Kaiyyata was a grammarian from Kashmir who is believed to have lived around 1200 CE. His father was Jaiyyata, surnamed Upadhyaya, and his teacher was Maheshwara. Kaiyata composed a commentary by the name of Pradipa, on the grammar work Mahabhashya by Patanjali. Mahabhashya itself is a commentary on Ashtadhyayi on Panini with a critique of Katyayana.
At the beginning of Pradipa commentary, Kaiyyata offers prayers to Vishnu, Shiva and Goddess Saraswati. He comments on each phrase/word of the original text and the commentary brings out the hidden links and significances. The grammar work of Kaiyyata marks the end of the phase of Ashtadhyayi study in the sutra order of the text. It gave away to the study of Ashtadhyayi, based on derivation of words.
Grammar of Kaiyyata has set the standard for later study of Mahabhashya. It is said that many of the passages of Mahabhashya, which were hitherto unintelligible, were interpreted by Kaiyyata satisfactorily. Hence Mahabhashya was commented mostly with Pradipa commentary of Kaiyyata. There were many commentaries on Pradipa of Kaiyyata, the prominent among them being Pradipodyota of Nagesha (also known as Nagoji Bhatta) and Udyotana of Annambhatta.