--- a/net/minecraft/world/item/trading/Merchant.java
+++ b/net/minecraft/world/item/trading/Merchant.java
@@ -19,6 +_,8 @@
 
     void overrideOffers(MerchantOffers offers);
 
+    default void processTrade(MerchantOffer offer, @Nullable io.papermc.paper.event.player.PlayerPurchaseEvent event) { this.notifyTrade(offer); } // Paper
+
     void notifyTrade(MerchantOffer offer);
 
     void notifyTradeUpdated(ItemStack stack);
@@ -50,4 +_,6 @@
     boolean isClientSide();
 
     boolean stillValid(Player player);
+
+    org.bukkit.craftbukkit.inventory.CraftMerchant getCraftMerchant(); // CraftBukkit
 }
