Introduction to CW721 NFTs

NFT is a very hot keyword on search engines in recent years on the topic of digital assets. It is a fun fact that many of us know NFT before we know anything about blockchain.

So what exactly is NFT?

NFTs (non-fungible tokens) are unique cryptographic tokens that exist on a blockchain and cannot be replicated. NFTs can represent real-world items like artwork and real estate. "Tokenizing" these real-world tangible assets makes buying, selling, and trading them more efficient while reducing the probability of fraud.

NFTs are not stored in the user's wallet, instead, each NFT lives in a NFT contract. The NFT contract works as a bookkeeper, this is: it is in charge of handling the creation, storage and transfers of NFTs.

Many other blockchains have added or planned to add support for NFTs. ERC-721 was the first standard for representing non-fungible digital assets on the Ethereum blockchain.

So what is CW721?

On Cosmwasm, in order for a contract to be considered a NFT-contract it has to follow the CW721 specification.

CW721 is a specification for non-fungible tokens based on CosmWasm. The name and design is based on Ethereum's ERC721 standard, with some enhancements. The types in here can be imported by contracts that wish to implement this spec, or by contracts that call to any standard CW721 contract.

This short article is intended as a brief introduction for the reader to understand what NFT is and to know about the CW721 standard. If you want to read it in more detail, refer to the repo CW721 spec on Github.