Can we get a marital agreement without a divorce?

After 8 years of marriage my husband and I want to get a trial separation. We are both Jewish and our families are strongly discouraging a divorce. We want to try counseling with our Rabbi and avoid a divorce, but that might not be possible. Can we have a separation agreement that states what each of us will pay and be responsible for in our home and continue to live together in separate bedrooms? Would such an agreement be valid? We live in Sacramento and we both travel a lot for work so often we aren’t sleeping in the same house anyway but there are times when we do.