diff --git a/hosts/ocaml/bin/sx_server.ml b/hosts/ocaml/bin/sx_server.ml
index 93540f20..9466cff5 100644
--- a/hosts/ocaml/bin/sx_server.ml
+++ b/hosts/ocaml/bin/sx_server.ml
@@ -4000,7 +4000,17 @@ let http_mode port =
                 let body_str = match Sx_ref.eval_expr aser_call (Env env) with
                   | String s | SxExpr s -> s | v -> Sx_types.inspect v in
                 let status = !_pending_response_status in
-                http_response ~status ~content_type:"text/sx; charset=utf-8" body_str)
+                (* HX-Request → render to HTML for htmx; otherwise SX wire format *)
+                let is_hx = has_substring (String.lowercase_ascii data) "hx-request" in
+                if is_hx then
+                  let html = try
+                    let exprs = Sx_parser.parse_all body_str in
+                    let expr = match exprs with [e] -> e | [] -> Nil | _ -> List (Symbol "<>" :: exprs) in
+                    Sx_render.sx_render_to_html env expr env
+                  with _ -> body_str in
+                  http_response ~status ~content_type:"text/html; charset=utf-8" html
+                else
+                  http_response ~status ~content_type:"text/sx; charset=utf-8" body_str)
             with e ->
               Printf.eprintf "[handler] Error for %s: %s\n%!" path (Printexc.to_string e);
               http_response ~status:500 ~content_type:"text/sx; charset=utf-8"