Cipay allows you to pay fiat invoices with your ETH on Optimism.
Cipay lets you pay brazilian PIX* invoices with ETH on optimism. Just open the app, scan the invoice qrcode and sign a message.
Example flow. Alice sold her UBI tokens for ETH and wants to pay Pix invoice with it.
*PIX is a system free to use system to allow payments and transfers between banks.
A minimally custodial/payment system like this would be impossible without a fast and cheap way to send ETH. Luckily L2s are coming fast. To make this app I used:
Meta transactions to run business logic before broadcasting the transaction to the network.
Optimism for fast and cheap ETH (or any token) transfers.
Starkbank as the bank to finalize the payment.