# Extensions Functions These functions are functions called by extensions built for ERC721 and ERC1155 Creator Contracts ## General Functions
tokenExtension *Get the extension that minted the specified token. If not minted by a token, will return the `0x0` address* ***Permissions:** Public function callable by anyone.* ```solidity function tokenExtension(uint256 tokenId) external view returns (address) ```
## Extension Mangement Functions used to manage installed extensions
getExtensions *Gets a list of all registered extensions.* ***Permissions:** Public function callable by anyone.* ```solidity function getExtensions() view returns (address[] memory extensions) ```
registerExtension *Registers an extension, allowing it to access the mint function, and ability to set a token’s metadata URI or a base URI for that extension. The token URI for tokens minted by this extension will be baseURI\. When registering an extension you can specify a third boolean parameter of "true" for baseURIIdentical to specify the token URI for all tokens to be identical (will not increment with appended tokenId).* ***Permissions:** Owner/Admin function callable by contract owner only.* ```solidity function registerExtension(address extension, string calldata baseURI, bool baseURIIdentical)s, baseURI (string), baseURI (string) function registerExtension(address extension, string calldata baseURI) ```
unregisterExtension *Unregisters an extension and removes access to the mint function and all other extension capabilities.* ***Permissions:** Owner/Admin function callable by contract owner only.* ```solidity function unregisterExtension(address extension) ```
blacklistExtension *Blacklists an extension, preventing future registrations of the address. This function also destroys all references to metadata associated with tokens created by this extension, making them effectively useless.* ***Permissions:** Owner/Admin function callable by contract owner only.* ```solidity function blacklistExtension(address extension) ```
setApproveTransferExtension *Set the overall contract's approve transfer extension (See how to* [*Receive a Transfer Callback here*](https://docs.manifold.xyz/manifold-for-developers/smart-contracts/manifold-creator/contracts/extensions)*). Applies to all tokens in the contract and takes precedent over any extension level approve transfer functionality.*\ \ *Unset by setting the extension to the 0x0 address.* ***Permissions:** Owner/Admin function callable by contract owner only.* ```solidity function setApproveTransferExtension(address extension) ```
setRoyaltiesExtension Override the royalties for all tokens minted by the specified extension ***Permissions:** Owner/Admin function callable by contract owner only.* ```solidity function setRoyaltiesExtension(address extension, address payable[] calldata receivers, uint256[] calldata basisPoints) ```
## Extension Metadata Functions Functions used by extensions to set the metadata of tokens minted by the extension
setBaseTokenURIExtension *Sets the base URI for any tokens minted from this extension. Once set, the metadata URI will be base\_uri/\ by default.* ***Permissions:** Only callable by an extension* ```solidity function setBaseTokenURIExtension(string calldata uri) ```
setTokenURIPrefixExtension *Sets a prefix for all tokens minted from this extension. If configured, and a token has a URI set, tokenURI will return \\.* ***Permissions:** Only callable by an extension* ```solidity function setTokenURIPrefixExtension(string calldata prefix) ```
setTokenURIExtension *Set the tokenURI for a specific token minted from this extension. Useful if you want to do something with a dynamic metadata server and need sequential numbering of tokens. Various methods defined below.* ***Permissions:** Only callable by an extension and only on token minted by the extension* ```solidity function setTokenURIExtension(uint256 tokenId, string calldata uri) external function setTokenURIExtension(uint256[] memory tokenId, string[] calldata uri) ```
## Extension Logic Overriding The powerful thing about Manifold Creator is the ability for extensions to fully override core functionality of NFT smart contracts. The following is a list of functionality extensions can override. ### Metadata Handling An extension can fully manage the token metadata logic by implementing the [ICreatorExtensionTokenURI ](https://github.com/manifoldxyz/creator-core-solidity/blob/main/contracts/extensions/ICreatorExtensionTokenURI.sol)interface. If an extension implements this interface then all metadata logic will be deferred to the extension's `tokenURI` function. ### Token Transfer Approval An extension can control whether or not a token can be transferred. To do this, the extension must implement the [IERC721CreatorExtensionApproveTransfer ](https://github.com/manifoldxyz/creator-core-solidity/blob/main/contracts/extensions/ERC721/IERC721CreatorExtensionApproveTransfer.sol)interface (for ERC721) or the [IERC1155CreatorExtensionApproveTransfer ](https://github.com/manifoldxyz/creator-core-solidity/blob/main/contracts/extensions/ERC1155/IERC1155CreatorExtensionApproveTransfer.sol)interface (for ERC1155). If an extension implements this interface, by default, all transfers will call the extension's `approveTransfer` function prior to every token transfer. An extension can enable/disable this by calling the [setApproveTransferExtension ](#setapprovetransferextension)function. ### **Token Burn Callback** An extension can receive a callback whenever a token is burned. To do this, the extension must implement the [IERC721CreatorExtensionBurnable ](https://github.com/manifoldxyz/creator-core-solidity/blob/main/contracts/extensions/ERC721/IERC721CreatorExtensionBurnable.sol)interface (for ERC721) or the [IERC1155CreatorExtensionBurnable ](https://github.com/manifoldxyz/creator-core-solidity/blob/main/contracts/extensions/ERC1155/IERC1155CreatorExtensionBurnable.sol)interface (for ERC1155). If an extension implements this interface, every time a token is burned it will call the extension's `onBurn` function. ### Royalties An extension can define the royalties for any tokens they mint. To do this, the extension must implement the [ICreatorExtensionRoyalties ](https://github.com/manifoldxyz/creator-core-solidity/blob/main/contracts/extensions/ICreatorExtensionRoyalties.sol)interface. If an extension implements this interface, the Creator Contract will defer all royalty lookups to the extension for tokens minted by it. ## Minting These are functions used by extensions to mint NFTs. NFTs minted by the extension will adhere to the extension's overriding logic. ### ERC721
mintExtension *Mints a token from the extension. Also can set token URI or token data (immutable for a token) if desired.* *Token Data is useful if you wish to store additional data needed by the extension at no additional cost (e.g. mint ordering data).* ***Permissions:** Only callable by an installed extension* ```solidity function mintExtension(address to) returns (uint256) function mintExtension(address to, string calldata uri) returns (uint256) function mintExtension(address to, uint80 data) returns (uint256) ```
mintExtensionBatch *Batch mints tokens from the extension. Also can set token URI or token data (immutable for a token) if desired.* *Token Data is useful if you wish to store additional data needed by the extension at no additional cost (e.g. mint ordering data).* ***Permissions:** Only callable by an installed extension* ```solidity function mintExtensionBatch(address to, uint16 count) returns (uint256[] memory) function mintExtensionBatch(address to, string[] calldata uris) returns (uint256[] memory) function mintExtensionBatch(address to, uint80[] calldata data) returns (uint256[] memory) ```
### ERC1155
mintExtensionNew *Mints a completely new token with the given amount from an extension. If URI is empty, URI will fall back to the default URI configured.* ***Permissions:** Only callable by an installed extension* ```solidity function mintExtensionNew(address[] calldata to, uint256[] calldata amounts, string[] calldata uris) returns (uint256[] memory) ```
mintExtensionExisting *Mints more of an existing token from the extension. Requires that the original token already exist and that it is not a token from an extension.* ***Permissions:** Only callable by an installed extension* ```solidity function mintExtensionExisting(address[] calldata to, uint256[] calldata tokenIds, uint256[] calldata amounts) ```
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