I managed to make it work with Llama4 models (but not yet with openAI oss-gpt-120b and 20b), but I had to switch from langchain-groq (in Python) to the Groq SDK. I adapted the example in the page https://console.groq.com/docs/structured-outputs and it works. With langchain-groq I’ve tried a lot of things but I always kept getting 400 errors.