This chapter argues that both the negotiation process and the contents of each international agreement are shaped by the member states’ desire to signal their anti-corruption commitment to various audiences. Signaling motives thus serve as scope conditions for diffusion—moderating its effects and explaining why some organizations resist the trend. The chapter explains member states remain crucial because their motives serve as a scope condition for the diffusion processes that shape international agreements. At least implicitly, the design of agreements within international organizations has usually been studied from a strict principal-agent perspective. International bureaucracies and non-governmental organizations may both carry significant weight in International organization (IO) decision-making. In light of the primacy of member states in IO decision-making, their motives to develop anti-corruption agreements are the most plausible scope condition. By adopting an anti-corruption agreement within the framework of an IO, member states can address a variety of audiences: domestic constituents; other member states; and external actors.