Dify Gmail Plugin

A comprehensive Gmail integration plugin for Dify that provides essential mail-related actions using OAuth2.0 authentication. This plugin extends beyond basic email reading to offer a complete Gmail management solution.

Features

Email Management

• Get Message Details: Retrieve detailed information about specific emails including headers, body, and attachments
• Search Messages: Advanced Gmail search using Gmail's powerful search syntax and operators

Email Composition & Sending

• Send Message: Send emails directly with recipients, subject, body, CC, BCC, and reply-to
• Create Drafts: Create draft emails that can be edited and sent later
• List Drafts: View and manage draft emails
• Send Drafts: Send previously created draft emails

Attachment Support

• Download Attachments: Download attachment content from emails
• Add Attachments: Attach files to existing draft emails

Email Organization

• Flag Messages: Mark emails for follow-up using Gmail's starring system (adds/removes 'STARRED' label)

Gmail Search Operators

The plugin supports Gmail's powerful search syntax:

• Sender/Recipient: from:example@gmail.com, to:colleague@company.com
• Subject: subject:meeting, subject:"project update"
• Date Ranges: after:2024/01/01, before:2024/12/31
• Status: is:unread, is:read, is:starred, is:important
• Attachments: has:attachment, filename:pdf
• Size: larger:10M, smaller:1M
• Labels: label:work, label:personal
• Combined: from:boss@company.com subject:meeting after:2024/01/01 has:attachment

Setup Instructions

Quick Setup Overview

1. Install the plugin from Dify Marketplace
2. Get the OAuth callback URL from the plugin's OAuth Client Settings
3. Create Google OAuth credentials with Gmail API enabled, using the Dify callback URL
4. Configure the plugin with your Client ID and Client Secret

Required OAuth Scopes

The plugin requests the following Gmail API scopes:

• https://www.googleapis.com/auth/gmail.readonly - Read emails
• https://www.googleapis.com/auth/gmail.send - Send emails
• https://www.googleapis.com/auth/gmail.compose - Create drafts
• https://www.googleapis.com/auth/gmail.modify - Modify emails (labels, flags)
• https://www.googleapis.com/auth/gmail.labels - Manage labels

Usage Examples

List Recent Inbox Messages

tool: search_messages
parameters:
  query: "in:inbox"
  max_results: 10
  include_body: false

Search for Important Emails

tool: search_messages
parameters:
  query: "is:important subject:urgent after:2024/01/01"
  max_results: 20
  include_body: true

Send an Email

tool: send_message
parameters:
  to: "recipient@example.com"
  subject: "Meeting Reminder"
  body: "Hi, this is a reminder about our meeting tomorrow."
  cc: "manager@example.com"

Create a Draft

tool: draft_message
parameters:
  to: "team@company.com"
  subject: "Weekly Update"
  body: "Here's our weekly team update..."

Flag a Message for Follow-up

tool: flag_message
parameters:
  message_id: "18c1a2b3d4e5f6g7"
  action: "flag"

Download an Attachment

# First, get message details with attachments
tool: get_message
parameters:
  message_id: "18c1a2b3d4e5f6g7"
  include_attachments: true

# Then, download the attachment using the attachment_id from above
tool: download_attachment
parameters:
  message_id: "18c1a2b3d4e5f6g7"
  attachment_id: "ANGjdJ8wXYZ..."

Tool Reference

Core Tools

Tool	Description	Key Parameters
search_messages	Advanced Gmail search	query, max_results, include_body
get_message	Get detailed message information	message_id, include_body, include_attachments

Email Composition

Tool	Description	Key Parameters
send_message	Send email immediately	to, subject, body, cc, bcc, reply_to
draft_message	Create draft email	to, subject, body, cc, bcc, reply_to
list_drafts	List draft emails	max_results, include_body
send_draft	Send draft email	draft_id

Advanced Features

Tool	Description	Key Parameters
download_attachment	Download attachment content	message_id, attachment_id
add_attachment_to_draft	Add file to draft	draft_id, file_path
flag_message	Flag/unflag for follow-up	message_id, action

Error Handling

The plugin provides comprehensive error handling:

• Authentication Errors: Clear messages when OAuth tokens expire
• API Errors: Detailed error messages from Gmail API
• Validation Errors: Parameter validation with helpful suggestions
• File Errors: Clear messages for file access and size issues

Limitations

• File Attachments: Subject to Gmail API file size limitations
• Rate Limits: Subject to Gmail API rate limits
• Authentication: Requires OAuth2.0 setup and periodic token refresh
• Search Queries: Limited to Gmail's search syntax and operators

Troubleshooting

Common Issues

1. "Access token expired": Re-authorize the plugin in Dify
2. "File not found": Ensure the file path is accessible from the plugin environment
3. "Draft not found": Verify the draft ID is valid and hasn't been deleted
4. "Permission denied": Check that all required Gmail scopes are granted

Getting Help

• Check the Gmail API documentation for detailed error codes
• Verify your OAuth2.0 credentials are correct
• Ensure the Gmail API is enabled in your Google Cloud project

Development

This plugin is built using the Dify plugin framework and follows best practices:

• Modular Design: Each tool is implemented as a separate class with clear separation of concerns
• Error Handling: Comprehensive error handling with user-friendly error messages
• Progress Updates: Real-time progress updates for operations involving multiple emails
• OAuth2.0 Integration: Secure authentication with automatic token refresh
• Gmail API Integration: Direct integration with Gmail API for optimal performance

License

This plugin is provided as-is for use with Dify. Please refer to Dify's licensing terms for usage rights.