Kodi-k-kavai is one among the fourteen Siddhanta Shastras in Saiva Siddhanta literature composed by Umapati Shiva. It is a kind of poem on the temple flag in four stanzas in Tamil. According to the tradition (popular story), Umapati Sivam was one among the three thousand priests of Tillai (Chidambaram). Due to some misunderstanding with the rest of his colleagues, Umapati left Chidambaram and settled at Tiruvetkalam temple (Korravan Kudi).
As per a popular story, a grand festival used to be celebrated at the temple of Nataraja at Chidambaram. To mark the commencement of the festival, it was customary to hoist the flag bearing the emblem of Nandi (bull), which is the Vehicle or vahana of Shiva, in the temple on the first day. However, when the priests tried to hoist the flag, it did not move upwards despite their sincere efforts. When they were disconcerted by this mishap, an oracle was heard that if Umapati Sivam was invited to the place, the flag would move up. The priests realized their folly in alienating Umapati Sivam and persuaded him to go over to Chidambaram. It was then that Umapati composed the poem called kodi-k-kavi.
In this work, the author elucidates the purpose of hoisting the flag, the importance of the emblem of the bull on it, the import of the five sacred letters (na ma si va ya) and the prostrations to Siva, the purpose of the organization of the temple festivals, the discipline by which the souls are purified, the grace of Bhagavan Shiva who is beyond human comprehension, and finally the spiritual union with him.