Common (Tokens)
Functionality that is common to multiple token standards.
-
ERC2981
: NFT Royalties compatible with both ERC721 and ERC1155.-
For ERC721 consider
ERC721Royalty
which clears the royalty information from storage on burn.
-
Contracts
ERC2981
import "@openzeppelin/contracts/token/common/ERC2981.sol";
Implementation of the NFT Royalty Standard, a standardized way to retrieve royalty payment information.
Royalty information can be specified globally for all token ids via _setDefaultRoyalty
, and/or individually for
specific token ids via _setTokenRoyalty
. The latter takes precedence over the first.
Royalty is specified as a fraction of sale price. _feeDenominator
is overridable but defaults to 10000, meaning the
fee is specified in basis points by default.
ERC-2981 only specifies a way to signal royalty information and does not enforce its payment. See Rationale in the EIP. Marketplaces are expected to voluntarily pay royalties together with sales, but note that this standard is not yet widely supported. |
royaltyInfo(uint256 tokenId, uint256 salePrice) → address, uint256
public
Returns how much royalty is owed and to whom, based on a sale price that may be denominated in any unit of exchange. The royalty amount is denominated and should be paid in that same unit of exchange.
_feeDenominator() → uint96
internal
The denominator with which to interpret the fee set in _setTokenRoyalty
and _setDefaultRoyalty
as a
fraction of the sale price. Defaults to 10000 so fees are expressed in basis points, but may be customized by an
override.
_setDefaultRoyalty(address receiver, uint96 feeNumerator)
internal
Sets the royalty information that all ids in this contract will default to.
Requirements:
-
receiver
cannot be the zero address. -
feeNumerator
cannot be greater than the fee denominator.
_setTokenRoyalty(uint256 tokenId, address receiver, uint96 feeNumerator)
internal
Sets the royalty information for a specific token id, overriding the global default.
Requirements:
-
receiver
cannot be the zero address. -
feeNumerator
cannot be greater than the fee denominator.
_resetTokenRoyalty(uint256 tokenId)
internal
Resets royalty information for the token id back to the global default.
ERC2981InvalidDefaultRoyalty(uint256 numerator, uint256 denominator)
error
The default royalty set is invalid (eg. (numerator / denominator) >= 1).
ERC2981InvalidDefaultRoyaltyReceiver(address receiver)
error
The default royalty receiver is invalid.