Federation of Smart City Services via APIs

In the context of Smart City, it is quite frequent the usage of Smart City API for providing services at web and mobile applications. Most of the solutions using Smart City APIs are focused on a single city. This means that passing from one city/area to another, the users must change application. This happens for the lack of interoperability among Smart City APIs and/or services. In this paper, the problem of federation of smart city services is addressed by proposing a solution for federating smart city APIs. To this end, a formal model has been proposed to federate API services, with efficiency, security, scalability, and capacity of managing overlapped areas of competence, distributed searches, etc. These features are typically not all satisfied by classic GIS solutions which federate the services at level of databases. The solution has been developed in the context of Snap4City European platform enhancing former Km4City API of Sii-Mobility national project with Snap4City (https://www.snap4city.org).