NFT Marketplace Royalty Standards (EIP-2981) 2

Question 1

What does the royaltyInfo function in EIP-2981 return?

Accepted Answer

The receiver address and the royalty amount

Answer

royaltyInfo(tokenId, salePrice) returns a tuple of the receiver address and the royaltyAmount to pay.

Question 2

Which parameters does royaltyInfo accept?

Accepted Answer

_tokenId and _salePrice

Answer

royaltyInfo takes the token ID and the sale price, then computes the royalty owed.

Question 3

EIP-2981 specifies royalty information but does NOT do what?

Accepted Answer

Enforce or transfer the royalty payment

Answer

EIP-2981 only signals the amount and receiver; actual payment enforcement is left to the marketplace.

Question 4

How is EIP-2981 support advertised to other contracts?

Accepted Answer

Via ERC-165 supportsInterface

Answer

Contracts implement ERC-165 so marketplaces can detect the IERC2981 interface ID.

Question 5

In what unit is royaltyAmount denominated?

Accepted Answer

The same unit of exchange as _salePrice

Answer

royaltyAmount is expressed in the same currency/unit as the salePrice passed in.

NFT Development Practice Test