The OpenSea API gives you access to NFTs, tokens, and marketplace data across supported blockchains. Use it to fetch metadata, create and fulfill orders, track events, and build on top of the OpenSea ecosystem.

What you can do

Data & Discovery — Look up accounts, collections, NFTs, contracts, and tokens. Search across the OpenSea ecosystem.

Marketplace & Trading — Create and fulfill listings and offers, cancel orders, get swap quotes, and build drop mint transactions.

Analytics & Events — Query collection stats (floor price, volume, sales) and event streams (sales, transfers, listings, offers) filtered by collection, NFT, or account.

Quick start

Get an API key — either instantly via API or through the developer portal:

# Get an instant free-tier key (no signup needed)
curl -X POST https://api.opensea.io/api/v2/auth/keys

Make your first request:

curl "https://api.opensea.io/api/v2/collections/doodles-official" \
  -H "x-api-key: YOUR_API_KEY"

Explore the endpoints in the sidebar

Authentication

All requests require an API key passed via the x-api-key header. You can get one instantly via API or through the developer portal. See Getting Your API Key for details.

Token-optimized responses for AI agents

AI agents and LLMs can request TOON-encoded responses (Token-Optimized Object Notation) by sending an Accept: text/markdown header. TOON is a compact, lossless text format that uses ~40% fewer tokens than JSON — ideal for agents operating under context limits.

curl "https://api.opensea.io/api/v2/collections/doodles-official" \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Accept: text/markdown"

JSON remains the default for all requests without this header. See LLMs & Agent Discovery for more details.

Rate limits

The API is rate-limited. If you need higher throughput for a production application, reach out to discuss your use case.

Attribution

When using OpenSea data, please link back to the OpenSea marketplace from the NFTs you display and provide attribution using our Logos & Brand Guidelines.

SDKs & tools

@opensea/sdk — TypeScript SDK for marketplace actions
@opensea/stream-js — Real-time event streaming via WebSocket
@opensea/cli — Command-line interface for the OpenSea API
MCP Server — Model Context Protocol integration for AI agents

Get help