i want to apply coupon code automatically for logged in customer when it comes view cart page .when page loaded it is automatically applied.if user is not logged in than they want to add manually for that one.
use two shopping cart - rules,
1) for connected users select only the usergroup of register users, without code and the promo you like apply.
2) promo with code and assigned only for the group "NOT LOGGED IN" with a code and the promo you like apply.
the two will swicth when the user is connected because change of usergroup, i hope you assing a usergroup to your registered customers