# How to integrate Marketstack MCP with Pydantic AI

```json
{
  "title": "How to integrate Marketstack MCP with Pydantic AI",
  "toolkit": "Marketstack",
  "toolkit_slug": "marketstack",
  "framework": "Pydantic AI",
  "framework_slug": "pydantic-ai",
  "url": "https://composio.dev/toolkits/marketstack/framework/pydantic-ai",
  "markdown_url": "https://composio.dev/toolkits/marketstack/framework/pydantic-ai.md",
  "updated_at": "2026-03-29T06:41:39.139Z"
}
```

## Introduction

This guide walks you through connecting Marketstack to Pydantic AI using the Composio tool router. By the end, you'll have a working Marketstack agent that can get the latest price for aapl, show historical prices for tsla last month, list top gainers on nyse today through natural language commands.
This guide will help you understand how to give your Pydantic AI agent real control over a Marketstack account through Composio's Marketstack MCP server.
Before we dive in, let's take a quick look at the key ideas and tools involved.

## Also integrate Marketstack with

- [OpenAI Agents SDK](https://composio.dev/toolkits/marketstack/framework/open-ai-agents-sdk)
- [Claude Agent SDK](https://composio.dev/toolkits/marketstack/framework/claude-agents-sdk)
- [Claude Code](https://composio.dev/toolkits/marketstack/framework/claude-code)
- [Claude Cowork](https://composio.dev/toolkits/marketstack/framework/claude-cowork)
- [Codex](https://composio.dev/toolkits/marketstack/framework/codex)
- [OpenClaw](https://composio.dev/toolkits/marketstack/framework/openclaw)
- [Hermes](https://composio.dev/toolkits/marketstack/framework/hermes-agent)
- [CLI](https://composio.dev/toolkits/marketstack/framework/cli)
- [Google ADK](https://composio.dev/toolkits/marketstack/framework/google-adk)
- [LangChain](https://composio.dev/toolkits/marketstack/framework/langchain)
- [Vercel AI SDK](https://composio.dev/toolkits/marketstack/framework/ai-sdk)
- [Mastra AI](https://composio.dev/toolkits/marketstack/framework/mastra-ai)
- [LlamaIndex](https://composio.dev/toolkits/marketstack/framework/llama-index)
- [CrewAI](https://composio.dev/toolkits/marketstack/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 Marketstack
- 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 Marketstack 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 Marketstack MCP server, and what's possible with it?

The Marketstack MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Marketstack account. It provides structured and secure access so your agent can perform Marketstack operations on your behalf.

## Supported Tools

| Tool slug | Name | Description |
|---|---|---|
| `MARKETSTACK_GET_DIVIDENDS` | Get Dividends | Tool to retrieve stock dividend data for one or more ticker symbols from Marketstack API. Use when you need historical dividend payment information for stocks, including dividend amounts and payment dates. |
| `MARKETSTACK_GET_EOD` | Get End-of-Day Data | Tool to retrieve end-of-day (EOD) stock data for one or multiple ticker symbols. Returns OHLCV data (open, high, low, close, volume) along with adjusted prices, dividends, and split factors. Use when you need historical daily stock prices or market data analysis. |
| `MARKETSTACK_GET_EXCHANGE` | Get Exchange Info | Tool to retrieve detailed information for a specific stock exchange by its MIC (Market Identifier Code). Use when you need comprehensive information about an exchange including its location, status, and operational details. |
| `MARKETSTACK_GET_SPLITS` | Get Stock Splits | Tool to retrieve stock split data for one or more stock symbols from Marketstack. Use when you need historical split information including split factors and dates. |
| `MARKETSTACK_GET_TICKER_EOD_DATA` | Get Ticker EOD Data | Tool to retrieve end-of-day stock price data for a specific ticker symbol. Use when you need historical daily price information including open, high, low, close, volume, and adjusted values. |
| `MARKETSTACK_GET_TICKER_EOD_LATEST` | Get Ticker EOD Latest | Tool to retrieve end-of-day (EOD) stock data for the latest available date for a specific ticker. Use when you need the most recent trading day data for a stock symbol. |
| `MARKETSTACK_GET_TICKER_INFO` | Get Ticker Info | Tool to retrieve detailed information about stock tickers including exchange, sector, and industry data. Use when you need comprehensive company information for a ticker symbol. |
| `MARKETSTACK_LIST_CURRENCIES` | List Currencies | Tool to retrieve a list of all supported currencies from the Marketstack API. Use when you need to get information about available currencies for stock market data. |
| `MARKETSTACK_LIST_STOCK_EXCHANGES` | List Stock Exchanges | Tool to retrieve information about supported stock exchanges. Use when you need to list or search for stock exchanges from the 2700+ exchanges available in Marketstack. |
| `MARKETSTACK_LIST_TICKERS` | List Tickers | Tool to get a list of all supported stock tickers. Use when you need to obtain the full list of tickers supported by Marketstack or search for specific tickers. |

## Supported Triggers

None listed.

## Creating MCP Server - Stand-alone vs Composio SDK

The Marketstack MCP server is an implementation of the Model Context Protocol that connects your AI agent to Marketstack. It provides structured and secure access so your agent can perform Marketstack 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 Marketstack
- 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 Marketstack
- MCPServerStreamableHTTP connects to the Marketstack 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 Marketstack 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 Marketstack
    composio = Composio(api_key=api_key)
    session = composio.create(
        user_id=user_id,
        toolkits=["marketstack"],
    )
    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 Marketstack endpoint
- The agent uses GPT-5 to interpret user commands and perform Marketstack operations
- The instructions field defines the agent's role and behavior
```python
# Attach the MCP server to a Pydantic AI Agent
marketstack_mcp = MCPServerStreamableHTTP(url, headers={"x-api-key": COMPOSIO_API_KEY})
agent = Agent(
    "openai:gpt-5",
    toolsets=[marketstack_mcp],
    instructions=(
        "You are a Marketstack assistant. Use Marketstack 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
- Marketstack 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 Marketstack.\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 Marketstack
    composio = Composio(api_key=api_key)
    session = composio.create(
        user_id=user_id,
        toolkits=["marketstack"],
    )
    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
    marketstack_mcp = MCPServerStreamableHTTP(url, headers={"x-api-key": COMPOSIO_API_KEY})
    agent = Agent(
        "openai:gpt-5",
        toolsets=[marketstack_mcp],
        instructions=(
            "You are a Marketstack assistant. Use Marketstack 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 Marketstack.\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 Marketstack through Composio's Tool Router. With this setup, your agent can perform real Marketstack 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 + Marketstack 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 Marketstack MCP Agent with another framework

- [OpenAI Agents SDK](https://composio.dev/toolkits/marketstack/framework/open-ai-agents-sdk)
- [Claude Agent SDK](https://composio.dev/toolkits/marketstack/framework/claude-agents-sdk)
- [Claude Code](https://composio.dev/toolkits/marketstack/framework/claude-code)
- [Claude Cowork](https://composio.dev/toolkits/marketstack/framework/claude-cowork)
- [Codex](https://composio.dev/toolkits/marketstack/framework/codex)
- [OpenClaw](https://composio.dev/toolkits/marketstack/framework/openclaw)
- [Hermes](https://composio.dev/toolkits/marketstack/framework/hermes-agent)
- [CLI](https://composio.dev/toolkits/marketstack/framework/cli)
- [Google ADK](https://composio.dev/toolkits/marketstack/framework/google-adk)
- [LangChain](https://composio.dev/toolkits/marketstack/framework/langchain)
- [Vercel AI SDK](https://composio.dev/toolkits/marketstack/framework/ai-sdk)
- [Mastra AI](https://composio.dev/toolkits/marketstack/framework/mastra-ai)
- [LlamaIndex](https://composio.dev/toolkits/marketstack/framework/llama-index)
- [CrewAI](https://composio.dev/toolkits/marketstack/framework/crew-ai)

## Related Toolkits

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- [Tavily](https://composio.dev/toolkits/tavily) - Tavily offers powerful search and data retrieval from documents, databases, and the web. It helps teams locate and filter information instantly, saving hours on research.
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- [Benzinga](https://composio.dev/toolkits/benzinga) - Benzinga provides real-time financial news and data APIs for market coverage. It helps you track breaking news and actionable market insights instantly.
- [Brex](https://composio.dev/toolkits/brex) - Brex provides corporate credit cards and spend management tailored for startups and tech businesses. It helps optimize company cash flow, streamline accounting, and accelerate business growth.
- [Bright Data MCP](https://composio.dev/toolkits/brightdata_mcp) - Bright Data MCP is an AI-powered web scraping and data collection platform. Instantly access public web data in real time with advanced scraping tools.
- [Browseai](https://composio.dev/toolkits/browseai) - Browseai is a web automation and data extraction platform that turns any website into an API. It's perfect for monitoring websites and retrieving structured data without manual scraping.
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- [ClickHouse](https://composio.dev/toolkits/clickhouse) - ClickHouse is an open-source, column-oriented database for real-time analytics and big data processing using SQL. Its lightning-fast query performance makes it ideal for handling large datasets and delivering instant insights.
- [Clientary](https://composio.dev/toolkits/clientary) - Clientary is a platform for managing clients, invoices, projects, proposals, and more. It streamlines client work and saves you serious admin time.
- [Coinbase](https://composio.dev/toolkits/coinbase) - Coinbase is a platform for buying, selling, and storing cryptocurrency. It makes exchanging and managing crypto simple and secure for everyone.
- [Coinmarketcal](https://composio.dev/toolkits/coinmarketcal) - CoinMarketCal is a community-powered crypto calendar for upcoming events, announcements, and releases. It helps traders track market-moving developments and stay ahead in the crypto space.

## Frequently Asked Questions

### What are the differences in Tool Router MCP and Marketstack MCP?

With a standalone Marketstack MCP server, the agents and LLMs can only access a fixed set of Marketstack tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Marketstack 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 Marketstack tools.

### Can I manage the permissions and scopes for Marketstack while using Tool Router?

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

---
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