OpenSea uses the Wyvern Protocol as its guiding smart contract logic. It operates based on the Ethereum blockchain and allows the minting and trading of NFTs created in compliance with the ERC721/ERC1155 standards of Ethereum. Besides, OpenSea features cross-chain NFT transactions due to its architectural compatibility with the Polygon and Klatyn blockchains. An advantage for artists is OpenSea’s gas-free Polygon marketplace, allowing free NFT minting.