Expose extensionattributes in Azure AD with the Office 365 Graph API
A lot of customers use extensionattributes in their on-premises active directory. These can be synced with AzureAD Connect. But you can only find them with PowerShell in their mailbox. When a user does not have an mailbox these attributes are not exposed on any other way.
Please make these extension attributes available over the Office 365 Rest API so we can use them in our applications without using other field which are not created for that purpose.
This was shipped in November. This is now available on the user resource object called onPremisesExtensionAttributes (https://developer.microsoft.com/en-us/graph/docs/api-reference/v1.0/resources/user) .
I agree. ExtensionAttributes are very useful and we also need to be able to select/filter users based on their values.
Found out that the attributes can be exposed in the beta endpoint when you add the attributes to the Directory extension in the synchronization client. I wrote a blog post about it: https://arjansp.nl/2aDaaEu