How to build a NFT Marketplace with verifiable offchain metadata
There are two features that are the most important besides smart contracts for a NFT marketplace that are easy but gets complex when it is about to scale:
1 - Distribution
2 - Fees and royalties
Becase a NFT publisher does not create one rare item per year, they actually have collections, NFT distribution is an art itself. There is the Voucher technique recommended by NFTSchool.dev, we actually had an Ancon Protocol in Cosmos SDK that used this design pattern.
It means that you first batch NFTs with a signature, offchain, and then its vouched when a first sale occurs.
Fees and royalties
Additionally, you might be a bargain collector which resells to others in second hand markets. Where do you keep track of these exchanges besides the origin contract chain, as fees & royalties storage? You could use blockchain, but considering the gas costs, say you want to give a discount on 1 million NFTs, for that you need databases, like Opensea does, but this is not decentralized.
Enter Ancon Protocol
As a publisher, you first register / claim a DID account seamlessly with your wallet. (Kind of ERC-4337 but similar, we’ll support it Q2).
Because the transfer ownership proof is requested offchain with trusted data retrieval gateway, you can apply the same to obtain fees and royalties from DAG stores in a verifiable and decentralized way.