How to integrate Outlook MCP with LlamaIndex

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Introduction

This guide walks you through connecting Outlook to LlamaIndex using the Composio tool router. By the end, you'll have a working Outlook agent that can download latest attachments from my inbox, create new calendar for project deadlines, add rule to move newsletters to folder, get my current automatic reply settings through natural language commands.

This guide will help you understand how to give your LlamaIndex agent real control over a Outlook account through Composio's Outlook 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:
  • Set your OpenAI and Composio API keys
  • Install LlamaIndex and Composio packages
  • Create a Composio Tool Router session for Outlook
  • Connect LlamaIndex to the Outlook MCP server
  • Build a Outlook-powered agent using LlamaIndex
  • Interact with Outlook through natural language

What is LlamaIndex?

LlamaIndex is a data framework for building LLM applications. It provides tools for connecting LLMs to external data sources and services through agents and tools.

Key features include:

  • ReAct Agent: Reasoning and acting pattern for tool-using agents
  • MCP Tools: Native support for Model Context Protocol
  • Context Management: Maintain conversation context across interactions
  • Async Support: Built for async/await patterns

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

The Outlook MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Outlook account. It provides structured and secure access to your email, calendar, and contacts, so your agent can perform actions like sending emails, organizing folders, managing your calendar, and handling attachments on your behalf.

  • Email organization and folder management: Let your agent create, delete, or organize mail folders to keep your inbox tidy and efficient.
  • Calendar and event creation: Easily have your agent set up new calendars, so you can organize meetings and events without lifting a finger.
  • Smart attachments handling: Automatically download files from your emails or add attachments to outgoing messages for seamless file management.
  • Automated rules and filtering: Direct your agent to create email rules that filter, sort, or take action on messages as they arrive.
  • Contact and category organization: Ask your agent to create new contact folders or master categories to streamline how you manage people and projects.

Supported Tools & Triggers

Tools
Triggers
Add mail attachmentTool to add an attachment to an email message.
Create calendarTool to create a new calendar in the signed-in user's mailbox.
Create contact folderTool to create a new contact folder in the user's mailbox.
Create Email RuleCreate email rule filter with conditions and actions
Create mail folderTool to create a new mail folder.
Create master categoryTool to create a new category in the user's master category list.
Delete mail folderDelete a mail folder from the user's mailbox.
Download Outlook attachmentDownloads a specific file attachment from an email message in a microsoft outlook mailbox; the attachment must contain 'contentbytes' (binary data) and not be a link or embedded item.
Get mailbox settingsTool to retrieve mailbox settings.
Get mail deltaTool to retrieve incremental changes (delta) of messages in a mailbox.
Get mail tipsTool to retrieve mail tips such as automatic replies and mailbox full status.
Get master categoriesTool to retrieve the user's master category list.
Get supported languagesTool to retrieve supported languages in the user's mailbox.
Get supported time zonesTool to retrieve supported time zones in the user's mailbox.
List Outlook calendarsTool to list calendars in the signed-in user's mailbox.
List event attachmentsTool to list attachments for a specific outlook calendar event.
List Outlook attachmentsLists metadata (like name, size, and type, but not `contentbytes`) for all attachments of a specified outlook email message.
List event remindersTool to retrieve reminders for events occurring within a specified time range.
Add event attachmentAdds an attachment to a specific outlook calendar event.
Create Calendar EventCreates a new outlook calendar event, ensuring `start datetime` is chronologically before `end datetime`.
Create contactCreates a new contact in a microsoft outlook user's contacts folder.
Create email draftCreates an outlook email draft with subject, body, recipients, and an optional attachment.
Create a draft replyCreates a draft reply in the specified user's outlook mailbox to an existing message (identified by a valid `message id`), optionally including a `comment` and cc/bcc recipients.
Delete ContactPermanently deletes an existing contact, using its `contact id` (obtainable via 'list user contacts' or 'get contact'), from the outlook contacts of the user specified by `user id`.
Delete Calendar EventDeletes an existing calendar event, identified by its unique `event id`, from a specified user's microsoft outlook calendar, with an option to send cancellation notifications to attendees.
Get contactRetrieves a specific outlook contact by its `contact id` from the contacts of a specified `user id` (defaults to 'me' for the authenticated user).
Get contact foldersTool to retrieve a list of contact folders in the signed-in user's mailbox.
Get calendar eventRetrieves the full details of a specific calendar event by its id from a user's outlook calendar, provided the event exists.
Get email messageRetrieves a specific email message by its id from the specified user's outlook mailbox.
Get Outlook profileRetrieves the microsoft outlook profile for a specified user.
Get scheduleRetrieves free/busy schedule information for specified email addresses within a defined time window.
List Outlook contactsRetrieves a user's microsoft outlook contacts, from the default or a specified contact folder.
List eventsRetrieves events from a user's outlook calendar via microsoft graph api, supporting pagination, filtering, property selection, sorting, and timezone specification.
List mail foldersTool to list a user's top-level mail folders.
List MessagesRetrieves a list of email messages from a specified mail folder in an outlook mailbox, with options for filtering (including by conversationid to get all messages in a thread), pagination, and sorting; ensure 'user id' and 'folder' are valid, and all date/time strings are in iso 8601 format.
Move message to folderMove a message to another folder within the specified user's mailbox.
Reply to EmailSends a plain text reply to an outlook email message, identified by `message id`, allowing optional cc and bcc recipients.
Search Outlook messagesSearches messages in a microsoft 365 or enterprise outlook account mailbox, supporting filters for sender, subject, attachments, pagination, and sorting by relevance or date.
Send emailSends an email with subject, body, recipients, and an optional attachment via microsoft graph api; attachments require a non-empty file with valid name and mimetype.
Update calendar eventUpdates specified fields of an existing outlook calendar event.
Update ContactUpdates an existing outlook contact, identified by `contact id` for the specified `user id`, requiring at least one other field to be modified.
Update email messageUpdates specified properties of an existing email message; `message id` must identify a valid message within the specified `user id`'s mailbox.
Update mailbox settingsTool to update mailbox settings for the signed-in user.

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 you begin, make sure you have:
  • Python 3.8/Node 16 or higher installed
  • A Composio account with the API key
  • An OpenAI API key
  • A Outlook account and project
  • Basic familiarity with async Python/Typescript

Getting API Keys for OpenAI, Composio, and Outlook

OpenAI API key (OPENAI_API_KEY)
  • Go to the OpenAI dashboard
  • Create an API key if you don't have one
  • Assign it to OPENAI_API_KEY in .env
Composio API key and user ID
  • Log into the Composio dashboard
  • Copy your API key from Settings
    • Use this as COMPOSIO_API_KEY
  • Pick a stable user identifier (email or ID)
    • Use this as COMPOSIO_USER_ID

Installing dependencies

pip install composio-llamaindex llama-index llama-index-llms-openai llama-index-tools-mcp python-dotenv

Create a new Python project and install the necessary dependencies:

  • composio-llamaindex: Composio's LlamaIndex integration
  • llama-index: Core LlamaIndex framework
  • llama-index-llms-openai: OpenAI LLM integration
  • llama-index-tools-mcp: MCP client for LlamaIndex
  • python-dotenv: Environment variable management

Set environment variables

bash
OPENAI_API_KEY=your-openai-api-key
COMPOSIO_API_KEY=your-composio-api-key
COMPOSIO_USER_ID=your-user-id

Create a .env file in your project root:

These credentials will be used to:

  • Authenticate with OpenAI's GPT-5 model
  • Connect to Composio's Tool Router
  • Identify your Composio user session for Outlook access

Import modules

import asyncio
import os
import dotenv

from composio import Composio
from composio_llamaindex import LlamaIndexProvider
from llama_index.core.agent.workflow import ReActAgent
from llama_index.core.workflow import Context
from llama_index.llms.openai import OpenAI
from llama_index.tools.mcp import BasicMCPClient, McpToolSpec

dotenv.load_dotenv()

Create a new file called outlook_llamaindex_agent.py and import the required modules:

Key imports:

  • asyncio: For async/await support
  • Composio: Main client for Composio services
  • LlamaIndexProvider: Adapts Composio tools for LlamaIndex
  • ReActAgent: LlamaIndex's reasoning and action agent
  • BasicMCPClient: Connects to MCP endpoints
  • McpToolSpec: Converts MCP tools to LlamaIndex format

Load environment variables and initialize Composio

OPENAI_API_KEY = os.getenv("OPENAI_API_KEY")
COMPOSIO_API_KEY = os.getenv("COMPOSIO_API_KEY")
COMPOSIO_USER_ID = os.getenv("COMPOSIO_USER_ID")

if not OPENAI_API_KEY:
    raise ValueError("OPENAI_API_KEY is not set in the environment")
if not COMPOSIO_API_KEY:
    raise ValueError("COMPOSIO_API_KEY is not set in the environment")
if not COMPOSIO_USER_ID:
    raise ValueError("COMPOSIO_USER_ID is not set in the environment")

What's happening:

This ensures missing credentials cause early, clear errors before the agent attempts to initialise.

Create a Tool Router session and build the agent function

async def build_agent() -> ReActAgent:
    composio_client = Composio(
        api_key=COMPOSIO_API_KEY,
        provider=LlamaIndexProvider(),
    )

    session = composio_client.create(
        user_id=COMPOSIO_USER_ID,
        toolkits=["outlook"],
    )

    mcp_url = session.mcp.url
    print(f"Composio MCP URL: {mcp_url}")

    mcp_client = BasicMCPClient(mcp_url, headers={"x-api-key": COMPOSIO_API_KEY})
    mcp_tool_spec = McpToolSpec(client=mcp_client)
    tools = await mcp_tool_spec.to_tool_list_async()

    llm = OpenAI(model="gpt-5")

    description = "An agent that uses Composio Tool Router MCP tools to perform Outlook actions."
    system_prompt = """
    You are a helpful assistant connected to Composio Tool Router.
    Use the available tools to answer user queries and perform Outlook actions.
    """
    return ReActAgent(tools=tools, llm=llm, description=description, system_prompt=system_prompt, verbose=True)

What's happening here:

  • We create a Composio client using your API key and configure it with the LlamaIndex provider
  • We then create a tool router MCP session for your user, specifying the toolkits we want to use (in this case, outlook)
  • The session returns an MCP HTTP endpoint URL that acts as a gateway to all your configured tools
  • LlamaIndex will connect to this endpoint to dynamically discover and use the available Outlook tools.
  • The MCP tools are mapped to LlamaIndex-compatible tools and plug them into the Agent.

Create an interactive chat loop

async def chat_loop(agent: ReActAgent) -> None:
    ctx = Context(agent)
    print("Type 'quit', 'exit', or Ctrl+C to stop.")

    while True:
        try:
            user_input = input("\nYou: ").strip()
        except (KeyboardInterrupt, EOFError):
            print("\nBye!")
            break

        if not user_input or user_input.lower() in {"quit", "exit"}:
            print("Bye!")
            break

        try:
            print("Agent: ", end="", flush=True)
            handler = agent.run(user_input, ctx=ctx)

            async for event in handler.stream_events():
                # Stream token-by-token from LLM responses
                if hasattr(event, "delta") and event.delta:
                    print(event.delta, end="", flush=True)
                # Show tool calls as they happen
                elif hasattr(event, "tool_name"):
                    print(f"\n[Using tool: {event.tool_name}]", flush=True)

            # Get final response
            response = await handler
            print()  # Newline after streaming
        except KeyboardInterrupt:
            print("\n[Interrupted]")
            continue
        except Exception as e:
            print(f"\nError: {e}")

What's happening here:

  • We're creating a direct terminal interface to chat with your Outlook database
  • The LLM's responses are streamed to the CLI for faster interaction.
  • The agent uses context to maintain conversation history
  • You can type 'quit' or 'exit' to stop the chat loop gracefully
  • Agent responses and any errors are displayed in a clear, readable format

Define the main entry point

async def main() -> None:
    agent = await build_agent()
    await chat_loop(agent)

if __name__ == "__main__":
    # Handle Ctrl+C gracefully
    signal.signal(signal.SIGINT, lambda s, f: (print("\nBye!"), exit(0)))
    try:
        asyncio.run(main())
    except KeyboardInterrupt:
        print("\nBye!")

What's happening here:

  • We're orchestrating the entire application flow
  • The agent gets built with proper error handling
  • Then we kick off the interactive chat loop so you can start talking to Outlook

Run the agent

npx ts-node llamaindex-agent.ts

When prompted, authenticate and authorise your agent with Outlook, then start asking questions.

Complete Code

Here's the complete code to get you started with Outlook and LlamaIndex:

import asyncio
import os
import signal
import dotenv

from composio import Composio
from composio_llamaindex import LlamaIndexProvider
from llama_index.core.agent.workflow import ReActAgent
from llama_index.core.workflow import Context
from llama_index.llms.openai import OpenAI
from llama_index.tools.mcp import BasicMCPClient, McpToolSpec

dotenv.load_dotenv()

OPENAI_API_KEY = os.getenv("OPENAI_API_KEY")
COMPOSIO_API_KEY = os.getenv("COMPOSIO_API_KEY")
COMPOSIO_USER_ID = os.getenv("COMPOSIO_USER_ID")

if not OPENAI_API_KEY:
    raise ValueError("OPENAI_API_KEY is not set")
if not COMPOSIO_API_KEY:
    raise ValueError("COMPOSIO_API_KEY is not set")
if not COMPOSIO_USER_ID:
    raise ValueError("COMPOSIO_USER_ID is not set")

async def build_agent() -> ReActAgent:
    composio_client = Composio(
        api_key=COMPOSIO_API_KEY,
        provider=LlamaIndexProvider(),
    )

    session = composio_client.create(
        user_id=COMPOSIO_USER_ID,
        toolkits=["outlook"],
    )

    mcp_url = session.mcp.url
    print(f"Composio MCP URL: {mcp_url}")

    mcp_client = BasicMCPClient(mcp_url, headers={"x-api-key": COMPOSIO_API_KEY})
    mcp_tool_spec = McpToolSpec(client=mcp_client)
    tools = await mcp_tool_spec.to_tool_list_async()

    llm = OpenAI(model="gpt-5")
    description = "An agent that uses Composio Tool Router MCP tools to perform Outlook actions."
    system_prompt = """
    You are a helpful assistant connected to Composio Tool Router.
    Use the available tools to answer user queries and perform Outlook actions.
    """
    return ReActAgent(
        tools=tools,
        llm=llm,
        description=description,
        system_prompt=system_prompt,
        verbose=True,
    );

async def chat_loop(agent: ReActAgent) -> None:
    ctx = Context(agent)
    print("Type 'quit', 'exit', or Ctrl+C to stop.")

    while True:
        try:
            user_input = input("\nYou: ").strip()
        except (KeyboardInterrupt, EOFError):
            print("\nBye!")
            break

        if not user_input or user_input.lower() in {"quit", "exit"}:
            print("Bye!")
            break

        try:
            print("Agent: ", end="", flush=True)
            handler = agent.run(user_input, ctx=ctx)

            async for event in handler.stream_events():
                # Stream token-by-token from LLM responses
                if hasattr(event, "delta") and event.delta:
                    print(event.delta, end="", flush=True)
                # Show tool calls as they happen
                elif hasattr(event, "tool_name"):
                    print(f"\n[Using tool: {event.tool_name}]", flush=True)

            # Get final response
            response = await handler
            print()  # Newline after streaming
        except KeyboardInterrupt:
            print("\n[Interrupted]")
            continue
        except Exception as e:
            print(f"\nError: {e}")

async def main() -> None:
    agent = await build_agent()
    await chat_loop(agent)

if __name__ == "__main__":
    # Handle Ctrl+C gracefully
    signal.signal(signal.SIGINT, lambda s, f: (print("\nBye!"), exit(0)))
    try:
        asyncio.run(main())
    except KeyboardInterrupt:
        print("\nBye!")

Conclusion

You've successfully connected Outlook to LlamaIndex through Composio's Tool Router MCP layer. Key takeaways:
  • Tool Router dynamically exposes Outlook tools through an MCP endpoint
  • LlamaIndex's ReActAgent handles reasoning and orchestration; Composio handles integrations
  • The agent becomes more capable without increasing prompt size
  • Async Python provides clean, efficient execution of agent workflows
You can easily extend this to other toolkits like Gmail, Notion, Stripe, GitHub, and more by adding them to the toolkits parameter.

How to build Outlook MCP Agent with another framework

OpenAI Agents SDK

OpenAI Agents SDK

Use Outlook MCP with OpenAI Agents SDK

Claude Agent SDK

Claude Agent SDK

Use Outlook MCP with Claude Agent SDK

Google ADK

Google ADK

Use Outlook MCP with Google ADK

LangChain

LangChain

Use Outlook MCP with LangChain

Vercel AI SDK

Vercel AI SDK

Use Outlook MCP with Vercel AI SDK

Mastra AI

Mastra AI

Use Outlook MCP with Mastra AI

CrewAI

CrewAI

Use Outlook MCP with CrewAI

FAQ

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

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

Can I use Tool Router MCP with LlamaIndex?

Yes, you can. LlamaIndex 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 Outlook tools.

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

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

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Context
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Letta
glean
HubSpot
Agent.ai
Altera
DataStax
Entelligence
Rolai
Context
ASU
Letta
glean
HubSpot
Agent.ai
Altera
DataStax
Entelligence
Rolai

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