Every time I have negotiated hard regarding a situation like this, I have regretted it.<p>The reason is that in this moment, you feel the work you&#x27;ve done must be worth a lot, because it is fresh in your mind, and because cognitive dissonance dictates you believe you haven&#x27;t wasted all those hours of coding.<p>Meanwhile you are still imagining the big payoff from the company succeeding ... which is a great motivator when you&#x27;re working on the startup, but when you are parting ways, you should remember being super successful is incredibly rare. You would benefit from bringing rationality in and remembering it was all always a long shot.<p>So you will tend to overvalue the company, based on the work you&#x27;ve done, while undervaluing the personal relationships and lessons learned.<p>Take a long view. Do whatever deal will make your cofounder happy. Be nice in every way to every one involved, make good on any promises, and give it time.<p>When you look back on this a year from now you will be glad you did.