safeTransferFromaddress

SafeTransferFromaddress refers to the safeTransferFrom function in the ERC-721 non-fungible token standard. It is the mechanism by which a token is moved from one address to another while taking steps to ensure the recipient can handle NFTs.

Two overloads exist: safeTransferFrom(address from, address to, uint256 tokenId) external and safeTransferFrom(address from, address to, uint256 tokenId, bytes data) external. In both cases, msg.sender must be the current token owner, an approved address for that token, or an operator approved for all of from’s tokens. The from address must own the token, the to address must be a valid recipient, and the tokenId must be owned or approved for transfer.

A key safety feature is the recipient check. If to is a contract, the function calls onERC721Received on the recipient with parameters (operator, from, tokenId, data). The recipient must return the magic value 0x150b7a02 to accept the transfer. If the recipient contract does not implement IERC721Receiver correctly or the call fails, the transfer reverts. This prevents tokens from being accidentally locked in contracts that do not recognize ERC-721 tokens.

SafeTransferFrom differs from transferFrom by adding this recipient verification step. transferFrom only enforces ownership and approvals without ensuring the receiving address can handle ERC-721 tokens, which can lead to tokens being held by non-compliant contracts.

In practice, safeTransferFrom is used to move NFTs with additional data support and to reduce the risk of tokens becoming inaccessible in non-compliant contracts.