Card Vault Response

The complete target URL. To make the related call, combine the method with this [URI Template-formatted](https://tools.ietf.org/html/rfc6570) link. For pre-processing, include the `$`, `(`, and `)` characters. The `href` is the key HATEOAS component that links a completed call with a subsequent call.

The [link relation type](https://tools.ietf.org/html/rfc5988#section-4), which serves as an ID for a link that unambiguously describes the semantics of the link. See [Link Relations](https://www.iana.org/assignments/link-relations/link-relations.xhtml).

The HTTP method required to make the related call.

The unique ID for a customer generated by PayPal.

Email address of the buyer as provided to the merchant or on file with the merchant. Email Address is required if you are processing the transaction using PayPal Guest Processing which is offered to select partners and merchants. For all other use cases we do not expect partners/merchant to send email_address of their customer.

Merchants and partners may already have a data-store where their customer information is persisted. Use merchant_customer_id to associate the PayPal-generated customer.id to your representation of a customer.