Here is NFT data model used by Rarible API. You can check data model in API Reference
NFT is represented by data model named Item

Field	Type	Description
id	string	identifier of the NFT, format is `${blockchain}:${token}:${tokenId}`
blockchain	enum	"ETHEREUM" "POLYGON" "FLOW" etc...
collection	string	collection identifier
meta	object (Metadata)	Metadata of the NFT
contract	string	contract address, format is `${blockchain}:${address}`. Optional: won't be present for some blockchains (e.g. Solana)
tokenId	string	token identifier. Optional: won't be present for some blockchains (e.g. Solana)
lazySupply	string (BigInteger)	supply for this NFT which is not yet minted on-chain
supply	string (BigInteger)	total supply for this NFT (on-chain and lazy). Can be more than 1 for multiple NFTs (e.g. ERC-1155)
mintedAd	string (date-time)	Date and time when NFT was minted
lastUpdatedAt	string (date-time)	Date and time when NFT was updated
bestSellOrder	object (Order)	Cheapest listing Order
bestBidOrder	object(Order)	Highest (most expensive) Bid for the NFT
totalStock	string (BigInteger)	Total number of NFTs on sale
lastSale	object (ItemLastSale)	information about last sale of this NFT
suspicious	boolean	true if NFT is marked suspicious on any platform

* Fields marked with bold are required

Field	Type	Description
name	string	Name of the NFT
description	string	Description
originalMetaUri	string	Link to original metadata
attributes	array of pairs	List of attributes (traits) NFT has with keys and values
content	array of content	List of content bundled with this NFT (image, video etc)

* Fields marked with bold are required

Field	Type	Description
@type	enum	IMAGE, VIDEO, AUDIO, MODEL_3D, HTML
width	integer	Width of the image or video
height	integer	Height of the image or video
fileName	string	Name of the original file
url	string	Url to access the content
representation	enum	"PREVIEW" "BIG" "ORIGINAL" "PORTRAIT" There can be different versions of the content
mimeType	string	Mime-type of the content
size	integer (int64)	Size of the file
available	boolean	TBD

* Fields marked with bold are required