xls: 61
  title: CrossCurrency NFTokenAcceptOffer
  description: Allow cross-currency NFToken transactions using multiple currencies
  author: tequ (@tequdev)
  created: 2024-02-26
  status: Stagnant
  category: Amendment

Abstract¶

XRPL's NFToken functionality, currently implemented as XLS-20, only allows the use of a single currency for transactions.

This proposal allows cross-currency NFToken transactions using multiple currencies.

Creators and marketplaces will be able to sell NFTs without being tied to a currency, and users will be able to buy NFTs without being tied to a currency.

This will increase revenue opportunities for creators and marketplaces and create significant tokenomics.

Specification¶

NFTokenAcceptOffer Transaction¶

Add the following field:

Field Name	Required?	JSON Type	Internal Type
Amount		object or string	AMOUNT

Amount Field¶

When accepting an NFTokenOffer with the tfSellOffer flag set, the Amount field acts like the SendMax field, and when accepting an NFTokenOffer without tfSellOffer set, the DeliverMin field acts like the Amount field.

It doesn't have to match the Amount of the Offeror specified in NFTokenSellOffer or NFTokenBuyOffer.

In broker mode, the Amount field must not be present.

NFTokenBrokerFee Field¶

The existing NFTokenBrokerFee field can be any currency amount.

CrossCurrency Accept¶

The currency of Amount can be different from the currency of the BuyOffer / SellOffer. The currency of NFTokenBrokerFee can be different from the currency of the BuyOffer / SellOffer.

Buyer must specify a sufficient amount that can be transferred to Seller, nftoken issuer(nftoken transfer fee), broker(broker fee), token issuer(token transfer fee).

NFToken transfer fees are sent in the buyer's currency. NFToken with the tfOnlyXRP flag set will be paid in XRP.

If there was insufficient amount or liquidity, the transaction will fail.

NFTokenCreateOffer Transaction¶

No change in fields.

Change to only check if the NFToken issuer has a trustline for the currenfy of Amount field when creating a BuyOffer for an NFToken with royalties.

The NFTokenPage Object¶

No changes.

The NFTokenOffer Object¶

No changes.

Cases¶

Amount Field not specified in NFTokenAcceptOffer Transaction¶

According to XLS-20 specifications. Except for NFTs with royalties, issuer's trust line must be checked.

Amount Field specified and equal to Amount in NFTokenOffer¶

DEX liquidity will not be used and existing transfer processing will be used. If the quantity in the Amount cannot be sent to the seller, the transaction will fail.

Amount Field specified and not same as Amount in NFTokenOffer¶

DEX liquidity will be used and other transfer processing (used in Payment/CheckCash) will be used. If the quantity in Amount cannot be sent to the seller, the transaction will fail.

If the buyer's Amount can send more than the specified amount of the seller's Amount, the amount will be sent up to the maximum amount of the buyer's Amount.

NFTokenBrokerFee Field specified¶

Convert and send the amount from the buyer's Amount to satisfy the NFTokenBrokerFee.

Accept NFToken with TransferFee¶

Paid in the same currency as the buyer's Amount. If no trustline is set, the transaction will fail.

Accept NFToken with TransferFee, tfOnlyXRP, Amount Field specified, NFTokenBrokerFee Field specified¶

Up to 3 times currency will be converted and up to 3 times token transfer fees will be charged.

1. From Buyer to Broker (NFTokenBrokerFee currency, Buyer's Amount currency fee)
2. From Buyer to Issuer (TransferFee currency or XRP, Buyer's Amount currency fee)
3. From Buyer to Seller (Amount currency, Buyer's Amount currency fee)

Concern¶

Transaction load¶

Processing load is expected to increase due to up to three cross-currency remittance processes (flows) within a single transaction.

However, instead of merely being concerned about the increased load of a single transaction, it should be noted that in the current, similar processing would have to be spread over two or more transactions, NFTokenAccept and CrossCurrency Payment.

Royalty for NFToken with tfOnlyFlag¶

The royalty is sent by converting a portion of the buyer's Amount (TransferFee %) into XRP, so if there is not enough liquidity, the royalty might be almost zero.

Note¶

The process used by Payment is used for currency conversion and remittance processing. Path cannot be specified, and only direct AAA->BBB pairs are used at this time.

If auto-bridge is enabled by default by XLS-60d, the auto-bridge path will also be used for the currency conversion process in this proposal.