Do you actually know how many shares the founders have received? And how does that compare to what you are being offered? There is no standard definition of "

Do you actually know how many shares the founders have received? And how does that compare to what you are being offered? There is no standard definition of "founder" or "co-founder." They could offer you half of what they are getting and refer to you as a "founder." I assume that wouldn't solve your concerns. I'd put the title aside and think about what you are actually looking for from this experience. It goes without saying that you should be getting a very significant piece of equity if they expect you to work for free. You are taking a huge risk. But I get the impression there is something else about the "founder" designation that is meaningful to you. What is it?