ERC-721
Non-fungible tokens (NFTs). Wallets show collection + token id in confirmation UIs when you call the contract via eth_sendTransaction.
Approvals
NFTs use two patterns. Single token: approve(to, tokenId) lets to transfer that id. Whole collection: setApprovalForAll(operator, true) lets the operator move any token you own in that contract — treat it like an unlimited ERC-20 approval in the UI.
| Method | What it does |
|---|---|
getApproved(tokenId) | Address allowed to transfer that token, or zero |
isApprovedForAll(owner, operator) | Whether the operator may move any of owner's tokens in this contract |
approve(address(0), tokenId) | Clear per-token approval |
setApprovalForAll(operator, false) | Revoke collection-wide access |