Frequently asked questions

Last Updated: December 23, 2021

What is a prepaid card?

A prepaid card is a Gnosis Safe smart-contract wallet.

Why do I need a prepaid card to spend crypto?

A Card Pay prepaid card has a managed gas policy that enables tokens inside the safe to be used as native gas tokens.

How do I request a payment?

To request a payment, you will need a payment profile. You can create a payment profile through the web dApp at https://app.cardstack.com/card-pay/payments or in the wallet (see this guide).

Why do I need a payment profile to request a payment?

Cardstack supports payments via prepaid cards to enable simple payments between users. In order to stay compliant with regulatory definitions of prepaid cards, the payment can only be single directional.

Does a prepaid card have a private key?

The prepaid card is implemented as a Gnosis Safe, which does not have a private key because it is a contract. This Gnosis Safe has 2 owners, your EOA and a contract called the PrepaidCardManager.

What can the above owner do with the private key?

In order to perform a safe transaction, 2 signatures must be sent to the Gnosis Safe contract. One signature is from your wallet (for which the private key lives in Cardstack Wallet), and the other signature comes from the PrepaidCardManager contract via an EIP-1271 contract signing. Any action that you take on your prepaid card requires you to sign the transaction from Cardstack Wallet. The PrepaidCardManager will contribute its signature if it sees that the transaction looks legitimate. 



Can I charge / top off / refill a prepaid card?

We haven't built a mechanism to officially recharge the prepaid card; however, since the prepaid card is just a contract, we certainly cannot stop an entity from sending DAI.CPXD tokens to it to add additional value. In the near future, we will be adding an official recharge capability.

Some additional information: The PrepaidCardManager will not permit non-.CPXD tokens to be sent from your prepaid card. Due to this, we would not recommend sending tokens to a prepaid card address by hand, as you may end up trapping your tokens in the prepaid card. We’d recommend waiting until the official recharge function is enabled. 


Can I transfer a prepaid card to another user?

Yes, if you created the prepaid card by issuing it through the "Issue prepaid card" flow in the dApp. To transfer the prepaid card using the mobile app, press and hold the prepaid card for 2 seconds while on the wallet screen and it will open a transfer function.

Note: If the card says "non-transferable", you will not be able to move it since you did not issue the prepaid card. 


Can I create another prepaid card and move spend between
 my cards?

Currently we do not allow movement of value between prepaid cards. The PrepaidCardManager will not permit this type of transaction. This is a feature we will likely implement in the near future. In the meantime, you are able to create a payment profile and request a payment, which you can pay yourself. Once you have at least 5 DAI.CPXD in the payment profile, you can issue yourself a new prepaid card. Why do I see 0.00 CARD inside of my depot balance despite having claimed rewards?

If these conditions are true when referring to your depot address, - there exists a card balance as confirmed by the block explorer - there exists a card balance when inspecting subgraph data (our graphql api) it is very likely, that the UI is intentionally showing your balance at 0.00 CARD. We have this concept of dust in our cardstack protocol. This means that the balance is too miniscule (after converstion to USD) for the user to pay sufficiently any gas to do anything on the blockchain. Having a dust balance in a wallet is very problematic so we made an affordance to hide this from the user.