The term Kathakas in the sense of “storytellers” appears in ancient Hindu texts, such as the Mahabharata.
वेदवेदाङ्गविद्वांसस्तथैवाध्यात्मचिन्तकाः |
चौक्षाश्च भगवद्भक्ताः सूताः पौराणिकाश्च ये ||२||
कथकाश्चापरे राजञ्श्रमणाश्च वनौकसः |
दिव्याख्यानानि ये चापि पठन्ति मधुरं द्विजाः ||३||
Followed by the scholars of the Vedas and Vedangas, and by those who ponder on their soul,
by persons skilled in music, by the devotees of Bhagavata, (…)
by Kathakas (reciters of the sacred lore), by dwellers of forests, (…)
by those who sweetly recite celestial histories.
— Adi Parva CCVI.2-3, Mahabharata, Book