CIP-25

Overview

Meaning and scope

CIP-25 is Cardano’s media token metadata standard for associating native assets with descriptive fields stored in minting transaction metadata. The asset itself remains a native ledger object; the metadata association is interpreted by wallets, marketplaces, and indexers. CIP-25 is best suited to mostly static metadata and is not directly inspectable by Plutus validators in the same way as datum-based state.

Mechanism and operation

CIP-25 defines a widely used metadata structure for Cardano native assets, especially NFTs and media tokens. The metadata is placed under label 721 in a minting transaction and organized by policy ID and asset name, with fields such as name, image, media type, and additional properties. Implementers should follow the active version’s encoding rules, preserve exact policy and asset identifiers, and validate referenced content. CIP-25 should be implemented against an exact document revision, status, and activation context. Conformance to CIP-25 requires more than matching a field name or example. Teams adopting CIP-25 should track errata, compatibility changes, and the deployed software versions that enforce it.

Practical payment example

A Cardano marketplace reads NFT metadata attached to a mint transaction under CIP-25 conventions. It verifies policy and asset identifiers before rendering the artwork, while keeping descriptive metadata separate from proof of ownership.

Operational checks

For Cardano assets, verify that the metadata comes from the correct minting policy and asset name, and identify the CIP-25 version used by the issuer. Display metadata as descriptive material, not ownership proof or an assurance that the referenced image URL will remain available. NFT payment validation still requires the actual token transfer.

Distinctions and limits

They should not assume off-chain URLs remain available or that metadata proves copyright, authenticity, or issuer identity. CIP-25 standardizes discoverable Cardano asset metadata, but applications must still verify identifiers, content availability, and authenticity.

Related reading

Related definitions: transaction.