A new open-source version of the popular GPT language model

Curious:Gretel is claimed to be open source, but what's in Github is clients to use it's online API which has a limited free option. How does one arrive at the "open source version of the popula GPT language model" claim? Curious...

It’s been trained on millions of public datasets and allows developers and data scientists to create new variations of synthetic text and labels for their datasets. Enjoy!