New ERC Proposal Aims to Formalize Token Metadata JSON Schema

A new draft ERC posted to the Ethereum Magicians forum on November 10, 2026, proposes to formally specify the JSON document returned by tokenURI in ERC-721 and ERC-6909 tokens, and by uri in ERC-1155 tokens. The draft, titled "ERC: Token Metadata JSON Schema," states that most deployed tokens already use this JSON format in practice, but only part of the structure was ever formally specified in an EIP.

Why metadata rendering has been inconsistent across wallets

Per the Ethereum Magicians post, ERC-721 and ERC-1155 originally defined only three metadata fields directly: name, description, and image. Everything else that wallets and marketplaces commonly display — including animation_url, attributes and their display_type values, external_url, and background_color — traces back to a page OpenSea published in 2018, not to the EIPs themselves.

Because that supplementary structure was never part of an approved standard, the proposal states that different clients have filled the gaps inconsistently. The practical result, according to the post, is that the same token can render differently depending on which wallet or marketplace displays it — a discrepancy the new draft is intended to close by codifying the schema that has become de facto standard across the ecosystem.

The draft includes a linked specification file, erc-draft_token_metadata_json.md, hosted on the Ethereum Magicians thread, which lays out the proposed schema in full. The proposal does not, per the posted summary, introduce new on-chain behavior; it targets the off-chain JSON document that tokenURI and uri calls resolve to, rather than any change to the ERC-721, ERC-1155, or ERC-6909 contract interfaces themselves.

What a formal schema would change for builders

If adopted, a formally specified schema would give wallet developers, marketplaces, and token issuers a single reference for which metadata fields are expected and how they should be structured, rather than relying on conventions inherited from a single marketplace's 2018 documentation. That matters for anyone building on NFT standards or integrating token display into a wallet, since inconsistent field interpretation is the kind of gap that produces visibly broken or mismatched token displays across platforms.

The post is a draft proposal on the Ethereum Magicians forum, which functions as a discussion venue that precedes formal EIP numbering; it has not been assigned a draft or final EIP number as of this writing. CoinsCipher has not located a GitHub pull request against the ethereum/EIPs repository tied to this specific draft at publication time. Further progress would be visible through forum replies, a formal EIP draft submission, or client and marketplace implementations adopting the schema.