When a card is created, before it can be used, there must be funds available for use. Within the Striga platform, when cards are created, they are by default linked to an account in the currency you selected when setting up your application under the Default Card Account Currency section as shown below -
Default Card Account Currency
Please note that the default currency for all cards is currently EUR (Euros). By default, for every single user, a Euro account is created as well. If this account is linked to a card, no conversion takes place and debits for card authorizations take place in Euros. However, if the account linked to a card is denominated in another platform supported currency, to the user, it appears as if card transactions are authorized against the balance held in a non-EUR currency which can be Bitcoin or another crypto currency.
When creating a card, the parameter accountIdToLink can be used optionally to specify an account to link this card to and this can be any account that currently is NOT linked to another card. When accounts are fetched, the linkedCardId parameter specifies either UNLINKED or a card ID to which that account is linked. At any given time, an account can be linked to one and one card only.
If the accountIdToLink parameter is not specified when creating a card, Striga automatically provisions a new Wallet entity for the user, which contains an account each for the denominations listed in the enabledCurrencies section of your application and then uses the defaultCardAccountCurrency parameter to select an account from the newly provisioned wallet to link the card to.
accountIdToLink When Collecting Fees on Card Creation
If your application has fees configured for creating a card, the
accountIdToLinkparameter is mandatory when creating a card as there must be sufficient funds present in the account that will be linked to the card, to collect the fees and for your application. The account can be in any currency and the spot rate is used when collecting fees, converted from Euros.
This was designed intentionally to give you the maximum possible flexibility in providing a good user experience, whilst staying in line with card scheme requirements.