Common APIs - APIs that were introduced with Office 2013. This is loaded for all Office host applications and connects your add-in application with the Office client application. The object model contains APIs that are specific to Office clients, and APIs that are applicable to multiple Office client host applications. All of this content is under Common API. This object model uses callbacks.
Outlook also uses the Common API syntax. Everything under the alias Office contains objects you can use to write scripts that interact with content in Office documents, worksheets, presentations, mail items, and projects from your Office Add-ins. You must use these Common APIs if your add-in will target Office 2013 and later. This object model uses callbacks.
Supported host applications
Learn more about supported hosts and other requirements.
Open API specifications
As we design and develop new APIs for Office Add-ins, we'll make them available for your feedback on our Open API specifications page. Find out what new features are in the pipeline, and provide your input on our design specifications.