The 6-Step Pipeline

Gmail (Email arrives) 
    ↓
Claude AI (Extract structured data)
    ↓
Parser (Convert JSON to usable fields)
    ↓
Validator (Check if extraction worked)
    ↓
Google Sheets (Save data)
    ↓
Mark as Read (Prevent reprocessing)

Tools & Their Roles

1. n8n (Orchestration Engine)

What it does: Connects all the tools, manages data flow, handles triggers and scheduling.

Why it's here: n8n is a workflow automation platform. It lets you build "if this, then that" logic without coding. In this case:

• Watches for new unread emails every minute
• Passes email data to Claude
• Takes Claude's response and sends it to Google Sheets
• Auto-marks emails as read

Cost: Free tier handles thousands of executions/month

2. Gmail Trigger (n8n node)

What it does: Polls your Gmail inbox every minute for unread emails matching specific keywords.

Configuration:

• Searches for emails with subjects containing: invoice, order, inquiry, request, quote, delivery, payment
• Excludes drafts, spam, trash
• Captures full email body (not just preview)
• Optional: Downloads attachments

Why filtered: Prevents processing irrelevant emails (newsletters, internal messages, etc.) and saves Claude API calls