The assistants API is fantastic; I was just getting started with it. This news makes me reconsider -- but I also think it's inevitable that a compatible API will be released with open source underlying LLMs. I've deployed the OpenAI-compatible completions API over Llama2 in production with vLLM, and it works perfectly.
Do you know if there are any projects working on this? Even something like a high quality json-tuned base model would go a huge way toward replicating OpenAI's current product.