5.5.1 Release

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

.github/workflows/build.yml

@@ -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

.github/workflows/publish.yml

@@ -12,19 +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/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
@@ -485,4 +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

@@ -139,17 +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.
@@ -204,9 +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.
@@ -219,6 +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.
@@ -180,6 +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/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/GameProfile.java

@@ -29,7 +29,11 @@ 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]);

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

@@ -24,6 +24,7 @@ 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> {
 
@@ -89,7 +90,18 @@ 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.

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/IdHolder.java

@@ -25,6 +25,7 @@ package com.viaversion.viaversion.api.minecraft;
 import com.google.common.base.Preconditions;
 import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 import java.util.function.Function;
+import java.util.function.Supplier;
 
 record IdHolder<T>(int id) implements Holder<T> {
 
@@ -48,12 +49,15 @@ 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);

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

@@ -24,6 +24,7 @@ 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> {
 
@@ -43,7 +44,7 @@ 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;
     }
 

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

@@ -45,6 +45,16 @@ public interface CodecContext {
 
         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);
         }

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

@@ -129,5 +129,7 @@ public interface Ops {
         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

@@ -66,6 +66,32 @@ final class RegistryAccessImpl implements CodecContext.RegistryAccess {
         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);

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/data/FilledStructuredData.java

@@ -23,6 +23,7 @@
 package com.viaversion.viaversion.api.minecraft.data;
 
 import com.google.common.base.Preconditions;
+import com.viaversion.viaversion.util.ArrayUtil;
 import com.viaversion.viaversion.util.Copyable;
 import io.netty.buffer.ByteBuf;
 import java.util.Objects;
@@ -102,7 +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) {

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

@@ -27,8 +27,8 @@ 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.data.version.StructuredDataKeys1_20_5;
 import com.viaversion.viaversion.api.minecraft.data.version.StructuredDataKeys1_21_2;
@@ -39,12 +39,14 @@ import com.viaversion.viaversion.api.minecraft.item.data.AttributeModifiers1_20_
 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;
@@ -56,15 +58,19 @@ 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;
@@ -95,10 +101,10 @@ 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<Key> ITEM_MODEL = new StructuredDataKey<>("item_model", Types.RESOURCE_LOCATION);
-    public static final StructuredDataKey<Tag[]> LORE = new StructuredDataKey<>("lore", new ArrayType<>(Types.TAG, 256));
+    public static final StructuredDataKey<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);
@@ -132,7 +138,7 @@ public record StructuredDataKey<T>(String identifier, Type<T> type) {
     public static final StructuredDataKey<Equippable> EQUIPPABLE1_21_2 = new StructuredDataKey<>("equippable", Equippable.TYPE1_21_2);
     public static final StructuredDataKey<Equippable> EQUIPPABLE1_21_5 = new StructuredDataKey<>("equippable", Equippable.TYPE1_21_5);
     public static final StructuredDataKey<Equippable> EQUIPPABLE1_21_6 = new StructuredDataKey<>("equippable", Equippable.TYPE1_21_6);
-    public static final StructuredDataKey<HolderSet> REPAIRABLE = new StructuredDataKey<>("repairable", Types.HOLDER_SET);
+    public static final StructuredDataKey<Repairable> REPAIRABLE = new StructuredDataKey<>("repairable", Repairable.TYPE);
     public static final StructuredDataKey<Unit> GLIDER = new StructuredDataKey<>("glider", Types.EMPTY);
     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);
@@ -155,10 +161,12 @@ public record StructuredDataKey<T>(String identifier, Type<T> type) {
     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);
@@ -171,14 +179,17 @@ public record StructuredDataKey<T>(String identifier, Type<T> type) {
     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<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", EnumTypes.DYE_COLOR);
     public static final StructuredDataKey<PotDecorations> POT_DECORATIONS = new StructuredDataKey<>("pot_decorations", PotDecorations.TYPE);
     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);
 
@@ -214,6 +225,7 @@ public record StructuredDataKey<T>(String identifier, Type<T> type) {
     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/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_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_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/Item.java

@@ -24,7 +24,6 @@ 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 {

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
@@ -51,6 +58,23 @@ public record AttributeModifiers1_20_5(AttributeModifier[] modifiers, boolean sh
         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) {
 
         public static final Type<AttributeModifier> TYPE = new Type<>(AttributeModifier.class) {

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

@@ -23,16 +23,22 @@
 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);
@@ -101,6 +107,23 @@ public record AttributeModifiers1_21(AttributeModifier[] modifiers, boolean show
         return new AttributeModifiers1_21(Copyable.copy(modifiers), showInTooltip);
     }
 
+    @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;
+        }
+
+        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"};
@@ -173,7 +196,7 @@ public record AttributeModifiers1_21(AttributeModifier[] modifiers, boolean show
                     map.writeMap("display", display -> {
                         display.write("type", Types.STRING, Display.DISPLAY_TYPES[value.display.id()]);
                         if (value.display instanceof final OverrideText overrideText) {
-                            display.write("value", Types.TAG, overrideText.component);
+                            display.write("value", Types.TEXT_COMPONENT_TAG, overrideText.component);
                         }
                     });
                 });

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

@@ -30,20 +30,24 @@ 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(entityData, ticksInHive, minTicksInHive);
+            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);
+            Types.COMPOUND_TAG.write(buffer, value.entityData.tag());
             Types.VAR_INT.writePrimitive(buffer, value.ticksInHive);
             Types.VAR_INT.writePrimitive(buffer, value.minTicksInHive);
         }
@@ -51,12 +55,38 @@ public record Bee(CompoundTag entityData, int ticksInHive, int minTicksInHive) i
         @Override
         public void write(final Ops ops, final Bee value) {
             ops.writeMap(map -> map
-                .writeOptional("entity_data", Types.COMPOUND_TAG, value.entityData, new CompoundTag())
+                .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_TYPE = new ArrayType<>(TYPE);
+    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) {
+            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_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/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

@@ -116,7 +116,7 @@ public record Consumable1_21_2(float consumeSeconds, int animationType, Holder<S
 
     @Override
     public Consumable1_21_2 rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
-        final Holder<SoundEvent> soundHolder = this.sound.updateId(Rewritable.soundRewriteFunction(protocol, clientbound));
+        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);
     }
 

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

@@ -44,6 +44,10 @@ public final class ContainterContents {
             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)

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

@@ -23,24 +23,14 @@
 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 com.viaversion.viaversion.util.Key;
-import io.netty.buffer.ByteBuf;
 
 public record DamageResistant(Key typesTagKey) {
 
-    public static final Type<DamageResistant> TYPE = new Type<>(DamageResistant.class) {
-        @Override
-        public DamageResistant read(final ByteBuf buffer) {
-            final Key typesTagKey = Types.RESOURCE_LOCATION.read(buffer);
-            return new DamageResistant(typesTagKey);
-        }
-
-        @Override
-        public void write(final ByteBuf buffer, final DamageResistant value) {
-            Types.RESOURCE_LOCATION.write(buffer, value.typesTagKey());
-        }
+    public static final Type<DamageResistant> TYPE = new TransformingType<>(Types.RESOURCE_LOCATION, DamageResistant.class, DamageResistant::new, DamageResistant::typesTagKey) {
 
         @Override
         public void write(final Ops ops, final DamageResistant value) {

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/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

@@ -44,8 +44,11 @@ public final class EnumTypes {
     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

@@ -23,12 +23,16 @@
 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 org.checkerframework.checker.nullness.qual.Nullable;
@@ -101,6 +105,21 @@ 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
@@ -133,12 +152,32 @@ public record Equippable(int equipmentSlot, Holder<SoundEvent> soundEvent, @Null
             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));
+        }
     };
 
     @Override
     public Equippable rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
-        final Holder<SoundEvent> soundEvent = this.soundEvent.updateId(Rewritable.soundRewriteFunction(protocol, clientbound));
-        final Holder<SoundEvent> shearingSound = this.shearingSound.updateId(Rewritable.soundRewriteFunction(protocol, clientbound));
-        return soundEvent == this.soundEvent && shearingSound == this.shearingSound ? this : new Equippable(equipmentSlot, soundEvent, model, cameraOverlay, allowedEntities, dispensable, swappable, damageOnHurt, equipOnInteract, canBeSheared, shearingSound);
+        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/Instrument1_20_5.java

@@ -52,7 +52,7 @@ public record Instrument1_20_5(Holder<SoundEvent> soundEvent, int useDuration, f
 
     @Override
     public Instrument1_20_5 rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
-        final Holder<SoundEvent> soundEvent = this.soundEvent.updateId(Rewritable.soundRewriteFunction(protocol, clientbound));
+        final Holder<SoundEvent> soundEvent = SoundEvent.rewriteHolder(this.soundEvent, Rewritable.soundRewriteFunction(protocol, clientbound));
         return soundEvent == this.soundEvent ? this : new Instrument1_20_5(soundEvent, useDuration, range);
     }
 }

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

@@ -59,7 +59,7 @@ public record Instrument1_21_2(Holder<SoundEvent> soundEvent, float useDuration,
 
     @Override
     public Instrument1_21_2 rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
-        final Holder<SoundEvent> soundEvent = this.soundEvent.updateId(Rewritable.soundRewriteFunction(protocol, clientbound));
+        final Holder<SoundEvent> soundEvent = SoundEvent.rewriteHolder(this.soundEvent, Rewritable.soundRewriteFunction(protocol, clientbound));
         return soundEvent == this.soundEvent ? this : new Instrument1_21_2(soundEvent, useDuration, range, description);
     }
 

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

@@ -0,0 +1,44 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.item.data;
+
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.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.Key;
+import com.viaversion.viaversion.util.Rewritable;
+
+public record ItemModel(Key key) implements Rewritable {
+
+    public static final Type<ItemModel> TYPE = TransformingType.of(Types.RESOURCE_LOCATION, ItemModel.class, ItemModel::new, ItemModel::key);
+
+    @Override
+    public ItemModel rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+        // This data specifically will often be used with Vanilla items, so the key should be rewritten
+        final String type = key().toString();
+        final String mappedType = Rewritable.rewriteItem(protocol, clientbound, type);
+        return mappedType == null || type.equals(mappedType) ? this : new ItemModel(Key.of(mappedType));
+    }
+}

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

@@ -111,7 +111,7 @@ public record JukeboxPlayable(EitherHolder<JukeboxSong> song, boolean showInTool
 
         @Override
         public JukeboxSong rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
-            final Holder<SoundEvent> soundEvent = this.soundEvent.updateId(Rewritable.soundRewriteFunction(protocol, clientbound));
+            final Holder<SoundEvent> soundEvent = SoundEvent.rewriteHolder(this.soundEvent, Rewritable.soundRewriteFunction(protocol, clientbound));
             return soundEvent == this.soundEvent ? this : new JukeboxSong(soundEvent, description, lengthInSeconds, comparatorOutput);
         }
     }

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

@@ -0,0 +1,85 @@
+/*
+ * 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.nbt.tag.ListTag;
+import com.viaversion.nbt.tag.StringTag;
+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.HolderSet;
+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 LockCode(CompoundTag tag) implements Rewritable, Copyable {
+
+    public static final Type<LockCode> TYPE = TransformingType.of(Types.COMPOUND_TAG, LockCode.class, LockCode::new, LockCode::tag);
+
+    @Override
+    public LockCode rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+        CompoundTag updatedTag = tag;
+        if (clientbound && protocol.getComponentRewriter() != null) {
+            // Just abuse the component rewriter and keep this one-way
+            updatedTag = tag.copy();
+            updatedTag.putString("id", "air");
+            protocol.getComponentRewriter().handleShowItem(connection, updatedTag);
+            updatedTag.remove("id");
+
+            final FullMappings mappings = protocol.getMappingData().getFullItemMappings();
+            final Tag itemsTag = updatedTag.get("items");
+            if (itemsTag != null) {
+                final HolderSet items = HolderSet.fromTag(itemsTag, key -> mappings.id(key));
+                items.rewrite(mappings::getNewId);
+                updatedTag.put("items", toTag(items, mappings));
+            }
+        }
+        return new LockCode(updatedTag);
+    }
+
+    private Tag toTag(final HolderSet holderSet, final FullMappings mappings) {
+        if (holderSet.hasTagKey()) {
+            return new StringTag("#" + holderSet.tagKey());
+        }
+
+        final int[] ids = holderSet.ids();
+        if (ids.length == 1) {
+            return new StringTag(mappings.mappedIdentifier(ids[0]));
+        }
+
+        final ListTag<StringTag> listTag = new ListTag<>(StringTag.class);
+        for (final int id : ids) {
+            listTag.add(new StringTag(mappings.mappedIdentifier(id)));
+        }
+        return listTag;
+    }
+
+    @Override
+    public LockCode copy() {
+        return new LockCode(tag.copy());
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/PotionContents.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;
@@ -85,6 +86,15 @@ public record PotionContents(@Nullable Integer potion, @Nullable Integer customC
             PotionEffect.ARRAY_TYPE.write(buffer, value.customEffects);
             Types.OPTIONAL_STRING.write(buffer, value.customName);
         }
+
+        @Override
+        public void write(final Ops ops, final PotionContents value) {
+            ops.writeMap(map -> map
+                .writeOptional("potion", EnumTypes.POTION, value.potion)
+                .writeOptional("custom_color", Types.INT, value.customColor)
+                .writeOptional("custom_effects", PotionEffect.ARRAY_TYPE, value.customEffects, new PotionEffect[0])
+                .writeOptional("custom_name", Types.STRING, value.customName));
+        }
     };
 
     @Override

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/PotionEffect.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.api.type.types.ArrayType;
@@ -42,6 +43,13 @@ public record PotionEffect(int effect, PotionEffectData effectData) {
             Types.VAR_INT.writePrimitive(buffer, value.effect);
             PotionEffectData.TYPE.write(buffer, value.effectData);
         }
+
+        @Override
+        public void write(final Ops ops, final PotionEffect value) {
+            ops.writeMap(map -> map
+                .write("id", EnumTypes.MOB_EFFECT, value.effect)
+                .writeInlinedMap(PotionEffectData.TYPE, value.effectData));
+        }
     };
     public static final Type<PotionEffect[]> ARRAY_TYPE = new ArrayType<>(TYPE);
 

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/PotionEffectData.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.OptionalType;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
@@ -52,6 +53,17 @@ public record PotionEffectData(int amplifier, int duration, boolean ambient, boo
             buffer.writeBoolean(value.showIcon);
             OPTIONAL_TYPE.write(buffer, value.hiddenEffect);
         }
+
+        @Override
+        public void write(final Ops ops, final PotionEffectData value) {
+            ops.writeMap(map -> map
+                .writeOptional("amplifier", Types.UNSIGNED_BYTE, (short) value.amplifier, (short) 0)
+                .writeOptional("duration", Types.INT, value.duration, 0)
+                .writeOptional("ambient", Types.BOOLEAN, value.ambient, false)
+                .writeOptional("show_particles", Types.BOOLEAN, value.showParticles, true)
+                .writeOptional("show_icon", Types.BOOLEAN, value.showIcon)
+                .writeOptional("hidden_effect", TYPE, value.hiddenEffect));
+        }
     };
     public static final Type<PotionEffectData> OPTIONAL_TYPE = new OptionalType<>(TYPE) {
     };

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

@@ -0,0 +1,50 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.item.data;
+
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.data.MappingData.MappingType;
+import com.viaversion.viaversion.api.minecraft.HolderSet;
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
+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.api.type.types.misc.HolderSetType;
+import com.viaversion.viaversion.util.Rewritable;
+
+public record Repairable(HolderSet items) implements Rewritable {
+
+    public static final Type<Repairable> TYPE = new TransformingType<>(Types.HOLDER_SET, Repairable.class, Repairable::new, Repairable::items) {
+        @Override
+        public void write(final Ops ops, final Repairable value) {
+            ops.writeMap(map -> map.write("items", new HolderSetType(MappingType.ITEM), value.items));
+        }
+    };
+
+    @Override
+    public Repairable rewrite(final UserConnection connection, final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+        final HolderSet items = this.items.rewrite(Rewritable.itemRewriteFunction(protocol, clientbound));
+        return this.items == items ? this : new Repairable(items);
+    }
+}

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

@@ -100,9 +100,9 @@ public abstract class AbstractProtocol<CU extends ClientboundPacketType, CM exte
         Preconditions.checkArgument(!initialized, "Protocol has already been initialized");
         initialized = true;
 
-        // Create logger if protocol does not have one
-        if (getLogger() == null) {
-            logger = new ProtocolLogger(getClass());
+        // Create logger if the protocol doesn't have one
+        if (logger == null) {
+            logger = createLogger();
         }
         registerPackets();
         registerConfigurationChangeHandlers();
@@ -128,6 +128,10 @@ public abstract class AbstractProtocol<CU extends ClientboundPacketType, CM exte
         }
     }
 
+    protected ProtocolLogger createLogger() {
+        return new ProtocolLogger(getClass());
+    }
+
     protected void registerConfigurationChangeHandlers() {
         // Register handlers for protocol state switching
         // Assuming ids will change too often, it is cleaner to register them here instead of the base protocols,
@@ -139,7 +143,7 @@ public abstract class AbstractProtocol<CU extends ClientboundPacketType, CM exte
 
         final CU startConfigurationPacket = startConfigurationPacket();
         if (startConfigurationPacket != null) {
-            appendClientbound(startConfigurationPacket, setServerStateHandler(State.CONFIGURATION));
+            appendClientbound(startConfigurationPacket, startConfigurationHandler());
         }
 
         final SU finishConfigurationPacket = serverboundFinishConfigurationPacket();
@@ -476,6 +480,16 @@ public abstract class AbstractProtocol<CU extends ClientboundPacketType, CM exte
         return wrapper -> wrapper.user().getProtocolInfo().setServerState(state);
     }
 
+    private PacketHandler startConfigurationHandler() {
+        return setServerStateHandler(State.CONFIGURATION).then(wrapper -> {
+            // Mimic client behaviour
+            final EntityTracker tracker = wrapper.user().getEntityTracker(getClass());
+            if (tracker != null) {
+                tracker.clear();
+            }
+        });
+    }
+
     @Override
     public final PacketTypesProvider<CU, CM, SM, SU> getPacketTypesProvider() {
         return packetTypesProvider;

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

@@ -24,11 +24,15 @@ package com.viaversion.viaversion.api.protocol;
 
 import com.viaversion.viaversion.api.connection.UserConnection;
 import com.viaversion.viaversion.api.protocol.packet.Direction;
+import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
+import com.viaversion.viaversion.api.protocol.packet.State;
+import com.viaversion.viaversion.exception.CancelException;
+import com.viaversion.viaversion.exception.InformativeException;
 import java.util.Collection;
 import java.util.List;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
-public interface ProtocolPipeline extends SimpleProtocol {
+public interface ProtocolPipeline {
 
     /**
      * Adds a protocol to the current pipeline.
@@ -67,6 +71,15 @@ public interface ProtocolPipeline extends SimpleProtocol {
     @Deprecated
     @Nullable <P extends Protocol> P getProtocol(Class<P> pipeClass);
 
+    /**
+     * Transform a packet using the protocols in this pipeline.
+     *
+     * @param direction     The direction the packet is going in
+     * @param state         The current protocol state
+     * @param packetWrapper The packet wrapper to transform
+     */
+    void transform(Direction direction, State state, PacketWrapper packetWrapper) throws InformativeException, CancelException;
+
     List<Protocol> pipes(@Nullable Class<? extends Protocol> protocolClass, boolean skipCurrentPipeline, Direction direction);
 
     /**

api/src/main/java/com/viaversion/viaversion/api/protocol/packet/PacketTracker.java

@@ -23,152 +23,219 @@
 package com.viaversion.viaversion.api.protocol.packet;
 
 import com.viaversion.viaversion.api.Via;
+import com.viaversion.viaversion.api.configuration.RateLimitConfig;
 import com.viaversion.viaversion.api.configuration.ViaVersionConfig;
 import com.viaversion.viaversion.api.connection.UserConnection;
+import java.util.Arrays;
 
 public class PacketTracker {
-    private final UserConnection connection;
+    private static final long SECOND_NANOS = 1_000_000_000L;
+
+    private final RateTracker packetTracker = new RateTracker(5);
+    private final RateTracker packetSizeTracker = new RateTracker(3);
+    private long startTime = System.nanoTime();
     private boolean packetLimiterEnabled = true;
-    private long sentPackets;
-    private long receivedPackets;
-    // Used for tracking pps
-    private long startTime;
-    private long intervalPackets;
-    private long packetsPerSecond = -1L;
-    // Used for handling warnings (over time)
-    private int secondsObserved;
-    private int warnings;
+    private final UserConnection connection;
+    private long sentPacketsTotal;
+    private long receivedPacketsTotal;
 
     public PacketTracker(UserConnection connection) {
         this.connection = connection;
     }
 
     /**
-     * Used for incrementing the number of packets sent to the client.
+     * Increments the number of packets sent to the client.
      */
     public void incrementSent() {
-        this.sentPackets++;
+        this.sentPacketsTotal++;
     }
 
-    /**
-     * Used for incrementing the number of packets received from the client.
-     *
-     * @return true if the interval has reset and can now be checked for the packets sent
-     */
+    @Deprecated(forRemoval = true)
     public boolean incrementReceived() {
-        // handle stats
-        long diff = System.currentTimeMillis() - startTime;
-        if (diff >= 1000) {
-            packetsPerSecond = intervalPackets;
-            startTime = System.currentTimeMillis();
-            intervalPackets = 1;
-            return true;
-        } else {
-            intervalPackets++;
-        }
-        // increase total
-        this.receivedPackets++;
-        return false;
+        return incrementReceived(0);
     }
 
     /**
-     * Checks for packet flood with the packets sent in the last second.
-     * ALWAYS check for {@link #incrementReceived()} before using this method.
+     * Increments the number of packets received from the client.
      *
-     * @return true if the packet should be cancelled
-     * @see #incrementReceived()
+     * @return true if the interval has reset
      */
-    public boolean exceedsMaxPPS() {
-        if (connection.isClientSide()) return false; // Don't apply PPS limiting for client-side
-        ViaVersionConfig conf = Via.getConfig();
-        // Max PPS Checker
-        if (conf.getMaxPPS() > 0 && packetsPerSecond >= conf.getMaxPPS()) {
-            connection.disconnect(conf.getMaxPPSKickMessage().replace("%pps", Long.toString(packetsPerSecond)));
-            return true; // don't send current packet
-        }
+    public boolean incrementReceived(int packetSize) {
+        receivedPacketsTotal++;
 
-        // Tracking PPS Checker
-        if (conf.getMaxWarnings() > 0 && conf.getTrackingPeriod() > 0) {
-            if (secondsObserved > conf.getTrackingPeriod()) {
-                // Reset
-                warnings = 0;
-                secondsObserved = 1;
-            } else {
-                secondsObserved++;
-                if (packetsPerSecond >= conf.getWarningPPS()) {
-                    warnings++;
-                }
-
-                if (warnings >= conf.getMaxWarnings()) {
-                    connection.disconnect(conf.getMaxWarningsKickMessage().replace("%pps", Long.toString(packetsPerSecond)));
-                    return true; // don't send current packet
-                }
+        ViaVersionConfig config = Via.getConfig();
+        long currentTime = System.nanoTime();
+        long elapsed = currentTime - startTime;
+        if (elapsed < SECOND_NANOS) {
+            // Add to current interval
+            if (config.getPacketTrackerConfig().enabled()) {
+                packetTracker.addIntervalValue(1);
             }
+            if (config.getPacketSizeTrackerConfig().enabled()) {
+                packetSizeTracker.addIntervalValue(packetSize);
+            }
+            return false;
         }
-        return false;
+
+        // Reset interval tracking
+        if (config.getPacketTrackerConfig().enabled()) {
+            packetTracker.updateRate(elapsed);
+            packetTracker.addIntervalValue(1);
+        }
+        if (config.getPacketSizeTrackerConfig().enabled()) {
+            packetSizeTracker.updateRate(elapsed);
+            packetSizeTracker.addIntervalValue(packetSize);
+        }
+        startTime = currentTime;
+        return true;
+    }
+
+    public boolean exceedsLimits() {
+        if (connection.isClientSide()) {
+            return false;
+        }
+
+        ViaVersionConfig config = Via.getConfig();
+        return packetTracker.exceedsLimit(connection, config.getPacketTrackerConfig())
+            || packetSizeTracker.exceedsLimit(connection, config.getPacketSizeTrackerConfig());
     }
 
     public long getSentPackets() {
-        return sentPackets;
+        return sentPacketsTotal;
     }
 
+    @Deprecated(forRemoval = true)
     public void setSentPackets(long sentPackets) {
-        this.sentPackets = sentPackets;
+        this.sentPacketsTotal = sentPackets;
     }
 
     public long getReceivedPackets() {
-        return receivedPackets;
+        return receivedPacketsTotal;
     }
 
+    @Deprecated(forRemoval = true)
     public void setReceivedPackets(long receivedPackets) {
-        this.receivedPackets = receivedPackets;
-    }
-
-    public long getStartTime() {
-        return startTime;
-    }
-
-    public void setStartTime(long startTime) {
-        this.startTime = startTime;
+        this.receivedPacketsTotal = receivedPackets;
     }
 
+    @Deprecated(forRemoval = true)
     public long getIntervalPackets() {
-        return intervalPackets;
+        return this.packetTracker.intervalValue;
     }
 
+    @Deprecated(forRemoval = true)
     public void setIntervalPackets(long intervalPackets) {
-        this.intervalPackets = intervalPackets;
+        this.packetTracker.intervalValue = Math.toIntExact(intervalPackets);
     }
 
-    public long getPacketsPerSecond() {
-        return packetsPerSecond;
-    }
-
-    public void setPacketsPerSecond(long packetsPerSecond) {
-        this.packetsPerSecond = packetsPerSecond;
-    }
-
-    public int getSecondsObserved() {
-        return secondsObserved;
-    }
-
-    public void setSecondsObserved(int secondsObserved) {
-        this.secondsObserved = secondsObserved;
-    }
-
-    public int getWarnings() {
-        return warnings;
-    }
-
-    public void setWarnings(int warnings) {
-        this.warnings = warnings;
+    public int getPacketsPerSecond() {
+        return packetTracker.currentRate;
     }
 
     public boolean isPacketLimiterEnabled() {
-        return packetLimiterEnabled;
+        ViaVersionConfig config = Via.getConfig();
+        return packetLimiterEnabled && config.getPacketTrackerConfig().enabled() && config.getPacketSizeTrackerConfig().enabled();
     }
 
     public void setPacketLimiterEnabled(boolean packetLimiterEnabled) {
         this.packetLimiterEnabled = packetLimiterEnabled;
     }
+
+    @Deprecated(forRemoval = true)
+    public void setWarnings(int warnings) {
+        this.packetTracker.warnings = warnings;
+    }
+
+    private static final class RateTracker {
+        private final int[] history;
+        private int historyIndex;
+        private int historyCount;
+        private int currentRate = -1;
+
+        // Interval tracking
+        int intervalValue;
+
+        // Warning system
+        private long warningPeriodStart = System.nanoTime();
+        private int warnings;
+
+        public RateTracker(int windowSize) {
+            this.history = new int[windowSize];
+        }
+
+        public void addIntervalValue(int value) {
+            intervalValue += value;
+        }
+
+        public void updateRate(long elapsedNanos) {
+            // Update sliding window
+            history[historyIndex] = (int) ((intervalValue * SECOND_NANOS) / elapsedNanos);
+            historyIndex = (historyIndex + 1) % history.length;
+            if (historyCount < history.length) {
+                historyCount++;
+            }
+
+            // Calculate smoothed average
+            int sum = 0;
+            for (int i = 0; i < historyCount; i++) {
+                sum += history[i];
+            }
+
+            currentRate = sum / historyCount;
+            intervalValue = 0; // Reset
+        }
+
+        public boolean exceedsLimit(UserConnection connection, RateLimitConfig limitConfig) {
+            if (!limitConfig.enabled() || currentRate < 0) {
+                return false;
+            }
+
+            // Immediate limit check
+            if (limitConfig.maxRate() > 0 && currentRate >= limitConfig.maxRate()) {
+                connection.disconnect(limitConfig.maxRateKickMessage().replace(limitConfig.ratePlaceholder(), Integer.toString(currentRate)));
+                return true;
+            }
+
+            // Interval warnings
+            if (limitConfig.maxWarnings() > 0 && limitConfig.trackingPeriodNanos() > 0 && limitConfig.warningRate() > 0) {
+                return checkTrackedInterval(connection, limitConfig);
+            }
+
+            return false;
+        }
+
+        private boolean checkTrackedInterval(UserConnection connection, RateLimitConfig config) {
+            long currentTime = System.nanoTime();
+            if (currentTime - warningPeriodStart >= config.trackingPeriodNanos()) {
+                // Reset
+                warnings = 0;
+                warningPeriodStart = currentTime;
+                return false;
+            }
+
+            if (currentRate >= config.warningRate() && ++warnings >= config.maxWarnings()) {
+                connection.disconnect(config.warningKickMessage().replace(config.ratePlaceholder(), Integer.toString(currentRate)));
+                return true;
+            }
+            return false;
+        }
+
+        public void reset() {
+            intervalValue = 0;
+            currentRate = -1;
+            warnings = 0;
+            warningPeriodStart = System.nanoTime();
+            historyIndex = 0;
+            historyCount = 0;
+            Arrays.fill(history, 0);
+        }
+    }
+
+    public void reset() {
+        sentPacketsTotal = 0;
+        receivedPacketsTotal = 0;
+        startTime = System.nanoTime();
+        packetTracker.reset();
+        packetSizeTracker.reset();
+    }
 }

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

@@ -90,6 +90,8 @@ public class ProtocolVersion implements Comparable<ProtocolVersion> {
     public static final ProtocolVersion v1_21_4 = register(769, "1.21.4");
     public static final ProtocolVersion v1_21_5 = register(770, "1.21.5");
     public static final ProtocolVersion v1_21_6 = register(771, "1.21.6");
+    public static final ProtocolVersion v1_21_7 = register(772, "1.21.7-1.21.8", new SubVersionRange("1.21", 7, 8));
+    public static final ProtocolVersion v1_21_9 = register(773, "1.21.9-1.21.10", new SubVersionRange("1.21", 9, 10));
     public static final ProtocolVersion unknown = new ProtocolVersion(VersionType.SPECIAL, -1, -1, "UNKNOWN", null);
 
     static {

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

@@ -23,6 +23,7 @@
 package com.viaversion.viaversion.api.rewriter;
 
 import com.google.gson.JsonElement;
+import com.viaversion.nbt.tag.CompoundTag;
 import com.viaversion.nbt.tag.Tag;
 import com.viaversion.viaversion.api.connection.UserConnection;
 import org.checkerframework.checker.nullness.qual.Nullable;
@@ -34,4 +35,6 @@ public interface ComponentRewriter {
     void processText(UserConnection connection, @Nullable JsonElement element);
 
     JsonElement processText(UserConnection connection, @Nullable String json);
+
+    void handleShowItem(UserConnection connection, CompoundTag itemTag);
 }

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

@@ -0,0 +1,77 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.type;
+
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
+import io.netty.buffer.ByteBuf;
+import java.util.function.Function;
+
+public class TransformingType<F, T> extends Type<T> {
+    private final Type<F> from;
+    private final Function<F, T> mapFunction;
+    private final Function<T, F> reverseFunction;
+
+    protected TransformingType(
+        final Type<F> from, final Class<T> outputClass,
+        final Function<F, T> mapFunction, final Function<T, F> reverseFunction
+    ) {
+        super(from.getTypeName(), outputClass);
+        this.from = from;
+        this.mapFunction = mapFunction;
+        this.reverseFunction = reverseFunction;
+    }
+
+    /**
+     * Returns a type that transforms the input to a separate output type.
+     * Useful if you have wrapper classes of a single object.
+     *
+     * @param from            type to map from
+     * @param outputClass     output class
+     * @param mapFunction     function to map from F to T
+     * @param reverseFunction function to map from T to F
+     * @param <F>             from type
+     * @param <T>             to type
+     * @return transforming type
+     */
+    public static <F, T> Type<T> of(
+        final Type<F> from, final Class<T> outputClass,
+        final Function<F, T> mapFunction, final Function<T, F> reverseFunction
+    ) {
+        return new TransformingType<>(from, outputClass, mapFunction, reverseFunction);
+    }
+
+    @Override
+    public T read(final ByteBuf buffer) {
+        return mapFunction.apply(from.read(buffer));
+    }
+
+    @Override
+    public void write(final ByteBuf buffer, final T value) {
+        from.write(buffer, reverseFunction.apply(value));
+    }
+
+    @Override
+    public void write(final Ops ops, final T value) {
+        from.write(ops, reverseFunction.apply(value));
+    }
+}

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

@@ -36,8 +36,10 @@ import com.viaversion.viaversion.api.minecraft.PlayerMessageSignature;
 import com.viaversion.viaversion.api.minecraft.ProfileKey;
 import com.viaversion.viaversion.api.minecraft.Quaternion;
 import com.viaversion.viaversion.api.minecraft.RegistryEntry;
+import com.viaversion.viaversion.api.minecraft.ResolvableProfile;
 import com.viaversion.viaversion.api.minecraft.SoundEvent;
 import com.viaversion.viaversion.api.minecraft.Vector;
+import com.viaversion.viaversion.api.minecraft.Vector3d;
 import com.viaversion.viaversion.api.minecraft.Vector3f;
 import com.viaversion.viaversion.api.minecraft.VillagerData;
 import com.viaversion.viaversion.api.minecraft.blockentity.BlockEntity;
@@ -70,6 +72,7 @@ import com.viaversion.viaversion.api.type.types.ShortType;
 import com.viaversion.viaversion.api.type.types.StringType;
 import com.viaversion.viaversion.api.type.types.UUIDType;
 import com.viaversion.viaversion.api.type.types.UnsignedByteType;
+import com.viaversion.viaversion.api.type.types.UnsignedIntType;
 import com.viaversion.viaversion.api.type.types.UnsignedShortType;
 import com.viaversion.viaversion.api.type.types.VarIntArrayType;
 import com.viaversion.viaversion.api.type.types.VarIntType;
@@ -100,6 +103,7 @@ import com.viaversion.viaversion.api.type.types.math.BlockPositionType1_8;
 import com.viaversion.viaversion.api.type.types.math.ChunkPositionType;
 import com.viaversion.viaversion.api.type.types.math.EulerAngleType;
 import com.viaversion.viaversion.api.type.types.math.GlobalBlockPositionType;
+import com.viaversion.viaversion.api.type.types.math.MovementVectorType;
 import com.viaversion.viaversion.api.type.types.math.QuaternionType;
 import com.viaversion.viaversion.api.type.types.math.Vector3fType;
 import com.viaversion.viaversion.api.type.types.math.VectorType;
@@ -108,13 +112,16 @@ import com.viaversion.viaversion.api.type.types.misc.GameProfileType;
 import com.viaversion.viaversion.api.type.types.misc.HolderSetType;
 import com.viaversion.viaversion.api.type.types.misc.HolderType;
 import com.viaversion.viaversion.api.type.types.misc.KeyType;
+import com.viaversion.viaversion.api.type.types.misc.LengthPrefixedTagType;
 import com.viaversion.viaversion.api.type.types.misc.NamedCompoundTagType;
 import com.viaversion.viaversion.api.type.types.misc.PlayerMessageSignatureType;
 import com.viaversion.viaversion.api.type.types.misc.ProfileKeyType;
 import com.viaversion.viaversion.api.type.types.misc.ProfilePropertyType;
 import com.viaversion.viaversion.api.type.types.misc.SoundEventType;
+import com.viaversion.viaversion.api.type.types.misc.ResolvableProfileType;
 import com.viaversion.viaversion.api.type.types.misc.TagKeyType;
 import com.viaversion.viaversion.api.type.types.misc.TagType;
+import com.viaversion.viaversion.api.type.types.misc.TextComponentTagType;
 import com.viaversion.viaversion.api.type.types.misc.VillagerDataType;
 import com.viaversion.viaversion.api.type.types.version.Types1_20_5;
 import com.viaversion.viaversion.util.Key;
@@ -142,6 +149,7 @@ public final class Types {
 
     public static final IntType INT = new IntType();
     public static final Type<int[]> INT_ARRAY_PRIMITIVE = new IntArrayType();
+    public static final UnsignedIntType UNSIGNED_INT = new UnsignedIntType();
 
     public static final FloatType FLOAT = new FloatType();
     public static final FloatType.OptionalFloatType OPTIONAL_FLOAT = new FloatType.OptionalFloatType();
@@ -190,6 +198,7 @@ public final class Types {
     public static final Type<Vector> VECTOR = new VectorType();
     public static final Type<Vector3f> VECTOR3F = new Vector3fType();
     public static final Type<Quaternion> QUATERNION = new QuaternionType();
+    public static final Type<Vector3d> MOVEMENT_VECTOR = new MovementVectorType();
 
     public static final Type<CompoundTag> NAMED_COMPOUND_TAG = new NamedCompoundTagType();
     public static final Type<CompoundTag> OPTIONAL_NAMED_COMPOUND_TAG = new NamedCompoundTagType.OptionalNamedCompoundTagType();
@@ -199,6 +208,8 @@ public final class Types {
     public static final Type<Tag> TAG = new TagType();
     public static final Type<Tag[]> TAG_ARRAY = new ArrayType<>(TAG);
     public static final Type<Tag> OPTIONAL_TAG = new TagType.OptionalTagType();
+    public static final Type<Tag> TEXT_COMPONENT_TAG = new TextComponentTagType(); // only strictly needed for hashing
+    public static final Type<Tag> CUSTOM_CLICK_ACTION_TAG = new LengthPrefixedTagType(65536);
 
     public static final Type<GlobalBlockPosition> GLOBAL_POSITION = new GlobalBlockPositionType();
     public static final Type<GlobalBlockPosition> OPTIONAL_GLOBAL_POSITION = new GlobalBlockPositionType.OptionalGlobalPositionType();
@@ -220,6 +231,7 @@ public final class Types {
     public static final Type<VillagerData> VILLAGER_DATA = new VillagerDataType();
 
     public static final Type<GameProfile> GAME_PROFILE = new GameProfileType();
+    public static final Type<ResolvableProfile> RESOLVABLE_PROFILE = new ResolvableProfileType();
     public static final Type<GameProfile.Property> PROFILE_PROPERTY = new ProfilePropertyType();
     public static final Type<GameProfile.Property[]> PROFILE_PROPERTY_ARRAY = new ArrayType<>(PROFILE_PROPERTY);
     public static final Type<ProfileKey> PROFILE_KEY = new ProfileKeyType();

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

@@ -41,4 +41,8 @@ public final class RegistryValueType extends VarIntType {
     public void write(final Ops ops, final Integer value) {
         Types.STRING.write(ops, names[value]);
     }
+
+    public String[] names() {
+        return names;
+    }
 }

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

@@ -0,0 +1,63 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.type.types;
+
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.TypeConverter;
+import io.netty.buffer.ByteBuf;
+
+public class UnsignedIntType extends Type<Long> implements TypeConverter<Long> {
+    public static final long MAX_UNSIGNED_INT = 0xFFFFFFFFL;
+
+    public UnsignedIntType() {
+        super(Long.class);
+    }
+
+    @Override
+    public Long read(ByteBuf buffer) {
+        return buffer.readUnsignedInt();
+    }
+
+    public long readPrimitive(ByteBuf buffer) {
+        return buffer.readUnsignedInt();
+    }
+
+    @Override
+    public void write(ByteBuf buffer, Long l) {
+        buffer.writeInt(l.intValue());
+    }
+
+    public void writePrimitive(ByteBuf buffer, long l) {
+        buffer.writeInt((int) l);
+    }
+
+    @Override
+    public Long from(Object o) {
+        if (o instanceof Number number) {
+            return number.longValue();
+        } else if (o instanceof Boolean boo) {
+            return boo ? 1L : 0L;
+        }
+        throw new UnsupportedOperationException();
+    }
+}

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

@@ -25,7 +25,6 @@ package com.viaversion.viaversion.api.type.types.chunk;
 import com.viaversion.viaversion.api.minecraft.chunks.Chunk;
 import com.viaversion.viaversion.api.minecraft.chunks.ChunkSection;
 import com.viaversion.viaversion.api.minecraft.chunks.ChunkSectionImpl;
-import com.viaversion.viaversion.api.minecraft.chunks.DataPalette;
 import com.viaversion.viaversion.api.minecraft.chunks.PaletteType;
 import com.viaversion.viaversion.api.type.Type;
 import io.netty.buffer.ByteBuf;

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

@@ -24,7 +24,6 @@ package com.viaversion.viaversion.api.type.types.item;
 
 import com.google.common.base.Preconditions;
 import com.viaversion.viaversion.api.data.FullMappings;
-import com.viaversion.viaversion.api.data.item.ItemHasher;
 import com.viaversion.viaversion.api.minecraft.codec.Ops;
 import com.viaversion.viaversion.api.minecraft.data.StructuredData;
 import com.viaversion.viaversion.api.minecraft.data.StructuredDataKey;

api/src/main/java/com/viaversion/viaversion/api/type/types/math/MovementVectorType.java

@@ -0,0 +1,116 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.type.types.math;
+
+import com.viaversion.viaversion.api.minecraft.Vector3d;
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.api.type.types.UnsignedIntType;
+import com.viaversion.viaversion.util.MathUtil;
+import io.netty.buffer.ByteBuf;
+
+public class MovementVectorType extends Type<Vector3d> {
+    // Using 15 bits, steal short constants for it
+    private static final double MAX_QUANTIZED_VALUE = Short.MAX_VALUE - 1;
+    private static final int SCALE_BITS = 2; // first 2 bits for the scale
+    private static final int SCALE_BITS_MASK = 3;
+    private static final int CONTINUATION_FLAG = 1 << 2; // 3rd bit to indicate more scale data
+    private static final double ABS_MAX_VALUE = (1L << Integer.SIZE + SCALE_BITS) - 1; // Unsigned int + the first two scale bits
+    private static final double ABS_MIN_VALUE = 1 / MAX_QUANTIZED_VALUE;
+
+    public MovementVectorType() {
+        super(Vector3d.class);
+    }
+
+    @Override
+    public Vector3d read(final ByteBuf buffer) {
+        // Pack values back into a single long
+        final int first = Types.UNSIGNED_BYTE.read(buffer);
+        if (first == 0) {
+            return Vector3d.ZERO;
+        }
+
+        final int second = Types.UNSIGNED_BYTE.read(buffer);
+        final long remaining = Types.UNSIGNED_INT.read(buffer);
+        final long packed = remaining << 16 | second << 8 | first;
+
+        long scale = first & SCALE_BITS_MASK;
+        if ((first & CONTINUATION_FLAG) != 0) {
+            // Read the remaining bits and add them to the first two
+            scale |= (Types.VAR_INT.readPrimitive(buffer) & UnsignedIntType.MAX_UNSIGNED_INT) << SCALE_BITS;
+        }
+
+        // 15 bits for each part after removing the scale bits
+        return new Vector3d(
+            unpack(packed >> (0 + SCALE_BITS_MASK)) * scale,
+            unpack(packed >> (15 + SCALE_BITS_MASK)) * scale,
+            unpack(packed >> (30 + SCALE_BITS_MASK)) * scale
+        );
+    }
+
+    @Override
+    public void write(final ByteBuf buffer, final Vector3d vec) {
+        final double x = sanitize(vec.x());
+        final double y = sanitize(vec.y());
+        final double z = sanitize(vec.z());
+
+        final double maxPart = Math.max(Math.abs(x), Math.max(Math.abs(y), Math.abs(z)));
+        if (maxPart < ABS_MIN_VALUE) {
+            buffer.writeByte(0);
+            return;
+        }
+
+        final long scale = MathUtil.ceilLong(maxPart);
+        final boolean scaleTooLargeForBits = (scale & SCALE_BITS_MASK) != scale;
+        final long scaleBits = scaleTooLargeForBits ? (scale & SCALE_BITS_MASK) | CONTINUATION_FLAG : scale;
+        final long packed = scaleBits
+            | (pack(x / scale) << (0 + SCALE_BITS_MASK))
+            | (pack(y / scale) << (15 + SCALE_BITS_MASK))
+            | (pack(z / scale) << (30 + SCALE_BITS_MASK));
+
+        buffer.writeByte((byte) packed);
+        buffer.writeByte((byte) (packed >> 8));
+        buffer.writeInt((int) (packed >> 16));
+
+        if (scaleTooLargeForBits) {
+            // First two bits have already been written
+            Types.VAR_INT.writePrimitive(buffer, (int) (scale >> SCALE_BITS));
+        }
+    }
+
+    private double sanitize(final double value) {
+        return Double.isNaN(value) ? 0 : MathUtil.clamp(value, -ABS_MAX_VALUE, ABS_MAX_VALUE);
+    }
+
+    private long pack(final double value) {
+        // Shift to [0, 1] and quantize to 15 bits
+        final double shifted = (value * 0.5) + 0.5;
+        return Math.round(shifted * MAX_QUANTIZED_VALUE);
+    }
+
+    private double unpack(final long value) {
+        // Normalize to [-1, 1]
+        final double clamped = Math.min(value & Short.MAX_VALUE, MAX_QUANTIZED_VALUE);
+        return (clamped * 2) / MAX_QUANTIZED_VALUE - 1;
+    }
+}

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

@@ -22,16 +22,27 @@
  */
 package com.viaversion.viaversion.api.type.types.misc;
 
+import com.google.common.base.Preconditions;
+import com.viaversion.viaversion.api.data.MappingDataBase;
 import com.viaversion.viaversion.api.minecraft.HolderSet;
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
 import com.viaversion.viaversion.api.type.OptionalType;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.util.Key;
 import io.netty.buffer.ByteBuf;
 
 public class HolderSetType extends Type<HolderSet> {
 
+    private final MappingDataBase.MappingType mappingType;
+
     public HolderSetType() {
+        this(null);
+    }
+
+    public HolderSetType(final MappingDataBase.MappingType mappingType) {
         super(HolderSet.class);
+        this.mappingType = mappingType;
     }
 
     @Override
@@ -63,6 +74,28 @@ public class HolderSetType extends Type<HolderSet> {
         }
     }
 
+    @Override
+    public void write(final Ops ops, final HolderSet value) {
+        if (value.hasTagKey()) {
+            ops.write(Types.TAG_KEY, Key.of(value.tagKey()));
+        } else {
+            Preconditions.checkArgument(mappingType != null, "Cannot write HolderSet with direct ids without a mapping type");
+            if (value.ids().length == 1) {
+                // Single entries are inlined
+                final Key key = ops.context().registryAccess().key(mappingType, value.ids()[0]);
+                ops.write(Types.RESOURCE_LOCATION, key);
+                return;
+            }
+
+            ops.writeList(list -> {
+                for (final int id : value.ids()) {
+                    final Key key = ops.context().registryAccess().key(mappingType, id);
+                    list.write(Types.RESOURCE_LOCATION, key);
+                }
+            });
+        }
+    }
+
     public static final class OptionalHolderSetType extends OptionalType<HolderSet> {
 
         public OptionalHolderSetType() {

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

@@ -22,16 +22,27 @@
  */
 package com.viaversion.viaversion.api.type.types.misc;
 
+import com.google.common.base.Preconditions;
+import com.viaversion.viaversion.api.data.MappingData;
 import com.viaversion.viaversion.api.minecraft.Holder;
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.util.Key;
 import io.netty.buffer.ByteBuf;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 public abstract class HolderType<T> extends Type<Holder<T>> {
 
+    private final MappingData.MappingType mappingType;
+
     protected HolderType() {
+        this(null);
+    }
+
+    protected HolderType(final MappingData.MappingType mappingType) {
         super(Holder.class);
+        this.mappingType = mappingType;
     }
 
     @Override
@@ -57,6 +68,24 @@ public abstract class HolderType<T> extends Type<Holder<T>> {
 
     public abstract void writeDirect(final ByteBuf buffer, final T object);
 
+    @Override
+    public void write(final Ops ops, final Holder<T> value) {
+        if (value.hasId()) {
+            ops.write(Types.RESOURCE_LOCATION, identifier(ops, value.id()));
+        } else {
+            writeDirect(ops, value.value());
+        }
+    }
+
+    protected Key identifier(final Ops ops, final int id) {
+        Preconditions.checkArgument(mappingType != null, "Mapping type is not defined for this HolderType");
+        return ops.context().registryAccess().key(mappingType, id);
+    }
+
+    public void writeDirect(final Ops ops, final T object) {
+        throw new UnsupportedOperationException("Write operation not supported for type: " + getTypeName());
+    }
+
     public abstract static class OptionalHolderType<T> extends HolderType<T> {
         private final HolderType<T> type;
 

api/src/main/java/com/viaversion/viaversion/api/type/types/misc/LengthPrefixedTagType.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.type.types.misc;
+
+import com.google.common.base.Preconditions;
+import com.viaversion.nbt.tag.Tag;
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.Types;
+import io.netty.buffer.ByteBuf;
+
+public final class LengthPrefixedTagType extends Type<Tag> {
+
+    private final int maxLength;
+
+    public LengthPrefixedTagType(int maxLength) {
+        super(Tag.class);
+        this.maxLength = maxLength;
+    }
+
+    @Override
+    public Tag read(final ByteBuf buffer) {
+        final int length = Types.VAR_INT.readPrimitive(buffer);
+
+        Preconditions.checkArgument(length <= maxLength,
+            "Cannot receive tag longer than %s bytes (got %s bytes)", maxLength, length);
+
+        return Types.TAG.read(buffer.readSlice(length));
+    }
+
+    @Override
+    public void write(final ByteBuf buffer, final Tag tag) {
+        final ByteBuf tempBuf = buffer.alloc().buffer();
+        try {
+            Types.TAG.write(tempBuf, tag);
+
+            Preconditions.checkArgument(tempBuf.readableBytes() <= maxLength,
+                "Cannot send tag longer than %s bytes (got %s bytes)", maxLength, tempBuf.readableBytes());
+
+            Types.VAR_INT.writePrimitive(buffer, tempBuf.readableBytes());
+            buffer.writeBytes(tempBuf);
+        } finally {
+            tempBuf.release();
+        }
+    }
+}

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

@@ -160,6 +160,13 @@ public class ParticleType extends DynamicType<Particle> {
             particle.add(Types.INT, Types.INT.readPrimitive(buf)); // Color
             particle.add(Types.VAR_INT, Types.VAR_INT.readPrimitive(buf)); // Duration
         };
+        public static final DataReader<Particle> POWER = (buf, particle) -> {
+            particle.add(Types.FLOAT, Types.FLOAT.readPrimitive(buf));
+        };
+        public static final DataReader<Particle> SPELL = (buf, particle) -> {
+            particle.add(Types.INT, Types.INT.readPrimitive(buf)); // Color
+            particle.add(Types.FLOAT, Types.FLOAT.readPrimitive(buf)); // Power
+        };
 
         public static DataReader<Particle> item(Type<Item> item) {
             return (buf, particle) -> particle.add(item, item.read(buf));

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

@@ -0,0 +1,90 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.type.types.misc;
+
+import com.viaversion.viaversion.api.minecraft.GameProfile;
+import com.viaversion.viaversion.api.minecraft.ResolvableProfile;
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.util.Key;
+import io.netty.buffer.ByteBuf;
+import java.util.UUID;
+
+public final class ResolvableProfileType extends Type<ResolvableProfile> {
+
+    public ResolvableProfileType() {
+        super(ResolvableProfile.class);
+    }
+
+    @Override
+    public ResolvableProfile read(final ByteBuf buffer) {
+        final GameProfile profile;
+        if (buffer.readBoolean()) {
+            final UUID id = Types.UUID.read(buffer);
+            final String name = Types.STRING.read(buffer);
+            final GameProfile.Property[] properties = Types.PROFILE_PROPERTY_ARRAY.read(buffer);
+            profile = new GameProfile(name, id, properties, false);
+        } else {
+            profile = Types.GAME_PROFILE.read(buffer);
+        }
+
+        final String texture = Types.OPTIONAL_STRING.read(buffer);
+        final String capeTexture = Types.OPTIONAL_STRING.read(buffer);
+        final String elytraTexture = Types.OPTIONAL_STRING.read(buffer);
+        final Boolean encodedModelType = Types.OPTIONAL_BOOLEAN.read(buffer); // ...
+        final Integer modelType = encodedModelType != null ? (encodedModelType ? 0 : 1) : null;
+        return new ResolvableProfile(profile, texture, capeTexture, elytraTexture, modelType);
+    }
+
+    @Override
+    public void write(final ByteBuf buffer, final ResolvableProfile value) {
+        final GameProfile profile = value.profile();
+        if (!profile.dynamic()) {
+            buffer.writeBoolean(true);
+            Types.UUID.write(buffer, profile.id());
+            Types.STRING.write(buffer, profile.name());
+            Types.PROFILE_PROPERTY_ARRAY.write(buffer, profile.properties());
+        } else {
+            buffer.writeBoolean(false);
+            Types.GAME_PROFILE.write(buffer, profile);
+        }
+
+        Types.OPTIONAL_STRING.write(buffer, value.bodyTexture());
+        Types.OPTIONAL_STRING.write(buffer, value.capeTexture());
+        Types.OPTIONAL_STRING.write(buffer, value.elytraTexture());
+        Types.OPTIONAL_BOOLEAN.write(buffer, value.modelType() != null ? value.modelType() == 0 : null);
+    }
+
+    @Override
+    public void write(final Ops ops, final ResolvableProfile value) {
+        final String modelType = value.modelType() != null ? (value.modelType() == 0 ? "slim" : "wide") : null;
+        ops.writeMap(map -> map
+            .writeInlinedMap(Types.GAME_PROFILE, value.profile())
+            .writeOptional("texture", Types.RESOURCE_LOCATION, value.bodyTexture() != null ? Key.of(value.bodyTexture()) : null)
+            .writeOptional("cape", Types.RESOURCE_LOCATION, value.capeTexture() != null ? Key.of(value.capeTexture()) : null)
+            .writeOptional("elytra", Types.RESOURCE_LOCATION, value.elytraTexture() != null ? Key.of(value.elytraTexture()) : null)
+            .writeOptional("model", Types.OPTIONAL_STRING, modelType)
+        );
+    }
+};

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

@@ -22,12 +22,19 @@
  */
 package com.viaversion.viaversion.api.type.types.misc;
 
+import com.viaversion.viaversion.api.data.MappingData;
 import com.viaversion.viaversion.api.minecraft.SoundEvent;
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
 import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.util.Key;
 import io.netty.buffer.ByteBuf;
 
 public final class SoundEventType extends HolderType<SoundEvent> {
 
+    public SoundEventType() {
+        super(MappingData.MappingType.SOUND);
+    }
+
     @Override
     public SoundEvent readDirect(final ByteBuf buffer) {
         final String resourceLocation = Types.STRING.read(buffer);
@@ -41,6 +48,13 @@ public final class SoundEventType extends HolderType<SoundEvent> {
         Types.OPTIONAL_FLOAT.write(buffer, value.fixedRange());
     }
 
+    @Override
+    public void writeDirect(final Ops ops, final SoundEvent object) {
+        ops.writeMap(map -> map
+            .write("sound_id", Types.RESOURCE_LOCATION, Key.of(object.identifier()))
+            .writeOptional("range", Types.FLOAT, object.fixedRange()));
+    }
+
     public static final class OptionalSoundEventType extends OptionalHolderType<SoundEvent> {
 
         public OptionalSoundEventType() {

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

@@ -105,13 +105,13 @@ public class TagType extends Type<Tag> {
         } else if (value instanceof CompoundTag compoundTag) {
             ops.writeMap(map -> {
                 for (final Map.Entry<String, Tag> entry : compoundTag.entrySet()) {
-                    map.write(entry.getKey(), Types.TAG, entry.getValue());
+                    map.write(entry.getKey(), this, entry.getValue());
                 }
             });
         } else if (value instanceof ListTag<?> listTag) {
             ops.writeList(list -> {
                 for (final Tag tag : listTag) {
-                    list.write(Types.TAG, tag);
+                    list.write(this, tag);
                 }
             });
         } else if (value instanceof IntArrayTag intArrayTag) {

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

@@ -0,0 +1,61 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2025 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.type.types.misc;
+
+import com.viaversion.nbt.tag.ByteTag;
+import com.viaversion.nbt.tag.CompoundTag;
+import com.viaversion.nbt.tag.Tag;
+import com.viaversion.viaversion.api.minecraft.codec.Ops;
+import com.viaversion.viaversion.api.type.Types;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * Only strictly needed for hashing purposes for now.
+ */
+public class TextComponentTagType extends TagType {
+
+    private static final Set<String> BOOLEAN_KEYS = Set.of("bold", "italic", "underlined", "strikethrough", "obfuscated", "interpret");
+
+    @Override
+    public void write(final Ops ops, final Tag value) {
+        if (value instanceof final CompoundTag compoundTag) {
+            ops.writeMap(map -> {
+                for (final Map.Entry<String, Tag> entry : compoundTag.entrySet()) {
+                    write(map, entry.getKey(), entry.getValue());
+                }
+            });
+        } else {
+            super.write(ops, value);
+        }
+    }
+
+    private void write(final Ops.MapSerializer map, final String key, final Tag value) {
+        // Better than fully parsing and re-serializing the component
+        if (value instanceof final ByteTag byteTag && BOOLEAN_KEYS.contains(key)) {
+            map.write(key, Types.BOOLEAN, byteTag.asBoolean());
+        } else {
+            map.write(key, this, value);
+        }
+    }
+}

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

@@ -29,6 +29,7 @@ import com.viaversion.viaversion.api.minecraft.entitydata.types.EntityDataTypes1
 import com.viaversion.viaversion.api.minecraft.entitydata.types.EntityDataTypes1_21;
 import com.viaversion.viaversion.api.minecraft.entitydata.types.EntityDataTypes1_21_2;
 import com.viaversion.viaversion.api.minecraft.entitydata.types.EntityDataTypes1_21_5;
+import com.viaversion.viaversion.api.minecraft.entitydata.types.EntityDataTypes1_21_9;
 
 /**
  * Holds versioned accessors for highly volatile types, specifically around items and data components.
@@ -44,4 +45,5 @@ public final class VersionedTypes {
     public static final Types1_20_5<StructuredDataKeys1_21_2, EntityDataTypes1_21_2> V1_21_4 = new Types1_20_5<>(StructuredDataKeys1_21_2::new, EntityDataTypes1_21_2::new);
     public static final Types1_20_5<StructuredDataKeys1_21_5, EntityDataTypes1_21_5> V1_21_5 = new Types1_20_5<>(StructuredDataKeys1_21_5::new, EntityDataTypes1_21_5::new);
     public static final Types1_20_5<StructuredDataKeys1_21_5, EntityDataTypes1_21_5> V1_21_6 = new Types1_20_5<>(StructuredDataKeys1_21_5::new, EntityDataTypes1_21_5::new);
+    public static final Types1_20_5<StructuredDataKeys1_21_5, EntityDataTypes1_21_9> V1_21_9 = new Types1_20_5<>(StructuredDataKeys1_21_5::new, EntityDataTypes1_21_9::new);
 }

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

@@ -22,6 +22,7 @@
  */
 package com.viaversion.viaversion.util;
 
+import java.lang.reflect.Array;
 import java.util.Arrays;
 
 /**
@@ -76,4 +77,21 @@ public final class ArrayUtil {
         }
         return boxedArray;
     }
+
+    public static String toString(final Object o) {
+        if (o == null || !o.getClass().isArray()) {
+            return String.valueOf(o);
+        }
+
+        final int length = Array.getLength(o);
+        final StringBuilder builder = new StringBuilder("[");
+        for (int i = 0; i < length; i++) {
+            if (i > 0) {
+                builder.append(", ");
+            }
+            builder.append(Array.get(o, i));
+        }
+        builder.append("]");
+        return builder.toString();
+    }
 }

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

@@ -25,8 +25,8 @@ package com.viaversion.viaversion.util;
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.google.gson.JsonElement;
+import com.viaversion.viaversion.libs.mcstructs.text.utils.JsonUtils;
 import java.util.Comparator;
-import net.lenni0451.mcstructs.text.utils.JsonUtils;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 public final class GsonUtil {

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

@@ -124,7 +124,7 @@ public final class Key {
     }
 
     public static boolean equals(final String firstIdentifier, final String secondIdentifier) {
-        return of(firstIdentifier).equals(of(secondIdentifier));
+        return firstIdentifier != null && secondIdentifier != null && of(firstIdentifier).equals(of(secondIdentifier));
     }
 
     public static String namespaced(final String identifier) {

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

@@ -24,6 +24,22 @@ package com.viaversion.viaversion.util;
 
 public final class MathUtil {
 
+    /**
+     * Miniscule value below which positive floats are considered zero
+     */
+    public static final float EPSILON = 1.0E-5F;
+
+    /**
+     * Returns the ceiled integer value of the given float.
+     *
+     * @param value float value to ceil
+     * @return ceiled integer value
+     */
+    public static int ceil(final float value) {
+        final int intValue = (int) value;
+        return value > intValue ? intValue + 1 : intValue;
+    }
+
     /**
      * Returns the ceiled log to the base of 2 for the given number.
      *
@@ -34,6 +50,11 @@ public final class MathUtil {
         return i > 0 ? 32 - Integer.numberOfLeadingZeros(i - 1) : 0;
     }
 
+    public static long ceilLong(final double d) {
+        final long l = (long) d;
+        return d > l ? l + 1 : l;
+    }
+
     /**
      * Returns the clamped number within the given range.
      *
@@ -48,4 +69,11 @@ public final class MathUtil {
         }
         return i > max ? max : i;
     }
+
+    public static double clamp(final double d, final double min, final double max) {
+        if (d < min) {
+            return min;
+        }
+        return d > max ? max : d;
+    }
 }

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

@@ -67,7 +67,12 @@ public interface Rewritable {
 
     static Int2IntFunction soundRewriteFunction(final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
         return protocol.getMappingData().getSoundMappings() == null ? Int2IntFunction.identity()
-            : (clientbound ? protocol.getMappingData()::getNewSoundId : protocol.getMappingData()::getOldSoundId);
+            : (clientbound ? protocol.getMappingData().getSoundMappings()::getNewId : protocol.getMappingData()::getOldSoundId);
+    }
+
+    static Int2IntFunction entityRewriteFunction(final Protocol<?, ?, ?, ?> protocol, final boolean clientbound) {
+        return protocol.getMappingData().getEntityMappings() == null ? Int2IntFunction.identity()
+            : (clientbound ? protocol.getMappingData().getEntityMappings()::getNewId : protocol.getMappingData().getEntityMappings().inverse()::getNewId);
     }
 
     static @Nullable String mappedIdentifier(final FullMappings mappings, final String identifier) {