So, i'm trying to make a "puzzle" mod and i have a "locked" chest, that you can only open using /chest <password>, i already did the player open the chest, but i want to get the contents (items) and check if there is a specific item, if does then do x, if doesn't then do y
edit: it's not a custom gui, it's a chest in the puzzle map // sorry bad english, using translator
edit2: i just solved.. ty