/goop nbt copy <player> <slots> <source-slot> [±][amount][%]
All the items in the target slots will be replaced with the item in the source slot.
Player whose inventory items' NBT will be edited.
Supports a few vanilla selectors.
May be an Entity (dropped item) UUID
The slot in the player's inventory in which items will be transmutated. To read on slots see Inventory Slots.
Examples: mainhand, offhand, chest, feet, any, 0-8, ec*
Slot of the item to copy.
The operation to apply to the amount of the item about to be replaced. See Plus Minus Percent page for full explanation.
Default is 1, setting one item of that type in the target slot.
If there already was an item in the target slot, it will be lost.
The only information of it that may be left is its amount. See the point below.
You may convert already existing items into a new item by setting the operation to +0
This will keep the original amount, so none will be lost
/goop nbt copy cln89 head mainhand
Puts the item in the hand of cln89 on his head.
/goop nbt setItem %player% c13 %provided-slot% 10
Sets the item in the container slot #13 to whatever item is in the slot the player clicked, but the amount of the copied stack will be set to ten.