1.The knowledge of the Vastu (3) (object of valid organ of cognition) gained through the statements/verbal testimony made by an Āpta (unimpeachable authority).
āptavacanādāvirbhīitamarthasaṃvedanamāgamaḥ
(Pranata 4.1)
2.Verbal testimony of an Āpta (unimpeachable authority)- the canonical works.
āgamo ṇāma attavayaṇaṃ.
(ĀvaCū 1p.28)
3.Kevalajñānī (omniscient), Manaḥparyavajñānī (mind-reader), Avadhijñānī (clairvoyant),
Caturdaśapūrvī (the ascetic having knowledge of all the 14 Pūrvas (canonical works of earlier lore)), up to Abhinnadaśapūrvī (possessed of the knowledge of entire ten Pūrvas (canonical works of earlier lore))- all these are also called Āgama (2) (canonical work).
(Nandī Ti p.174)