Other platforms

Anything that can post a signed form and receive a signed JSON webhook works (Shopify custom apps, Laravel, Django, Node, Magento…). Checklist:

• Create the order as pending and use its ID as invoice_id.
• Redirect the customer with the signed form. Never expose the API secret to the browser.
• On webhook: verify signature → check amount → skip duplicates → mark paid → return 200.
• Use return_url only to show a thank-you page; do not trust it as proof of payment.
• Optionally run a small job that calls the Status API for orders still pending after a while.