📜 EIP-2981: The Royalty Standard

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface IERC2981 {
    /// @notice Called with the sale price to determine royalty amount
    /// @param tokenId - the NFT asset queried for royalty information
    /// @param salePrice - the sale price of the NFT asset
    /// @return receiver - address of who should receive royalty
    /// @return royaltyAmount - the royalty payment amount for salePrice
    function royaltyInfo(
        uint256 tokenId,
        uint256 salePrice
    ) external view returns (
        address receiver,
        uint256 royaltyAmount
    );
}