This claims provider for SharePoint 2013 leverages Azure AD Graph Client Library to query Azure Active Directory from the people picker. It also gets the groups of Azure users to augment their SAML token, so that permission can be granted on Azure groups.

• Easy to configure with administration pages added in Central administration > Security.
• Connect to multiple Azure AD tenants in parallel (multi-threaded queries).
• Populate properties upon permission creation, e.g. email to allow email invitations to be sent.
• Supports rehydration for provider hosted apps.
• Implements SharePoint logging infrastructure and logs messages in Area/Product "AzureCP".
• Augment Azure AD users with their group membership.

• Customize list of claim types, and their mapping with Azure AD users or groups.
• Enable/disable augmentation.
• Enable/disable Azure AD lookup (to keep people picker returning results even if connectivity to Azure tenant is lost).
• Customize display of permissions.
• Set a keyword to bypass Azure AD lookup. E.g. input "extuser:partner@contoso.com" directly creates permission "partner@contoso.com" on claim type set for this.
• Developers can easily customize it by inheriting AzureCP class and override many methods.