Which is correct "chatting with you" or "chatting to you"?
Both are correct, but there is a very slight difference in meaning.
Chatting WITH implies a give-and-take. You are engaging in that activity along with another person.
Chatting TO, on the other hand, comes across as you, alone. You can chat, or talk, TO anything - it doesn't have to talk back.
When you talk TO people, they listen. When you talk WITH someone, they talk back. Same with chatting.
I hope this helps.