  Much research has studied foundations for correct and reliable
communication-centric systems. A salient approach to correctness uses session
types to enforce structured communications; a recent approach to reliability
uses reversible actions as a way of reacting to unanticipated events or
failures. This note develops a simple observation: the machinery required to
define asynchronous semantics and monitoring can also support reversible
protocols. We propose a process framework of session communication in which
monitors support reversibility. A key novelty in our approach are session types
with present and past, which allow us to streamline the semantics of reversible
actions.
