Glossary
ERC-6551
Token Bound Accounts: a standard that gives every ERC-721 NFT its own smart-contract account, letting an NFT hold assets and execute transactions.
ERC-6551, finalized in 2023, defines a registry that deterministically deploys a smart-contract account for any given ERC-721 token. The account is owned by whoever owns the NFT; if the NFT is transferred, control of the account transfers with it.
The pattern enables NFTs that hold their own assets (inventory for a character, vault for a sub-DAO), NFTs that interact with other contracts directly, and composable NFT-of-NFTs hierarchies. Sapienz, Future Primitive, and several game studios were early adopters.