Content
# m365-actions-mcp-server
MCP server that adds **write operations** and **shared mailbox search** to Microsoft 365 — the missing piece that turns Anthropic's read-only ms365 connector into a full bidirectional integration.
## Why this exists
Anthropic's built-in Microsoft 365 connector gives Claude powerful read access: searching emails, browsing calendars, finding Teams messages, querying SharePoint. But it **cannot send, create, update, or delete anything**, and it has **limited support for shared/delegated mailboxes**. This server fills both gaps.
With both connectors running side by side, Claude can complete full workflows end-to-end: read an email and reply to it, check calendar availability and book a meeting, find a Teams conversation and respond — all without leaving the chat.
## Available Tools
### Email
| Tool | Description | Works with |
|------|-------------|------------|
| `m365_send_mail` | Send a new email | — |
| `m365_reply_mail` | Reply to an existing email (reply / reply-all) | `outlook_email_search` (Anthropic) to get message ID |
| `m365_get_attachments` | Download attachments from an email | `outlook_email_search` (Anthropic) to get message ID |
| `m365_search_shared_mail` | Search emails in shared/delegated mailboxes | Standalone, uses Graph API /users/{mailbox}/messages with KQL search |
### Calendar
| Tool | Description | Works with |
|------|-------------|------------|
| `m365_create_event` | Create a calendar event (with optional Teams link) | `find_meeting_availability` (Anthropic) to check slots |
| `m365_update_event` | Update an existing event | `outlook_calendar_search` (Anthropic) to get event ID |
| `m365_delete_event` | Delete an event | `outlook_calendar_search` (Anthropic) to get event ID |
### Teams
| Tool | Description | Works with |
|------|-------------|------------|
| `m365_list_teams_and_channels` | List joined teams and their channels | — |
| `m365_send_channel_message` | Send a message to a Teams channel | `m365_list_teams_and_channels` to get IDs |
| `m365_send_chat_message` | Send a message in a Teams chat (1:1 or group) | `chat_message_search` (Anthropic) to get chat ID |
| `m365_reply_to_message` | Reply to an existing Teams message | `chat_message_search` (Anthropic) to get message ID |
## How it works with the Anthropic connector
```
Anthropic ms365 connector (read) m365-actions-mcp-server (write)
───────────────────────────────── ──────────────────────────────────
outlook_email_search ──→ m365_send_mail / m365_reply_mail
outlook_calendar_search ──→ m365_create_event / m365_update_event
find_meeting_availability ──→ m365_create_event
chat_message_search ──→ m365_send_chat_message / m365_reply_to_message
sharepoint_search ──→ (read-only, no write needed)
```
Claude automatically chains these tools together. For example: "Find the email from Marco about the invoice and reply saying we'll pay by Friday" triggers `outlook_email_search` (Anthropic) followed by `m365_reply_mail` (this server).
## Shared Mailbox Search
The m365_search_shared_mail tool fills a gap in the Anthropic connector: reliable search across shared/delegated mailboxes. It accesses /users/{mailbox}/messages directly via Microsoft Graph API, supporting:
- **KQL search** (from:, subject:, free text) via the search parameter
- **Date range filtering** via OData filter
- **Pagination fallback** with client-side filtering when search is unavailable
- **Folder targeting** (Inbox, Sent Items, etc.)
This is needed because the Anthropic connector outlook_email_search has unreliable indexing for shared mailboxes, and may miss emails in high-volume mailboxes.
The Mail.Read.Shared delegated permission must be granted in Azure AD for this tool to work.
## Prerequisites
- Node.js >= 18
- An app registered on Azure AD / Entra ID
### Azure App Configuration
1. Go to [Entra ID](https://portal.azure.com) -> App registrations -> New registration
2. Name: `M365 Actions MCP Server`
3. Supported account types: **Single tenant**
4. Redirect URI: platform **Web**, URI `http://localhost:3939/auth/callback`
5. Create a **Client Secret** (Certificates & secrets -> New client secret)
6. Add **Delegated** permissions (API permissions -> Microsoft Graph):
- `Mail.Send`
- `Mail.Read`
- `Mail.Read.Shared`
- `Calendars.ReadWrite`
- `Chat.ReadWrite`
- `ChannelMessage.Send`
- `Team.ReadBasic.All`
- `Channel.ReadBasic.All`
- `User.Read`
- `offline_access`
7. Click **Grant admin consent**
## Installation
```bash
git clone https://github.com/dfsolutions/m365-actions-mcp-server.git
cd m365-actions-mcp-server
npm install
```
## Configuration
Copy `.env.example` to `.env` and fill in your Azure app credentials:
```bash
cp .env.example .env
```
```env
M365_CLIENT_ID=your-client-id
M365_CLIENT_SECRET=your-client-secret
M365_TENANT_ID=your-tenant-id
M365_REDIRECT_URI=http://localhost:3939/auth/callback
M365_USER_EMAIL=your-email@domain.com
```
## Build and Run
```bash
npx tsc
node dist/index.js
```
On the first run, the browser will open for Microsoft login. The token is cached in `~/.m365-actions-tokens.json` and reused automatically.
## Integration with Claude Desktop / Cowork
Add to your MCP configuration file:
```json
{
"mcpServers": {
"m365-actions": {
"command": "node",
"args": ["/full/path/to/m365-actions-mcp-server/dist/index.js"],
"env": {
"M365_CLIENT_ID": "your-client-id",
"M365_CLIENT_SECRET": "your-client-secret",
"M365_TENANT_ID": "your-tenant-id",
"M365_REDIRECT_URI": "http://localhost:3939/auth/callback",
"M365_USER_EMAIL": "your-email@domain.com"
}
}
}
}
```
Alternatively, if the variables are in the `.env` file inside the project folder:
```json
{
"mcpServers": {
"m365-actions": {
"command": "node",
"args": ["/full/path/to/m365-actions-mcp-server/dist/index.js"]
}
}
}
```
## Authentication
The server uses MSAL with the **Authorization Code (delegated)** flow:
- On first run, it opens the browser for login
- Saves access + refresh token in `~/.m365-actions-tokens.json`
- Automatically renews the token on expiry
- The refresh token lasts ~90 days, then a new login is required
## License
MIT
