I want to get the offers of the villagers on the client. I assume I can only get them when the player is opening the GUI of a villager but I still can't figure it out.

 

@SubscribeEvent
public void onGuiOpen(GuiOpenEvent event){
  if (event.getGui() instanceof MerchantScreen){
    MerchantScreen gui = (MerchantScreen) event.getGui();
    MerchantContainer container = gui.getContainer();
    System.out.println(container.getOffers());
  }
}

Using this code I get an empty MerchantOffers object.

 

Maybe someone knows a solution to this problem.

GuiOpenEvent is called before the gui is open. You can cancel the event making it apparent that it doesn't load data yet. Use something like GuiContainerEvent on one of the layers to get the client information since the gui will have been initialized to be open.

Ah yes this worked, thanks a lot!