ERC-5409: EIP-1155 Non-Fungible Token extension


  Ethereum Improvement Proposals
        
        
          
            
              
            
          
        

        AllCoreNetworkingInterfaceERCMetaInformational

      



      
        
  
    

  
    
      🚧 Stagnant
    
    
    
    
    
      Standards Track: ERC
    
  
  
    
      ERC-5409: EIP-1155 Non-Fungible Token extension
    
    
      
        
      
    
    
      
        
      
    
  

  Allow EIP-1155 to represent Non-Fungible Tokens (tokens who have a unique owner)

  	Authors	Ronan Sandford (@wighawag)
	Created	2022-07-23
	Discussion Link	https://ethereum-magicians.org/t/eip-5409-non-fungible-token-extension-for-eip-1155/10240
	Requires	

  EIP-165, 

  EIP-721, 

  EIP-1155




  


  

  
    Table of Contents

    	Abstract
	Motivation
	Specification
    	Contract Interface


  
	Rationale
	Backwards Compatibility
	Security Considerations
	Copyright



  


  
      
      
         Abstract
      
      
    


This standard is an extension of EIP-1155. It proposes an additional function, ownerOf, which allows EIP-1155 tokens to support Non-Fungibility (unique owners). By implementing this extra function, EIP-1155 tokens can benefit from EIP-721’s core functionality without implementing the (less efficient) EIP-721 specification in the same contract.

  
    
      
      
         Motivation
      
      
    


Currently, EIP-1155 does not allow an external caller to detect whether a token is truly unique (can have only one owner) or fungible. This is because EIP-1155 do not expose a mechanism to detect whether a token will have its supply remain to be “1”. Furthermore, it does not let an external caller retrieve the owner directly on-chain.


The EIP-1155 specification does mention the use of split id to represent non-fungible tokens, but this requires a pre-established convention that is not part of the standard, and is not as simple as EIP-721’s ownerOf.


The ability to get the owner of a token enables novel use-cases, including the ability for the owner to associate data with it.

  
    
      
      
         Specification
      
      
    


The keywords “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “MAY” and “OPTIONAL” in this document are to be interpreted as described in RFC 2119.

  
    
      
      
         Contract Interface
      
      
    


interface IERC1155OwnerOf {

    /// @notice Find the owner of an NFT
    /// @dev The zero address indicates that there is no owner: either the token does not exist or it is not an NFT (supply potentially bigger than 1)
    /// @param tokenId The identifier for an NFT
    /// @return The address of the owner of the NFT
    function ownerOf(uint256 tokenId) external view returns (address);
}





The ownerOf(uint256 tokenId) function MAY be implemented as pure or view.


The supportsInterface method MUST return true when called with 0x6352211e.

  
    
      
      
         Rationale
      
      
    


ownerOf does not throw when a token does not exist (or does not have an owner). This simplifies the handling of such a case. Since it would be a security risk to assume all EIP-721 implementation would throw, it should not break compatibility with contract handling EIP-721 when dealing with this EIP-1155 extension.

  
    
      
      
         Backwards Compatibility
      
      
    


This EIP is fully backward compatible with EIP-1155.

  
    
      
      
         Security Considerations
      
      
    


Needs discussion.

  
    
      
      
         Copyright
      
      
    


Copyright and related rights waived via CC0.


  Citation

  Please cite this document as:

  
  Ronan Sandford (@wighawag), "ERC-5409: EIP-1155 Non-Fungible Token extension [DRAFT]," Ethereum Improvement Proposals, no. 5409, July 2022. [Online serial]. Available: https://eips.ethereum.org/EIPS/eip-5409.






      
    
  

  

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        Ethereum Improvement Proposals (EIPs) describe standards for the Ethereum platform, including core protocol specifications, client APIs, and contract standards.