Re: the meaning of stateless

My other takeaway would be to use PUT to initiate the transaction --
the URL being provided with the confirmation of the purchase, and the
method chosen reflecting the creation of a new transaction resource in
a visible fashion -- status changes from 404 to 200/303/40(1|3|10),
which would be an unambiguous indicator of user action matching what
the logs say, if the hypertext represents the transaction directly.

This achieves fidelity of reproduction of the transaction itself, but
only if our shared understanding of the media type may be resolved in a
dispute by using various open-source Web browsers.  As opposed to some
proprietary black-box user-agent provided by one party in the dispute...

-Eric