[BugFix][Frontend] Use LoRA tokenizer in OpenAI APIs (#6227)

Co-authored-by: Cyrus Leung <cyrus.tl.leung@gmail.com>

tests/async_engine/test_chat_template.py

 import os
 import pathlib
-from dataclasses import dataclass
 
 import pytest
 
@@ -50,23 +49,9 @@ TEST_MESSAGES = [
 ]
 
 
-@dataclass
-class MockTokenizer:
-    chat_template = None
-
-
-@dataclass
-class MockServingChat:
-    tokenizer: MockTokenizer
-
-
 def test_load_chat_template():
     # Testing chatml template
-    tokenizer = MockTokenizer()
-    mock_serving_chat = MockServingChat(tokenizer)
-    load_chat_template(mock_serving_chat, chat_template=chatml_jinja_path)
-
-    template_content = tokenizer.chat_template
+    template_content = load_chat_template(chat_template=chatml_jinja_path)
 
     # Test assertions
     assert template_content is not None
@@ -78,22 +63,16 @@ def test_load_chat_template():
 def test_no_load_chat_template_filelike():
     # Testing chatml template
     template = "../../examples/does_not_exist"
-    tokenizer = MockTokenizer()
-
-    mock_serving_chat = MockServingChat(tokenizer)
 
     with pytest.raises(ValueError, match="looks like a file path"):
-        load_chat_template(mock_serving_chat, chat_template=template)
+        load_chat_template(chat_template=template)
 
 
 def test_no_load_chat_template_literallike():
     # Testing chatml template
     template = "{{ messages }}"
-    tokenizer = MockTokenizer()
 
-    mock_serving_chat = MockServingChat(tokenizer)
-    load_chat_template(mock_serving_chat, chat_template=template)
-    template_content = tokenizer.chat_template
+    template_content = load_chat_template(chat_template=template)
 
     assert template_content == template
 
@@ -105,8 +84,7 @@ def test_get_gen_prompt(model, template, add_generation_prompt,
                         expected_output):
     # Initialize the tokenizer
     tokenizer = get_tokenizer(tokenizer_name=model)
-    mock_serving_chat = MockServingChat(tokenizer)
-    load_chat_template(mock_serving_chat, chat_template=template)
+    template_content = load_chat_template(chat_template=template)
 
     # Create a mock request object using keyword arguments
     mock_request = ChatCompletionRequest(
@@ -118,7 +96,8 @@ def test_get_gen_prompt(model, template, add_generation_prompt,
     result = tokenizer.apply_chat_template(
         conversation=mock_request.messages,
         tokenize=False,
-        add_generation_prompt=mock_request.add_generation_prompt)
+        add_generation_prompt=mock_request.add_generation_prompt,
+        chat_template=mock_request.chat_template or template_content)
 
     # Test assertion
     assert result == expected_output, (

tests/entrypoints/openai/test_chat.py

@@ -7,11 +7,11 @@ import jsonschema
 import openai  # use the official client for correctness check
 import pytest
 import torch
-# downloading lora to test lora requests
-from huggingface_hub import snapshot_download
 from openai import BadRequestError
 
 from ...utils import RemoteOpenAIServer
+from .test_completion import zephyr_lora_added_tokens_files  # noqa: F401
+from .test_completion import zephyr_lora_files  # noqa: F401
 
 # any model with a chat template should work here
 MODEL_NAME = "HuggingFaceH4/zephyr-7b-beta"
@@ -21,12 +21,7 @@ LORA_NAME = "typeof/zephyr-7b-beta-lora"
 
 
 @pytest.fixture(scope="module")
-def zephyr_lora_files():
-    return snapshot_download(repo_id=LORA_NAME)
-
-
-@pytest.fixture(scope="module")
-def server(zephyr_lora_files):
+def server(zephyr_lora_files, zephyr_lora_added_tokens_files):  # noqa: F811
     args = [
         # use half precision for speed and memory savings in CI environment
         "--dtype",
@@ -38,7 +33,7 @@ def server(zephyr_lora_files):
         "--enable-lora",
         "--lora-modules",
         f"zephyr-lora={zephyr_lora_files}",
-        f"zephyr-lora2={zephyr_lora_files}",
+        f"zephyr-lora2={zephyr_lora_added_tokens_files}",
         "--max-lora-rank",
         "64",
         "--max-cpu-loras",

tests/entrypoints/openai/test_completion.py

 # imports for guided decoding tests
 import json
 import re
+import shutil
+from tempfile import TemporaryDirectory
 from typing import List
 
 import jsonschema
@@ -9,6 +11,7 @@ import pytest
 # downloading lora to test lora requests
 from huggingface_hub import snapshot_download
 from openai import BadRequestError
+from transformers import AutoTokenizer
 
 from vllm.transformers_utils.tokenizer import get_tokenizer
 
@@ -30,13 +33,29 @@ def zephyr_lora_files():
     return snapshot_download(repo_id=LORA_NAME)
 
 
+@pytest.fixture(scope="module")
+def zephyr_lora_added_tokens_files(zephyr_lora_files):
+    tmp_dir = TemporaryDirectory()
+    tmp_model_dir = f"{tmp_dir.name}/zephyr"
+    shutil.copytree(zephyr_lora_files, tmp_model_dir)
+    tokenizer = AutoTokenizer.from_pretrained(MODEL_NAME)
+    # Copy tokenizer to adapter and add some unique tokens
+    # 32000, 32001, 32002
+    added = tokenizer.add_tokens(["vllm1", "vllm2", "vllm3"],
+                                 special_tokens=True)
+    assert added == 3
+    tokenizer.save_pretrained(tmp_model_dir)
+    yield tmp_model_dir
+    tmp_dir.cleanup()
+
+
 @pytest.fixture(scope="module")
 def zephyr_pa_files():
     return snapshot_download(repo_id=PA_NAME)
 
 
 @pytest.fixture(scope="module")
-def server(zephyr_lora_files, zephyr_pa_files):
+def server(zephyr_lora_files, zephyr_lora_added_tokens_files, zephyr_pa_files):
     args = [
         # use half precision for speed and memory savings in CI environment
         "--dtype",
@@ -50,7 +69,7 @@ def server(zephyr_lora_files, zephyr_pa_files):
         "--enable-lora",
         "--lora-modules",
         f"zephyr-lora={zephyr_lora_files}",
-        f"zephyr-lora2={zephyr_lora_files}",
+        f"zephyr-lora2={zephyr_lora_added_tokens_files}",
         "--max-lora-rank",
         "64",
         "--max-cpu-loras",
@@ -111,6 +130,34 @@ async def test_single_completion(client: openai.AsyncOpenAI, model_name: str,
     assert len(completion.choices[0].text) >= 1
 
 
+@pytest.mark.asyncio
+async def test_added_lora_tokens(client: openai.AsyncOpenAI):
+    # test using token IDs
+    completion = await client.completions.create(
+        model="zephyr-lora2",
+        prompt=[0, 0, 32000, 32001, 32002],
+        echo=True,
+        max_tokens=5,
+        temperature=0.0,
+    )
+    # Added tokens should appear in tokenized prompt
+    assert completion.choices[0].text.startswith("<unk><unk>vllm1vllm2vllm3")
+
+
+@pytest.mark.asyncio
+async def test_added_lora_tokens_base_model(client: openai.AsyncOpenAI):
+    # test using token IDs
+    completion = await client.completions.create(
+        model=MODEL_NAME,
+        prompt=[0, 0, 32000, 32001, 32002],
+        echo=True,
+        max_tokens=5,
+        temperature=0.0,
+    )
+    # Added tokens should not appear in tokenized prompt
+    assert "vllm" not in completion.choices[0].text
+
+
 @pytest.mark.asyncio
 @pytest.mark.parametrize(
     # first test base model, then test loras, then test prompt adapters

tests/entrypoints/openai/test_serving_chat.py

@@ -38,5 +38,4 @@ async def _async_serving_chat_init():
 
 def test_async_serving_chat_init():
     serving_completion = asyncio.run(_async_serving_chat_init())
-    assert serving_completion.tokenizer is not None
-    assert serving_completion.tokenizer.chat_template == CHAT_TEMPLATE
+    assert serving_completion.chat_template == CHAT_TEMPLATE

tests/entrypoints/openai/test_tokenization.py

@@ -5,13 +5,15 @@ import requests
 from vllm.transformers_utils.tokenizer import get_tokenizer
 
 from ...utils import RemoteOpenAIServer
+from .test_completion import zephyr_lora_added_tokens_files  # noqa: F401
+from .test_completion import zephyr_lora_files  # noqa: F401
 
 # any model with a chat template should work here
 MODEL_NAME = "HuggingFaceH4/zephyr-7b-beta"
 
 
 @pytest.fixture(scope="module")
-def server():
+def server(zephyr_lora_added_tokens_files: str):  # noqa: F811
     args = [
         # use half precision for speed and memory savings in CI environment
         "--dtype",
@@ -21,12 +23,25 @@ def server():
         "--enforce-eager",
         "--max-num-seqs",
         "128",
+        # lora config
+        "--enable-lora",
+        "--lora-modules",
+        f"zephyr-lora2={zephyr_lora_added_tokens_files}",
+        "--max-lora-rank",
+        "64",
     ]
 
     with RemoteOpenAIServer(MODEL_NAME, args) as remote_server:
         yield remote_server
 
 
+@pytest.fixture(scope="module")
+def tokenizer_name(model_name: str,
+                   zephyr_lora_added_tokens_files: str):  # noqa: F811
+    return zephyr_lora_added_tokens_files if (
+        model_name == "zephyr-lora2") else model_name
+
+
 @pytest.fixture(scope="module")
 def client(server):
     return server.get_async_client()
@@ -34,16 +49,18 @@ def client(server):
 
 @pytest.mark.asyncio
 @pytest.mark.parametrize(
-    "model_name",
-    [MODEL_NAME],
+    "model_name,tokenizer_name",
+    [(MODEL_NAME, MODEL_NAME), ("zephyr-lora2", "zephyr-lora2")],
+    indirect=["tokenizer_name"],
 )
 async def test_tokenize_completions(client: openai.AsyncOpenAI,
-                                    model_name: str):
+                                    model_name: str, tokenizer_name: str):
     base_url = str(client.base_url)[:-3].strip("/")
-    tokenizer = get_tokenizer(tokenizer_name=model_name, tokenizer_mode="fast")
+    tokenizer = get_tokenizer(tokenizer_name=tokenizer_name,
+                              tokenizer_mode="fast")
 
     for add_special in [False, True]:
-        prompt = "This is a test prompt."
+        prompt = "vllm1 This is a test prompt."
         tokens = tokenizer.encode(prompt, add_special_tokens=add_special)
 
         response = requests.post(base_url + "/tokenize",
@@ -63,12 +80,15 @@ async def test_tokenize_completions(client: openai.AsyncOpenAI,
 
 @pytest.mark.asyncio
 @pytest.mark.parametrize(
-    "model_name",
-    [MODEL_NAME],
+    "model_name,tokenizer_name",
+    [(MODEL_NAME, MODEL_NAME), ("zephyr-lora2", "zephyr-lora2")],
+    indirect=["tokenizer_name"],
 )
-async def test_tokenize_chat(client: openai.AsyncOpenAI, model_name: str):
+async def test_tokenize_chat(client: openai.AsyncOpenAI, model_name: str,
+                             tokenizer_name: str):
     base_url = str(client.base_url)[:-3].strip("/")
-    tokenizer = get_tokenizer(tokenizer_name=model_name, tokenizer_mode="fast")
+    tokenizer = get_tokenizer(tokenizer_name=tokenizer_name,
+                              tokenizer_mode="fast")
 
     for add_generation in [False, True]:
         for add_special in [False, True]:
@@ -80,7 +100,7 @@ async def test_tokenize_chat(client: openai.AsyncOpenAI, model_name: str):
                 "content": "Nice to meet you!"
             }, {
                 "role": "user",
-                "content": "Can I ask a question?"
+                "content": "Can I ask a question? vllm1"
             }]
 
             prompt = tokenizer.apply_chat_template(
@@ -108,16 +128,20 @@ async def test_tokenize_chat(client: openai.AsyncOpenAI, model_name: str):
 
 @pytest.mark.asyncio
 @pytest.mark.parametrize(
-    "model_name",
-    [MODEL_NAME],
+    "model_name,tokenizer_name",
+    [(MODEL_NAME, MODEL_NAME), ("zephyr-lora2", "zephyr-lora2")],
+    indirect=["tokenizer_name"],
 )
-async def test_detokenize(client: openai.AsyncOpenAI, model_name: str):
+async def test_detokenize(client: openai.AsyncOpenAI, model_name: str,
+                          tokenizer_name: str):
     base_url = str(client.base_url)[:-3].strip("/")
-    tokenizer = get_tokenizer(tokenizer_name=model_name, tokenizer_mode="fast")
+    tokenizer = get_tokenizer(tokenizer_name=tokenizer_name,
+                              tokenizer_mode="fast")
 
-    prompt = "This is a test prompt."
+    prompt = "This is a test prompt. vllm1"
     tokens = tokenizer.encode(prompt, add_special_tokens=False)
 
+    print(f"CALLING {base_url} FOR {model_name}")
     response = requests.post(base_url + "/detokenize",
                              json={
                                  "model": model_name,

vllm/engine/async_llm_engine.py

@@ -480,11 +480,16 @@ class AsyncLLMEngine:
         self.set_errored(exc)
         self._request_tracker.propagate_exception(exc)
 
-    async def get_tokenizer(self) -> "PreTrainedTokenizer":
+    async def get_tokenizer(
+        self,
+        lora_request: Optional[LoRARequest] = None,
+    ) -> "PreTrainedTokenizer":
         if self.engine_use_ray:
-            return await self.engine.get_tokenizer.remote()  # type: ignore
-        else:
-            return self.engine.get_tokenizer()
+            return await self.engine.get_tokenizer.remote(  # type: ignore
+                lora_request)
+
+        return await (self.engine.get_tokenizer_group().
+                      get_lora_tokenizer_async(lora_request))
 
     def start_background_loop(self) -> None:
         """Start the background loop."""

vllm/engine/llm_engine.py

@@ -455,8 +455,11 @@ class LLMEngine:
 
         return self.tokenizer
 
-    def get_tokenizer(self) -> "PreTrainedTokenizer":
-        return self.get_tokenizer_group().get_lora_tokenizer(None)
+    def get_tokenizer(
+            self,
+            lora_request: Optional[LoRARequest] = None
+    ) -> "PreTrainedTokenizer":
+        return self.get_tokenizer_group().get_lora_tokenizer(lora_request)
 
     def get_tokenizer_for_seq(self,
                               sequence: Sequence) -> "PreTrainedTokenizer":

vllm/entrypoints/openai/api_server.py

@@ -257,7 +257,8 @@ def run_server(args, llm_engine=None):
     openai_serving_embedding = OpenAIServingEmbedding(engine, model_config,
                                                       served_model_names)
     openai_serving_tokenization = OpenAIServingTokenization(
-        engine, model_config, served_model_names, args.chat_template)
+        engine, model_config, served_model_names, args.lora_modules,
+        args.chat_template)
     app.root_path = args.root_path
 
     logger.info("Available routes are:")

vllm/entrypoints/openai/chat_utils.py

@@ -5,10 +5,11 @@ from typing import Awaitable, Iterable, List, Optional, TypedDict, cast, final
 
 from openai.types.chat import (ChatCompletionContentPartImageParam,
                                ChatCompletionContentPartTextParam)
+from transformers import PreTrainedTokenizer
 
+from vllm.config import ModelConfig
 from vllm.entrypoints.openai.protocol import (ChatCompletionContentPartParam,
                                               ChatCompletionMessageParam)
-from vllm.entrypoints.openai.serving_engine import OpenAIServing
 from vllm.logger import init_logger
 from vllm.multimodal import MultiModalDataDict
 from vllm.multimodal.utils import async_get_and_parse_image
@@ -29,13 +30,12 @@ class ChatMessageParseResult:
         default_factory=list)
 
 
-def load_chat_template(engine: OpenAIServing, chat_template: Optional[str]):
-    tokenizer = engine.tokenizer
-
-    if chat_template is not None:
+def load_chat_template(chat_template: Optional[str]) -> Optional[str]:
+    if chat_template is None:
+        return None
     try:
         with open(chat_template, "r") as f:
-                tokenizer.chat_template = f.read()
+            resolved_chat_template = f.read()
     except OSError as e:
         JINJA_CHARS = "{}\n"
         if not any(c in chat_template for c in JINJA_CHARS):
@@ -46,23 +46,18 @@ def load_chat_template(engine: OpenAIServing, chat_template: Optional[str]):
 
         # If opening a file fails, set chat template to be args to
         # ensure we decode so our escape are interpreted correctly
-            tokenizer.chat_template = codecs.decode(chat_template,
-                                                    "unicode_escape")
-
-        logger.info("Using supplied chat template:\n%s",
-                    tokenizer.chat_template)
-    elif tokenizer.chat_template is not None:
-        logger.info("Using default chat template:\n%s",
-                    tokenizer.chat_template)
-    else:
-        logger.warning("No chat template provided. Chat API will not work.")
+        resolved_chat_template = codecs.decode(chat_template, "unicode_escape")
+
+    logger.info("Using supplied chat template:\n%s", resolved_chat_template)
+    return resolved_chat_template
 
 
 @lru_cache(maxsize=None)
-def _image_token_str(engine: OpenAIServing) -> Optional[str]:
+def _image_token_str(model_config: ModelConfig,
+                     tokenizer: PreTrainedTokenizer) -> Optional[str]:
     # TODO: Let user specify how to insert image tokens into prompt
     # (similar to chat template)
-    model_type = engine.model_config.hf_config.model_type
+    model_type = model_config.hf_config.model_type
     if model_type == "phi3_v":
         # Workaround since this token is not defined in the tokenizer
         return "<|image_1|>"
@@ -70,17 +65,14 @@ def _image_token_str(engine: OpenAIServing) -> Optional[str]:
         # These models do not use image tokens in the prompt
         return None
     if model_type.startswith("llava"):
-        return engine.tokenizer.decode(
-            engine.model_config.hf_config.image_token_index)
+        return tokenizer.decode(model_config.hf_config.image_token_index)
 
-    else:
     raise TypeError("Unknown model type: {model_type}")
 
 
 # TODO: Let user specify how to insert image tokens into prompt
 # (similar to chat template)
-def _get_full_image_text_prompt(engine: OpenAIServing, image_token_str: str,
-                                text_prompt: str) -> str:
+def _get_full_image_text_prompt(image_token_str: str, text_prompt: str) -> str:
     """Combine image and text prompts for vision language model"""
 
     # NOTE: For now we assume all model architectures use the same
@@ -89,9 +81,10 @@ def _get_full_image_text_prompt(engine: OpenAIServing, image_token_str: str,
 
 
 def _parse_chat_message_content_parts(
-    engine: OpenAIServing,
     role: str,
     parts: Iterable[ChatCompletionContentPartParam],
+    model_config: ModelConfig,
+    tokenizer: PreTrainedTokenizer,
 ) -> ChatMessageParseResult:
     texts: List[str] = []
     mm_futures: List[Awaitable[MultiModalDataDict]] = []
@@ -122,7 +115,7 @@ def _parse_chat_message_content_parts(
     text_prompt = "\n".join(texts)
 
     if mm_futures:
-        image_token_str = _image_token_str(engine)
+        image_token_str = _image_token_str(model_config, tokenizer)
         if image_token_str is not None:
             if image_token_str in text_prompt:
                 logger.warning(
@@ -130,7 +123,6 @@ def _parse_chat_message_content_parts(
                     "Skipping prompt formatting.")
             else:
                 text_prompt = _get_full_image_text_prompt(
-                    engine,
                     image_token_str=image_token_str,
                     text_prompt=text_prompt,
                 )
@@ -141,8 +133,9 @@ def _parse_chat_message_content_parts(
 
 
 def parse_chat_message_content(
-    engine: OpenAIServing,
     message: ChatCompletionMessageParam,
+    model_config: ModelConfig,
+    tokenizer: PreTrainedTokenizer,
 ) -> ChatMessageParseResult:
     role = message["role"]
     content = message.get("content")
@@ -153,4 +146,5 @@ def parse_chat_message_content(
         messages = [ConversationMessage(role=role, content=content)]
         return ChatMessageParseResult(messages=messages, mm_futures=[])
 
-    return _parse_chat_message_content_parts(engine, role, content)
+    return _parse_chat_message_content_parts(role, content, model_config,
+                                             tokenizer)

vllm/entrypoints/openai/serving_chat.py

@@ -5,6 +5,7 @@ from typing import Sequence as GenericSequence
 from typing import Union
 
 from fastapi import Request
+from transformers import PreTrainedTokenizer
 
 from vllm.config import ModelConfig
 from vllm.engine.async_llm_engine import AsyncLLMEngine
@@ -49,7 +50,9 @@ class OpenAIServingChat(OpenAIServing):
                          lora_modules=lora_modules)
 
         self.response_role = response_role
-        load_chat_template(self, chat_template)
+
+        # If this is None we use the tokenizer's default chat template
+        self.chat_template = load_chat_template(chat_template)
 
     async def create_chat_completion(
         self,
@@ -71,11 +74,15 @@ class OpenAIServingChat(OpenAIServing):
             return error_check_ret
 
         try:
+            _, lora_request = self._maybe_get_adapter(request)
+            tokenizer = await self.engine.get_tokenizer(lora_request)
+
             conversation: List[ConversationMessage] = []
             mm_futures: List[Awaitable[MultiModalDataDict]] = []
 
             for msg in request.messages:
-                chat_parsed_result = parse_chat_message_content(self, msg)
+                chat_parsed_result = parse_chat_message_content(
+                    msg, self.model_config, tokenizer)
 
                 conversation.extend(chat_parsed_result.messages)
                 mm_futures.extend(chat_parsed_result.mm_futures)
@@ -84,13 +91,13 @@ class OpenAIServingChat(OpenAIServing):
                 tool.model_dump() for tool in request.tools
             ]
 
-            prompt = self.tokenizer.apply_chat_template(
+            prompt = tokenizer.apply_chat_template(
                 conversation=conversation,
                 tokenize=False,
                 add_generation_prompt=request.add_generation_prompt,
                 tools=tool_dicts,
                 documents=request.documents,
-                chat_template=request.chat_template,
+                chat_template=request.chat_template or self.chat_template,
                 **(request.chat_template_kwargs or {}),
             )
         except Exception as e:
@@ -112,19 +119,19 @@ class OpenAIServingChat(OpenAIServing):
         request_id = f"cmpl-{random_uuid()}"
         try:
             # Tokenize/detokenize depending on prompt format (string/token list)
-            prompt_ids, prompt_text = self._validate_prompt_and_tokenize(
+            prompt_ids, prompt_text = await self._validate_prompt_and_tokenize(
                 request,
+                tokenizer,
                 prompt=prompt,
                 add_special_tokens=request.add_special_tokens)
             sampling_params = request.to_sampling_params()
-            _, lora_request = self._maybe_get_adapter(request)
             decoding_config = await self.engine.get_decoding_config()
             guided_decoding_backend = request.guided_decoding_backend \
                 or decoding_config.guided_decoding_backend
             guided_decode_logits_processor = (
-                await get_guided_decoding_logits_processor(
-                    guided_decoding_backend, request, await
-                    self.engine.get_tokenizer()))
+                await
+                get_guided_decoding_logits_processor(guided_decoding_backend,
+                                                     request, tokenizer))
             if guided_decode_logits_processor:
                 if sampling_params.logits_processors is None:
                     sampling_params.logits_processors = []
@@ -158,12 +165,12 @@ class OpenAIServingChat(OpenAIServing):
         # Streaming response
         if request.stream:
             return self.chat_completion_stream_generator(
-                request, result_generator, request_id, conversation)
+                request, result_generator, request_id, conversation, tokenizer)
         else:
             try:
                 return await self.chat_completion_full_generator(
                     request, raw_request, result_generator, request_id,
-                    conversation)
+                    conversation, tokenizer)
             except ValueError as e:
                 # TODO: Use a vllm-specific Validation Error
                 return self.create_error_response(str(e))
@@ -175,9 +182,12 @@ class OpenAIServingChat(OpenAIServing):
             return request.messages[-1]["role"]
 
     async def chat_completion_stream_generator(
-            self, request: ChatCompletionRequest,
-            result_generator: AsyncIterator[RequestOutput], request_id: str,
-            conversation: List[ConversationMessage]
+        self,
+        request: ChatCompletionRequest,
+        result_generator: AsyncIterator[RequestOutput],
+        request_id: str,
+        conversation: List[ConversationMessage],
+        tokenizer: PreTrainedTokenizer,
     ) -> AsyncGenerator[str, None]:
         model_name = self.served_model_names[0]
         created_time = int(time.time())
@@ -264,6 +274,7 @@ class OpenAIServingChat(OpenAIServing):
                         logprobs = self._create_chat_logprobs(
                             token_ids=delta_token_ids,
                             top_logprobs=out_logprobs,
+                            tokenizer=tokenizer,
                             num_output_top_logprobs=request.top_logprobs,
                         )
                     else:
@@ -352,9 +363,13 @@ class OpenAIServingChat(OpenAIServing):
         yield "data: [DONE]\n\n"
 
     async def chat_completion_full_generator(
-        self, request: ChatCompletionRequest, raw_request: Optional[Request],
-        result_generator: AsyncIterator[RequestOutput], request_id: str,
-        conversation: List[ConversationMessage]
+        self,
+        request: ChatCompletionRequest,
+        raw_request: Optional[Request],
+        result_generator: AsyncIterator[RequestOutput],
+        request_id: str,
+        conversation: List[ConversationMessage],
+        tokenizer: PreTrainedTokenizer,
     ) -> Union[ErrorResponse, ChatCompletionResponse]:
 
         model_name = self.served_model_names[0]
@@ -382,6 +397,7 @@ class OpenAIServingChat(OpenAIServing):
                     token_ids=token_ids,
                     top_logprobs=out_logprobs,
                     num_output_top_logprobs=request.top_logprobs,
+                    tokenizer=tokenizer,
                 )
             else:
                 logprobs = None
@@ -436,16 +452,14 @@ class OpenAIServingChat(OpenAIServing):
         return response
 
     def _get_top_logprobs(
-            self, logprobs: Dict[int, Logprob],
-            top_logprobs: Optional[int]) -> List[ChatCompletionLogProb]:
+            self, logprobs: Dict[int, Logprob], top_logprobs: Optional[int],
+            tokenizer: PreTrainedTokenizer) -> List[ChatCompletionLogProb]:
         return [
             ChatCompletionLogProb(
-                token=self._get_decoded_token(p[1], p[0]),
+                token=(token := self._get_decoded_token(p[1], p[0],
+                                                        tokenizer)),
                 logprob=max(p[1].logprob, -9999.0),
-                bytes=list(
-                    self._get_decoded_token(p[1],
-                                            p[0]).encode("utf-8",
-                                                         errors="replace")))
+                bytes=list(token.encode("utf-8", errors="replace")))
             for i, p in enumerate(logprobs.items())
             if top_logprobs and i < top_logprobs
         ]
@@ -454,6 +468,7 @@ class OpenAIServingChat(OpenAIServing):
         self,
         token_ids: GenericSequence[int],
         top_logprobs: GenericSequence[Optional[Dict[int, Logprob]]],
+        tokenizer: PreTrainedTokenizer,
         num_output_top_logprobs: Optional[int] = None,
     ) -> ChatCompletionLogProbs:
         """Create OpenAI-style logprobs."""
@@ -463,12 +478,11 @@ class OpenAIServingChat(OpenAIServing):
         for i, token_id in enumerate(token_ids):
             step_top_logprobs = top_logprobs[i]
             if step_top_logprobs is None:
+                token = tokenizer.decode(token_id)
                 logprobs_content.append(
                     ChatCompletionLogProbsContent(
-                        token=self.tokenizer.decode(token_id),
-                        bytes=list(
-                            self.tokenizer.decode(token_id).encode(
-                                "utf-8", errors="replace"))))
+                        token=token,
+                        bytes=list(token.encode("utf-8", errors="replace"))))
             else:
                 logprobs_content.append(
                     ChatCompletionLogProbsContent(
@@ -479,6 +493,7 @@ class OpenAIServingChat(OpenAIServing):
                             step_top_logprobs[token_id].decoded_token.encode(
                                 "utf-8", errors="replace")),
                         top_logprobs=self._get_top_logprobs(
-                            step_top_logprobs, num_output_top_logprobs)))
+                            step_top_logprobs, num_output_top_logprobs,
+                            tokenizer)))
 
         return ChatCompletionLogProbs(content=logprobs_content)

vllm/entrypoints/openai/serving_completion.py

@@ -5,6 +5,7 @@ from typing import Sequence as GenericSequence
 from typing import Tuple
 
 from fastapi import Request
+from transformers import PreTrainedTokenizer
 
 from vllm.config import ModelConfig
 from vllm.engine.async_llm_engine import AsyncLLMEngine
@@ -100,20 +101,22 @@ class OpenAIServingCompletion(OpenAIServing):
         # Schedule the request and get the result generator.
         generators: List[AsyncIterator[RequestOutput]] = []
         try:
-            sampling_params = request.to_sampling_params()
             adapter_type, adapter_request = self._maybe_get_adapter(request)
             lora_request, prompt_adapter_request = None, None
             if adapter_type == 'LoRA':
                 lora_request, prompt_adapter_request = adapter_request, None
             elif adapter_type == 'PromptAdapter':
                 lora_request, prompt_adapter_request = None, adapter_request
+            tokenizer = await self.engine.get_tokenizer(lora_request)
+
+            sampling_params = request.to_sampling_params()
             decoding_config = await self.engine.get_decoding_config()
             guided_decoding_backend = request.guided_decoding_backend \
                 or decoding_config.guided_decoding_backend
             guided_decode_logit_processor = (
-                await get_guided_decoding_logits_processor(
-                    guided_decoding_backend, request, await
-                    self.engine.get_tokenizer()))
+                await
+                get_guided_decoding_logits_processor(guided_decoding_backend,
+                                                     request, tokenizer))
             if guided_decode_logit_processor is not None:
                 if sampling_params.logits_processors is None:
                     sampling_params.logits_processors = []
@@ -122,18 +125,13 @@ class OpenAIServingCompletion(OpenAIServing):
             prompt_is_tokens, prompts = parse_prompt_format(request.prompt)
 
             for i, prompt in enumerate(prompts):
-                if prompt_is_tokens:
-                    prompt_formats = self._validate_prompt_and_tokenize(
-                        request,
-                        prompt_ids=prompt,
-                        truncate_prompt_tokens=sampling_params.
-                        truncate_prompt_tokens)
-                else:
-                    prompt_formats = self._validate_prompt_and_tokenize(
+                prompt_arg = "prompt_ids" if prompt_is_tokens else "prompt"
+                prompt_formats = await self._validate_prompt_and_tokenize(
                     request,
-                        prompt=prompt,
+                    tokenizer,
                     truncate_prompt_tokens=sampling_params.
-                        truncate_prompt_tokens)
+                    truncate_prompt_tokens,
+                    **{prompt_arg: prompt})
                 prompt_ids, prompt_text = prompt_formats
 
                 is_tracing_enabled = await self.engine.is_tracing_enabled()
@@ -179,7 +177,8 @@ class OpenAIServingCompletion(OpenAIServing):
                                                     request_id,
                                                     created_time,
                                                     model_name,
-                                                    num_prompts=len(prompts))
+                                                    num_prompts=len(prompts),
+                                                    tokenizer=tokenizer)
 
         # Non-streaming response
         final_res_batch: List[Optional[RequestOutput]] = [None] * len(prompts)
@@ -191,7 +190,8 @@ class OpenAIServingCompletion(OpenAIServing):
                     return self.create_error_response("Client disconnected")
                 final_res_batch[i] = res
             response = self.request_output_to_completion_response(
-                final_res_batch, request, request_id, created_time, model_name)
+                final_res_batch, request, request_id, created_time, model_name,
+                tokenizer)
         except ValueError as e:
             # TODO: Use a vllm-specific Validation Error
             return self.create_error_response(str(e))
@@ -218,6 +218,7 @@ class OpenAIServingCompletion(OpenAIServing):
         created_time: int,
         model_name: str,
         num_prompts: int,
+        tokenizer: PreTrainedTokenizer,
     ) -> AsyncGenerator[str, None]:
         assert request.n is not None
         previous_texts = [""] * request.n * num_prompts
@@ -268,6 +269,7 @@ class OpenAIServingCompletion(OpenAIServing):
                             token_ids=delta_token_ids,
                             top_logprobs=out_logprobs,
                             num_output_top_logprobs=request.logprobs,
+                            tokenizer=tokenizer,
                             initial_text_offset=len(previous_texts[i]),
                         )
                     else:
@@ -336,6 +338,7 @@ class OpenAIServingCompletion(OpenAIServing):
         request_id: str,
         created_time: int,
         model_name: str,
+        tokenizer: PreTrainedTokenizer,
     ) -> CompletionResponse:
         choices: List[CompletionResponseChoice] = []
         num_prompt_tokens = 0
@@ -367,6 +370,7 @@ class OpenAIServingCompletion(OpenAIServing):
                     logprobs = self._create_completion_logprobs(
                         token_ids=token_ids,
                         top_logprobs=out_logprobs,
+                        tokenizer=tokenizer,
                         num_output_top_logprobs=request.logprobs,
                     )
                 else:
@@ -404,6 +408,7 @@ class OpenAIServingCompletion(OpenAIServing):
         token_ids: GenericSequence[int],
         top_logprobs: GenericSequence[Optional[Dict[int, Logprob]]],
         num_output_top_logprobs: int,
+        tokenizer: PreTrainedTokenizer,
         initial_text_offset: int = 0,
     ) -> CompletionLogProbs:
         """Create logprobs for OpenAI Completion API."""
@@ -417,13 +422,13 @@ class OpenAIServingCompletion(OpenAIServing):
         for i, token_id in enumerate(token_ids):
             step_top_logprobs = top_logprobs[i]
             if step_top_logprobs is None:
-                token = self.tokenizer.decode(token_id)
+                token = tokenizer.decode(token_id)
                 out_tokens.append(token)
                 out_token_logprobs.append(None)
                 out_top_logprobs.append(None)
             else:
                 token = self._get_decoded_token(step_top_logprobs[token_id],
-                                                token_id)
+                                                token_id, tokenizer)
                 token_logprob = max(step_top_logprobs[token_id].logprob,
                                     -9999.0)
                 out_tokens.append(token)
@@ -436,7 +441,7 @@ class OpenAIServingCompletion(OpenAIServing):
                 out_top_logprobs.append({
                     # Convert float("-inf") to the
                     # JSON-serializable float that OpenAI uses
-                    self._get_decoded_token(top_lp[1], top_lp[0]):
+                    self._get_decoded_token(top_lp[1], top_lp[0], tokenizer):
                     max(top_lp[1].logprob, -9999.0)
                     for i, top_lp in enumerate(step_top_logprobs.items())
                     if num_output_top_logprobs >= i

vllm/entrypoints/openai/serving_embedding.py

@@ -89,14 +89,11 @@ class OpenAIServingEmbedding(OpenAIServing):
             prompt_is_tokens, prompts = parse_prompt_format(request.input)
             pooling_params = request.to_pooling_params()
 
+            tokenizer = await self.engine.get_tokenizer()
             for i, prompt in enumerate(prompts):
-                if prompt_is_tokens:
-                    prompt_formats = self._validate_prompt_and_tokenize(
-                        request, prompt_ids=prompt)
-                else:
-                    prompt_formats = self._validate_prompt_and_tokenize(
-                        request, prompt=prompt)
-
+                prompt_arg = "prompt_ids" if prompt_is_tokens else "prompt"
+                prompt_formats = await self._validate_prompt_and_tokenize(
+                    request, tokenizer, **{prompt_arg: prompt})
                 prompt_ids, prompt_text = prompt_formats
 
                 generator = self.engine.encode(

vllm/entrypoints/openai/serving_engine.py

@@ -5,6 +5,7 @@ from http import HTTPStatus
 from typing import Any, Dict, List, Optional, Tuple, Union
 
 from pydantic import Field
+from transformers import PreTrainedTokenizer
 from typing_extensions import Annotated
 
 from vllm.config import ModelConfig
@@ -19,7 +20,6 @@ from vllm.logger import init_logger
 from vllm.lora.request import LoRARequest
 from vllm.prompt_adapter.request import PromptAdapterRequest
 from vllm.sequence import Logprob
-from vllm.transformers_utils.tokenizer import get_tokenizer
 
 logger = init_logger(__name__)
 
@@ -52,14 +52,6 @@ class OpenAIServing:
         self.model_config = model_config
         self.max_model_len = model_config.max_model_len
 
-        # A separate tokenizer to map token IDs to strings.
-        self.tokenizer = get_tokenizer(
-            model_config.tokenizer,
-            tokenizer_mode=model_config.tokenizer_mode,
-            tokenizer_revision=model_config.tokenizer_revision,
-            trust_remote_code=model_config.trust_remote_code,
-            truncation_side="left")
-
         self.served_model_names = served_model_names
 
         self.lora_requests = []
@@ -154,7 +146,8 @@ class OpenAIServing:
 
     def _maybe_get_adapter(
         self, request: Union[CompletionRequest, ChatCompletionRequest,
-                             EmbeddingRequest]
+                             EmbeddingRequest, TokenizeRequest,
+                             DetokenizeRequest]
     ) -> Tuple[Optional[str], Optional[Union[LoRARequest,
                                              PromptAdapterRequest]]]:
         if request.model in self.served_model_names:
@@ -168,11 +161,12 @@ class OpenAIServing:
         # if _check_model has been called earlier, this will be unreachable
         raise ValueError(f"The model `{request.model}` does not exist.")
 
-    def _validate_prompt_and_tokenize(
+    async def _validate_prompt_and_tokenize(
             self,
             request: Union[ChatCompletionRequest, CompletionRequest,
                            DetokenizeRequest, EmbeddingRequest,
                            TokenizeRequest],
+            tokenizer: "PreTrainedTokenizer",
             prompt: Optional[str] = None,
             prompt_ids: Optional[List[int]] = None,
             truncate_prompt_tokens: Optional[Annotated[int,
@@ -181,7 +175,7 @@ class OpenAIServing:
     ) -> Tuple[List[int], str]:
         if not (prompt or prompt_ids):
             raise ValueError("Either prompt or prompt_ids should be provided.")
-        if (prompt and prompt_ids):
+        if prompt and prompt_ids:
             raise ValueError(
                 "Only one of prompt or prompt_ids should be provided.")
 
@@ -200,14 +194,14 @@ class OpenAIServing:
                     "truncation": True,
                     "max_length": truncate_prompt_tokens,
                 })
-            input_ids = self.tokenizer(prompt, **tokenizer_kwargs).input_ids
+            input_ids = tokenizer(prompt, **tokenizer_kwargs).input_ids
         elif truncate_prompt_tokens is not None:
             input_ids = prompt_ids[-truncate_prompt_tokens:]
         else:
             input_ids = prompt_ids
 
-        input_text = prompt if prompt is not None else self.tokenizer.decode(
-            prompt_ids)
+        input_text = prompt if prompt is not None else tokenizer.decode(
+            input_ids)
         token_num = len(input_ids)
 
         # Note: EmbeddingRequest doesn't have max_tokens
@@ -245,7 +239,9 @@ class OpenAIServing:
         else:
             return input_ids, input_text
 
-    def _get_decoded_token(self, logprob: Logprob, token_id: int) -> str:
+    @staticmethod
+    def _get_decoded_token(logprob: Logprob, token_id: int,
+                           tokenizer: PreTrainedTokenizer) -> str:
         if logprob.decoded_token is not None:
             return logprob.decoded_token
-        return self.tokenizer.decode(token_id)
+        return tokenizer.decode(token_id)

vllm/entrypoints/openai/serving_tokenization.py

@@ -9,7 +9,8 @@ from vllm.entrypoints.openai.protocol import (DetokenizeRequest,
                                               DetokenizeResponse,
                                               TokenizeRequest,
                                               TokenizeResponse)
-from vllm.entrypoints.openai.serving_engine import OpenAIServing
+from vllm.entrypoints.openai.serving_engine import (LoRAModulePath,
+                                                    OpenAIServing)
 
 
 class OpenAIServingTokenization(OpenAIServing):
@@ -18,13 +19,15 @@ class OpenAIServingTokenization(OpenAIServing):
                  engine: AsyncLLMEngine,
                  model_config: ModelConfig,
                  served_model_names: List[str],
+                 lora_modules: Optional[List[LoRAModulePath]] = None,
                  chat_template: Optional[str] = None):
         super().__init__(engine=engine,
                          model_config=model_config,
                          served_model_names=served_model_names,
-                         lora_modules=None)
+                         lora_modules=lora_modules)
 
-        load_chat_template(self, chat_template)
+        # If this is None we use the tokenizer's default chat template
+        self.chat_template = load_chat_template(chat_template)
 
     async def create_tokenize(self,
                               request: TokenizeRequest) -> TokenizeResponse:
@@ -40,20 +43,25 @@ class OpenAIServingTokenization(OpenAIServing):
             return self.create_error_response(
                 "Only one of `prompt` or `messages` should be provided.")
 
+        _, lora_request = self._maybe_get_adapter(request)
+        tokenizer = await self.engine.get_tokenizer(lora_request)
         if request.messages:
             conversation: List[ConversationMessage] = []
 
             for message in request.messages:
-                conversation.extend(
-                    parse_chat_message_content(self, message).messages)
+                result = parse_chat_message_content(message, self.model_config,
+                                                    tokenizer)
+                conversation.extend(result.messages)
 
-            request.prompt = self.tokenizer.apply_chat_template(
+            request.prompt = tokenizer.apply_chat_template(
                 add_generation_prompt=request.add_generation_prompt,
                 conversation=conversation,
-                tokenize=False)
+                tokenize=False,
+                chat_template=self.chat_template)
 
-        (input_ids, input_text) = self._validate_prompt_and_tokenize(
+        (input_ids, input_text) = await self._validate_prompt_and_tokenize(
             request,
+            tokenizer,
             prompt=request.prompt,
             add_special_tokens=request.add_special_tokens)
 
@@ -67,7 +75,9 @@ class OpenAIServingTokenization(OpenAIServing):
         if error_check_ret is not None:
             return error_check_ret
 
-        (input_ids, input_text) = self._validate_prompt_and_tokenize(
-            request, prompt_ids=request.tokens)
+        _, lora_request = self._maybe_get_adapter(request)
+        tokenizer = await self.engine.get_tokenizer(lora_request)
+        (input_ids, input_text) = await self._validate_prompt_and_tokenize(
+            request, tokenizer, prompt_ids=request.tokens)
 
         return DetokenizeResponse(prompt=input_text)

vllm/transformers_utils/detokenizer.py

@@ -165,6 +165,12 @@ class Detokenizer:
         return len(new_decoded_token_text)
 
 
+def _replace_none_with_empty(tokens: List[Optional[str]]):
+    for i, token in enumerate(tokens):
+        if token is None:
+            tokens[i] = ""
+
+
 def _convert_tokens_to_string_with_added_encoders(
     tokenizer: Union[PreTrainedTokenizer, PreTrainedTokenizerFast],
     output_tokens: List[str],
@@ -223,6 +229,8 @@ def convert_prompt_ids_to_tokens(
     read_offset = len(new_tokens)
     prefix_offset = max(
         read_offset - INITIAL_INCREMENTAL_DETOKENIZATION_OFFSET, 0)
+    # This is required to guard against out-of-vocab prompt token ids
+    _replace_none_with_empty(new_tokens)
     return new_tokens, prefix_offset, read_offset
 
 

vllm/transformers_utils/tokenizer.py

@@ -88,6 +88,9 @@ def get_tokenizer(
                 "Cannot use the fast tokenizer in slow tokenizer mode.")
         kwargs["use_fast"] = False
 
+    if "truncation_side" not in kwargs:
+        kwargs["truncation_side"] = "left"
+
     try:
         tokenizer = AutoTokenizer.from_pretrained(
             tokenizer_name,