# Rube MCP Tools Reference

## Gmail

### Send Email

Use `mcp__rube__RUBE_MULTI_EXECUTE_TOOL` to send emails via Gmail.

**Tool Call:**

```json
{
  "tools": [
    {
      "tool_slug": "GMAIL_SEND_EMAIL",
      "arguments": {
        "recipient_email": "recipient@example.com",
        "subject": "Email Subject",
        "body": "Email body content",
        "is_html": false
      }
    }
  ],
  "sync_response_to_workbench": false,
  "memory": {}
}
```

**Parameters:**

| Parameter | Type | Required | Description |
|-----------|------|----------|-------------|
| `recipient_email` | string | Yes* | Primary recipient email. Use `"me"` to send to yourself. |
| `subject` | string | Yes** | Email subject line |
| `body` | string | Yes** | Email content (plain text or HTML) |
| `is_html` | boolean | No | Set to `true` if body contains HTML (default: `false`) |
| `cc` | array | No | CC recipients: `["email1@example.com", "email2@example.com"]` |
| `bcc` | array | No | BCC recipients |
| `extra_recipients` | array | No | Additional "To" recipients |
| `attachment` | object | No | File attachment (see below) |

\* At least one of `recipient_email`, `cc`, or `bcc` must be provided.
\** At least one of `subject` or `body` must be provided.

**Attachment Format:**

```json
{
  "attachment": {
    "name": "document.pdf",
    "mimetype": "application/pdf",
    "s3key": "path/from/previous/upload"
  }
}
```

**Response:**

```json
{
  "successful": true,
  "data": {
    "id": "19bdea91fbc76cf4",
    "labelIds": ["SENT"],
    "threadId": "19bdea91fbc76cf4"
  }
}
```

**Notes:**
- The email is sent from the connected Gmail account (check connection status if unsure which account)
- HTML bodies must set `is_html: true` or recipients will see raw markup
- Gmail API limits total message size to ~25 MB after base64 encoding
