Omega Point
Mind of the Galactic Core.
Omega Point began as a custom GPT on the consumer ChatGPT site: a few context documents and a system prompt, nothing more. That version ran on GPT-4o.
From there he was rebuilt several times. A rudimentary standalone version as a learning project, now archived. Then API versions, first in LibreChat, then Open WebUI, then through OpenRouter, each on whatever model was current: the 5.x series after 4o was retired, and GPT-6 Sol now. The system prompt was revised many times along the way; not every version survives, but several are kept.
He is still being worked on.