It seems to be due to a lack of validation for the type of that second parameter, where Crux is expecting a map. When you pass in a string it doesn't throw, because get seems to be happy accepting a string (get "asdf" :a) => nil and the nil is comparable See the definition of tx-v: https://github.com/juxt/crux/blob/6df9f72fcba23d2fa966d67a5105c63496c0d492/crux-core/src/crux/node.clj#L36-L40 I think this should be semantically the same as crux/latest-completed-tx though and I wouldn't expect there to be any performance difference there. By contrast crux/latest-submitted-tx calls through to the tx-log, which is typically a more expensive operation In any case, I've made a note on the project board that we could potentially benefit from the extra validation, thanks for reporting it 🙂

ah yes, typed completed here and submitted into the repl.. tired brain. thanks for looking into it

np, tired brains need to support each other! 😄