PaisaFlow

A small, sharp library for the problem nobody in Pakistan has solved neatly: taking a payment through a local mobile wallet and knowing, reliably, whether it went through. It provides a unified checkout surface, a webhook receiver that verifies and de-duplicates callbacks, and a sandbox mode that simulates the whole asynchronous lifecycle - pending, authorised, settled, failed - without touching a bank. The data layer is Drizzle over Postgres, and the QR that starts a payment is generated on the server so it can be handed to a terminal that has no internet.