Have you ever tried to setup a Figwheel project with Datomic ? I call lein new figwheel mwe-cider-cljs-datomic, add Datomic as a dependency (just like the doc says) and I stumble upon an exception. Any additional configuration? Here is a minimal working example: https://github.com/piotr-yuxuan/mwe-figwheel-cljs-datomic