How to decide how to share equity between 2 people for a new startup?

My friend and I are planning to do an incorporation soon for a idea we have. It's not my idea to begin with (currently I'm just doing a prototype for that person for some money), but that person is a business person and won't be doing any coding overall. I am the only one that will be doing all the dev work and dev research (I may get some help later by paying money and not equity), plus some of the business things like presentations, forms, marketing. The idea involves making a web app, android app and iOS app eventually, and uses more complex things like AI and machine learning. I also consider myself valuable because I have connections/friends to lawyers and a VC if I need any mentoring.

Based on all these, some people I talked to pretty much say I should get more than 50% equity, since the devs will be putting in more work upfront at least in the beginning to make the product. But what are some good suggestions for how to split it. When the other person first suggested we work together and incorporate, they said 50/50, but now I think to be fair based on effort going to be put in it, it shouldn't be that.

Does anyone have experience with this sort of stuff?

Thanks