In the perspective of Agenda 2030, and more particularly in order to mobilize public-private partnerships more frequently, the city is presented as an original object of study. The latter, in view of the data that may be collected on a targeted scale, can serve as a basis for negotiating new types of transport, sustainable development and public health contracts. Behind the concept of the intelligent sustainable city, now promoted worldwide by the UN, there is a significant legal challenge. Without representing a model that can be fully transposed, the Singapore Smart Nation Initiative has the merit of illustrating this problem. It can undoubtedly serve as a basis for reflection for cities and States wishing to use data collection as a lever in the search for sustainable development.