How to integrate Open sea MCP with OpenAI Agents SDK

This guide walks you through connecting Open sea to the OpenAI Agents SDK using the Composio tool router. By the end, you'll have a working Open sea agent that can list your nft for sale on opensea, show all active listings in bored ape collection, create an offer for a specific cryptopunk through natural language commands. This guide will help you understand how to give your OpenAI Agents SDK agent real control over a Open sea account through Composio's Open sea MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

Open sea logoOpen sea
Api Key

OpenSea is the world's first and largest NFT marketplace for digital collectibles and crypto assets. Instantly buy, sell, and explore NFTs across blockchains, all in one place.

24 Tools

Introduction

This guide walks you through connecting Open sea to the OpenAI Agents SDK using the Composio tool router. By the end, you'll have a working Open sea agent that can list your nft for sale on opensea, show all active listings in bored ape collection, create an offer for a specific cryptopunk through natural language commands.

This guide will help you understand how to give your OpenAI Agents SDK agent real control over a Open sea account through Composio's Open sea MCP server.

Before we dive in, let's take a quick look at the key ideas and tools involved.

Also integrate Open sea with

TL;DR

Here's what you'll learn:
  • Get and set up your OpenAI and Composio API keys
  • Install the necessary dependencies
  • Initialize Composio and create a Tool Router session for Open sea
  • Configure an AI agent that can use Open sea as a tool
  • Run a live chat session where you can ask the agent to perform Open sea operations

What is OpenAI Agents SDK?

The OpenAI Agents SDK is a lightweight framework for building AI agents that can use tools and maintain conversation state. It provides a simple interface for creating agents with hosted MCP tool support.

Key features include:

  • Hosted MCP Tools: Connect to external services through hosted MCP endpoints
  • SQLite Sessions: Persist conversation history across interactions
  • Simple API: Clean interface with Agent, Runner, and tool configuration
  • Streaming Support: Real-time response streaming for interactive applications

What is the Open sea MCP server, and what's possible with it?

The Open sea MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your OpenSea account. It provides structured and secure access to your NFT marketplace activity, so your agent can perform actions like listing NFTs for sale, creating and fulfilling offers, checking account details, and managing your marketplace orders on your behalf.

  • NFT listing automation: Quickly list any ERC721 or ERC1155 NFT for sale on OpenSea, specifying price and collection details—all handled by your agent.
  • Offer creation and management: Instruct your agent to create criteria-based or single-item offers to purchase specific NFTs or those matching certain traits within a collection.
  • Order and listing fulfillment: Let your agent retrieve all necessary information and signatures to fulfill existing listings or offers, making transactions seamless and secure.
  • Marketplace activity insights: Have the agent pull your profile details, fetch all active listings or offers for a given collection, and provide you with up-to-date marketplace snapshots.
  • Order cancellation and management: Direct your agent to cancel open orders, listings, or offers off-chain, helping you stay in control of your marketplace participation with ease.

What is the Composio tool router, and how does it fit here?

What is Composio SDK?

Composio's Composio SDK helps agents find the right tools for a task at runtime. You can plug in multiple toolkits (like Gmail, HubSpot, and GitHub), and the agent will identify the relevant app and action to complete multi-step workflows. This can reduce token usage and improve the reliability of tool calls. Read more here: Getting started with Composio SDK

The tool router generates a secure MCP URL that your agents can access to perform actions.

How the Composio SDK works

The Composio SDK follows a three-phase workflow:

  1. Discovery: Searches for tools matching your task and returns relevant toolkits with their details.
  2. Authentication: Checks for active connections. If missing, creates an auth config and returns a connection URL via Auth Link.
  3. Execution: Executes the action using the authenticated connection.

Step-by-step Guide

Step by step09 STEPS
1

Prerequisites

Before starting, make sure you have:
  • Composio API Key and OpenAI API Key
  • Primary know-how of OpenAI Agents SDK
  • A live Open sea project
  • Some knowledge of Python or Typescript
2

Getting API Keys for OpenAI and Composio

OpenAI API Key
  • Go to the OpenAI dashboard and create an API key. You'll need credits to use the models, or you can connect to another model provider.
  • Keep the API key safe.
Composio API Key
3

Install dependencies

npm install @composio/openai-agents @openai/agents dotenv

Install the Composio SDK and the OpenAI Agents SDK.

4

Set up environment variables

bash
OPENAI_API_KEY=sk-...your-api-key
COMPOSIO_API_KEY=your-api-key
USER_ID=composio_user@gmail.com

Create a .env file and add your OpenAI and Composio API keys.

5

Import dependencies

import 'dotenv/config';
import { Composio } from '@composio/core';
import { OpenAIAgentsProvider } from '@composio/openai-agents';
import { Agent, hostedMcpTool, run, OpenAIConversationsSession } from '@openai/agents';
import * as readline from 'readline';
What's happening:
  • You're importing all necessary libraries.
  • The Composio and OpenAIAgentsProvider classes are imported to connect your OpenAI agent to Composio tools like Open sea.
6

Set up the Composio instance

dotenv.config();

const composioApiKey = process.env.COMPOSIO_API_KEY;
const userId = process.env.USER_ID;

if (!composioApiKey) {
  throw new Error('COMPOSIO_API_KEY is not set. Create a .env file with COMPOSIO_API_KEY=your_key');
}
if (!userId) {
  throw new Error('USER_ID is not set');
}

// Initialize Composio
const composio = new Composio({
  apiKey: composioApiKey,
  provider: new OpenAIAgentsProvider(),
});
What's happening:
  • dotenv.config() loads your .env file so COMPOSIO_API_KEY and USER_ID are available as environment variables.
  • Creating a Composio instance using the API Key and OpenAIAgentsProvider class.
7

Create a Tool Router session

// Create Tool Router session for Open sea
const session = await composio.create(userId as string, {
  toolkits: ['open_sea'],
});
const mcpUrl = session.mcp.url;

What is happening:

  • You give the Tool Router the user id and the toolkits you want available. Here, it is only open_sea.
  • The router checks the user's Open sea connection and prepares the MCP endpoint.
  • The returned session.mcp.url is the MCP URL that your agent will use to access Open sea.
  • This approach keeps things lightweight and lets the agent request Open sea tools only when needed during the conversation.
8

Configure the agent

// Configure agent with MCP tool
const agent = new Agent({
  name: 'Assistant',
  model: 'gpt-5',
  instructions:
    'You are a helpful assistant that can access Open sea. Help users perform Open sea operations through natural language.',
  tools: [
    hostedMcpTool({
      serverLabel: 'tool_router',
      serverUrl: mcpUrl,
      headers: { 'x-api-key': composioApiKey },
      requireApproval: 'never',
    }),
  ],
});
What's happening:
  • We're creating an Agent instance with a name, model (gpt-5), and clear instructions about its purpose.
  • The agent's instructions tell it that it can access Open sea and help with queries, inserts, updates, authentication, and fetching database information.
  • The tools array includes a hostedMcpTool that connects to the MCP server URL we created earlier.
  • The headers object includes the Composio API key for secure authentication with the MCP server.
  • requireApproval: 'never' means the agent can execute Open sea operations without asking for permission each time, making interactions smoother.
9

Start chat loop and handle conversation

// Keep conversation state across turns
const conversationSession = new OpenAIConversationsSession();

// Simple CLI
const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout,
  prompt: 'You: ',
});

console.log('\nComposio Tool Router session created.');
console.log('\nChat started. Type your requests below.');
console.log("Commands: 'exit', 'quit', or 'q' to end\n");

try {
  const first = await run(agent, 'What can you help me with?', { session: conversationSession });
  console.log(`Assistant: ${first.finalOutput}\n`);
} catch (e) {
  console.error('Error:', e instanceof Error ? e.message : e, '\n');
}

rl.prompt();

rl.on('line', async (userInput) => {
  const text = userInput.trim();

  if (['exit', 'quit', 'q'].includes(text.toLowerCase())) {
    console.log('Goodbye!');
    rl.close();
    process.exit(0);
  }

  if (!text) {
    rl.prompt();
    return;
  }

  try {
    const result = await run(agent, text, { session: conversationSession });
    console.log(`\nAssistant: ${result.finalOutput}\n`);
  } catch (e) {
    console.error('Error:', e instanceof Error ? e.message : e, '\n');
  }

  rl.prompt();
});

rl.on('close', () => {
  console.log('\n👋 Session ended.');
  process.exit(0);
});
What's happening:
  • The program prints a session URL that you visit to authorize Open sea.
  • After authorization, the chat begins.
  • Each message you type is processed by the agent using run().
  • The responses are printed to the console.
  • Typing exit, quit, or q cleanly ends the chat.

Complete Code

Here's the complete code to get you started with Open sea and OpenAI Agents SDK:

import 'dotenv/config';
import { Composio } from '@composio/core';
import { OpenAIAgentsProvider } from '@composio/openai-agents';
import { Agent, hostedMcpTool, run, OpenAIConversationsSession } from '@openai/agents';
import * as readline from 'readline';

const composioApiKey = process.env.COMPOSIO_API_KEY;
const userId = process.env.USER_ID;

if (!composioApiKey) {
  throw new Error('COMPOSIO_API_KEY is not set. Create a .env file with COMPOSIO_API_KEY=your_key');
}
if (!userId) {
  throw new Error('USER_ID is not set');
}

// Initialize Composio
const composio = new Composio({
  apiKey: composioApiKey,
  provider: new OpenAIAgentsProvider(),
});

async function main() {
  // Create Tool Router session
  const session = await composio.create(userId as string, {
    toolkits: ['open_sea'],
  });
  const mcpUrl = session.mcp.url;

  // Configure agent with MCP tool
  const agent = new Agent({
    name: 'Assistant',
    model: 'gpt-5',
    instructions:
      'You are a helpful assistant that can access Open sea. Help users perform Open sea operations through natural language.',
    tools: [
      hostedMcpTool({
        serverLabel: 'tool_router',
        serverUrl: mcpUrl,
        headers: { 'x-api-key': composioApiKey },
        requireApproval: 'never',
      }),
    ],
  });

  // Keep conversation state across turns
  const conversationSession = new OpenAIConversationsSession();

  // Simple CLI
  const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
    prompt: 'You: ',
  });

  console.log('\nComposio Tool Router session created.');
  console.log('\nChat started. Type your requests below.');
  console.log("Commands: 'exit', 'quit', or 'q' to end\n");

  try {
    const first = await run(agent, 'What can you help me with?', { session: conversationSession });
    console.log(`Assistant: ${first.finalOutput}\n`);
  } catch (e) {
    console.error('Error:', e instanceof Error ? e.message : e, '\n');
  }

  rl.prompt();

  rl.on('line', async (userInput) => {
    const text = userInput.trim();

    if (['exit', 'quit', 'q'].includes(text.toLowerCase())) {
      console.log('Goodbye!');
      rl.close();
      process.exit(0);
    }

    if (!text) {
      rl.prompt();
      return;
    }

    try {
      const result = await run(agent, text, { session: conversationSession });
      console.log(`\nAssistant: ${result.finalOutput}\n`);
    } catch (e) {
      console.error('Error:', e instanceof Error ? e.message : e, '\n');
    }

    rl.prompt();
  });

  rl.on('close', () => {
    console.log('\nSession ended.');
    process.exit(0);
  });
}

main().catch((err) => {
  console.error('Fatal error:', err);
  process.exit(1);
});

Conclusion

This was a starter code for integrating Open sea MCP with OpenAI Agents SDK to build a functional AI agent that can interact with Open sea.

Key features:

  • Hosted MCP tool integration through Composio's Tool Router
  • SQLite session persistence for conversation history
  • Simple async chat loop for interactive testing
You can extend this by adding more toolkits, implementing custom business logic, or building a web interface around the agent.
TOOLS

Supported Tools

Every Open sea action and event your agent gets out of the box.

Build criteria offer

Build a portion of a criteria offer including the merkle tree needed to post an offer.

Cancel order

Offchain cancel a single order, offer or listing, by its order hash when protected by the SignedZone.

Create criteria offer

Create a criteria offer to purchase any NFT in a collection or which matches the specified trait.

Create item offer

Create an offer to purchase a single NFT (ERC721 or ERC1155).

Create listing

List a single NFT (ERC721 or ERC1155) for sale on the OpenSea marketplace.

Fulfill listing

Retrieve all the information, including signatures, needed to fulfill a listing directly onchain.

Fulfill offer

Retrieve all the information, including signatures, needed to fulfill an offer directly onchain.

Get account

Get an OpenSea Account Profile including details such as bio, social media usernames, and profile image.

Get all listings by collection

Get all active, valid listings for a single collection.

Get all offers by collection

Get all active, valid offers for the specified collection.

Get best listing by nft

Get the best listing for an NFT.

Get best listings by collection

Get the cheapest priced active, valid listings on a single collection.

Get best offer by nft

Get the best offers for an NFT.

Get collection

Get a single collection including details such as fees, traits, and links.

Get collections

Get a list of OpenSea collections with optional filtering and pagination.

Get collection stats

Get stats for a single collection on OpenSea.

Get contract

Get a smart contract for a given chain and address.

Get events

Get a list of events from OpenSea based on various filters like timestamps and event types.

Get listings

Get the complete set of active, valid listings.

Get nft

Get metadata, traits, ownership information, and rarity for a single NFT.

Get order

Get a single order, offer or listing, by its order hash.

Get payment token

Get a smart contract for a given chain and address.

Get traits

Get the traits in a collection.

Refresh nft metadata

Refresh metadata for a single NFT.

FAQ

Frequently asked questions

With a standalone Open sea MCP server, the agents and LLMs can only access a fixed set of Open sea tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Open sea and many other apps based on the task at hand, all through a single MCP endpoint.

Yes, you can. OpenAI Agents SDK fully supports MCP integration. You get structured tool calling, message history handling, and model orchestration while Tool Router takes care of discovering and serving the right Open sea tools.

Yes, absolutely. You can configure which Open sea scopes and actions are allowed when connecting your account to Composio. You can also bring your own OAuth credentials or API configuration so you keep full control over what the agent can do.

All sensitive data such as tokens, keys, and configuration is fully encrypted at rest and in transit. Composio is SOC 2 Type 2 compliant and follows strict security practices so your Open sea data and credentials are handled as safely as possible.

Start with Open sea.It takes 30 seconds.

Managed auth, hosted MCP servers, and every Open sea tool your agent needs.Free to start.

Start building