The report analyses the processes of building initiatives and public policies for the Agro-Ecological Transition (AET) of food systems in ten countries of the South. The results come from the first stage of the TAFS project (Agroecological transitions for sustainable food systems: arguments for public policies). The hypotheses were, on the one hand, the weight of political regimes and international cooperation in the translation and emergence of AET and, on the other hand, the fact that the dominant conventional production model is the biggest obstacle to the development of AET. The study consisted of applying the same framework to analyse the processes of building TAE on a national scale, using cross-references and methods from the sociology of public action and political sociology. The results show a diversity of conceptions of AET, of actors, of construction processes and, at the same time, of results in terms of instruments and their implementation.