CW721

Overview

CW721 adapts common non-fungible-token functionality to CosmWasm contracts. It defines messages and queries for token ownership, transfers, sends to contracts, operator approvals, token metadata, enumeration, and optional minting or extension fields. Each NFT collection is identified by its chain and contract address. Token IDs are meaningful within that contract, while metadata can be stored directly or referenced externally. Optional extensions mean two CW721-compatible contracts can expose different administrative and metadata behavior. Wallets and marketplaces should verify collection contracts, current owner, approvals, transfer hooks, and metadata sources. Receiving contracts must authenticate the sending CW721 contract and token ID. Displayed images or names do not prove provenance, rights, or permanence without additional verification.

Implementations should validate normative requirements, encodings, error behavior, security conditions, and test vectors, including malformed and boundary inputs that ordinary happy-path tests miss. Conformance to CW721 requires more than matching a field name or example. Teams adopting CW721 should track errata, compatibility changes, and the deployed software versions that enforce it. A published standard does not prove universal adoption, safe implementation, or activation on a particular blockchain or payment network.

This allows reproducible debugging when a later upgrade changes parsing, validation, signing, or interoperability behavior. Operational records for CW721 should retain the version and configuration used for each relevant transaction or message. CW721 should be implemented against an exact document revision, status, and activation context. Draft, final, optional, and network-activated specifications have different authority, and similarly named deployments may support different subsets or extensions. Practical implication: CW721 standardizes CosmWasm NFT interactions, but contract identity, extensions, ownership, approvals, and metadata still require verification.