This paper aims at establishing an associative relation between the proliferating digital technologies, the physical context of the urban fabric, its inhabitants and the multiplicity of their activities as an emergent phenomenon of contemporary urbanity. It introduces a methodological framework for the development of an interactive urban system, installed within urban open public spaces, in the form of a hybrid interface that can serve as a platform designated for both citizens and municipal planning authorities. This particular system harnesses and analyzes real-time, quantifiable traces of diverse everyday urban activities and subsequently feeds this analyzed information back in a looped manner to citizens via the proposed public interfaces. Subsequently they can observe, interact and declare their own activity-driven, customized spatial and infrastructural usage and transformation alternatives. In other words, the platform does not only imply interaction at an information exchange level, but rather aims to provoke a complex variety of inter-relations between the social and the technological via real-time spatial adaptation and customization possibilities. The proposal focuses towards a system that is perceived as an integral part of the urban environment and less on the development of a specialized application or website platform that only overlays an additional virtual layer to the already existing ones in the contemporary cities. By devising such a socio-technical interaction-driven approach towards urbanism, our proposal intends to deploy a trans-scalar understanding of the emergent relations between people, space and ambient technologies that can, further, enrich the urban pluralities within the twenty-first century city.