How to integrate Missive MCP with Pydantic AI

This guide walks you through connecting Missive to Pydantic AI using the Composio tool router. By the end, you'll have a working Missive agent that can list all team members for marketing, create a draft email for client follow-up, send a chat message in project conversation through natural language commands. This guide will help you understand how to give your Pydantic AI agent real control over a Missive account through Composio's Missive MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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Missive

Api Key

Missive is a collaborative email and chat app for teams to manage conversations and tasks together. It helps streamline team inboxes, shared labels, and internal discussion in one place.

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Introduction

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

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

Also integrate Missive with

OpenAI Agents SDK Claude Agent SDK Claude Code Claude Cowork Codex OpenClaw Hermes CLI Google ADK LangChain Vercel AI SDK Mastra AI LlamaIndex CrewAI

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 Missive
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 Missive 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 Missive MCP server, and what's possible with it?

The Missive MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Missive account. It provides structured and secure access to your team's shared inboxes and chat threads, so your agent can perform actions like drafting emails, sending messages, generating reports, and managing team communication on your behalf.

Automated message drafting and scheduling: Let your agent create and save email, SMS, WhatsApp, or live chat drafts for later editing or scheduled sending.
Instant message sending in conversations: Have your agent send new messages directly to any Missive conversation, keeping your team in the loop in real time.
Team and user management: Effortlessly list all teams and their members, or pull a full directory of users in your Missive organization for easy coordination and task assignment.
Analytics report generation: Direct your agent to create detailed analytics reports across time ranges and filters, helping your team track productivity and engagement.
Webhook automation setup: Enable your agent to create or delete webhook subscriptions, so you can automate notifications and integrations with other tools as 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:

Discovery: Searches for tools matching your task and returns relevant toolkits with their details.
Authentication: Checks for active connections. If missing, creates an auth config and returns a connection URL via Auth Link.
Execution: Executes the action using the authenticated connection.

Step-by-step Guide

Step by step09 STEPS

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

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.

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 Missive
pydantic-ai lets you create structured AI agents with tool support
python-dotenv loads your environment variables securely from a .env file

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

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 Missive
MCPServerStreamableHTTP connects to the Missive MCP server endpoint
Agent from Pydantic AI lets you define and run the AI assistant

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 Missive
    composio = Composio(api_key=api_key)
    session = composio.create(
        user_id=user_id,
        toolkits=["missive"],
    )
    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 Missive 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

Initialize the Pydantic AI Agent

python

# Attach the MCP server to a Pydantic AI Agent
missive_mcp = MCPServerStreamableHTTP(url, headers={"x-api-key": COMPOSIO_API_KEY})
agent = Agent(
    "openai:gpt-5",
    toolsets=[missive_mcp],
    instructions=(
        "You are a Missive assistant. Use Missive tools to help users "
        "with their requests. Ask clarifying questions when needed."
    ),
)

What's happening:

The MCP client connects to the Missive endpoint
The agent uses GPT-5 to interpret user commands and perform Missive operations
The instructions field defines the agent's role and behavior

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 Missive.\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
Missive API calls happen automatically under the hood
The model keeps conversation history to maintain context across turns

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 Missive 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 Missive
    composio = Composio(api_key=api_key)
    session = composio.create(
        user_id=user_id,
        toolkits=["missive"],
    )
    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
    missive_mcp = MCPServerStreamableHTTP(url, headers={"x-api-key": COMPOSIO_API_KEY})
    agent = Agent(
        "openai:gpt-5",
        toolsets=[missive_mcp],
        instructions=(
            "You are a Missive assistant. Use Missive 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 Missive.\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 Missive through Composio's Tool Router. With this setup, your agent can perform real Missive 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 + Missive 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 Missive action and event your agent gets out of the box.

Create Analytics Report

Tool to create an analytics report.

Create Missive Contacts

Tool to create one or more contacts in a Missive contact book.

Create Draft

Tool to create a new draft in Missive.

Create Missive Post

Tool to create a post in a Missive conversation.

Create Canned Response

Tool to create one or more canned responses (templates) in Missive.

Create Shared Label

Tool to create one or more shared labels at the organization level.

Create Missive Task

Tool to create a task in Missive.

Create Team

Tool to create a new team in an organization.

Create Webhook

Tool to create a webhook subscription.

Delete Draft

Tool to delete a draft from a conversation by draft ID.

Delete Post

Tool to delete a post from a conversation by post ID.

Delete Saved Responses

Tool to delete one or more saved responses by ID.

Delete Webhook

Tool to delete a webhook subscription by webhook ID.

Get Analytics Report

Tool to fetch a completed analytics report using its ID.

Get Missive Contact

Tool to fetch a specific contact using the contact ID.

Get Missive Conversation

Tool to fetch full conversation metadata (assignees/users/labels/team/org) for a specific conversation ID.

List Conversation Messages

Tool to list messages belonging to a Missive conversation (newest first).

Get Missive Message

Tool to fetch full message details including headers, HTML body, and attachments.

Get Missive Response

Tool to fetch a specific saved response using the response ID.

Get Missive Task

Tool to get a single task by ID with full details including assignees, team, and conversation info.

List Missive Contact Books

Tool to list contact books the authenticated user has access to.

List Missive Contact Groups

Tool to list contact groups or organizations linked to a contact book.

List Missive Contacts

Tool to list contacts from a contact book.

List Conversation Comments

Tool to list comments in a Missive conversation ordered from newest to oldest.

List Conversation Drafts

Tool to list draft messages in a Missive conversation (newest first).

List Conversation Posts

Tool to list posts in a Missive conversation ordered by newest first.

List Missive Conversations

Tool to list conversations visible to the authenticated user ordered by newest activity first.

List Messages by Message-ID

Tool to fetch messages matching an email Message-ID header.

List Missive Organizations

Tool to list organizations the authenticated user is part of.

List Missive Saved Responses

Tool to list saved responses (canned responses/templates) for the authenticated user.

List Missive Shared Labels

Tool to list shared labels (organization-level labels) available to the authenticated user.

List Missive Tasks

Tool to list tasks accessible to the authenticated user.

List Missive Teams

Tool to list all teams.

List Missive Users

Tool to list all users.

Merge Missive Conversations

Tool to merge multiple conversations into one.

Update Missive Contact

Tool to update one or more contacts in Missive.

Update Saved Response

Tool to update one or more saved responses in Missive.

Update Shared Labels

Tool to update one or more shared labels in Missive.

Update Missive Task

Tool to update an existing task's attributes in Missive.

Update Missive Team

Tool to update one or more teams in Missive.

FRAMEWORKS

How to build Missive MCP Agent with another framework

OpenAI Agents SDK

Use Missive MCP with OpenAI Agents SDK

Claude Agent SDK

Use Missive MCP with Claude Agent SDK

Claude Code

Use Missive MCP with Claude Code

Claude Cowork

Use Missive MCP with Claude Cowork

Codex

Use Missive MCP with Codex

OpenClaw

Use Missive MCP with OpenClaw

Hermes

Use Missive MCP with Hermes

CLI

Use Missive MCP with CLI

Google ADK

Use Missive MCP with Google ADK

LangChain

Use Missive MCP with LangChain

Vercel AI SDK

Use Missive MCP with Vercel AI SDK

Mastra AI

Use Missive MCP with Mastra AI

LlamaIndex

Use Missive MCP with LlamaIndex

CrewAI

Use Missive MCP with CrewAI

MORE TOOLKITS

Explore Other Toolkits

Toolkit marketplace

Gmail

Oauth2

Gmail is Google's email service with powerful spam protection, search, and G Suite integration. It keeps your inbox organized and makes communication fast and reliable.

Outlook

Oauth2S2s Oauth2

Outlook is Microsoft's email and calendaring platform for unified communications and scheduling. It helps users stay organized with powerful email, contacts, and calendar management.

Slack

Oauth2

Slack is a channel-based messaging platform for teams and organizations. It helps people collaborate in real time, share files, and connect all their tools in one place.

Gong

BasicOauth2

Gong is a platform for video meetings, call recording, and team collaboration. It helps teams capture conversations, analyze calls, and turn insights into action.

FAQ

Frequently asked questions

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

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

Start with Missive.It takes 30 seconds.

Managed auth, hosted MCP servers, and every Missive tool your agent needs.Free to start.

Start building

Customer stories

Teams ship real agents on Composio

GET STARTED FOR FREE BOOK A DEMO

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

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

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

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

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

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

Co-Founder, Ingram Technologies

How to integrate Missive MCP with Pydantic AI

Connect Missive without auth hassles

Introduction

Also integrate Missive with

TL;DR

What is Pydantic AI?

What is the Missive MCP server, and what's possible with it?

What is the Composio tool router, and how does it fit here?

What is Composio SDK?

How the Composio SDK works

Step-by-step Guide

Prerequisites

Getting API Keys for OpenAI and Composio

Install dependencies

Set up environment variables

Import dependencies

Create a Tool Router Session

Initialize the Pydantic AI Agent

Build the chat interface

Run the application

Complete Code

Conclusion

Supported Tools

How to build Missive MCP Agent with another framework

OpenAI Agents SDK

Claude Agent SDK

Claude Code

Claude Cowork

Codex

OpenClaw

Hermes

CLI

Google ADK

LangChain

Vercel AI SDK

Mastra AI

LlamaIndex

CrewAI

Explore Other Toolkits

Gmail

Outlook

Slack

Gong

Frequently asked questions

What are the differences in Tool Router MCP and Missive MCP?+

Can I use Tool Router MCP with Pydantic AI?+

Can I manage the permissions and scopes for Missive while using Tool Router?+

How safe is my data with Composio Tool Router?+

Start with Missive.It takes 30 seconds.

Teams ship real agents on Composio