This does not work on older clojure versions

Hi, I ran into weird errors for couple of hours when I tried to create a new client as per docs in README.md

When I checked your reps, I found clojure 1.11. 

My legacy code is on clojure 1.10

When I updated to clojure 1.12 the issues disappeared 

I think a warning message at load time about minimum clojure version would be helpful