Common API - Office.Auth

Provides an access token to the add-ins web application
Calls the Azure Active Directory V 2.0 endpoint to get an access token to your add-in's web application.
Enables add-ins to identify users. Server-side code can use this token to access Microsoft Graph for the add-in's web application by using the "on behalf of" OAuth flow.
This API requires a single sign-on configuration that bridges the add-in to an Azure application.
Office users sign in with Organizational Accounts and Microsoft Accounts.
Microsoft Azure returns tokens intended for both user account types to access resources in the Microsoft Graph.

let myvar: Office.Auth = Office.context.auth 
let myvar: Office.Auth = OfficeRuntime.auth