ERC-6551 (token-bound accounts)

ERC-6551 defines a registry that deterministically creates an account address for any ERC-721 token. That address, the token-bound account, is a smart-contract wallet whose owner is simply the current holder of the NFT. It can receive coins, other NFTs and on-chain credentials, and the NFT holder can sign transactions through it. The registry works with existing collections, so no changes to the original NFT contract are needed.

The standard turns an NFT from a single item into a container. Games can give a character its own inventory that travels with it when sold; membership NFTs can accumulate badges and history; brands can bundle several assets into one transferable package. Several wallets and NFT platforms now display token-bound accounts next to the token itself.

The main risk sits in sales. When an NFT changes hands, everything in its account goes with it, so a seller could try to drain the account just before a purchase settles, and buyers must check contents at the moment of transfer. Marketplace and wallet support remains uneven, so assets may be hard to see.