PaperMC · Tmpod · Sep 19, 2025 · Sep 19, 2025
@@ -0,0 +1,67 @@
+package io.papermc.paper.event.entity;
+
+import org.bukkit.entity.Entity;
+import org.bukkit.event.HandlerList;
+import org.bukkit.event.entity.EntityEvent;
+import org.jetbrains.annotations.ApiStatus;
+import org.jspecify.annotations.NullMarked;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Called right before the scoreboard tags for an entity are changed.
+ */
+@NullMarked
+public class ScoreboardTagsChangeEvent extends EntityEvent {
+
+    private static final HandlerList HANDLER_LIST = new HandlerList();
+
+    private final List<String> tags;
+    private final Change change;
+
+    @ApiStatus.Internal
+    public ScoreboardTagsChangeEvent(final Entity entity, final List<String> tags, final Change change) {
+        super(entity);
+        this.tags = Collections.unmodifiableList(tags);
+        this.change = change;
+    }
+
+    /**
+     * Get the tags that are being added/removed/set.
+     *
+     * @return Tags being added/removed/set. Unmodifiable.
+     */
+    public List<String> getTags() {
+        return this.tags;
+    }
+
+    /**
+     * Gets the type of change happening to the entity's tags.
+     *
+     * @return Type of change happening.
+     */
+    public Change getChange() {
+        return this.change;
+    }
+
+    @Override
+    public HandlerList getHandlers() {
+        return HANDLER_LIST;
+    }
+
+    public static HandlerList getHandlerList() {
+        return HANDLER_LIST;
+    }
+
+    /**
+     * Represents the possible changes made to the entity's tags.
+     */
+    public enum Change {
+        /** The tags were added to the entity. */
+        ADD,
+        /** The tags were removed from the entity. */
+        REMOVE,
+        /** The tags replaced the entity's existing tags. */
+        SET,
+    }
+}
@@ -484,7 +484,7 @@ index c70a58f5f633fa8e255f74c42f5e87c96b7b013a..ec20a5a6d7c8f65abda528fec36bec7b
      public void tick() {
          super.tick();
 diff --git a/net/minecraft/world/entity/Entity.java b/net/minecraft/world/entity/Entity.java
-index b9f0745cdc42a093b69f46e353b99adf0c5aac56..a5d65e1b31e2e43cf039b8a19286a5324a739bbe 100644
+index a5c1c1f88f2e1930f46c18654a384b906ca66515..f9fea0ab2c7c5093ce7838073020f9985d6e58d0 100644
 --- a/net/minecraft/world/entity/Entity.java
 +++ b/net/minecraft/world/entity/Entity.java
 @@ -409,6 +409,15 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
@@ -517,7 +517,7 @@ index b9f0745cdc42a093b69f46e353b99adf0c5aac56..a5d65e1b31e2e43cf039b8a19286a532
          SynchedEntityData.Builder builder = new SynchedEntityData.Builder(this);
          builder.define(DATA_SHARED_FLAGS_ID, (byte)0);
          builder.define(DATA_AIR_SUPPLY_ID, this.getMaxAirSupply());
-@@ -984,6 +1000,10 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+@@ -986,6 +1002,10 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
              this.setPos(this.getX() + movement.x, this.getY() + movement.y, this.getZ() + movement.z);
          } else {
              if (type == MoverType.PISTON) {
@@ -528,7 +528,7 @@ index b9f0745cdc42a093b69f46e353b99adf0c5aac56..a5d65e1b31e2e43cf039b8a19286a532
                  movement = this.limitPistonMovement(movement);
                  if (movement.equals(Vec3.ZERO)) {
                      return;
-@@ -997,6 +1017,13 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+@@ -999,6 +1019,13 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
                  this.stuckSpeedMultiplier = Vec3.ZERO;
                  this.setDeltaMovement(Vec3.ZERO);
              }
@@ -543,7 +543,7 @@ index b9f0745cdc42a093b69f46e353b99adf0c5aac56..a5d65e1b31e2e43cf039b8a19286a532
              movement = this.maybeBackOffFromEdge(movement, type);
              Vec3 vec3 = this.collide(movement);
 diff --git a/net/minecraft/world/entity/LivingEntity.java b/net/minecraft/world/entity/LivingEntity.java
-index 8dd8a3d2a862998a920f226b2a6d9a877aac70a8..0c52e315557e1dae6a852694786e72241fff1e29 100644
+index bcdd4ad0482297c9ea376e3632722570e2dd4c23..0268e02d2ef2cb3d699644a804e23a6da4521f4c 100644
 --- a/net/minecraft/world/entity/LivingEntity.java
 +++ b/net/minecraft/world/entity/LivingEntity.java
 @@ -3215,6 +3215,14 @@ public abstract class LivingEntity extends Entity implements Attackable, Waypoin
@@ -562,7 +562,7 @@ index 8dd8a3d2a862998a920f226b2a6d9a877aac70a8..0c52e315557e1dae6a852694786e7224
      public void tick() {
          super.tick();
 diff --git a/net/minecraft/world/entity/Mob.java b/net/minecraft/world/entity/Mob.java
-index c737fd87e804129fac95be7d19b4aafab38d8b94..21c6d4746c6a905ec312dc1e35535cbd13868322 100644
+index 63f0b0a39e51b1cd30c2d131414d9512886a664f..e0b3cb2b2694768803ed347a1026b881fd624951 100644
 --- a/net/minecraft/world/entity/Mob.java
 +++ b/net/minecraft/world/entity/Mob.java
 @@ -207,6 +207,19 @@ public abstract class Mob extends LivingEntity implements EquipmentUser, Leashab
@@ -838,7 +838,7 @@ index 52acc72841f0c6980f5f3f8ef21d0b29dd472ce3..41a6ec508a10a49a37539d2f10171d15
 +
  }
 diff --git a/net/minecraft/world/level/Level.java b/net/minecraft/world/level/Level.java
-index 06069d3ac598f5f12feab038de4f1199794298f6..980eaba27ce2616c1573a4760cf4acc2dd251190 100644
+index 27dc02fd57dfe8942dc835d610b922dd7e66f309..a3926741a46756d8f7fdeb934685ba36122add76 100644
 --- a/net/minecraft/world/level/Level.java
 +++ b/net/minecraft/world/level/Level.java
 @@ -143,6 +143,12 @@ public abstract class Level implements LevelAccessor, UUIDLookup<Entity>, AutoCl

@@ -28728,7 +28728,7 @@ index 8cc5c0716392ba06501542ff5cbe71ee43979e5d..09fd99c9cbd23b5f3c899bfb00c9b896
 +    // Paper end - block counting
  }
 diff --git a/net/minecraft/world/entity/Entity.java b/net/minecraft/world/entity/Entity.java
-index 17d9e4699e8e2ce934c25d34d7269bdda5c87d00..295d40341df325b3fb6f14164283863a5a96b8bf 100644
+index 990305f720cf0817a5b369c6454cd2c61b423bc7..b4392f9914d0a104d9e933c06ac72e5363510184 100644
 --- a/net/minecraft/world/entity/Entity.java
 +++ b/net/minecraft/world/entity/Entity.java
 @@ -147,7 +147,7 @@ import net.minecraft.world.waypoints.WaypointTransmitter;
@@ -28979,7 +28979,7 @@ index 17d9e4699e8e2ce934c25d34d7269bdda5c87d00..295d40341df325b3fb6f14164283863a
 
      public Entity(EntityType<?> entityType, Level level) {
          this.type = entityType;
-@@ -1378,35 +1484,77 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+@@ -1380,35 +1486,77 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
          return distance;
      }
 
@@ -29081,7 +29081,7 @@ index 17d9e4699e8e2ce934c25d34d7269bdda5c87d00..295d40341df325b3fb6f14164283863a
      }
 
      private static float[] collectCandidateStepUpHeights(AABB box, List<VoxelShape> colliders, float deltaY, float maxUpStep) {
-@@ -2680,21 +2828,110 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+@@ -2682,21 +2830,110 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
      }
 
      public boolean isInWall() {
@@ -29203,7 +29203,7 @@ index 17d9e4699e8e2ce934c25d34d7269bdda5c87d00..295d40341df325b3fb6f14164283863a
      }
 
      public InteractionResult interact(Player player, InteractionHand hand) {
-@@ -4290,15 +4527,17 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+@@ -4292,15 +4529,17 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
      }
 
      public Iterable<Entity> getIndirectPassengers() {
@@ -29229,7 +29229,7 @@ index 17d9e4699e8e2ce934c25d34d7269bdda5c87d00..295d40341df325b3fb6f14164283863a
      }
 
      public int countPlayerPassengers() {
-@@ -4441,77 +4680,136 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+@@ -4443,77 +4682,136 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
          return Mth.lerp(partialTick, this.yRotO, this.yRot);
      }
 
@@ -29420,7 +29420,7 @@ index 17d9e4699e8e2ce934c25d34d7269bdda5c87d00..295d40341df325b3fb6f14164283863a
 
      public boolean touchingUnloadedChunk() {
          AABB aabb = this.getBoundingBox().inflate(1.0);
-@@ -4666,6 +4964,15 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+@@ -4668,6 +4966,15 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
      }
 
      public final void setPosRaw(double x, double y, double z, boolean forceBoundingBoxUpdate) {
@@ -29436,7 +29436,7 @@ index 17d9e4699e8e2ce934c25d34d7269bdda5c87d00..295d40341df325b3fb6f14164283863a
          if (!checkPosition(this, x, y, z)) {
              return;
          }
-@@ -4817,6 +5124,12 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+@@ -4819,6 +5126,12 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
 
      @Override
      public final void setRemoved(Entity.RemovalReason removalReason, @Nullable org.bukkit.event.entity.EntityRemoveEvent.Cause cause) { // CraftBukkit - add Bukkit remove cause
@@ -29449,7 +29449,7 @@ index 17d9e4699e8e2ce934c25d34d7269bdda5c87d00..295d40341df325b3fb6f14164283863a
          org.bukkit.craftbukkit.event.CraftEventFactory.callEntityRemoveEvent(this, cause); // CraftBukkit
          final boolean alreadyRemoved = this.removalReason != null; // Paper - Folia schedulers
          if (this.removalReason == null) {
-@@ -4827,7 +5140,7 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+@@ -4829,7 +5142,7 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
              this.stopRiding();
          }
 
@@ -29458,7 +29458,7 @@ index 17d9e4699e8e2ce934c25d34d7269bdda5c87d00..295d40341df325b3fb6f14164283863a
          this.levelCallback.onRemove(removalReason);
          this.onRemoval(removalReason);
          // Paper start - Folia schedulers
-@@ -4861,7 +5174,7 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+@@ -4863,7 +5176,7 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
      public boolean shouldBeSaved() {
          return (this.removalReason == null || this.removalReason.shouldSave())
              && !this.isPassenger()

@@ -67,10 +67,10 @@ index fd93b0c887420789276ebf92023d3e02b99cc1c9..9243bb11e3f968d0bf0eb2e3dc9295c0
          io.papermc.paper.adventure.providers.ClickCallbackProviderImpl.DIALOG_CLICK_MANAGER.handleQueue(this.tickCount); // Paper
          profilerFiller.push("commandFunctions");
 diff --git a/net/minecraft/world/entity/Entity.java b/net/minecraft/world/entity/Entity.java
-index 295d40341df325b3fb6f14164283863a5a96b8bf..9a102b2c58446bd0aac5bd7f00e647f0270e7983 100644
+index b4392f9914d0a104d9e933c06ac72e5363510184..8e92d02c5a4b2040e9e351454d817409bfa1840b 100644
 --- a/net/minecraft/world/entity/Entity.java
 +++ b/net/minecraft/world/entity/Entity.java
-@@ -5164,6 +5164,11 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+@@ -5166,6 +5166,11 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
          this.getBukkitEntity().taskScheduler.retire();
      }
      // Paper end - Folia schedulers

@@ -0,0 +1,32 @@
+--- a/net/minecraft/server/commands/data/EntityDataAccessor.java
++++ b/net/minecraft/server/commands/data/EntityDataAccessor.java
+@@ -4,7 +_,9 @@
+ import com.mojang.brigadier.context.CommandContext;
+ import com.mojang.brigadier.exceptions.CommandSyntaxException;
+ import com.mojang.brigadier.exceptions.SimpleCommandExceptionType;
++import com.mojang.serialization.Codec;
+ import com.mojang.logging.LogUtils;
++import java.util.List;
+ import java.util.Locale;
+ import java.util.UUID;
+ import java.util.function.Function;
+@@ -39,6 +_,7 @@
+             return builder.then(Commands.literal("entity").then(action.apply(Commands.argument(argumentName, EntityArgument.entity()))));
+         }
+     };
++    private static final Codec<List<String>> TAG_LIST_CODEC = Codec.STRING.sizeLimitedListOf(1024); // Paper - add ScoreboardTagsChangeEvent
+     private final Entity entity;
+
+     public EntityDataAccessor(Entity entity) {
+@@ -54,6 +_,11 @@
+
+             try (ProblemReporter.ScopedCollector scopedCollector = new ProblemReporter.ScopedCollector(this.entity.problemPath(), LOGGER)) {
+                 this.entity.load(TagValueInput.create(scopedCollector, this.entity.registryAccess(), other));
++                // Paper start - add ScoreboardTagsChangeEvent
++                other.read("Tags", TAG_LIST_CODEC).ifPresent(tags -> {
++                    org.bukkit.craftbukkit.event.CraftEventFactory.callScoreboardTagsChangeEvent(this.entity, tags, io.papermc.paper.event.entity.ScoreboardTagsChangeEvent.Change.SET);
++                });
++                // Paper end - add ScoreboardTagsChangeEvent
+                 this.entity.setUUID(uuid);
+             }
+         }
@@ -197,16 +197,18 @@
      public boolean isSpectator() {
          return false;
      }
-@@ -362,7 +_,7 @@
+@@ -362,20 +_,28 @@
      }
 
      public boolean addTag(String tag) {
 -        return this.tags.size() < 1024 && this.tags.add(tag);
++        org.bukkit.craftbukkit.event.CraftEventFactory.callScoreboardTagsChangeEvent(this, tag, io.papermc.paper.event.entity.ScoreboardTagsChangeEvent.Change.ADD); // Paper - add ScoreboardTagsChangeEvent
 +        return this.tags.add(tag); // Paper - fully limit tag size - replace set impl
      }
 
      public boolean removeTag(String tag) {
-@@ -370,12 +_,18 @@
++        org.bukkit.craftbukkit.event.CraftEventFactory.callScoreboardTagsChangeEvent(this, tag, io.papermc.paper.event.entity.ScoreboardTagsChangeEvent.Change.REMOVE); // Paper - add ScoreboardTagsChangeEvent
+         return this.tags.remove(tag);
      }
 
      public void kill(ServerLevel level) {
@@ -848,7 +850,7 @@
              Vec2 vec2 = input.read("Rotation", Vec2.CODEC).orElse(Vec2.ZERO);
              this.setDeltaMovement(Math.abs(vec31.x) > 10.0 ? 0.0 : vec31.x, Math.abs(vec31.y) > 10.0 ? 0.0 : vec31.y, Math.abs(vec31.z) > 10.0 ? 0.0 : vec31.z);
              this.hasImpulse = true;
-@@ -1988,7 +_,20 @@
+@@ -1988,10 +_,23 @@
                  this.setNoGravity(input.getBooleanOr("NoGravity", false));
                  this.setGlowingTag(input.getBooleanOr("Glowing", false));
                  this.setTicksFrozen(input.getIntOr("TicksFrozen", 0));
@@ -869,7 +871,11 @@
 +                // Paper end
                  this.customData = input.read("data", CustomData.CODEC).orElse(CustomData.EMPTY);
                  this.tags.clear();
-                 input.read("Tags", TAG_LIST_CODEC).ifPresent(this.tags::addAll);
+-                input.read("Tags", TAG_LIST_CODEC).ifPresent(this.tags::addAll);
++                input.read("Tags", TAG_LIST_CODEC).ifPresent(tags::addAll);
+                 this.readAdditionalSaveData(input);
+                 if (this.repositionEntityAfterLoad()) {
+                     this.reapplyPosition();
 @@ -1999,6 +_,59 @@
              } else {
                  throw new IllegalStateException("Entity has invalid rotation");

@@ -18,12 +18,12 @@
 import io.papermc.paper.connection.HorriblePlayerLoginEventHack;
 import io.papermc.paper.connection.PlayerConnection;
 import io.papermc.paper.event.connection.PlayerConnectionValidateLoginEvent;
+import io.papermc.paper.event.entity.ScoreboardTagsChangeEvent;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
 import net.minecraft.network.Connection;
 import net.minecraft.network.chat.Component;
 import net.minecraft.network.protocol.game.ServerboundContainerClosePacket;
-import net.minecraft.resources.ResourceLocation;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.server.level.ServerPlayer;
@@ -2115,4 +2115,16 @@ public static Component handleLoginResult(PlayerList.LoginResult result, PlayerC
 
         return disconnectReason;
     }
+
+    // Paper start - add ScoreboardTagsChangeEvent
+    public static ScoreboardTagsChangeEvent callScoreboardTagsChangeEvent(Entity entity, List<String> tags, ScoreboardTagsChangeEvent.Change change) {
+        final var event = new ScoreboardTagsChangeEvent(entity.getBukkitEntity(), tags, change);
+        Bukkit.getPluginManager().callEvent(event);
+        return event;
+    }
+
+    public static ScoreboardTagsChangeEvent callScoreboardTagsChangeEvent(Entity entity, String tag, ScoreboardTagsChangeEvent.Change change) {
+        return callScoreboardTagsChangeEvent(entity, List.of(tag), change);
+    }
+    // Paper end - add ScoreboardTagsChangeEvent
 }