Contact person: Business Client

Phone:Show

Email:Show

Location: Chennai, India

Budget: Recommended by industry experts

Time to start: As soon as possible

Project description:
"i’ve finished building a small e-commerce site in plain HTML, CSS and vanilla JavaScript, with Supabase handling authentication, products and orders. The last missing piece is payments. I already hold live and sandbox credentials from PhonePe and want that to be the only gateway—we will not be adding PayPal, Stripe or anything else.

Scope
• Create a seamless PhonePe integration for one-time purchases in a single currency.
• Support direct UPI intent / collect flows so buyers can pay via their preferred UPI app.
• Keep the front-end lightweight: no framework libraries, just clean JavaScript that plugs into my existing checkout page and calls the Supabase backend.
• On the server side, verify checksum / signature, store the transaction status beside the order row in Supabase and trigger my existing “order-fulfilled” function.
• Provide clear comments and a short markdown file outlining any environment variables, headers and callback URLs so I can re-deploy immediately.

Acceptance
A test card payment in sandbox and a live ₹1 transaction must both update the order record to “paid” and fire the fulfilment webhook without javascript console errors or unhandled promise rejections.

If you have implemented PhonePe or similar UPI flows before and can wrap this up quickly, let’s get started." (client-provided description)