Endpoint to access Customer Information?

When our customers sign up, they fill out a form with information our moderators need to fulfill their orders, but that information only seems accessible via the admin>nexus>customers>[customer]>Customer Information tab.

The custom fields that output with the /nexus/purchases/ GET do not include these fields, but there does not seem to be a way to GET something like /nexus/customer/ according to your documentation. How can I GET this information from the system?

Thanks!