{"product_id":"n8n-ai-invoice-reply-classifier-claude-haiku-gmail-sheets","title":"n8n AI Invoice Reply Classifier: Claude Haiku + Gmail + Sheets","description":"\u003ch3\u003eTurn invoice email replies into instant, triaged categories—using Claude Haiku + Gmail + Google Sheets\u003c\/h3\u003e\n\u003cp\u003eThis n8n workflow automatically watches your Gmail for replies to invoice reminders, uses \u003cstrong\u003eClaude Haiku\u003c\/strong\u003e to classify each response (Paid, Promise, Dispute, Question, or Unrelated), then logs the result to \u003cstrong\u003eGoogle Sheets\u003c\/strong\u003e and applies the matching \u003cstrong\u003eGmail label\u003c\/strong\u003e so you can act fast.\u003c\/p\u003e\n\n\u003ch3\u003eWhat this workflow does\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMonitors Gmail\u003c\/strong\u003e for new invoice replies using a configurable search (default: emails with \u003cem\u003e“invoice”\u003c\/em\u003e in the subject, excluding messages sent by you).\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCleans the reply text\u003c\/strong\u003e by stripping quoted history and signatures to improve AI classification accuracy.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eClassifies with Claude Haiku\u003c\/strong\u003e into one of: \u003cem\u003ePayment made\u003c\/em\u003e, \u003cem\u003ePromise to pay\u003c\/em\u003e, \u003cem\u003eDispute\u003c\/em\u003e, \u003cem\u003eQuestion\u003c\/em\u003e, or \u003cem\u003eUnrelated\u003c\/em\u003e. For promises, it extracts a promised payment date and provides a one-line reason.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLogs to Google Sheets\u003c\/strong\u003e, including a direct link back to the Gmail thread for quick context.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLabels the Gmail message\u003c\/strong\u003e so you can immediately triage: the corresponding category label, or \u003cem\u003eNeeds review\u003c\/em\u003e if the model fails (with the error recorded).\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eUse cases\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eInvoice reminder inbox management for SaaS operators who need rapid follow-ups on \u003cstrong\u003epaid\u003c\/strong\u003e vs \u003cstrong\u003epromised\u003c\/strong\u003e vs \u003cstrong\u003edisputed\u003c\/strong\u003e replies.\u003c\/li\u003e\n  \u003cli\u003eAccounts receivable automation: instantly sort inbound replies and capture structured outcomes in \u003cstrong\u003eGoogle Sheets\u003c\/strong\u003e.\u003c\/li\u003e\n  \u003cli\u003eCustomer support triage: route \u003cem\u003eQuestion\u003c\/em\u003e and \u003cem\u003eUnrelated\u003c\/em\u003e responses without manually reading every thread.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical details\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eIntegrations:\u003c\/strong\u003e Gmail, Google Sheets (via Google OAuth; self-hosted n8n requires a Google Cloud app).\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAI:\u003c\/strong\u003e Claude Haiku 5.5 node for reply classification.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003en8n nodes used:\u003c\/strong\u003e set, code, gmail, merge, switch, sticky note.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGmail labels required:\u003c\/strong\u003e Payment made, Promise to pay, Dispute, Question, Unrelated, Needs review.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSetup:\u003c\/strong\u003e provide the blank Google Sheet URL; the workflow writes the header row on the first run and you can adjust the Gmail search query to match your invoice reminder titles.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"N8N Commerce","offers":[{"title":"Default Title","offer_id":46217922248883,"sku":"N8N-20818","price":54.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0749\/6279\/6723\/files\/N3_JM5QGX7F7Er0US0edS_FMWM8d0e.png?v=1791883337","url":"https:\/\/buyflowscripts.com\/products\/n8n-ai-invoice-reply-classifier-claude-haiku-gmail-sheets","provider":"N8N Commerce","version":"1.0","type":"link"}