I have an user adding form when an user is added the form should be cleaned. Since this add-customer function called every time subscription is triggered. I was expecting customer-form will refresh.

So, everything is rerendered, but the customer-form don't?

I'm also see at least one strange thing here. The (add-customers ...) usually should be [add-customers ...]

The same goes for the (customer-form ...)

https://github.com/reagent-project/reagent/blob/master/doc/UsingSquareBracketsInsteadOfParens.md