Should I go with InvokeAsync as much as possible?

[dziedrius]

Hi, still very new to this and I think some of the abstraction is puzzling me.
Maybe I overlooked, but I could not find explanation when to use which abstraction and to me it seems that sometimes there's an abstraction leak.

For example, I can execute chat completion in several ways:

kernel.InvokePromptAsync(... // directly
kernel.InvokeAsync(... // through kernel function KernelFunctionFactory.CreateFromPrompt
kernel.GetRequiredService<IChatCompletionService>().GetChatMessageContentsAsync(...

So initially, I was trying to use kernel.InvokeAsync, as it seemed like a most generic way and at least in some tutorials that was the way, as it supports plugin conventions.
Then I spent quite a while searching how to pass chat history into it - may be some convention how to name some kernel argument or something that is stored and expected in external context, etc. Finally going through source code I found, that it won't accept chat history, as deep inside it does this:

if (result.AIService is IChatCompletionService chatCompletion)
{
     asyncReference = chatCompletion.GetStreamingChatMessageContentsAsync(result.RenderedPrompt, result.ExecutionSettings, kernel, cancellationToken);
}

Hence it seems that if I need to attach chat history, I need to go with kernel.GetRequiredService<IChatCompletionService>().GetChatMessageContentsAsync(..., but I was wondering if there is some kind of guidance when to use what.

[matthewbolanos]

Yes, as of today, you'll need to use the underlying service to do anything with the chat history object. This is currently flagged as a gap that we'd like to solve this summer. Our goal is to provide helpers within prompt templates that allow you to write prompts with chat history objects. Once that's available, you'll be able to use InvokePromptAsync. We should have an initial proposal out in a few weeks.