How to integrate Checkvist MCP with Pydantic AI

This guide walks you through connecting Checkvist to Pydantic AI using the Composio tool router. By the end, you'll have a working Checkvist agent that can create your checklists, add tasks, search tasks, import task lists, and view task outlines through natural language commands. This guide will help you understand how to give your Pydantic AI agent real control over a Checkvist account through Composio's Checkvist MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

Checkvist logoCheckvist
Api Key

Checkvist is an online outliner and task manager for hierarchical lists, notes, tags, due dates, and assignees. Use it to plan projects, capture ideas, and organize work in clean nested lists.

16 Tools

Introduction

This guide walks you through connecting Checkvist to Pydantic AI using the Composio tool router. By the end, you'll have a working Checkvist agent that can create your checklists, add tasks, search tasks, import task lists, and view task outlines through natural language commands.

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

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

Also integrate Checkvist with

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

The Checkvist MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Checkvist account. It provides structured and secure access to your checklists, tasks, tags, due dates, assignees, and task notes, so your agent can create lists, organize task hierarchies, search tasks, update assignments, and track task status on your behalf.

  • Checklist creation and organization: Have your agent create, rename, tag, review, or delete checklists, including archived and private lists.
  • Hierarchical task planning: Let the agent create individual tasks or import complete task hierarchies, then arrange subtasks, priorities, positions, due dates, tags, and assignees.
  • Task search and review: Instruct your agent to search across checklists by keywords, due dates, tags, status, or notes, and read checklist outlines or task trees.
  • Status and detail updates: Direct your agent to close, reopen, or invalidate tasks, update their content and placement, and add or remove tags.
  • Checklist restructuring and cleanup: Have your agent replace an existing task hierarchy with an updated outline or permanently remove tasks and their subtasks.

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

Create Checklist

Create a Checkvist checklist with a name and optional visibility and tags.

Create Task

Create a task in a checklist, optionally under a parent and with tags, smart-syntax due date, position, priority, or assignees.

Delete Checklist

Mark a Checkvist checklist for deletion.

Delete Task

Permanently delete a Checkvist task and all of its child tasks.

Get Checklist

Get one Checkvist checklist's metadata by ID.

Get Tasks Outline

Read a checklist as a recommended markdown task outline, with controls for closed tasks, depth, compact output, or top-level preview.

Get Tasks Page

Read one explicit 1-based page of a large Checkvist checklist.

Get Task Tree

Read one Checkvist task and its subtasks as a markdown outline, optionally including closed items or notes and limiting depth.

Import Tasks

Create multiple hierarchical tasks from Checkvist indented text.

List Checklists

List checklists available to the authenticated Checkvist user, optionally including archived lists or omitting statistics for a faster response.

Replace Tasks

Delete every existing task in a checklist, then replace the hierarchy from Checkvist indented text or OPML.

Search Tasks

Search tasks across the user's Checkvist checklists using words and operators for due date (^ or due:), tag (# or tag:), state (in:), and notes (has:note).

Set Task Status

Set a task's status to closed, reopened, or invalidated using Checkvist's dedicated status operations.

Update Checklist

Update an existing checklist's name, visibility, or complete tag set.

Update Task

Update task content, hierarchy, replacement tags, due date, position, priority, assignees, or smart-syntax parsing.

Update Task Tags

Add and remove task tags without replacing the complete tag set.

FAQ

Frequently asked questions

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

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

Start with Checkvist.It takes 30 seconds.

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

Start building