isApprovedForAll

IsApprovedForAll is a view function defined in the ERC-721 standard (and implemented by ERC-721 compatible contracts) that reports whether an address is an operator authorized to manage all tokens of a given owner. Its signature is isApprovedForAll(address owner, address operator) external view returns (bool). The function returns true when the operator has been granted blanket approval to handle all of the owner’s tokens, and false otherwise.

Approval for all is granted via setApprovalForAll(address operator, bool approved) called by the token owner. When approved is set to true, the operator is recorded in a data structure (typically a mapping) indicating a blanket permission; the operator may then call transferFrom or safeTransferFrom for any of the owner’s tokens. If set to false, the operator loses that blanket permission. The ApprovalForAll event is emitted when setApprovalForAll is invoked, enabling off-chain observers to track approval status.

isApprovedForAll is distinct from per-token approvals granted by approve(address to, uint256 tokenId), which authorize only a single token. A given operator can be both approved for all and approved for individual tokens; isApprovedForAll will reflect the blanket status regardless of per-token approvals.

In usage, wallets and marketplaces frequently query isApprovedForAll to determine whether they can transfer tokens on behalf of an owner without requiring per-token approvals. Implementations may vary in details, but the standard behavior is to use isApprovedForAll for read access to the operator-approval state.