You keep referring these payments both made and received by your client as being for "smart contracts".  What is clear from the materials available on the internet, these are for referrals (which resemble Ponzi schemes, IMHO, and from the perspective of other observers on the Internet as well as the SEC of the Philippines) and not for processing "smart contracts".  If it's for the latter, that would amount to mining, which is covered by the guidance issued by the IRS.