Current trends in serendipity research and collaborative ethics point to the importance of cultivating bottom-up approaches to designing for datafication in urban centers. The focus on pattern recognition in big scale data analysis, combined with an exponential growth in and infrastructural support of ubiquitous information and communication technologies (ICIs), has led to concerns about whether smart cities will turn urban environments into sites that leave little space for diverse and unplanned encounters. We take the position that smart cities need to take citizen agency into account and explain how to conceive the smart city in terms of serendipitous opportunity and community engagement. We do this by elaborating on the idea of situated serendipity, and how this kind of serendipity is co-constructed by technologies, citizens, and the urban setting. We subsequently present a methodology in line with recent work with sensory ethnography, to better understand the meaning and value of serendipity in the smart city. Ultimately, we propose a new way to imagine the ‘living lab’ as a cultivator of serendipity, through techniques developed in the fields of design, innovation, improvisation, citizen science and participatory ethics.@en