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Card payments & delegated spend

A card backed by an onchain balance turns every purchase into a public record. Merces lets a cardholder spend from a private balance, so the merchant gets paid without the cardholder's spending history becoming readable.

This depends on delegated spend: the ability for another party to move funds on a user's behalf, which a card flow requires and which Merces supports natively.

The flow​

  1. The cardholder pays at the merchant's terminal.
  2. The payment network checks and locks funds.
  3. The purchase is finalised at the point of sale.
  4. Funds move from the cardholder's private balance to the card provider's private wallet — or, alternatively, directly to the merchant's private account.
  5. The card provider periodically sweeps its account and off-ramps.
  6. The card provider settles with the merchant in fiat.

What stays private​

The cardholder's balance and their transaction history stay encrypted throughout. Settlement between the card provider and the merchant happens off the public ledger, in the provider's normal fiat rails.

Where to start​

Private virtual account covers the account and its transfers.