mlx-community work with OpenToys. The README lists gpt-oss 20B. Paste the Hugging Face repo name into the Models page to switch.
It is a large model. Check you have the memory to spare before switching, since a heavy LLM slows every reply.
LLM
gpt-oss
Use OpenAI’s open-weight gpt-oss from mlx-community as the local LLM for your ESP32 AI toy.
gpt-oss models from