The two features I mentioned, automatic contact discovery and robust offline messaging, are examples of features that I have concluded to be impossible to build without some degree of centralization (there are probably more, but those two were the only ones I could recall off the top of my head). Though it is certainly possible that I simply haven&#x27;t put enough thought into it.<p>Toc&#x27;s original goal was to be a decentralized messaging app that makes <i>no</i> compromises in terms of UX compared to a centralized messaging app. Toc managed to tackle decentralized cross platform sync, but to this day I still have no idea how to approach automatic contact discovery and robust offline messaging.