M365 Assistant MCP Server

A comprehensive MCP (Model Context Protocol) server that connects Claude with Microsoft 365 services through the Microsoft Graph API and Power Automate API.

Supported Services

• Outlook - Email, calendar, folders, and rules
• OneDrive - Files, folders, search, and sharing
• Power Automate - Flows, environments, and run history

Directory Structure

├── index.js                 # Main entry point
├── config.js                # Configuration settings
├── auth/                    # Authentication modules
│   ├── index.js             # Authentication exports
│   ├── token-manager.js     # Token storage and refresh (Graph + Flow)
│   └── tools.js             # Auth-related tools
├── calendar/                # Calendar functionality
│   ├── index.js             # Calendar exports
│   ├── list.js              # List events
│   ├── create.js            # Create event
│   ├── delete.js            # Delete event
│   ├── cancel.js            # Cancel event
│   ├── accept.js            # Accept event
│   └── decline.js           # Decline event
├── email/                   # Email functionality
│   ├── index.js             # Email exports
│   ├── list.js              # List emails
│   ├── search.js            # Search emails
│   ├── read.js              # Read email
│   ├── send.js              # Send email
│   └── mark-as-read.js      # Mark email read/unread
├── folder/                  # Folder functionality
│   ├── index.js             # Folder exports
│   ├── list.js              # List folders
│   ├── create.js            # Create folder
│   └── move.js              # Move emails
├── rules/                   # Email rules functionality
│   ├── index.js             # Rules exports
│   ├── list.js              # List rules
│   └── create.js            # Create rule
├── onedrive/                # OneDrive functionality
│   ├── index.js             # OneDrive exports
│   ├── list.js              # List files/folders
│   ├── search.js            # Search files
│   ├── download.js          # Get download URL
│   ├── upload.js            # Simple upload (<4MB)
│   ├── upload-large.js      # Chunked upload (>4MB)
│   ├── share.js             # Create sharing link
│   └── folder.js            # Create/delete folders
├── power-automate/          # Power Automate functionality
│   ├── index.js             # Power Automate exports
│   ├── flow-api.js          # Flow API client
│   ├── list-environments.js # List environments
│   ├── list-flows.js        # List flows
│   ├── run-flow.js          # Trigger flow
│   ├── list-runs.js         # Run history
│   └── toggle-flow.js       # Enable/disable flow
└── utils/                   # Utility functions
    ├── graph-api.js         # Microsoft Graph API helper
    ├── odata-helpers.js     # OData query building
    └── mock-data.js         # Test mode data

Features

• Authentication: OAuth 2.0 authentication with Microsoft Graph API (+ Flow API for Power Automate)
• Email Management: List, search, read, send, and organize emails
• Calendar Management: List, create, accept, decline, and delete calendar events
• OneDrive Integration: List, search, upload, download, and share files
• Power Automate: List environments/flows, trigger flows, view run history
• Modular Structure: Clean separation of concerns for maintainability
• Test Mode: Simulated responses for testing without real API calls

Available Tools

Outlook (Email & Calendar)

OneDrive

Power Automate

Quick Start

1. Install dependencies: npm install
2. Azure setup: Register app in Azure Portal (see detailed steps below)
3. Configure environment: Copy .env.example to .env and add your Azure credentials
4. Configure Claude: Update your Claude Desktop config with the server path
5. Start auth server: npm run auth-server
6. Authenticate: Use the authenticate tool in Claude to get the OAuth URL
7. Start using: Access your M365 data through Claude!

Installation

Prerequisites

• Node.js 14.0.0 or higher
• npm or yarn package manager
• Azure account for app registration

Install Dependencies

npm install

Azure App Registration & Configuration

App Registration

1. Open Azure Portal
2. Search for "App registrations"
3. Click "New registration"
4. Name: "M365 MCP Server"
5. Account type: "Accounts in any organizational directory and personal Microsoft accounts"
6. Redirect URI: Web → http://localhost:3333/auth/callback
7. Click "Register"
8. Copy the "Application (client) ID" for your .env file

App Permissions

1. Go to "API permissions" under Manage
2. Click "Add a permission" → "Microsoft Graph" → "Delegated permissions"
3. Add these permissions:

• offline_access
• User.Read
• Mail.Read, Mail.ReadWrite, Mail.Send
• Calendars.Read, Calendars.ReadWrite
• Files.Read, Files.ReadWrite

1. Click "Add permissions"

For Power Automate (optional):

• Requires additional Azure AD configuration with Flow API scope
• See Power Automate section below for details

Client Secret

1. Go to "Certificates & secrets" → "Client secrets"
2. Click "New client secret"
3. Add description and select expiration
4. Copy the VALUE (not the Secret ID)

Configuration

1. Environment Variables

cp .env.example .env

Edit .env:

# Get these values from Azure Portal > App Registrations > Your App
MS_CLIENT_ID=your-application-client-id-here
MS_CLIENT_SECRET=your-client-secret-VALUE-here
MS_TENANT_ID=your-tenant-id-here
USE_TEST_MODE=false

Important Notes:

• Use MS_CLIENT_ID and MS_CLIENT_SECRET in the .env file
• Set MS_TENANT_ID for single-tenant apps to avoid /common endpoint errors
• For Claude Desktop config, you'll use OUTLOOK_CLIENT_ID and OUTLOOK_CLIENT_SECRET
• Always use the client secret VALUE, never the Secret ID

2. Claude Desktop Configuration

Add to your Claude Desktop config:

{
  "mcpServers": {
    "m365-assistant": {
      "command": "node",
      "args": ["/path/to/outlook-mcp/index.js"],
      "env": {
        "USE_TEST_MODE": "false",
        "OUTLOOK_CLIENT_ID": "your-client-id",
        "OUTLOOK_CLIENT_SECRET": "your-client-secret"
      }
    }
  }
}

Authentication

Graph API (Outlook + OneDrive)

1. Start auth server: npm run auth-server
2. Use the authenticate tool in Claude
3. Visit the provided URL and sign in
4. Tokens saved to ~/.outlook-mcp-tokens.json

Power Automate (Optional)

Power Automate requires a separate token with the Flow API scope. Configure additional Azure AD permissions for https://service.flow.microsoft.com//.default scope.

Limitations:

• Only solution-aware flows are accessible
• Only manual trigger flows can be run via API
• Requires environment ID for most operations

Troubleshooting

Common Issues

"Cannot find module"

npm install

"Port 3333 in use"

npx kill-port 3333
npm run auth-server

"Invalid client secret" (AADSTS7000215)

• Use the secret VALUE, not the Secret ID

"Authentication required"

• Delete ~/.outlook-mcp-tokens.json and re-authenticate

Testing

# Run with MCP Inspector
npm run inspect

# Run in test mode (mock data)
npm run test-mode

# Run Jest tests
npm test

Extending the Server

1. Create new module directory
2. Implement tool handlers in separate files
3. Export tool definitions from module index