You do not need to know any of this to use it, in the same way you do not need to know how a card machine talks to your bank. But most people find they trust something more once they know there is no clever bit hiding in the middle.
1. The shop asks for a specific amount
The till works out what you owe and turns it into a request: this amount, to this wallet, for this order. That request goes onto the tag on the counter, or onto the screen as a code.
It is only a request. Nothing has been charged, nothing has been reserved, and the tag holds no money. It is a note saying what is being asked for — closer to a written price than a card terminal.
It also expires, usually after ninety seconds, so a tag sitting on the counter cannot pay for the order before yours.
2. You approve it, on your phone
Your phone reads the request and your wallet opens with the amount already filled in. You see who is being paid and how much, before anything happens.
Then your face or your fingerprint. That unlocks a key held on your device — not a password checked by a company somewhere, but a key that has never left your phone — and that key signs the payment.
This is the part worth understanding: the signing happens on your device, by you. Nobody else can do it, including the shop, including us. There is no version of this where a payment happens without your thumb on the sensor.
3. The money moves, directly
The signed payment goes onto the network, and the money goes from your wallet to the shop's.
Not to a company in the middle that passes it on later. Not into a holding account for three days. From you, to them, in one step. There is no intermediary to fail, delay it, or take a percentage on the way past.
Nothing sits in the middle. That is the entire difference, and everything else follows from it.
4. Both sides see it
The shop's till is watching the network and sees the payment arrive, which is why the screen goes green while you are still standing there. Your app sees the same thing and saves your receipt.
Both of you are reading the same public record, independently. Neither is taking the other's word for it, and there is no third party asserting that it happened.
So what could go wrong?
You tap and nothing opens. Usually the phone did not read the tag. Move it, or ask them to show the code instead. Nothing has been paid.
The amount looks wrong. Do not approve it. The amount is filled in by the shop's till, so if it is wrong the till is wrong. Once approved there is no undo.
You approved and the screen has not changed. Give it a few seconds. If it still has not, do not approve again — check your app first, because your receipt will be there if it worked.
Somebody asks for your recovery phrase to fix any of the above. That is a scam, every single time, with no exceptions. Nothing that goes wrong at a till is ever solved by giving somebody that phrase.
The bit that is doing the work
Everything above rests on one idea: you can prove a payment is yours without giving anybody the ability to make payments as you.
A card number cannot do that. It is a secret that has to be shared to be used, which is why every shop you have ever bought from holds a copy and why fraud is an entire industry. A signature is different — it proves this specific payment came from you and is useless for anything else.
One gesture. Nothing shared. Nothing in the middle. That is the whole design.
The app is free, holds nothing of yours, and you can look around before connecting a wallet.