Common standards can boost digital transformation in cities by enabling interoperability, sharing of best practices, and creating open innovation ecosystems. The FIWARE Foundation is working with over 100 cities in 22 countries to develop common APIs, data models, and a maturity model for smart cities. This includes a platform for open data publication and standard data models to integrate information from different city sources and make it accessible through common APIs. When cities adopt these common mechanisms, it becomes more attractive for solution providers to create portable governance solutions and innovative business models that unleash the potential of open data.