Thanks for re-surfacing @elvismercury. As mentioned in #396527, this is a Bitcoin Dev Project project and the source code is here -- contributors and PRs welcome!

Nothing is being trained here. The responses are generated based on the same sources as bitcoinsearch.xyz. We take the content from the most relevant sources and then ask OpenAI (could use another LLM) to summarize the raw content. This limits the hallucinations as we don't make up any answers that don't have content to support it, but also limits its range. It does well with technical questions that people have written long mailing list posts about, but not very well with general purpose bitcoin things. We also implemented L402 for DoS protection.