________who, at the request of Vyasa, wrote down the text to Vyasa's dictation

According to Hindu mythology, Lord Ganesha agreed to write down the Mahabharata as Vyasa dictated it, on the condition that Vyasa would recite it continuously without pause. This is why Ganesha is also known as Vighneshvara, the remover of obstacles. Janamejaya was the king who heard the recitation, while Vaisampayana and Ugrasrava Sauti were later narrators.