Digital sovereignty is not achieved simply by replacing one platform with another. A public institution may host its own server and still inherit someone else’s assumptions about identity, processes, moderation, participation, and governance. This talk presents [Bonfire](https://bonfirenetworks.org) , an AGPL-licensed modular framework for building self-hosted and federated digital spaces using open protocols such as ActivityPub. Rather than asking every administration, university, or public body to join the same network and using the same platform and set of features, Bonfire allows each organisation to assemble a space around its own needs: public communication, institutional communities, cross-organisation collaboration, research networks, or moderated discussions. Institutions can operate the infrastructure themselves or work with cooperative hosting providers, define their own roles and participation boundaries, and connect with peer organisations without surrendering their data, policies, or roadmap to a single vendor. Drawing on Bonfire’s work with research and education partners - including the University of Warwick, Princeton University and UCL - the talk will examine what this model changes in practice. It will also address what remains difficult: operational capacity, engagement and participation, moderation, migration, interoperability, and the long-term sustainability of public-interest infrastructure. Attendees will leave with a practical framework for evaluating sovereign communication tools: not only where a service is hosted, but who controls its data, code, policies, evolution, and relationships with other institutions and with a realistic understanding of where Bonfire can contribute today.