Process receipt images with GPT-4o-mini, WhatsApp & Google Sheets automation

🧾An intelligent automation system that turns WhatsApp into your personal receipt manager — integrating Meta WhatsApp Cloud API, Google Drive, Google Sheets, and OpenAI GPT-4o-mini via n8n. 🎥 Demo: Watch the Loom walkthrough --- ⚙️ What It Does The AI-Powered WhatsApp Receipt Bot automates the complete invoice handling process through a conversational interface. Workflow Summary: 1. User sends a receipt image via WhatsApp. 2. The bot automatically downloads the media using the WhatsApp Cloud API. 3. The image is uploaded to a Google Drive “Invoices” folder. 4. The file is shared publicly, generating a shareable URL. 5. The receipt is analyzed using OpenAI GPT-4o-mini to extract structured data: Store name Items purchased Payment method Total amount 6. The extracted details are appended to a Google Sheet for record-keeping. 7. The bot sends a human-readable summary back to WhatsApp with emojis and the invoice link. Output Example: 🏬 Store: Big Bazaar 📝 Items: Rice, Detergent, Snacks 💳 Payment: Card 💰 Total: ₹1520.75 🔗 Link: https://drive.google.com/file/d/1abcXYZ/view This system eliminates manual expense tracking, improves accuracy through OCR, and provides a seamless way to manage receipts in real time. --- 💡 Use Cases | Scenario | Description | | ------------------------------------- | --------------------------------------------------------------------------------------------------------------------- | | Personal Expense Management | Automatically store and categorize receipts from daily purchases. | | Business Accounting | Collect employee expense receipts through WhatsApp and centralize them in Google Sheets. | | Freelancer or Consultant Tracking | Keep a digital record of client reimbursements or software purchase receipts. | | Family Budgeting | Family members send receipts to one shared WhatsApp number, all data gets logged centrally. | | E-commerce / Delivery Teams | Drivers or delivery agents send invoices from the field to WhatsApp; data automatically goes to the accounting sheet. | --- 🔧 Setup 1. Accounts and Tools Needed | Tool | Purpose | Link | | -------------------------- | ------------------------------------------- | -------------------------------------------------------------------------------------------- | | Meta Developer Account | To access WhatsApp Business Cloud API | https://developers.facebook.com/apps | | Google Cloud Account | For enabling Drive and Sheets APIs | https://console.cloud.google.com | | n8n Instance | Workflow automation engine (local or cloud) | https://app.n8n.cloud | | OpenAI API Key | For GPT-4o-mini model OCR + reasoning | https://platform.openai.com/account/api-keys | --- 2. Meta Developer Setup (WhatsApp Cloud API) 1. Go to Meta Developer Dashboard → My Apps → Create App → Business type. 2. Add WhatsApp product under your app. 3. Retrieve the following from WhatsApp > Configuration: Permanent Access Token Phone Number ID WhatsApp Business Account ID 4. Add these credentials in n8n → Credentials → WhatsApp API. Use the same credentials for WhatsApp Trigger and Send Message nodes. 5. Verify webhook in Meta with your n8n webhook URL. Important: In your HTTP Node, set the header as: Authorization: Bearer <accesstoken> Replace <accesstoken> with your WhatsApp Cloud API permanent token. Without this, the workflow will fail to send or receive WhatsApp messages properly. --- 3. Google Drive Setup 1. Create a folder named Invoices on your Google Drive. 2. Copy the Folder ID (found in the Drive URL). 3. In Google Cloud Console → APIs & Services → Enable APIs: Enable Google Drive API Enable Google Sheets API 4. Go to Credentials → Create Credentials → OAuth 2.0 Client ID. 5. Download the credentials.json file. 6. Upload this to n8n → Credentials → Google Drive OAuth2 API. 7. Authorize the connection on first workflow run. --- 4. Google Sheets Setup 1. Create a new Google Sheet titled Invoices. 2. Add the following headers in Row 1: store name | discription | imageur