n8n AI Quote Generator: Gmail → PDF Offers with OpenAI

Turn Incoming Gmail Quote Requests into Professionally Generated PDF Offers (with OpenAI)

This n8n workflow automatically reads customer quote requests from Gmail, extracts project details using OpenAI, drafts an offer in Google Sheets, generates a German offer document as a PDF in Google Drive, and emails it back to the customer—then optionally handles supplier price inquiries from Leistungsverzeichnis requests.

What this workflow does

• Minute-by-minute Gmail intake: Every minute, it triggers when a new Gmail message matches the configured search, loading the full email content and any attachments.
• AI-assisted data extraction: Using OpenAI, it extracts customer and project details. If a PDF attachment is present, it reads PDF text and uses it for extraction.
• Create offer draft in Google Sheets: It writes a new offer row to Google Sheets with a generated offer number.
• Generate approved offer text (German): Every minute on Google Sheets changes, when an offer row is marked FREIGEGEBEN, it validates required fields, calculates totals/dates, and uses OpenAI to generate the offer text in German.
• Produce and send PDF: It creates a Google Docs offer document in Google Drive, exports it to PDF, stores the PDF, writes the PDF link back to the sheet, downloads the stored PDF, emails it to the customer via Gmail, and updates the status to VERSENDET.
• Supplier inquiries from Leistungsverzeichnis: If the extracted email indicates a Leistungsverzeichnis, it creates a supplier price inquiry draft in a separate Google Sheets tab, emails it to the wholesaler when marked FREIGEGEBEN, and updates the inquiry status to VERSENDET.

Use cases

• SMBs and SaaS operators needing an AI quote generation workflow from customer emails to PDF offers.
• Automation engineers building document automation with Gmail → Google Sheets → Google Drive → PDF → email.
• Teams processing construction/contract quote requests where Leistungsverzeichnis enables supplier price comparisons.

Technical details

• Integrations: Gmail, Google Sheets, Google Drive, OpenAI.
• Workflow logic: if, code, merge, and Gmail-trigger based processing.