I also need to count messages in an autonomous node, and I use a conversation variable. Then I ask autonomous node to add 1 on every answer it gives the use. You have to give Variable access to the node. Now the problem I have, is the transition in autonomous node. The condition is the messageCount variable is 3, but when the variable {{conversation.messageCount}} arribes to 3, the transition does nothing. It's something random, because the first time I've tried it, it worked. Also, sometimes autonomous node doesn't update the variable...