This paper provides a framework for analyzing infinite horizon mechanismdesign problems with limited or without commitment. We derive a canonicalmodel of bargaining games with communication by establishing a revelation principle  in a multi-stagegame where the principal can control the level of transparency (what theseller observes). We also provide, under certain assumptions, a foundationfor take-it-or-leave-it offers in dynamic bargaining and for posted pricesin the durable good monopoly literature.