how can you finetune gpt-4 or 3.5? The shell/wrapper around a request to open AI is not any worthy piece of software, It'd be more impressive to vend those services. Otherwise it's basically just a few scripts.
https://cloud.google.com/vertex-ai/docs/generative-ai/models...
You can generate the training data for this with 3.5 and 4 and tune smaller models with the resulting data. For lots of tasks, this results in robust results, which btw are also faster than 3.5 turbo.