeMap(map -> map
+                .write("slot", EnumTypes.EQUIPMENT_SLOT, value.equipmentSlot)
+                .writeOptional("equip_sound", Types.SOUND_EVENT, value.soundEvent, defaultSound)
+                .writeOptional("asset_id", Types.RESOURCE_LOCATION, value.model != null ? Key.of(value.model) : null)
+                .writeOptional("camera_overlay", Types.RESOURCE_LOCATION, value.cameraOverlay != null ? Key.of(value.cameraOverlay) : null)
+                .writeOptional("allowed_entities", new HolderSetType(MappingData.MappingType.ENTITY), value.allowedEntities)
+                .writeOptional("dispensable", Types.BOOLEAN, value.dispensable, true)
+                .writeOptional("swappable", Types.BOOLEAN, value.swappable, true)
+                .writeOptional("damage_on_hurt", Types.BOOLEAN, value.damageOnHurt, true)
+                .writeOptional("equip_on_interact", Types.BOOLEAN, value.equipOnInteract, false)
+                .writeOptional("can_be_sheared", Types.BOOLEAN, value.canBeSheared, false)
+                .writeOptional("shearing_sound", Types.SOUND_EVENT, value.shearingSound, defaultShearingSound));
+        }
     };
 
-    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, equipOnInteract);
+    @Override
+    public Equippable rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+        final Holder<SoundEvent> soundEvent = SoundEvent.rewriteHolder(this.soundEvent, Rewritable.soundRewriteFunction(protocol, clientbound));
+        final Holder<SoundEvent> shearingSound = SoundEvent.rewriteHolder(this.shearingSound, Rewritable.soundRewriteFunction(protocol, clientbound));
+        final HolderSet allowedEntities = this.allowedEntities != null ? this.allowedEntities.rewrite(Rewritable.entityRewriteFunction(protocol, clientbound)) : null;
+        return soundEvent == this.soundEvent && shearingSound == this.shearingSound && allowedEntities == this.allowedEntities ? 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

@@ -22,13 +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) implements Copyable {
+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) {
@@ -48,11 +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, copy(colors), copy(fadeColors), hasTrail, hasTwinkle);
+        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

@@ -22,6 +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 com.viaversion.viaversion.util.Copyable;
@@ -42,10 +43,17 @@ public record Fireworks(int flightDuration, FireworkExplosion[] explosions) impl
             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, copy(explosions));
+        return new Fireworks(flightDuration, Copyable.copy(explosions));
     }
 }