Ask HN: How much equity to accept as the sole tech co-founder in this case?

This is for a tech company that has a CEO and a CPO without a prototype, customers or any other full-time hires. They are about to close on their seed funding though and I'll be joining after right after that. The equity will be from the founders pool and the salary is somewhat negotiable between 100k-200k per year before taxes. In terms of the other founders, one of them has a gotten their startup acquired before for 10s of millions (I think - undisclosed figure but I put that number together from the parent company's total funding) and the other founder has no prior startup experience. One of them has some limited tech experience.

What would you accept in this case as the CTO?