How to integrate Alpaca MCP with Pydantic AI

This guide walks you through connecting Alpaca to Pydantic AI using the Composio tool router. By the end, you'll have a working Alpaca agent that can show your current alpaca positions, check latest aapl market price, cancel all open alpaca orders through natural language commands. This guide will help you understand how to give your Pydantic AI agent real control over a Alpaca account through Composio's Alpaca MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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Alpaca is a stock and crypto trading platform for commission-free trading, real-time market data, and algorithmic strategies. Use it to build brokerage apps, trading bots, and portfolio workflows with market connectivity.

100 Tools

Introduction

This guide walks you through connecting Alpaca to Pydantic AI using the Composio tool router. By the end, you'll have a working Alpaca agent that can show your current alpaca positions, check latest aapl market price, cancel all open alpaca orders through natural language commands.

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

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

Also integrate Alpaca 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 Alpaca
  • 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 Alpaca 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 Alpaca MCP server, and what's possible with it?

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

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 Alpaca
  • 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 Alpaca
  • MCPServerStreamableHTTP connects to the Alpaca 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 Alpaca
    composio = Composio(api_key=api_key)
    session = composio.create(
        user_id=user_id,
        toolkits=["alpaca"],
    )
    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 Alpaca 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
alpaca_mcp = MCPServerStreamableHTTP(url, headers={"x-api-key": COMPOSIO_API_KEY})
agent = Agent(
    "openai:gpt-5",
    toolsets=[alpaca_mcp],
    instructions=(
        "You are a Alpaca assistant. Use Alpaca tools to help users "
        "with their requests. Ask clarifying questions when needed."
    ),
)
What's happening:
  • The MCP client connects to the Alpaca endpoint
  • The agent uses GPT-5 to interpret user commands and perform Alpaca 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 Alpaca.\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
  • Alpaca 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 Alpaca 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 Alpaca
    composio = Composio(api_key=api_key)
    session = composio.create(
        user_id=user_id,
        toolkits=["alpaca"],
    )
    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
    alpaca_mcp = MCPServerStreamableHTTP(url, headers={"x-api-key": COMPOSIO_API_KEY})
    agent = Agent(
        "openai:gpt-5",
        toolsets=[alpaca_mcp],
        instructions=(
            "You are a Alpaca assistant. Use Alpaca 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 Alpaca.\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 Alpaca through Composio's Tool Router. With this setup, your agent can perform real Alpaca 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 + Alpaca 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 Alpaca action and event your agent gets out of the box.

Add Asset to Watchlist

Adds a symbol to an existing watchlist in the authenticated account.

Add Asset to Watchlist by Name

Add an asset to a watchlist by name.

Create Watchlist

Creates a new watchlist for the authenticated account.

Create Watchlist

Create a new watchlist for the authenticated account.

Delete All Open Positions

Liquidates all open positions by closing them at market price.

Delete All Orders for Account

Attempts to cancel all open orders for a specified trading account.

Delete Unsubscribe Account

Delete a rebalancing subscription to unsubscribe an account.

Delete Watchlist By ID

Delete a watchlist by its unique identifier.

Get Account

Retrieves account information for the authenticated Alpaca account.

Get Account Activities

Retrieves account activities for the authenticated Alpaca account.

Get Account Activities V2

Retrieves account activities of one type for the authenticated Alpaca account using the v2 API.

Get Account Activities By Activity Type

Retrieves account activities of a specific type for the authenticated Alpaca account.

Get Account Configurations

Retrieves the current trading account configuration settings for the authenticated Alpaca account.

Get Account Portfolio History

Retrieves the portfolio history statistics for an Alpaca trading account.

Get Account Portfolio History

Retrieves the portfolio history statistics for a trading account.

Get All Account Positions

Bulk fetches all open positions for the authenticated account.

Get All Open Positions

Retrieves all open positions for the authenticated Alpaca trading account.

Get All Orders

Retrieves all orders for an account based on specified filter criteria.

Get Historical Crypto US Bars

Retrieves historical OHLCV (Open, High, Low, Close, Volume) bars for crypto symbols in a specific US location.

Get Crypto Bars for Multiple Symbols

Retrieves OHLCV (Open, High, Low, Close, Volume) bars for multiple crypto symbols.

Get Stock Bars for Multiple Symbols

Retrieves OHLCV (Open, High, Low, Close, Volume) bars for multiple stock symbols.

Get Historical Bars for Stock Symbol

Retrieves historical OHLCV (Open, High, Low, Close, Volume) bars for a single stock symbol.

Get Historical Stock Bars

Retrieves historical OHLCV (Open, High, Low, Close, Volume) bars for a single stock symbol.

Get Calendar

Retrieves market calendar information for trading days from the Alpaca Trading API.

Get Clock

Retrieves the current market clock information from the Alpaca Trading API.

Get Stock Conditions

Retrieves the mapping of condition codes to their names from Alpaca Markets API for the specified type (trade or quote conditions) and tape.

Get Crypto Latest Quotes

Retrieves the latest bid and ask prices for specified crypto symbols at a specific location.

Get Crypto Perp Latest Bars

Retrieves the latest OHLCV (Open, High, Low, Close, Volume) bars for crypto perpetual futures symbols.

Get Crypto Perp Latest Orderbooks

Retrieves the latest bid and ask orderbook data for specified crypto perpetual futures symbols.

Get Crypto Perp Latest Pricing

Retrieves the latest pricing data for specified crypto perpetual futures symbols.

Get Crypto Perp Latest Quotes

Retrieves the latest bid and ask prices for specified crypto perpetual futures symbols for a specific location.

Get Crypto Perp Latest Trades

Retrieves the latest trade data for specified crypto perpetual futures symbols.

Get Crypto Perps Global Latest Bars

Retrieves the latest OHLCV (Open, High, Low, Close, Volume) bars for crypto perpetual futures symbols.

Get Crypto Perps Global Latest Pricing

Returns the latest pricing data for crypto perpetual futures symbols.

Get Crypto Perps Global Latest Quotes

Retrieves the latest bid and ask prices for specified crypto perpetual futures symbols.

Get Crypto Perps Global Latest Trades

Retrieves the latest trade data for specified crypto perpetual futures symbols.

Get Crypto Snapshots

Retrieves snapshots (latest trade, latest quote, minute bar, daily bar, and previous daily bar) for multiple cryptocurrency symbols in a specific location.

Get Crypto US Latest Bars

Retrieves the latest OHLCV (Open, High, Low, Close, Volume) bars for US crypto symbols.

Get Crypto US Latest Orderbooks

Retrieves the latest bid and ask orderbook data for specified crypto symbols in the US market.

Get Crypto US Latest Quotes

Retrieves the latest bid and ask prices for specified crypto symbols in the US location.

Get Crypto US Latest Trades

Retrieves the latest trade data for specified crypto symbols in the US location.

Get Crypto US Historical Quotes

Retrieves historical quote data (bid/ask prices) for specified crypto symbols on US exchanges.

Get Crypto US Snapshots

Retrieves snapshots (latest trade, latest quote, minute bar, daily bar, and previous daily bar) for multiple cryptocurrency symbols in the US market location.

Get Crypto US Trades

Retrieves historical trade data for specified US crypto symbols.

Get Exchanges

Retrieves a list of supported stock exchanges with their short codes and full names from the Alpaca Market Data API.

Get Latest Bar for Stock Symbol

Retrieves the latest OHLCV (Open, High, Low, Close, Volume) bar for a single stock symbol.

Get Latest Bars For Crypto Symbol

Retrieves the latest OHLCV (Open, High, Low, Close, Volume) bar data for a crypto symbol.

Get Latest Bars for Crypto Symbols

Retrieves the latest OHLCV (Open, High, Low, Close, Volume) bars for multiple crypto symbols.

Get Latest Bars for Multiple Stock Symbols

Retrieves the latest OHLCV (Open, High, Low, Close, Volume) bars for multiple stock symbols.

Get Crypto Latest Orderbooks

Retrieves the latest bid and ask orderbook data for specified crypto symbols.

Get Crypto Latest Quote

Retrieves the latest bid and ask prices for a specified crypto symbol.

Get Latest Quote for Stock Symbol

Retrieves the latest NBBO (National Best Bid and Offer) quote for a single stock symbol.

Get Crypto Latest Quotes

Retrieves the latest bid and ask prices for specified crypto symbols.

Get Latest Quotes for Multiple Stock Symbols

Retrieves the latest NBBO (National Best Bid and Offer) quotes for multiple stock symbols.

Get Latest Trade for Stock Symbol

Retrieves the latest trade data for a single stock symbol.

Get Latest Crypto Trades

Retrieves the latest trade data for specified crypto symbols.

Get Latest Trades for Multiple Stock Symbols

Retrieves the latest trade data for multiple stock symbols.

Get Market Calendar

Retrieves market calendar information for a specific exchange from the Alpaca Trading API.

Get Meta Exchanges

Retrieves a list of all US stock exchanges and their identifying information from the Alpaca Market Data API.

Get Most Active Stocks

Retrieves the most active stocks by trading volume or trade count.

Get News

Retrieves news articles for specified crypto symbols from the Alpaca Market Data API.

Get Open Position

Fetches a single open position by symbol or asset ID.

Get Options Historical Bars

Retrieves historical OHLCV (Open, High, Low, Close, Volume) bars for options contracts.

Get Option Chain

Retrieves the option chain for a specific underlying symbol including quotes and greeks for all available strikes and expirations.

Get Option Contract

Get an option contract by its symbol or unique identifier.

Get Option Latest Quotes

Retrieves the latest bid and ask prices for specified option symbols.

Get Options Meta Conditions

Retrieves the mapping of condition codes to their names from Alpaca Markets API for the specified tick type (trade or quote conditions).

Get Option Contracts

Retrieve option contracts from Alpaca Markets API (BETA).

Get Options Latest Trades

Retrieves the latest trade for each requested option contract symbol.

Get Options Meta Conditions Trade

Retrieves the mapping of trade condition codes to their names from Alpaca Markets API.

Get Options Snapshots

Retrieves snapshots (latest trade, latest quote, minute bar, daily bar, and previous daily bar) for multiple option contract symbols.

Get Options Snapshots by Underlying Symbol

Retrieves the option chain snapshot data for a specific underlying symbol.

Get Options Historical Trades

Retrieves historical trade data for option contracts.

Get PDT Status

Retrieves the Pattern Day Trader (PDT) status for a specified Alpaca trading account.

List account positions

Lists all open positions for a specified trading account.

Get Quotes for Multiple Stock Symbols

Retrieves historical quote (bid/ask) data for multiple stock symbols.

Get Quotes for Stock Symbol

Retrieves historical NBBO (National Best Bid and Offer) quotes for a specific stock symbol.

Get Stock Snapshot for Symbol

Retrieves a snapshot (latest trade, latest quote, minute bar, daily bar, and previous daily bar) for a single stock symbol.

Get Crypto Snapshots

Retrieves snapshots (latest trade, latest quote, minute bar, daily bar, and previous daily bar) for multiple cryptocurrency symbols.

Get Stock Snapshots for Multiple Symbols

Retrieves snapshots (latest trade, latest quote, minute bar, daily bar, and previous daily bar) for multiple stock symbols.

Get Specific Announcement

Retrieves a specific corporate action announcement by its unique identifier.

Get Stock Auctions

Retrieves historical auction data for specified stock symbols.

Get Stock Auctions for Symbol

Retrieves historical auction (opening/closing print) data for a single stock symbol.

Get Stocks Meta Conditions Trade

Retrieves the mapping of trade condition codes to their names from Alpaca Markets API.

Get Subscription

Retrieves a rebalancing subscription by its unique ID.

Get Top Movers By Market Type

Retrieves the top market movers (gainers and losers) for a specified market type.

Get Trades for Multiple Crypto Symbols

Retrieves historical trade data for specified crypto symbols.

Get Trades for Multiple Stock Symbols

Retrieves historical trade data for multiple stock symbols.

Get Historical Trades for Stock Symbol

Retrieves historical trade data for a single stock symbol.

Get Watchlist By ID

Retrieves a single watchlist by its unique identifier.

Get Watchlist By Name

Retrieves a specific watchlist by its name.

Get Watchlists

Retrieves all watchlists associated with the authenticated account.

Update Account Configurations

Update the trading account configuration settings for the authenticated account.

Remove Asset From Watchlist

Removes a symbol from an existing watchlist in Alpaca.

Remove Symbol From Watchlist

Tool to remove a symbol from an existing watchlist in Alpaca.

Update Trading Configurations

Updates trading account configurations for an Alpaca trading account.

Update Watchlist By ID

Updates an existing watchlist by its unique identifier.

Update Watchlist By Name

Updates an existing watchlist by its name.

Update Watchlist By Name (v2)

Updates an existing watchlist by its name.

Upload Account CIP Information

Upload CIP (Customer Identification Program) information for an account to complete identity verification.

FRAMEWORKS

How to build Alpaca MCP Agent with another framework

OpenAI Agents SDK logo

OpenAI Agents SDK

Use Alpaca MCP with OpenAI Agents SDK

Claude Agent SDK logo

Claude Agent SDK

Use Alpaca MCP with Claude Agent SDK

Claude Code logo

Claude Code

Use Alpaca MCP with Claude Code

Claude Cowork logo

Claude Cowork

Use Alpaca MCP with Claude Cowork

Codex logo

Codex

Use Alpaca MCP with Codex

OpenClaw logo

OpenClaw

Use Alpaca MCP with OpenClaw

Hermes logo

Hermes

Use Alpaca MCP with Hermes

CLI logo

CLI

Use Alpaca MCP with CLI

Google ADK logo

Google ADK

Use Alpaca MCP with Google ADK

LangChain logo

LangChain

Use Alpaca MCP with LangChain

Vercel AI SDK logo

Vercel AI SDK

Use Alpaca MCP with Vercel AI SDK

Mastra AI logo

Mastra AI

Use Alpaca MCP with Mastra AI

LlamaIndex logo

LlamaIndex

Use Alpaca MCP with LlamaIndex

CrewAI logo

CrewAI

Use Alpaca MCP with CrewAI

FAQ

Frequently asked questions

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

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

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Karan skipped his own birthday party to fix our critical issue. It was 10pm and he diverted his Waymo to help us instead. This really sets the bar — it shows the commitment you need when users rely on your software.

Harsha Gaddipati
Harsha Gaddipati
Co-founder, Slashy

A lot of students tell us that the moment their connected tools start talking to each other inside Opennote feels almost magical. The agent just knows them, and it's immensely helped keep new users on the platform.

Abhi Arya
Abhi Arya
Co-founder, Opennote

We chose Composio over Pipedream because it delivered depth where it mattered — niche tools and tricky edge cases other platforms simply ignored. That gave us confidence to scale without compromising.

Nirman Dave
Nirman Dave
CEO, Zams

As a solo builder, shipping fast is life or death. The only way I can outcompete incumbents is by outmanoeuvring them. Getting bogged down managing agent auth would have been a death sentence.

Ryan Yu
Ryan Yu
Founder, Extra Thursday

Before Composio, adding tool integrations was slow and resource-intensive. Each one could take weeks of engineering time, and maintaining them meant constantly keeping up with API changes.

Tomisin Jenrola
Tomisin Jenrola
Founder & CEO, SwarmZero

With hands-on help from their founder, we integrated Gmail and Google Drive in just 30 minutes. This level of personal support and commitment is exactly what startups should strive for.

Jerome Leclanche
Jerome Leclanche
Co-Founder, Ingram Technologies