[Frontend] Clean up type annotations for mistral tokenizer (#8314)

tests/async_engine/test_chat_template.py

 import pytest
 
-from vllm.entrypoints.chat_utils import apply_chat_template, load_chat_template
+from vllm.entrypoints.chat_utils import (apply_hf_chat_template,
+                                         load_chat_template)
 from vllm.entrypoints.openai.protocol import ChatCompletionRequest
 from vllm.transformers_utils.tokenizer import get_tokenizer
 
@@ -87,7 +88,7 @@ def test_get_gen_prompt(model, template, add_generation_prompt,
         add_generation_prompt=add_generation_prompt)
 
     # Call the function and get the result
-    result = apply_chat_template(
+    result = apply_hf_chat_template(
         tokenizer,
         conversation=mock_request.messages,
         chat_template=mock_request.chat_template or template_content,

vllm/entrypoints/chat_utils.py

@@ -23,6 +23,7 @@ from openai.types.chat import (ChatCompletionMessageToolCallParam,
 # yapf: enable
 # pydantic needs the TypedDict from typing_extensions
 from pydantic import ConfigDict
+from transformers import PreTrainedTokenizer, PreTrainedTokenizerFast
 from typing_extensions import Required, TypeAlias, TypedDict
 
 from vllm.config import ModelConfig
@@ -31,7 +32,7 @@ from vllm.multimodal import MultiModalDataDict
 from vllm.multimodal.utils import (async_get_and_parse_audio,
                                    async_get_and_parse_image,
                                    get_and_parse_audio, get_and_parse_image)
-from vllm.transformers_utils.tokenizer import AnyTokenizer
+from vllm.transformers_utils.tokenizer import AnyTokenizer, MistralTokenizer
 
 logger = init_logger(__name__)
 
@@ -379,6 +380,9 @@ def _parse_chat_message_content_parts(
             audio_url = _AudioParser(part)["audio_url"]
 
             mm_parser.parse_audio(audio_url["url"])
+        elif part_type == "refusal":
+            text = _RefusalParser(part)["refusal"]
+            texts.append(text)
         else:
             raise NotImplementedError(f"Unknown part type: {part_type}")
 
@@ -433,6 +437,21 @@ def _parse_chat_message_content(
     return result
 
 
+def _postprocess_messages(messages: List[ConversationMessage]) -> None:
+    # per the Transformers docs & maintainers, tool call arguments in
+    # assistant-role messages with tool_calls need to be dicts not JSON str -
+    # this is how tool-use chat templates will expect them moving forwards
+    # so, for messages that have tool_calls, parse the string (which we get
+    # from openAI format) to dict
+    for message in messages:
+        if (message["role"] == "assistant" and "tool_calls" in message
+                and isinstance(message["tool_calls"], list)):
+
+            for item in message["tool_calls"]:
+                item["function"]["arguments"] = json.loads(
+                    item["function"]["arguments"])
+
+
 def parse_chat_messages(
     messages: List[ChatCompletionMessageParam],
     model_config: ModelConfig,
@@ -446,6 +465,8 @@ def parse_chat_messages(
 
         conversation.extend(sub_messages)
 
+    _postprocess_messages(conversation)
+
     return conversation, mm_tracker.all_mm_data()
 
 
@@ -462,41 +483,41 @@ def parse_chat_messages_futures(
 
         conversation.extend(sub_messages)
 
+    _postprocess_messages(conversation)
+
     return conversation, mm_tracker.all_mm_data()
 
 
-def apply_chat_template(
-    tokenizer: AnyTokenizer,
+def apply_hf_chat_template(
+    tokenizer: Union[PreTrainedTokenizer, PreTrainedTokenizerFast],
     conversation: List[ConversationMessage],
     chat_template: Optional[str],
     *,
     tokenize: bool = False,  # Different from HF's default
     **kwargs: Any,
-) -> Union[str, List[int]]:
+) -> str:
     if chat_template is None and tokenizer.chat_template is None:
         raise ValueError(
             "As of transformers v4.44, default chat template is no longer "
             "allowed, so you must provide a chat template if the tokenizer "
             "does not define one.")
 
-    # per the Transformers docs & maintainers, tool call arguments in
-    # assistant-role messages with tool_calls need to be dicts not JSON str -
-    # this is how tool-use chat templates will expect them moving forwards
-    # so, for messages that have tool_calls, parse the string (which we get
-    # from openAI format) to dict
-    for message in conversation:
-        if (message["role"] == "assistant" and "tool_calls" in message
-                and isinstance(message["tool_calls"], list)):
+    return tokenizer.apply_chat_template(
+        conversation=conversation,  # type: ignore[arg-type]
+        chat_template=chat_template,
+        tokenize=tokenize,
+        **kwargs,
+    )
 
-            for i in range(len(message["tool_calls"])):
-                args: str = message["tool_calls"][i]["function"]["arguments"]
-                parsed_args: Dict = json.loads(args)
-                message["tool_calls"][i]["function"]["arguments"] = parsed_args
 
-    prompt = tokenizer.apply_chat_template(
-        conversation=conversation,
+def apply_mistral_chat_template(
+    tokenizer: MistralTokenizer,
+    messages: List[ChatCompletionMessageParam],
+    chat_template: Optional[str],
+    **kwargs: Any,
+) -> List[int]:
+    return tokenizer.apply_chat_template(
+        messages=messages,
         chat_template=chat_template,
-        tokenize=tokenize,
         **kwargs,
     )
-    return prompt

vllm/entrypoints/llm.py

@@ -6,7 +6,8 @@ from tqdm import tqdm
 from vllm.engine.arg_utils import EngineArgs
 from vllm.engine.llm_engine import LLMEngine
 from vllm.entrypoints.chat_utils import (ChatCompletionMessageParam,
-                                         apply_chat_template,
+                                         apply_hf_chat_template,
+                                         apply_mistral_chat_template,
                                          parse_chat_messages)
 from vllm.inputs import PromptInputs, TextPrompt, TokensPrompt
 from vllm.inputs.parse import parse_and_batch_prompt
@@ -19,7 +20,7 @@ from vllm.outputs import EmbeddingRequestOutput, RequestOutput
 from vllm.pooling_params import PoolingParams
 from vllm.prompt_adapter.request import PromptAdapterRequest
 from vllm.sampling_params import SamplingParams
-from vllm.transformers_utils.tokenizer import (AnyTokenizer,
+from vllm.transformers_utils.tokenizer import (AnyTokenizer, MistralTokenizer,
                                                get_cached_tokenizer)
 from vllm.transformers_utils.tokenizer_group import TokenizerGroup
 from vllm.usage.usage_lib import UsageContext
@@ -393,12 +394,21 @@ class LLM:
         conversation, mm_data = parse_chat_messages(messages, model_config,
                                                     tokenizer)
 
-        prompt = apply_chat_template(
-            tokenizer,
-            conversation,
-            chat_template=chat_template,
-            add_generation_prompt=add_generation_prompt,
-        )
+        prompt: Union[str, List[int]]
+        if isinstance(tokenizer, MistralTokenizer):
+            prompt = apply_mistral_chat_template(
+                tokenizer,
+                messages=messages,
+                chat_template=chat_template,
+                add_generation_prompt=add_generation_prompt,
+            )
+        else:
+            prompt = apply_hf_chat_template(
+                tokenizer,
+                conversation=conversation,
+                chat_template=chat_template,
+                add_generation_prompt=add_generation_prompt,
+            )
 
         inputs: PromptInputs
         if is_list_of(prompt, int):

vllm/entrypoints/openai/serving_chat.py

@@ -11,7 +11,8 @@ from fastapi import Request
 from vllm.config import ModelConfig
 from vllm.engine.protocol import AsyncEngineClient
 from vllm.entrypoints.chat_utils import (ConversationMessage,
-                                         apply_chat_template,
+                                         apply_hf_chat_template,
+                                         apply_mistral_chat_template,
                                          load_chat_template,
                                          parse_chat_messages_futures)
 from vllm.entrypoints.logger import RequestLogger
@@ -35,7 +36,7 @@ from vllm.outputs import CompletionOutput, RequestOutput
 from vllm.sequence import Logprob
 from vllm.tracing import (contains_trace_headers, extract_trace_headers,
                           log_tracing_disabled_warning)
-from vllm.transformers_utils.tokenizer import AnyTokenizer
+from vllm.transformers_utils.tokenizer import AnyTokenizer, MistralTokenizer
 from vllm.utils import iterate_with_cancellation, random_uuid
 
 logger = init_logger(__name__)
@@ -121,15 +122,27 @@ class OpenAIServingChat(OpenAIServing):
                 tool.model_dump() for tool in request.tools
             ]
 
-            prompt = apply_chat_template(
-                tokenizer,
-                conversation=conversation,
-                chat_template=request.chat_template or self.chat_template,
-                add_generation_prompt=request.add_generation_prompt,
-                tools=tool_dicts,
-                documents=request.documents,
-                **(request.chat_template_kwargs or {}),
-            )
+            prompt: Union[str, List[int]]
+            if isinstance(tokenizer, MistralTokenizer):
+                prompt = apply_mistral_chat_template(
+                    tokenizer,
+                    messages=request.messages,
+                    chat_template=request.chat_template or self.chat_template,
+                    add_generation_prompt=request.add_generation_prompt,
+                    tools=tool_dicts,
+                    documents=request.documents,
+                    **(request.chat_template_kwargs or {}),
+                )
+            else:
+                prompt = apply_hf_chat_template(
+                    tokenizer,
+                    conversation=conversation,
+                    chat_template=request.chat_template or self.chat_template,
+                    add_generation_prompt=request.add_generation_prompt,
+                    tools=tool_dicts,
+                    documents=request.documents,
+                    **(request.chat_template_kwargs or {}),
+                )
         except Exception as e:
             logger.error("Error in applying chat template from request: %s", e)
             return self.create_error_response(str(e))
@@ -307,11 +320,10 @@ class OpenAIServingChat(OpenAIServing):
                     # Send response to echo the input portion of the
                     # last message
                     if request.echo:
-                        last_msg_content: Optional[str] = ""
-                        if conversation and conversation[-1].get(
-                                "content") and conversation[-1].get(
-                                    "role") == role:
-                            last_msg_content = conversation[-1]["content"]
+                        last_msg_content: str = ""
+                        if conversation and "content" in conversation[
+                                -1] and conversation[-1].get("role") == role:
+                            last_msg_content = conversation[-1]["content"] or ""
 
                         if last_msg_content:
                             for i in range(num_choices):
@@ -659,8 +671,8 @@ class OpenAIServingChat(OpenAIServing):
 
         if request.echo:
             last_msg_content = ""
-            if conversation and conversation[-1].get(
-                    "content") and conversation[-1].get("role") == role:
+            if conversation and "content" in conversation[-1] and conversation[
+                    -1].get("role") == role:
                 last_msg_content = conversation[-1]["content"] or ""
 
             for choice in choices:

vllm/entrypoints/openai/serving_tokenization.py

@@ -2,7 +2,8 @@ from typing import List, Optional, Union
 
 from vllm.config import ModelConfig
 from vllm.engine.protocol import AsyncEngineClient
-from vllm.entrypoints.chat_utils import (apply_chat_template,
+from vllm.entrypoints.chat_utils import (apply_hf_chat_template,
+                                         apply_mistral_chat_template,
                                          load_chat_template,
                                          parse_chat_messages_futures)
 from vllm.entrypoints.logger import RequestLogger
@@ -18,6 +19,7 @@ from vllm.entrypoints.openai.protocol import (DetokenizeRequest,
 from vllm.entrypoints.openai.serving_engine import (LoRAModulePath,
                                                     OpenAIServing)
 from vllm.logger import init_logger
+from vllm.transformers_utils.tokenizer import MistralTokenizer
 from vllm.utils import random_uuid
 
 logger = init_logger(__name__)
@@ -66,6 +68,7 @@ class OpenAIServingTokenization(OpenAIServing):
 
         tokenizer = await self.async_engine_client.get_tokenizer(lora_request)
 
+        prompt: Union[str, List[int]]
         if isinstance(request, TokenizeChatRequest):
             model_config = self.model_config
 
@@ -77,12 +80,20 @@ class OpenAIServingTokenization(OpenAIServing):
                 logger.warning(
                     "Multi-modal inputs are ignored during tokenization")
 
-            prompt = apply_chat_template(
-                tokenizer,
-                conversation=conversation,
-                chat_template=self.chat_template,
-                add_generation_prompt=request.add_generation_prompt,
-            )
+            if isinstance(tokenizer, MistralTokenizer):
+                prompt = apply_mistral_chat_template(
+                    tokenizer,
+                    messages=request.messages,
+                    chat_template=self.chat_template,
+                    add_generation_prompt=request.add_generation_prompt,
+                )
+            else:
+                prompt = apply_hf_chat_template(
+                    tokenizer,
+                    conversation=conversation,
+                    chat_template=self.chat_template,
+                    add_generation_prompt=request.add_generation_prompt,
+                )
         else:
             prompt = request.prompt
 

vllm/transformers_utils/tokenizers/mistral.py

@@ -16,7 +16,7 @@ from mistral_common.tokens.tokenizers.tekken import (SpecialTokenPolicy,
                                                      Tekkenizer)
 
 if TYPE_CHECKING:
-    from vllm.entrypoints.chat_utils import ConversationMessage
+    from vllm.entrypoints.chat_utils import ChatCompletionMessageParam
 
 
 @dataclass
@@ -122,19 +122,19 @@ class MistralTokenizer:
         return []
 
     def encode(self, prompt: str) -> List[int]:
-        # `encode ` should only be used for prompt completion
+        # `encode` should only be used for prompt completion
         # it should never be used for chat_completion.
         # For chat completion use `apply_chat_template`
         return self.tokenizer.encode(prompt, bos=True, eos=False)
 
     def apply_chat_template(self,
-                            conversation: List["ConversationMessage"],
+                            messages: List["ChatCompletionMessageParam"],
                             tools: Optional[Dict[str, Any]] = None,
                             **kwargs) -> List[int]:
         assert tools is None, "`tools` are not yet supported."
 
         request = ChatCompletionRequest(
-            messages=conversation)  # type: ignore[type-var]
+            messages=messages)  # type: ignore[type-var]
         encoded = self.mistral.encode_chat_completion(request)
 
         # encode-decode to get clean prompt