The Book of Jeu survives in the Bruce Codex, a Coptic manuscript acquired in Upper Egypt by James Bruce in 1769 and now at Oxford's Bodleian Library. Carl Schmidt edited the codex (1892); the standard English is Violet MacDermot's in The Books of Jeu and the Untitled Text in the Bruce Codex (1978). The text charts treasuries of light and the seals that open them.
In the text, the risen Jesus teaches the apostles diagrams, literal drawings of seals and names, that let the soul pass the archons of each treasury. It reads like a technical manual, which is precisely why church authorities found it alarming: salvation as procedure rather than faith.
Jeu completes the logic of Gnostic soteriology: if the cosmos is a prison, the saving knowledge is the floor plan and the door codes. The Book of Jeu is esotericism as information security, the divine spark traveling on credentials.
If salvation requires memorizing the seals, is gnosis knowledge or a boarding pass?