Ideally that would be a local relay like Citrine from nostr:nprofile1qqs827g8dkd07zjvlhh60csytujgd3l9mz7x807xk3fewge7rwlukxgpzpmhxue69uhkummnw3ezumt0d5hsz9thwden5te0wfjkccte9ejxzmt4wvhxjme0qy88wumn8ghj7mn0wvhxcmmv9uzk8xwq. I want to try to stay away of storage for as long as possible and let other apps do that work. But yes, if nothing works, then Amethyst can just have a database and rebroadcast relays into the network.
Another thing to integrate into amethyst 😅