The famous armor 'Genta ga Ubuginu' (Genta's clothes as a newborn) was sometimes used as a proof of being the direct descendant of the Minamoto clan, and there is a view that suggests that Kawachi Genji that passed it down was the direct descendant of the Minamoto clan.
時々、有名な甲冑「源太が産衣」が源氏嫡流の証として、それを伝える河内源氏が源氏嫡流とする立場がある。