I never got anywhere with what I had been trying to do, but my first task was "learn Rust - for real this time". :/ Sadly, that got bumped down several pegs on my list. That being said - the server-side just returns HTML, so most of the work will be in structuring your requests. If you're all-in on htmx, your endpoints can just return snippets of HTML; if you want boosting/graceful fallback, you can implement a handler that looks at the HTTP headers to determine whether to return the whole page, or just a portion of it.