Juxt were very vocal about making Crux available beyond Clojure (can't find the exact quote right now, unfortunately). Perhaps the last time you checked it, any non-Clojure support was still WIP. However, since then they definitely have Java API available (Javadoc here: https://crux-doc.s3.eu-west-2.amazonaws.com/crux-javadoc/20....), as well as REST API (see https://opencrux.com/docs#restapi).