GUI-API GUIAPI is a simple API for creating menus/GUIs. These menus use a combination of custom inventories, custom items, and custom events in order to create an in-depth menu where the player clicks on a button (custom item) in a GUI (custom inventory) to cause custom events which allow for flexible menus. HumanEntity.openInventory(Inventory) HumanEntity.openWorkbench(Location, boolean) HumanEntity.openEnchanting(Location, boolean) InventoryView.close() To invoke one of these methods, schedule a task using BukkitScheduler.runTask(Plugin, Runnable), which will run the task on the next tick. Also be aware that this is not an exhaustive list, and other methods could potentially create issues as well.