I’m looking for a developer who can build a lightweight payment gateway that runs inside an iframe and can be embedded on a separate domain. The gateway will process one-time payments through Credit/Debit Cards only, and I don’t need to collect any extra user data beyond what’s essential for the charge. Scope of work • Create a secure checkout page that lives on my server and loads inside an iframe. • Integrate a mainstream card processor (Stripe, airwallex, or a similar PCI-compliant API) for one-time transactions. • Implement tokenization so card details never touch the parent site. • Provide clear embed code (HTML/JS) so the iframe can be dropped into any external domain and still complete the payment flow smoothly. • Handle success, failure, and cancellation callbacks and expose them to the parent page via postMessage (or a comparable method) so I can trigger custom UI responses. • Add minimal styling hooks so I can match the host site’s look and feel. • Supply a brief setup guide and a sandbox/demo environment for testing before we switch to live keys. Deliverables 1. Hosted checkout page with secure iframe integration. 2. Back-end code (language of your choice) connecting to the card processor. 3. Front-end embed snippet and callback documentation. 4. Basic test cases confirming transaction success and error handling. The goal is a clean, self-contained module I can reuse across multiple sites without exposing sensitive data. If you have prior experience building similar embedded gateways, I’d love to see a quick example or reference.