Dear colleagues, We are pleased to announce a call for papers for a special issue of *Netcom* devoted to *the conditions of possibility of political participatory platforms*. The issue explores what enables these platforms to emerge, operate and endure, or, conversely, what leads to their transformation or disappearance. The call is organized around three main axes: – *professionals, intermediaries, and the work of platform participation*; – *platforms as infrastructures*: servers, maintenance, security, credibility, and digital sovereignty; – *business models, funding, and political economy*. We welcome both empirical and theoretical contributions, in *English or French*. Abstracts of approximately *1,000 words* should be submitted by *15 December 2026*. Full papers are due by *15 April 2027*, with publication of the special issue planned for *January 2028*. *English call:* https://journals.openedition.org/netcom/10893 *French call:* https://journals.openedition.org/netcom/10861 Please feel free to circulate the call widely within your networks. Best wishes, Fabrizio Li Vigni, Khaliq Parkar, Stéphanie Wojcik and Mathieu Brugidou