Doesn't sound like it but unfortunately that's not enough information for me to tell. It might be. BTW a "contract" includes pretty much every transaction, even if immediately performed.
From ATO tax treaties: https://treasury.gov.au/tax-treaties/income-tax-treaties/ to USA DTA (double taxation avoidance) "Convention between the Government of Australia and the Government of the United States of America for the Avoidance of Double Taxation and the Prevention of Fiscal Evasion with respect to Taxes on Income"
http://www.austlii.edu.au/au/other/dfat/treaties/1983/16.htm...
> Article 12 Royalties
> (4) The term "royalties" in this Article means:
> (a) payments or credits of any kind to the extent to which they are consideration for the use of or the right to use any:
> (i) copyright, patent, design or model, plan, secret formula or process, trademark or other like property or right;
So, by 12.(a)(4)(i), if a customer pays you so they can redistribute your copyrighted code (i.e. a component), it's a "royalty".
BTW Reading it literally, this "right" includes the mere use of copyrighted material - but here it's meant as more serious aspects of copyright, like the right of (re)distribution.
IIRC, there's a wrinkle: in something like a compiler, which is used by the customer and not redistributed, but includes some part that is redistributed (like stdlib), this anxilliary distribution doesn't alter the character of the primary transaction. IIRC, the ATO stated this in what I think is called a "tax note" - a decision made internally (i.e. not held by a court).
tl;dr you can get away with a little redistribution