How to integrate Sequenzy MCP with Pydantic AI

This guide walks you through connecting Sequenzy to Pydantic AI using the Composio tool router. By the end, you'll have a working Sequenzy agent that can list your campaigns and sequences, browse subscribers, review email metrics, and manage tags through natural language commands. This guide will help you understand how to give your Pydantic AI agent real control over a Sequenzy account through Composio's Sequenzy MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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Api Key

Sequenzy is an email marketing and automation platform for subscribers, campaigns, sequences, transactional email, analytics, and workspace resources. Use it to manage lifecycle email, audience growth, and performance tracking from one place.

10 Tools

Introduction

This guide walks you through connecting Sequenzy to Pydantic AI using the Composio tool router. By the end, you'll have a working Sequenzy agent that can list your campaigns and sequences, browse subscribers, review email metrics, and manage tags through natural language commands.

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

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

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

The Sequenzy MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Sequenzy account. It provides structured and secure access to your subscribers, campaigns, sequences, templates, tags, lists, and email metrics, so your agent can review audiences, inspect marketing activity, find reusable content, manage tags, and analyze email performance on your behalf.

  • Subscriber and audience review: Have your agent search subscribers, retrieve individual profiles with memberships and recent activity, and review the lists available for audience targeting.
  • Campaign and sequence discovery: Let the agent find campaigns by delivery status or label, then inspect sequences to see whether they accept new enrollments or process existing ones.
  • Email performance analysis: Instruct your agent to review delivery and engagement totals and rates for a recent period or custom date range, with optional filters for email type or mailbox provider.
  • Template discovery: Direct your agent to find reusable email templates and campaign email content by label, including available localization details.
  • Subscriber tag management: Have your agent list available tags, create normalized tag definitions, or delete non-system tags that are no longer needed.

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

Create Tag

Create a reusable subscriber tag definition; Sequenzy normalizes its name to lowercase and replaces spaces with hyphens.

Delete Tag

Permanently delete a non-system tag definition and remove it from every subscriber.

Get Email Metrics

Return workspace-wide email delivery and engagement totals and rates for a sliding window or custom range, optionally filtered by email type or mailbox provider.

Get Subscriber

Retrieve one subscriber by email with list memberships, sequence enrollments, notes, engagement totals, and recent activity.

List Campaigns

Discover campaigns in the connected workspace, optionally filtered by delivery status or label, without scheduling or sending them.

List Sequences

Discover automation sequences and inspect whether they accept new enrollments or process existing ones, without activating or enrolling anyone.

List Subscriber Lists

Return the reusable subscriber lists available for audience filtering and membership workflows.

List Subscribers

Search and filter subscribers in the connected workspace, returning one stable cursor page for audience review or export.

List Tags

Return reusable subscriber tag definitions, including which tags are protected system tags.

List Templates

Discover reusable email templates and campaign-backed email bodies by label, returning one page with localization metadata.

FAQ

Frequently asked questions

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

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

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