There i s a very important ziyaarat of Imam-e-Zamaana (a.t.f.s.) called Ziyaarat-e-Aale Yaaseen. Renowned traditionalist Shaikh Abbas Qummi (ra) has mentioned it as the very first ziyaarat of Imam Mahdi (a.t.f.s.) in his celebrated work, 'Mafaateeh al-Jenaan'. It is highly recommended to recite this ziyaarat on Mondays and Fridays. These beliefs have been stated in this ziyaarat as well and Imam-e-Zamaana (a.t.f.s.) himself is made as a witness over these beliefs. "Then you be a witness on what I have made you as a witness."
https://onneshghi.blogspot.com/2018/12/imam-mahdi-atfs-spring-of-life_30.html