The slot data structure is how minecraft represents an item and its associated data in the minecraft protocol
- 0x0F player block placement
- 0x66 window click
- 0x67 set slot
- 0x68 window items (as an array)
- 0x6B creative inventory action
The structure consists of at least a short, which gives the item/block ID . A value of
-1 signifies that the slot is empty, and no further data follows.
For non-empty slots, at least two further fields follow. These fields are a byte (item count) and a short (damage/block metadata)
For certain block IDs, given below, further data follows. First, a short gives the length of a proceeding byte array. A value of
-1 signifies no further data.
The byte array (if present) contains gzipped (that is RFC 1952 rather than RFC 1950) NBT data. The format of this data is as follows:
COMPOUND: '' LIST: 'ench' COMPOUND SHORT: 'id' SHORT: 'lvl' END COMPOUND ...etc END END
Each of the inner, untagged COMPOUNDs represents an enchantment, with its ID and level given as child SHORT elements.
Every item that has a "damage bar" in-game is considered enchantable by the protocol, though the notchian server/client do not support enchantment of some items. These include: hoes, flint and steel, bows, fishing rods and shears.
0x103, #Flint and steel 0x105, #Bow 0x15A, #Fishing rod 0x167, #Shears #TOOLS #sword, shovel, pickaxe, axe, hoe 0x10C, 0x10D, 0x10E, 0x10F, 0x122, #WOOD 0x110, 0x111, 0x112, 0x113, 0x123, #STONE 0x10B, 0x100, 0x101, 0x102, 0x124, #IRON 0x114, 0x115, 0x116, 0x117, 0x125, #DIAMOND 0x11B, 0x11C, 0x11D, 0x11E, 0x126, #GOLD #ARMOUR #helmet, chestplate, leggings, boots 0x12A, 0x12B, 0x12C, 0x12D, #LEATHER 0x12E, 0x12F, 0x130, 0x131, #CHAIN 0x132, 0x133, 0x134, 0x135, #IRON 0x136, 0x137, 0x138, 0x139, #DIAMOND 0x13A, 0x13B, 0x13C, 0x14D #GOLD