6pm reads a VietQR entirely on the phone: a small TLV reader, a CRC-16/CCITT-FALSE check, a NAPAS template lookup. Then it opens the payer's bank app. For 28 apps that is a transfer link with account, amount and note filled in; for the rest, the app's home screen, the amount on the clipboard and the QR saved to Photos. This post walks through the code in packages/domain/src/vietqr/ and apps/mobile/src/features/scan/bank-handoff.ts . Everything quoted is from the repo, which is Apache 2.0. ...