Ashtadhyayi has been written by Panini.

Ashtadhyayi, a monumental work in Sanskrit linguistics, was composed by the ancient Indian grammarian Panini. Completed around the 4th century BCE, it is a systematic and exhaustive treatise on the structure and rules of Sanskrit grammar. Comprising eight chapters or “adhyayas,” it meticulously analyzes the phonetic, morphological, and syntactic aspects of the language.

Ashtadhyayi’s brilliance lies in its concise and logical presentation, outlining the principles governing the formation of words and sentences. It introduces the concept of “sutras,” aphoristic rules that encapsulate linguistic principles concisely. The work significantly influenced linguistic studies and grammatical traditions, not only in Sanskrit but also in subsequent languages.
Panini’s Ashtadhyayi remains a foundational text, vital for understanding classical Sanskrit and serving as a reference for linguistic analysis. Its enduring relevance and impact extend to various linguistic disciplines, making it a cornerstone in the study of language structure and formulation of grammatical rules.