Dieter Shirley (lead author) - ERC-721 non-fungible-token standard ratified

2018

Artists: Dieter Shirley (lead author), William Entriken, Jacob Evans, Nastassia Sachs · Year: 2018 · Medium: Technical standard (EIP-721) · Substrate: Ethereum smart-contract interface specification · Place: Internet / Vancouver, Canada · Institution: Ethereum Improvement Proposals (EIP) process ERC-721 is the technical standard that defines what a non-fungible token is on the Ethereum blockchain. Drafted in 2017 and finalized as an Ethereum Improvement Proposal in early 2018, it was authored primarily by Dieter Shirley, who had worked on CryptoKitties at Axiom Zen, along with William Entriken, Jacob Evans, and Nastassia Sachs. The standard specifies a minimal interface, transfer, ownership check, approval, that every compliant NFT contract implements, which is how OpenSea or any other platform can speak to any NFT collection without knowing that collection's specifics in advance. ERC-721 is infrastructure, not art, but its effects on the art world are total. Before ERC-721, each NFT-adjacent project, CryptoPunks, CryptoKitties, Rare Pepes, used its own custom smart contract logic and could only be traded on marketplaces built specifically for that project. After ERC-721, any two NFT projects could share a marketplace, a wallet, a set of analytics tools, a pricing floor. The network effect this enabled is the reason NFTs became a legible asset class at all. CryptoPunks, notably, predated the standard by six months. Larva Labs retrofitted CryptoPunks to ERC-721 compliance in 2018, a minor technical accommodation that, in retrospect, was critical for the Punks' continued viability as a tradable collection. A non-standard-compliant CryptoPunks would not have participated in the subsequent marketplace ecosystem. The standard's authors, particularly Shirley, remain active in Ethereum infrastructure. Lore Dieter Shirley described ERC-721's authoring as a few months of late-night discussions among the co-authors, with most of the technical detail being about edge cases, how to handle contract-held tokens, how transfers should behave on approval. The EIP was formally ratified in January 2018 and has been amended only in minor ways since. The superseding ERC-1155 standard (2019) added multi-token support but did not replace ERC-721 for single-work art tokens. Sources • EIP-721 specification (eips.ethereum.org/EIPS/eip-721) • Ethereum Foundation, historical EIP archive • Shirley, Dieter, Twitter / Ethereum developer interviews