Creating a ticket as advised from Ethan Jones. Details:

I would be great if we could check if a FF exists in Harness. That way we could fallback to our legacy mode when the FF is not found.

So would it be possible for Harness to add a public method for determining if a flag exists? The targeting or default value doesn't matter. It would be a public method on client. Something like:

def exists?(flag)

@repository.get_flag(flag) != nil

end

(found this from the evaluator.rb your inner_client.rb. uses and looks like it may do the trick if exposed as a public API) (edited)