A method for providing a message-based communications infrastructure for automated call center operation is described. A call from a telephony interface is accepted. The accepted call includes an incoming stream of verbal speech. The incoming stream of verbal speech is converted into incoming text from a caller into a call center. The call is automatically assigned at a session manager to a session and to a live agent. The incoming text is progressively processed through an agent application during the session through a customer support scenario interactively monitored and controlled by the live agent. The live agent sends outgoing text messages that are converted into an outgoing stream of synthesized speech to the caller.