It is possible that Amos recorded his prophecies by himself or he may have dictated them for someone else to write down. The first-person accounts seem to suggest that he had a strong hand in putting his revelations into writing (e.g. Amos 5:1; Amos 7:1–9; Amos 8:1; Amos 9:1).1
1 The words of Amos, who was among the shepherds of Tekoa, which he saw concerning Israel in the days of Uzziah king of Judah and in the days of Jeroboam the son of Joash, king of Israel, two years before the earthquake.