I don't know why, but here's a way to get all existing version of https://osu.ai (Do not support any of the guys behind.)
As of 02/21/2026
To download any version simply update the download url with the version.
Exemple: https://osu.ai/api/download-desktop-client?url=https://cdn-releases.osu.ai/OsuAI_1.7.8_x64_en-US.msi
Unreleased update: 1.8.0
Version 0.1.0: It exists!
Version 0.6.0: It exists!
Version 0.7.0: It exists!
Version 0.8.0: It exists!
Version 0.9.1: It exists!
Version 1.0.0: It exists!
Version 1.1.1: It exists!
Version 1.1.2: It exists!
Version 1.1.3: It exists!
Version 1.1.4: It exists!
Version 1.2.0: It exists!
Version 1.2.1: It exists!
Version 1.3.2: It exists!
Version 1.4.1: It exists!
Version 1.5.2: It exists!
Version 1.6.2: It exists!
Version 1.6.3: It exists!
Version 1.6.6: It exists!
Version 1.7.0: It exists!
Version 1.7.8: It exists!
Version 1.8.0: It exists!