# How to integrate Open sea MCP with Pydantic AI ```json { "title": "How to integrate Open sea MCP with Pydantic AI", "toolkit": "Open sea", "toolkit_slug": "open_sea", "framework": "Pydantic AI", "framework_slug": "pydantic-ai", "url": "https://composio.dev/toolkits/open_sea/framework/pydantic-ai", "markdown_url": "https://composio.dev/toolkits/open_sea/framework/pydantic-ai.md", "updated_at": "2026-05-12T10:20:45.461Z" } ``` ## Introduction This guide walks you through connecting Open sea to Pydantic AI 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 Pydantic AI 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 - [OpenAI Agents SDK](https://composio.dev/toolkits/open_sea/framework/open-ai-agents-sdk) - [Claude Agent SDK](https://composio.dev/toolkits/open_sea/framework/claude-agents-sdk) - [Claude Code](https://composio.dev/toolkits/open_sea/framework/claude-code) - [Claude Cowork](https://composio.dev/toolkits/open_sea/framework/claude-cowork) - [Codex](https://composio.dev/toolkits/open_sea/framework/codex) - [OpenClaw](https://composio.dev/toolkits/open_sea/framework/openclaw) - [Hermes](https://composio.dev/toolkits/open_sea/framework/hermes-agent) - [CLI](https://composio.dev/toolkits/open_sea/framework/cli) - [Google ADK](https://composio.dev/toolkits/open_sea/framework/google-adk) - [LangChain](https://composio.dev/toolkits/open_sea/framework/langchain) - [Vercel AI SDK](https://composio.dev/toolkits/open_sea/framework/ai-sdk) - [Mastra AI](https://composio.dev/toolkits/open_sea/framework/mastra-ai) - [LlamaIndex](https://composio.dev/toolkits/open_sea/framework/llama-index) - [CrewAI](https://composio.dev/toolkits/open_sea/framework/crew-ai) ## TL;DR Here's what you'll learn: - How to set up your Composio API key and User ID - How to create a Composio Tool Router session for Open sea - How to attach an MCP Server to a Pydantic AI agent - How to stream responses and maintain chat history - How to build a simple REPL-style chat interface to test your Open sea workflows ## What is Pydantic AI? Pydantic AI is a Python framework for building AI agents with strong typing and validation. It leverages Pydantic's data validation capabilities to create robust, type-safe AI applications. Key features include: - Type Safety: Built on Pydantic for automatic data validation - MCP Support: Native support for Model Context Protocol servers - Streaming: Built-in support for streaming responses - Async First: Designed for async/await patterns ## 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. ## Supported Tools | Tool slug | Name | Description | |---|---|---| | `OPEN_SEA_BUILD_CRITERIA_OFFER` | Build criteria offer | Build a portion of a criteria offer including the merkle tree needed to post an offer. | | `OPEN_SEA_CANCEL_ORDER` | Cancel order | Offchain cancel a single order, offer or listing, by its order hash when protected by the SignedZone. Protocol and Chain are required to prevent hash collisions. Please note cancellation is only assured if a fulfillment signature was not vended prior to cancellation. | | `OPEN_SEA_CREATE_CRITERIA_OFFER` | Create criteria offer | Create a criteria offer to purchase any NFT in a collection or which matches the specified trait. | | `OPEN_SEA_CREATE_ITEM_OFFER` | Create item offer | Create an offer to purchase a single NFT (ERC721 or ERC1155). | | `OPEN_SEA_CREATE_LISTING` | Create listing | List a single NFT (ERC721 or ERC1155) for sale on the OpenSea marketplace. | | `OPEN_SEA_FULFILL_LISTING` | Fulfill listing | Retrieve all the information, including signatures, needed to fulfill a listing directly onchain. | | `OPEN_SEA_FULFILL_OFFER` | Fulfill offer | Retrieve all the information, including signatures, needed to fulfill an offer directly onchain. | | `OPEN_SEA_GET_ACCOUNT` | Get account | Get an OpenSea Account Profile including details such as bio, social media usernames, and profile image. | | `OPEN_SEA_GET_ALL_LISTINGS_BY_COLLECTION` | Get all listings by collection | Get all active, valid listings for a single collection. | | `OPEN_SEA_GET_ALL_OFFERS_BY_COLLECTION` | Get all offers by collection | Get all active, valid offers for the specified collection. This includes individual and criteria offers. | | `OPEN_SEA_GET_BEST_LISTING_BY_NFT` | Get best listing by nft | Get the best listing for an NFT. | | `OPEN_SEA_GET_BEST_LISTINGS_BY_COLLECTION` | Get best listings by collection | Get the cheapest priced active, valid listings on a single collection. | | `OPEN_SEA_GET_BEST_OFFER_BY_NFT` | Get best offer by nft | Get the best offers for an NFT. | | `OPEN_SEA_GET_COLLECTION` | Get collection | Get a single collection including details such as fees, traits, and links. | | `OPEN_SEA_GET_COLLECTIONS` | Get collections | Get a list of OpenSea collections with optional filtering and pagination. | | `OPEN_SEA_GET_COLLECTION_STATS` | Get collection stats | Get stats for a single collection on OpenSea. | | `OPEN_SEA_GET_CONTRACT` | Get contract | Get a smart contract for a given chain and address. | | `OPEN_SEA_GET_EVENTS` | Get events | Get a list of events from OpenSea based on various filters like timestamps and event types. | | `OPEN_SEA_GET_LISTINGS` | Get listings | Get the complete set of active, valid listings. | | `OPEN_SEA_GET_NFT` | Get nft | Get metadata, traits, ownership information, and rarity for a single NFT. | | `OPEN_SEA_GET_ORDER` | Get order | Get a single order, offer or listing, by its order hash. Protocol and Chain are required to prevent hash collisions. | | `OPEN_SEA_GET_PAYMENT_TOKEN` | Get payment token | Get a smart contract for a given chain and address. | | `OPEN_SEA_GET_TRAITS` | Get traits | Get the traits in a collection. | | `OPEN_SEA_REFRESH_NFT_METADATA` | Refresh nft metadata | Refresh metadata for a single NFT. | ## Supported Triggers None listed. ## Creating MCP Server - Stand-alone vs Composio SDK The Open sea MCP server is an implementation of the Model Context Protocol that connects your AI agent to Open sea. It provides structured and secure access so your agent can perform Open sea operations on your behalf through a secure, permission-based interface. With Composio's managed implementation, you don't have to create your own developer app. For production, if you're building an end product, we recommend using your own credentials. The managed server helps you prototype fast and go from 0-1 faster. ## Step-by-step Guide ### 1. Prerequisites Before starting, make sure you have: - Python 3.9 or higher - A Composio account with an active API key - Basic familiarity with Python and async programming ### 1. Getting API Keys for OpenAI and Composio OpenAI API Key - Go to the [OpenAI dashboard](https://platform.openai.com/settings/organization/api-keys) 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 - Log in to the [Composio dashboard](https://dashboard.composio.dev?utm_source=toolkits&utm_medium=framework_docs). - Navigate to your API settings and generate a new API key. - Store this key securely as you'll need it for authentication. ### 2. Install dependencies Install the required libraries. What's happening: - composio connects your agent to external SaaS tools like Open sea - pydantic-ai lets you create structured AI agents with tool support - python-dotenv loads your environment variables securely from a .env file ```bash pip install composio pydantic-ai python-dotenv ``` ### 3. Set up environment variables Create a .env file in your project root. What's happening: - COMPOSIO_API_KEY authenticates your agent to Composio's API - USER_ID associates your session with your account for secure tool access - OPENAI_API_KEY to access OpenAI LLMs ```bash COMPOSIO_API_KEY=your_composio_api_key_here USER_ID=your_user_id_here OPENAI_API_KEY=your_openai_api_key ``` ### 4. Import dependencies What's happening: - We load environment variables and import required modules - Composio manages connections to Open sea - MCPServerStreamableHTTP connects to the Open sea MCP server endpoint - Agent from Pydantic AI lets you define and run the AI assistant ```python import asyncio import os from dotenv import load_dotenv from composio import Composio from pydantic_ai import Agent from pydantic_ai.mcp import MCPServerStreamableHTTP load_dotenv() ``` ### 5. Create a Tool Router Session What's happening: - We're creating a Tool Router session that gives your agent access to Open sea tools - The create method takes the user ID and specifies which toolkits should be available - The returned session.mcp.url is the MCP server URL that your agent will use ```python async def main(): api_key = os.getenv("COMPOSIO_API_KEY") user_id = os.getenv("USER_ID") if not api_key or not user_id: raise RuntimeError("Set COMPOSIO_API_KEY and USER_ID in your environment") # Create a Composio Tool Router session for Open sea composio = Composio(api_key=api_key) session = composio.create( user_id=user_id, toolkits=["open_sea"], ) url = session.mcp.url if not url: raise ValueError("Composio session did not return an MCP URL") ``` ### 6. Initialize the Pydantic AI Agent What's happening: - The MCP client connects to the Open sea endpoint - The agent uses GPT-5 to interpret user commands and perform Open sea operations - The instructions field defines the agent's role and behavior ```python # Attach the MCP server to a Pydantic AI Agent open_sea_mcp = MCPServerStreamableHTTP(url, headers={"x-api-key": COMPOSIO_API_KEY}) agent = Agent( "openai:gpt-5", toolsets=[open_sea_mcp], instructions=( "You are a Open sea assistant. Use Open sea tools to help users " "with their requests. Ask clarifying questions when needed." ), ) ``` ### 7. Build the chat interface What's happening: - The agent reads input from the terminal and streams its response - Open sea API calls happen automatically under the hood - The model keeps conversation history to maintain context across turns ```python # Simple REPL with message history history = [] print("Chat started! Type 'exit' or 'quit' to end.\n") print("Try asking the agent to help you with Open sea.\n") while True: user_input = input("You: ").strip() if user_input.lower() in {"exit", "quit", "bye"}: print("\nGoodbye!") break if not user_input: continue print("\nAgent is thinking...\n", flush=True) async with agent.run_stream(user_input, message_history=history) as stream_result: collected_text = "" async for chunk in stream_result.stream_output(): text_piece = None if isinstance(chunk, str): text_piece = chunk elif hasattr(chunk, "delta") and isinstance(chunk.delta, str): text_piece = chunk.delta elif hasattr(chunk, "text"): text_piece = chunk.text if text_piece: collected_text += text_piece result = stream_result print(f"Agent: {collected_text}\n") history = result.all_messages() ``` ### 8. Run the application What's happening: - The asyncio loop launches the agent and keeps it running until you exit ```python if __name__ == "__main__": asyncio.run(main()) ``` ## Complete Code ```python import asyncio import os from dotenv import load_dotenv from composio import Composio from pydantic_ai import Agent from pydantic_ai.mcp import MCPServerStreamableHTTP load_dotenv() async def main(): api_key = os.getenv("COMPOSIO_API_KEY") user_id = os.getenv("USER_ID") if not api_key or not user_id: raise RuntimeError("Set COMPOSIO_API_KEY and USER_ID in your environment") # Create a Composio Tool Router session for Open sea composio = Composio(api_key=api_key) session = composio.create( user_id=user_id, toolkits=["open_sea"], ) url = session.mcp.url if not url: raise ValueError("Composio session did not return an MCP URL") # Attach the MCP server to a Pydantic AI Agent open_sea_mcp = MCPServerStreamableHTTP(url, headers={"x-api-key": COMPOSIO_API_KEY}) agent = Agent( "openai:gpt-5", toolsets=[open_sea_mcp], instructions=( "You are a Open sea assistant. Use Open sea tools to help users " "with their requests. Ask clarifying questions when needed." ), ) # Simple REPL with message history history = [] print("Chat started! Type 'exit' or 'quit' to end.\n") print("Try asking the agent to help you with Open sea.\n") while True: user_input = input("You: ").strip() if user_input.lower() in {"exit", "quit", "bye"}: print("\nGoodbye!") break if not user_input: continue print("\nAgent is thinking...\n", flush=True) async with agent.run_stream(user_input, message_history=history) as stream_result: collected_text = "" async for chunk in stream_result.stream_output(): text_piece = None if isinstance(chunk, str): text_piece = chunk elif hasattr(chunk, "delta") and isinstance(chunk.delta, str): text_piece = chunk.delta elif hasattr(chunk, "text"): text_piece = chunk.text if text_piece: collected_text += text_piece result = stream_result print(f"Agent: {collected_text}\n") history = result.all_messages() if __name__ == "__main__": asyncio.run(main()) ``` ## Conclusion You've built a Pydantic AI agent that can interact with Open sea through Composio's Tool Router. With this setup, your agent can perform real Open sea actions through natural language. You can extend this further by: - Adding other toolkits like Gmail, HubSpot, or Salesforce - Building a web-based chat interface around this agent - Using multiple MCP endpoints to enable cross-app workflows (for example, Gmail + Open sea for workflow automation) This architecture makes your AI agent "agent-native", able to securely use APIs in a unified, composable way without custom integrations. ## How to build Open sea MCP Agent with another framework - [OpenAI Agents SDK](https://composio.dev/toolkits/open_sea/framework/open-ai-agents-sdk) - [Claude Agent SDK](https://composio.dev/toolkits/open_sea/framework/claude-agents-sdk) - [Claude Code](https://composio.dev/toolkits/open_sea/framework/claude-code) - [Claude Cowork](https://composio.dev/toolkits/open_sea/framework/claude-cowork) - [Codex](https://composio.dev/toolkits/open_sea/framework/codex) - [OpenClaw](https://composio.dev/toolkits/open_sea/framework/openclaw) - [Hermes](https://composio.dev/toolkits/open_sea/framework/hermes-agent) - [CLI](https://composio.dev/toolkits/open_sea/framework/cli) - [Google ADK](https://composio.dev/toolkits/open_sea/framework/google-adk) - [LangChain](https://composio.dev/toolkits/open_sea/framework/langchain) - [Vercel AI SDK](https://composio.dev/toolkits/open_sea/framework/ai-sdk) - [Mastra AI](https://composio.dev/toolkits/open_sea/framework/mastra-ai) - [LlamaIndex](https://composio.dev/toolkits/open_sea/framework/llama-index) - [CrewAI](https://composio.dev/toolkits/open_sea/framework/crew-ai) ## Related Toolkits - [Addresszen](https://composio.dev/toolkits/addresszen) - Addresszen is a real-time address autocomplete and verification service. It helps capture accurate, deliverable addresses with instant suggestions and validation. - [Asin data api](https://composio.dev/toolkits/asin_data_api) - Asin data api gives you detailed, real-time product data from Amazon, including price, rank, and reviews. Perfect for e-commerce pros and data-driven marketers who need instant marketplace insights. - [Baselinker](https://composio.dev/toolkits/baselinker) - BaseLinker is an all-in-one e-commerce management platform connecting stores, marketplaces, carriers, and more. It streamlines order processing, inventory control, and automates your sales operations. - [Bestbuy](https://composio.dev/toolkits/bestbuy) - Best Buy is a leading retailer offering APIs for product, store, and recommendation data. Instantly access up-to-date retail insights for smarter shopping and decision-making. - [Btcpay server](https://composio.dev/toolkits/btcpay_server) - BTCPay Server is a free, open-source, self-hosted Bitcoin payment processor. It lets merchants accept Bitcoin payments directly, cutting out middlemen and boosting privacy. - [Cdr platform](https://composio.dev/toolkits/cdr_platform) - Cdr platform is an API for purchasing carbon dioxide removal services. It enables businesses to offset emissions by accessing verified carbon removal projects. - [Cloudcart](https://composio.dev/toolkits/cloudcart) - CloudCart is an e-commerce platform for building and managing online stores. It helps businesses streamline product listings, orders, and customer engagement. - [Countdown api](https://composio.dev/toolkits/countdown_api) - Countdown API gives you real-time, structured eBay product data, reviews, and seller feedback. Perfect for powering price monitoring, product research, or marketplace analytics workflows. - [Dpd2](https://composio.dev/toolkits/dpd2) - Dpd2 is a robust email management platform for handling, sorting, and automating email workflows. Streamline your communications and boost productivity with advanced sorting, labeling, and response tools. - [Finerworks](https://composio.dev/toolkits/finerworks) - FinerWorks is an online platform for fine art and photo printing services. Artists and photographers use it to order custom prints and manage print inventory efficiently. - [Fingertip](https://composio.dev/toolkits/fingertip) - Fingertip is a business management platform for selling, booking, and customer engagement—all from a single link. It helps businesses streamline operations and connect with customers across social channels. - [Fraudlabs pro](https://composio.dev/toolkits/fraudlabs_pro) - FraudLabs Pro is an online payment fraud detection service for e-commerce and merchants. It helps minimize chargebacks and revenue loss by detecting and preventing fraudulent transactions. - [Gift up](https://composio.dev/toolkits/gift_up) - Gift Up! is a digital platform for selling, managing, and redeeming gift cards online. It streamlines promotions and gift card transactions for businesses and their customers. - [Goody](https://composio.dev/toolkits/goody) - Goody is a gifting platform that lets users send gifts and physical products without handling logistics. It streamlines gifting by managing delivery, fulfillment, and recipient experience. - [Gumroad](https://composio.dev/toolkits/gumroad) - Gumroad is a platform for selling digital products, physical goods, and memberships with a simple checkout and marketing tools. It streamlines creator payouts and helps you grow your audience effortlessly. - [Instacart](https://composio.dev/toolkits/instacart) - Instacart is an online grocery delivery and pickup service platform. It lets you discover local retailers and create shoppable lists and recipes with ease. - [Junglescout](https://composio.dev/toolkits/junglescout) - Junglescout is an Amazon product research and analytics platform for sellers. It delivers sales estimates, competitive insights, and optimization tools to boost your Amazon business. - [Ko fi](https://composio.dev/toolkits/ko_fi) - Ko-fi is a platform that lets creators receive donations, memberships, and sales from fans. It helps creators monetize their work and grow their audience with minimal friction. - [Lemon squeezy](https://composio.dev/toolkits/lemon_squeezy) - Lemon Squeezy is a payments and subscription platform built for software companies. It makes managing payments, taxes, and customer subscriptions effortless. - [Loyverse](https://composio.dev/toolkits/loyverse) - Loyverse is a point-of-sale (POS) platform for small businesses, offering tools for sales, inventory, and customer loyalty. It helps streamline retail operations and boost customer engagement. ## Frequently Asked Questions ### What are the differences in Tool Router MCP and Open sea MCP? 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. ### Can I use Tool Router MCP with Pydantic AI? Yes, you can. Pydantic AI 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. ### Can I manage the permissions and scopes for Open sea while using Tool Router? 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. ### How safe is my data with Composio Tool Router? 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. --- [See all toolkits](https://composio.dev/toolkits) · [Composio docs](https://docs.composio.dev/llms.txt)