OpenSea serves as a horizontal, peer-to-peer marketplace for digital goods, allowing users to buy, sell, and auction NFTs, rare digital items and crypto collectibles. For developers, OpenSea offers extensive integrations and tooling for dApps in the NFT space. They index and provide the largest dataset of NFTs (having been around since the first projects were listed), and act as a secondary market for popular collections and projects.
OpenSea supports a number of widely-used tokens and chains, and they are actively expanding that list. They support both ERC-721 non-fungibles and ERC-1155 semi-fungibles, and are a multi-chain platform, providing tooling for Polygon and Klaytn in addition to Ethereum.
Alongside their marketplace, OpenSea’s API platform powers third-party tooling, with their REST API serving as the backbone of a number of large projects in the Web3 community, such as MetaMask, Coinbase Wallet, and Rainbow, among others.
OpenSea’s developer tooling consists of a REST API that enables developers to access and display metadata about NFTs, and a Software Development Kit (SDK) that builds on top of the API to enable the development that directly interfaces with the blockchain, such as for the creation of NFT marketplaces via the buying & selling of digital assets. The OpenSea dev platform provides a number of key value-adds.
For the application development via the API:
And for smart contract interaction via the SDK: