My wife and I aren't together but are still legally married. We share custody of our kids. Neither one of us want child support.

If neither of you are under any type of public assistance or receiving governmental benefits, you should be able to agree depending on your placement arrangement and what your incomes are, to have a hold open on child support. Understand in family court matters, any agreements must be reduced to writing and must be approved by the court to be binding; similarly, the agreements are subject to court scrutiny on whether they should be approved or not.