OpenSea Skill

Query NFT data, trade on the Seaport marketplace, and swap ERC20 tokens across Ethereum, Base, Arbitrum, Optimism, Polygon, and more.

What is this?

This is an Agent Skill for AI coding assistants. Once installed, your agent can interact with the OpenSea API to query NFT data, execute marketplace operations, and swap ERC20 tokens using the OpenSea CLI, shell scripts, or the MCP server.

Prerequisites

• OPENSEA_API_KEY environment variable — for CLI, SDK, and REST API scripts
• OPENSEA_MCP_TOKEN environment variable — for the MCP server (separate from API key)
• Node.js >= 18.0.0 — for @opensea/cli
• curl for REST shell scripts
• jq (recommended) for parsing JSON responses

Get both credentials at opensea.io/settings/developer.

Installing the Skill

Using npx

npx skills add ProjectOpenSea/opensea-skill

Using Claude Code

/skill install ProjectOpenSea/opensea-skill

Manual Installation

Clone this repository to your skills directory:

git clone https://github.com/ProjectOpenSea/opensea-skill.git ~/.skills/opensea

Refer to your AI tool's documentation for skills directory configuration.

What's Included

Skill Definition

SKILL.md — the main skill file that teaches your agent how to use the OpenSea API, including the CLI, task guides, script references, MCP tool documentation, and end-to-end workflows for buying, selling, and swapping tokens.

OpenSea CLI (Recommended)

The @opensea/cli package provides a command-line interface and programmatic SDK for all OpenSea API operations. Install with npm install -g @opensea/cli or use npx @opensea/cli.

opensea collections get mfers
opensea listings best mfers --limit 5
opensea tokens trending --limit 5
opensea search "cool cats"
opensea swaps quote --from-chain base --from-address 0x0000000000000000000000000000000000000000 \
  --to-chain base --to-address 0xTokenAddress --quantity 0.02 --address 0xYourWallet

Supports JSON, table, and TOON output formats. TOON uses ~40% fewer tokens than JSON, ideal for AI agent context windows (--format toon).

See SKILL.md for the full CLI command reference and SDK usage.

Shell Scripts

Ready-to-use scripts in scripts/ for common operations (alternative to the CLI):

Script	Purpose
opensea-collection.sh	Fetch collection by slug
opensea-nft.sh	Fetch single NFT by chain/contract/token
opensea-best-listing.sh	Get lowest listing for an NFT
opensea-best-offer.sh	Get highest offer for an NFT
opensea-swap.sh	Swap tokens via OpenSea DEX aggregator
opensea-fulfill-listing.sh	Get buy transaction data
opensea-fulfill-offer.sh	Get sell transaction data

See SKILL.md for the full scripts reference and usage examples.

Reference Docs

Detailed API documentation in references/:

• rest-api.md — REST endpoint families and pagination
• marketplace-api.md — Buy/sell workflows and Seaport details
• stream-api.md — WebSocket event streaming
• seaport.md — Seaport protocol and NFT purchase execution
• token-swaps.md — Token swap workflows via MCP

OpenSea MCP Server

An official MCP server provides direct LLM integration for token swaps and NFT operations. Add to your MCP config:

{
  "mcpServers": {
    "opensea": {
      "url": "https://mcp.opensea.io/mcp",
      "headers": {
        "Authorization": "Bearer YOUR_MCP_TOKEN"
      }
    }
  }
}

See SKILL.md for the full list of available MCP tools.

Example Usage

Once installed, prompt your AI assistant:

Get me the floor price for the Pudgy Penguins collection on OpenSea

Swap 0.02 ETH to USDC on Base using OpenSea

Show me the best offer on BAYC #1234

The agent will use the opensea CLI to query the API directly.

Supported Chains

This skill supports all chains available on OpenSea, including ethereum, solana, abstract, ape_chain, arbitrum, avalanche, b3, base, bera_chain, blast, flow, gunzilla, hyperevm, hyperliquid, ink, megaeth, monad, optimism, polygon, ronin, sei, shape, somnia, soneium, unichain, and zora.

Learn More

• OpenSea CLI — CLI and SDK for OpenSea API
• OpenSea Developer Docs
• OpenSea Developer Portal
• Agent Skills Directory