> For the complete documentation index, see [llms.txt](https://the-artist-xchange.gitbook.io/the-artist-xchange/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://the-artist-xchange.gitbook.io/the-artist-xchange/docs/erc721base.md).

# ERC721Base

The `ERC721Base` smart contract implements the ERC721 NFT standard, along with the ERC721A optimization to the standard. It includes the following additions to standard ERC721 logic: - Ability to mint NFTs via the provided `mint` function. - Contract metadata for royalty support on platforms such as OpenSea that use off-chain information to distribute roaylties. - Ownership of the contract, with the ability to restrict certain functions to only be called by the contract's owner. - Multicall capability to perform multiple actions atomically - EIP 2981 compliance for royalty support on NFT marketplaces.

## Methods

### OPERATOR\_FILTER\_REGISTRY

```solidity
function OPERATOR_FILTER_REGISTRY() external view returns (contract IOperatorFilterRegistry)
```

#### Returns

| Name | Type                             | Description |
| ---- | -------------------------------- | ----------- |
| \_0  | contract IOperatorFilterRegistry | undefined   |

### approve

```solidity
function approve(address operator, uint256 tokenId) external nonpayable
```

*See {ERC721-approve}.*

#### Parameters

| Name     | Type    | Description |
| -------- | ------- | ----------- |
| operator | address | undefined   |
| tokenId  | uint256 | undefined   |

### balanceOf

```solidity
function balanceOf(address owner) external view returns (uint256)
```

*See {IERC721-balanceOf}.*

#### Parameters

| Name  | Type    | Description |
| ----- | ------- | ----------- |
| owner | address | undefined   |

#### Returns

| Name | Type    | Description |
| ---- | ------- | ----------- |
| \_0  | uint256 | undefined   |

### batchMintTo

```solidity
function batchMintTo(address _to, uint256 _quantity, string _baseURI, bytes _data) external nonpayable
```

Lets an authorized address mint multiple NFTs at once to a recipient.

*The logic in the `_canMint` function determines whether the caller is authorized to mint NFTs.*

#### Parameters

| Name       | Type    | Description                                                                                   |
| ---------- | ------- | --------------------------------------------------------------------------------------------- |
| \_to       | address | The recipient of the NFT to mint.                                                             |
| \_quantity | uint256 | The number of NFTs to mint.                                                                   |
| \_baseURI  | string  | The baseURI for the `n` number of NFTs minted. The metadata for each NFT is `baseURI/tokenId` |
| \_data     | bytes   | Additional data to pass along during the minting of the NFT.                                  |

### burn

```solidity
function burn(uint256 _tokenId) external nonpayable
```

Lets an owner or approved operator burn the NFT of the given tokenId.

*ERC721A's `_burn(uint256,bool)` internally checks for token approvals.*

#### Parameters

| Name      | Type    | Description                     |
| --------- | ------- | ------------------------------- |
| \_tokenId | uint256 | The tokenId of the NFT to burn. |

### contractURI

```solidity
function contractURI() external view returns (string)
```

Returns the contract metadata URI.

#### Returns

| Name | Type   | Description |
| ---- | ------ | ----------- |
| \_0  | string | undefined   |

### getApproved

```solidity
function getApproved(uint256 tokenId) external view returns (address)
```

*See {IERC721-getApproved}.*

#### Parameters

| Name    | Type    | Description |
| ------- | ------- | ----------- |
| tokenId | uint256 | undefined   |

#### Returns

| Name | Type    | Description |
| ---- | ------- | ----------- |
| \_0  | address | undefined   |

### getBaseURICount

```solidity
function getBaseURICount() external view returns (uint256)
```

Returns the count of batches of NFTs.

*Each batch of tokens has an in ID and an associated `baseURI`. See {batchIds}.*

#### Returns

| Name | Type    | Description |
| ---- | ------- | ----------- |
| \_0  | uint256 | undefined   |

### getBatchIdAtIndex

```solidity
function getBatchIdAtIndex(uint256 _index) external view returns (uint256)
```

Returns the ID for the batch of tokens the given tokenId belongs to.

*See {getBaseURICount}.*

#### Parameters

| Name    | Type    | Description    |
| ------- | ------- | -------------- |
| \_index | uint256 | ID of a token. |

#### Returns

| Name | Type    | Description |
| ---- | ------- | ----------- |
| \_0  | uint256 | undefined   |

### getDefaultRoyaltyInfo

```solidity
function getDefaultRoyaltyInfo() external view returns (address, uint16)
```

Returns the defualt royalty recipient and BPS for this contract's NFTs.

#### Returns

| Name | Type    | Description |
| ---- | ------- | ----------- |
| \_0  | address | undefined   |
| \_1  | uint16  | undefined   |

### getRoyaltyInfoForToken

```solidity
function getRoyaltyInfoForToken(uint256 _tokenId) external view returns (address, uint16)
```

View royalty info for a given token.

*Returns royalty recipient and bps for `_tokenId`.*

#### Parameters

| Name      | Type    | Description                                             |
| --------- | ------- | ------------------------------------------------------- |
| \_tokenId | uint256 | The tokenID of the NFT for which to query royalty info. |

#### Returns

| Name | Type    | Description |
| ---- | ------- | ----------- |
| \_0  | address | undefined   |
| \_1  | uint16  | undefined   |

### isApprovedForAll

```solidity
function isApprovedForAll(address owner, address operator) external view returns (bool)
```

*See {IERC721-isApprovedForAll}.*

#### Parameters

| Name     | Type    | Description |
| -------- | ------- | ----------- |
| owner    | address | undefined   |
| operator | address | undefined   |

#### Returns

| Name | Type | Description |
| ---- | ---- | ----------- |
| \_0  | bool | undefined   |

### isApprovedOrOwner

```solidity
function isApprovedOrOwner(address _operator, uint256 _tokenId) external view returns (bool isApprovedOrOwnerOf)
```

Returns whether a given address is the owner, or approved to transfer an NFT.

#### Parameters

| Name       | Type    | Description |
| ---------- | ------- | ----------- |
| \_operator | address | undefined   |
| \_tokenId  | uint256 | undefined   |

#### Returns

| Name                | Type | Description |
| ------------------- | ---- | ----------- |
| isApprovedOrOwnerOf | bool | undefined   |

### mintTo

```solidity
function mintTo(address _to, string _tokenURI) external nonpayable
```

Lets an authorized address mint an NFT to a recipient.

*The logic in the `_canMint` function determines whether the caller is authorized to mint NFTs.*

#### Parameters

| Name       | Type    | Description                               |
| ---------- | ------- | ----------------------------------------- |
| \_to       | address | The recipient of the NFT to mint.         |
| \_tokenURI | string  | The full metadata URI for the NFT minted. |

### multicall

```solidity
function multicall(bytes[] data) external nonpayable returns (bytes[] results)
```

Receives and executes a batch of function calls on this contract.

*Receives and executes a batch of function calls on this contract.*

#### Parameters

| Name | Type     | Description                                                          |
| ---- | -------- | -------------------------------------------------------------------- |
| data | bytes\[] | The bytes data that makes up the batch of function calls to execute. |

#### Returns

| Name    | Type     | Description                                                                      |
| ------- | -------- | -------------------------------------------------------------------------------- |
| results | bytes\[] | The bytes data that makes up the result of the batch of function calls executed. |

### name

```solidity
function name() external view returns (string)
```

*See {IERC721Metadata-name}.*

#### Returns

| Name | Type   | Description |
| ---- | ------ | ----------- |
| \_0  | string | undefined   |

### nextTokenIdToMint

```solidity
function nextTokenIdToMint() external view returns (uint256)
```

The tokenId assigned to the next new NFT to be minted.

#### Returns

| Name | Type    | Description |
| ---- | ------- | ----------- |
| \_0  | uint256 | undefined   |

### operatorRestriction

```solidity
function operatorRestriction() external view returns (bool)
```

#### Returns

| Name | Type | Description |
| ---- | ---- | ----------- |
| \_0  | bool | undefined   |

### owner

```solidity
function owner() external view returns (address)
```

Returns the owner of the contract.

#### Returns

| Name | Type    | Description |
| ---- | ------- | ----------- |
| \_0  | address | undefined   |

### ownerOf

```solidity
function ownerOf(uint256 tokenId) external view returns (address)
```

*See {IERC721-ownerOf}.*

#### Parameters

| Name    | Type    | Description |
| ------- | ------- | ----------- |
| tokenId | uint256 | undefined   |

#### Returns

| Name | Type    | Description |
| ---- | ------- | ----------- |
| \_0  | address | undefined   |

### royaltyInfo

```solidity
function royaltyInfo(uint256 tokenId, uint256 salePrice) external view returns (address receiver, uint256 royaltyAmount)
```

View royalty info for a given token and sale price.

*Returns royalty amount and recipient for `tokenId` and `salePrice`.*

#### Parameters

| Name      | Type    | Description                                             |
| --------- | ------- | ------------------------------------------------------- |
| tokenId   | uint256 | The tokenID of the NFT for which to query royalty info. |
| salePrice | uint256 | Sale price of the token.                                |

#### Returns

| Name          | Type    | Description                                            |
| ------------- | ------- | ------------------------------------------------------ |
| receiver      | address | Address of royalty recipient account.                  |
| royaltyAmount | uint256 | Royalty amount calculated at current royaltyBps value. |

### safeTransferFrom

```solidity
function safeTransferFrom(address from, address to, uint256 tokenId) external nonpayable
```

*See {ERC721-\_safeTransferFrom}.*

#### Parameters

| Name    | Type    | Description |
| ------- | ------- | ----------- |
| from    | address | undefined   |
| to      | address | undefined   |
| tokenId | uint256 | undefined   |

### safeTransferFrom

```solidity
function safeTransferFrom(address from, address to, uint256 tokenId, bytes data) external nonpayable
```

*See {ERC721-\_safeTransferFrom}.*

#### Parameters

| Name    | Type    | Description |
| ------- | ------- | ----------- |
| from    | address | undefined   |
| to      | address | undefined   |
| tokenId | uint256 | undefined   |
| data    | bytes   | undefined   |

### setApprovalForAll

```solidity
function setApprovalForAll(address operator, bool approved) external nonpayable
```

*See {ERC721-setApprovalForAll}.*

#### Parameters

| Name     | Type    | Description |
| -------- | ------- | ----------- |
| operator | address | undefined   |
| approved | bool    | undefined   |

### setContractURI

```solidity
function setContractURI(string _uri) external nonpayable
```

Lets a contract admin set the URI for contract-level metadata.

*Caller should be authorized to setup contractURI, e.g. contract admin. See {\_canSetContractURI}. Emits {ContractURIUpdated Event}.*

#### Parameters

| Name  | Type   | Description                                                  |
| ----- | ------ | ------------------------------------------------------------ |
| \_uri | string | keccak256 hash of the role. e.g. keccak256("TRANSFER\_ROLE") |

### setDefaultRoyaltyInfo

```solidity
function setDefaultRoyaltyInfo(address _royaltyRecipient, uint256 _royaltyBps) external nonpayable
```

Updates default royalty recipient and bps.

*Caller should be authorized to set royalty info. See {\_canSetRoyaltyInfo}. Emits {DefaultRoyalty Event}; See {\_setupDefaultRoyaltyInfo}.*

#### Parameters

| Name               | Type    | Description                                     |
| ------------------ | ------- | ----------------------------------------------- |
| \_royaltyRecipient | address | Address to be set as default royalty recipient. |
| \_royaltyBps       | uint256 | Updated royalty bps.                            |

### setOperatorRestriction

```solidity
function setOperatorRestriction(bool _restriction) external nonpayable
```

#### Parameters

| Name          | Type | Description |
| ------------- | ---- | ----------- |
| \_restriction | bool | undefined   |

### setOwner

```solidity
function setOwner(address _newOwner) external nonpayable
```

Lets an authorized wallet set a new owner for the contract.

#### Parameters

| Name       | Type    | Description                                          |
| ---------- | ------- | ---------------------------------------------------- |
| \_newOwner | address | The address to set as the new owner of the contract. |

### setRoyaltyInfoForToken

```solidity
function setRoyaltyInfoForToken(uint256 _tokenId, address _recipient, uint256 _bps) external nonpayable
```

Updates default royalty recipient and bps for a particular token.

*Sets royalty info for `_tokenId`. Caller should be authorized to set royalty info. See {\_canSetRoyaltyInfo}. Emits {RoyaltyForToken Event}; See {\_setupRoyaltyInfoForToken}.*

#### Parameters

| Name        | Type    | Description                                                |
| ----------- | ------- | ---------------------------------------------------------- |
| \_tokenId   | uint256 | undefined                                                  |
| \_recipient | address | Address to be set as royalty recipient for given token Id. |
| \_bps       | uint256 | Updated royalty bps for the token Id.                      |

### supportsInterface

```solidity
function supportsInterface(bytes4 interfaceId) external view returns (bool)
```

*See ERC165: <https://eips.ethereum.org/EIPS/eip-165>*

#### Parameters

| Name        | Type   | Description |
| ----------- | ------ | ----------- |
| interfaceId | bytes4 | undefined   |

#### Returns

| Name | Type | Description |
| ---- | ---- | ----------- |
| \_0  | bool | undefined   |

### symbol

```solidity
function symbol() external view returns (string)
```

*See {IERC721Metadata-symbol}.*

#### Returns

| Name | Type   | Description |
| ---- | ------ | ----------- |
| \_0  | string | undefined   |

### tokenURI

```solidity
function tokenURI(uint256 _tokenId) external view returns (string)
```

Returns the metadata URI for an NFT.

*See `BatchMintMetadata` for handling of metadata in this contract.*

#### Parameters

| Name      | Type    | Description            |
| --------- | ------- | ---------------------- |
| \_tokenId | uint256 | The tokenId of an NFT. |

#### Returns

| Name | Type   | Description |
| ---- | ------ | ----------- |
| \_0  | string | undefined   |

### totalSupply

```solidity
function totalSupply() external view returns (uint256)
```

*Burned tokens are calculated here, use \_totalMinted() if you want to count just minted tokens.*

#### Returns

| Name | Type    | Description |
| ---- | ------- | ----------- |
| \_0  | uint256 | undefined   |

### transferFrom

```solidity
function transferFrom(address from, address to, uint256 tokenId) external nonpayable
```

*See {ERC721-\_transferFrom}.*

#### Parameters

| Name    | Type    | Description |
| ------- | ------- | ----------- |
| from    | address | undefined   |
| to      | address | undefined   |
| tokenId | uint256 | undefined   |

## Events

### Approval

```solidity
event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId)
```

#### Parameters

| Name               | Type    | Description |
| ------------------ | ------- | ----------- |
| owner `indexed`    | address | undefined   |
| approved `indexed` | address | undefined   |
| tokenId `indexed`  | uint256 | undefined   |

### ApprovalForAll

```solidity
event ApprovalForAll(address indexed owner, address indexed operator, bool approved)
```

#### Parameters

| Name               | Type    | Description |
| ------------------ | ------- | ----------- |
| owner `indexed`    | address | undefined   |
| operator `indexed` | address | undefined   |
| approved           | bool    | undefined   |

### ContractURIUpdated

```solidity
event ContractURIUpdated(string prevURI, string newURI)
```

#### Parameters

| Name    | Type   | Description |
| ------- | ------ | ----------- |
| prevURI | string | undefined   |
| newURI  | string | undefined   |

### DefaultRoyalty

```solidity
event DefaultRoyalty(address indexed newRoyaltyRecipient, uint256 newRoyaltyBps)
```

#### Parameters

| Name                          | Type    | Description |
| ----------------------------- | ------- | ----------- |
| newRoyaltyRecipient `indexed` | address | undefined   |
| newRoyaltyBps                 | uint256 | undefined   |

### OperatorRestriction

```solidity
event OperatorRestriction(bool restriction)
```

#### Parameters

| Name        | Type | Description |
| ----------- | ---- | ----------- |
| restriction | bool | undefined   |

### OwnerUpdated

```solidity
event OwnerUpdated(address indexed prevOwner, address indexed newOwner)
```

#### Parameters

| Name                | Type    | Description |
| ------------------- | ------- | ----------- |
| prevOwner `indexed` | address | undefined   |
| newOwner `indexed`  | address | undefined   |

### RoyaltyForToken

```solidity
event RoyaltyForToken(uint256 indexed tokenId, address indexed royaltyRecipient, uint256 royaltyBps)
```

#### Parameters

| Name                       | Type    | Description |
| -------------------------- | ------- | ----------- |
| tokenId `indexed`          | uint256 | undefined   |
| royaltyRecipient `indexed` | address | undefined   |
| royaltyBps                 | uint256 | undefined   |

### Transfer

```solidity
event Transfer(address indexed from, address indexed to, uint256 indexed tokenId)
```

#### Parameters

| Name              | Type    | Description |
| ----------------- | ------- | ----------- |
| from `indexed`    | address | undefined   |
| to `indexed`      | address | undefined   |
| tokenId `indexed` | uint256 | undefined   |

## Errors

### ApprovalCallerNotOwnerNorApproved

```solidity
error ApprovalCallerNotOwnerNorApproved()
```

The caller must own the token or be an approved operator.

### ApprovalQueryForNonexistentToken

```solidity
error ApprovalQueryForNonexistentToken()
```

The token does not exist.

### ApprovalToCurrentOwner

```solidity
error ApprovalToCurrentOwner()
```

The caller cannot approve to the current owner.

### ApproveToCaller

```solidity
error ApproveToCaller()
```

The caller cannot approve to their own address.

### BalanceQueryForZeroAddress

```solidity
error BalanceQueryForZeroAddress()
```

Cannot query the balance for the zero address.

### MintToZeroAddress

```solidity
error MintToZeroAddress()
```

Cannot mint to the zero address.

### MintZeroQuantity

```solidity
error MintZeroQuantity()
```

The quantity of tokens minted must be more than zero.

### OperatorNotAllowed

```solidity
error OperatorNotAllowed(address operator)
```

#### Parameters

| Name     | Type    | Description |
| -------- | ------- | ----------- |
| operator | address | undefined   |

### OwnerQueryForNonexistentToken

```solidity
error OwnerQueryForNonexistentToken()
```

The token does not exist.

### TransferCallerNotOwnerNorApproved

```solidity
error TransferCallerNotOwnerNorApproved()
```

The caller must own the token or be an approved operator.

### TransferFromIncorrectOwner

```solidity
error TransferFromIncorrectOwner()
```

The token must be owned by `from`.

### TransferToNonERC721ReceiverImplementer

```solidity
error TransferToNonERC721ReceiverImplementer()
```

Cannot safely transfer to a contract that does not implement the ERC721Receiver interface.

### TransferToZeroAddress

```solidity
error TransferToZeroAddress()
```

Cannot transfer to the zero address.

### URIQueryForNonexistentToken

```solidity
error URIQueryForNonexistentToken()
```

The token does not exist.