Ethereum

Key	Type	Description
type	string	The type of token (e.g. "NFT" for non-fungible token, "FT" for fungible token, etc.)
contract	string	The unique identifier of a smart contract holding the asset
assetId	string	The unique identifier of the asset class that the token belongs to
tokenId	string	The unique identifier of the specific token instance
standard	string	The ERC standard that the token complies with, if applicable

"ethereum":{
  "type": "NFT",
  "contract": "0xABC",
  "assetId": "xyz456",
  "tokenId": "abc123",
  "standard": "ERC-721"
}