This document discusses single sign-on mechanisms for widgets. It outlines requirements including not requiring learners to create accounts for each widget and allowing developers to easily build widgets that require or don't require login. The document describes an existing architecture from Gonzalez et al. that uses a learning management system (LMS) with standalone tools. It also lists 14 requirements from Gonzalez et al. related to interoperability, access transparency, privacy, and more. Potential fulfillment of the requirements and scenarios and suggestions for single sign-on using an identity provider and OAuth are presented.