The OpenID ProviderClient AX modules provides the functionality of transferring user information between OpenID providers and relying parties (clients) as defined in the official OpenID specification on Attribute Exchange.
This is the OpenID provider counterpart. Please check the corresponding OpenID Client AX module for relying parties based on Drupal. But this can also be used perfectly to transfer information from or to applications which are not based on Drupal, but implement the OpenID AX specification.
This module can be used in combination with the OpenID Profile module to define which attributes to transfer.
Development sponsored by erdfisch