I tried :union and :and with no luck.

(mu/union
   [:map
    [:state keyword?]
    [:failure {:optional true} any?]
    [:value any?]]
   [:map-of keyword? string?])

Well, actually it’s working. Had to replace :union with mu/union 🙂

good to hear it works! I think union puts :or around the two here.

:thinking_face:

but, there is an issue to solve this elegantly.