Array of Things (AoT) is a network of interactive, modular sensor boxes that collect real-time data on a city’s environment, infrastructure, and activity for research, policy, and public use.  Each box, or “node”, supports a set of embedded cyberinfrastructure and sensing services, each with power, Internet, and with the capacity to evolve annually to incorporate new technologies and experiments. All data will be open, and a peer review process will enable community-contributed enhancements and guide regular technology upgrades over many years. The instrument will also provide for industry partners to experiment with innovative technologies and services, while also supporting industry-academic collaboration in research, development, education, training, and public outreach.