Some updates on the progress: 1. Ported the defc macro to Minimallist, removed last bits of Clojure Spec. You can try in a REPL: https://github.com/green-coder/vrac/blob/diy-furry/src/vrac/core.cljc#L36-L43 2. Minimallist will need a refactoring to properly parse and validate destructuring bindings. https://github.com/green-coder/minimallist/issues/8