Use npc indices to iterate local npcs

runelite-api/src/main/java/net/runelite/api/Client.java

@@ -25,6 +25,7 @@
 package net.runelite.api;
 
 import java.awt.Canvas;
+import java.util.List;
 
 import net.runelite.api.widgets.Widget;
 import net.runelite.api.widgets.WidgetInfo;
@@ -35,9 +36,7 @@ public interface Client
 
 	Player[] getCachedPlayers();
 
-	NPC getNpc(int idx);
-
-	NPC[] getCachedNPCs();
+	List<NPC> getNpcs();
 
 	int getBoostedSkillLevel(Skill skill);
 

runelite-api/src/main/java/net/runelite/api/queries/NPCQuery.java

@@ -27,16 +27,13 @@ package net.runelite.api.queries;
 import net.runelite.api.Client;
 import net.runelite.api.NPC;
 
-import java.util.Arrays;
-import java.util.Objects;
 
 public class NPCQuery extends ActorQuery<NPC, NPCQuery>
 {
 	@Override
 	public NPC[] result(Client client)
 	{
-		return Arrays.stream(client.getCachedNPCs())
-				.filter(Objects::nonNull)
+		return client.getNpcs().stream()
 				.filter(predicate)
 				.toArray(NPC[]::new);
 	}