Living with in laws, who should claim my kids?

We lived in my in laws basement apartment rent free this year while my husband went to school and worked part time. We have two young children who I care for 100% of the time (stay at home mom) and we provide everything besides living expenses for them. We were planning on claiming them and getting about 4500 in the EITC but now my in laws are planning on claiming my children as their dependents because we technically lived in their household but I provided all care, food, insurance, clothes, etc. So who legally has the right to claim them?