diff --git a/api/src/main/java/com/viaversion/viaversion/api/minecraft/data/StructuredDataKey.java b/api/src/main/java/com/viaversion/viaversion/api/minecraft/data/StructuredDataKey.java
index 0944c5d55..7f40096ce 100644
--- a/api/src/main/java/com/viaversion/viaversion/api/minecraft/data/StructuredDataKey.java
+++ b/api/src/main/java/com/viaversion/viaversion/api/minecraft/data/StructuredDataKey.java
@@ -52,6 +52,7 @@ import com.viaversion.viaversion.api.minecraft.item.data.WrittenBook;
 import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.api.type.Types;
 import com.viaversion.viaversion.api.type.types.version.Types1_20_5;
+import com.viaversion.viaversion.api.type.types.version.Types1_21;
 import com.viaversion.viaversion.util.Unit;
 
 public record StructuredDataKey<T>(String identifier, Type<T> type) {
@@ -87,8 +88,10 @@ public record StructuredDataKey<T>(String identifier, Type<T> type) {
     public static final StructuredDataKey<Integer> MAP_ID = new StructuredDataKey<>("map_id", Types.VAR_INT);
     public static final StructuredDataKey<CompoundTag> MAP_DECORATIONS = new StructuredDataKey<>("map_decorations", Types.COMPOUND_TAG);
     public static final StructuredDataKey<Integer> MAP_POST_PROCESSING = new StructuredDataKey<>("map_post_processing", Types.VAR_INT);
-    public static final StructuredDataKey<Item[]> CHARGED_PROJECTILES = new StructuredDataKey<>("charged_projectiles", Types1_20_5.ITEM_ARRAY);
-    public static final StructuredDataKey<Item[]> BUNDLE_CONTENTS = new StructuredDataKey<>("bundle_contents", Types1_20_5.ITEM_ARRAY);
+    public static final StructuredDataKey<Item[]> CHARGED_PROJECTILES1_20_5 = new StructuredDataKey<>("charged_projectiles", Types1_20_5.ITEM_ARRAY);
+    public static final StructuredDataKey<Item[]> CHARGED_PROJECTILES1_21 = new StructuredDataKey<>("charged_projectiles", Types1_21.ITEM_ARRAY);
+    public static final StructuredDataKey<Item[]> BUNDLE_CONTENTS1_20_5 = new StructuredDataKey<>("bundle_contents", Types1_20_5.ITEM_ARRAY);
+    public static final StructuredDataKey<Item[]> BUNDLE_CONTENTS1_21 = new StructuredDataKey<>("bundle_contents", Types1_21.ITEM_ARRAY);
     public static final StructuredDataKey<PotionContents> POTION_CONTENTS = new StructuredDataKey<>("potion_contents", PotionContents.TYPE);
     public static final StructuredDataKey<SuspiciousStewEffect[]> SUSPICIOUS_STEW_EFFECTS = new StructuredDataKey<>("suspicious_stew_effects", SuspiciousStewEffect.ARRAY_TYPE);
     public static final StructuredDataKey<FilterableString[]> WRITABLE_BOOK_CONTENT = new StructuredDataKey<>("writable_book_content", FilterableString.ARRAY_TYPE);
@@ -110,7 +113,8 @@ public record StructuredDataKey<T>(String identifier, Type<T> type) {
     public static final StructuredDataKey<BannerPatternLayer[]> BANNER_PATTERNS = new StructuredDataKey<>("banner_patterns", BannerPatternLayer.ARRAY_TYPE);
     public static final StructuredDataKey<Integer> BASE_COLOR = new StructuredDataKey<>("base_color", Types.VAR_INT);
     public static final StructuredDataKey<PotDecorations> POT_DECORATIONS = new StructuredDataKey<>("pot_decorations", PotDecorations.TYPE);
-    public static final StructuredDataKey<Item[]> CONTAINER = new StructuredDataKey<>("container", Types1_20_5.ITEM_ARRAY);
+    public static final StructuredDataKey<Item[]> CONTAINER1_20_5 = new StructuredDataKey<>("container", Types1_20_5.ITEM_ARRAY);
+    public static final StructuredDataKey<Item[]> CONTAINER1_21 = new StructuredDataKey<>("container", Types1_21.ITEM_ARRAY);
     public static final StructuredDataKey<BlockStateProperties> BLOCK_STATE = new StructuredDataKey<>("block_state", BlockStateProperties.TYPE);
     public static final StructuredDataKey<Bee[]> BEES = new StructuredDataKey<>("bees", Bee.ARRAY_TYPE);
     public static final StructuredDataKey<Tag> LOCK = new StructuredDataKey<>("lock", Types.TAG);
diff --git a/api/src/main/java/com/viaversion/viaversion/api/type/types/item/StructuredDataType.java b/api/src/main/java/com/viaversion/viaversion/api/type/types/item/StructuredDataType.java
index 8b51ff967..28e35ba8c 100644
--- a/api/src/main/java/com/viaversion/viaversion/api/type/types/item/StructuredDataType.java
+++ b/api/src/main/java/com/viaversion/viaversion/api/type/types/item/StructuredDataType.java
@@ -83,6 +83,7 @@ public class StructuredDataType extends Type<StructuredData<?>> {
         public DataFiller add(final StructuredDataKey<?> key) {
             final int id = mappings.mappedId(key.identifier());
             Preconditions.checkArgument(id != -1, "No mapped id found for %s", key.identifier());
+            Preconditions.checkArgument(types[id] == null, "Data component serializer already exists for id %s", id);
             types[id] = key;
             return this;
         }
diff --git a/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/Protocol1_20_3To1_20_5.java b/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/Protocol1_20_3To1_20_5.java
index 5c9ba7a74..8a7c3a56d 100644
--- a/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/Protocol1_20_3To1_20_5.java
+++ b/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/Protocol1_20_3To1_20_5.java
@@ -268,14 +268,14 @@ public final class Protocol1_20_3To1_20_5 extends AbstractProtocol<ClientboundPa
             .add(StructuredDataKey.CREATIVE_SLOT_LOCK).add(StructuredDataKey.ENCHANTMENT_GLINT_OVERRIDE).add(StructuredDataKey.INTANGIBLE_PROJECTILE)
             .add(StructuredDataKey.STORED_ENCHANTMENTS).add(StructuredDataKey.DYED_COLOR).add(StructuredDataKey.MAP_COLOR)
             .add(StructuredDataKey.MAP_ID).add(StructuredDataKey.MAP_DECORATIONS).add(StructuredDataKey.MAP_POST_PROCESSING)
-            .add(StructuredDataKey.CHARGED_PROJECTILES).add(StructuredDataKey.BUNDLE_CONTENTS).add(StructuredDataKey.POTION_CONTENTS)
+            .add(StructuredDataKey.CHARGED_PROJECTILES1_20_5).add(StructuredDataKey.BUNDLE_CONTENTS1_20_5).add(StructuredDataKey.POTION_CONTENTS)
             .add(StructuredDataKey.SUSPICIOUS_STEW_EFFECTS).add(StructuredDataKey.WRITABLE_BOOK_CONTENT).add(StructuredDataKey.WRITTEN_BOOK_CONTENT)
             .add(StructuredDataKey.TRIM).add(StructuredDataKey.DEBUG_STICK_STATE).add(StructuredDataKey.ENTITY_DATA)
             .add(StructuredDataKey.BUCKET_ENTITY_DATA).add(StructuredDataKey.BLOCK_ENTITY_DATA).add(StructuredDataKey.INSTRUMENT)
             .add(StructuredDataKey.RECIPES).add(StructuredDataKey.LODESTONE_TRACKER).add(StructuredDataKey.FIREWORK_EXPLOSION)
             .add(StructuredDataKey.FIREWORKS).add(StructuredDataKey.PROFILE).add(StructuredDataKey.NOTE_BLOCK_SOUND)
             .add(StructuredDataKey.BANNER_PATTERNS).add(StructuredDataKey.BASE_COLOR).add(StructuredDataKey.POT_DECORATIONS)
-            .add(StructuredDataKey.CONTAINER).add(StructuredDataKey.BLOCK_STATE).add(StructuredDataKey.BEES)
+            .add(StructuredDataKey.CONTAINER1_20_5).add(StructuredDataKey.BLOCK_STATE).add(StructuredDataKey.BEES)
             .add(StructuredDataKey.LOCK).add(StructuredDataKey.CONTAINER_LOOT).add(StructuredDataKey.TOOL)
             .add(StructuredDataKey.ITEM_NAME).add(StructuredDataKey.OMINOUS_BOTTLE_AMPLIFIER);
 
diff --git a/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/rewriter/BlockItemPacketRewriter1_20_5.java b/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/rewriter/BlockItemPacketRewriter1_20_5.java
index edf815108..56df2e4c7 100644
--- a/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/rewriter/BlockItemPacketRewriter1_20_5.java
+++ b/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/rewriter/BlockItemPacketRewriter1_20_5.java
@@ -536,9 +536,9 @@ public final class BlockItemPacketRewriter1_20_5 extends ItemRewriter<Clientboun
 
         updateMobTags(data, tag);
 
-        updateItemList(connection, data, tag, "ChargedProjectiles", StructuredDataKey.CHARGED_PROJECTILES, false);
+        updateItemList(connection, data, tag, "ChargedProjectiles", StructuredDataKey.CHARGED_PROJECTILES1_20_5, false);
         if (old.identifier() == 927) {
-            updateItemList(connection, data, tag, "Items", StructuredDataKey.BUNDLE_CONTENTS, false);
+            updateItemList(connection, data, tag, "Items", StructuredDataKey.BUNDLE_CONTENTS1_20_5, false);
         }
 
         updateEnchantments(data, tag, "Enchantments", StructuredDataKey.ENCHANTMENTS, (hideFlagsValue & StructuredDataConverter.HIDE_ENCHANTMENTS) == 0);
@@ -1443,7 +1443,7 @@ public final class BlockItemPacketRewriter1_20_5 extends ItemRewriter<Clientboun
                 data.set(StructuredDataKey.BASE_COLOR, baseColorIntTag.asInt());
             }
 
-            updateItemList(connection, data, tag, "Items", StructuredDataKey.CONTAINER, true);
+            updateItemList(connection, data, tag, "Items", StructuredDataKey.CONTAINER1_20_5, true);
         }
 
         final Tag skullOwnerTag = tag.remove("SkullOwner");
diff --git a/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/rewriter/ComponentRewriter1_20_5.java b/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/rewriter/ComponentRewriter1_20_5.java
index 2f8d7e821..c079df632 100644
--- a/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/rewriter/ComponentRewriter1_20_5.java
+++ b/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/rewriter/ComponentRewriter1_20_5.java
@@ -143,8 +143,8 @@ public class ComponentRewriter1_20_5<C extends ClientboundPacketType> extends Co
         register(StructuredDataKey.MAP_ID, this::convertMapId);
         register(StructuredDataKey.MAP_DECORATIONS, this::convertMapDecorations);
         register(StructuredDataKey.MAP_POST_PROCESSING, null);
-        register(StructuredDataKey.CHARGED_PROJECTILES, this::convertChargedProjectiles);
-        register(StructuredDataKey.BUNDLE_CONTENTS, this::convertBundleContents);
+        register(StructuredDataKey.CHARGED_PROJECTILES1_20_5, this::convertChargedProjectiles);
+        register(StructuredDataKey.BUNDLE_CONTENTS1_20_5, this::convertBundleContents);
         register(StructuredDataKey.POTION_CONTENTS, this::convertPotionContents);
         register(StructuredDataKey.SUSPICIOUS_STEW_EFFECTS, this::convertSuspiciousStewEffects);
         register(StructuredDataKey.WRITABLE_BOOK_CONTENT, this::convertWritableBookContent);
@@ -165,7 +165,7 @@ public class ComponentRewriter1_20_5<C extends ClientboundPacketType> extends Co
         register(StructuredDataKey.BANNER_PATTERNS, this::convertBannerPatterns);
         register(StructuredDataKey.BASE_COLOR, this::convertBaseColor);
         register(StructuredDataKey.POT_DECORATIONS, this::convertPotDecorations);
-        register(StructuredDataKey.CONTAINER, this::convertContainer);
+        register(StructuredDataKey.CONTAINER1_20_5, this::convertContainer);
         register(StructuredDataKey.BLOCK_STATE, this::convertBlockState);
         register(StructuredDataKey.BEES, this::convertBees);
         register(StructuredDataKey.LOCK, this::convertLock);
diff --git a/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/rewriter/StructuredDataConverter.java b/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/rewriter/StructuredDataConverter.java
index 00bb7d4bd..5fe8adb56 100644
--- a/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/rewriter/StructuredDataConverter.java
+++ b/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/rewriter/StructuredDataConverter.java
@@ -218,8 +218,8 @@ public final class StructuredDataConverter {
             }
         });
         register(StructuredDataKey.BASE_COLOR, (data, tag) -> getBlockEntityTag(tag).putInt("Base", data));
-        register(StructuredDataKey.CHARGED_PROJECTILES, (connection, data, tag) -> convertItemList(connection, data, tag, "ChargedProjectiles"));
-        register(StructuredDataKey.BUNDLE_CONTENTS, (connection, data, tag) -> convertItemList(connection, data, tag, "Items"));
+        register(StructuredDataKey.CHARGED_PROJECTILES1_20_5, (connection, data, tag) -> convertItemList(connection, data, tag, "ChargedProjectiles"));
+        register(StructuredDataKey.BUNDLE_CONTENTS1_20_5, (connection, data, tag) -> convertItemList(connection, data, tag, "Items"));
         register(StructuredDataKey.LODESTONE_TRACKER, (data, tag) -> {
             tag.putBoolean("LodestoneTracked", data.tracked());
             if (data.position() != null) {
@@ -494,7 +494,7 @@ public final class StructuredDataConverter {
             }
             getBlockEntityTag(tag, "banner").put("Patterns", patternsTag);
         });
-        register(StructuredDataKey.CONTAINER, (connection, data, tag) -> convertItemList(connection, data, getBlockEntityTag(tag), "Items"));
+        register(StructuredDataKey.CONTAINER1_20_5, (connection, data, tag) -> convertItemList(connection, data, getBlockEntityTag(tag), "Items"));
         register(StructuredDataKey.CAN_PLACE_ON, (data, tag) -> convertBlockPredicates(tag, data, "CanPlaceOn", HIDE_CAN_PLACE_ON));
         register(StructuredDataKey.CAN_BREAK, (data, tag) -> convertBlockPredicates(tag, data, "CanDestroy", HIDE_CAN_DESTROY));
         register(StructuredDataKey.MAP_POST_PROCESSING, (data, tag) -> {
diff --git a/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_5to1_21/Protocol1_20_5To1_21.java b/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_5to1_21/Protocol1_20_5To1_21.java
index 85ef81a71..7bb46567d 100644
--- a/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_5to1_21/Protocol1_20_5To1_21.java
+++ b/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_5to1_21/Protocol1_20_5To1_21.java
@@ -199,14 +199,14 @@ public final class Protocol1_20_5To1_21 extends AbstractProtocol<ClientboundPack
             .add(StructuredDataKey.CREATIVE_SLOT_LOCK).add(StructuredDataKey.ENCHANTMENT_GLINT_OVERRIDE).add(StructuredDataKey.INTANGIBLE_PROJECTILE)
             .add(StructuredDataKey.STORED_ENCHANTMENTS).add(StructuredDataKey.DYED_COLOR).add(StructuredDataKey.MAP_COLOR)
             .add(StructuredDataKey.MAP_ID).add(StructuredDataKey.MAP_DECORATIONS).add(StructuredDataKey.MAP_POST_PROCESSING)
-            .add(StructuredDataKey.CHARGED_PROJECTILES).add(StructuredDataKey.BUNDLE_CONTENTS).add(StructuredDataKey.POTION_CONTENTS)
+            .add(StructuredDataKey.CHARGED_PROJECTILES1_21).add(StructuredDataKey.BUNDLE_CONTENTS1_21).add(StructuredDataKey.POTION_CONTENTS)
             .add(StructuredDataKey.SUSPICIOUS_STEW_EFFECTS).add(StructuredDataKey.WRITABLE_BOOK_CONTENT).add(StructuredDataKey.WRITTEN_BOOK_CONTENT)
             .add(StructuredDataKey.TRIM).add(StructuredDataKey.DEBUG_STICK_STATE).add(StructuredDataKey.ENTITY_DATA)
             .add(StructuredDataKey.BUCKET_ENTITY_DATA).add(StructuredDataKey.BLOCK_ENTITY_DATA).add(StructuredDataKey.INSTRUMENT)
             .add(StructuredDataKey.RECIPES).add(StructuredDataKey.LODESTONE_TRACKER).add(StructuredDataKey.FIREWORK_EXPLOSION)
             .add(StructuredDataKey.FIREWORKS).add(StructuredDataKey.PROFILE).add(StructuredDataKey.NOTE_BLOCK_SOUND)
             .add(StructuredDataKey.BANNER_PATTERNS).add(StructuredDataKey.BASE_COLOR).add(StructuredDataKey.POT_DECORATIONS)
-            .add(StructuredDataKey.CONTAINER).add(StructuredDataKey.BLOCK_STATE).add(StructuredDataKey.BEES)
+            .add(StructuredDataKey.CONTAINER1_21).add(StructuredDataKey.BLOCK_STATE).add(StructuredDataKey.BEES)
             .add(StructuredDataKey.LOCK).add(StructuredDataKey.CONTAINER_LOOT).add(StructuredDataKey.TOOL)
             .add(StructuredDataKey.ITEM_NAME).add(StructuredDataKey.OMINOUS_BOTTLE_AMPLIFIER)
             .add(StructuredDataKey.FOOD1_21).add(StructuredDataKey.JUKEBOX_PLAYABLE).add(StructuredDataKey.ATTRIBUTE_MODIFIERS1_21);
diff --git a/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_5to1_21/rewriter/BlockItemPacketRewriter1_21.java b/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_5to1_21/rewriter/BlockItemPacketRewriter1_21.java
index 53bed0e3b..0b19e33af 100644
--- a/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_5to1_21/rewriter/BlockItemPacketRewriter1_21.java
+++ b/common/src/main/java/com/viaversion/viaversion/protocols/v1_20_5to1_21/rewriter/BlockItemPacketRewriter1_21.java
@@ -120,6 +120,9 @@ public final class BlockItemPacketRewriter1_21 extends StructuredItemRewriter<Cl
     public static void updateItemData(final Item item) {
         final StructuredDataContainer dataContainer = item.dataContainer();
         dataContainer.replaceKey(StructuredDataKey.FOOD1_20_5, StructuredDataKey.FOOD1_21);
+        dataContainer.replaceKey(StructuredDataKey.CONTAINER1_20_5, StructuredDataKey.CONTAINER1_20_5);
+        dataContainer.replaceKey(StructuredDataKey.CHARGED_PROJECTILES1_20_5, StructuredDataKey.CHARGED_PROJECTILES1_21);
+        dataContainer.replaceKey(StructuredDataKey.BUNDLE_CONTENTS1_20_5, StructuredDataKey.BUNDLE_CONTENTS1_21);
         dataContainer.replace(StructuredDataKey.ATTRIBUTE_MODIFIERS1_20_5, StructuredDataKey.ATTRIBUTE_MODIFIERS1_21, attributeModifiers -> {
             final AttributeModifiers1_21.AttributeModifier[] modifiers = Arrays.stream(attributeModifiers.modifiers()).map(modifier -> {
                 final AttributeModifiers1_20_5.ModifierData modData = modifier.modifier();
@@ -144,6 +147,9 @@ public final class BlockItemPacketRewriter1_21 extends StructuredItemRewriter<Cl
     public static void downgradeItemData(final Item item) {
         final StructuredDataContainer dataContainer = item.dataContainer();
         dataContainer.replaceKey(StructuredDataKey.FOOD1_21, StructuredDataKey.FOOD1_20_5);
+        dataContainer.replaceKey(StructuredDataKey.CONTAINER1_21, StructuredDataKey.CONTAINER1_20_5);
+        dataContainer.replaceKey(StructuredDataKey.CHARGED_PROJECTILES1_21, StructuredDataKey.CHARGED_PROJECTILES1_20_5);
+        dataContainer.replaceKey(StructuredDataKey.BUNDLE_CONTENTS1_21, StructuredDataKey.BUNDLE_CONTENTS1_20_5);
         dataContainer.remove(StructuredDataKey.JUKEBOX_PLAYABLE);
         dataContainer.replace(StructuredDataKey.ATTRIBUTE_MODIFIERS1_21, StructuredDataKey.ATTRIBUTE_MODIFIERS1_20_5, attributeModifiers -> {
             final AttributeModifiers1_20_5.AttributeModifier[] modifiers = Arrays.stream(attributeModifiers.modifiers()).map(modifier -> {