I reverted this due to impending billing changes, but Claude and most LLM providers to my knowledge do offer a way to directly fire a prompt to the LLM in a "headless" or non-interactive mode. Specifically "claude -p <your_prompt_here>" is the way to do it with Claude Code. It allows for using the agent to do a one-off command with a given structured prompt. Originally Lathe would use this from the Go application to allow you to extend a tutorial directly from the UI without directly interacting with the LLM.

You'd have to exec out, so it's alittle clunkier than an IPC, but I think you could achieve what you want with it.