# Create the system prompt, or use the override
    system_prompt_ = system_prompt_override or system_prompt(
        data_source_obj,
        data_description_str,
        extra_instructions_str,
    )

    # Default chat function if none provided
    create_chat_callback = create_chat_callback or partial(
        chatlas.ChatOpenAI,
        model="gpt-4.1",
    )

    return QueryChatConfig(
        data_source=data_source_obj,
        system_prompt=system_prompt_, # HERE
        greeting=greeting_str,
        create_chat_callback=create_chat_callback,
    )