I’m building a small-footprint payment flow for in-store purchases that lets employees tap an RFID card (nfc or rfid laundry token sewn to a laundry bag), have the customers identity recognized on the spot and have the sale billed automatically. Every tap should: • read the RFID token (smartphone NFC scanning must also work for staff), • match or create the customer record, • complete the payment, • push the full transaction into Airtable and, in the same moment, mirror it to a connected Google Sheet for back-office reporting. Ability to enter new clients Ability to see real time of payment is declined (insufficient funds) I’m looking for a turnkey prototype: working code, any middleware you choose, and concise setup notes for beta testing. Please include an estimate of hours and timeline along with the approach you would take (hardware, reader libraries, Airtable ↔ Google Sheets sync method, etc.). Possible 5 year royalty deal based on sales for future support of software In addition to upfront development cost.