Using AWS to pass in an object and associations


I, I have an object and associations, say order and line_items.
I want to submit this order and its lineitems to a central server using

One way is to have an AWS method to submit the order object, and another
method to submit each line_item individually (as I can’t have a typed
array as an :expects parameters) - so I can’t submit all my line_items
in one go. This is expensive, though - I want to keep my AWS calls to a
bare minimum.

Is there a better way? Say building up a YAML or XML string and shoving
all that into an :expects parameter? Or am I missing some other obvious