Paid Credentials

Analogous to the Free Credentials workflow, any user (as well as the operator) can offer and accept paid credentials. The content of the credentials is the same as described in the Credential Contract. The acceptance of the credential by the holder will set up a billing process, where a regular payment in Canton Coin is made from the Credential Holder to the Issuer. The payment details are defined in the offer for the Paid Credential. The execution of the billing process is triggered by the automation run by the operator.

Offer-Accept a Paid Credential

The Paid Credential issuance follows an offer and accept process. Any user can issue paid credentials to another user of the application.

The billing information is defined in the Paid Credential Offer as the following:

• Fee per Day: Daily subscription fee (denominated in USD)

• Billing Period: The frequency at which the billing process is executed by the automation (in minutes)

• Credential Fees reserve amount USD: the initial amount of Canton Coin (denominated in USD) that will be locked as a deposit upon acceptance of the offer

• Credential Fees Target reserve amount USD: The Target reserve amount defines the maximum value of the locked deposit. In case there are Canton Coin transfers from the Issuer back to the Holder (e.g. rebates, reward sharing, etc.) the Target reserve amount determines how much will be put into the deposit. The remaining amount will be transferred directly to the holder.

The acceptance of the offer requires the holder to lock the required amount of Canton Coin as a deposit. Technically, this is achieved by passing a Canton Coin contract Id as an argument to the Accept choice.

The acceptance of the offer will create the credential contract as well as a Credential Billing Contract, which is used by the operator to execute the transfers from Holder to Issuer.

Cancel/Reject Offer

The Paid credential offer can be canceled by the issuer or rejected by the holder.

Billing Process

The credential utility uses Canton Coin for the billing of paid credentials. The following transfers are executed during the lifetime of a CredentialBilling contract:

1. At creation of the contract, the holder locks up a certain amount of Canton Coin as deposit (holder → holder CC transfer).

2. At each billing cycle, the deposit is unlocked and part of it is transferred to the issuer to pay for the credential (holder → issuer).

3. The remaining deposit amount is re-locked (holder → holder) and will be used at the next billing cycle. At any time, the holder can top up its deposit (holder → holder).

4. At any time, the issuer can distribute a rebate to the holder (issuer → holder).

5. At any time, the issuer can distribute a rebate to the holder and use part of it to top up the holder’s deposit.

6. At archival of the contract, the deposit is unlocked (not a transfer per se).