Ayvu Rapyta is a book written in the Mbya Guarani language and compiled by Paraguayan anthropologist León Cadogan.
Cadogan records the myths and religious tradition of the Mbyá Guaraní of the Guairá Department of Paraguay as told him by, among others, Cacique Pablo Vera.
The book's full title is Ayvu Rapyta: Textos míticos de los Mbya-Guarani and was first published in 1959.
The father, Ñamandu, by virtue of his creative wisdom, or kuaarara, conceived the origins of the human tongue even before the existence of the world.
Cadogan also compiled from his Mbyá associates various songs, prayers and rites essential to indigenous religious life as well as their ethical customs.