Ask HN: Are foreign SaaS providers exempt from US corporate taxes?

I'm looking to deploy a SaaS solution from Canada which will have customers in the US as well. If I'm based solely in Canada and have _no_ permanent establishment in the US (including ensuring that my cloud instances were _not_ deployed on any US zones and avoiding employees/contractors from the US), would I be exempt from any US corporate tax? I've been trying to find a clear answer and as with all things related to taxes, it's been utter confusion. Ran this question by the Canadian BDC/EDC with no avail. Practical experience would be appreciated. If there is no need to execute a "Delaware straddle" and there are beneficial tax implications for not doing so, then all the better. TIA