call transient events and finalize migration

paper-api/src/main/java/com/destroystokyo/paper/event/block/AnvilDamagedEvent.java

@@ -6,96 +6,55 @@ import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.inventory.InventoryEvent;
 import org.bukkit.inventory.AnvilInventory;
-import org.bukkit.inventory.InventoryView;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 
 /**
  * Called when an anvil is damaged from being used
  */
-@NullMarked
-public class AnvilDamagedEvent extends InventoryEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private DamageState damageState;
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public AnvilDamagedEvent(final InventoryView inventory, final @Nullable BlockData blockData) {
-        super(inventory);
-        this.damageState = DamageState.getState(blockData);
-    }
+public interface AnvilDamagedEvent extends InventoryEvent, Cancellable {
 
     @Override
-    public AnvilInventory getInventory() {
-        return (AnvilInventory) super.getInventory();
-    }
+    AnvilInventory getInventory();
 
     /**
      * Gets the new state of damage on the anvil
      *
      * @return Damage state
      */
-    public DamageState getDamageState() {
-        return this.damageState;
-    }
+    DamageState getDamageState();
 
     /**
      * Sets the new state of damage on the anvil
      *
      * @param damageState Damage state
      */
-    public void setDamageState(final DamageState damageState) {
-        this.damageState = damageState;
-    }
+    void setDamageState(DamageState damageState);
 
     /**
      * Gets if anvil is breaking on this use
      *
      * @return {@code true} if breaking
      */
-    public boolean isBreaking() {
-        return this.damageState == DamageState.BROKEN;
-    }
+    boolean isBreaking();
 
     /**
      * Sets if anvil is breaking on this use
      *
      * @param breaking {@code true} if breaking
      */
-    public void setBreaking(final boolean breaking) {
-        if (breaking) {
-            this.damageState = DamageState.BROKEN;
-        } else if (this.damageState == DamageState.BROKEN) {
-            this.damageState = DamageState.DAMAGED;
+    void setBreaking(boolean breaking);
+
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
         }
-    }
-
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+        return Holder.HANDLER_LIST;
     }
 
     /**
      * Represents the amount of damage on an anvil block
      */
-    public enum DamageState {
+    enum DamageState {
         FULL(Material.ANVIL),
         CHIPPED(Material.CHIPPED_ANVIL),
         DAMAGED(Material.DAMAGED_ANVIL),

paper-api/src/main/java/com/destroystokyo/paper/event/block/BeaconEffectEvent.java

@@ -1,88 +1,50 @@
 package com.destroystokyo.paper.event.block;
 
-import org.bukkit.block.Block;
 import org.bukkit.entity.Player;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.block.BlockEvent;
+import org.bukkit.event.player.PlayerEvent;
 import org.bukkit.potion.PotionEffect;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Called when a beacon effect is being applied to a player.
  */
-@NullMarked
-public class BeaconEffectEvent extends BlockEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final Player player;
-    private final boolean primary;
-    private PotionEffect effect;
-
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public BeaconEffectEvent(final Block beacon, final PotionEffect effect, final Player player, final boolean primary) {
-        super(beacon);
-        this.effect = effect;
-        this.player = player;
-        this.primary = primary;
-    }
+public interface BeaconEffectEvent extends BlockEvent, PlayerEvent, Cancellable {
 
     /**
      * Gets the potion effect being applied.
      *
      * @return Potion effect
      */
-    public PotionEffect getEffect() {
-        return this.effect;
-    }
+    PotionEffect getEffect();
 
     /**
      * Sets the potion effect that will be applied.
      *
      * @param effect Potion effect
      */
-    public void setEffect(final PotionEffect effect) {
-        this.effect = effect;
-    }
+    void setEffect(PotionEffect effect);
 
     /**
      * Gets the player who the potion effect is being applied to.
      *
      * @return Affected player
      */
-    public Player getPlayer() {
-        return this.player;
-    }
+    @Override
+    Player getPlayer();
 
     /**
      * Gets whether the effect is a primary beacon effect.
      *
      * @return {@code true} if this event represents a primary effect
      */
-    public boolean isPrimary() {
-        return this.primary;
-    }
+    boolean isPrimary();
 
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/block/BlockDestroyEvent.java

@@ -1,12 +1,9 @@
 package com.destroystokyo.paper.event.block;
 
-import org.bukkit.block.Block;
 import org.bukkit.block.data.BlockData;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.block.BlockExpEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Fired anytime the server intends to 'destroy' a block through some triggering reason.
@@ -18,103 +15,65 @@ import org.jspecify.annotations.NullMarked;
  * <p>
  * Events such as leaves decaying, pistons retracting (where the block is moving), does NOT fire this event.
  */
-@NullMarked
-public class BlockDestroyEvent extends BlockExpEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final BlockData newState;
-    private boolean willDrop;
-    private boolean playEffect = true;
-    private BlockData effectBlock;
-
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public BlockDestroyEvent(final Block block, final BlockData newState, final BlockData effectBlock, final int xp, final boolean willDrop) {
-        super(block, xp);
-        this.newState = newState;
-        this.effectBlock = effectBlock;
-        this.willDrop = willDrop;
-    }
+public interface BlockDestroyEvent extends BlockExpEvent, Cancellable {
 
     /**
      * Gets the effect that will be played when the block is broken.
      *
      * @return block break effect
      */
-    public BlockData getEffectBlock() {
-        return this.effectBlock;
-    }
+    BlockData getEffectBlock();
 
     /**
      * Sets the effect that will be played when the block is broken.
-     * Note: {@link BlockDestroyEvent#playEffect()} must be {@code true} in order for this effect to be
+     * Note: {@link #playEffect()} must be {@code true} in order for this effect to be
      * played.
      *
      * @param effectBlock block effect
      */
-    public void setEffectBlock(final BlockData effectBlock) {
-        this.effectBlock = effectBlock.clone();
-    }
+    void setEffectBlock(BlockData effectBlock);
 
     /**
      * @return The new state of this block (Air, or a Fluid type)
      */
-    public BlockData getNewState() {
-        return this.newState.clone();
-    }
+    BlockData getNewState();
 
     /**
      * @return If the server is going to drop the block in question with this destroy event
      */
-    public boolean willDrop() {
-        return this.willDrop;
-    }
+    boolean willDrop();
 
     /**
      * @param willDrop If the server is going to drop the block in question with this destroy event
      */
-    public void setWillDrop(final boolean willDrop) {
-        this.willDrop = willDrop;
-    }
+    void setWillDrop(boolean willDrop);
 
     /**
      * @return If the server is going to play the sound effect for this destruction
      */
-    public boolean playEffect() {
-        return this.playEffect;
-    }
+    boolean playEffect();
 
     /**
      * @param playEffect If the server should play the sound effect for this destruction
      */
-    public void setPlayEffect(final boolean playEffect) {
-        this.playEffect = playEffect;
-    }
+    void setPlayEffect(boolean playEffect);
 
     /**
      * @return If the event is cancelled, meaning the block will not be destroyed
      */
     @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
+    boolean isCancelled();
 
     /**
      * If the event is cancelled, the block will remain in its previous state.
      */
     @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
+    void setCancelled(boolean cancel);
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/block/TNTPrimeEvent.java

@@ -1,7 +1,6 @@
 package com.destroystokyo.paper.event.block;
 
 import org.bukkit.Material;
-import org.bukkit.block.Block;
 import org.bukkit.enchantments.Enchantment;
 import org.bukkit.entity.Entity;
 import org.bukkit.entity.Player;
@@ -9,9 +8,7 @@ import org.bukkit.entity.TNTPrimed;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.block.BlockEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.Nullable;
 
 /**
  * Called when TNT block is about to turn into {@link TNTPrimed}
@@ -23,31 +20,14 @@ import org.jetbrains.annotations.Nullable;
  * @deprecated use {@link org.bukkit.event.block.TNTPrimeEvent}
  */
 @Deprecated(forRemoval = true, since = "1.19.4")
-public class TNTPrimeEvent extends BlockEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    @NotNull private final PrimeReason reason;
-    @Nullable private final Entity primerEntity;
-
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public TNTPrimeEvent(@NotNull Block block, @NotNull PrimeReason reason, @Nullable Entity primerEntity) {
-        super(block);
-        this.reason = reason;
-        this.primerEntity = primerEntity;
-    }
+public interface TNTPrimeEvent extends BlockEvent, Cancellable {
 
     /**
      * Gets the TNT prime reason
      *
      * @return Prime reason
      */
-    @NotNull
-    public PrimeReason getReason() {
-        return this.reason;
-    }
+    PrimeReason getReason();
 
     /**
      * Gets the TNT primer {@link Entity}.
@@ -58,10 +38,7 @@ public class TNTPrimeEvent extends BlockEvent implements Cancellable {
      *
      * @return The {@link Entity} who primed the TNT
      */
-    @Nullable
-    public Entity getPrimerEntity() {
-        return this.primerEntity;
-    }
+    @Nullable Entity getPrimerEntity();
 
     /**
      * Gets whether spawning {@link TNTPrimed} should be cancelled or not
@@ -69,9 +46,7 @@ public class TNTPrimeEvent extends BlockEvent implements Cancellable {
      * @return Whether spawning {@link TNTPrimed} should be cancelled or not
      */
     @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
+    boolean isCancelled();
 
     /**
      * Sets whether to cancel spawning {@link TNTPrimed} or not
@@ -79,22 +54,16 @@ public class TNTPrimeEvent extends BlockEvent implements Cancellable {
      * @param cancel whether spawning {@link TNTPrimed} should be cancelled or not
      */
     @Override
-    public void setCancelled(boolean cancel) {
-        this.cancelled = cancel;
+    void setCancelled(boolean cancel);
+
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 
-    @NotNull
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    @NotNull
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
-    }
-
-    public enum PrimeReason {
+    enum PrimeReason {
         /**
          * When TNT prime was caused by other explosion (chain reaction)
          */

paper-api/src/main/java/com/destroystokyo/paper/event/block/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package com.destroystokyo.paper.event.block;
+
+import org.jspecify.annotations.NullMarked;

paper-api/src/main/java/com/destroystokyo/paper/event/brigadier/AsyncPlayerSendCommandsEvent.java

@@ -2,12 +2,9 @@ package com.destroystokyo.paper.event.brigadier;
 
 import com.mojang.brigadier.tree.RootCommandNode;
 import io.papermc.paper.command.brigadier.CommandSourceStack;
-import org.bukkit.Bukkit;
-import org.bukkit.entity.Player;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerEvent;
 import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Fired any time a Brigadier RootCommandNode is generated for a player to inform the client of commands.
@@ -30,45 +27,26 @@ import org.jspecify.annotations.NullMarked;
  * <p>This is a draft/experimental API and is subject to change.</p>
  */
 @ApiStatus.Experimental
-@NullMarked
-public class AsyncPlayerSendCommandsEvent<S extends CommandSourceStack> extends PlayerEvent {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final RootCommandNode<S> node;
-    private final boolean hasFiredAsync;
-
-    @ApiStatus.Internal
-    public AsyncPlayerSendCommandsEvent(final Player player, final RootCommandNode<S> node, final boolean hasFiredAsync) {
-        super(player, !Bukkit.isPrimaryThread());
-        this.node = node;
-        this.hasFiredAsync = hasFiredAsync;
-    }
+public interface AsyncPlayerSendCommandsEvent<S extends CommandSourceStack> extends PlayerEvent {
 
     /**
      * Gets the full Root Command Node being sent to the client, which is mutable.
      *
      * @return the root command node
      */
-    public RootCommandNode<S> getCommandNode() {
-        return this.node;
-    }
+    RootCommandNode<S> getCommandNode();
 
     /**
      * Gets if this event has already fired asynchronously.
      *
      * @return whether this event has already fired asynchronously
      */
-    public boolean hasFiredAsync() {
-        return this.hasFiredAsync;
-    }
+    boolean hasFiredAsync();
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/brigadier/AsyncPlayerSendSuggestionsEvent.java

@@ -1,67 +1,37 @@
 package com.destroystokyo.paper.event.brigadier;
 
 import com.mojang.brigadier.suggestion.Suggestions;
-import org.bukkit.Bukkit;
-import org.bukkit.entity.Player;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Called when sending {@link Suggestions} to the client. Will be called asynchronously if a plugin
  * marks the {@link com.destroystokyo.paper.event.server.AsyncTabCompleteEvent} event handled asynchronously,
  * otherwise called synchronously.
  */
-@NullMarked
-public class AsyncPlayerSendSuggestionsEvent extends PlayerEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private Suggestions suggestions;
-    private final String buffer;
-
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public AsyncPlayerSendSuggestionsEvent(final Player player, final Suggestions suggestions, final String buffer) {
-        super(player, !Bukkit.isPrimaryThread());
-        this.suggestions = suggestions;
-        this.buffer = buffer;
-    }
+public interface AsyncPlayerSendSuggestionsEvent extends PlayerEvent, Cancellable {
 
     /**
      * Gets the input buffer sent to request these suggestions.
      *
      * @return the input buffer
      */
-    public String getBuffer() {
-        return this.buffer;
-    }
+    String getBuffer();
 
     /**
      * Gets the suggestions to be sent to client.
      *
      * @return the suggestions
      */
-    public Suggestions getSuggestions() {
-        return this.suggestions;
-    }
+    Suggestions getSuggestions();
 
     /**
      * Sets the suggestions to be sent to client.
      *
      * @param suggestions suggestions
      */
-    public void setSuggestions(final Suggestions suggestions) {
-        this.suggestions = suggestions;
-    }
-
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
+    void setSuggestions(Suggestions suggestions);
 
     /**
      * Cancels sending suggestions to the client.
@@ -69,16 +39,12 @@ public class AsyncPlayerSendSuggestionsEvent extends PlayerEvent implements Canc
      * {@inheritDoc}
      */
     @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
+    void setCancelled(boolean cancel);
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/brigadier/CommandRegisteredEvent.java

@@ -1,6 +1,7 @@
 package com.destroystokyo.paper.event.brigadier;
 
 import com.destroystokyo.paper.brigadier.BukkitBrigadierCommand;
+import com.destroystokyo.paper.brigadier.BukkitBrigadierCommandSource;
 import com.mojang.brigadier.tree.ArgumentCommandNode;
 import com.mojang.brigadier.tree.LiteralCommandNode;
 import com.mojang.brigadier.tree.RootCommandNode;
@@ -9,7 +10,6 @@ import org.bukkit.command.Command;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.server.ServerEvent;
-import org.jetbrains.annotations.NotNull;
 
 /**
  * Fired anytime the server synchronizes Bukkit commands to Brigadier.
@@ -22,37 +22,14 @@ import org.jetbrains.annotations.NotNull;
  */
 @Deprecated(since = "1.20.6")
 @Warning(reason = "This event has been superseded by the Commands API and will be removed in a future release. Listen to LifecycleEvents.COMMANDS instead.", value = true)
-public class CommandRegisteredEvent<S extends com.destroystokyo.paper.brigadier.BukkitBrigadierCommandSource> extends ServerEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final String commandLabel;
-    private final Command command;
-    private final com.destroystokyo.paper.brigadier.BukkitBrigadierCommand<S> brigadierCommand;
-    private final RootCommandNode<S> root;
-    private final ArgumentCommandNode<S, String> defaultArgs;
-    private LiteralCommandNode<S> literal;
-    private boolean rawCommand = false;
-
-    private boolean cancelled;
-
-    public CommandRegisteredEvent(String commandLabel, com.destroystokyo.paper.brigadier.BukkitBrigadierCommand<S> brigadierCommand, Command command, RootCommandNode<S> root, LiteralCommandNode<S> literal, ArgumentCommandNode<S, String> defaultArgs) {
-        this.commandLabel = commandLabel;
-        this.brigadierCommand = brigadierCommand;
-        this.command = command;
-        this.root = root;
-        this.literal = literal;
-        this.defaultArgs = defaultArgs;
-    }
+public interface CommandRegisteredEvent<S extends BukkitBrigadierCommandSource> extends ServerEvent, Cancellable {
 
     /**
      * Gets the command label of the {@link Command} being registered.
      *
      * @return the command label
      */
-    public String getCommandLabel() {
-        return this.commandLabel;
-    }
+    String getCommandLabel();
 
     /**
      * Gets the {@link BukkitBrigadierCommand} for the {@link Command} being registered. This can be used
@@ -62,46 +39,28 @@ public class CommandRegisteredEvent<S extends com.destroystokyo.paper.brigadier.
      *
      * @return the {@link BukkitBrigadierCommand}
      */
-    public BukkitBrigadierCommand<S> getBrigadierCommand() {
-        return this.brigadierCommand;
-    }
+    BukkitBrigadierCommand<S> getBrigadierCommand();
 
     /**
      * Gets the {@link Command} being registered.
      *
      * @return the {@link Command}
      */
-    public Command getCommand() {
-        return this.command;
-    }
+    Command getCommand();
 
     /**
      * Gets the {@link RootCommandNode} which is being registered to.
      *
      * @return the {@link RootCommandNode}
      */
-    public RootCommandNode<S> getRoot() {
-        return this.root;
-    }
-
-    /**
-     * Gets the Bukkit APIs default arguments node (greedy string), for if
-     * you wish to reuse it.
-     *
-     * @return default arguments node
-     */
-    public ArgumentCommandNode<S, String> getDefaultArgs() {
-        return this.defaultArgs;
-    }
+    RootCommandNode<S> getRoot();
 
     /**
      * Gets the {@link LiteralCommandNode} to be registered for the {@link Command}.
      *
      * @return the {@link LiteralCommandNode}
      */
-    public LiteralCommandNode<S> getLiteral() {
-        return this.literal;
-    }
+    LiteralCommandNode<S> getLiteral();
 
     /**
      * Sets the {@link LiteralCommandNode} used to register this command. The default literal is mutable, so
@@ -109,9 +68,15 @@ public class CommandRegisteredEvent<S extends com.destroystokyo.paper.brigadier.
      *
      * @param literal new node
      */
-    public void setLiteral(LiteralCommandNode<S> literal) {
-        this.literal = literal;
-    }
+    void setLiteral(LiteralCommandNode<S> literal);
+
+    /**
+     * Gets the Bukkit APIs default arguments node (greedy string), for if
+     * you wish to reuse it.
+     *
+     * @return default arguments node
+     */
+    ArgumentCommandNode<S, String> getDefaultArgs();
 
     /**
      * Gets whether this command should is treated as "raw".
@@ -119,9 +84,7 @@ public class CommandRegisteredEvent<S extends com.destroystokyo.paper.brigadier.
      * @see #setRawCommand(boolean)
      * @return whether this command is treated as "raw"
      */
-    public boolean isRawCommand() {
-        return this.rawCommand;
-    }
+    boolean isRawCommand();
 
     /**
      * Sets whether this command should be treated as "raw".
@@ -135,14 +98,7 @@ public class CommandRegisteredEvent<S extends com.destroystokyo.paper.brigadier.
      *
      * @param rawCommand whether this command should be treated as "raw"
      */
-    public void setRawCommand(final boolean rawCommand) {
-        this.rawCommand = rawCommand;
-    }
-
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
+    void setRawCommand(boolean rawCommand);
 
     /**
      * Cancels registering this command to Brigadier, but will remain in Bukkit Command Map. Can be used to hide a
@@ -151,17 +107,12 @@ public class CommandRegisteredEvent<S extends com.destroystokyo.paper.brigadier.
      * {@inheritDoc}
      */
     @Override
-    public void setCancelled(boolean cancel) {
-        this.cancelled = cancel;
-    }
+    void setCancelled(boolean cancel);
 
-    @NotNull
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    @NotNull
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/brigadier/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package com.destroystokyo.paper.event.brigadier;
+
+import org.jspecify.annotations.NullMarked;

paper-api/src/main/java/com/destroystokyo/paper/event/entity/CreeperIgniteEvent.java

@@ -2,59 +2,18 @@ package com.destroystokyo.paper.event.entity;
 
 import io.papermc.paper.event.entity.EntityIgniteEvent;
 import org.bukkit.entity.Creeper;
-import org.bukkit.event.Cancellable;
-import org.bukkit.event.HandlerList;
-import org.bukkit.event.entity.EntityEvent;
-import org.checkerframework.checker.index.qual.Positive;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Called when a Creeper is ignited either by a
  * flint and steel, {@link Creeper#ignite()} or
  * {@link Creeper#setIgnited(boolean)}.
  */
-@NullMarked
-public class CreeperIgniteEvent extends EntityIgniteEvent {
-
-    private boolean ignited;
-
-    @ApiStatus.Internal
-    public CreeperIgniteEvent(final Creeper creeper, final boolean ignited) {
-        super(creeper, creeper.getMaxFuseTicks());
-        this.ignited = ignited;
-    }
+public interface CreeperIgniteEvent extends EntityIgniteEvent {
 
     @Override
-    public Creeper getEntity() {
-        return (Creeper) super.getEntity();
-    }
+    Creeper getEntity();
 
-    public boolean isIgnited() {
-        return this.ignited;
-    }
+    boolean isIgnited();
 
-    public void setIgnited(final boolean ignited) {
-        this.ignited = ignited;
-    }
-
-    @Override
-    public @Positive int getFuseTime() {
-        return this.getEntity().getMaxFuseTicks();
-    }
-
-    @Override
-    public void setFuseTime(final @Positive int ticks) {
-        this.getEntity().setMaxFuseTicks(ticks);
-    }
-
-    @Override
-    public boolean isCancelled() {
-        return super.isCancelled();
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        super.setCancelled(cancel);
-    }
+    void setIgnited(boolean ignited);
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/EnderDragonFireballHitEvent.java

@@ -7,68 +7,35 @@ import org.bukkit.entity.LivingEntity;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.entity.EntityEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
+import org.jetbrains.annotations.Unmodifiable;
 
 /**
  * Fired when a DragonFireball collides with a block/entity and spawns an AreaEffectCloud
  */
-@NullMarked
-public class EnderDragonFireballHitEvent extends EntityEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final Collection<LivingEntity> targets;
-    private final AreaEffectCloud areaEffectCloud;
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public EnderDragonFireballHitEvent(final DragonFireball fireball, final Collection<LivingEntity> targets, final AreaEffectCloud areaEffectCloud) {
-        super(fireball);
-        this.targets = targets;
-        this.areaEffectCloud = areaEffectCloud;
-    }
+public interface EnderDragonFireballHitEvent extends EntityEvent, Cancellable {
 
     /**
      * The fireball involved in this event
      */
     @Override
-    public DragonFireball getEntity() {
-        return (DragonFireball) super.getEntity();
-    }
+    DragonFireball getEntity();
 
     /**
      * The living entities hit by fireball
      *
      * @return the targets
      */
-    public Collection<LivingEntity> getTargets() {
-        return this.targets;
-    }
+    @Unmodifiable Collection<LivingEntity> getTargets();
 
     /**
      * @return The area effect cloud spawned in this collision
      */
-    public AreaEffectCloud getAreaEffectCloud() {
-        return this.areaEffectCloud;
-    }
+    AreaEffectCloud getAreaEffectCloud();
 
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/EnderDragonFlameEvent.java

@@ -5,57 +5,27 @@ import org.bukkit.entity.EnderDragon;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.entity.EntityEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Fired when an EnderDragon spawns an AreaEffectCloud by shooting flames
  */
-@NullMarked
-public class EnderDragonFlameEvent extends EntityEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final AreaEffectCloud areaEffectCloud;
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public EnderDragonFlameEvent(final EnderDragon enderDragon, final AreaEffectCloud areaEffectCloud) {
-        super(enderDragon);
-        this.areaEffectCloud = areaEffectCloud;
-    }
+public interface EnderDragonFlameEvent extends EntityEvent, Cancellable {
 
     /**
      * The enderdragon involved in this event
      */
     @Override
-    public EnderDragon getEntity() {
-        return (EnderDragon) super.getEntity();
-    }
+    EnderDragon getEntity();
 
     /**
      * @return The area effect cloud spawned in this collision
      */
-    public AreaEffectCloud getAreaEffectCloud() {
-        return this.areaEffectCloud;
-    }
+    AreaEffectCloud getAreaEffectCloud();
 
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/EnderDragonShootFireballEvent.java

@@ -5,57 +5,27 @@ import org.bukkit.entity.EnderDragon;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.entity.EntityEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Fired when an EnderDragon shoots a fireball
  */
-@NullMarked
-public class EnderDragonShootFireballEvent extends EntityEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final DragonFireball fireball;
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public EnderDragonShootFireballEvent(final EnderDragon entity, final DragonFireball fireball) {
-        super(entity);
-        this.fireball = fireball;
-    }
+public interface EnderDragonShootFireballEvent extends EntityEvent, Cancellable {
 
     /**
      * The enderdragon shooting the fireball
      */
     @Override
-    public EnderDragon getEntity() {
-        return (EnderDragon) super.getEntity();
-    }
+    EnderDragon getEntity();
 
     /**
      * @return The fireball being shot
      */
-    public DragonFireball getFireball() {
-        return this.fireball;
-    }
+    DragonFireball getFireball();
 
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/EndermanAttackPlayerEvent.java

@@ -28,8 +28,6 @@ import org.bukkit.entity.Player;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.entity.EntityEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Fired when an Enderman determines if it should attack a player or not.
@@ -37,19 +35,7 @@ import org.jspecify.annotations.NullMarked;
  * Starts off cancelled if the player is wearing a pumpkin head or is not looking
  * at the Enderman, according to Vanilla rules.
  */
-@NullMarked
-public class EndermanAttackPlayerEvent extends EntityEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final Player player;
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public EndermanAttackPlayerEvent(final Enderman entity, final Player player) {
-        super(entity);
-        this.player = player;
-    }
+public interface EndermanAttackPlayerEvent extends EntityEvent, Cancellable {
 
     /**
      * The enderman considering attacking
@@ -57,26 +43,20 @@ public class EndermanAttackPlayerEvent extends EntityEvent implements Cancellabl
      * @return The enderman considering attacking
      */
     @Override
-    public Enderman getEntity() {
-        return (Enderman) super.getEntity();
-    }
+    Enderman getEntity();
 
     /**
      * The player the Enderman is considering attacking
      *
      * @return The player the Enderman is considering attacking
      */
-    public Player getPlayer() {
-        return this.player;
-    }
+    Player getPlayer();
 
     /**
      * @return If cancelled, the enderman will not attack
      */
     @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
+    boolean isCancelled();
 
     /**
      * {@inheritDoc}
@@ -84,16 +64,12 @@ public class EndermanAttackPlayerEvent extends EntityEvent implements Cancellabl
      * Cancels if the Enderman will attack this player
      */
     @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
+    void setCancelled(boolean cancel);
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/EndermanEscapeEvent.java

@@ -4,41 +4,18 @@ import org.bukkit.entity.Enderman;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.entity.EntityEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
-@NullMarked
-public class EndermanEscapeEvent extends EntityEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final Reason reason;
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public EndermanEscapeEvent(final Enderman entity, final Reason reason) {
-        super(entity);
-        this.reason = reason;
-    }
+public interface EndermanEscapeEvent extends EntityEvent, Cancellable {
 
     @Override
-    public Enderman getEntity() {
-        return (Enderman) super.getEntity();
-    }
+    Enderman getEntity();
 
     /**
      * Gets the reason the enderman is trying to escape.
      *
      * @return The reason
      */
-    public Reason getReason() {
-        return this.reason;
-    }
-
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
+    Reason getReason();
 
     /**
      * Cancels the escape.
@@ -48,20 +25,16 @@ public class EndermanEscapeEvent extends EntityEvent implements Cancellable {
      * innate immunities or damage behavior like arrows where the damage never happens.
      */
     @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
+    void setCancelled(boolean cancel);
+
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
-    }
-
-    public enum Reason {
+    enum Reason {
         /**
          * The enderman has stopped attacking and ran away
          */

paper-api/src/main/java/com/destroystokyo/paper/event/entity/EntityAddToWorldEvent.java

@@ -1,44 +1,28 @@
 package com.destroystokyo.paper.event.entity;
 
 import org.bukkit.World;
-import org.bukkit.entity.Entity;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.entity.CreatureSpawnEvent;
 import org.bukkit.event.entity.EntityEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
+import org.bukkit.event.world.WorldEvent;
 
 /**
  * Fired any time an entity is being added to the world for any reason (including a chunk loading).
  * <p>
  * Not to be confused with {@link CreatureSpawnEvent}
  */
-@NullMarked
-public class EntityAddToWorldEvent extends EntityEvent {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final World world;
-
-    @ApiStatus.Internal
-    public EntityAddToWorldEvent(final Entity entity, final World world) {
-        super(entity);
-        this.world = world;
-    }
+public interface EntityAddToWorldEvent extends EntityEvent, WorldEvent {
 
     /**
      * @return The world that the entity is being added to
      */
-    public World getWorld() {
-        return this.world;
-    }
-
     @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
+    World getWorld();
 
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/EntityJumpEvent.java

@@ -4,47 +4,21 @@ import org.bukkit.entity.LivingEntity;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.entity.EntityEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Called when an entity jumps
  * <p>
  * Cancelling the event will stop the entity from jumping
  */
-@NullMarked
-public class EntityJumpEvent extends EntityEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public EntityJumpEvent(final LivingEntity entity) {
-        super(entity);
-    }
+public interface EntityJumpEvent extends EntityEvent, Cancellable {
 
     @Override
-    public LivingEntity getEntity() {
-        return (LivingEntity) super.getEntity();
-    }
+    LivingEntity getEntity();
 
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/EntityKnockbackByEntityEvent.java

@@ -1,52 +1,33 @@
 package com.destroystokyo.paper.event.entity;
 
-import io.papermc.paper.event.entity.EntityKnockbackEvent;
 import io.papermc.paper.event.entity.EntityPushedByEntityAttackEvent;
 import org.bukkit.entity.Entity;
 import org.bukkit.entity.LivingEntity;
-import org.bukkit.util.Vector;
 import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Fired when an Entity is knocked back by the hit of another Entity. The acceleration
  * vector can be modified. If this event is cancelled, the entity is not knocked back.
  */
-@NullMarked
-public class EntityKnockbackByEntityEvent extends EntityPushedByEntityAttackEvent {
-
-    private final float knockbackStrength;
-
-    @ApiStatus.Internal
-    public EntityKnockbackByEntityEvent(final LivingEntity entity, final Entity hitBy, final EntityKnockbackEvent.Cause cause, final float knockbackStrength, final Vector knockback) {
-        super(entity, cause, hitBy, knockback);
-        this.knockbackStrength = knockbackStrength;
-    }
+public interface EntityKnockbackByEntityEvent extends EntityPushedByEntityAttackEvent {
 
     /**
      * @return the entity which was knocked back
      */
     @Override
-    public LivingEntity getEntity() {
-        return (LivingEntity) super.getEntity();
-    }
+    LivingEntity getEntity();
 
     /**
      * @return the original knockback strength.
      * @apiNote this value doesn't necessarily relate to {@link #getKnockback()}.
      */
     @ApiStatus.Obsolete(since = "1.20.6")
-    public float getKnockbackStrength() {
-        return this.knockbackStrength;
-    }
+    float getKnockbackStrength();
 
     /**
      * Gets the causing entity. Same as {@link #getPushedBy()}.
      *
      * @return the Entity which hit
      */
-    public Entity getHitBy() {
-        return super.getPushedBy();
-    }
-
+    Entity getHitBy();
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/EntityPathfindEvent.java

@@ -5,8 +5,6 @@ import org.bukkit.entity.Entity;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.entity.EntityEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 
 /**
@@ -15,21 +13,7 @@ import org.jspecify.annotations.Nullable;
  * This event does not fire for the entities actual movement. Only when it
  * is choosing to start moving to a location.
  */
-@NullMarked
-public class EntityPathfindEvent extends EntityEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final @Nullable Entity targetEntity;
-    private final Location location;
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public EntityPathfindEvent(final Entity entity, final Location location, final @Nullable Entity targetEntity) {
-        super(entity);
-        this.targetEntity = targetEntity;
-        this.location = location;
-    }
+public interface EntityPathfindEvent extends EntityEvent, Cancellable {
 
     /**
      * The Entity that is pathfinding.
@@ -37,9 +21,7 @@ public class EntityPathfindEvent extends EntityEvent implements Cancellable {
      * @return The Entity that is pathfinding.
      */
     @Override
-    public Entity getEntity() {
-        return this.entity;
-    }
+    Entity getEntity();
 
     /**
      * If the Entity is trying to pathfind to an entity, this is the entity in relation.
@@ -48,9 +30,7 @@ public class EntityPathfindEvent extends EntityEvent implements Cancellable {
      *
      * @return The entity target or {@code null}
      */
-    public @Nullable Entity getTargetEntity() {
-        return this.targetEntity;
-    }
+    @Nullable Entity getTargetEntity();
 
     /**
      * The Location of where the entity is about to move to.
@@ -59,26 +39,25 @@ public class EntityPathfindEvent extends EntityEvent implements Cancellable {
      *
      * @return Location of where the entity is trying to pathfind to.
      */
-    public Location getLoc() {
-        return this.location.clone();
+    Location getTargetLocation();
+
+    /**
+     * The Location of where the entity is about to move to.
+     * <br>
+     * Note that if the target happened to of been an entity
+     *
+     * @return Location of where the entity is trying to pathfind to.
+     * @deprecated use {@link #getTargetLocation()}
+     */
+    @Deprecated(forRemoval = true)
+    default Location getLoc() {
+        return this.getTargetLocation();
     }
 
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/EntityRemoveFromWorldEvent.java

@@ -1,42 +1,26 @@
 package com.destroystokyo.paper.event.entity;
 
 import org.bukkit.World;
-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 org.bukkit.event.world.WorldEvent;
 
 /**
  * Fired any time an entity is being removed from a world for any reason (including a chunk unloading).
  * Note: The entity is updated prior to this event being called, as such, the entity's world may not be equal to {@link #getWorld()}.
  */
-@NullMarked
-public class EntityRemoveFromWorldEvent extends EntityEvent {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final World world;
-
-    @ApiStatus.Internal
-    public EntityRemoveFromWorldEvent(final Entity entity, final World world) {
-        super(entity);
-        this.world = world;
-    }
+public interface EntityRemoveFromWorldEvent extends EntityEvent, WorldEvent {
 
     /**
      * @return The world that the entity is being removed from
      */
-    public World getWorld() {
-        return this.world;
-    }
-
     @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
+    World getWorld();
 
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/EntityTeleportEndGatewayEvent.java

@@ -1,33 +1,17 @@
 package com.destroystokyo.paper.event.entity;
 
-import org.bukkit.Location;
 import org.bukkit.block.EndGateway;
-import org.bukkit.entity.Entity;
 import org.bukkit.event.entity.EntityTeleportEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Fired any time an entity attempts to teleport in an end gateway
  */
-@NullMarked
-public class EntityTeleportEndGatewayEvent extends EntityTeleportEvent {
-
-    private final EndGateway gateway;
-
-    @ApiStatus.Internal
-    public EntityTeleportEndGatewayEvent(final Entity entity, final Location from, final Location to, final EndGateway gateway) {
-        super(entity, from, to);
-        this.gateway = gateway;
-    }
+public interface EntityTeleportEndGatewayEvent extends EntityTeleportEvent {
 
     /**
      * The gateway triggering the teleport
      *
      * @return EndGateway used
      */
-    public EndGateway getGateway() {
-        return this.gateway;
-    }
-
+    EndGateway getGateway();
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/EntityZapEvent.java

@@ -1,65 +1,35 @@
 package com.destroystokyo.paper.event.entity;
 
-import java.util.Collections;
 import org.bukkit.entity.Entity;
 import org.bukkit.entity.LightningStrike;
-import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.entity.EntityTransformEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Fired when lightning strikes an entity
  */
-@NullMarked
-public class EntityZapEvent extends EntityTransformEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final LightningStrike bolt;
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public EntityZapEvent(final Entity entity, final LightningStrike bolt, final Entity replacementEntity) {
-        super(entity, Collections.singletonList(replacementEntity), TransformReason.LIGHTNING);
-        this.bolt = bolt;
-    }
+public interface EntityZapEvent extends EntityTransformEvent {
 
     /**
      * Gets the lightning bolt that is striking the entity.
      *
      * @return The lightning bolt responsible for this event
      */
-    public LightningStrike getBolt() {
-        return this.bolt;
-    }
+    LightningStrike getBolt();
 
     /**
      * Gets the entity that will replace the struck entity.
      *
      * @return The entity that will replace the struck entity
      */
-    public Entity getReplacementEntity() {
-        return super.getTransformedEntity();
+    default Entity getReplacementEntity() {
+        return this.getTransformedEntity();
     }
 
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/ExperienceOrbMergeEvent.java

@@ -27,62 +27,32 @@ import org.bukkit.entity.ExperienceOrb;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.entity.EntityEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Fired anytime the server is about to merge 2 experience orbs into one
  */
-@NullMarked
-public class ExperienceOrbMergeEvent extends EntityEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final ExperienceOrb mergeTarget;
-    private final ExperienceOrb mergeSource;
-
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public ExperienceOrbMergeEvent(final ExperienceOrb mergeTarget, final ExperienceOrb mergeSource) {
-        super(mergeTarget);
-        this.mergeTarget = mergeTarget;
-        this.mergeSource = mergeSource;
-    }
+public interface ExperienceOrbMergeEvent extends EntityEvent, Cancellable {
 
     /**
-     * @return The orb that will absorb the other experience orb
+     * {@return the orb that will absorb the other experience orb}
      */
-    public ExperienceOrb getMergeTarget() {
-        return this.mergeTarget;
-    }
+    ExperienceOrb getMergeTarget();
 
     /**
-     * @return The orb that is subject to being removed and merged into the target orb
+     * {@return the orb that is subject to being removed and merged into the target orb}
      */
-    public ExperienceOrb getMergeSource() {
-        return this.mergeSource;
-    }
-
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
+    ExperienceOrb getMergeSource();
 
     /**
      * @param cancel {@code true} if you wish to cancel this event, and prevent the orbs from merging
      */
     @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
+    void setCancelled(boolean cancel);
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/PhantomPreSpawnEvent.java

@@ -1,32 +1,16 @@
 package com.destroystokyo.paper.event.entity;
 
-import org.bukkit.Location;
 import org.bukkit.entity.Entity;
-import org.bukkit.entity.EntityType;
-import org.bukkit.event.entity.CreatureSpawnEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Called when a phantom is spawned for an exhausted player
  */
-@NullMarked
-public class PhantomPreSpawnEvent extends PreCreatureSpawnEvent {
-
-    private final Entity entity;
-
-    @ApiStatus.Internal
-    public PhantomPreSpawnEvent(final Location location, final Entity entity, final CreatureSpawnEvent.SpawnReason reason) {
-        super(location, EntityType.PHANTOM, reason);
-        this.entity = entity;
-    }
+public interface PhantomPreSpawnEvent extends PreCreatureSpawnEvent {
 
     /**
      * Get the entity this phantom is spawning for
      *
      * @return the Entity
      */
-    public Entity getSpawningEntity() {
-        return this.entity;
-    }
+    Entity getSpawningEntity();
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/PlayerNaturallySpawnCreaturesEvent.java

@@ -1,65 +1,40 @@
 package com.destroystokyo.paper.event.entity;
 
-import org.bukkit.entity.Player;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Fired when the server is calculating what chunks to try to spawn monsters in every Monster Spawn Tick event
  */
-@NullMarked
-public class PlayerNaturallySpawnCreaturesEvent extends PlayerEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private byte radius;
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public PlayerNaturallySpawnCreaturesEvent(final Player player, final byte radius) {
-        super(player);
-        this.radius = radius;
-    }
+public interface PlayerNaturallySpawnCreaturesEvent extends PlayerEvent, Cancellable {
 
     /**
      * @return The radius of chunks around this player to be included in natural spawn selection
      */
-    public byte getSpawnRadius() {
-        return this.radius;
-    }
+    byte getSpawnRadius();
 
     /**
      * @param radius The radius of chunks around this player to be included in natural spawn selection
      */
-    public void setSpawnRadius(final byte radius) {
-        this.radius = radius;
-    }
+    void setSpawnRadius(byte radius);
 
     /**
      * @return If this player's chunks will be excluded from natural spawns
      */
     @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
+    boolean isCancelled();
 
     /**
      * @param cancel {@code true} if you wish to cancel this event, and not include this player's chunks for natural spawning
      */
     @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
+    void setCancelled(boolean cancel);
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/PreCreatureSpawnEvent.java

@@ -6,8 +6,6 @@ import org.bukkit.event.Cancellable;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.entity.CreatureSpawnEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * WARNING: This event only fires for a limited number of cases, and not for every case that {@link CreatureSpawnEvent} does.
@@ -19,52 +17,27 @@ import org.jspecify.annotations.NullMarked;
  * Currently: NATURAL and SPAWNER based reasons. <!-- Please submit a Pull Request for future additions. -->
  * Also, Plugins that replace Entity Registrations with their own custom entities might not fire this event.
  */
-@NullMarked
-public class PreCreatureSpawnEvent extends Event implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final Location location;
-    private final EntityType type;
-    private final CreatureSpawnEvent.SpawnReason reason;
-    private boolean shouldAbortSpawn;
-
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public PreCreatureSpawnEvent(final Location location, final EntityType type, final CreatureSpawnEvent.SpawnReason reason) {
-        this.location = location;
-        this.type = type;
-        this.reason = reason;
-    }
+public interface PreCreatureSpawnEvent extends Event, Cancellable {
 
     /**
      * @return The location this creature is being spawned at
      */
-    public Location getSpawnLocation() {
-        return this.location.clone();
-    }
+    Location getSpawnLocation();
 
     /**
      * @return The type of creature being spawned
      */
-    public EntityType getType() {
-        return this.type;
-    }
+    EntityType getType();
 
     /**
      * @return Reason this creature is spawning (ie, NATURAL vs SPAWNER)
      */
-    public CreatureSpawnEvent.SpawnReason getReason() {
-        return this.reason;
-    }
+    CreatureSpawnEvent.SpawnReason getReason();
 
     /**
      * @return If the spawn process should be aborted vs trying more attempts
      */
-    public boolean shouldAbortSpawn() {
-        return this.shouldAbortSpawn;
-    }
+    boolean shouldAbortSpawn();
 
     /**
      * Set this if you are more blanket blocking all types of these spawns, and wish to abort the spawn process from
@@ -72,17 +45,13 @@ public class PreCreatureSpawnEvent extends Event implements Cancellable {
      *
      * @param shouldAbortSpawn Set if the spawn process should be aborted vs trying more attempts
      */
-    public void setShouldAbortSpawn(final boolean shouldAbortSpawn) {
-        this.shouldAbortSpawn = shouldAbortSpawn;
-    }
+    void setShouldAbortSpawn(boolean shouldAbortSpawn);
 
     /**
      * @return If the spawn of this creature is cancelled or not
      */
     @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
+    boolean isCancelled();
 
     /**
      * Cancelling this event is more efficient than cancelling {@link CreatureSpawnEvent}
@@ -90,16 +59,12 @@ public class PreCreatureSpawnEvent extends Event implements Cancellable {
      * @param cancel {@code true} if you wish to cancel this event, and abort the spawn of this creature
      */
     @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
+    void setCancelled(boolean cancel);
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/PreSpawnerSpawnEvent.java

@@ -1,10 +1,6 @@
 package com.destroystokyo.paper.event.entity;
 
 import org.bukkit.Location;
-import org.bukkit.entity.EntityType;
-import org.bukkit.event.entity.CreatureSpawnEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Called before an entity is spawned into a world by a spawner.
@@ -12,18 +8,7 @@ import org.jspecify.annotations.NullMarked;
  * This only includes the spawner's location and not the full BlockState snapshot for performance reasons.
  * If you really need it you have to get the spawner yourself.
  */
-@NullMarked
-public class PreSpawnerSpawnEvent extends PreCreatureSpawnEvent {
+public interface PreSpawnerSpawnEvent extends PreCreatureSpawnEvent {
 
-    private final Location spawnerLocation;
-
-    @ApiStatus.Internal
-    public PreSpawnerSpawnEvent(final Location location, final EntityType type, final Location spawnerLocation) {
-        super(location, type, CreatureSpawnEvent.SpawnReason.SPAWNER);
-        this.spawnerLocation = spawnerLocation;
-    }
-
-    public Location getSpawnerLocation() {
-        return this.spawnerLocation.clone();
-    }
+    Location getSpawnerLocation();
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/ProjectileCollideEvent.java

@@ -6,69 +6,36 @@ import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.entity.EntityDamageByEntityEvent;
 import org.bukkit.event.entity.EntityEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jetbrains.annotations.NotNull;
 
 /**
  * Called when a projectile collides with an entity
  * <p>
  * This event is called <b>before</b> {@link EntityDamageByEntityEvent}, and cancelling it will allow the projectile to continue flying
  *
- * @deprecated Deprecated, use {@link org.bukkit.event.entity.ProjectileHitEvent} and check if there is a hit entity
+ * @deprecated use {@link org.bukkit.event.entity.ProjectileHitEvent} and check if there is a hit entity
  */
 @Deprecated(since = "1.19.3")
-public class ProjectileCollideEvent extends EntityEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    @NotNull private final Entity collidedWith;
-
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public ProjectileCollideEvent(@NotNull Projectile projectile, @NotNull Entity collidedWith) {
-        super(projectile);
-        this.collidedWith = collidedWith;
-    }
+public interface ProjectileCollideEvent extends EntityEvent, Cancellable {
 
     /**
      * Get the projectile that collided
      *
      * @return the projectile that collided
      */
-    @NotNull
-    public Projectile getEntity() {
-        return (Projectile) super.getEntity();
-    }
+    @Override
+    Projectile getEntity();
 
     /**
      * Get the entity the projectile collided with
      *
      * @return the entity collided with
      */
-    @NotNull
-    public Entity getCollidedWith() {
-        return this.collidedWith;
-    }
+    Entity getCollidedWith();
 
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @NotNull
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
-    }
-
-    @NotNull
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/SkeletonHorseTrapEvent.java

@@ -6,52 +6,22 @@ import org.bukkit.entity.SkeletonHorse;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.entity.EntityEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Event called when a player gets close to a skeleton horse and triggers the lightning trap
  */
-@NullMarked
-public class SkeletonHorseTrapEvent extends EntityEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final List<HumanEntity> eligibleHumans;
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public SkeletonHorseTrapEvent(final SkeletonHorse horse, final List<HumanEntity> eligibleHumans) {
-        super(horse);
-        this.eligibleHumans = eligibleHumans;
-    }
+public interface SkeletonHorseTrapEvent extends EntityEvent, Cancellable {
 
     @Override
-    public SkeletonHorse getEntity() {
-        return (SkeletonHorse) super.getEntity();
-    }
+    SkeletonHorse getEntity();
 
-    public List<HumanEntity> getEligibleHumans() {
-        return this.eligibleHumans;
-    }
+    List<HumanEntity> getEligibleHumans();
 
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }
 

paper-api/src/main/java/com/destroystokyo/paper/event/entity/SlimeChangeDirectionEvent.java

@@ -1,41 +1,24 @@
 package com.destroystokyo.paper.event.entity;
 
-import org.bukkit.entity.AbstractCubeMob;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
-
 /**
  * Fired when a Slime decides to change its facing direction.
  * <p>
  * This event does not fire for the entity's actual movement. Only when it
  * is choosing to change direction.
  */
-@NullMarked
-public class SlimeChangeDirectionEvent extends SlimePathfindEvent {
-
-    private float yaw;
-
-    @ApiStatus.Internal
-    public SlimeChangeDirectionEvent(final AbstractCubeMob cubeMob, final float yaw) {
-        super(cubeMob);
-        this.yaw = yaw;
-    }
+public interface SlimeChangeDirectionEvent extends SlimePathfindEvent {
 
     /**
      * Get the new chosen yaw
      *
      * @return Chosen yaw
      */
-    public float getNewYaw() {
-        return this.yaw;
-    }
+    float getNewYaw();
 
     /**
      * Set the new chosen yaw
      *
      * @param yaw Chosen yaw
      */
-    public void setNewYaw(final float yaw) {
-        this.yaw = yaw;
-    }
+    void setNewYaw(float yaw);
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/SlimePathfindEvent.java

@@ -4,8 +4,6 @@ import org.bukkit.entity.AbstractCubeMob;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.entity.EntityEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Fired when a Slime decides to start pathfinding.
@@ -13,17 +11,7 @@ import org.jspecify.annotations.NullMarked;
  * This event does not fire for the entity's actual movement. Only when it
  * is choosing to start moving.
  */
-@NullMarked
-public class SlimePathfindEvent extends EntityEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public SlimePathfindEvent(final AbstractCubeMob cubeMob) {
-        super(cubeMob);
-    }
+public interface SlimePathfindEvent extends EntityEvent, Cancellable {
 
     /**
      * The Slime that is pathfinding.
@@ -31,26 +19,12 @@ public class SlimePathfindEvent extends EntityEvent implements Cancellable {
      * @return The Slime that is pathfinding.
      */
     @Override
-    public AbstractCubeMob getEntity() {
-        return (AbstractCubeMob) super.getEntity();
-    }
+    AbstractCubeMob getEntity();
 
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/SlimeSwimEvent.java

@@ -1,20 +1,10 @@
 package com.destroystokyo.paper.event.entity;
 
-import org.bukkit.entity.AbstractCubeMob;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
-
 /**
  * Fired when a Slime decides to start jumping while swimming in water/lava.
  * <p>
  * This event does not fire for the entity's actual movement. Only when it
  * is choosing to start jumping.
  */
-@NullMarked
-public class SlimeSwimEvent extends SlimeWanderEvent {
-
-    @ApiStatus.Internal
-    public SlimeSwimEvent(final AbstractCubeMob cubeMob) {
-        super(cubeMob);
-    }
+public interface SlimeSwimEvent extends SlimeWanderEvent {
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/SlimeTargetLivingEntityEvent.java

@@ -1,9 +1,6 @@
 package com.destroystokyo.paper.event.entity;
 
-import org.bukkit.entity.AbstractCubeMob;
 import org.bukkit.entity.LivingEntity;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Fired when a Slime decides to change direction to target a LivingEntity.
@@ -11,23 +8,12 @@ import org.jspecify.annotations.NullMarked;
  * This event does not fire for the entity's actual movement. Only when it
  * is choosing to start moving.
  */
-@NullMarked
-public class SlimeTargetLivingEntityEvent extends SlimePathfindEvent {
-
-    private final LivingEntity target;
-
-    @ApiStatus.Internal
-    public SlimeTargetLivingEntityEvent(final AbstractCubeMob cubeMob, final LivingEntity target) {
-        super(cubeMob);
-        this.target = target;
-    }
+public interface SlimeTargetLivingEntityEvent extends SlimePathfindEvent {
 
     /**
      * Get the targeted entity
      *
      * @return Targeted entity
      */
-    public LivingEntity getTarget() {
-        return this.target;
-    }
+    LivingEntity getTarget();
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/SlimeWanderEvent.java

@@ -1,20 +1,10 @@
 package com.destroystokyo.paper.event.entity;
 
-import org.bukkit.entity.AbstractCubeMob;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
-
 /**
  * Fired when a Slime decides to start wandering.
  * <p>
  * This event does not fire for the entity's actual movement. Only when it
  * is choosing to start moving.
  */
-@NullMarked
-public class SlimeWanderEvent extends SlimePathfindEvent {
-
-    @ApiStatus.Internal
-    public SlimeWanderEvent(final AbstractCubeMob cubeMob) {
-        super(cubeMob);
-    }
+public interface SlimeWanderEvent extends SlimePathfindEvent {
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/ThrownEggHatchEvent.java

@@ -1,54 +1,39 @@
 package com.destroystokyo.paper.event.entity;
 
-import com.google.common.base.Preconditions;
 import org.bukkit.entity.Egg;
 import org.bukkit.entity.EntityType;
-import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
+import org.bukkit.event.entity.EntityEvent;
+import org.checkerframework.checker.index.qual.NonNegative;
 
 /**
  * Called when a thrown egg might hatch.
  * <p>
  * This event fires for all thrown eggs that may hatch, players, dispensers, etc.
  */
-@NullMarked
-public class ThrownEggHatchEvent extends Event {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final Egg egg;
-    private boolean hatching;
-    private byte numHatches;
-    private EntityType hatchType;
-
-    @ApiStatus.Internal
-    public ThrownEggHatchEvent(final Egg egg, final boolean hatching, final byte numHatches, final EntityType hatchingType) {
-        this.egg = egg;
-        this.hatching = hatching;
-        this.numHatches = numHatches;
-        this.hatchType = hatchingType;
-    }
+public interface ThrownEggHatchEvent extends EntityEvent {
 
     /**
      * Gets the egg involved in this event.
      *
      * @return the egg involved in this event
+     * @deprecated use {@link #getEntity()}
      */
-    public Egg getEgg() {
-        return this.egg;
+    @Deprecated(forRemoval = true)
+    default Egg getEgg() {
+        return this.getEntity();
     }
 
+    @Override
+    Egg getEntity();
+
     /**
      * Gets whether the egg is hatching or not. Will be what the server
      * would've done without interaction.
      *
      * @return boolean Whether the egg is going to hatch or not
      */
-    public boolean isHatching() {
-        return this.hatching;
-    }
+    boolean isHatching();
 
     /**
      * Sets whether the egg will hatch or not.
@@ -56,28 +41,7 @@ public class ThrownEggHatchEvent extends Event {
      * @param hatching {@code true} if you want the egg to hatch, {@code false} if you want it
      *                 not to
      */
-    public void setHatching(final boolean hatching) {
-        this.hatching = hatching;
-    }
-
-    /**
-     * Get the type of the mob being hatched ({@link EntityType#CHICKEN} by default)
-     *
-     * @return The type of the mob being hatched by the egg
-     */
-    public EntityType getHatchingType() {
-        return this.hatchType;
-    }
-
-    /**
-     * Change the type of mob being hatched by the egg
-     *
-     * @param hatchType The type of the mob being hatched by the egg
-     */
-    public void setHatchingType(final EntityType hatchType) {
-        Preconditions.checkArgument(hatchType.isSpawnable(), "Can't spawn that entity type from an egg!");
-        this.hatchType = hatchType;
-    }
+    void setHatching(boolean hatching);
 
     /**
      * Get the number of mob hatches from the egg. By default, the number will
@@ -90,9 +54,7 @@ public class ThrownEggHatchEvent extends Event {
      *
      * @return The number of mobs going to be hatched by the egg
      */
-    public byte getNumHatches() {
-        return this.numHatches;
-    }
+    @NonNegative byte getNumHatches();
 
     /**
      * Change the number of mobs coming out of the hatched egg
@@ -102,16 +64,26 @@ public class ThrownEggHatchEvent extends Event {
      *
      * @param numHatches The number of mobs coming out of the egg
      */
-    public void setNumHatches(final byte numHatches) {
-        this.numHatches = numHatches;
-    }
+    void setNumHatches(@NonNegative byte numHatches);
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
+    /**
+     * Get the type of the mob being hatched ({@link EntityType#CHICKEN} by default)
+     *
+     * @return The type of the mob being hatched by the egg
+     */
+    EntityType getHatchingType();
 
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    /**
+     * Change the type of mob being hatched by the egg
+     *
+     * @param hatchType The type of the mob being hatched by the egg
+     */
+    void setHatchingType(EntityType hatchType);
+
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/TurtleGoHomeEvent.java

@@ -4,23 +4,11 @@ import org.bukkit.entity.Turtle;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.entity.EntityEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Fired when a Turtle decides to go home
  */
-@NullMarked
-public class TurtleGoHomeEvent extends EntityEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public TurtleGoHomeEvent(final Turtle turtle) {
-        super(turtle);
-    }
+public interface TurtleGoHomeEvent extends EntityEvent, Cancellable {
 
     /**
      * The turtle going home
@@ -28,26 +16,12 @@ public class TurtleGoHomeEvent extends EntityEvent implements Cancellable {
      * @return The turtle
      */
     @Override
-    public Turtle getEntity() {
-        return (Turtle) super.getEntity();
-    }
+    Turtle getEntity();
 
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/TurtleLayEggEvent.java

@@ -5,28 +5,12 @@ import org.bukkit.entity.Turtle;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.entity.EntityEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
+import org.checkerframework.common.value.qual.IntRange;
 
 /**
  * Fired when a Turtle lays eggs
  */
-@NullMarked
-public class TurtleLayEggEvent extends EntityEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final Location location;
-    private int eggCount;
-
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public TurtleLayEggEvent(final Turtle turtle, final Location location, final int eggCount) {
-        super(turtle);
-        this.location = location;
-        this.eggCount = eggCount;
-    }
+public interface TurtleLayEggEvent extends EntityEvent, Cancellable {
 
     /**
      * The turtle laying the eggs
@@ -34,57 +18,33 @@ public class TurtleLayEggEvent extends EntityEvent implements Cancellable {
      * @return The turtle
      */
     @Override
-    public Turtle getEntity() {
-        return (Turtle) super.getEntity();
-    }
+    Turtle getEntity();
 
     /**
      * Get the location where the eggs are being laid
      *
      * @return Location of eggs
      */
-    public Location getLocation() {
-        return this.location.clone();
-    }
+    Location getLocation();
 
     /**
      * Get the number of eggs being laid
      *
      * @return Number of eggs
      */
-    public int getEggCount() {
-        return this.eggCount;
-    }
+    @IntRange(from = 1, to = 4) int getEggCount();
 
     /**
      * Set the number of eggs being laid
      *
      * @param eggCount Number of eggs
      */
-    public void setEggCount(final int eggCount) {
-        if (eggCount < 1) {
-            this.cancelled = true;
-            return;
+    void setEggCount(@IntRange(from = 0, to = 4) int eggCount);
+
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
         }
-        this.eggCount = Math.min(eggCount, 4);
-    }
-
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/TurtleStartDiggingEvent.java

@@ -5,25 +5,11 @@ import org.bukkit.entity.Turtle;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.entity.EntityEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Fired when a Turtle starts digging to lay eggs
  */
-@NullMarked
-public class TurtleStartDiggingEvent extends EntityEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final Location location;
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public TurtleStartDiggingEvent(final Turtle turtle, final Location location) {
-        super(turtle);
-        this.location = location;
-    }
+public interface TurtleStartDiggingEvent extends EntityEvent, Cancellable {
 
     /**
      * The turtle digging
@@ -31,35 +17,19 @@ public class TurtleStartDiggingEvent extends EntityEvent implements Cancellable
      * @return The turtle
      */
     @Override
-    public Turtle getEntity() {
-        return (Turtle) super.getEntity();
-    }
+    Turtle getEntity();
 
     /**
      * Get the location where the turtle is digging
      *
      * @return Location where digging
      */
-    public Location getLocation() {
-        return this.location.clone();
-    }
+    Location getLocation();
 
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/WitchConsumePotionEvent.java

@@ -5,67 +5,38 @@ import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.entity.EntityEvent;
 import org.bukkit.inventory.ItemStack;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 
 /**
  * Fired when a witch consumes the potion in their hand to buff themselves.
  */
-@NullMarked
-public class WitchConsumePotionEvent extends EntityEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private @Nullable ItemStack potion;
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public WitchConsumePotionEvent(final Witch witch, final @Nullable ItemStack potion) {
-        super(witch);
-        this.potion = potion;
-    }
+public interface WitchConsumePotionEvent extends EntityEvent, Cancellable {
 
     @Override
-    public Witch getEntity() {
-        return (Witch) super.getEntity();
-    }
+    Witch getEntity();
 
     /**
      * @return the potion the witch will consume and have the effects applied.
      */
-    public @Nullable ItemStack getPotion() {
-        return this.potion;
-    }
+    @Nullable ItemStack getPotion();
 
     /**
      * Sets the potion to be consumed and applied to the witch.
      *
      * @param potion The potion
      */
-    public void setPotion(final @Nullable ItemStack potion) {
-        this.potion = potion != null ? potion.clone() : null;
-    }
+    void setPotion(@Nullable ItemStack potion);
 
     /**
      * @return Event was cancelled or potion was {@code null}
      */
     @Override
-    public boolean isCancelled() {
-        return this.cancelled || this.potion == null;
-    }
+    boolean isCancelled();
 
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/WitchReadyPotionEvent.java

@@ -5,61 +5,29 @@ import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.entity.EntityEvent;
 import org.bukkit.inventory.ItemStack;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 
-@NullMarked
-public class WitchReadyPotionEvent extends EntityEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private @Nullable ItemStack potion;
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public WitchReadyPotionEvent(final Witch witch, final @Nullable ItemStack potion) {
-        super(witch);
-        this.potion = potion;
-    }
+public interface WitchReadyPotionEvent extends EntityEvent, Cancellable {
 
     @Override
-    public Witch getEntity() {
-        return (Witch) super.getEntity();
-    }
+    Witch getEntity();
 
     /**
      * @return the potion the witch is readying to use
      */
-    public @Nullable ItemStack getPotion() {
-        return this.potion;
-    }
+    @Nullable ItemStack getPotion();
 
     /**
      * Sets the potion the which is going to hold and use
      *
      * @param potion The potion
      */
-    public void setPotion(final @Nullable ItemStack potion) {
-        this.potion = potion != null ? potion.clone() : null;
-    }
+    void setPotion(@Nullable ItemStack potion);
 
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/WitchThrowPotionEvent.java

@@ -6,76 +6,43 @@ import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.entity.EntityEvent;
 import org.bukkit.inventory.ItemStack;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 
 /**
  * Fired when a witch throws a potion at a player
  */
-@NullMarked
-public class WitchThrowPotionEvent extends EntityEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final LivingEntity target;
-    private @Nullable ItemStack potion;
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public WitchThrowPotionEvent(final Witch witch, final LivingEntity target, final @Nullable ItemStack potion) {
-        super(witch);
-        this.target = target;
-        this.potion = potion;
-    }
+public interface WitchThrowPotionEvent extends EntityEvent, Cancellable {
 
     @Override
-    public Witch getEntity() {
-        return (Witch) super.getEntity();
-    }
+    Witch getEntity();
 
     /**
      * @return The target of the potion
      */
-    public LivingEntity getTarget() {
-        return this.target;
-    }
+    LivingEntity getTarget();
 
     /**
      * @return The potion the witch will throw at a player
      */
-    public @Nullable ItemStack getPotion() {
-        return this.potion;
-    }
+    @Nullable ItemStack getPotion();
 
     /**
      * Sets the potion to be thrown at a player
      *
      * @param potion The potion
      */
-    public void setPotion(final @Nullable ItemStack potion) {
-        this.potion = potion != null ? potion.clone() : null;
-    }
+    void setPotion(@Nullable ItemStack potion);
 
     /**
      * @return Event was cancelled or potion was {@code null}
      */
     @Override
-    public boolean isCancelled() {
-        return this.cancelled || this.potion == null;
-    }
+    boolean isCancelled();
 
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/entity/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package com.destroystokyo.paper.event.entity;
+
+import org.jspecify.annotations.NullMarked;

paper-api/src/main/java/com/destroystokyo/paper/event/inventory/PrepareGrindstoneEvent.java

@@ -2,11 +2,7 @@ package com.destroystokyo.paper.event.inventory;
 
 import org.bukkit.Warning;
 import org.bukkit.inventory.GrindstoneInventory;
-import org.bukkit.inventory.InventoryView;
-import org.bukkit.inventory.ItemStack;
-import org.jetbrains.annotations.ApiStatus;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.NullMarked;
 
 /**
  * Called when an item is put in a slot for grinding in a Grindstone
@@ -15,17 +11,9 @@ import org.jetbrains.annotations.Nullable;
  */
 @Deprecated(since = "1.16.1")
 @Warning
-public class PrepareGrindstoneEvent extends PrepareResultEvent {
+@NullMarked
+public interface PrepareGrindstoneEvent extends PrepareResultEvent {
 
-    @ApiStatus.Internal
-    public PrepareGrindstoneEvent(@NotNull InventoryView inventory, @Nullable ItemStack result) {
-        super(inventory, result);
-    }
-
-    @NotNull
     @Override
-    public GrindstoneInventory getInventory() {
-        return (GrindstoneInventory) super.getInventory();
-    }
-
+    GrindstoneInventory getInventory();
 }

paper-api/src/main/java/com/destroystokyo/paper/event/inventory/PrepareResultEvent.java

@@ -1,42 +1,9 @@
 package com.destroystokyo.paper.event.inventory;
 
 import org.bukkit.event.inventory.PrepareInventoryResultEvent;
-import org.bukkit.inventory.InventoryView;
-import org.bukkit.inventory.ItemStack;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
-import org.jspecify.annotations.Nullable;
 
 /**
  * Called when an item is put in an inventory containing a result slot
  */
-@NullMarked
-public class PrepareResultEvent extends PrepareInventoryResultEvent {
-
-    // HandlerList on PrepareInventoryResultEvent to ensure api compat
-
-    @ApiStatus.Internal
-    public PrepareResultEvent(final InventoryView inventory, final @Nullable ItemStack result) {
-        super(inventory, result);
-    }
-
-    /**
-     * Get result item, may be {@code null}.
-     *
-     * @return result item
-     */
-    @Override
-    public @Nullable ItemStack getResult() {
-        return super.getResult();
-    }
-
-    /**
-     * Set result item, may be {@code null}.
-     *
-     * @param result result item
-     */
-    @Override
-    public void setResult(final @Nullable ItemStack result) {
-        super.setResult(result);
-    }
+public interface PrepareResultEvent extends PrepareInventoryResultEvent {
 }

paper-api/src/main/java/com/destroystokyo/paper/event/player/IllegalPacketEvent.java

@@ -1,67 +1,31 @@
 package com.destroystokyo.paper.event.player;
 
-import org.bukkit.entity.Player;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.Nullable;
 
 /**
- * @deprecated Not used
+ * @deprecated not called anymore
  */
 @Deprecated(since = "1.16.4", forRemoval = true)
-public class IllegalPacketEvent extends PlayerEvent {
+public interface IllegalPacketEvent extends PlayerEvent {
 
-    private static final HandlerList HANDLER_LIST = new HandlerList();
+    boolean isShouldKick();
 
-    @Nullable private final String type;
-    @Nullable private final String exceptionMessage;
-    @Nullable private String kickMessage;
-    private boolean shouldKick = true;
+    void setShouldKick(boolean shouldKick);
 
-    @ApiStatus.Internal
-    public IllegalPacketEvent(@NotNull Player player, @Nullable String type, @Nullable String kickMessage, @NotNull Exception e) {
-        super(player);
-        this.type = type;
-        this.kickMessage = kickMessage;
-        this.exceptionMessage = e.getMessage();
-    }
+    @Nullable String getKickMessage();
 
-    public boolean isShouldKick() {
-        return this.shouldKick;
-    }
+    void setKickMessage(@Nullable String kickMessage);
 
-    public void setShouldKick(boolean shouldKick) {
-        this.shouldKick = shouldKick;
-    }
+    @Nullable String getType();
 
-    @Nullable
-    public String getKickMessage() {
-        return this.kickMessage;
-    }
+    @Nullable String getExceptionMessage();
 
-    public void setKickMessage(@Nullable String kickMessage) {
-        this.kickMessage = kickMessage;
-    }
-
-    @Nullable
-    public String getType() {
-        return this.type;
-    }
-
-    @Nullable
-    public String getExceptionMessage() {
-        return this.exceptionMessage;
-    }
-
-    @NotNull
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    @NotNull
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/player/PlayerAdvancementCriterionGrantEvent.java

@@ -2,79 +2,41 @@ package com.destroystokyo.paper.event.player;
 
 import org.bukkit.advancement.Advancement;
 import org.bukkit.advancement.AdvancementProgress;
-import org.bukkit.entity.Player;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Called after a player is granted a criteria in an advancement.
  * If cancelled the criteria will be revoked.
  */
-@NullMarked
-public class PlayerAdvancementCriterionGrantEvent extends PlayerEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final Advancement advancement;
-    private final String criterion;
-    private final AdvancementProgress advancementProgress;
-
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public PlayerAdvancementCriterionGrantEvent(final Player player, final Advancement advancement, final String criterion) {
-        super(player);
-        this.advancement = advancement;
-        this.criterion = criterion;
-        this.advancementProgress = player.getAdvancementProgress(advancement);
-    }
+public interface PlayerAdvancementCriterionGrantEvent extends PlayerEvent, Cancellable {
 
     /**
      * Get the advancement which has been affected.
      *
      * @return affected advancement
      */
-    public Advancement getAdvancement() {
-        return this.advancement;
-    }
+    Advancement getAdvancement();
 
     /**
      * Get the criterion which has been granted.
      *
      * @return granted criterion
      */
-    public String getCriterion() {
-        return this.criterion;
-    }
+    String getCriterion();
 
     /**
-     * Gets the current AdvancementProgress.
+     * Gets the current {@link AdvancementProgress}.
      *
      * @return advancement progress
      */
-    public AdvancementProgress getAdvancementProgress() {
-        return this.advancementProgress;
-    }
+    AdvancementProgress getAdvancementProgress();
 
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/player/PlayerArmorChangeEvent.java

@@ -2,13 +2,11 @@ package com.destroystokyo.paper.event.player;
 
 import java.util.Set;
 import org.bukkit.Material;
-import org.bukkit.entity.Player;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerEvent;
 import org.bukkit.inventory.EquipmentSlot;
 import org.bukkit.inventory.ItemStack;
 import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 
 import static org.bukkit.Material.*;
@@ -19,23 +17,8 @@ import static org.bukkit.Material.*;
  * Not currently called for environmental factors though it <strong>MAY BE IN THE FUTURE</strong>
  * @apiNote Use {@link io.papermc.paper.event.entity.EntityEquipmentChangedEvent} for all entity equipment changes
  */
-@NullMarked
 @ApiStatus.Obsolete(since = "1.21.4")
-public class PlayerArmorChangeEvent extends PlayerEvent {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final SlotType slotType;
-    private final ItemStack oldItem;
-    private final ItemStack newItem;
-
-    @ApiStatus.Internal
-    public PlayerArmorChangeEvent(final Player player, final SlotType slotType, final ItemStack oldItem, final ItemStack newItem) {
-        super(player);
-        this.slotType = slotType;
-        this.oldItem = oldItem;
-        this.newItem = newItem;
-    }
+public interface PlayerArmorChangeEvent extends PlayerEvent {
 
     /**
      * Gets the type of slot being altered.
@@ -44,56 +27,41 @@ public class PlayerArmorChangeEvent extends PlayerEvent {
      * @deprecated {@link SlotType} does not accurately represent what item types are valid in each slot. Use {@link #getSlot()} instead.
      */
     @Deprecated(since = "1.21.4")
-    public SlotType getSlotType() {
-        return this.slotType;
-    }
+    SlotType getSlotType();
 
     /**
      * Gets the slot being altered.
      *
      * @return slot being altered
      */
-    public EquipmentSlot getSlot() {
-        return switch (this.slotType) {
-            case HEAD -> EquipmentSlot.HEAD;
-            case CHEST -> EquipmentSlot.CHEST;
-            case LEGS -> EquipmentSlot.LEGS;
-            case FEET -> EquipmentSlot.FEET;
-        };
-    }
+    EquipmentSlot getSlot();
 
     /**
      * Gets the existing item that's being replaced
      *
      * @return old item
      */
-    public ItemStack getOldItem() {
-        return this.oldItem;
-    }
+    ItemStack getOldItem();
 
     /**
      * Gets the new item that's replacing the old
      *
      * @return new item
      */
-    public ItemStack getNewItem() {
-        return this.newItem;
-    }
+    ItemStack getNewItem();
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 
     /**
      * @deprecated {@link SlotType} does not accurately represent what item types are valid in each slot.
      */
     @Deprecated(since = "1.21.4")
-    public enum SlotType {
+    enum SlotType {
         HEAD(COPPER_HELMET, NETHERITE_HELMET, DIAMOND_HELMET, GOLDEN_HELMET, IRON_HELMET, CHAINMAIL_HELMET, LEATHER_HELMET, CARVED_PUMPKIN, PLAYER_HEAD, SKELETON_SKULL, ZOMBIE_HEAD, CREEPER_HEAD, WITHER_SKELETON_SKULL, TURTLE_HELMET, DRAGON_HEAD, PIGLIN_HEAD),
         CHEST(COPPER_CHESTPLATE, NETHERITE_CHESTPLATE, DIAMOND_CHESTPLATE, GOLDEN_CHESTPLATE, IRON_CHESTPLATE, CHAINMAIL_CHESTPLATE, LEATHER_CHESTPLATE, ELYTRA),
         LEGS(COPPER_LEGGINGS, NETHERITE_LEGGINGS, DIAMOND_LEGGINGS, GOLDEN_LEGGINGS, IRON_LEGGINGS, CHAINMAIL_LEGGINGS, LEATHER_LEGGINGS),

paper-api/src/main/java/com/destroystokyo/paper/event/player/PlayerAttackEntityCooldownResetEvent.java

@@ -1,12 +1,9 @@
 package com.destroystokyo.paper.event.player;
 
 import org.bukkit.entity.Entity;
-import org.bukkit.entity.Player;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Called when processing a player's attack on an entity when the player's attack strength cooldown is reset.
@@ -17,41 +14,22 @@ import org.jspecify.annotations.NullMarked;
  * Additionally, the cancellation of event is misleading as the client will reset the cooldown manually.
  * So there is no way for the server to control this.
  */
-@NullMarked
 @Deprecated(since = "26.1", forRemoval = true)
-public class PlayerAttackEntityCooldownResetEvent extends PlayerEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final Entity attackedEntity;
-    private final float cooledAttackStrength;
-
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public PlayerAttackEntityCooldownResetEvent(final Player player, final Entity attackedEntity, final float cooledAttackStrength) {
-        super(player);
-        this.attackedEntity = attackedEntity;
-        this.cooledAttackStrength = cooledAttackStrength;
-    }
-
-    /**
-     * Get the value of the players cooldown attack strength when they initiated the attack
-     *
-     * @return returns the original player cooldown value
-     */
-    public float getCooledAttackStrength() {
-        return this.cooledAttackStrength;
-    }
+public interface PlayerAttackEntityCooldownResetEvent extends PlayerEvent, Cancellable {
 
     /**
      * Returns the entity attacked by the player
      *
      * @return the entity attacked by the player
      */
-    public Entity getAttackedEntity() {
-        return this.attackedEntity;
-    }
+    Entity getAttackedEntity();
+
+    /**
+     * Get the value of the players cooldown attack strength when they initiated the attack
+     *
+     * @return returns the original player cooldown value
+     */
+    float getCooledAttackStrength();
 
     /**
      * {@inheritDoc}
@@ -59,9 +37,7 @@ public class PlayerAttackEntityCooldownResetEvent extends PlayerEvent implements
      * If an attack cooldown event is cancelled, the players attack strength will remain at the same value instead of being reset.
      */
     @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
+    boolean isCancelled();
 
     /**
      * {@inheritDoc}
@@ -69,16 +45,12 @@ public class PlayerAttackEntityCooldownResetEvent extends PlayerEvent implements
      * Cancelling this event will prevent the target player from having their cooldown reset from attacking this entity
      */
     @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
+    void setCancelled(boolean cancel);
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/player/PlayerClientOptionsChangeEvent.java

@@ -1,128 +1,57 @@
 package com.destroystokyo.paper.event.player;
 
-import com.destroystokyo.paper.ClientOption;
 import com.destroystokyo.paper.ClientOption.ChatVisibility;
 import com.destroystokyo.paper.ClientOption.ParticleVisibility;
 import com.destroystokyo.paper.SkinParts;
-import java.util.Map;
-import org.bukkit.entity.Player;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerEvent;
 import org.bukkit.inventory.MainHand;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Called when the player changes their client settings
  */
-@NullMarked
-public class PlayerClientOptionsChangeEvent extends PlayerEvent {
+public interface PlayerClientOptionsChangeEvent extends PlayerEvent {
 
-    private static final HandlerList HANDLER_LIST = new HandlerList();
+    String getLocale();
 
-    private final String locale;
-    private final int viewDistance;
-    private final ChatVisibility chatVisibility;
-    private final boolean chatColors;
-    private final SkinParts skinparts;
-    private final MainHand mainHand;
-    private final boolean allowsServerListings;
-    private final boolean textFilteringEnabled;
-    private final ParticleVisibility particleVisibility;
+    boolean hasLocaleChanged();
 
-    @ApiStatus.Internal
-    public PlayerClientOptionsChangeEvent(final Player player, final Map<ClientOption<?>, ?> options) {
-        super(player);
+    int getViewDistance();
 
-        this.locale = (String) options.get(ClientOption.LOCALE);
-        this.viewDistance = (int) options.get(ClientOption.VIEW_DISTANCE);
-        this.chatVisibility = (ChatVisibility) options.get(ClientOption.CHAT_VISIBILITY);
-        this.chatColors = (boolean) options.get(ClientOption.CHAT_COLORS_ENABLED);
-        this.skinparts = (SkinParts) options.get(ClientOption.SKIN_PARTS);
-        this.mainHand = (MainHand) options.get(ClientOption.MAIN_HAND);
-        this.allowsServerListings = (boolean) options.get(ClientOption.ALLOW_SERVER_LISTINGS);
-        this.textFilteringEnabled = (boolean) options.get(ClientOption.TEXT_FILTERING_ENABLED);
-        this.particleVisibility = (ParticleVisibility) options.get(ClientOption.PARTICLE_VISIBILITY);
-    }
+    boolean hasViewDistanceChanged();
 
-    public String getLocale() {
-        return this.locale;
-    }
+    ChatVisibility getChatVisibility();
 
-    public boolean hasLocaleChanged() {
-        return !this.locale.equals(this.player.getClientOption(ClientOption.LOCALE));
-    }
+    boolean hasChatVisibilityChanged();
 
-    public int getViewDistance() {
-        return this.viewDistance;
-    }
+    boolean hasChatColorsEnabled();
 
-    public boolean hasViewDistanceChanged() {
-        return this.viewDistance != this.player.getClientOption(ClientOption.VIEW_DISTANCE);
-    }
+    boolean hasChatColorsEnabledChanged();
 
-    public ChatVisibility getChatVisibility() {
-        return this.chatVisibility;
-    }
+    SkinParts getSkinParts();
 
-    public boolean hasChatVisibilityChanged() {
-        return this.chatVisibility != this.player.getClientOption(ClientOption.CHAT_VISIBILITY);
-    }
+    boolean hasSkinPartsChanged();
 
-    public boolean hasChatColorsEnabled() {
-        return this.chatColors;
-    }
+    MainHand getMainHand();
 
-    public boolean hasChatColorsEnabledChanged() {
-        return this.chatColors != this.player.getClientOption(ClientOption.CHAT_COLORS_ENABLED);
-    }
+    boolean hasMainHandChanged();
 
-    public SkinParts getSkinParts() {
-        return this.skinparts;
-    }
+    boolean hasTextFilteringEnabled();
 
-    public boolean hasSkinPartsChanged() {
-        return this.skinparts.getRaw() != this.player.getClientOption(ClientOption.SKIN_PARTS).getRaw();
-    }
+    boolean hasTextFilteringChanged();
 
-    public MainHand getMainHand() {
-        return this.mainHand;
-    }
+    boolean allowsServerListings();
 
-    public boolean hasMainHandChanged() {
-        return this.mainHand != this.player.getClientOption(ClientOption.MAIN_HAND);
-    }
+    boolean hasAllowServerListingsChanged();
 
-    public boolean hasTextFilteringEnabled() {
-        return this.textFilteringEnabled;
-    }
+    ParticleVisibility getParticleVisibility();
 
-    public boolean hasTextFilteringChanged() {
-        return this.textFilteringEnabled != this.player.getClientOption(ClientOption.TEXT_FILTERING_ENABLED);
-    }
+    boolean hasParticleVisibilityChanged();
 
-    public boolean allowsServerListings() {
-        return this.allowsServerListings;
-    }
-
-    public boolean hasAllowServerListingsChanged() {
-        return this.allowsServerListings != this.player.getClientOption(ClientOption.ALLOW_SERVER_LISTINGS);
-    }
-
-    public ParticleVisibility getParticleVisibility() {
-        return this.particleVisibility;
-    }
-
-    public boolean hasParticleVisibilityChanged() {
-        return this.particleVisibility != this.player.getClientOption(ClientOption.PARTICLE_VISIBILITY);
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/player/PlayerConnectionCloseEvent.java

@@ -1,16 +1,14 @@
 package com.destroystokyo.paper.event.player;
 
+import io.papermc.paper.event.connection.ConnectionEvent;
 import java.net.InetAddress;
 import java.util.UUID;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.AsyncPlayerPreLoginEvent;
 import org.bukkit.event.player.PlayerQuitEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
- * <p>
  * This event is invoked when a player has disconnected. It is guaranteed that,
  * if the server is in online-mode, that the provided uuid and username have been
  * validated.
@@ -34,50 +32,27 @@ import org.jspecify.annotations.NullMarked;
  * The event may be invoked asynchronously or synchronously. Plugins should check
  * {@link Event#isAsynchronous()} and handle accordingly.
  */
-@NullMarked
-public class PlayerConnectionCloseEvent extends Event {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final UUID playerUniqueId;
-    private final String playerName;
-    private final InetAddress ipAddress;
-
-    @ApiStatus.Internal
-    public PlayerConnectionCloseEvent(final UUID playerUniqueId, final String playerName, final InetAddress ipAddress, final boolean async) {
-        super(async);
-        this.playerUniqueId = playerUniqueId;
-        this.playerName = playerName;
-        this.ipAddress = ipAddress;
-    }
+public interface PlayerConnectionCloseEvent extends ConnectionEvent {
 
     /**
-     * Returns the {@code UUID} of the player disconnecting.
+     * Returns the {@link UUID} of the player disconnecting.
      */
-    public UUID getPlayerUniqueId() {
-        return this.playerUniqueId;
-    }
+    UUID getPlayerUniqueId();
 
     /**
      * Returns the name of the player disconnecting.
      */
-    public String getPlayerName() {
-        return this.playerName;
-    }
+    String getPlayerName();
 
     /**
      * Returns the player's IP address.
      */
-    public InetAddress getIpAddress() {
-        return this.ipAddress;
-    }
+    InetAddress getIpAddress();
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/player/PlayerElytraBoostEvent.java

@@ -1,99 +1,56 @@
 package com.destroystokyo.paper.event.player;
 
 import org.bukkit.entity.Firework;
-import org.bukkit.entity.Player;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerEvent;
 import org.bukkit.inventory.EquipmentSlot;
 import org.bukkit.inventory.ItemStack;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Fired when a player boosts elytra flight with a firework
  */
-@NullMarked
-public class PlayerElytraBoostEvent extends PlayerEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final ItemStack itemStack;
-    private final Firework firework;
-    private boolean consume = true;
-    private final EquipmentSlot hand;
-
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public PlayerElytraBoostEvent(final Player player, final ItemStack itemStack, final Firework firework, final EquipmentSlot hand) {
-        super(player);
-        this.itemStack = itemStack;
-        this.firework = firework;
-        this.hand = hand;
-    }
+public interface PlayerElytraBoostEvent extends PlayerEvent, Cancellable {
 
     /**
      * Get the firework itemstack used
      *
      * @return ItemStack of firework
      */
-    public ItemStack getItemStack() {
-        return this.itemStack;
-    }
+    ItemStack getItemStack();
 
     /**
      * Get the firework entity that was spawned
      *
      * @return Firework entity
      */
-    public Firework getFirework() {
-        return this.firework;
-    }
+    Firework getFirework();
 
     /**
      * Get whether to consume the firework or not
      *
      * @return {@code true} to consume
      */
-    public boolean shouldConsume() {
-        return this.consume;
-    }
+    boolean shouldConsume();
 
     /**
      * Set whether to consume the firework or not
      *
      * @param consume {@code true} to consume
      */
-    public void setShouldConsume(final boolean consume) {
-        this.consume = consume;
-    }
+    void setShouldConsume(boolean consume);
 
     /**
      * Gets the hand holding the firework used for boosting this player.
      *
      * @return interaction hand
      */
-    public EquipmentSlot getHand() {
-        return this.hand;
-    }
+    EquipmentSlot getHand();
 
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/player/PlayerHandshakeEvent.java

@@ -1,15 +1,10 @@
 package com.destroystokyo.paper.event.player;
 
-import com.google.common.base.Preconditions;
 import java.util.UUID;
 import net.kyori.adventure.text.Component;
-import net.kyori.adventure.text.format.NamedTextColor;
-import net.kyori.adventure.text.serializer.legacy.LegacyComponentSerializer;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 
 /**
@@ -20,44 +15,14 @@ import org.jspecify.annotations.Nullable;
  *
  * <p>WARNING: TAMPERING WITH THIS EVENT CAN BE DANGEROUS</p>
  */
-@NullMarked
-public class PlayerHandshakeEvent extends Event implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final String originalHandshake;
-    private final String originalSocketAddressHostname;
-    private @Nullable String serverHostname;
-    private @Nullable String socketAddressHostname;
-    private @Nullable UUID uniqueId;
-    private @Nullable String propertiesJson;
-    private boolean failed;
-    private Component failMessage = Component.text("If you wish to use IP forwarding, please enable it in your BungeeCord config as well!", NamedTextColor.YELLOW);
-
-    private boolean cancelled;
-
-    @Deprecated
-    @ApiStatus.Internal
-    public PlayerHandshakeEvent(final String originalHandshake, final boolean cancelled) {
-        this(originalHandshake, "127.0.0.1", cancelled);
-    }
-
-    @ApiStatus.Internal
-    public PlayerHandshakeEvent(final String originalHandshake, final String originalSocketAddressHostname, final boolean cancelled) {
-        super(true);
-        this.originalHandshake = originalHandshake;
-        this.originalSocketAddressHostname = originalSocketAddressHostname;
-        this.cancelled = cancelled;
-    }
+public interface PlayerHandshakeEvent extends Event, Cancellable {
 
     /**
      * Gets the original handshake string.
      *
      * @return the original handshake string
      */
-    public String getOriginalHandshake() {
-        return this.originalHandshake;
-    }
+    String getOriginalHandshake();
 
     /**
      * Gets the original socket address hostname.
@@ -67,9 +32,7 @@ public class PlayerHandshakeEvent extends Event implements Cancellable {
      *
      * @return the original socket address hostname
      */
-    public String getOriginalSocketAddressHostname() {
-        return this.originalSocketAddressHostname;
-    }
+    String getOriginalSocketAddressHostname();
 
     /**
      * Gets the server hostname string.
@@ -78,9 +41,7 @@ public class PlayerHandshakeEvent extends Event implements Cancellable {
      *
      * @return the server hostname string
      */
-    public @Nullable String getServerHostname() {
-        return this.serverHostname;
-    }
+    @Nullable String getServerHostname();
 
     /**
      * Sets the server hostname string.
@@ -89,9 +50,7 @@ public class PlayerHandshakeEvent extends Event implements Cancellable {
      *
      * @param serverHostname the server hostname string
      */
-    public void setServerHostname(final String serverHostname) {
-        this.serverHostname = serverHostname;
-    }
+    void setServerHostname(String serverHostname);
 
     /**
      * Gets the socket address hostname string.
@@ -100,9 +59,7 @@ public class PlayerHandshakeEvent extends Event implements Cancellable {
      *
      * @return the socket address hostname string
      */
-    public @Nullable String getSocketAddressHostname() {
-        return this.socketAddressHostname;
-    }
+    @Nullable String getSocketAddressHostname();
 
     /**
      * Sets the socket address hostname string.
@@ -111,27 +68,21 @@ public class PlayerHandshakeEvent extends Event implements Cancellable {
      *
      * @param socketAddressHostname the socket address hostname string
      */
-    public void setSocketAddressHostname(final String socketAddressHostname) {
-        this.socketAddressHostname = socketAddressHostname;
-    }
+    void setSocketAddressHostname(String socketAddressHostname);
 
     /**
      * Gets the unique id.
      *
      * @return the unique id
      */
-    public @Nullable UUID getUniqueId() {
-        return this.uniqueId;
-    }
+    @Nullable UUID getUniqueId();
 
     /**
      * Sets the unique id.
      *
      * @param uniqueId the unique id
      */
-    public void setUniqueId(final UUID uniqueId) {
-        this.uniqueId = uniqueId;
-    }
+    void setUniqueId(UUID uniqueId);
 
     /**
      * Gets the profile properties.
@@ -140,9 +91,7 @@ public class PlayerHandshakeEvent extends Event implements Cancellable {
      *
      * @return the profile properties, as JSON
      */
-    public @Nullable String getPropertiesJson() {
-        return this.propertiesJson;
-    }
+    @Nullable String getPropertiesJson();
 
     /**
      * Determines if authentication failed.
@@ -152,9 +101,7 @@ public class PlayerHandshakeEvent extends Event implements Cancellable {
      *
      * @return {@code true} if authentication failed, {@code false} otherwise
      */
-    public boolean isFailed() {
-        return this.failed;
-    }
+    boolean isFailed();
 
     /**
      * Sets if authentication failed and the client should be disconnected.
@@ -164,9 +111,7 @@ public class PlayerHandshakeEvent extends Event implements Cancellable {
      *
      * @param failed {@code true} if authentication failed, {@code false} otherwise
      */
-    public void setFailed(final boolean failed) {
-        this.failed = failed;
-    }
+    void setFailed(boolean failed);
 
     /**
      * Sets the profile properties.
@@ -175,27 +120,21 @@ public class PlayerHandshakeEvent extends Event implements Cancellable {
      *
      * @param propertiesJson the profile properties, as JSON
      */
-    public void setPropertiesJson(final String propertiesJson) {
-        this.propertiesJson = propertiesJson;
-    }
+    void setPropertiesJson(String propertiesJson);
 
     /**
      * Gets the message to display to the client when authentication fails.
      *
      * @return the message to display to the client
      */
-    public Component failMessage() {
-        return this.failMessage;
-    }
+    Component failMessage();
 
     /**
      * Sets the message to display to the client when authentication fails.
      *
      * @param failMessage the message to display to the client
      */
-    public void failMessage(final Component failMessage) {
-        this.failMessage = failMessage;
-    }
+    void failMessage(Component failMessage);
 
     /**
      * Gets the message to display to the client when authentication fails.
@@ -204,9 +143,7 @@ public class PlayerHandshakeEvent extends Event implements Cancellable {
      * @deprecated use {@link #failMessage()}
      */
     @Deprecated
-    public String getFailMessage() {
-        return LegacyComponentSerializer.legacySection().serialize(this.failMessage());
-    }
+    String getFailMessage();
 
     /**
      * Sets the message to display to the client when authentication fails.
@@ -215,10 +152,7 @@ public class PlayerHandshakeEvent extends Event implements Cancellable {
      * @deprecated use {@link #failMessage(Component)}
      */
     @Deprecated
-    public void setFailMessage(final String failMessage) {
-        Preconditions.checkArgument(failMessage != null && !failMessage.isEmpty(), "fail message cannot be null or empty");
-        this.failMessage(LegacyComponentSerializer.legacySection().deserialize(failMessage));
-    }
+    void setFailMessage(String failMessage);
 
     /**
      * {@inheritDoc}
@@ -227,9 +161,7 @@ public class PlayerHandshakeEvent extends Event implements Cancellable {
      * be processed.
      */
     @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
+    boolean isCancelled();
 
     /**
      * {@inheritDoc}
@@ -238,16 +170,12 @@ public class PlayerHandshakeEvent extends Event implements Cancellable {
      * be processed.
      */
     @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
+    void setCancelled(boolean cancel);
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/player/PlayerJumpEvent.java

@@ -1,14 +1,10 @@
 package com.destroystokyo.paper.event.player;
 
-import com.google.common.base.Preconditions;
 import org.bukkit.Location;
-import org.bukkit.entity.Player;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerEvent;
 import org.bukkit.event.player.PlayerMoveEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Called when the server detects the player is jumping.
@@ -17,66 +13,21 @@ import org.jspecify.annotations.NullMarked;
  * when checking for jumps via {@link PlayerMoveEvent}, this event is fired whenever
  * the server detects that the player is jumping.
  */
-@NullMarked
-public class PlayerJumpEvent extends PlayerEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final Location to;
-    private Location from;
-
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public PlayerJumpEvent(final Player player, final Location from, final Location to) {
-        super(player);
-        this.from = from;
-        this.to = to;
-    }
-
-    /**
-     * {@inheritDoc}
-     * <p>
-     * If this event is cancelled, the player will be moved or
-     * teleported back to the Location as defined by {@link #getFrom()}. This will not
-     * fire an event
-     */
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    /**
-     * {@inheritDoc}
-     * <p>
-     * If this event is cancelled, the player will be moved or
-     * teleported back to the Location as defined by {@link #getFrom()}. This will not
-     * fire an event
-     */
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
+public interface PlayerJumpEvent extends PlayerEvent, Cancellable {
 
     /**
      * Gets the location this player jumped from
      *
      * @return Location the player jumped from
      */
-    public Location getFrom() {
-        return this.from;
-    }
+    Location getFrom();
 
     /**
      * Sets the location to mark as where the player jumped from
      *
      * @param from New location to mark as the players previous location
      */
-    public void setFrom(final Location from) {
-        Preconditions.checkArgument(from != null, "Cannot use null from location!");
-        Preconditions.checkArgument(from.getWorld() != null, "Cannot use from location with null world!");
-        this.from = from.clone();
-    }
+    void setFrom(Location from);
 
     /**
      * Gets the location this player jumped to
@@ -86,16 +37,32 @@ public class PlayerJumpEvent extends PlayerEvent implements Cancellable {
      *
      * @return Location the player jumped to
      */
-    public Location getTo() {
-        return this.to.clone();
-    }
+    Location getTo();
 
+    /**
+     * {@inheritDoc}
+     * <p>
+     * If this event is cancelled, the player will be moved or
+     * teleported back to the Location as defined by {@link #getFrom()}. This will not
+     * fire an event
+     */
     @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
+    boolean isCancelled();
 
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    /**
+     * {@inheritDoc}
+     * <p>
+     * If this event is cancelled, the player will be moved or
+     * teleported back to the Location as defined by {@link #getFrom()}. This will not
+     * fire an event
+     */
+    @Override
+    void setCancelled(boolean cancel);
+
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/player/PlayerLaunchProjectileEvent.java

@@ -1,14 +1,11 @@
 package com.destroystokyo.paper.event.player;
 
-import org.bukkit.entity.Player;
 import org.bukkit.entity.Projectile;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.entity.EntityShootBowEvent;
 import org.bukkit.event.player.PlayerEvent;
 import org.bukkit.inventory.ItemStack;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Called when a player shoots a projectile.
@@ -17,76 +14,40 @@ import org.jspecify.annotations.NullMarked;
  * of a bow or crossbow. A plugin may listen to {@link EntityShootBowEvent}
  * for these actions instead.
  */
-@NullMarked
-public class PlayerLaunchProjectileEvent extends PlayerEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final Projectile projectile;
-    private final ItemStack itemStack;
-    private boolean consumeItem = true;
-
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public PlayerLaunchProjectileEvent(final Player shooter, final ItemStack itemStack, final Projectile projectile) {
-        super(shooter);
-        this.itemStack = itemStack;
-        this.projectile = projectile;
-    }
+public interface PlayerLaunchProjectileEvent extends PlayerEvent, Cancellable {
 
     /**
      * Gets the projectile which will be launched by this event
      *
      * @return the launched projectile
      */
-    public Projectile getProjectile() {
-        return this.projectile;
-    }
+    Projectile getProjectile();
 
     /**
      * Get the ItemStack used to fire the projectile
      *
      * @return The ItemStack used
      */
-    public ItemStack getItemStack() {
-        return this.itemStack;
-    }
+    ItemStack getItemStack();
 
     /**
      * Get whether to consume the ItemStack or not
      *
      * @return {@code true} to consume
      */
-    public boolean shouldConsume() {
-        return this.consumeItem;
-    }
+    boolean shouldConsume();
 
     /**
      * Set whether to consume the ItemStack or not
      *
      * @param consumeItem {@code true} to consume
      */
-    public void setShouldConsume(final boolean consumeItem) {
-        this.consumeItem = consumeItem;
-    }
+    void setShouldConsume(boolean consumeItem);
 
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/player/PlayerPickupExperienceEvent.java

@@ -24,41 +24,19 @@
 package com.destroystokyo.paper.event.player;
 
 import org.bukkit.entity.ExperienceOrb;
-import org.bukkit.entity.Player;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Fired when a player is attempting to pick up an experience orb
  */
-@NullMarked
-public class PlayerPickupExperienceEvent extends PlayerEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final ExperienceOrb experienceOrb;
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public PlayerPickupExperienceEvent(final Player player, final ExperienceOrb experienceOrb) {
-        super(player);
-        this.experienceOrb = experienceOrb;
-    }
+public interface PlayerPickupExperienceEvent extends PlayerEvent, Cancellable {
 
     /**
-     * @return Returns the Orb that the player is picking up
+     * @return the experience orb that the player is picking up
      */
-    public ExperienceOrb getExperienceOrb() {
-        return this.experienceOrb;
-    }
-
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
+    ExperienceOrb getExperienceOrb();
 
     /**
      * {@inheritDoc}
@@ -66,16 +44,12 @@ public class PlayerPickupExperienceEvent extends PlayerEvent implements Cancella
      * If {@code true}, cancels picking up the experience orb, leaving it in the world
      */
     @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
+    void setCancelled(boolean cancel);
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/player/PlayerPostRespawnEvent.java

@@ -2,31 +2,13 @@ package com.destroystokyo.paper.event.player;
 
 import io.papermc.paper.event.player.AbstractRespawnEvent;
 import org.bukkit.Location;
-import org.bukkit.entity.Player;
 import org.bukkit.event.HandlerList;
-import org.bukkit.event.player.PlayerRespawnEvent;
 import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Fired after a player has respawned
  */
-@NullMarked
-public class PlayerPostRespawnEvent extends AbstractRespawnEvent {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    @ApiStatus.Internal
-    public PlayerPostRespawnEvent(
-        final Player respawnPlayer,
-        final Location respawnLocation,
-        final boolean isBedSpawn,
-        final boolean isAnchorSpawn,
-        final boolean missingRespawnBlock,
-        final PlayerRespawnEvent.RespawnReason respawnReason
-    ) {
-        super(respawnPlayer, respawnLocation, isBedSpawn, isAnchorSpawn, missingRespawnBlock, respawnReason);
-    }
+public interface PlayerPostRespawnEvent extends AbstractRespawnEvent {
 
     /**
      * Returns the location of the respawned player.
@@ -34,17 +16,15 @@ public class PlayerPostRespawnEvent extends AbstractRespawnEvent {
      * @return location of the respawned player
      * @see #getRespawnLocation()
      */
-    @ApiStatus.Obsolete
-    public Location getRespawnedLocation() {
-        return super.getRespawnLocation();
+    @ApiStatus.Obsolete(since = "1.21.5")
+    default Location getRespawnedLocation() {
+        return this.getRespawnLocation();
     }
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/player/PlayerReadyArrowEvent.java

@@ -23,45 +23,25 @@
 
 package com.destroystokyo.paper.event.player;
 
-import org.bukkit.entity.Player;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerEvent;
 import org.bukkit.inventory.ItemStack;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Called when a player is firing a bow and the server is choosing an arrow to use.
  */
-@NullMarked
-public class PlayerReadyArrowEvent extends PlayerEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final ItemStack bow;
-    private final ItemStack arrow;
-
-    private boolean cancelled;
-
-    public PlayerReadyArrowEvent(final Player player, final ItemStack bow, final ItemStack arrow) {
-        super(player);
-        this.bow = bow;
-        this.arrow = arrow;
-    }
+public interface PlayerReadyArrowEvent extends PlayerEvent, Cancellable {
 
     /**
      * @return the player is using to fire the arrow
      */
-    public ItemStack getBow() {
-        return this.bow;
-    }
+    ItemStack getBow();
 
     /**
      * @return the arrow that is attempting to be used
      */
-    public ItemStack getArrow() {
-        return this.arrow;
-    }
+    ItemStack getArrow();
 
     /**
      * {@inheritDoc}
@@ -69,24 +49,18 @@ public class PlayerReadyArrowEvent extends PlayerEvent implements Cancellable {
      * Whether use of this arrow is cancelled. On cancel, the server will try the next arrow available and fire another event.
      */
     @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
+    boolean isCancelled();
 
     /**
      * Cancel use of this arrow. On cancel, the server will try the next arrow available and fire another event.
      */
     @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
+    void setCancelled(boolean cancel);
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/player/PlayerRecipeBookClickEvent.java

@@ -1,50 +1,28 @@
 package com.destroystokyo.paper.event.player;
 
 import org.bukkit.NamespacedKey;
-import org.bukkit.entity.Player;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Called when a player clicks a recipe in the recipe book
  */
-@NullMarked
-public class PlayerRecipeBookClickEvent extends PlayerEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private NamespacedKey recipe;
-    private boolean makeAll;
-
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public PlayerRecipeBookClickEvent(final Player player, final NamespacedKey recipe, final boolean makeAll) {
-        super(player);
-        this.recipe = recipe;
-        this.makeAll = makeAll;
-    }
+public interface PlayerRecipeBookClickEvent extends PlayerEvent, Cancellable {
 
     /**
      * Gets the namespaced key of the recipe that was clicked by the player
      *
      * @return The namespaced key of the recipe
      */
-    public NamespacedKey getRecipe() {
-        return this.recipe;
-    }
+    NamespacedKey getRecipe();
 
     /**
      * Changes what recipe is requested. This sets the requested recipe to the recipe with the given key
      *
      * @param recipe The key of the recipe that should be requested
      */
-    public void setRecipe(final NamespacedKey recipe) {
-        this.recipe = recipe;
-    }
+    void setRecipe(NamespacedKey recipe);
 
     /**
      * Gets a boolean which indicates whether the player requested to make the maximum amount of results. This is
@@ -52,9 +30,7 @@ public class PlayerRecipeBookClickEvent extends PlayerEvent implements Cancellab
      *
      * @return {@code true} if shift is pressed while the recipe is clicked
      */
-    public boolean isMakeAll() {
-        return this.makeAll;
-    }
+    boolean isMakeAll();
 
     /**
      * Sets whether the maximum amount of results should be made. If this is {@code true}, the request is handled as if
@@ -62,26 +38,12 @@ public class PlayerRecipeBookClickEvent extends PlayerEvent implements Cancellab
      *
      * @param makeAll {@code true} if the request should attempt to make the maximum amount of results
      */
-    public void setMakeAll(final boolean makeAll) {
-        this.makeAll = makeAll;
-    }
+    void setMakeAll(boolean makeAll);
 
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/player/PlayerSetSpawnEvent.java

@@ -6,8 +6,6 @@ import org.bukkit.entity.Player;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 
 /**
@@ -15,37 +13,14 @@ import org.jspecify.annotations.Nullable;
  * <br>
  * Cancelling this event will prevent the spawn from being set.
  */
-@NullMarked
-public class PlayerSetSpawnEvent extends PlayerEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final Cause cause;
-    private @Nullable Location location;
-    private boolean forced;
-    private boolean notifyPlayer;
-    private @Nullable Component notification;
-
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public PlayerSetSpawnEvent(final Player player, final Cause cause, final @Nullable Location location, final boolean forced, final boolean notifyPlayer, final @Nullable Component notification) {
-        super(player);
-        this.cause = cause;
-        this.location = location;
-        this.forced = forced;
-        this.notifyPlayer = notifyPlayer;
-        this.notification = notification;
-    }
+public interface PlayerSetSpawnEvent extends PlayerEvent, Cancellable {
 
     /**
      * Gets the cause of this event.
      *
      * @return the cause
      */
-    public Cause getCause() {
-        return this.cause;
-    }
+    Cause getCause();
 
     /**
      * Gets the location that the spawn is set to. The yaw
@@ -55,9 +30,7 @@ public class PlayerSetSpawnEvent extends PlayerEvent implements Cancellable {
      *
      * @return the spawn location, or {@code null} if removing the location
      */
-    public @Nullable Location getLocation() {
-        return this.location;
-    }
+    @Nullable Location getLocation();
 
     /**
      * Sets the location to be set as the spawn location. The yaw
@@ -65,27 +38,21 @@ public class PlayerSetSpawnEvent extends PlayerEvent implements Cancellable {
      *
      * @param location the spawn location, or {@code null} to remove the spawn location
      */
-    public void setLocation(final @Nullable Location location) {
-        this.location = location != null ? location.clone() : null;
-    }
+    void setLocation(@Nullable Location location);
 
     /**
      * Gets if this is a force spawn location
      *
      * @return {@code true} if forced
      */
-    public boolean isForced() {
-        return this.forced;
-    }
+    boolean isForced();
 
     /**
      * Sets if this is a forced spawn location
      *
      * @param forced {@code true} to force
      */
-    public void setForced(final boolean forced) {
-        this.forced = forced;
-    }
+    void setForced(boolean forced);
 
     /**
      * Gets if this action will notify the player their spawn
@@ -93,9 +60,7 @@ public class PlayerSetSpawnEvent extends PlayerEvent implements Cancellable {
      *
      * @return {@code true} to notify
      */
-    public boolean willNotifyPlayer() {
-        return this.notifyPlayer;
-    }
+    boolean willNotifyPlayer();
 
     /**
      * Sets if this action will notify the player that their spawn
@@ -103,9 +68,7 @@ public class PlayerSetSpawnEvent extends PlayerEvent implements Cancellable {
      *
      * @param notifyPlayer {@code true} to notify
      */
-    public void setNotifyPlayer(final boolean notifyPlayer) {
-        this.notifyPlayer = notifyPlayer;
-    }
+    void setNotifyPlayer(boolean notifyPlayer);
 
     /**
      * Gets the notification message that will be sent to the player
@@ -113,39 +76,23 @@ public class PlayerSetSpawnEvent extends PlayerEvent implements Cancellable {
      *
      * @return {@code null} if no notification
      */
-    public @Nullable Component getNotification() {
-        return this.notification;
-    }
+    @Nullable Component getNotification();
 
     /**
      * Sets the notification message that will be sent to the player.
      *
      * @param notification {@code null} to send no message
      */
-    public void setNotification(final @Nullable Component notification) {
-        this.notification = notification;
+    void setNotification(@Nullable Component notification);
+
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
-    }
-
-    public enum Cause {
+    enum Cause {
         /**
          * When a player interacts successfully with a bed.
          */

paper-api/src/main/java/com/destroystokyo/paper/event/player/PlayerStartSpectatingEntityEvent.java

@@ -1,68 +1,34 @@
 package com.destroystokyo.paper.event.player;
 
 import org.bukkit.entity.Entity;
-import org.bukkit.entity.Player;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Triggered when a player starts spectating an entity in spectator mode.
  */
-@NullMarked
-public class PlayerStartSpectatingEntityEvent extends PlayerEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final Entity currentSpectatorTarget;
-    private final Entity newSpectatorTarget;
-
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public PlayerStartSpectatingEntityEvent(final Player player, final Entity currentSpectatorTarget, final Entity newSpectatorTarget) {
-        super(player);
-        this.currentSpectatorTarget = currentSpectatorTarget;
-        this.newSpectatorTarget = newSpectatorTarget;
-    }
+public interface PlayerStartSpectatingEntityEvent extends PlayerEvent, Cancellable {
 
     /**
      * Gets the entity that the player is currently spectating or themselves if they weren't spectating anything
      *
      * @return The entity the player is currently spectating (before they start spectating the new target).
      */
-    public Entity getCurrentSpectatorTarget() {
-        return this.currentSpectatorTarget;
-    }
+    Entity getCurrentSpectatorTarget();
 
     /**
      * Gets the new entity that the player will now be spectating
      *
      * @return The entity the player is now going to be spectating.
      */
-    public Entity getNewSpectatorTarget() {
-        return this.newSpectatorTarget;
-    }
+    Entity getNewSpectatorTarget();
 
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }
 

paper-api/src/main/java/com/destroystokyo/paper/event/player/PlayerStopSpectatingEntityEvent.java

@@ -1,55 +1,26 @@
 package com.destroystokyo.paper.event.player;
 
 import org.bukkit.entity.Entity;
-import org.bukkit.entity.Player;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Triggered when a player stops spectating an entity in spectator mode.
  */
-@NullMarked
-public class PlayerStopSpectatingEntityEvent extends PlayerEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final Entity spectatorTarget;
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public PlayerStopSpectatingEntityEvent(final Player player, final Entity spectatorTarget) {
-        super(player);
-        this.spectatorTarget = spectatorTarget;
-    }
+public interface PlayerStopSpectatingEntityEvent extends PlayerEvent, Cancellable {
 
     /**
      * Gets the entity that the player is spectating
      *
      * @return The entity the player is currently spectating (before they will stop).
      */
-    public Entity getSpectatorTarget() {
-        return this.spectatorTarget;
-    }
+    Entity getSpectatorTarget();
 
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/player/PlayerTeleportEndGatewayEvent.java

@@ -1,32 +1,17 @@
 package com.destroystokyo.paper.event.player;
 
-import org.bukkit.Location;
 import org.bukkit.block.EndGateway;
-import org.bukkit.entity.Player;
 import org.bukkit.event.player.PlayerTeleportEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Fired when a teleport is triggered for an End Gateway
  */
-@NullMarked
-public class PlayerTeleportEndGatewayEvent extends PlayerTeleportEvent {
-
-    private final EndGateway gateway;
-
-    @ApiStatus.Internal
-    public PlayerTeleportEndGatewayEvent(final Player player, final Location from, final Location to, final EndGateway gateway) {
-        super(player, from, to, PlayerTeleportEvent.TeleportCause.END_GATEWAY);
-        this.gateway = gateway;
-    }
+public interface PlayerTeleportEndGatewayEvent extends PlayerTeleportEvent {
 
     /**
      * The gateway triggering the teleport
      *
      * @return EndGateway used
      */
-    public EndGateway getGateway() {
-        return this.gateway;
-    }
+    EndGateway getGateway();
 }

paper-api/src/main/java/com/destroystokyo/paper/event/player/PlayerUseUnknownEntityEvent.java

@@ -1,13 +1,10 @@
 package com.destroystokyo.paper.event.player;
 
-import org.bukkit.entity.Player;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerEvent;
 import org.bukkit.event.player.PlayerInteractAtEntityEvent;
 import org.bukkit.inventory.EquipmentSlot;
 import org.bukkit.util.Vector;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 
 /**
@@ -17,51 +14,28 @@ import org.jspecify.annotations.Nullable;
  * This event may be called multiple times per interaction with different interaction hands
  * and with or without the clicked position.
  */
-@NullMarked
-public class PlayerUseUnknownEntityEvent extends PlayerEvent {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final int entityId;
-    private final boolean attack;
-    private final EquipmentSlot hand;
-    private final @Nullable Vector clickedPosition;
-
-    @ApiStatus.Internal
-    public PlayerUseUnknownEntityEvent(final Player player, final int entityId, final boolean attack, final EquipmentSlot hand, final @Nullable Vector clickedPosition) {
-        super(player);
-        this.entityId = entityId;
-        this.attack = attack;
-        this.hand = hand;
-        this.clickedPosition = clickedPosition;
-    }
+public interface PlayerUseUnknownEntityEvent extends PlayerEvent {
 
     /**
      * Returns the entity id of the unknown entity that was interacted with.
      *
      * @return the entity id of the entity that was interacted with
      */
-    public int getEntityId() {
-        return this.entityId;
-    }
+    int getEntityId();
 
     /**
      * Returns whether the interaction was an attack.
      *
      * @return {@code true} if the player is attacking the entity, {@code false} if the player is interacting with the entity
      */
-    public boolean isAttack() {
-        return this.attack;
-    }
+    boolean isAttack();
 
     /**
      * Returns the hand used to perform this interaction.
      *
      * @return the hand used to interact
      */
-    public EquipmentSlot getHand() {
-        return this.hand;
-    }
+    EquipmentSlot getHand();
 
     /**
      * Returns the position relative to the entity that was clicked, or {@code null} if not available.
@@ -70,16 +44,12 @@ public class PlayerUseUnknownEntityEvent extends PlayerEvent {
      * @return the position relative to the entity that was clicked, or {@code null} if not available
      * @see PlayerInteractAtEntityEvent
      */
-    public @Nullable Vector getClickedRelativePosition() {
-        return this.clickedPosition != null ? this.clickedPosition.clone() : null;
-    }
+    @Nullable Vector getClickedRelativePosition();
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/player/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package com.destroystokyo.paper.event.player;
+
+import org.jspecify.annotations.NullMarked;

paper-api/src/main/java/com/destroystokyo/paper/event/profile/FillProfileEvent.java

@@ -28,31 +28,16 @@ import com.destroystokyo.paper.profile.ProfileProperty;
 import java.util.Set;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Fired once a profiles additional properties (such as textures) has been filled
  */
-@NullMarked
-public class FillProfileEvent extends Event {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final PlayerProfile profile;
-
-    @ApiStatus.Internal
-    public FillProfileEvent(final PlayerProfile profile) {
-        super(!org.bukkit.Bukkit.isPrimaryThread());
-        this.profile = profile;
-    }
+public interface FillProfileEvent extends Event {
 
     /**
      * @return The Profile that had properties filled
      */
-    public PlayerProfile getPlayerProfile() {
-        return this.profile;
-    }
+    PlayerProfile getPlayerProfile();
 
     /**
      * Same as .getPlayerProfile().getProperties()
@@ -60,16 +45,12 @@ public class FillProfileEvent extends Event {
      * @return The new properties on the profile.
      * @see PlayerProfile#getProperties()
      */
-    public Set<ProfileProperty> getProperties() {
-        return this.profile.getProperties();
-    }
+    Set<ProfileProperty> getProperties();
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/profile/LookupProfileEvent.java

@@ -1,13 +1,9 @@
 package com.destroystokyo.paper.event.profile;
 
 import com.destroystokyo.paper.profile.PlayerProfile;
-import org.bukkit.Bukkit;
+import java.util.UUID;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
-import java.util.Objects;
-import java.util.UUID;
 
 /**
  * Allows a plugin to be notified anytime AFTER a Profile has been looked up from the Mojang API
@@ -16,52 +12,33 @@ import java.util.UUID;
  * No guarantees are made about thread execution context for this event. If you need to know, check
  * {@link Event#isAsynchronous()}
  */
-@NullMarked
-public class LookupProfileEvent extends Event {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final PlayerProfile profile;
-
-    @ApiStatus.Internal
-    public LookupProfileEvent(final PlayerProfile profile) {
-        super(!Bukkit.isPrimaryThread());
-        this.profile = profile;
-    }
+public interface LookupProfileEvent extends Event {
 
     /**
      * Gets the name of the profile that was looked up.
      *
      * @return the name of the profile
      */
-    public String getName() {
-        return Objects.requireNonNull(this.profile.getName(), "profile name");
-    }
+    String getName();
 
     /**
      * Gets the UUID of the profile that was looked up.
      *
      * @return the UUID of the profile
      */
-    public UUID getId() {
-        return Objects.requireNonNull(this.profile.getId(), "profile id");
-    }
+    UUID getId();
 
     /**
      * @return The profile that was recently looked up. This profile can be mutated
      * @deprecated This event is only called after UUID lookups, properties set here will be ignored. Use {@link FillProfileEvent} for setting properties.
      */
     @Deprecated(forRemoval = true, since = "1.21.9")
-    public PlayerProfile getPlayerProfile() {
-        return this.profile;
-    }
+    PlayerProfile getPlayerProfile();
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/profile/PreFillProfileEvent.java

@@ -28,33 +28,18 @@ import com.destroystokyo.paper.profile.ProfileProperty;
 import java.util.Collection;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Fired when the server is requesting to fill in properties of an incomplete profile, such as textures.
  * <p>
  * Allows plugins to pre-populate cached properties and avoid a call to the Mojang API
  */
-@NullMarked
-public class PreFillProfileEvent extends Event {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final PlayerProfile profile;
-
-    @ApiStatus.Internal
-    public PreFillProfileEvent(final PlayerProfile profile) {
-        super(!org.bukkit.Bukkit.isPrimaryThread());
-        this.profile = profile;
-    }
+public interface PreFillProfileEvent extends Event {
 
     /**
      * @return The profile that needs its properties filled
      */
-    public PlayerProfile getPlayerProfile() {
-        return this.profile;
-    }
+    PlayerProfile getPlayerProfile();
 
     /**
      * Sets the properties on the profile, avoiding the call to the Mojang API
@@ -63,16 +48,12 @@ public class PreFillProfileEvent extends Event {
      * @param properties The properties to set/append
      * @see PlayerProfile#setProperties(Collection)
      */
-    public void setProperties(final Collection<ProfileProperty> properties) {
-        this.profile.setProperties(properties);
-    }
+    void setProperties(Collection<ProfileProperty> properties);
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/profile/PreLookupProfileEvent.java

@@ -1,14 +1,10 @@
 package com.destroystokyo.paper.event.profile;
 
 import com.destroystokyo.paper.profile.ProfileProperty;
-import java.util.HashSet;
 import java.util.Set;
 import java.util.UUID;
-import org.bukkit.Bukkit;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 
 /**
@@ -21,28 +17,12 @@ import org.jspecify.annotations.Nullable;
  * No guarantees are made about thread execution context for this event. If you need to know, check
  * {@link Event#isAsynchronous()}
  */
-@NullMarked
-public class PreLookupProfileEvent extends Event {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final String name;
-
-    private @Nullable UUID uuid;
-    private Set<ProfileProperty> properties = new HashSet<>();
-
-    @ApiStatus.Internal
-    public PreLookupProfileEvent(final String name) {
-        super(!Bukkit.isPrimaryThread());
-        this.name = name;
-    }
+public interface PreLookupProfileEvent extends Event {
 
     /**
      * @return Name of the profile
      */
-    public String getName() {
-        return this.name;
-    }
+    String getName();
 
     /**
      * If this value is left {@code null} by the completion of the event call, then the server will
@@ -51,9 +31,7 @@ public class PreLookupProfileEvent extends Event {
      *
      * @return The UUID of the profile if it has already been provided by a plugin
      */
-    public @Nullable UUID getUUID() {
-        return this.uuid;
-    }
+    @Nullable UUID getUUID();
 
     /**
      * Sets the UUID for this player name. This will skip the initial API call to find the players UUID.
@@ -62,9 +40,7 @@ public class PreLookupProfileEvent extends Event {
      *
      * @param uuid the UUID to set for the profile or {@code null} to reset
      */
-    public void setUUID(final @Nullable UUID uuid) {
-        this.uuid = uuid;
-    }
+    void setUUID(@Nullable UUID uuid);
 
     /**
      * @return The currently pending pre-populated properties.
@@ -72,9 +48,7 @@ public class PreLookupProfileEvent extends Event {
      * @deprecated This event is only called for UUID lookups, properties set here will be ignored. Use {@link PreFillProfileEvent} for setting properties.
      */
     @Deprecated(forRemoval = true, since = "1.21.9")
-    public Set<ProfileProperty> getProfileProperties() {
-        return this.properties;
-    }
+    Set<ProfileProperty> getProfileProperties();
 
     /**
      * Clears any existing pre-populated properties and uses the supplied properties
@@ -84,10 +58,7 @@ public class PreLookupProfileEvent extends Event {
      * @deprecated This event is only called for UUID lookups, properties set here will be ignored. Use {@link PreFillProfileEvent} for setting properties.
      */
     @Deprecated(forRemoval = true, since = "1.21.9")
-    public void setProfileProperties(final Set<ProfileProperty> properties) {
-        this.properties = new HashSet<>();
-        this.properties.addAll(properties);
-    }
+    void setProfileProperties(Set<ProfileProperty> properties);
 
     /**
      * Adds any properties currently missing to the pre-populated properties set, replacing any that already were set. Use {@link PreFillProfileEvent} for setting properties.
@@ -97,17 +68,12 @@ public class PreLookupProfileEvent extends Event {
      * @deprecated This event is only called for UUID lookups, properties set here will be ignored.
      */
     @Deprecated(forRemoval = true, since = "1.21.9")
-    public void addProfileProperties(final Set<ProfileProperty> properties) {
-        this.properties.addAll(properties);
-    }
+    void addProfileProperties(Set<ProfileProperty> properties);
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
-    }
-
 }

paper-api/src/main/java/com/destroystokyo/paper/event/profile/ProfileWhitelistVerifyEvent.java

@@ -25,12 +25,9 @@ package com.destroystokyo.paper.event.profile;
 
 import com.destroystokyo.paper.profile.PlayerProfile;
 import net.kyori.adventure.text.Component;
-import net.kyori.adventure.text.serializer.legacy.LegacyComponentSerializer;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
-import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.Contract;
-import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 
 /**
@@ -39,102 +36,64 @@ import org.jspecify.annotations.Nullable;
  * Plugins may override/control the servers whitelist with this event,
  * and dynamically change the kick message.
  */
-@NullMarked
-public class ProfileWhitelistVerifyEvent extends Event {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final PlayerProfile profile;
-    private final boolean whitelistEnabled;
-    private final boolean isOp;
-    private boolean whitelisted;
-    private @Nullable Component kickMessage;
-
-    @ApiStatus.Internal
-    public ProfileWhitelistVerifyEvent(final PlayerProfile profile, final boolean whitelistEnabled, final boolean whitelisted, final boolean isOp, final @Nullable Component kickMessage) {
-        this.profile = profile;
-        this.whitelistEnabled = whitelistEnabled;
-        this.whitelisted = whitelisted;
-        this.isOp = isOp;
-        this.kickMessage = kickMessage;
-    }
+public interface ProfileWhitelistVerifyEvent extends Event {
 
     /**
      * @return the currently planned message to send to the user if they are not whitelisted
      * @deprecated use {@link #kickMessage()}
      */
     @Deprecated
-    public @Nullable String getKickMessage() {
-        return this.kickMessage == null ? null : LegacyComponentSerializer.legacySection().serialize(this.kickMessage);
-    }
+    @Nullable String getKickMessage();
 
     /**
      * @param kickMessage The message to send to the player on kick if not whitelisted. May set to {@code null} to use the server configured default
      * @deprecated Use {@link #kickMessage(Component)}
      */
     @Deprecated
-    public void setKickMessage(final @Nullable String kickMessage) {
-        this.kickMessage(kickMessage == null ? null : LegacyComponentSerializer.legacySection().deserialize(kickMessage));
-    }
+    void setKickMessage(@Nullable String kickMessage);
 
     /**
      * @return the currently planned message to send to the user if they are not whitelisted
      */
     @Contract(pure = true)
-    public @Nullable Component kickMessage() {
-        return this.kickMessage;
-    }
+    @Nullable Component kickMessage();
 
     /**
      * @param kickMessage The message to send to the player on kick if not whitelisted. May set to {@code null} to use the server configured default
      */
-    public void kickMessage(final @Nullable Component kickMessage) {
-        this.kickMessage = kickMessage;
-    }
+    void kickMessage(@Nullable Component kickMessage);
 
     /**
      * @return The profile of the player trying to connect
      */
-    public PlayerProfile getPlayerProfile() {
-        return this.profile;
-    }
+    PlayerProfile getPlayerProfile();
 
     /**
      * @return Whether the player is whitelisted to play on this server (whitelist may be off is why it's true)
      */
-    public boolean isWhitelisted() {
-        return this.whitelisted;
-    }
+    boolean isWhitelisted();
 
     /**
      * Changes the players whitelisted state. {@code false} will deny the login
      *
      * @param whitelisted The new whitelisted state
      */
-    public void setWhitelisted(final boolean whitelisted) {
-        this.whitelisted = whitelisted;
-    }
+    void setWhitelisted(boolean whitelisted);
 
     /**
      * @return if the player obtained whitelist status by having op
      */
-    public boolean isOp() {
-        return this.isOp;
-    }
+    boolean isOp();
 
     /**
      * @return if the server even has whitelist on
      */
-    public boolean isWhitelistEnabled() {
-        return this.whitelistEnabled;
-    }
+    boolean isWhitelistEnabled();
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/profile/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package com.destroystokyo.paper.event.profile;
+
+import org.jspecify.annotations.NullMarked;

paper-api/src/main/java/com/destroystokyo/paper/event/server/AsyncTabCompleteEvent.java

@@ -24,10 +24,7 @@
 package com.destroystokyo.paper.event.server;
 
 import com.google.common.base.Preconditions;
-import io.papermc.paper.util.TransformingRandomAccessList;
-import java.util.ArrayList;
 import java.util.List;
-import java.util.Objects;
 import net.kyori.adventure.text.Component;
 import org.bukkit.Location;
 import org.bukkit.command.Command;
@@ -35,8 +32,6 @@ import org.bukkit.command.CommandSender;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 
 /**
@@ -48,52 +43,14 @@ import org.jspecify.annotations.Nullable;
  * <p>
  * Only 1 process will be allowed to provide completions, the Async Event, or the standard process.
  */
-@NullMarked
-public class AsyncTabCompleteEvent extends Event implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final CommandSender sender;
-    private final String buffer;
-    private final boolean isCommand;
-    private final @Nullable Location location;
-    private final List<Completion> completions = new ArrayList<>();
-    private final List<String> stringCompletions = new TransformingRandomAccessList<>(
-        this.completions,
-        Completion::suggestion,
-        Completion::completion
-    );
-    private boolean handled;
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public AsyncTabCompleteEvent(final CommandSender sender, final String buffer, final boolean isCommand, final @Nullable Location loc) {
-        super(true);
-        this.sender = sender;
-        this.buffer = buffer;
-        this.isCommand = isCommand;
-        this.location = loc;
-    }
-
-    @Deprecated
-    @ApiStatus.Internal
-    public AsyncTabCompleteEvent(final CommandSender sender, final List<String> completions, final String buffer, final boolean isCommand, final @Nullable Location loc) {
-        super(true);
-        this.sender = sender;
-        this.completions.addAll(fromStrings(completions));
-        this.buffer = buffer;
-        this.isCommand = isCommand;
-        this.location = loc;
-    }
+public interface AsyncTabCompleteEvent extends Event, Cancellable {
 
     /**
      * Get the sender completing this command.
      *
      * @return the {@link CommandSender} instance
      */
-    public CommandSender getSender() {
-        return this.sender;
-    }
+    CommandSender getSender();
 
     /**
      * The list of completions which will be offered to the sender, in order.
@@ -105,9 +62,7 @@ public class AsyncTabCompleteEvent extends Event implements Cancellable {
      *
      * @return a list of offered completions
      */
-    public List<String> getCompletions() {
-        return this.stringCompletions;
-    }
+    List<String> getCompletions();
 
     /**
      * Set the completions offered, overriding any already set.
@@ -119,14 +74,7 @@ public class AsyncTabCompleteEvent extends Event implements Cancellable {
      *
      * @param completions the new completions
      */
-    public void setCompletions(final List<String> completions) {
-        Preconditions.checkArgument(completions != null, "Completions list cannot be null");
-        if (completions == this.stringCompletions) {
-            return;
-        }
-        this.completions.clear();
-        this.completions.addAll(fromStrings(completions));
-    }
+    void setCompletions(List<String> completions);
 
     /**
      * The list of {@link Completion completions} which will be offered to the sender, in order.
@@ -138,9 +86,7 @@ public class AsyncTabCompleteEvent extends Event implements Cancellable {
      *
      * @return a list of offered completions
      */
-    public List<Completion> completions() {
-        return this.completions;
-    }
+    List<Completion> completions();
 
     /**
      * Set the {@link Completion completions} offered, overriding any already set.
@@ -152,34 +98,24 @@ public class AsyncTabCompleteEvent extends Event implements Cancellable {
      *
      * @param newCompletions the new completions
      */
-    public void completions(final List<Completion> newCompletions) {
-        Preconditions.checkArgument(newCompletions != null, "new completions cannot be null");
-        this.completions.clear();
-        this.completions.addAll(newCompletions);
-    }
+    void completions(List<Completion> newCompletions);
 
     /**
      * Return the entire buffer which formed the basis of this completion.
      *
      * @return command buffer, as entered
      */
-    public String getBuffer() {
-        return this.buffer;
-    }
+    String getBuffer();
 
     /**
      * @return {@code true} if it is a command being tab completed, {@code false} if it is a chat message.
      */
-    public boolean isCommand() {
-        return this.isCommand;
-    }
+    boolean isCommand();
 
     /**
      * @return The position looked at by the sender, or {@code null} if none
      */
-    public @Nullable Location getLocation() {
-        return this.location != null ? this.location.clone() : null;
-    }
+    @Nullable Location getLocation();
 
     /**
      * If {@code true}, the standard process of calling {@link Command#tabComplete(CommandSender, String, String[])}
@@ -187,9 +123,7 @@ public class AsyncTabCompleteEvent extends Event implements Cancellable {
      *
      * @return Is completions considered handled. Always {@code true} if completions is not empty.
      */
-    public boolean isHandled() {
-        return !this.completions.isEmpty() || this.handled;
-    }
+    boolean isHandled();
 
     /**
      * Sets whether to consider the completion request handled.
@@ -198,14 +132,7 @@ public class AsyncTabCompleteEvent extends Event implements Cancellable {
      *
      * @param handled if this completion should be marked as being handled
      */
-    public void setHandled(final boolean handled) {
-        this.handled = handled;
-    }
-
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
+    void setHandled(boolean handled);
 
     /**
      * {@inheritDoc}
@@ -213,31 +140,19 @@ public class AsyncTabCompleteEvent extends Event implements Cancellable {
      * Will provide no completions, and will not fire the synchronous process
      */
     @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
+    void setCancelled(boolean cancel);
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
-    }
-
-    private static List<Completion> fromStrings(final List<String> suggestions) {
-        final List<Completion> list = new ArrayList<>(suggestions.size());
-        for (final String suggestion : suggestions) {
-            list.add(new CompletionImpl(suggestion, null));
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
         }
-        return list;
+        return Holder.HANDLER_LIST;
     }
 
     /**
      * A rich tab completion, consisting of a string suggestion, and a nullable {@link Component} tooltip.
      */
-    public interface Completion {
+    interface Completion {
 
         /**
          * Get the suggestion string for this {@link Completion}.
@@ -260,7 +175,7 @@ public class AsyncTabCompleteEvent extends Event implements Cancellable {
          * @return new completion instance
          */
         static Completion completion(final String suggestion) {
-            return new CompletionImpl(suggestion, null);
+            return completion(suggestion, null);
         }
 
         /**
@@ -273,14 +188,11 @@ public class AsyncTabCompleteEvent extends Event implements Cancellable {
          * @return new completion instance
          */
         static Completion completion(final String suggestion, final @Nullable Component tooltip) {
+            Preconditions.checkArgument(suggestion != null, "suggestion cannot be null");
+            record CompletionImpl(String suggestion, @Nullable Component tooltip) implements Completion {
+            }
+
             return new CompletionImpl(suggestion, tooltip);
         }
     }
-
-    @ApiStatus.Internal
-    record CompletionImpl(String suggestion, @Nullable Component tooltip) implements Completion {
-        CompletionImpl {
-            Objects.requireNonNull(suggestion, "suggestion");
-        }
-    }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/server/GS4QueryEvent.java

@@ -10,9 +10,7 @@ import java.util.List;
 import org.bukkit.Server;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
-import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 /**
  * This event is fired if server is getting queried over GS4 Query protocol.
@@ -21,72 +19,47 @@ import org.jspecify.annotations.NullMarked;
  *
  * @author Mark Vainomaa
  */
-@NullMarked
-public final class GS4QueryEvent extends Event {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final QueryType queryType;
-    private final InetAddress querierAddress;
-    private QueryResponse response;
-
-    @ApiStatus.Internal
-    public GS4QueryEvent(final QueryType queryType, final InetAddress querierAddress, final QueryResponse response) {
-        super(true); // should always be called async
-        this.queryType = queryType;
-        this.querierAddress = querierAddress;
-        this.response = response;
-    }
+public interface GS4QueryEvent extends Event {
 
     /**
      * Get query type
      *
      * @return query type
      */
-    public QueryType getQueryType() {
-        return this.queryType;
-    }
+    QueryType getQueryType();
 
     /**
      * Get querier address
      *
      * @return querier address
      */
-    public InetAddress getQuerierAddress() {
-        return this.querierAddress;
-    }
+    InetAddress getQuerierAddress();
 
     /**
      * Get query response
      *
      * @return query response
      */
-    public QueryResponse getResponse() {
-        return this.response;
-    }
+    QueryResponse getResponse();
 
     /**
      * Set query response
      *
      * @param response query response
      */
-    public void setResponse(final QueryResponse response) {
-        this.response = Preconditions.checkNotNull(response, "response");
-    }
+    void setResponse(QueryResponse response);
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 
     /**
      * The type of query
      */
-    public enum QueryType {
+    enum QueryType {
         /**
          * Basic query asks only a subset of information, such as motd, game type (hardcoded to <pre>MINECRAFT</pre>), map,
          * current players, max players, server port and server motd
@@ -99,7 +72,7 @@ public final class GS4QueryEvent extends Event {
         FULL
     }
 
-    public static final class QueryResponse {
+    final class QueryResponse {
 
         private final String motd;
         private final String gameVersion;
@@ -112,7 +85,18 @@ public final class GS4QueryEvent extends Event {
         private final String serverVersion;
         private final Collection<PluginInformation> plugins;
 
-        private QueryResponse(final String motd, final String gameVersion, final String map, final int currentPlayers, final int maxPlayers, final String hostname, final int port, final Collection<String> players, final String serverVersion, final Collection<PluginInformation> plugins) {
+        private QueryResponse(
+            final String motd,
+            final String gameVersion,
+            final String map,
+            final int currentPlayers,
+            final int maxPlayers,
+            final String hostname,
+            final int port,
+            final Collection<String> players,
+            final String serverVersion,
+            final Collection<PluginInformation> plugins
+        ) {
             this.motd = motd;
             this.gameVersion = gameVersion;
             this.map = map;
@@ -248,11 +232,11 @@ public final class GS4QueryEvent extends Event {
          */
         public static final class Builder {
 
-            private @MonotonicNonNull String motd;
-            private @MonotonicNonNull String gameVersion;
-            private @MonotonicNonNull String map;
-            private @MonotonicNonNull String hostname;
-            private @MonotonicNonNull String serverVersion;
+            private @Nullable String motd;
+            private @Nullable String gameVersion;
+            private @Nullable String map;
+            private @Nullable String hostname;
+            private @Nullable String serverVersion;
 
             private int currentPlayers;
             private int maxPlayers;
@@ -265,17 +249,20 @@ public final class GS4QueryEvent extends Event {
             }
 
             public Builder motd(final String motd) {
-                this.motd = Preconditions.checkNotNull(motd, "motd");
+                Preconditions.checkArgument(motd != null, "motd cannot be null");
+                this.motd = motd;
                 return this;
             }
 
             public Builder gameVersion(final String gameVersion) {
-                this.gameVersion = Preconditions.checkNotNull(gameVersion, "gameVersion");
+                Preconditions.checkArgument(gameVersion != null, "gameVersion cannot be null");
+                this.gameVersion = gameVersion;
                 return this;
             }
 
             public Builder map(final String map) {
-                this.map = Preconditions.checkNotNull(map, "map");
+                Preconditions.checkArgument(map != null, "map cannot be null");
+                this.map = map;
                 return this;
             }
 
@@ -292,7 +279,8 @@ public final class GS4QueryEvent extends Event {
             }
 
             public Builder hostname(final String hostname) {
-                this.hostname = Preconditions.checkNotNull(hostname, "hostname");
+                Preconditions.checkArgument(hostname != null, "hostname cannot be null");
+                this.hostname = hostname;
                 return this;
             }
 
@@ -303,12 +291,14 @@ public final class GS4QueryEvent extends Event {
             }
 
             public Builder players(final Collection<String> players) {
-                this.players.addAll(Preconditions.checkNotNull(players, "players"));
+                Preconditions.checkArgument(players != null, "players cannot be null");
+                this.players.addAll(players);
                 return this;
             }
 
             public Builder players(final String... players) {
-                this.players.addAll(Arrays.asList(Preconditions.checkNotNull(players, "players")));
+                Preconditions.checkArgument(players != null, "players cannot be null");
+                this.players.addAll(Arrays.asList(players));
                 return this;
             }
 
@@ -318,17 +308,20 @@ public final class GS4QueryEvent extends Event {
             }
 
             public Builder serverVersion(final String serverVersion) {
-                this.serverVersion = Preconditions.checkNotNull(serverVersion, "serverVersion");
+                Preconditions.checkArgument(serverVersion != null, "serverVersion cannot be null");
+                this.serverVersion = serverVersion;
                 return this;
             }
 
             public Builder plugins(final Collection<PluginInformation> plugins) {
-                this.plugins.addAll(Preconditions.checkNotNull(plugins, "plugins"));
+                Preconditions.checkArgument(plugins != null, "plugins cannot be null");
+                this.plugins.addAll(plugins);
                 return this;
             }
 
             public Builder plugins(final PluginInformation... plugins) {
-                this.plugins.addAll(Arrays.asList(Preconditions.checkNotNull(plugins, "plugins")));
+                Preconditions.checkArgument(plugins != null, "plugins cannot be null");
+                this.plugins.addAll(Arrays.asList(plugins));
                 return this;
             }
 
@@ -343,16 +336,21 @@ public final class GS4QueryEvent extends Event {
              * @return response
              */
             public QueryResponse build() {
+                Preconditions.checkState(this.motd != null, "motd is required");
+                Preconditions.checkState(this.gameVersion != null, "gameVersion is required");
+                Preconditions.checkState(this.map != null, "map is required");
+                Preconditions.checkState(this.hostname != null, "hostname is required");
+                Preconditions.checkState(this.serverVersion != null, "serverVersion is required");
                 return new QueryResponse(
-                    Preconditions.checkNotNull(this.motd, "motd"),
-                    Preconditions.checkNotNull(this.gameVersion, "gameVersion"),
-                    Preconditions.checkNotNull(this.map, "map"),
+                    this.motd,
+                    this.gameVersion,
+                    this.map,
                     this.currentPlayers,
                     this.maxPlayers,
-                    Preconditions.checkNotNull(this.hostname, "hostname"),
+                    this.hostname,
                     this.port,
                     ImmutableList.copyOf(this.players),
-                    Preconditions.checkNotNull(this.serverVersion, "serverVersion"),
+                    this.serverVersion,
                     ImmutableList.copyOf(this.plugins)
                 );
             }
@@ -361,34 +359,66 @@ public final class GS4QueryEvent extends Event {
         /**
          * Plugin information
          */
-        public static class PluginInformation {
+        public interface PluginInformation {
 
-            private String name;
-            private String version;
+            String name();
 
-            public PluginInformation(final String name, final String version) {
-                this.name = Preconditions.checkNotNull(name, "name");
-                this.version = Preconditions.checkNotNull(version, "version");
+            String version();
+
+            PluginInformation withName(String name);
+
+            PluginInformation withVersion(String version);
+
+            /**
+             * @deprecated use {@link #name()}
+             */
+            @Deprecated(forRemoval = true)
+            default String getName() {
+                return this.name();
             }
 
-            public String getName() {
-                return this.name;
+            /**
+             * @deprecated use {@link #withName(String)}
+             */
+            @Deprecated(forRemoval = true)
+            default void setName(String name) {
+                this.withName(name); // no op
             }
 
-            public void setName(final String name) {
-                this.name = name;
+            /**
+             * @deprecated use {@link #version()}
+             */
+            @Deprecated(forRemoval = true)
+            default String getVersion() {
+                return this.version();
             }
 
-            public void setVersion(final String version) {
-                this.version = version;
+            /**
+             * @deprecated use {@link #withVersion(String)}
+             */
+            @Deprecated(forRemoval = true)
+            default void setVersion(String version) {
+                this.withVersion(version); // no op
             }
 
-            public String getVersion() {
-                return this.version;
-            }
+            static PluginInformation of(final String name, final String version) {
+                record PluginInformationImpl(String name, String version) implements PluginInformation {
+                    PluginInformationImpl {
+                        Preconditions.checkArgument(name != null, "name cannot be null");
+                        Preconditions.checkArgument(version != null, "version cannot be null");
+                    }
 
-            public static PluginInformation of(final String name, final String version) {
-                return new PluginInformation(name, version);
+                    @Override
+                    public PluginInformation withName(final String name) {
+                        return new PluginInformationImpl(name, this.version);
+                    }
+
+                    @Override
+                    public PluginInformation withVersion(final String version) {
+                        return new PluginInformationImpl(this.name, version);
+                    }
+                }
+                return new PluginInformationImpl(name, version);
             }
         }
     }

paper-api/src/main/java/com/destroystokyo/paper/event/server/PaperServerListPingEvent.java

@@ -1,80 +1,28 @@
 package com.destroystokyo.paper.event.server;
 
-import static java.util.Objects.requireNonNull;
-
 import com.destroystokyo.paper.network.StatusClient;
 import com.destroystokyo.paper.profile.PlayerProfile;
-import com.destroystokyo.paper.profile.ProfileProperty;
-import com.google.common.base.Preconditions;
-import io.papermc.paper.util.TransformingRandomAccessList;
-import java.util.Collection;
-import java.util.Map;
-import java.util.Set;
-import java.util.concurrent.CompletableFuture;
-import org.bukkit.Bukkit;
+import java.util.Iterator;
+import java.util.List;
+import java.util.UUID;
 import org.bukkit.entity.Player;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.server.ServerListPingEvent;
-import org.bukkit.profile.PlayerTextures;
 import org.bukkit.util.CachedServerIcon;
-
-import java.util.ArrayList;
-import java.util.Iterator;
-import java.util.List;
-import java.util.NoSuchElementException;
-import java.util.UUID;
-
-import org.jetbrains.annotations.ApiStatus;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.Nullable;
 
 /**
  * Extended version of {@link ServerListPingEvent} that allows full control
  * of the response sent to the client.
  */
-public class PaperServerListPingEvent extends ServerListPingEvent implements Cancellable {
-
-    @NotNull private final StatusClient client;
-
-    private int numPlayers;
-    private boolean hidePlayers;
-    @NotNull private final List<ListedPlayerInfo> listedPlayers = new ArrayList<>();
-    @NotNull private final TransformingRandomAccessList<ListedPlayerInfo, PlayerProfile> playerSample = new TransformingRandomAccessList<>(
-        listedPlayers,
-        info -> new UncheckedPlayerProfile(info.name(), info.id()),
-        profile -> new ListedPlayerInfo(profile.getName(), profile.getId())
-    );
-
-    @NotNull private String version;
-    private int protocolVersion;
-
-    @Nullable private CachedServerIcon favicon;
-
-    private boolean cancelled;
-
-    private boolean originalPlayerCount = true;
-    private Object[] players;
-
-    @ApiStatus.Internal
-    public PaperServerListPingEvent(@NotNull StatusClient client, @NotNull net.kyori.adventure.text.Component motd, int numPlayers, int maxPlayers,
-                                    @NotNull String version, int protocolVersion, @Nullable CachedServerIcon favicon) {
-        super("", client.getAddress().getAddress(), motd, numPlayers, maxPlayers);
-        this.client = client;
-        this.numPlayers = numPlayers;
-        this.version = version;
-        this.protocolVersion = protocolVersion;
-        setServerIcon(favicon);
-    }
+public interface PaperServerListPingEvent extends ServerListPingEvent, Cancellable {
 
     /**
      * Returns the {@link StatusClient} pinging the server.
      *
      * @return The client
      */
-    @NotNull
-    public StatusClient getClient() {
-        return this.client;
-    }
+    StatusClient getClient();
 
     /**
      * {@inheritDoc}
@@ -83,13 +31,7 @@ public class PaperServerListPingEvent extends ServerListPingEvent implements Can
      * {@link #shouldHidePlayers()}.</p>
      */
     @Override
-    public int getNumPlayers() {
-        if (this.hidePlayers) {
-            return -1;
-        }
-
-        return this.numPlayers;
-    }
+    int getNumPlayers();
 
     /**
      * Sets the number of players displayed in the server list.
@@ -99,12 +41,7 @@ public class PaperServerListPingEvent extends ServerListPingEvent implements Can
      *
      * @param numPlayers The number of online players
      */
-    public void setNumPlayers(int numPlayers) {
-        if (this.numPlayers != numPlayers) {
-            this.numPlayers = numPlayers;
-            this.originalPlayerCount = false;
-        }
-    }
+    void setNumPlayers(int numPlayers);
 
     /**
      * {@inheritDoc}
@@ -113,13 +50,7 @@ public class PaperServerListPingEvent extends ServerListPingEvent implements Can
      * {@link #shouldHidePlayers()}.
      */
     @Override
-    public int getMaxPlayers() {
-        if (this.hidePlayers) {
-            return -1;
-        }
-
-        return super.getMaxPlayers();
-    }
+    int getMaxPlayers();
 
     /**
      * Returns whether all player related information is hidden in the server
@@ -131,9 +62,7 @@ public class PaperServerListPingEvent extends ServerListPingEvent implements Can
      *
      * @return {@code true} if the player count is hidden
      */
-    public boolean shouldHidePlayers() {
-        return this.hidePlayers;
-    }
+    boolean shouldHidePlayers();
 
     /**
      * Sets whether all player related information is hidden in the server
@@ -145,9 +74,7 @@ public class PaperServerListPingEvent extends ServerListPingEvent implements Can
      *
      * @param hidePlayers {@code true} if the player count should be hidden
      */
-    public void setHidePlayers(boolean hidePlayers) {
-        this.hidePlayers = hidePlayers;
-    }
+    void setHidePlayers(boolean hidePlayers);
 
     /**
      * Returns a mutable list of {@link ListedPlayerInfo} that will be displayed
@@ -158,10 +85,7 @@ public class PaperServerListPingEvent extends ServerListPingEvent implements Can
      *
      * @return The mutable player sample list
      */
-    @NotNull
-    public List<ListedPlayerInfo> getListedPlayers() {
-        return this.listedPlayers;
-    }
+    List<ListedPlayerInfo> getListedPlayers();
 
     /**
      * Returns a mutable list of {@link PlayerProfile} that will be displayed
@@ -173,30 +97,22 @@ public class PaperServerListPingEvent extends ServerListPingEvent implements Can
      * @return The mutable player sample list
      * @deprecated Use {@link #getListedPlayers()}, as this does not contain real player profiles
      */
-    @NotNull
     @Deprecated(forRemoval = true, since = "1.20.6")
-    public List<PlayerProfile> getPlayerSample() {
-        return this.playerSample;
-    }
+    List<PlayerProfile> getPlayerSample();
 
     /**
      * Returns the version that will be sent as server version on the client.
      *
      * @return The server version
      */
-    @NotNull
-    public String getVersion() {
-        return this.version;
-    }
+    String getVersion();
 
     /**
      * Sets the version that will be sent as server version to the client.
      *
      * @param version The server version
      */
-    public void setVersion(@NotNull String version) {
-        this.version = requireNonNull(version, "version");
-    }
+    void setVersion(String version);
 
     /**
      * Returns the protocol version that will be sent as the protocol version
@@ -205,9 +121,7 @@ public class PaperServerListPingEvent extends ServerListPingEvent implements Can
      * @return The protocol version of the server, or {@code -1} if the server
      * has not finished initialization yet
      */
-    public int getProtocolVersion() {
-        return this.protocolVersion;
-    }
+    int getProtocolVersion();
 
     /**
      * Sets the protocol version that will be sent as the protocol version
@@ -215,19 +129,14 @@ public class PaperServerListPingEvent extends ServerListPingEvent implements Can
      *
      * @param protocolVersion The protocol version of the server
      */
-    public void setProtocolVersion(int protocolVersion) {
-        this.protocolVersion = protocolVersion;
-    }
+    void setProtocolVersion(int protocolVersion);
 
     /**
      * Gets the server icon sent to the client.
      *
      * @return The icon to send to the client, or {@code null} for none
      */
-    @Nullable
-    public CachedServerIcon getServerIcon() {
-        return this.favicon;
-    }
+    @Nullable CachedServerIcon getServerIcon();
 
     /**
      * Sets the server icon sent to the client.
@@ -235,14 +144,7 @@ public class PaperServerListPingEvent extends ServerListPingEvent implements Can
      * @param icon The icon to send to the client, or {@code null} for none
      */
     @Override
-    public void setServerIcon(@Nullable CachedServerIcon icon) {
-        if (icon != null && icon.isEmpty()) {
-            // Represent empty icons as null
-            icon = null;
-        }
-
-        this.favicon = icon;
-    }
+    void setServerIcon(@Nullable CachedServerIcon icon);
 
     /**
      * {@inheritDoc}
@@ -251,9 +153,7 @@ public class PaperServerListPingEvent extends ServerListPingEvent implements Can
      * without sending a response to the client.
      */
     @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
+    boolean isCancelled();
 
     /**
      * {@inheritDoc}
@@ -262,9 +162,7 @@ public class PaperServerListPingEvent extends ServerListPingEvent implements Can
      * without sending a response to the client.
      */
     @Override
-    public void setCancelled(boolean cancel) {
-        this.cancelled = cancel;
-    }
+    void setCancelled(boolean cancel);
 
     /**
      * {@inheritDoc}
@@ -281,77 +179,9 @@ public class PaperServerListPingEvent extends ServerListPingEvent implements Can
      * </ul>
      * @deprecated the Iterable interface will be removed at some point
      */
-    @NotNull
     @Override
     @Deprecated(forRemoval = true, since = "1.20.6")
-    public Iterator<Player> iterator() {
-        if (this.players == null) {
-            this.players = getOnlinePlayers();
-        }
-
-        return new PlayerIterator();
-    }
-
-    protected @NotNull Object @NotNull [] getOnlinePlayers() {
-        return Bukkit.getOnlinePlayers().toArray();
-    }
-
-    @NotNull
-    protected Player getBukkitPlayer(@NotNull Object player) {
-        return (Player) player;
-    }
-
-    @ApiStatus.Internal
-    private final class PlayerIterator implements Iterator<Player> {
-
-        private int next;
-        private int current;
-        @Nullable private Player player;
-
-        @Override
-        public boolean hasNext() {
-            for (; this.next < players.length; this.next++) {
-                if (players[this.next] != null) {
-                    return true;
-                }
-            }
-
-            return false;
-        }
-
-        @NotNull
-        @Override
-        public Player next() {
-            if (!hasNext()) {
-                this.player = null;
-                throw new NoSuchElementException();
-            }
-
-            this.current = this.next++;
-            return this.player = getBukkitPlayer(players[this.current]);
-        }
-
-        @Override
-        public void remove() {
-            if (this.player == null) {
-                throw new IllegalStateException();
-            }
-
-            UUID uniqueId = this.player.getUniqueId();
-            this.player = null;
-
-            // Remove player from iterator
-            players[this.current] = null;
-
-            // Remove player from sample
-            getPlayerSample().removeIf(p -> uniqueId.equals(p.getId()));
-
-            // Decrement player count
-            if (originalPlayerCount) {
-                numPlayers--;
-            }
-        }
-    }
+    Iterator<Player> iterator();
 
     /**
      * Represents a player that will be displayed in the player sample of the server list.
@@ -359,131 +189,6 @@ public class PaperServerListPingEvent extends ServerListPingEvent implements Can
      * @param name name of the listed player
      * @param id   UUID of the listed player
      */
-    public record ListedPlayerInfo(@NotNull String name, @NotNull UUID id) {
-    }
-
-    @ApiStatus.Internal
-    private static final class UncheckedPlayerProfile implements PlayerProfile {
-        private String name;
-        private UUID uuid;
-
-        public UncheckedPlayerProfile(final @NotNull String name, final @NotNull UUID uuid) {
-            Preconditions.checkNotNull(name, "name cannot be null");
-            Preconditions.checkNotNull(uuid, "uuid cannot be null");
-            this.name = name;
-            this.uuid = uuid;
-        }
-
-        @Override
-        public @Nullable UUID getUniqueId() {
-            return uuid;
-        }
-
-        @Override
-        public @Nullable String getName() {
-            return name;
-        }
-
-        @Override
-        public @NotNull String setName(@Nullable final String name) {
-            Preconditions.checkNotNull(name, "name cannot be null");
-            return this.name = name;
-        }
-
-        @Override
-        public @Nullable UUID getId() {
-            return uuid;
-        }
-
-        @Override
-        public @Nullable UUID setId(@Nullable final UUID uuid) {
-            Preconditions.checkNotNull(uuid, "uuid cannot be null");
-            return this.uuid = uuid;
-        }
-
-        @Override
-        public @NotNull PlayerTextures getTextures() {
-            throw new UnsupportedOperationException();
-        }
-
-        @Override
-        public void setTextures(@Nullable final PlayerTextures textures) {
-            throw new UnsupportedOperationException();
-        }
-
-        @Override
-        public @NotNull Set<ProfileProperty> getProperties() {
-            throw new UnsupportedOperationException();
-        }
-
-        @Override
-        public boolean hasProperty(@Nullable final String property) {
-            throw new UnsupportedOperationException();
-        }
-
-        @Override
-        public void setProperty(@NotNull final ProfileProperty property) {
-            throw new UnsupportedOperationException();
-        }
-
-        @Override
-        public void setProperties(@NotNull final Collection<ProfileProperty> properties) {
-            throw new UnsupportedOperationException();
-        }
-
-        @Override
-        public boolean removeProperty(@Nullable final String property) {
-            throw new UnsupportedOperationException();
-        }
-
-        @Override
-        public void clearProperties() {
-            throw new UnsupportedOperationException();
-        }
-
-        @Override
-        public boolean isComplete() {
-            return false;
-        }
-
-        @Override
-        public boolean completeFromCache() {
-            throw new UnsupportedOperationException();
-        }
-
-        @Override
-        public boolean completeFromCache(final boolean onlineMode) {
-            throw new UnsupportedOperationException();
-        }
-
-        @Override
-        public boolean completeFromCache(final boolean lookupUUID, final boolean onlineMode) {
-            throw new UnsupportedOperationException();
-        }
-
-        @Override
-        public boolean complete(final boolean textures) {
-            throw new UnsupportedOperationException();
-        }
-
-        @Override
-        public boolean complete(final boolean textures, final boolean onlineMode) {
-            throw new UnsupportedOperationException();
-        }
-
-        @Override
-        public @NotNull CompletableFuture<PlayerProfile> update() {
-            throw new UnsupportedOperationException();
-        }
-
-        @Override
-        public @NotNull PlayerProfile clone() {
-            throw new UnsupportedOperationException();
-        }
-
-        @Override
-        public @NotNull Map<String, Object> serialize() {
-            throw new UnsupportedOperationException();
-        }
+    record ListedPlayerInfo(String name, UUID id) {
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/server/ServerExceptionEvent.java

@@ -1,43 +1,25 @@
 package com.destroystokyo.paper.event.server;
 
 import com.destroystokyo.paper.exception.ServerException;
-import org.bukkit.Bukkit;
-import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
+import org.bukkit.event.server.ServerEvent;
 
 /**
  * Called whenever an exception is thrown in a recoverable section of the server.
  */
-@NullMarked
-public class ServerExceptionEvent extends Event {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final ServerException exception;
-
-    @ApiStatus.Internal
-    public ServerExceptionEvent(final ServerException exception) {
-        super(!Bukkit.isPrimaryThread());
-        this.exception = exception;
-    }
+public interface ServerExceptionEvent extends ServerEvent {
 
     /**
      * Gets the wrapped exception that was thrown.
      *
      * @return Exception thrown
      */
-    public ServerException getException() {
-        return this.exception;
-    }
+    ServerException getException();
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/server/ServerTickEndEvent.java

@@ -1,42 +1,23 @@
 package com.destroystokyo.paper.event.server;
 
-import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
+import org.bukkit.event.server.ServerEvent;
+import org.checkerframework.checker.index.qual.Positive;
 
 /**
  * Called when the server has finished ticking the main loop
  */
-@NullMarked
-public class ServerTickEndEvent extends Event {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final int tickNumber;
-    private final double tickDuration;
-    private final long timeEnd;
-
-    @ApiStatus.Internal
-    public ServerTickEndEvent(final int tickNumber, final double tickDuration, final long timeRemaining) {
-        this.tickNumber = tickNumber;
-        this.tickDuration = tickDuration;
-        this.timeEnd = System.nanoTime() + timeRemaining;
-    }
+public interface ServerTickEndEvent extends ServerEvent {
 
     /**
      * @return What tick this was since start (first tick = 1)
      */
-    public int getTickNumber() {
-        return this.tickNumber;
-    }
+    @Positive int getTickNumber();
 
     /**
      * @return Time in milliseconds of how long this tick took
      */
-    public double getTickDuration() {
-        return this.tickDuration;
-    }
+    double getTickDuration();
 
     /**
      * Amount of nanoseconds remaining before the next tick should start.
@@ -47,16 +28,12 @@ public class ServerTickEndEvent extends Event {
      *
      * @return Amount of nanoseconds remaining before the next tick should start
      */
-    public long getTimeRemaining() {
-        return this.timeEnd - System.nanoTime();
-    }
+    long getTimeRemaining();
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/server/ServerTickStartEvent.java

@@ -1,35 +1,23 @@
 package com.destroystokyo.paper.event.server;
 
-import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
+import org.bukkit.event.server.ServerEvent;
+import org.checkerframework.checker.index.qual.Positive;
 
-@NullMarked
-public class ServerTickStartEvent extends Event {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final int tickNumber;
-
-    @ApiStatus.Internal
-    public ServerTickStartEvent(final int tickNumber) {
-        this.tickNumber = tickNumber;
-    }
+/**
+ * Called when the server has started ticking the main loop
+ */
+public interface ServerTickStartEvent extends ServerEvent {
 
     /**
      * @return What tick this is going be since start (first tick = 1)
      */
-    public int getTickNumber() {
-        return this.tickNumber;
-    }
+    @Positive int getTickNumber();
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/server/WhitelistToggleEvent.java

@@ -2,41 +2,25 @@ package com.destroystokyo.paper.event.server;
 
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * This event is fired when whitelist is toggled
  *
  * @author Mark Vainomaa
  */
-@NullMarked
-public class WhitelistToggleEvent extends Event {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final boolean enabled;
-
-    @ApiStatus.Internal
-    public WhitelistToggleEvent(final boolean enabled) {
-        this.enabled = enabled;
-    }
+public interface WhitelistToggleEvent extends Event {
 
     /**
      * Gets whether whitelist is going to be enabled or not
      *
      * @return Whether whitelist is going to be enabled or not
      */
-    public boolean isEnabled() {
-        return this.enabled;
-    }
+    boolean isEnabled();
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/event/server/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package com.destroystokyo.paper.event.server;
+
+import org.jspecify.annotations.NullMarked;

paper-api/src/main/java/com/destroystokyo/paper/exception/ServerInternalException.java

@@ -1,9 +1,5 @@
 package com.destroystokyo.paper.exception;
 
-import java.util.logging.Level;
-import org.bukkit.Bukkit;
-import com.destroystokyo.paper.event.server.ServerExceptionEvent;
-
 /**
  * Thrown when the internal server throws a recoverable exception.
  */
@@ -24,13 +20,4 @@ public class ServerInternalException extends ServerException {
     protected ServerInternalException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
         super(message, cause, enableSuppression, writableStackTrace);
     }
-
-    public static void reportInternalException(Throwable cause) {
-        try {
-            Bukkit.getPluginManager().callEvent(new ServerExceptionEvent(new ServerInternalException(cause)));
-            ;
-        } catch (Throwable t) {
-            Bukkit.getLogger().log(Level.WARNING, "Exception posting ServerExceptionEvent", t); // Don't want to rethrow!
-        }
-    }
 }

paper-api/src/main/java/com/destroystokyo/paper/loottable/LootableInventoryReplenishEvent.java

@@ -1,46 +1,19 @@
 package com.destroystokyo.paper.loottable;
 
-import org.bukkit.entity.Player;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerEvent;
-import org.jetbrains.annotations.ApiStatus;
 import org.jspecify.annotations.NullMarked;
 
 @NullMarked
-public class LootableInventoryReplenishEvent extends PlayerEvent implements Cancellable {
+public interface LootableInventoryReplenishEvent extends PlayerEvent, Cancellable {
 
-    private static final HandlerList HANDLER_LIST = new HandlerList();
+    LootableInventory getInventory();
 
-    private final LootableInventory inventory;
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public LootableInventoryReplenishEvent(final Player player, final LootableInventory inventory) {
-        super(player);
-        this.inventory = inventory;
-    }
-
-    public LootableInventory getInventory() {
-        return this.inventory;
-    }
-
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/com/destroystokyo/paper/network/NetworkClient.java

@@ -15,7 +15,7 @@ public interface NetworkClient {
      *
      * @return The client's socket address
      */
-    InetSocketAddress getAddress();
+    InetSocketAddress address();
 
     /**
      * Returns the protocol version of the client.
@@ -24,7 +24,7 @@ public interface NetworkClient {
      * @see <a href="https://minecraft.wiki/w/Minecraft_Wiki:Projects/wiki.vg_merge/Protocol_version_numbers">List of protocol
      *     version numbers</a>
      */
-    int getProtocolVersion();
+    int protocolVersion();
 
     /**
      * Returns the virtual host the client is connected to.
@@ -34,6 +34,6 @@ public interface NetworkClient {
      *
      * @return The client's virtual host, or {@code null} if unknown
      */
-    @Nullable InetSocketAddress getVirtualHost();
+    @Nullable InetSocketAddress virtualHost();
 
 }

paper-api/src/main/java/io/papermc/paper/block/bed/BedRuleResultImpl.java

@@ -3,7 +3,5 @@ package io.papermc.paper.block.bed;
 import org.jetbrains.annotations.ApiStatus;
 
 @ApiStatus.Internal
-record BedRuleResultImpl(
-    boolean success
-) implements BedRuleResult {
+record BedRuleResultImpl(boolean success) implements BedRuleResult {
 }

paper-api/src/main/java/io/papermc/paper/connection/PlayerCommonConnection.java

@@ -1,5 +1,6 @@
 package io.papermc.paper.connection;
 
+import com.destroystokyo.paper.profile.PlayerProfile;
 import java.util.Map;
 
 import com.destroystokyo.paper.ClientOption;
@@ -12,6 +13,13 @@ import org.jspecify.annotations.Nullable;
  */
 public interface PlayerCommonConnection extends WritablePlayerCookieConnection, ReadablePlayerCookieConnection, PluginMessageRecipient {
 
+    /**
+     * Gets the profile for this connection.
+     *
+     * @return profile
+     */
+    PlayerProfile getProfile();
+
     /**
      * Sends data to appear in this connection's report logs.
      * This is useful for debugging server state that may be causing

paper-api/src/main/java/io/papermc/paper/connection/PlayerConfigurationConnection.java

@@ -1,6 +1,5 @@
 package io.papermc.paper.connection;
 
-import com.destroystokyo.paper.profile.PlayerProfile;
 import net.kyori.adventure.audience.Audience;
 
 public interface PlayerConfigurationConnection extends PlayerCommonConnection {
@@ -14,13 +13,6 @@ public interface PlayerConfigurationConnection extends PlayerCommonConnection {
      */
     Audience getAudience();
 
-    /**
-     * Gets the profile for this connection.
-     *
-     * @return profile
-     */
-    PlayerProfile getProfile();
-
     /**
      * Clears the players chat history and their local chat.
      */

paper-api/src/main/java/io/papermc/paper/event/block/BeaconActivatedEvent.java

@@ -1,41 +1,26 @@
 package io.papermc.paper.event.block;
 
 import org.bukkit.block.Beacon;
-import org.bukkit.block.Block;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.block.BlockEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Called when a beacon is activated.
  * Activation occurs when the beacon beam becomes visible.
  */
-@NullMarked
-public class BeaconActivatedEvent extends BlockEvent {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    @ApiStatus.Internal
-    public BeaconActivatedEvent(final Block beacon) {
-        super(beacon);
-    }
+public interface BeaconActivatedEvent extends BlockEvent {
 
     /**
      * Returns the beacon that was activated.
      *
      * @return the beacon that was activated.
      */
-    public Beacon getBeacon() {
-        return (Beacon) this.block.getState();
-    }
+    Beacon getBeacon();
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/io/papermc/paper/event/block/BeaconDeactivatedEvent.java

@@ -1,26 +1,14 @@
 package io.papermc.paper.event.block;
 
-import org.bukkit.Material;
 import org.bukkit.block.Beacon;
-import org.bukkit.block.Block;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.block.BlockEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 
 /**
  * Called when a beacon is deactivated, either because its base block(s) or itself were destroyed.
  */
-@NullMarked
-public class BeaconDeactivatedEvent extends BlockEvent {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    @ApiStatus.Internal
-    public BeaconDeactivatedEvent(final Block beacon) {
-        super(beacon);
-    }
+public interface BeaconDeactivatedEvent extends BlockEvent {
 
     /**
      * Returns the beacon that was deactivated.
@@ -29,16 +17,12 @@ public class BeaconDeactivatedEvent extends BlockEvent {
      *
      * @return The beacon that got deactivated, or {@code null} if it does not exist.
      */
-    public @Nullable Beacon getBeacon() {
-        return this.block.getType() == Material.BEACON ? (Beacon) this.block.getState() : null;
-    }
+    @Nullable Beacon getBeacon();
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/io/papermc/paper/event/block/BellRevealRaiderEvent.java

@@ -1,12 +1,9 @@
 package io.papermc.paper.event.block;
 
-import org.bukkit.block.Block;
 import org.bukkit.entity.Raider;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.block.BlockEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jetbrains.annotations.NotNull;
 
 /**
  * Called when a {@link Raider} is revealed by a bell.
@@ -14,33 +11,14 @@ import org.jetbrains.annotations.NotNull;
  * @deprecated use {@link org.bukkit.event.block.BellResonateEvent}
  */
 @Deprecated(since = "1.19.4")
-public class BellRevealRaiderEvent extends BlockEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final Raider raider;
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public BellRevealRaiderEvent(@NotNull Block bell, @NotNull Raider raider) {
-        super(bell);
-        this.raider = raider;
-    }
+public interface BellRevealRaiderEvent extends BlockEvent, Cancellable {
 
     /**
      * Gets the raider that the bell revealed.
      *
      * @return The raider
      */
-    @NotNull
-    public Raider getEntity() {
-        return this.raider;
-    }
-
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
+    Raider getEntity();
 
     /**
      * {@inheritDoc}
@@ -48,16 +26,12 @@ public class BellRevealRaiderEvent extends BlockEvent implements Cancellable {
      * This does not cancel the particle effects shown on the bell, only the entity.
      */
     @Override
-    public void setCancelled(boolean cancel) {
-        this.cancelled = cancel;
-    }
+    void setCancelled(boolean cancel);
 
-    @Override
-    public @NotNull HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static @NotNull HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/io/papermc/paper/event/block/BellRingEvent.java

@@ -1,22 +1,10 @@
 package io.papermc.paper.event.block;
 
-import org.bukkit.block.Block;
-import org.bukkit.block.BlockFace;
-import org.bukkit.entity.Entity;
-import org.jetbrains.annotations.ApiStatus;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-
 /**
  * Called when a bell is rung.
  *
  * @deprecated use {@link org.bukkit.event.block.BellRingEvent}
  */
 @Deprecated(since = "1.19.4")
-public class BellRingEvent extends org.bukkit.event.block.BellRingEvent {
-
-    @ApiStatus.Internal
-    public BellRingEvent(@NotNull Block block, @NotNull BlockFace direction, @Nullable Entity entity) {
-        super(block, direction, entity);
-    }
+public interface BellRingEvent extends org.bukkit.event.block.BellRingEvent {
 }

paper-api/src/main/java/io/papermc/paper/event/block/BlockBreakBlockEvent.java

@@ -5,53 +5,32 @@ import org.bukkit.block.Block;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.block.BlockExpEvent;
 import org.bukkit.inventory.ItemStack;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Called when a block forces another block to break and drop items.
  * <p>
  * Currently called for piston's and liquid flows.
  */
-@NullMarked
-public class BlockBreakBlockEvent extends BlockExpEvent {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final Block source;
-    private final List<ItemStack> drops;
-
-    @ApiStatus.Internal
-    public BlockBreakBlockEvent(final Block block, final Block source, final List<ItemStack> drops) {
-        super(block, 0);
-        this.source = source;
-        this.drops = drops;
-    }
-
-    /**
-     * Gets a mutable list of drops for this event
-     *
-     * @return the drops
-     */
-    public List<ItemStack> getDrops() {
-        return this.drops;
-    }
+public interface BlockBreakBlockEvent extends BlockExpEvent {
 
     /**
      * Gets the block that cause this (e.g. a piston, or adjacent liquid)
      *
      * @return the source
      */
-    public Block getSource() {
-        return this.source;
-    }
+    Block getSource();
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
+    /**
+     * Gets a mutable list of drops for this event
+     *
+     * @return the drops
+     */
+    List<ItemStack> getDrops();
 
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/io/papermc/paper/event/block/BlockBreakProgressUpdateEvent.java

@@ -1,29 +1,13 @@
 package io.papermc.paper.event.block;
 
-import org.bukkit.block.Block;
-import org.bukkit.entity.Entity;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.block.BlockEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
+import org.bukkit.event.entity.EntityEvent;
 
 /**
  * Called when the progress of a block break is updated.
  */
-@NullMarked
-public class BlockBreakProgressUpdateEvent extends BlockEvent {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final float progress;
-    private final Entity entity;
-
-    @ApiStatus.Internal
-    public BlockBreakProgressUpdateEvent(final Block block, final float progress, final Entity entity) {
-        super(block);
-        this.progress = progress;
-        this.entity = entity;
-    }
+public interface BlockBreakProgressUpdateEvent extends BlockEvent, EntityEvent {
 
     /**
      * The progress of the block break
@@ -33,25 +17,12 @@ public class BlockBreakProgressUpdateEvent extends BlockEvent {
      *
      * @return The progress of the block break
      */
-    public float getProgress() {
-        return this.progress;
-    }
+    float getProgress();
 
-    /**
-     * The entity breaking the block.
-     *
-     * @return The entity breaking the block
-     */
-    public Entity getEntity() {
-        return this.entity;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/io/papermc/paper/event/block/BlockFailedDispenseEvent.java

@@ -1,57 +1,29 @@
 package io.papermc.paper.event.block;
 
-import org.bukkit.block.Block;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.block.BlockEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Called when a block tries to dispense an item, but its inventory is empty.
  */
-@NullMarked
-public class BlockFailedDispenseEvent extends BlockEvent {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private boolean shouldPlayEffect = true;
-
-    @ApiStatus.Internal
-    public BlockFailedDispenseEvent(final Block block) {
-        super(block);
-    }
+public interface BlockFailedDispenseEvent extends BlockEvent {
 
     /**
      * @return if the effect should be played
      */
-    public boolean shouldPlayEffect() {
-        return this.shouldPlayEffect;
-    }
+    boolean shouldPlayEffect();
 
     /**
      * Sets if the effect for empty dispensers should be played
      *
      * @param playEffect if the effect should be played
      */
-    public void shouldPlayEffect(final boolean playEffect) {
-        this.shouldPlayEffect = playEffect;
-    }
+    void shouldPlayEffect(boolean playEffect);
 
-    /**
-     * @return {@link #shouldPlayEffect()}
-     */
-    @Override
-    public boolean callEvent() {
-        super.callEvent();
-        return this.shouldPlayEffect();
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/io/papermc/paper/event/block/BlockLockCheckEvent.java

@@ -1,18 +1,12 @@
 package io.papermc.paper.event.block;
 
-import com.google.common.base.Preconditions;
 import io.papermc.paper.block.LockableTileState;
-import java.util.Objects;
 import net.kyori.adventure.sound.Sound;
 import net.kyori.adventure.text.Component;
-import org.bukkit.block.Block;
-import org.bukkit.block.BlockState;
-import org.bukkit.entity.Player;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.block.BlockEvent;
+import org.bukkit.event.player.PlayerEvent;
 import org.bukkit.inventory.ItemStack;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 
 /**
@@ -20,24 +14,7 @@ import org.jspecify.annotations.Nullable;
  * <br>
  * See {@link #setResult(Result)} to change behavior
  */
-@NullMarked
-public class BlockLockCheckEvent extends BlockEvent {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final Player player;
-    private @Nullable Component lockedMessage;
-    private @Nullable Sound lockedSound;
-    private @Nullable ItemStack itemStack;
-    private Result result = Result.DEFAULT;
-
-    @ApiStatus.Internal
-    public BlockLockCheckEvent(final Block block, final Player player, final Component lockedMessage, final Sound lockedSound) {
-        super(block);
-        this.player = player;
-        this.lockedMessage = lockedMessage;
-        this.lockedSound = lockedSound;
-    }
+public interface BlockLockCheckEvent extends BlockEvent, PlayerEvent {
 
     /**
      * Gets the snapshot {@link LockableTileState} of the block entity
@@ -45,20 +22,7 @@ public class BlockLockCheckEvent extends BlockEvent {
      *
      * @return the snapshot block state.
      */
-    public LockableTileState getBlockState() {
-        final BlockState blockState = this.getBlock().getState();
-        Preconditions.checkState(blockState instanceof LockableTileState, "Block state of lock-checked block is no longer a lockable tile state!");
-        return (LockableTileState) blockState;
-    }
-
-    /**
-     * Get the player involved this lock check.
-     *
-     * @return the player
-     */
-    public Player getPlayer() {
-        return this.player;
-    }
+    LockableTileState getBlockState();
 
     /**
      * Gets the itemstack that will be used as the key itemstack. Initially
@@ -69,9 +33,7 @@ public class BlockLockCheckEvent extends BlockEvent {
      * @return the item being used as the key item
      * @see #isUsingCustomKeyItemStack()
      */
-    public ItemStack getKeyItem() {
-        return Objects.requireNonNullElseGet(this.itemStack, this.player.getInventory()::getItemInMainHand);
-    }
+    ItemStack getKeyItem();
 
     /**
      * Sets the itemstack that will be used as the key item.
@@ -79,26 +41,19 @@ public class BlockLockCheckEvent extends BlockEvent {
      * @param stack the stack to use as a key
      * @see #resetKeyItem() to clear a custom key item
      */
-    public void setKeyItem(final ItemStack stack) {
-        Preconditions.checkArgument(stack != null, "stack cannot be null");
-        this.itemStack = stack;
-    }
+    void setKeyItem(ItemStack stack);
 
     /**
      * Reset the key stack to the default (the player's main hand).
      */
-    public void resetKeyItem() {
-        this.itemStack = null;
-    }
+    void resetKeyItem();
 
     /**
      * Checks if a custom key stack has been set.
      *
      * @return {@code true} if a custom key itemstack has been set
      */
-    public boolean isUsingCustomKeyItemStack() {
-        return this.itemStack != null;
-    }
+    boolean isUsingCustomKeyItemStack();
 
     /**
      * Gets the result of this event.
@@ -106,9 +61,7 @@ public class BlockLockCheckEvent extends BlockEvent {
      * @return the result
      * @see #setResult(Result)
      */
-    public Result getResult() {
-        return this.result;
-    }
+    Result getResult();
 
     /**
      * Gets the result of this event. {@link Result#DEFAULT} is the default
@@ -119,9 +72,7 @@ public class BlockLockCheckEvent extends BlockEvent {
      *
      * @param result the result of this event
      */
-    public void setResult(final Result result) {
-        this.result = result;
-    }
+    void setResult(Result result);
 
     /**
      * Shorthand method to set the {@link #getResult()} to {@link Result#DENY},
@@ -130,11 +81,7 @@ public class BlockLockCheckEvent extends BlockEvent {
      * @param lockedMessage the message to show if locked (or {@code null} for none)
      * @param lockedSound   the sound to play if locked (or {@code null} for none)
      */
-    public void denyWithMessageAndSound(final @Nullable Component lockedMessage, final @Nullable Sound lockedSound) {
-        this.result = Result.DENY;
-        this.lockedMessage = lockedMessage;
-        this.lockedSound = lockedSound;
-    }
+    void denyWithMessageAndSound(@Nullable Component lockedMessage, @Nullable Sound lockedSound);
 
     /**
      * Gets the locked message that will be sent if the
@@ -142,9 +89,7 @@ public class BlockLockCheckEvent extends BlockEvent {
      *
      * @return the locked message (or {@code null} if none)
      */
-    public @Nullable Component getLockedMessage() {
-        return this.lockedMessage;
-    }
+    @Nullable Component getLockedMessage();
 
     /**
      * Sets the locked message that will be sent if the
@@ -152,9 +97,7 @@ public class BlockLockCheckEvent extends BlockEvent {
      *
      * @param lockedMessage the locked message (or {@code null} for none)
      */
-    public void setLockedMessage(final @Nullable Component lockedMessage) {
-        this.lockedMessage = lockedMessage;
-    }
+    void setLockedMessage(@Nullable Component lockedMessage);
 
     /**
      * Gets the locked sound that will play if the
@@ -162,9 +105,7 @@ public class BlockLockCheckEvent extends BlockEvent {
      *
      * @return the locked sound (or {@code null} if none)
      */
-    public @Nullable Sound getLockedSound() {
-        return this.lockedSound;
-    }
+    @Nullable Sound getLockedSound();
 
     /**
      * Sets the locked sound that will play if the
@@ -172,16 +113,12 @@ public class BlockLockCheckEvent extends BlockEvent {
      *
      * @param lockedSound the locked sound (or {@code null} for none)
      */
-    public void setLockedSound(final @Nullable Sound lockedSound) {
-        this.lockedSound = lockedSound;
-    }
+    void setLockedSound(@Nullable Sound lockedSound);
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/io/papermc/paper/event/block/BlockPreDispenseEvent.java

@@ -1,64 +1,30 @@
 package io.papermc.paper.event.block;
 
-import org.bukkit.block.Block;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.block.BlockEvent;
 import org.bukkit.inventory.ItemStack;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
-@NullMarked
-public class BlockPreDispenseEvent extends BlockEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final ItemStack itemStack;
-    private final int slot;
-
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public BlockPreDispenseEvent(final Block block, final ItemStack itemStack, final int slot) {
-        super(block);
-        this.itemStack = itemStack;
-        this.slot = slot;
-    }
+public interface BlockPreDispenseEvent extends BlockEvent, Cancellable {
 
     /**
      * Gets the {@link ItemStack} to be dispensed.
      *
      * @return The item to be dispensed
      */
-    public ItemStack getItemStack() {
-        return this.itemStack;
-    }
+    ItemStack getItemStack();
 
     /**
      * Gets the inventory slot of the dispenser to dispense from.
      *
      * @return The inventory slot
      */
-    public int getSlot() {
-        return this.slot;
-    }
+    int getSlot();
 
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/io/papermc/paper/event/block/CompostItemEvent.java

@@ -1,66 +1,41 @@
 package io.papermc.paper.event.block;
 
-import org.bukkit.block.Block;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.block.BlockEvent;
 import org.bukkit.event.inventory.InventoryMoveItemEvent;
 import org.bukkit.inventory.ItemStack;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Called when an item is about to be composted by a hopper.
  * To prevent hoppers from moving items into composters, cancel the {@link InventoryMoveItemEvent}.
  */
-@NullMarked
-public class CompostItemEvent extends BlockEvent {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final ItemStack item;
-    private boolean willRaiseLevel;
-
-    @ApiStatus.Internal
-    public CompostItemEvent(final Block composter, final ItemStack item, final boolean willRaiseLevel) {
-        super(composter);
-        this.item = item;
-        this.willRaiseLevel = willRaiseLevel;
-    }
+public interface CompostItemEvent extends BlockEvent {
 
     /**
      * Gets the item that was used on the composter.
      *
      * @return the item
      */
-    public ItemStack getItem() {
-        return this.item;
-    }
+    ItemStack getItem();
 
     /**
      * Gets whether the composter will rise a level.
      *
      * @return {@code true} if successful
      */
-    public boolean willRaiseLevel() {
-        return this.willRaiseLevel;
-    }
+    boolean willRaiseLevel();
 
     /**
      * Sets whether the composter will rise a level.
      *
      * @param willRaiseLevel {@code true} if the composter should rise a level
      */
-    public void setWillRaiseLevel(final boolean willRaiseLevel) {
-        this.willRaiseLevel = willRaiseLevel;
-    }
+    void setWillRaiseLevel(boolean willRaiseLevel);
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
-    }
-
 }

paper-api/src/main/java/io/papermc/paper/event/block/DragonEggFormEvent.java

@@ -1,14 +1,10 @@
 package io.papermc.paper.event.block;
 
 import org.bukkit.Material;
-import org.bukkit.block.Block;
-import org.bukkit.block.BlockState;
 import org.bukkit.boss.DragonBattle;
 import org.bukkit.entity.EnderDragon;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.block.BlockFormEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Called when the {@link EnderDragon} is defeated (killed) in a {@link DragonBattle},
@@ -18,18 +14,7 @@ import org.jspecify.annotations.NullMarked;
  * <b>This event might be cancelled by default depending on
  * e.g. {@link DragonBattle#hasBeenPreviouslyKilled()} and server configuration.</b>
  */
-@NullMarked
-public class DragonEggFormEvent extends BlockFormEvent {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final DragonBattle dragonBattle;
-
-    @ApiStatus.Internal
-    public DragonEggFormEvent(final Block block, final BlockState newState, final DragonBattle dragonBattle) {
-        super(block, newState);
-        this.dragonBattle = dragonBattle;
-    }
+public interface DragonEggFormEvent extends BlockFormEvent {
 
     /**
      * Gets the {@link DragonBattle} associated with this event.
@@ -38,16 +23,12 @@ public class DragonEggFormEvent extends BlockFormEvent {
      *
      * @return the dragon battle
      */
-    public DragonBattle getDragonBattle() {
-        return this.dragonBattle;
-    }
+    DragonBattle getDragonBattle();
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/io/papermc/paper/event/block/PlayerShearBlockEvent.java

@@ -1,15 +1,12 @@
 package io.papermc.paper.event.block;
 
 import java.util.List;
-import org.bukkit.block.Block;
-import org.bukkit.entity.Player;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
+import org.bukkit.event.block.BlockEvent;
 import org.bukkit.event.player.PlayerEvent;
 import org.bukkit.inventory.EquipmentSlot;
 import org.bukkit.inventory.ItemStack;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 
 /**
  * Called when a player uses shears on a block.
@@ -19,62 +16,28 @@ import org.jspecify.annotations.NullMarked;
  * <p>
  * Examples include shearing a pumpkin to turn it into a carved pumpkin or shearing a beehive to get honeycomb.
  */
-@NullMarked
-public class PlayerShearBlockEvent extends PlayerEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final Block block;
-    private final ItemStack item;
-    private final EquipmentSlot hand;
-    private final List<ItemStack> drops;
-
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public PlayerShearBlockEvent(final Player player, final Block block, final ItemStack item, final EquipmentSlot hand, final List<ItemStack> drops) {
-        super(player);
-        this.block = block;
-        this.item = item;
-        this.hand = hand;
-        this.drops = drops;
-    }
-
-    /**
-     * Gets the block being sheared in this event.
-     *
-     * @return The {@link Block} which block is being sheared in this event.
-     */
-    public Block getBlock() {
-        return this.block;
-    }
+public interface PlayerShearBlockEvent extends PlayerEvent, BlockEvent, Cancellable {
 
     /**
      * Gets the item used to shear the block.
      *
      * @return The {@link ItemStack} of the shears.
      */
-    public ItemStack getItem() {
-        return this.item;
-    }
+    ItemStack getItem();
 
     /**
      * Gets the hand used to shear the block.
      *
      * @return Either {@link EquipmentSlot#HAND} OR {@link EquipmentSlot#OFF_HAND}.
      */
-    public EquipmentSlot getHand() {
-        return this.hand;
-    }
+    EquipmentSlot getHand();
 
     /**
      * Gets the resulting drops of this event.
      *
      * @return A mutable {@link List list} of {@link ItemStack items} that will be dropped as result of this event.
      */
-    public List<ItemStack> getDrops() {
-        return this.drops;
-    }
+    List<ItemStack> getDrops();
 
     /**
      * Gets whether the shearing of the block should be cancelled or not.
@@ -82,9 +45,7 @@ public class PlayerShearBlockEvent extends PlayerEvent implements Cancellable {
      * @return Whether the shearing of the block should be cancelled or not.
      */
     @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
+    boolean isCancelled();
 
     /**
      * Sets whether the shearing of the block should be cancelled or not.
@@ -92,16 +53,12 @@ public class PlayerShearBlockEvent extends PlayerEvent implements Cancellable {
      * @param cancel whether the shearing of the block should be cancelled or not.
      */
     @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
+    void setCancelled(boolean cancel);
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/io/papermc/paper/event/block/TargetHitEvent.java

@@ -1,14 +1,8 @@
 package io.papermc.paper.event.block;
 
-import com.google.common.base.Preconditions;
-import org.bukkit.block.Block;
-import org.bukkit.block.BlockFace;
-import org.bukkit.entity.Projectile;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.entity.ProjectileHitEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jetbrains.annotations.Range;
-import org.jspecify.annotations.NullMarked;
+import org.checkerframework.common.value.qual.IntRange;
 
 /**
  * Called when a Target Block is hit by a projectile.
@@ -17,44 +11,26 @@ import org.jspecify.annotations.NullMarked;
  * and in the case that the shooter is a player, will stop them from receiving
  * advancement criteria.
  */
-@NullMarked
-public class TargetHitEvent extends ProjectileHitEvent {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private int signalStrength;
-
-    @ApiStatus.Internal
-    public TargetHitEvent(final Projectile projectile, final Block block, final BlockFace blockFace, final int signalStrength) {
-        super(projectile, null, block, blockFace);
-        this.signalStrength = signalStrength;
-    }
+public interface TargetHitEvent extends ProjectileHitEvent {
 
     /**
      * Gets the strength of the redstone signal to be emitted by the Target block
      *
      * @return the strength of the redstone signal to be emitted
      */
-    public @Range(from = 0, to = 15) int getSignalStrength() {
-        return this.signalStrength;
-    }
+    @IntRange(from = 0, to = 15) int getSignalStrength();
 
     /**
      * Sets the strength of the redstone signal to be emitted by the Target block
      *
      * @param signalStrength the strength of the redstone signal to be emitted
      */
-    public void setSignalStrength(final @Range(from = 0, to = 15) int signalStrength) {
-        Preconditions.checkArgument(signalStrength >= 0 && signalStrength <= 15, "Signal strength out of range (%s), must be in range [0,15]", signalStrength);
-        this.signalStrength = signalStrength;
-    }
+    void setSignalStrength(@IntRange(from = 0, to = 15) int signalStrength);
 
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/io/papermc/paper/event/block/VaultChangeStateEvent.java

@@ -1,80 +1,42 @@
 package io.papermc.paper.event.block;
 
-import org.bukkit.block.Block;
 import org.bukkit.block.data.type.Vault;
 import org.bukkit.entity.Player;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.block.BlockEvent;
-import org.jetbrains.annotations.ApiStatus;
-import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 
 /**
  * Called when a vault block changes state.
  */
-@NullMarked
-public class VaultChangeStateEvent extends BlockEvent implements Cancellable {
-
-    private static final HandlerList HANDLER_LIST = new HandlerList();
-
-    private final @Nullable Player player;
-    private final Vault.State currentState;
-    private final Vault.State newState;
-
-    private boolean cancelled;
-
-    @ApiStatus.Internal
-    public VaultChangeStateEvent(final Block vaultBlock, final @Nullable Player player, final Vault.State currentState, final Vault.State newState) {
-        super(vaultBlock);
-        this.player = player;
-        this.currentState = currentState;
-        this.newState = newState;
-    }
+public interface VaultChangeStateEvent extends BlockEvent, Cancellable {
 
     /**
      * Gets the player associated with this state change, if applicable.
      *
      * @return The associated player, or {@code null} if not known.
      */
-    public @Nullable Player getPlayer() {
-        return this.player;
-    }
+    @Nullable Player getPlayer();
 
     /**
      * Gets the state the vault is currently in.
      *
      * @return The current vault state.
      */
-    public Vault.State getCurrentState() {
-        return this.currentState;
-    }
+    Vault.State getCurrentState();
 
     /**
      * Gets the state the vault is attempting to transition to.
      *
      * @return The new vault state.
      */
-    public Vault.State getNewState() {
-        return this.newState;
-    }
+    Vault.State getNewState();
 
-    @Override
-    public boolean isCancelled() {
-        return this.cancelled;
-    }
-
-    @Override
-    public void setCancelled(final boolean cancel) {
-        this.cancelled = cancel;
-    }
-
-    @Override
-    public HandlerList getHandlers() {
-        return HANDLER_LIST;
-    }
-
-    public static HandlerList getHandlerList() {
-        return HANDLER_LIST;
+    static HandlerList getHandlerList() {
+        final class Holder {
+            private static final HandlerList HANDLER_LIST = new HandlerList();
+        }
+        return Holder.HANDLER_LIST;
     }
 }

paper-api/src/main/java/io/papermc/paper/event/block/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.papermc.paper.event.block;
+
+import org.jspecify.annotations.NullMarked;

paper-api/src/main/java/io/papermc/paper/event/connection/ConnectionEvent.java

@@ -0,0 +1,15 @@
+package io.papermc.paper.event.connection;
+
+import io.papermc.paper.connection.PlayerConnection;
+import org.bukkit.event.Event;
+
+/**
+ * Represents a connection related event
+ */
+public interface ConnectionEvent extends Event {
+
+    /**
+     * {@return the player connection involved in this event}
+     */
+    PlayerConnection getConnection();
+}