This may be a long shot, but feel free to consider Python as "something like nodejs" until a more useful suggestion comes along...
There it could be as simple as (use case: deal with JSON input from HTTP POST):
stdin_json = json.load(sys.stdin)
my_module.my_method(stdin_json['arg1'], int(stdin_json['arg2']), optional_arg=stdin_json['kwarg3']))
note: I'm just typing this out, so count on typos