How to integrate Notion MCP with LangChain

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Introduction

This guide walks you through connecting Notion to LangChain using the Composio tool router. By the end, you'll have a working Notion agent that can add meeting notes to project wiki page, create a new task database for q3, archive completed sprint summary pages, duplicate onboarding checklist for new hire through natural language commands.

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

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

TL;DR

Here's what you'll learn:
  • Get and set up your OpenAI and Composio API keys
  • Connect your Notion project to Composio
  • Create a Tool Router MCP session for Notion
  • Initialize an MCP client and retrieve Notion tools
  • Build a LangChain agent that can interact with Notion
  • Set up an interactive chat interface for testing

What is LangChain?

LangChain is a framework for developing applications powered by language models. It provides tools and abstractions for building agents that can reason, use tools, and maintain conversation context.

Key features include:

  • Agent Framework: Build agents that can use tools and make decisions
  • MCP Integration: Connect to external services through Model Context Protocol adapters
  • Memory Management: Maintain conversation history across interactions
  • Multi-Provider Support: Works with OpenAI, Anthropic, and other LLM providers

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

The Notion MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Notion account. It provides structured and secure access to your notes, docs, wikis, and tasks, so your agent can perform actions like creating pages, managing databases, adding content, commenting, and organizing your Notion workspace for you.

  • Bulk content creation and formatting: Let your agent efficiently add and format multiple blocks of text, lists, or markdown content to Notion pages in one go.
  • Automated page and database management: Have your agent create new pages, duplicate existing ones, or set up entire databases with custom properties—no manual setup required.
  • Smart commenting and collaboration: Enable your agent to add comments to pages or discussion threads, making real-time collaboration smoother.
  • Workspace organization and cleanup: Ask your agent to archive, delete, or restore pages and blocks, keeping your workspace tidy and up to date.
  • Deep block and structure retrieval: Direct your agent to fetch metadata, list child blocks, or dig into nested content for analysis, reporting, or workflow automation.

Supported Tools & Triggers

Tools
Triggers
Add multiple content blocks (bulk, user-friendly)Efficiently adds multiple standard content blocks to a notion page in a single api call with automatic markdown parsing.
Append complex blocks (advanced, full control)Appends complex blocks with full notion block structure to a parent block or page.
Archive Notion PageArchives (moves to trash) or unarchives (restores from trash) a specified notion page.
Create commentAdds a comment to a notion page (via `parent page id`) or to an existing discussion thread (via `discussion id`); cannot create new discussion threads on specific blocks (inline comments).
Create Notion DatabaseCreates a new notion database as a subpage under a specified parent page with a defined properties schema; use this action exclusively for creating new databases.
Create Notion pageCreates a new empty page in a notion workspace.
Delete a blockArchives a notion block, page, or database using its id, which sets its 'archived' property to true (like moving to "trash" in the ui) and allows it to be restored later.
Duplicate pageDuplicates a notion page, including all its content, properties, and nested blocks, under a specified parent page or workspace.
Fetch Notion Block ChildrenRetrieves a paginated list of direct, first-level child block objects along with contents for a given parent notion block or page id; use block ids from the response for subsequent calls to access deeply nested content.
Fetch Notion block metadataFetches metadata for a notion block (or page, as pages are blocks) using its valid uuid; if the block has children, use fetch block contents to fetch their contents.
Fetch commentsFetches unresolved comments for a specified notion block or page id.
Fetch Notion DataFetches notion items (pages and/or databases) from the notion workspace, use this to get minimal data about the items in the workspace with a query or list all items in the workspace with minimal data
Fetch DatabaseFetches a notion database's structural metadata (properties, title, etc.
Fetch database rowRetrieves a notion database row's properties and metadata; use fetch block contents for page content blocks.
Get About MeRetrieves the user object for the bot associated with the current notion integration token, typically to obtain the bot's user id for other api operations.
Get about userRetrieves detailed information about a specific notion user, such as their name, avatar, and email, based on their unique user id.
Get page propertyCall this to get a specific property from a notion page when you have a valid `page id` and `property id`; handles pagination for properties returning multiple items.
Insert row databaseCreates a new page (row) in a specified notion database.
List usersRetrieves a paginated list of users (excluding guests) from the notion workspace; the number of users returned per page may be less than the requested `page size`.
Query databaseQueries a notion database for pages (rows), where rows are pages and columns are properties; ensure sort property names correspond to existing database properties.
Retrieve CommentTool to retrieve a specific comment by its id.
Retrieve Database PropertyTool to retrieve a specific property object of a notion database.
Search Notion pageSearches notion pages and databases by title; an empty query lists all accessible items, useful for discovering ids or as a fallback when a specific query yields no results.
Update blockUpdates an existing notion block's textual content or type-specific properties (e.
Update PageTool to update the properties, icon, cover, or archive status of a page.
Update row databaseUpdates or archives an existing notion database row (page) using its `row id`, allowing modification of its icon, cover, and/or properties; ensure the target page is accessible and property details (names/ids and values) align with the database schema and specified formats.
Update database schemaUpdates an existing notion database's title, description, and/or properties; at least one of these attributes must be provided to effect a change.

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

What is Tool Router?

Composio's Tool Router 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 Tool Router

The tool router generates a secure MCP URL that your agents can access to perform actions.

How the Tool Router works

The Tool Router 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

Prerequisites

Before starting this tutorial, make sure you have:
  • Python 3.10 or higher installed on your system
  • A Composio account with an API key
  • An OpenAI 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

pip install composio-langchain langchain-mcp-adapters langchain python-dotenv

Install the required packages for LangChain with MCP support.

What's happening:

  • composio-langchain provides Composio integration for LangChain
  • langchain-mcp-adapters enables MCP client connections
  • langchain is the core agent framework
  • python-dotenv loads environment variables

Set up environment variables

bash
COMPOSIO_API_KEY=your_composio_api_key_here
COMPOSIO_USER_ID=your_composio_user_id_here
OPENAI_API_KEY=your_openai_api_key_here

Create a .env file in your project root.

What's happening:

  • COMPOSIO_API_KEY authenticates your requests to Composio's API
  • COMPOSIO_USER_ID identifies the user for session management
  • OPENAI_API_KEY enables access to OpenAI's language models

Import dependencies

from langchain_mcp_adapters.client import MultiServerMCPClient
from langchain.agents import create_agent
from dotenv import load_dotenv
from composio import Composio
import asyncio
import os

load_dotenv()
What's happening:
  • We're importing LangChain's MCP adapter and Composio SDK
  • The dotenv import loads environment variables from your .env file
  • This setup prepares the foundation for connecting LangChain with Notion functionality through MCP

Initialize Composio client

async def main():
    composio = Composio(api_key=os.getenv("COMPOSIO_API_KEY"))

    if not os.getenv("COMPOSIO_API_KEY"):
        raise ValueError("COMPOSIO_API_KEY is not set")
    if not os.getenv("COMPOSIO_USER_ID"):
        raise ValueError("COMPOSIO_USER_ID is not set")
What's happening:
  • We're loading the COMPOSIO_API_KEY from environment variables and validating it exists
  • Creating a Composio instance that will manage our connection to Notion tools
  • Validating that COMPOSIO_USER_ID is also set before proceeding

Create a Tool Router session

# Create Tool Router session for Notion
session = composio.create(
    user_id=os.getenv("COMPOSIO_USER_ID"),
    toolkits=['notion']
)

url = session.mcp.url
What's happening:
  • We're creating a Tool Router session that gives your agent access to Notion 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
  • This approach allows the agent to dynamically load and use Notion tools as needed

Configure the agent with the MCP URL

client = MultiServerMCPClient({
    "notion-agent": {
        "transport": "streamable_http",
        "url": session.mcp.url,
        "headers": {
            "x-api-key": os.getenv("COMPOSIO_API_KEY")
        }
    }
})

tools = await client.get_tools()

agent = create_agent("gpt-5", tools)
What's happening:
  • We're creating a MultiServerMCPClient that connects to our Notion MCP server via HTTP
  • The client is configured with a name and the URL from our Tool Router session
  • get_tools() retrieves all available Notion tools that the agent can use
  • We're creating a LangChain agent using the GPT-5 model

Set up interactive chat interface

conversation_history = []

print("Chat started! Type 'exit' or 'quit' to end the conversation.\n")
print("Ask any Notion related question or task to the agent.\n")

while True:
    user_input = input("You: ").strip()

    if user_input.lower() in ['exit', 'quit', 'bye']:
        print("\nGoodbye!")
        break

    if not user_input:
        continue

    conversation_history.append({"role": "user", "content": user_input})
    print("\nAgent is thinking...\n")

    response = await agent.ainvoke({"messages": conversation_history})
    conversation_history = response['messages']
    final_response = response['messages'][-1].content
    print(f"Agent: {final_response}\n")
What's happening:
  • We initialize an empty conversation_history list to maintain context across interactions
  • A while loop continuously accepts user input from the command line
  • When a user types a message, it's added to the conversation history and sent to the agent
  • The agent processes the request using the ainvoke() method with the full conversation history
  • Users can type 'exit', 'quit', or 'bye' to end the chat session gracefully

Run the application

if __name__ == "__main__":
    asyncio.run(main())
What's happening:
  • We call the main() function using asyncio.run() to start the application

Complete Code

Here's the complete code to get you started with Notion and LangChain:

from langchain_mcp_adapters.client import MultiServerMCPClient
from langchain.agents import create_agent
from dotenv import load_dotenv
from composio import Composio
import asyncio
import os

load_dotenv()

async def main():
    composio = Composio(api_key=os.getenv("COMPOSIO_API_KEY"))
    
    if not os.getenv("COMPOSIO_API_KEY"):
        raise ValueError("COMPOSIO_API_KEY is not set")
    if not os.getenv("COMPOSIO_USER_ID"):
        raise ValueError("COMPOSIO_USER_ID is not set")
    
    session = composio.create(
        user_id=os.getenv("COMPOSIO_USER_ID"),
        toolkits=['notion']
    )

    url = session.mcp.url
    
    client = MultiServerMCPClient({
        "notion-agent": {
            "transport": "streamable_http",
            "url": url,
            "headers": {
                "x-api-key": os.getenv("COMPOSIO_API_KEY")
            }
        }
    })
    
    tools = await client.get_tools()
  
    agent = create_agent("gpt-5", tools)
    
    conversation_history = []
    
    print("Chat started! Type 'exit' or 'quit' to end the conversation.\n")
    print("Ask any Notion related question or task to the agent.\n")
    
    while True:
        user_input = input("You: ").strip()
        
        if user_input.lower() in ['exit', 'quit', 'bye']:
            print("\nGoodbye!")
            break
        
        if not user_input:
            continue
        
        conversation_history.append({"role": "user", "content": user_input})
        print("\nAgent is thinking...\n")
        
        response = await agent.ainvoke({"messages": conversation_history})
        conversation_history = response['messages']
        final_response = response['messages'][-1].content
        print(f"Agent: {final_response}\n")

if __name__ == "__main__":
    asyncio.run(main())

Conclusion

You've successfully built a LangChain agent that can interact with Notion through Composio's Tool Router.

Key features of this implementation:

  • Dynamic tool loading through Composio's Tool Router
  • Conversation history maintenance for context-aware responses
  • Async Python provides clean, efficient execution of agent workflows
You can extend this further by adding error handling, implementing specific business logic, or integrating additional Composio toolkits to create multi-app workflows.

How to build Notion MCP Agent with another framework

OpenAI Agents SDK

OpenAI Agents SDK

Use Notion MCP with OpenAI Agents SDK

Claude Agent SDK

Claude Agent SDK

Use Notion MCP with Claude Agent SDK

Google ADK

Google ADK

Use Notion MCP with Google ADK

Vercel AI SDK

Vercel AI SDK

Use Notion MCP with Vercel AI SDK

Mastra AI

Mastra AI

Use Notion MCP with Mastra AI

LlamaIndex

LlamaIndex

Use Notion MCP with LlamaIndex

CrewAI

CrewAI

Use Notion MCP with CrewAI

FAQ

What are the differences in Tool Router MCP and Notion MCP?

With a standalone Notion MCP server, the agents and LLMs can only access a fixed set of Notion tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Notion and many other apps based on the task at hand, all through a single MCP endpoint.

Can I use Tool Router MCP with LangChain?

Yes, you can. LangChain 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 Notion tools.

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

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

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