OpenSea

About OpenSea

OpenSea provides an API for accessing NFT, token, and marketplace data across supported blockchains. It covers account, collection, NFT, contract, and token lookups, along with search functionality across the OpenSea ecosystem. The API also supports marketplace and trading operations, including creating and fulfilling listings and offers, canceling orders, retrieving swap quotes, and building drop mint transactions, as well as analytics and event endpoints for collection stats and activity streams filtered by collection, NFT, or account.

Access requires an API key sent via the x-api-key header, obtainable instantly through the API or via the developer portal; certain wallet-specific endpoints additionally require a scoped bearer token. The API is rate-limited, with higher throughput available on request for production use. It is intended for developers building applications on top of the OpenSea ecosystem, and is accompanied by a TypeScript SDK (@opensea/sdk), a WebSocket-based event streaming library (@opensea/stream-js), a command-line interface (@opensea/cli), and an MCP server for AI agent integration. The API also offers a TOON-encoded response format for AI agents and LLMs, reducing token usage compared to standard JSON responses.

Key features

• Look up NFTs, collections, accounts, contracts, and tokens across supported blockchains
• Create, fulfill, and cancel marketplace listings and offers
• Get swap quotes and execute token swaps
• Build mint transactions for drops
• Query collection stats and real-time event streams (sales, transfers, listings, offers)
• TOON-encoded responses for AI agents to reduce token usage

Frequently asked questions