iPhone
Apple Wallet
A store card signed with the same Pass Type ID as the membership card. The balance sits in the primary field, the NFC payload is handed over encrypted via VAS.
Add the card
Android
Google Wallet
A loyalty object through the Google Wallet API: the points balance holds the visits left, Smart Tap is on, so the turnstile can read it.
What you get
Both cards for a made-up holder, drawn from the same data as the real ones. The pictures change every hour.
How it would work
Load
The cashier sells ten visits. The server creates the pass and hands over a link or QR code, no plastic card.
Tap
At the turnstile the reader asks the phone for the pass over NFC and gets the card ID.
Count down
The server books one visit and pushes the new balance to the wallet. At zero the card greys out until it is topped up. Try it: the till takes the ID a reader types, or the card number from your pass.
Try it with your own reader
Elatec TWN4 firmware
The keyboard firmware for an Elatec TWN4 MultiTech reads this card too: hold it to the reader and it types the ID, followed by Enter, straight into the till. It is handed out on request only, because the image carries its key in plain form.
For an ACS WalletMate II there is a key package instead: it stores the demo key in the reader’s Apple slot, and the reader decrypts the pass itself. Both come through the same request.