My ex wants to see me

I’m in a little pickle and I don’t know what to do. I ended things with my ex last October we still have each other on our socials and every now and then we check in with each other (specifically he messages me). I don’t know what it is but when he does I really don’t want to chat, I keep my responses as short as possible. I just don’t want to engage in conversation. At one stage a couple months ago he messaged saying he missed me and hoped in the future we can try again. He said I didn’t need to respond so I didn’t. Anyway, I just received a message from him asking me if I would be interested in catching up. I honestly don’t want to. I don’t know how to say no without coming across as rude or something. I’ve got no feelings for him but I know that he probably does and I don’t want to give him the impression something might happen.