---
updatedAt: 2026-09-24T05:30:09.000Z
agentTools:
  projectIndex: https://docs.opensea.io/llms.txt
---

# Overview

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 and discovery**: Look up accounts, collections, NFTs, contracts, and tokens. Search across the OpenSea ecosystem.

**Marketplace and trading**: Create and fulfill listings and offers, cancel orders, get swap quotes, and build drop mint transactions.

**Analytics and events**: Query collection stats (floor price, volume, sales) and event streams (sales, transfers, listings, offers) filtered by collection, NFT, or account.

## Quick start

1. Get an API key, either [instantly via API](https://docs.opensea.io/reference/api-keys#instant-api-key-for-agents) or through the [developer portal](https://docs.opensea.io/reference/api-keys#how-do-i-get-an-api-key):
   ```bash
   # Get an instant free-tier key (no signup needed)
   curl -X POST https://api.opensea.io/api/v2/auth/keys
   ```
2. Make your first request:
   ```bash
   curl "https://api.opensea.io/api/v2/collections/doodles-official" \
     -H "x-api-key: YOUR_API_KEY"
   ```
3. 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](https://docs.opensea.io/reference/api-keys#instant-api-key-for-agents) or through the [developer portal](https://docs.opensea.io/reference/api-keys#how-do-i-get-an-api-key). See [API keys](https://docs.opensea.io/reference/api-keys) for details.

Wallet-specific endpoints (drop eligibility, favorites, order cancellation) also require a scoped token via the `Authorization: Bearer <token>` header. See [Authentication](https://docs.opensea.io/reference/auth) for the full guide on obtaining and using scoped tokens.

## 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, which helps agents operating under context limits.

```bash
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 and agent discovery](https://docs.opensea.io/reference/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 [logo assets](https://docs.opensea.io/docs/logos).

## SDKs & tools

* [TypeScript SDK](https://docs.opensea.io/reference/opensea-sdk): marketplace actions with `@opensea/sdk`
* [Stream API](https://docs.opensea.io/reference/stream-api): Real-time event streaming via WebSocket, via `@opensea/sdk/stream`
* [CLI](https://docs.opensea.io/reference/opensea-cli): command-line access to the OpenSea API with `@opensea/cli`
* [MCP server](https://docs.opensea.io/reference/mcp): Model Context Protocol integration for AI agents

## Get help

* [Developer Discord](https://discord.com/channels/397566282729390110/434175585745633280)
* <api@opensea.io>