A user viewing an online content item using an online content client application can, from within that application, launch an operating application to operate on the content item. The operating application can interact with the online content management provider to obtain a current copy of the content item and to save a modified content item back to the online content management service, e.g., if the user instructs the operating application to save the item. Interactions between the client application, the operating application and the online content management service can occur without requiring the user to manually initiate upload or download of any content items. Operations on an online content item can also be initiated from within an operating application.