Hi, 

I am trying to use prompt caching future using claude "databricks-claude-sonnet-4" databricks endpoint (wrapped in a ChatDatabricks instance). Using langchain, I set 

 SystemMessage(
                    content=[
                        {
                            "text": cached_doc_prompt,
                            "type": "text",
                            "cache_control": {"type": "ephemeral"},
                        }
                    ]
                ),

for the part of the message I want to cache.

I get this error:

Response text: {"error_code":"BAD_REQUEST","message":"BAD_REQUEST: Databricks does not support prompt cache for the first-party Anthropic model."}

How can prompt caching be achieved in databricks? 

thanks for your help!