I want to put a Wasabi coordinator in each Wasabi client and allow users to decide whether they want to act as coordinators or not. Currently, a WabiSabi coordinator only requires: * The gettxout RPC call to verify that inputs being registered are unspent and mature * A mining fee rate provider to determine how much each input/output should pay to the network These requirements can be satisfied even by a pruned Bitcoin node and don't present any obstacles. In an ideal world, each coordinator would announce itself (for example, as an onion service), and then clients could agree on which coordinator to connect to for the next CoinJoin round. However, in the real world, malicious actors could create hundreds or thousands of onion services to maximize their chances of being selected. Is there any way to solve this coordinator selection problem without creating a centralized directory of coordinators? any suggestion to read?

I think so, yes. Because the lack of coordinator decentralization ruins the UX by forcing users to research how the whole thing works, find a coordinator and configure the client to use it. Having decentralized coordinators would allow us to select the coordinator for the next round automatically making the feature immediately available after Wasabi installation for everyone.