I need to know if I have any chance at joint custody

I have two children boys that are 16 and 14 they live with their dad in randolph,ny and I just moved to falconer because of a job and my car was not on the road. I made a verbal agreement with the boys dad that I would move to falconer and save some money so I could move closer to them and get a house and take care of them financially. he and I made an agreement that i would pay 80 dollars a week and pay the cell phones and the agent and any extra stuff needed which I have and have paid 100 dollars a couple of times when i made extra money. well now I receive a paper in the mail stating that he is going after full custody for the boys