Replying to my own comment - it's trivially possible to replace `api_base` in settings.yaml. The only problem is that Ollama doesn't support OpenAI style embedding endpoint yet. But looking through PRs to Ollama, this is very close to being merged. All steps before actual embedding work fine with e.g. Llama3-8B.

You can use litellm with drop_params for embedding endpoint

I'd just try setting the env vars and see what happens, if it breaks you'll have to read the code though.

https://microsoft.github.io/graphrag/posts/config/overview/

You will have to do a fair amount of refactoring.