Supplier Onboarding Validation n8n: Gemini + Gmail + Webhook

Validate supplier onboarding automatically—PDF parsing, Gemini extraction, and Gmail correction emails

The Supplier Onboarding Validation n8n: Gemini + Gmail + Webhook workflow streamlines supplier onboarding by receiving submissions via webhook, extracting data from PDF documents, using Google Gemini to convert unstructured text into structured fields, and then either sending suppliers a correction/rejection email or saving validated suppliers to Google Sheets and Google Drive.

What this workflow does

• Receives onboarding submissions through a POST webhook containing supplier details (e.g., supplier_name, supplier_email) and an array of document URLs.
• Downloads and processes each document in a loop: the workflow fetches the PDF from its URL, extracts the text, and prepares it for analysis.
• Extracts structured data with Google Gemini to produce normalized JSON fields such as company, tax, contact, insurance, and certification data.
• Validates required documents and required fields across submissions, including:
  • Required document type presence
  • Required field completeness per document
  • Cross-document company name consistency
  • Expiration date checks
  • Basic email/tax ID formatting
• If validation fails, it compiles a detailed issue list, refines the correction message with Google Gemini, and sends a rejection/correction email to the supplier via Gmail.
• If validation passes, it creates a supplier master record, appends it to Google Sheets, creates a supplier folder in Google Drive, uploads the original documents, and emails confirmations to both the internal team and the supplier via Gmail.

Use cases

• Automating supplier onboarding intake for a procurement or vendor management process.
• Reducing manual review by validating documents and extracting structured supplier data from PDFs.
• Automatically requesting missing/expired documentation with clear, Gemini-refined correction instructions.

Technical details

• Webhook (POST): expects supplier_name, supplier_email, and body fields including docum (document URL array).
• n8n nodes/tools: if, set, code, wait, gmail, webhook (plus integration with Google Gemini, Google Sheets, and Google Drive as described).