InventoryTransaction

Legacy use-item/placement packet. Inventory and crafting moves went through ItemStackRequest long ago; only the UseItem transaction family still carries meaningful traffic.

inventory-transaction.bin

struct InventoryTransaction {
  varint32                                     LegacyRequestId;
  optional byte + list[LegacySetSlot]          LegacySetItemSlots;
  TransactionData                              Transaction;
}

Structure

Field	Type	Description
Legacy Request Id	varint32
Legacy Set Item Slots	optional byte + list[LegacySetSlot]	Presence flag on the wire; value omitted when absent.
Transaction	TransactionData

Structure of LegacySetSlot

Field	Type	Description
Container Enum	ContainerEnumName
Slots	byte[]

Notes

Types: 0 Normal, 1 Mismatch, 2 UseItem, 3 UseItemOnEntity, 4 ReleaseItem.
Normal/mismatch transactions are treated as violations by servers that enforce server-side inventory.
The legacy request id/slots pair exists for backwards compatibility with pre-1.16 clients.