Listings

A listing is an order (standard or cosigned) to sell an NFT once filled by a taker. Listings are gaslessly signed off-chain by the owner/seller of the NFT.

Notional Exchange Listing Flow

1. Maker browses their items and selects an item to list for sale.
2. Maker inputs: Listing Currency/Payment Method, Price, Validity Time.
3. Maker prompted to acknowledge/accept maker marketplace fee percentage and on-chain royalty fee (display sale price, fees, and net seller proceeds)
4. Maker prompted to decide on standard order (on-chain cancellations) or co-signed order (gasless cancellation).
5. Signature Prompt for SaleApproval signature.
6. Order and signature submitted to order book.

Sale Approval

When listing an individual NFT for sale the seller/maker MUST be prompted by the exchange to sign an EIP-712 sale approval in the following format. If the order is a standard order cosigner MUST be set to address(0), for cosigned orders cosigner is set to the address that will cosign the order at time of fulfillment. The exchange MUST submit the signature and order data to an integrated order book via its API(s).

SaleApproval(
    uint8 protocol,
    address cosigner,
    address seller,
    address marketplace,
    address fallbackRoyaltyRecipient,
    address paymentMethod,
    address tokenAddress,
    uint256 tokenId,
    uint256 amount,
    uint256 itemPrice,
    uint256 expiration,
    uint256 marketplaceFeeNumerator,
    uint256 maxRoyaltyFeeNumerator,
    uint256 nonce,
    uint256 masterNonce
)