AuthorizationState

Return whether the EIP-3009 authorization identified by (authorizer, nonce) has been used or cancelled.

func AuthorizationState(
    contractAddress string,
    authorizer string,
    nonce [32]byte, // the bytes32 nonce that was chosen when the authorization was created
) (bool, error)

nonce is a required parameter because the EIP-3009 contract stores a mapping(address => mapping(bytes32 => bool)). Both the authorizer address and the nonce are needed to identify a specific authorization.

func main() {
    ...
    alchemy := gas.NewAlchemy(setting)
    ...
    var nonce [32]byte
    // populate nonce with the bytes32 value used when submitting the authorization
    used, err := alchemy.StableCoin.AuthorizationState(contractAddress, authorizerAddress, nonce)
}