outlook-mcp/email/attachments.js

Comprehensive MCP server for Claude to access Microsoft Outlook and Teams via Microsoft Graph API - including Email, Calendar, Contacts, Tasks, Teams, Chats, and Online Meetings

/**
 * Email attachments functionality
 */
const { callGraphAPI } = require('../utils/graph-api');
const { ensureAuthenticated } = require('../auth');

/**
 * List email attachments handler
 * @param {object} args - Tool arguments
 * @returns {object} - MCP response
 */
async function handleListAttachments(args) {
  try {
    const { emailId } = args;
    
    if (!emailId) {
      return {
        error: {
          code: -32602,
          message: "Email ID is required"
        }
      };
    }
    
    // Ensure user is authenticated
    const accessToken = await ensureAuthenticated();
    
    // Build the API path
    const apiPath = `me/messages/${emailId}/attachments`;
    
    // Build query parameters
    const queryParams = {
      '$select': 'id,name,size,contentType,isInline,lastModifiedDateTime'
    };
    
    console.error(`Fetching attachments for email: ${emailId}`);
    
    // Make API call
    const response = await callGraphAPI(accessToken, 'GET', apiPath, null, queryParams);
    
    const attachments = response.value || [];
    
    // Format file size
    const formatSize = (bytes) => {
      if (bytes === 0) return '0 B';
      const k = 1024;
      const sizes = ['B', 'KB', 'MB', 'GB'];
      const i = Math.floor(Math.log(bytes) / Math.log(k));
      return parseFloat((bytes / Math.pow(k, i)).toFixed(2)) + ' ' + sizes[i];
    };
    
    return {
      content: [
        {
          type: "text",
          text: `Found ${attachments.length} attachments:\n\n${attachments.map(attachment => {
            const inline = attachment.isInline ? ' (Inline)' : '';
            const modified = attachment.lastModifiedDateTime ? 
              new Date(attachment.lastModifiedDateTime).toLocaleString() : 'Unknown';
            
            return `📎 ${attachment.name}${inline}
   ID: ${attachment.id}
   Size: ${formatSize(attachment.size)}
   Type: ${attachment.contentType}
   Modified: ${modified}`;
          }).join('\n\n')}`
        }
      ]
    };
  } catch (error) {
    console.error('Error in handleListAttachments:', error);
    return {
      error: {
        code: -32603,
        message: `Failed to list attachments: ${error.message}`
      }
    };
  }
}

/**
 * Download email attachment handler
 * @param {object} args - Tool arguments
 * @returns {object} - MCP response
 */
async function handleDownloadAttachment(args) {
  try {
    const { emailId, attachmentId } = args;
    
    if (!emailId || !attachmentId) {
      return {
        error: {
          code: -32602,
          message: "Email ID and attachment ID are required"
        }
      };
    }
    
    // Ensure user is authenticated
    const accessToken = await ensureAuthenticated();
    
    // Build the API path
    const apiPath = `me/messages/${emailId}/attachments/${attachmentId}`;
    
    // Build query parameters - get full attachment data
    const queryParams = {
      '$select': 'id,name,size,contentType,contentBytes,isInline'
    };
    
    console.error(`Downloading attachment: ${attachmentId} from email: ${emailId}`);
    
    // Make API call
    const attachment = await callGraphAPI(accessToken, 'GET', apiPath, null, queryParams);
    
    // Format file size
    const formatSize = (bytes) => {
      if (bytes === 0) return '0 B';
      const k = 1024;
      const sizes = ['B', 'KB', 'MB', 'GB'];
      const i = Math.floor(Math.log(bytes) / Math.log(k));
      return parseFloat((bytes / Math.pow(k, i)).toFixed(2)) + ' ' + sizes[i];
    };
    
    return {
      content: [
        {
          type: "text",
          text: `✅ Attachment downloaded successfully!

**File Name:** ${attachment.name}
**Size:** ${formatSize(attachment.size)}
**Type:** ${attachment.contentType}
**Content:** The attachment content is available in base64 format.

**Base64 Content:**
${attachment.contentBytes}

You can decode this base64 content to save the file locally.`
        }
      ]
    };
  } catch (error) {
    console.error('Error in handleDownloadAttachment:', error);
    return {
      error: {
        code: -32603,
        message: `Failed to download attachment: ${error.message}`
      }
    };
  }
}

module.exports = {
  handleListAttachments,
  handleDownloadAttachment
};