Problem

Invoice data is often copied from PDFs by hand, and it is easy to miss something.

What I built

I built a workflow that receives a PDF invoice, pulls out the text, turns it into clean data with AI, checks the required fields, saves valid invoices to Google Sheets and sends a Telegram alert if something is missing.

Workflow

Webhook
→ Extract Invoice Text
→ AI Invoice Extraction
→ Validate Invoice
→ Invoice Validation Route
   → Valid → Save Valid Invoice → Success Response
   → Invalid → Telegram Alert → Error Response

Tech

• n8n
• Groq API
• PDF processing
• JavaScript
• Google Sheets
• Telegram API
• Webhooks

Tested

• Valid PDF is parsed and saved
• Missing fields return validation errors
• Invalid invoice sends a Telegram alert
• API returns success or error JSON

Screenshots