Hi Federico, thanks for opening this topic. I was fascinated by this website, in particular their pricing and their claims in their FAQs!
I personally don’t think that using smaller versions of GPT-3 (or free versions, for that matter) diminish the “wow-factor” of these text generation models. Here is how I would do it:

Use a development environment that gives you free GPU power (e.g. https://studiolab.sagemaker.aws/)
Leverage the Huggingface Pipeline API for Text Generation: Pipelines

Done! 


Well not quite - once you have the pipeline running you obviously want to play around with different models, different values for parameters, some prompt engineering, etc. As a starting point you you could leverage the code from the PhilosopherAI itself: philosopherai_demo/philosopher_demo.js at master · mayfer/philosopherai_demo · GitHub
That’s pretty much all there is to it 
Below a screenshot to give you an idea what an output from the model GPT-Neo 1.3B (a popular open-source alternative to GPT-3) looks like:

Capture823×219 7.61 KB

Hope that helps, reach out if any question!
Cheers
Heiko