Abstract

In this standard, a non-fungible token stands as atomic existence and encourages layers of abstraction built on top of it. Ideal for representing concepts like rights, a form of abstract ownership. Such right can take the form of NFT options, oracle membership, virtual coupons, etc., and can then be made liquid because of this tokenization.

Motivation

Non-fungible tokens are popularized by the ERC-721 NFT standard for representing "ownership over digital or physical assets". Over the course of development, reputable NFT projects are about crypto-assets, digital collectibles, etc. The proposed standard aims to single out a special type of NFTs that are ideal for representing abstract ownership such as rights. Examples include the right of making a function call to a smart contract, an NFT option that gives the owner the right, but not obligation, to purchase an ERC-721 NFT, and the prepaid membership (time-dependent right) of accessing to data feeds provided by oracles without having to pay the required token fees. An on-chain subscription business model can then be made available by this standard. The conceptual clarity of an NFT is hence improved by this standard.

Specification

interface IERC3754 {
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    function balanceOf(address owner) external view returns (uint256);
    function ownerOf(uint256 tokenId) external view returns (address);
    function approve(address to, uint256 tokenId) external;
    function getApproved(uint256 tokenId) external view returns (address);
    function setApprovalForAll(address operator, bool approved) external;
    function isApprovedForAll(address owner, address operator) external view returns (bool);
    function transferFrom(address from, address to, uint256 tokenId) external;
    function safeTransferFrom(address from, address to, uint256 tokenId) external;
    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) external;
}

Rationale

The NFTs defined in the ERC-721 standard are already largely accepted and known as representing ownership of digital assets, and the NFTs by this standard aim to be accepted and known as representing abstract ownership. This is achieved by allowing and encouraging layers of abstract utilities built on top of them. Ownership of such NFTs is equivalent with having the rights to perform functions assigned to such tokens. Transfer of such rights is also made easier because of this tokenization. To further distinguish this standard from ERC-721, data fields and functions related to URI are excluded.

Backwards Compatibility

There is no further backwards compatibility required.

Reference Implementation

https://github.com/simontianx/ERC3754

Security Considerations

The security is enhanced from ERC721, given tokens are minted without having to provide URIs. Errors in dealing with URIs can be avoided.

Copyright

Copyright and related rights waived via CC0.