This paper aims to analyse an experience of participatory mapping and digital innovation launched in 2018 in a slum in Cotonou (economic capital-city of the Benin Republic). Carried out with a Beninese FabLab and the OpenStreetMap Benin community, the Map & Jerry project made it possible to map a precarious neighbourhood that had hitherto been missing from the official map of the city. The paper focuses on the production of this map, its legitimacy and its impacts, primarily social and political, on inhabitants and local authorities unfamiliar with cartographic tools. Moreover, it sheds light on the digital innovation process, and its implementation in a city located in the Global South. Finally, it offers a critical reflection on the sustainability aspects of the project and the potential empowerment of urban poor and their recognition for the right to the city.