Integration to external address book?

Is there a way to integrate client and contact information to an existing address book? I have an an address book that is accessible via CardDAV. I would like to use it to store client information for Invoice Ninja invoicing to avoid additional error prone input with the duplication of information.


One option may be to sync the CardDAV with your mobile device and then use the contacts feature to create clients from contacts on your phone. The downside to this approach is it would only work on the mobile app, not the web or desktop apps.