Rabbi Yaakov Koppel Hager (; died 29 August 1787) was a Hasidic rabbi and disciple of the Baal Shem Tov. He was the father of the founder of the Kosov dynasty.
Hager was born in Kolomyia (modern-day Ukraine) to Nehemiah Feivel Koppel, a merchant. Feivel was the son of Rabbi Yaakov Koppel Kamiel, an expellee of Schnaittach, Germany, and Pearl (who might have actually been his grandmother), a relative of Yom-Tov Lipmann Heller. After marrying, he adopted the surname Hager for unknown reasons.
He married Chaya (died 16 May 1772). She was the daughter of his paternal uncle Zalman, son-in-law of David HaLevi Segal.
During his career, Hager didn't lead a congregation, nor did her serve on a rabbinate board, but made his living from a small resale store. He was not known as a titled tzaddik among his circle, but it is believed that the Besht saw him as a hidden tzaddik. He approached the path of Hasidism, and met the Baal Shem Tov, who he became a disciple of, and later became a public messenger of his. According to Hasidic oral tradition, the Besht promised Hassid that the Jewish community of MaramureÃÂ would be under the rabbinate of his descendants.
He was called a "Shvitinik" by the gentile population of his town due to the way that he held his hands over his eyes occasionally, even when trading, and would read the verse "<u>Shivviti</u> ADONAI lenegdi tamid ki mimini bal-emmot". (Psalms 16:8)
In his final years, he lived in Tysmenytsia, where he helped grow the Hasidic movement in the area and defended Rabbi Meshullam Egra following a dispute that arose between him and the residents of the city.
Hassid had 3 children: