Chat Completions

def chat(
    self,
    messages: List[ChatCompletionMessageParam],
    chat_template: Optional[str] = None,
    chat_template_content_format: ChatTemplateContentFormatOption = "auto",
    add_generation_prompt: bool = True,
    continue_final_message: bool = False,
    tools: Optional[List[ChatCompletionToolParam]] = None,
    documents: Optional[List[ChatCompletionDocumentParam]] = None,
    mm_processor_kwargs: Optional[Dict[str, Any]] = None,
    **kwargs: Any,
) -> List[ChatCompletionOutput]:
    """
    Generate chat completions from conversation messages.

    Parameters:
    - messages: List of conversation messages with roles and content
    - chat_template: Custom chat template for message formatting
    - chat_template_content_format: Content format handling ("auto", "string", "openai")
    - add_generation_prompt: Whether to add generation prompt
    - continue_final_message: Continue from the last assistant message
    - tools: Available tools for function calling
    - documents: Context documents for retrieval
    - mm_processor_kwargs: Multimodal processing arguments

    Returns:
    List of ChatCompletionOutput objects with generated responses
    """

from vllm import LLM

llm = LLM(model="microsoft/DialoGPT-medium")

messages = [
    {"role": "system", "content": "You are a helpful assistant."},
    {"role": "user", "content": "What is the capital of France?"},
]

response = llm.chat(messages)
print(response[0].message.content)

class ChatCompletionMessageParam:
    role: str  # "system", "user", "assistant"
    content: str  # Message content

class ChatCompletionOutput:
    message: ChatMessage  # Generated response
    finish_reason: Optional[str]  # Completion reason