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How to integrate Alchemy MCP with Pydantic AI

Connect Pydantic AI to Alchemy MCP. Show all nfts owned by this wallet, get recent sales for a specific nft collection, and more using natural language, with authentication handled for you.

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Alchemy is a blockchain development platform offering APIs and tools for Ethereum apps. It simplifies building and scaling Web3 projects with robust infrastructure.

36 Tools

Introduction

This guide walks you through connecting Alchemy to Pydantic AI using the Composio tool router. By the end, you'll have a working Alchemy agent that can fetch NFTs and metadata by owner or collection, check token balances and prices, view transaction history, and detect spam contracts through natural language commands.

This guide will help you understand how to give your Pydantic AI agent real control over a Alchemy account through Composio's Alchemy MCP server.

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

Also integrate Alchemy with

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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 Alchemy
  • 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 Alchemy 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 Alchemy MCP server, and what's possible with it?

The Alchemy MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Alchemy account. It provides structured and secure access to blockchain portfolio, token, transaction, and NFT data, so your agent can inspect wallet balances, retrieve transaction history, check token prices, analyze NFTs, and identify spam contracts on your behalf.

  • Wallet and token tracking: Have your agent fetch native and fungible token holdings for wallet addresses across supported blockchain networks.
  • Token pricing and metadata: Let the agent retrieve current or historical token prices and look up details such as names, symbols, decimals, and logos.
  • Transaction history: Direct your agent to review transaction activity for wallet addresses across supported networks.
  • NFT portfolio and market research: Instruct your agent to inspect owned NFTs, collection and contract metadata, NFT sales, marketplace floor prices, and individual NFT attributes.
  • Spam contract detection: Have your agent check whether an NFT contract is marked as spam by Alchemy.

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:
  • Python 3.9 or higher
  • A Composio account with an active API key
  • Basic familiarity with Python and async programming
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
  • Log in to the Composio dashboard.
  • Navigate to your API settings and generate a new API key.
  • Store this key securely as you'll need it for authentication.
3

Install dependencies

bash
pip install composio pydantic-ai python-dotenv

Install the required libraries.

What's happening:

  • composio connects your agent to external SaaS tools like Alchemy
  • pydantic-ai lets you create structured AI agents with tool support
  • python-dotenv loads your environment variables securely from a .env file
4

Set up environment variables

bash
COMPOSIO_API_KEY=your_composio_api_key_here
USER_ID=your_user_id_here
OPENAI_API_KEY=your_openai_api_key

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
5

Import dependencies

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()
What's happening:
  • We load environment variables and import required modules
  • Composio manages connections to Alchemy
  • MCPServerStreamableHTTP connects to the Alchemy MCP server endpoint
  • Agent from Pydantic AI lets you define and run the AI assistant
6

Create a Tool Router Session

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 Alchemy
    composio = Composio(api_key=api_key)
    session = composio.create(
        user_id=user_id,
        toolkits=["alchemy"],
    )
    url = session.mcp.url
    if not url:
        raise ValueError("Composio session did not return an MCP URL")
What's happening:
  • We're creating a Tool Router session that gives your agent access to Alchemy 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
7

Initialize the Pydantic AI Agent

python
# Attach the MCP server to a Pydantic AI Agent
alchemy_mcp = MCPServerStreamableHTTP(url, headers={"x-api-key": COMPOSIO_API_KEY})
agent = Agent(
    "openai:gpt-5",
    toolsets=[alchemy_mcp],
    instructions=(
        "You are a Alchemy assistant. Use Alchemy tools to help users "
        "with their requests. Ask clarifying questions when needed."
    ),
)
What's happening:
  • The MCP client connects to the Alchemy endpoint
  • The agent uses GPT-5 to interpret user commands and perform Alchemy operations
  • The instructions field defines the agent's role and behavior
8

Build the chat interface

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 Alchemy.\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()
What's happening:
  • The agent reads input from the terminal and streams its response
  • Alchemy API calls happen automatically under the hood
  • The model keeps conversation history to maintain context across turns
9

Run the application

python
if __name__ == "__main__":
    asyncio.run(main())
What's happening:
  • The asyncio loop launches the agent and keeps it running until you exit

Complete Code

Here's the complete code to get you started with Alchemy and Pydantic AI:

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 Alchemy
    composio = Composio(api_key=api_key)
    session = composio.create(
        user_id=user_id,
        toolkits=["alchemy"],
    )
    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
    alchemy_mcp = MCPServerStreamableHTTP(url, headers={"x-api-key": COMPOSIO_API_KEY})
    agent = Agent(
        "openai:gpt-5",
        toolsets=[alchemy_mcp],
        instructions=(
            "You are a Alchemy assistant. Use Alchemy 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 Alchemy.\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 Alchemy through Composio's Tool Router. With this setup, your agent can perform real Alchemy 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 + Alchemy for workflow automation)
This architecture makes your AI agent "agent-native", able to securely use APIs in a unified, composable way without custom integrations.
TOOLS

Supported Tools

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

Compute NFT Rarity

Tool to compute the rarity of each attribute for a specific NFT based on its collection.

Get NFT Collection Metadata

Get NFT collection metadata by OpenSea slug on Ethereum mainnet, including available name, description, social links, and floor price, without requiring a contract address.

Get Collections for Owner

Tool to retrieve all NFT collections held by a specified owner address.

Get Contract Metadata Batch V3

Retrieve metadata for multiple Ethereum mainnet NFT contracts in a single batch request.

Get Contract Metadata V3

Get metadata for an Ethereum mainnet NFT contract, including available name, symbol, total supply, token type, deployer, deployment block, and OpenSea collection details.

Get Contracts for Owner (NFT API v3)

Retrieve NFT contracts from which an Ethereum mainnet wallet holds tokens, with available contract metadata, spam classification, and OpenSea metadata.

Get NFT Floor Price

Get Ethereum mainnet NFT collection floor prices from OpenSea and LooksRare, including available price, currency, collection URL, and retrieval timestamp.

Get Historical Token Prices

Retrieves historical price data for a token over a specified time range with configurable intervals.

Get NFT Contracts By Address

Tool to retrieve NFT contracts associated with one or more wallet addresses across multiple blockchain networks.

Get NFT Metadata

Retrieves metadata for a specific NFT on Ethereum mainnet, including available contract details, media URLs, attributes, and OpenSea data.

Get NFT Metadata Batch

Retrieves metadata for up to 100 NFTs on Ethereum mainnet in a single request, including available contract details, media URLs, attributes, and collection data.

Get NFT Sales V3

Retrieves Ethereum mainnet NFT sales through on-chain marketplaces using Alchemy's v3 API, including fees and transaction details.

Get NFTs for Collection V3

Retrieves NFTs in an Ethereum mainnet collection using an OpenSea collection slug or contract address.

Get NFTs for Contract

Retrieves NFTs for an Ethereum mainnet NFT contract, supporting ERC721 and ERC1155.

Get NFTs for Owner

Retrieves NFTs owned by an address on Ethereum mainnet, supporting ERC721 and ERC1155 tokens, optional metadata, filtering, and pagination.

Get Owners for Collection

Retrieves owner addresses for an Ethereum mainnet NFT collection contract, with optional token balances per owner and pagination.

Get Owners for Contract

Retrieves owners of NFTs in an Ethereum mainnet contract, with optional token balances and pagination.

Get NFT Owners (v3)

Retrieves owner addresses for a specific Ethereum mainnet NFT using Alchemy's v3 API.

Get Portfolio NFTs By Address

Tool to fetch NFTs owned by multiple wallet addresses across different blockchain networks.

Get Token Prices By Symbol

Tool to get current token prices by symbol (e.

Get Token Balances

This tool retrieves ERC20 token balances for a specified Ethereum address.

Get Token Balances By Address

Tool to get token balances for wallet addresses across multiple networks using Alchemy's Portfolio API.

Get Token Metadata

Retrieves Ethereum mainnet ERC-20 token metadata, including available name, symbol, decimals, and logo URL, for display and token amount conversion.

Get Token Prices By Address

Retrieves current token prices by contract address and network from decentralized exchanges (DEXes).

Get Tokens By Address

Tool to fetch fungible tokens (native, ERC-20, SPL) for multiple wallet addresses across networks.

Get Transaction Count

Retrieves an Ethereum mainnet address's transaction count (nonce) at a specified block tag or hexadecimal block number using eth_getTransactionCount.

Get Transactions History By Address

Retrieves transaction history for one wallet address across up to two networks using Alchemy's Data API.

Invalidate NFT Contract Cache

Tool to invalidate the cached metadata for an NFT contract.

Check If NFT Is Airdrop

Tool to check if a specific NFT token is marked as an airdrop.

Check If NFT Is Airdrop

Check whether a specified NFT is marked as an airdrop using its contract address and token ID on Ethereum mainnet.

Check Collection Ownership

Tool to check if a wallet address owns any token from a specific NFT collection.

Check NFT Holder Status

Tool to check if a wallet address holds any NFTs from a specific contract.

Check if Contract is Spam

Tool to check if an NFT contract is marked as spam by Alchemy.

Check if Contract is Spam (V3)

Tool to determine if a specific NFT contract is marked as spam by Alchemy.

Search NFT Contract Metadata

Search Ethereum mainnet NFT contract metadata by keywords to find collections.

Summarize NFT Attributes

Retrieves a summary of NFT attributes for an Ethereum mainnet collection, including trait value counts.

FRAMEWORKS

How to build Alchemy MCP Agent with another framework

Claude Code logo

Claude Code

Use Alchemy MCP with Claude Code

Claude Cowork logo

Claude Cowork

Use Alchemy MCP with Claude Cowork

OpenAI Agents SDK logo

OpenAI Agents SDK

Use Alchemy MCP with OpenAI Agents SDK

Claude Agent SDK logo

Claude Agent SDK

Use Alchemy MCP with Claude Agent SDK

Codex logo

Codex

Use Alchemy MCP with Codex

OpenClaw logo

OpenClaw

Use Alchemy MCP with OpenClaw

Hermes logo

Hermes

Use Alchemy MCP with Hermes

Atomic Agent logo

Atomic Agent

Use Alchemy MCP with Atomic Agent

Google ADK logo

Google ADK

Use Alchemy MCP with Google ADK

LangChain logo

LangChain

Use Alchemy MCP with LangChain

Vercel AI SDK logo

Vercel AI SDK

Use Alchemy MCP with Vercel AI SDK

Mastra AI logo

Mastra AI

Use Alchemy MCP with Mastra AI

LlamaIndex logo

LlamaIndex

Use Alchemy MCP with LlamaIndex

CrewAI logo

CrewAI

Use Alchemy MCP with CrewAI

AutoGen logo

AutoGen

Use Alchemy MCP with AutoGen

FAQ

Frequently asked questions

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

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 Alchemy tools.

Yes, absolutely. You can configure which Alchemy 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 Alchemy data and credentials are handled as safely as possible.

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