Gmail DOCX Generator with OpenAI, Sheets & Drive | n8n Workflow

Turn Gmail requests into ready-to-send DOCX files—automatically

This n8n workflow listens for new emails in Gmail, matches the request to the correct DOCX template stored in Google Drive (using OpenAI + a Google Sheets template catalog), generates a filled DOCX via a Pandoc HTTP conversion service, uploads it back to Google Drive, and replies in the same email thread with the attachment and a Drive link.

What this workflow does

• Triggers on new Gmail messages and extracts the sender, subject, and body text.
• Validates authorization by checking allowed sender domains and a required keyword.
• Loads a template catalog from Google Sheets (Title, Aliases, FileId, FileName) and formats it into a searchable list for AI matching.
• Uses OpenAI to select the best matching template and extracts recipient details and other fields. If no template fits, it replies with an “unable to match” message.
• Downloads the DOCX template from Google Drive and uses OpenAI to reproduce it as filled GitHub-flavored Markdown.
• Converts Markdown to DOCX by sending the Markdown to a Pandoc conversion HTTP endpoint.
• Uploads the generated DOCX to Google Drive and replies via Gmail in the original thread with the document attached and a Drive link.

Use cases

• Generating personalized contracts, letters, or proposals when a client emails a structured request.
• Producing standard onboarding or HR documents based on a keyword + sender authorization.
• SaaS ops teams automating document fulfillment without manually selecting templates.

Technical details

• n8n integrations: Gmail trigger + Gmail reply actions, Google Sheets, Google Drive, OpenAI, and a Pandoc HTTP conversion endpoint.
• Workflow logic nodes: if, set, code, no op, plus sticky note for documentation.
• Setup requirements: Gmail OAuth2 (trigger + replies), Google Sheets/Drive OAuth2 and a template catalog sheet, OpenAI credentials for the two OpenAI steps, and a configured Pandoc HTTP endpoint.