There is growing interest in city and community scale energy efficiency goals across the US and around the world . Forward thinking developers are expressing interest in developing methods to track the actual operations of new urban developments and campuses. Local governments and developers are exploring how to ensure that the built infrastructure, including buildings, transportation, energy generation and storage assets, is not only designed for energy efficiency, but operates efficiently as well. There is a need for city and district scale tools to support energy analysis from design through operations. Smart city data analytics is a growing area of interest in the smart city technology space. However, while there is enthusiasm for the concept of smart city energy analytics, there is a lack of common semantic data models, interoperable systems, and methods to collect data and support decision-making for operating multi-building city- and district-scale energy systems. Urban developers are asking broad questions about how such a system might be designed, built, valued, maintained, and optimized. This paper describes ongoing research to explore and define a City or District Energy Operations System (CityEOS).