Automated Invoice Collection & Data Extraction Using Vision API and LLM

This workflow automates the process of collecting uploaded invoices, extracting text using Google Vision API, and processing the extracted text with an LLM to produce structured data containing key transaction details such as date, voucher number, transaction detail, vendor, and transaction value.
The final data is saved to Google Sheets and a notification is sent to Telegram in real time.

✨ Key Features

• Invoice Upload Form
  Users can upload invoice images through a provided form.
• Google Drive Integration
  Files are stored in a specified Google Drive folder with a shareable preview link.
• OCR via Google Vision API
  Converts invoice images to text using TEXT_DETECTION.
• Data Structuring via LLM
  Uses LLM model to parse and structure data.
• Structured Output Parser
  Ensures consistent output with required columns.
• Data Cleaning
  Cleans and formats numeric values without currency symbols.
• Google Sheets Sync
  Appends or updates transaction data in Google Sheets (matched by file ID).
  Template: Google Sheets
• Telegram Notification
  Sends a transaction summary directly to a Telegram chat/group.

🔐 Required Credentials

• Google Vision API Key → for OCR processing.
• OpenRouter API Key → to access the Gemini Flash LLM.
• Google Drive OAuth2 → to upload and download invoice files.
• Google Sheets OAuth2 → to write or update spreadsheet data.
• Telegram Bot Token → to send notifications to Telegram.
• Telegram Chat ID → target chat/group for notifications.

🎁 Benefits

• Fully automated from invoice upload to structured reporting.
• Time-saving by eliminating manual transaction data entry.
• Real-time integration with Google Sheets for reporting and auditing.
• Instant notifications via Telegram for quick transaction monitoring.
• Duplicate prevention using file ID as a matching key.
• Flexible for accounting, finance, or administrative teams.