Safe Paths—an MIT-led, free, open source technology that enables jurisdictions and individuals to maximize privacy, while also maximizing the effectiveness of contact tracing in the case of a positive diagnosis for Covid-19. The Safe Paths platform, currently in beta, comprises both a smartphone application, PrivateKit, and a web application, Safe Places. The project is a multi-faculty, cross-MIT effort, with input and expertise from institutes including Harvard University, Stanford University, and SUNY Buffalo; clinical input from Mayo Clinic and Massachusetts General Hospital; and mentors from the World Health Organization, the US Department of Health and Human Services, and the Graduate Institute of International and Development Studies.