Send quotes, invoices, receipts and reminders from Google Sheets with Koutei and Gmail

## Quote, deposit, balance and receipt PDFs from a Google Sheet Set a job row's stage and the next document is made by Koutei (our PDF API for quotes, invoices and receipts) and emailed with Gmail. ### How it works 1. Every 30 minutes the workflow reads your job sheet. 2. The stage picks the document: Quote requested → a quote, Accepted → a deposit invoice, Deposit paid → the balance invoice (the deposit shows as "Amount paid"), Paid in full → a receipt. 3. The row is marked "Sending…"; Koutei checks it for free, does the arithmetic and makes the PDF; Gmail sends it once. The row gets its next stage, number and totals. 4. Every morning, overdue invoices get a polite reminder (at most weekly) with the same PDF. 5. Problems become a note in the row's status, and an email to you. ### Setup 1. Copy the sample sheet: https://docs.google.com/spreadsheets/d/1hA5W-E5knYiUE-9ns4p3khKR9GJfeOS6kCAo59k1kJ4/copy 2. Each job_id is a number or code, never a client's name (Koutei keeps it). 3. Create a free Koutei account, confirm your email and create a Preview only API key in Settings. The free plan has 50 documents a month; previews are free. 4. Add credentials: Google Sheets and Gmail (OAuth2), and Header Auth for Koutei (name Authorization, value Bearer and your key). 5. Fill in Settings: the sheet's URL, your email and your business details. 6. Click Execute workflow. In preview mode every PDF is a free, watermarked preview and every email goes to you, not the client. 7. Then: a Full access key, mode = final, and activate the workflow (Publish in n8n 2) so the schedules run. ### Customize Change the emails in Write the email and each document in its stage node.