Authenticating client applications with different permissions in REST API

I'm tasked with creating a REST API for storing and retrieving data about various documents. The API will be used by various client, such as mobile and desktop applications or a windows service importing the documents from another system. The applications should only have access to the resources of the user that's currently logged in, while the service should be able to access all of the documents. In such situation, is it possible to have a unified authentication so that all the clients can use the API in the same way?