Verify Proof of Delivery Photos with GPT-4o Mini in n8n

Automatically verify delivery proof photos in n8n using GPT-4o mini

This n8n workflow captures proof-of-delivery (POD) submissions from drivers, matches them to your Google Sheets deliveries register, verifies the uploaded photo with OpenAI (GPT-4o mini) vision, and then logs results while notifying both ops and the customer via Gmail and Telegram.

What this workflow does

• Receives a driver submission from an n8n Form containing waybill/order number, recipient name, optional notes, and an optional delivery photo.
• Normalizes and validates the data: generates a POD ID and flags whether a usable photo file is attached.
• Handles missing waybill: if the waybill is missing, the workflow emails ops via Gmail, posts an alert to Telegram, and stops processing.
• Checks waybill in Google Sheets: looks up the submitted waybill in the Deliveries register; if not found, it appends an “Unrecognized waybill” entry to PodLog and alerts ops.
• Handles missing photo: if the waybill exists but no photo is provided, it logs a “no photo” exception to PodLog and notifies ops via Gmail + Telegram.
• Verifies photo with GPT-4o mini: when a photo is provided, it sends the image and context to OpenAI (GPT-4o-mini) to classify the POD as “ok” or “mismatch”, returning a short summary.
• Updates outcomes:
  • If ok: updates the delivery row to Delivered, logs the verified result to PodLog, emails the customer via Gmail, and posts a confirmation to Telegram.
  • If mismatch: logs the exception to PodLog and alerts ops via Gmail + Telegram.

Use cases

• Confirm POD photos for last-mile deliveries and automatically mark shipments as Delivered in your registry.
• Detect and escalate issues like missing waybills, missing photos, unrecognized waybills, or photo mismatches.
• Reduce manual ops effort by using GPT-4o mini vision verification and structured logging in Google Sheets.

Technical details

• n8n nodes: if, set, code, gmail, telegram, sticky note
• Data sources: n8n Form input, Google Sheets (“Deliveries” and “PodLog” sheets)
• AI verification: OpenAI GPT-4o mini vision to classify POD as ok vs mismatch and provide a brief summary