One tap from cashier
to wallet.
The whole exchange takes less than a second and replaces every part of the paper-receipt ritual — including the awkward 'do you want it printed?'
A coin that cannot lie.
The puck is the smallest part of the system, but it does the cryptography that lets you trust everything that follows.
NFC chip · NTAG 424 DNA
A tamper-resistant secure element with a rotating signature. Each tap produces a unique URL — receipts cannot be cloned, replayed, or scraped.
Loop antenna
A flat coil tuned to 13.56 MHz. Reads through glass, leather phone cases and most countertops. Range is 1–4 cm, by design.
Tamper seal
A thin breakaway lacquer between the puck and the surface. Lift the puck, the seal breaks, the dashboard flags it within the hour.
No battery, no cable
The puck draws power from the phone's field. It is good for at least a million taps and survives a wet bar towel.
No app, no account.
The whole experience runs in the browser the phone already trusts. Nothing to download. Nothing to type. Nothing to consent to twice.
The least we possibly can.
Privacy is a load-bearing wall here, not a marketing checkbox. We store enough to satisfy the tax authority and nothing else.