Gmail Auto-Reply Workflow: GPT-4o, Dumpling AI & LangChain Agent

Automatically reply to Gmail enquiries with an AI-powered LangChain agent

This Gmail Auto-Reply Workflow watches your inbox, detects real customer enquiries, analyzes the message with GPT-4o and a LangChain Agent, retrieves relevant context via Dumpling AI, and then sends a personalized response back through Gmail—saving you time on repetitive email support and sales questions.

What this workflow does

• Listens for new incoming Gmail messages using the Gmail Trigger node.
• Classifies whether the email is an enquiry with a GPT-4o classification prompt.
• Filters intelligently: continues only when the message is classified as an enquiry (using a Filter node).
• Analyzes the email content with a LangChain Agent that includes memory and AI tools.
• Fetches helpful context using Dumpling AI to support a more relevant reply.
• Sends a personalized response to the original sender via Gmail—all within minutes.

Use cases

• Customer support teams handling frequent “How do I…?” and “Can you help with…” requests.
• Sales departments quickly responding to inbound leads and enquiry-style messages.
• Solopreneurs who want faster replies to common questions without writing the same messages repeatedly.

Technical details

• Gmail Trigger to detect new emails (requires Gmail OAuth2 authentication).
• GPT-4o for enquiry classification.
• Filter node to proceed only for enquiry messages.
• n8nn8n-nodes-langchainagent and n8nn8n-nodes-langchainopen ai for the LangChain Agent with AI tools and memory.
• Dumpling AI agent enhancement to retrieve relevant information before drafting a reply.
• Gmail tool to send the generated auto-reply.

If you’re looking for an n8n automation workflow that accelerates email response for enquiries, this GPT-4o + LangChain + Dumpling AI solution is built specifically for that job.