Kyalibę̃ is a constructed language ("conlang") inspired by the languages of Amazonia. The language's fictional speakers, the Sulilibe, live along the banks of the Madeira River in Brazil. Their world is shaped by the distinction between dry and wet: the highlands versus the floodplain, the dry season versus the wet season. This book is a full grammar of Kyalibę̃, including a dictionary and a full description of the language's many features, including areal features like noun incorporation, serial verb constructions, grammatical evidentiality, nasal harmony, and nominal tense. This book also contains rich worldbuilding information about the Sulilibe: their history, their way of life, their kinship structure, the ways they avoid conflict, and how their life has changed since the arrival of Christian missionaries in the 1970's. At times, their culture impacts the spoken language: linguistic taboos drive the need for a productive process of taboo deformation while properly-initiated male speakers use the three sacred consonants to give religious speech an otherworldly sound.