If a workflow sends a text and the person replies, who answers?

If the AI agent is enabled for that channel, the AI answers. The workflow sends the first message and the AI picks up the conversation from there, so treat the workflow message as an opening message or icebreaker.

Put the instructions for handling replies in the agent's prompt. For example, for a Google review request: send an SMS asking how the experience was, and in the prompt say that if they rate it seven or below, ask why and try to make it right, and if higher, ask for a review.