This Purana is basically a preaching to the sage Vashishth by Agni. In his turn, Vashishth narrated it to Vyasaji, who related it to Sutji. Ultimately, Sutji narrated Agni Purana to an assembly of the sages in Naimisharanya.
Agni Purana, one of the major eighteen Puranas, contains descriptions and details of various incarnations of Vishnu. It also has details account about Rama, Krishna, Prithvi, and the stars. It has a number of verses dealing with ritual worship, cosmology, history, warfare, and even sections on Sanskrit grammar, meter, law, medicine, and martial arts. Tradition has it that it was originally recited by Agni to the sage Vasishta.