[Core] Consolidate prompt arguments to LLM engines (#4328)

Co-authored-by: Roger Wang <ywang@roblox.com>

tests/entrypoints/test_openai_server.py

@@ -71,7 +71,7 @@ TEST_CHOICE = [
     "Swift", "Kotlin"
 ]
 
-pytestmark = pytest.mark.asyncio
+pytestmark = pytest.mark.openai
 
 
 @pytest.fixture(scope="session")
@@ -91,6 +91,8 @@ def server(zephyr_lora_files):
         "--max-model-len",
         "8192",
         "--enforce-eager",
+        "--gpu-memory-utilization",
+        "0.75",
         # lora config below
         "--enable-lora",
         "--lora-modules",
@@ -118,9 +120,11 @@ def embedding_server(zephyr_lora_files):
         # use half precision for speed and memory savings in CI environment
         "--dtype",
         "bfloat16",
+        "--enforce-eager",
+        "--gpu-memory-utilization",
+        "0.75",
         "--max-model-len",
         "8192",
-        "--enforce-eager",
     ])
     ray.get(server_runner.ready.remote())
     yield server_runner
@@ -136,6 +140,7 @@ def client():
     yield client
 
 
+@pytest.mark.asyncio
 async def test_check_models(server, client: openai.AsyncOpenAI):
     models = await client.models.list()
     models = models.data
@@ -147,6 +152,7 @@ async def test_check_models(server, client: openai.AsyncOpenAI):
     assert lora_models[1].id == "zephyr-lora2"
 
 
+@pytest.mark.asyncio
 @pytest.mark.parametrize(
     # first test base model, then test loras
     "model_name",
@@ -178,6 +184,7 @@ async def test_single_completion(server, client: openai.AsyncOpenAI,
         completion.choices[0].text) >= 5
 
 
+@pytest.mark.asyncio
 @pytest.mark.parametrize(
     # first test base model, then test loras
     "model_name",
@@ -199,6 +206,7 @@ async def test_zero_logprobs(server, client: openai.AsyncOpenAI,
     assert choice.logprobs.top_logprobs is None
 
 
+@pytest.mark.asyncio
 @pytest.mark.parametrize(
     # just test 1 lora hereafter
     "model_name",
@@ -243,6 +251,7 @@ async def test_single_chat_session(server, client: openai.AsyncOpenAI,
     assert message.content is not None and len(message.content) >= 0
 
 
+@pytest.mark.asyncio
 @pytest.mark.parametrize("model_name", [MODEL_NAME])
 async def test_too_many_logprobs(server, client: openai.AsyncOpenAI,
                                  model_name: str):
@@ -298,6 +307,7 @@ async def test_too_many_logprobs(server, client: openai.AsyncOpenAI,
     assert message.content is not None and len(message.content) >= 0
 
 
+@pytest.mark.asyncio
 @pytest.mark.parametrize(
     # just test 1 lora hereafter
     "model_name",
@@ -335,6 +345,7 @@ async def test_completion_streaming(server, client: openai.AsyncOpenAI,
     assert "".join(chunks) == single_output
 
 
+@pytest.mark.asyncio
 @pytest.mark.parametrize(
     # just test 1 lora hereafter
     "model_name",
@@ -385,6 +396,7 @@ async def test_chat_streaming(server, client: openai.AsyncOpenAI,
     assert "".join(chunks) == output
 
 
+@pytest.mark.asyncio
 @pytest.mark.parametrize(
     # just test 1 lora hereafter
     "model_name",
@@ -438,6 +450,7 @@ async def test_batch_completions(server, client: openai.AsyncOpenAI,
     assert texts[0] == texts[1]
 
 
+@pytest.mark.asyncio
 async def test_logits_bias(server, client: openai.AsyncOpenAI):
     prompt = "Hello, my name is"
     max_tokens = 5
@@ -485,6 +498,7 @@ async def test_logits_bias(server, client: openai.AsyncOpenAI):
     assert first_response != completion.choices[0].text
 
 
+@pytest.mark.asyncio
 @pytest.mark.parametrize("guided_decoding_backend",
                          ["outlines", "lm-format-enforcer"])
 async def test_guided_json_completion(server, client: openai.AsyncOpenAI,
@@ -507,6 +521,7 @@ async def test_guided_json_completion(server, client: openai.AsyncOpenAI,
         jsonschema.validate(instance=output_json, schema=TEST_SCHEMA)
 
 
+@pytest.mark.asyncio
 @pytest.mark.parametrize("guided_decoding_backend",
                          ["outlines", "lm-format-enforcer"])
 async def test_guided_json_chat(server, client: openai.AsyncOpenAI,
@@ -553,6 +568,7 @@ async def test_guided_json_chat(server, client: openai.AsyncOpenAI,
     assert json1["age"] != json2["age"]
 
 
+@pytest.mark.asyncio
 @pytest.mark.parametrize("guided_decoding_backend",
                          ["outlines", "lm-format-enforcer"])
 async def test_guided_regex_completion(server, client: openai.AsyncOpenAI,
@@ -573,6 +589,7 @@ async def test_guided_regex_completion(server, client: openai.AsyncOpenAI,
         assert re.fullmatch(TEST_REGEX, completion.choices[i].text) is not None
 
 
+@pytest.mark.asyncio
 @pytest.mark.parametrize("guided_decoding_backend",
                          ["outlines", "lm-format-enforcer"])
 async def test_guided_regex_chat(server, client: openai.AsyncOpenAI,
@@ -610,6 +627,7 @@ async def test_guided_regex_chat(server, client: openai.AsyncOpenAI,
     assert ip1 != ip2
 
 
+@pytest.mark.asyncio
 @pytest.mark.parametrize("guided_decoding_backend",
                          ["outlines", "lm-format-enforcer"])
 async def test_guided_choice_completion(server, client: openai.AsyncOpenAI,
@@ -629,6 +647,7 @@ async def test_guided_choice_completion(server, client: openai.AsyncOpenAI,
         assert completion.choices[i].text in TEST_CHOICE
 
 
+@pytest.mark.asyncio
 @pytest.mark.parametrize("guided_decoding_backend",
                          ["outlines", "lm-format-enforcer"])
 async def test_guided_choice_chat(server, client: openai.AsyncOpenAI,
@@ -667,6 +686,7 @@ async def test_guided_choice_chat(server, client: openai.AsyncOpenAI,
     assert choice1 != choice2
 
 
+@pytest.mark.asyncio
 @pytest.mark.parametrize("guided_decoding_backend",
                          ["outlines", "lm-format-enforcer"])
 async def test_guided_decoding_type_error(server, client: openai.AsyncOpenAI,
@@ -702,6 +722,7 @@ async def test_guided_decoding_type_error(server, client: openai.AsyncOpenAI,
             extra_body=dict(guided_regex=TEST_REGEX, guided_json=TEST_SCHEMA))
 
 
+@pytest.mark.asyncio
 @pytest.mark.parametrize("guided_decoding_backend",
                          ["outlines", "lm-format-enforcer"])
 async def test_guided_choice_chat_logprobs(server, client: openai.AsyncOpenAI,
@@ -732,6 +753,7 @@ async def test_guided_choice_chat_logprobs(server, client: openai.AsyncOpenAI,
         for token, logprob in token_dict.items())
 
 
+@pytest.mark.asyncio
 async def test_response_format_json_object(server, client: openai.AsyncOpenAI):
     for _ in range(2):
         resp = await client.chat.completions.create(
@@ -749,6 +771,7 @@ async def test_response_format_json_object(server, client: openai.AsyncOpenAI):
         assert loaded == {"result": 2}, loaded
 
 
+@pytest.mark.asyncio
 async def test_extra_fields(server, client: openai.AsyncOpenAI):
     with pytest.raises(BadRequestError) as exc_info:
         await client.chat.completions.create(
@@ -764,6 +787,7 @@ async def test_extra_fields(server, client: openai.AsyncOpenAI):
     assert "extra_forbidden" in exc_info.value.message
 
 
+@pytest.mark.asyncio
 async def test_complex_message_content(server, client: openai.AsyncOpenAI):
     resp = await client.chat.completions.create(
         model=MODEL_NAME,
@@ -783,6 +807,7 @@ async def test_complex_message_content(server, client: openai.AsyncOpenAI):
     assert content == "2"
 
 
+@pytest.mark.asyncio
 async def test_custom_role(server, client: openai.AsyncOpenAI):
     # Not sure how the model handles custom roles so we just check that
     # both string and complex message content are handled in the same way
@@ -813,6 +838,7 @@ async def test_custom_role(server, client: openai.AsyncOpenAI):
     assert content1 == content2
 
 
+@pytest.mark.asyncio
 async def test_guided_grammar(server, client: openai.AsyncOpenAI):
     simple_sql_grammar = """
 start: select_statement
@@ -847,6 +873,7 @@ number: "1" | "2"
     assert content.strip() == ground_truth
 
 
+@pytest.mark.asyncio
 @pytest.mark.parametrize(
     # first test base model, then test loras
     "model_name",
@@ -878,6 +905,7 @@ async def test_echo_logprob_completion(server, client: openai.AsyncOpenAI,
         assert len(logprobs.tokens) > 5
 
 
+@pytest.mark.asyncio
 async def test_long_seed(server, client: openai.AsyncOpenAI):
     for seed in [
             torch.iinfo(torch.long).min - 1,
@@ -897,6 +925,7 @@ async def test_long_seed(server, client: openai.AsyncOpenAI):
                 or "less_than_equal" in exc_info.value.message)
 
 
+@pytest.mark.asyncio
 @pytest.mark.parametrize(
     "model_name",
     [EMBEDDING_MODEL_NAME],
@@ -935,6 +964,7 @@ async def test_single_embedding(embedding_server, client: openai.AsyncOpenAI,
     assert embeddings.usage.total_tokens == 5
 
 
+@pytest.mark.asyncio
 @pytest.mark.parametrize(
     "model_name",
     [EMBEDDING_MODEL_NAME],

tests/entrypoints/test_server_oot_registration.py

-import multiprocessing
 import sys
 import time
 
+import pytest
 import torch
 from openai import OpenAI, OpenAIError
 
@@ -10,6 +10,8 @@ from vllm.model_executor.models.opt import OPTForCausalLM
 from vllm.model_executor.sampling_metadata import SamplingMetadata
 from vllm.utils import get_open_port
 
+pytestmark = pytest.mark.openai
+
 
 class MyOPTForCausalLM(OPTForCausalLM):
 
@@ -26,15 +28,16 @@ def server_function(port):
     # register our dummy model
     ModelRegistry.register_model("OPTForCausalLM", MyOPTForCausalLM)
     sys.argv = ["placeholder.py"] + \
-        ("--model facebook/opt-125m --dtype"
-        f" float32 --api-key token-abc123 --port {port}").split()
+        ("--model facebook/opt-125m --gpu-memory-utilization 0.10 "
+        f"--dtype float32 --api-key token-abc123 --port {port}").split()
     import runpy
     runpy.run_module('vllm.entrypoints.openai.api_server', run_name='__main__')
 
 
 def test_oot_registration_for_api_server():
     port = get_open_port()
-    server = multiprocessing.Process(target=server_function, args=(port, ))
+    ctx = torch.multiprocessing.get_context()
+    server = ctx.Process(target=server_function, args=(port, ))
     server.start()
     client = OpenAI(
         base_url=f"http://localhost:{port}/v1",

tests/lora/test_long_context.py

@@ -86,20 +86,18 @@ def generate(
 
 
 def batched_generate(
-    llm,
+    llm: vllm.LLM,
     inputs: List[Tuple[str, SamplingParams, Optional[LoRARequest]]],
 ):
     for input in inputs:
         prompt, sampling_param, lora_req = input
-        requests_data = llm._validate_and_prepare_requests(
+        # Add requests to the engine and run the engine
+        llm._validate_and_add_requests(
             prompt,
             sampling_param,
             lora_request=lora_req,
         )
 
-        # Add requests to the engine and run the engine
-        for request_data in requests_data:
-            llm._add_request(**request_data)
     outputs = llm._run_engine(use_tqdm=True)
     return [outputs[i].outputs[0].text.strip() for i in range(len(outputs))]
 

tests/samplers/test_logits_processor.py

@@ -35,28 +35,25 @@ def test_logits_processor_force_generate(
 
     # test logits_processors when prompt_logprobs is not None
     vllm_model.model._add_request(
-        prompt=example_prompts[0],
+        example_prompts[0],
         params=params_with_logprobs,
-        prompt_token_ids=None,
     )
 
     # test prompt_logprobs is not None
     vllm_model.model._add_request(
-        prompt=example_prompts[1],
+        example_prompts[1],
         params=SamplingParams(
             prompt_logprobs=3,
             max_tokens=max_tokens,
         ),
-        prompt_token_ids=None,
     )
 
     # test grouped requests
     vllm_model.model._add_request(
-        prompt=example_prompts[2],
+        example_prompts[2],
         params=SamplingParams(max_tokens=max_tokens),
-        prompt_token_ids=None,
     )
 
-    outputs = vllm_model.model._run_engine(False)
+    outputs = vllm_model.model._run_engine(use_tqdm=False)
 
     assert outputs[0].outputs[0].text == enforced_answers * repeat_times

tests/samplers/test_seeded_generate.py

@@ -57,11 +57,7 @@ def test_random_sample_with_seed(
                 sampling_params_seed_1,
                 sampling_params_seed_2,
         ):
-            llm._add_request(
-                prompt=prompt,
-                prompt_token_ids=None,
-                params=params,
-            )
+            llm._add_request(prompt, params=params)
 
     results = llm._run_engine(use_tqdm=False)
     all_outputs = [[out.token_ids for out in output.outputs]

tests/test_cache_block_hashing.py

@@ -70,8 +70,15 @@ def test_auto_prefix_caching(model: str, block_size: int, max_num_seqs: int,
             for prompt in prompts:
                 hashes[-1].append([])
                 prompt_token_ids = tokenizer.encode(prompt)
-                seq = Sequence(seq_id, prompt, prompt_token_ids, block_size,
-                               tokenizer.tokenizer.eos_token_id, lora_request)
+                seq = Sequence(seq_id,
+                               inputs={
+                                   "prompt": prompt,
+                                   "prompt_token_ids": prompt_token_ids,
+                                   "multi_modal_data": None,
+                               },
+                               block_size=block_size,
+                               eos_token_id=tokenizer.tokenizer.eos_token_id,
+                               lora_request=lora_request)
 
                 num_blocks = len(prompt_token_ids) // block_size
                 for idx in range(num_blocks):

tests/test_inputs.py

+from typing import List
+
+import pytest
+
+from vllm.inputs import parse_and_batch_prompt
+
+STRING_INPUTS = [
+    '',
+    'foo',
+    'foo bar',
+    'foo baz bar',
+    'foo bar qux baz',
+]
+
+TOKEN_INPUTS = [
+    [-1],
+    [1],
+    [1, 2],
+    [1, 3, 4],
+    [1, 2, 4, 3],
+]
+
+INPUTS_SLICES = [
+    slice(None, None, -1),
+    slice(None, None, 2),
+    slice(None, None, -2),
+]
+
+
+def test_parse_single_batch_empty():
+    with pytest.raises(ValueError, match="at least one prompt"):
+        parse_and_batch_prompt([])
+
+    with pytest.raises(ValueError, match="at least one prompt"):
+        parse_and_batch_prompt([[]])
+
+
+@pytest.mark.parametrize('string_input', STRING_INPUTS)
+def test_parse_single_batch_string_consistent(string_input: str):
+    assert parse_and_batch_prompt(string_input) \
+        == parse_and_batch_prompt([string_input])
+
+
+@pytest.mark.parametrize('token_input', TOKEN_INPUTS)
+def test_parse_single_batch_token_consistent(token_input: List[int]):
+    assert parse_and_batch_prompt(token_input) \
+        == parse_and_batch_prompt([token_input])
+
+
+@pytest.mark.parametrize('inputs_slice', INPUTS_SLICES)
+def test_parse_single_batch_string_slice(inputs_slice: slice):
+    assert parse_and_batch_prompt(STRING_INPUTS)[inputs_slice] \
+        == parse_and_batch_prompt(STRING_INPUTS[inputs_slice])

tests/test_utils.py

+import pytest
+
+from vllm.utils import deprecate_kwargs
+
+from .utils import error_on_warning
+
+
+def test_deprecate_kwargs_always():
+
+    @deprecate_kwargs("old_arg", is_deprecated=True)
+    def dummy(*, old_arg: object = None, new_arg: object = None):
+        pass
+
+    with pytest.warns(DeprecationWarning, match="'old_arg'"):
+        dummy(old_arg=1)
+
+    with error_on_warning():
+        dummy(new_arg=1)
+
+
+def test_deprecate_kwargs_never():
+
+    @deprecate_kwargs("old_arg", is_deprecated=False)
+    def dummy(*, old_arg: object = None, new_arg: object = None):
+        pass
+
+    with error_on_warning():
+        dummy(old_arg=1)
+
+    with error_on_warning():
+        dummy(new_arg=1)
+
+
+def test_deprecate_kwargs_dynamic():
+    is_deprecated = True
+
+    @deprecate_kwargs("old_arg", is_deprecated=lambda: is_deprecated)
+    def dummy(*, old_arg: object = None, new_arg: object = None):
+        pass
+
+    with pytest.warns(DeprecationWarning, match="'old_arg'"):
+        dummy(old_arg=1)
+
+    with error_on_warning():
+        dummy(new_arg=1)
+
+    is_deprecated = False
+
+    with error_on_warning():
+        dummy(old_arg=1)
+
+    with error_on_warning():
+        dummy(new_arg=1)
+
+
+def test_deprecate_kwargs_additional_message():
+
+    @deprecate_kwargs("old_arg", is_deprecated=True, additional_message="abcd")
+    def dummy(*, old_arg: object = None, new_arg: object = None):
+        pass
+
+    with pytest.warns(DeprecationWarning, match="abcd"):
+        dummy(old_arg=1)

tests/tokenization/test_detokenize.py

@@ -123,8 +123,11 @@ def create_sequence(prompt_token_ids=None):
     prompt_token_ids = prompt_token_ids or [1]
     return Sequence(
         seq_id=0,
-        prompt="<s>",
-        prompt_token_ids=prompt_token_ids,
+        inputs={
+            "prompt": "<s>",
+            "prompt_token_ids": prompt_token_ids,
+            "multi_modal_data": None,
+        },
         block_size=16,
     )
 

tests/utils.py

@@ -2,6 +2,8 @@ import os
 import subprocess
 import sys
 import time
+import warnings
+from contextlib import contextmanager
 
 import ray
 import requests
@@ -87,3 +89,15 @@ def multi_process_tensor_parallel(
     ray.get(refs)
 
     ray.shutdown()
+
+
+@contextmanager
+def error_on_warning():
+    """
+    Within the scope of this context manager, tests will fail if any warning
+    is emitted.
+    """
+    with warnings.catch_warnings():
+        warnings.simplefilter("error")
+
+        yield

vllm/__init__.py

@@ -5,6 +5,7 @@ from vllm.engine.async_llm_engine import AsyncLLMEngine
 from vllm.engine.llm_engine import LLMEngine
 from vllm.entrypoints.llm import LLM
 from vllm.executor.ray_utils import initialize_ray_cluster
+from vllm.inputs import PromptStrictInputs, TextPrompt, TokensPrompt
 from vllm.model_executor.models import ModelRegistry
 from vllm.outputs import (CompletionOutput, EmbeddingOutput,
                           EmbeddingRequestOutput, RequestOutput)
@@ -16,6 +17,9 @@ __version__ = "0.4.2"
 __all__ = [
     "LLM",
     "ModelRegistry",
+    "PromptStrictInputs",
+    "TextPrompt",
+    "TokensPrompt",
     "SamplingParams",
     "RequestOutput",
     "CompletionOutput",

vllm/engine/async_llm_engine.py

@@ -12,12 +12,13 @@ from vllm.core.scheduler import SchedulerOutputs
 from vllm.engine.arg_utils import AsyncEngineArgs
 from vllm.engine.llm_engine import LLMEngine
 from vllm.executor.ray_utils import initialize_ray_cluster, ray
+from vllm.inputs import LLMInputs, PromptInputs
 from vllm.logger import init_logger
 from vllm.lora.request import LoRARequest
 from vllm.outputs import EmbeddingRequestOutput, RequestOutput
 from vllm.pooling_params import PoolingParams
 from vllm.sampling_params import SamplingParams
-from vllm.sequence import ExecuteModelRequest, MultiModalData, SamplerOutput
+from vllm.sequence import ExecuteModelRequest, SamplerOutput
 from vllm.usage.usage_lib import UsageContext
 
 logger = init_logger(__name__)
@@ -244,64 +245,69 @@ class _AsyncLLMEngine(LLMEngine):
 
         return request_outputs
 
-    async def encode_request_async(
+    async def process_model_inputs_async(
         self,
-        request_id: str,  # pylint: disable=unused-argument
-        prompt: Optional[str],
-        prompt_token_ids: Optional[List[int]] = None,
+        request_id: str,
+        inputs: PromptInputs,
         lora_request: Optional[LoRARequest] = None,
-    ):
-        if prompt_token_ids is None:
-            assert prompt is not None
-            prompt_token_ids = await self.tokenizer.encode_async(
+    ) -> LLMInputs:
+        if isinstance(inputs, str):
+            inputs = {"prompt": inputs}
+
+        if "prompt_token_ids" not in inputs:
+            tokenizer = self.get_tokenizer_group("prompts must be None if "
+                                                 "skip_tokenizer_init is True")
+
+            prompt_token_ids = await tokenizer.encode_async(
                 request_id=request_id,
-                prompt=prompt,
+                prompt=inputs["prompt"],
                 lora_request=lora_request)
-        return prompt_token_ids
+        else:
+            prompt_token_ids = inputs["prompt_token_ids"]
+
+        return LLMInputs(prompt_token_ids=prompt_token_ids,
+                         prompt=inputs.get("prompt"),
+                         multi_modal_data=inputs.get("multi_modal_data"))
 
     async def add_request_async(
         self,
         request_id: str,
-        prompt: Optional[str],
+        inputs: PromptInputs,
         params: Union[SamplingParams, PoolingParams],
-        prompt_token_ids: Optional[List[int]] = None,
         arrival_time: Optional[float] = None,
         lora_request: Optional[LoRARequest] = None,
-        multi_modal_data: Optional[MultiModalData] = None,
     ) -> None:
         if lora_request is not None and not self.lora_config:
             raise ValueError(f"Got lora_request {lora_request} but LoRA is "
                              "not enabled!")
         if arrival_time is None:
             arrival_time = time.time()
-        prompt_token_ids = await self.encode_request_async(
+
+        processed_inputs = await self.process_model_inputs_async(
+            request_id=request_id, inputs=inputs, lora_request=lora_request)
+
+        self._add_processed_request(
             request_id=request_id,
-            prompt=prompt,
-            prompt_token_ids=prompt_token_ids,
-            lora_request=lora_request)
-
-        return self.add_request(request_id,
-                                prompt=prompt,
-                                params=params,
-                                prompt_token_ids=prompt_token_ids,
-                                arrival_time=arrival_time,
-                                lora_request=lora_request,
-                                multi_modal_data=multi_modal_data)
+            processed_inputs=processed_inputs,
+            params=params,
+            arrival_time=arrival_time,
+            lora_request=lora_request,
+        )
 
     async def check_health_async(self) -> None:
         self.model_executor.check_health()
 
 
 class AsyncLLMEngine:
-    """An asynchronous wrapper for LLMEngine.
+    """An asynchronous wrapper for :class:`LLMEngine`.
 
-    This class is used to wrap the LLMEngine class to make it asynchronous. It
-    uses asyncio to create a background loop that keeps processing incoming
-    requests. The LLMEngine is kicked by the generate method when there
-    are requests in the waiting queue. The generate method yields the outputs
-    from the LLMEngine to the caller.
+    This class is used to wrap the :class:`LLMEngine` class to make it
+    asynchronous. It uses asyncio to create a background loop that keeps
+    processing incoming requests. The :class:`LLMEngine` is kicked by the
+    generate method when there are requests in the waiting queue. The generate
+    method yields the outputs from the :class:`LLMEngine` to the caller.
 
-    NOTE: For the comprehensive list of arguments, see `LLMEngine`.
+    NOTE: For the comprehensive list of arguments, see :class:`LLMEngine`.
 
     Args:
         worker_use_ray: Whether to use Ray for model workers. Required for
@@ -315,8 +321,8 @@ class AsyncLLMEngine:
             being printed in log.
         start_engine_loop: If True, the background task to run the engine
             will be automatically started in the generate call.
-        *args: Arguments for LLMEngine.
-        *kwargs: Arguments for LLMEngine.
+        *args: Arguments for :class:`LLMEngine`.
+        **kwargs: Arguments for :class:`LLMEngine`.
     """
 
     _engine_class: Type[_AsyncLLMEngine] = _AsyncLLMEngine
@@ -526,22 +532,26 @@ class AsyncLLMEngine:
     async def add_request(
         self,
         request_id: str,
-        prompt: Optional[str],
+        inputs: PromptInputs,
         params: Union[SamplingParams, PoolingParams],
-        prompt_token_ids: Optional[List[int]] = None,
         arrival_time: Optional[float] = None,
         lora_request: Optional[LoRARequest] = None,
-        multi_modal_data: Optional[MultiModalData] = None,
     ) -> AsyncStream:
         if self.log_requests:
-            shortened_prompt = prompt
-            shortened_token_ids = prompt_token_ids
-            if self.max_log_len is not None:
+            if isinstance(inputs, str):
+                shortened_prompt = inputs
+                shortened_token_ids = None
+            else:
+                shortened_prompt = inputs.get("prompt")
+                shortened_token_ids = inputs.get("prompt_token_ids")
+
+            max_log_len = self.max_log_len
+            if max_log_len is not None:
                 if shortened_prompt is not None:
-                    shortened_prompt = shortened_prompt[:self.max_log_len]
+                    shortened_prompt = shortened_prompt[:max_log_len]
                 if shortened_token_ids is not None:
-                    shortened_token_ids = shortened_token_ids[:self.
-                                                              max_log_len]
+                    shortened_token_ids = shortened_token_ids[:max_log_len]
+
             logger.info(
                 "Received request %s: prompt: %r, "
                 "params: %s, prompt_token_ids: %s, "
@@ -562,39 +572,33 @@ class AsyncLLMEngine:
             arrival_time = time.time()
 
         if self.engine_use_ray:
-            prompt_token_ids = await (
-                self.engine.encode_request_async.remote(  # type: ignore
+            processed_inputs = await self.engine.process_model_inputs_async \
+                .remote(  # type: ignore
                     request_id=request_id,
-                    prompt=prompt,
-                    prompt_token_ids=prompt_token_ids,
-                    lora_request=lora_request))
+                    inputs=inputs,
+                    lora_request=lora_request)
         else:
-            prompt_token_ids = await self.engine.encode_request_async(
+            processed_inputs = await self.engine.process_model_inputs_async(
                 request_id=request_id,
-                prompt=prompt,
-                prompt_token_ids=prompt_token_ids,
+                inputs=inputs,
                 lora_request=lora_request)
 
         stream = self._request_tracker.add_request(
             request_id,
-            prompt=prompt,
+            inputs=processed_inputs,
             params=params,
-            prompt_token_ids=prompt_token_ids,
             arrival_time=arrival_time,
             lora_request=lora_request,
-            multi_modal_data=multi_modal_data,
         )
 
         return stream
 
     async def generate(
         self,
-        prompt: Optional[str],
+        inputs: PromptInputs,
         sampling_params: SamplingParams,
         request_id: str,
-        prompt_token_ids: Optional[List[int]] = None,
         lora_request: Optional[LoRARequest] = None,
-        multi_modal_data: Optional[MultiModalData] = None
     ) -> AsyncIterator[RequestOutput]:
         """Generate outputs for a request.
 
@@ -603,14 +607,12 @@ class AsyncLLMEngine:
         from the LLMEngine to the caller.
 
         Args:
-            prompt: The prompt string. Can be None if prompt_token_ids is
-                provided.
+            inputs: The inputs to the LLM. See
+                :class:`~vllm.inputs.PromptInputs`
+                for more details about the format of each input.
             sampling_params: The sampling parameters of the request.
             request_id: The unique id of the request.
-            prompt_token_ids: The token IDs of the prompt. If None, we
-                use the tokenizer to convert the prompts to token IDs.
             lora_request: LoRA request to use for generation, if any.
-            multi_modal_data: Multi modal data per request.
 
         Yields:
             The output `RequestOutput` objects from the LLMEngine
@@ -659,24 +661,20 @@ class AsyncLLMEngine:
             >>> # Process and return the final output
             >>> ...
         """
-        async for output in self.process_request(
+        async for output in self._process_request(
                 request_id,
-                prompt,
+                inputs,
                 sampling_params,
-                prompt_token_ids,
-                lora_request,
-                multi_modal_data,
+                lora_request=lora_request,
         ):
-            yield output
+            yield LLMEngine.validate_output(output, RequestOutput)
 
     async def encode(
         self,
-        prompt: Optional[str],
+        inputs: PromptInputs,
         pooling_params: PoolingParams,
         request_id: str,
-        prompt_token_ids: Optional[List[int]] = None,
         lora_request: Optional[LoRARequest] = None,
-        multi_modal_data: Optional[MultiModalData] = None
     ) -> AsyncIterator[EmbeddingRequestOutput]:
         """Generate outputs for a request from an embedding model.
 
@@ -685,14 +683,12 @@ class AsyncLLMEngine:
         from the LLMEngine to the caller.
 
         Args:
-            prompt: The prompt string. Can be None if prompt_token_ids is
-                provided.
+            inputs: The inputs to the LLM. See
+                :class:`~vllm.inputs.PromptInputs`
+                for more details about the format of each input.
             pooling_params: The pooling parameters of the request.
             request_id: The unique id of the request.
-            prompt_token_ids: The token IDs of the prompt. If None, we
-                use the tokenizer to convert the prompts to token IDs.
             lora_request: LoRA request to use for generation, if any.
-            multi_modal_data: Multi modal data per request.
 
         Yields:
             The output `EmbeddingRequestOutput` objects from the LLMEngine
@@ -739,24 +735,21 @@ class AsyncLLMEngine:
             >>> # Process and return the final output
             >>> ...
         """
-        async for output in self.process_request(
+        async for output in self._process_request(
                 request_id,
-                prompt,
+                inputs,
                 pooling_params,
-                prompt_token_ids,
-                lora_request,
-                multi_modal_data,
+                lora_request=lora_request,
         ):
-            yield output
+            yield LLMEngine.validate_output(output, EmbeddingRequestOutput)
 
-    async def process_request(
+    async def _process_request(
         self,
         request_id: str,
-        prompt: Optional[str],
+        inputs: PromptInputs,
         params: Union[SamplingParams, PoolingParams],
-        prompt_token_ids: Optional[List[int]] = None,
+        *,
         lora_request: Optional[LoRARequest] = None,
-        multi_modal_data: Optional[MultiModalData] = None,
     ) -> AsyncIterator[Union[RequestOutput, EmbeddingRequestOutput]]:
         """Common logic to process requests with SamplingParams or
         PoolingParams."""
@@ -764,12 +757,10 @@ class AsyncLLMEngine:
 
         stream = await self.add_request(
             request_id,
-            prompt,
+            inputs,
             params,
-            prompt_token_ids=prompt_token_ids,
             arrival_time=arrival_time,
             lora_request=lora_request,
-            multi_modal_data=multi_modal_data,
         )
 
         try:

vllm/engine/llm_engine.py

 import time
-from typing import Iterable, List, Optional, Type, Union
+from contextlib import contextmanager
+from typing import TYPE_CHECKING, ClassVar, Iterable, List, Optional
+from typing import Sequence as GenericSequence
+from typing import Type, TypeVar, Union
 
 from transformers import GenerationConfig, PreTrainedTokenizer
 
@@ -18,6 +21,7 @@ from vllm.engine.output_processor.stop_checker import StopChecker
 from vllm.engine.output_processor.util import create_output_by_sequence_group
 from vllm.executor.executor_base import ExecutorBase
 from vllm.executor.ray_utils import initialize_ray_cluster
+from vllm.inputs import LLMInputs, PromptInputs
 from vllm.logger import init_logger
 from vllm.lora.request import LoRARequest
 from vllm.outputs import (EmbeddingRequestOutput, RequestOutput,
@@ -25,8 +29,8 @@ from vllm.outputs import (EmbeddingRequestOutput, RequestOutput,
 from vllm.pooling_params import PoolingParams
 from vllm.sampling_params import SamplingParams
 from vllm.sequence import (EmbeddingSequenceGroupOutput, ExecuteModelRequest,
-                           MultiModalData, PoolerOutput, SamplerOutput,
-                           Sequence, SequenceGroup, SequenceGroupMetadata,
+                           PoolerOutput, SamplerOutput, Sequence,
+                           SequenceGroup, SequenceGroupMetadata,
                            SequenceStatus)
 from vllm.transformers_utils.detokenizer import Detokenizer
 from vllm.transformers_utils.tokenizer_group import (BaseTokenizerGroup,
@@ -50,6 +54,9 @@ def _load_generation_config_dict(model_config: ModelConfig):
         return {}
 
 
+_O = TypeVar("_O", RequestOutput, EmbeddingRequestOutput)
+
+
 class LLMEngine:
     """An LLM engine that receives requests and generates texts.
 
@@ -60,11 +67,11 @@ class LLMEngine:
     iteration-level scheduling and efficient memory management to maximize the
     serving throughput.
 
-    The `LLM` class wraps this class for offline batched inference and the
-    `AsyncLLMEngine` class wraps this class for online serving.
+    The :class:`~vllm.LLM` class wraps this class for offline batched inference
+    and the :class:`AsyncLLMEngine` class wraps this class for online serving.
 
-    NOTE: The config arguments are derived from the `EngineArgs` class. For the
-    comprehensive list of arguments, see `EngineArgs`.
+    NOTE: The config arguments are derived from the :class:`~vllm.EngineArgs`
+    class. For the comprehensive list of arguments, see :ref:`engine_args`.
 
     Args:
         model_config: The configuration related to the LLM model.
@@ -81,9 +88,60 @@ class LLMEngine:
         executor_class: The model executor class for managing distributed
             execution.
         log_stats: Whether to log statistics.
-        usage_context: Specified entry point, used for usage info collection
+        usage_context: Specified entry point, used for usage info collection.
     """
 
+    DO_VALIDATE_OUTPUT: ClassVar[bool] = False
+    """A flag to toggle whether to validate the type of request output."""
+
+    @classmethod
+    @contextmanager
+    def enable_output_validation(cls):
+        cls.DO_VALIDATE_OUTPUT = True
+
+        yield
+
+        cls.DO_VALIDATE_OUTPUT = False
+
+    @classmethod
+    def validate_output(
+        cls,
+        output: object,
+        output_type: Type[_O],
+    ) -> _O:
+        do_validate = cls.DO_VALIDATE_OUTPUT
+
+        if ((TYPE_CHECKING or do_validate)
+                and not isinstance(output, output_type)):
+            raise TypeError(f"Expected output of type {output_type}, "
+                            f"but found type {type(output)}")
+
+        return output
+
+    @classmethod
+    def validate_outputs(
+        cls,
+        outputs: GenericSequence[object],
+        output_type: Type[_O],
+    ) -> List[_O]:
+        do_validate = cls.DO_VALIDATE_OUTPUT
+
+        outputs_: List[_O]
+        if TYPE_CHECKING or do_validate:
+            outputs_ = []
+            for output in outputs:
+                if not isinstance(output, output_type):
+                    raise TypeError(f"Expected output of type {output_type}, "
+                                    f"but found type {type(output)}")
+
+                outputs_.append(output)
+        else:
+            outputs_ = outputs
+
+        return outputs_
+
+    tokenizer: Optional[BaseTokenizerGroup]
+
     def __init__(
         self,
         model_config: ModelConfig,
@@ -151,12 +209,11 @@ class LLMEngine:
         self.log_stats = log_stats
 
         if not self.model_config.skip_tokenizer_init:
-            self.tokenizer: BaseTokenizerGroup
-            self._init_tokenizer()
+            self.tokenizer = self._init_tokenizer()
             self.detokenizer = Detokenizer(self.tokenizer)
         else:
-            self.detokenizer = None
             self.tokenizer = None
+            self.detokenizer = None
 
         self.seq_counter = Counter()
         self.generation_config_fields = _load_generation_config_dict(
@@ -318,14 +375,26 @@ class LLMEngine:
         if model_executor := getattr(self, "model_executor", None):
             model_executor.shutdown()
 
+    MISSING_TOKENIZER_GROUP_MSG = ("Unable to get tokenizer because "
+                                   "skip_tokenizer_init is True")
+
+    def get_tokenizer_group(
+            self,
+            fail_msg: str = MISSING_TOKENIZER_GROUP_MSG) -> BaseTokenizerGroup:
+        if self.tokenizer is None:
+            raise ValueError(fail_msg)
+
+        return self.tokenizer
+
     def get_tokenizer(self) -> "PreTrainedTokenizer":
-        return self.tokenizer.get_lora_tokenizer(None)
+        return self.get_tokenizer_group().get_lora_tokenizer(None)
 
     def get_tokenizer_for_seq(self,
                               sequence: Sequence) -> "PreTrainedTokenizer":
-        return self.tokenizer.get_lora_tokenizer(sequence.lora_request)
+        return self.get_tokenizer_group().get_lora_tokenizer(
+            sequence.lora_request)
 
-    def _init_tokenizer(self, **tokenizer_init_kwargs):
+    def _init_tokenizer(self, **tokenizer_init_kwargs) -> BaseTokenizerGroup:
         init_kwargs = dict(
             tokenizer_id=self.model_config.tokenizer,
             enable_lora=bool(self.lora_config),
@@ -335,8 +404,9 @@ class LLMEngine:
             trust_remote_code=self.model_config.trust_remote_code,
             revision=self.model_config.tokenizer_revision)
         init_kwargs.update(tokenizer_init_kwargs)
-        self.tokenizer = get_tokenizer_group(
-            self.parallel_config.tokenizer_pool_config, **init_kwargs)
+
+        return get_tokenizer_group(self.parallel_config.tokenizer_pool_config,
+                                   **init_kwargs)
 
     def _verify_args(self) -> None:
         self.model_config.verify_with_parallel_config(self.parallel_config)
@@ -346,29 +416,85 @@ class LLMEngine:
             self.lora_config.verify_with_scheduler_config(
                 self.scheduler_config)
 
-    def encode_request(
+    def _get_eos_token_id(
+            self, lora_request: Optional[LoRARequest]) -> Optional[int]:
+        if self.tokenizer is None:
+            logger.warning("Using None for EOS token id because tokenizer "
+                           "is not initialized")
+            return None
+
+        return self.tokenizer.get_lora_tokenizer(lora_request).eos_token_id
+
+    def _add_processed_request(
         self,
-        request_id: str,  # pylint: disable=unused-argument
-        prompt: Optional[str],
-        prompt_token_ids: Optional[List[int]] = None,
+        request_id: str,
+        processed_inputs: LLMInputs,
+        params: Union[SamplingParams, PoolingParams],
+        arrival_time: float,
+        lora_request: Optional[LoRARequest],
+    ) -> None:
+        # Create the sequences.
+        block_size = self.cache_config.block_size
+        seq_id = next(self.seq_counter)
+        eos_token_id = self._get_eos_token_id(lora_request)
+
+        seq = Sequence(seq_id, processed_inputs, block_size, eos_token_id,
+                       lora_request)
+
+        # Create a SequenceGroup based on SamplingParams or PoolingParams
+        if isinstance(params, SamplingParams):
+            seq_group = self._create_sequence_group_with_sampling(
+                request_id,
+                seq,
+                params,
+                arrival_time=arrival_time,
+                lora_request=lora_request,
+            )
+        elif isinstance(params, PoolingParams):
+            seq_group = self._create_sequence_group_with_pooling(
+                request_id,
+                seq,
+                params,
+                arrival_time=arrival_time,
+                lora_request=lora_request,
+            )
+        else:
+            raise ValueError(
+                "Either SamplingParams or PoolingParams must be provided.")
+
+        # Add the sequence group to the scheduler.
+        self.scheduler.add_seq_group(seq_group)
+
+    def process_model_inputs(
+        self,
+        request_id: str,
+        inputs: PromptInputs,
         lora_request: Optional[LoRARequest] = None,
-    ):
-        if prompt_token_ids is None:
-            assert prompt is not None
-            prompt_token_ids = self.tokenizer.encode(request_id=request_id,
-                                                     prompt=prompt,
-                                                     lora_request=lora_request)
-        return prompt_token_ids
+    ) -> LLMInputs:
+        if isinstance(inputs, str):
+            inputs = {"prompt": inputs}
+
+        if "prompt_token_ids" not in inputs:
+            tokenizer = self.get_tokenizer_group("prompts must be None if "
+                                                 "skip_tokenizer_init is True")
+
+            prompt_token_ids = tokenizer.encode(request_id=request_id,
+                                                prompt=inputs["prompt"],
+                                                lora_request=lora_request)
+        else:
+            prompt_token_ids = inputs["prompt_token_ids"]
+
+        return LLMInputs(prompt_token_ids=prompt_token_ids,
+                         prompt=inputs.get("prompt"),
+                         multi_modal_data=inputs.get("multi_modal_data"))
 
     def add_request(
         self,
         request_id: str,
-        prompt: Optional[str],
+        inputs: PromptInputs,
         params: Union[SamplingParams, PoolingParams],
-        prompt_token_ids: Optional[List[int]] = None,
         arrival_time: Optional[float] = None,
         lora_request: Optional[LoRARequest] = None,
-        multi_modal_data: Optional[MultiModalData] = None,
     ) -> None:
         """Add a request to the engine's request pool.
 
@@ -378,15 +504,14 @@ class LLMEngine:
 
         Args:
             request_id: The unique ID of the request.
-            prompt: The prompt string. Can be None if prompt_token_ids is
-                provided.
-            params: Parameters for sampling or pooling. SamplingParams
-                for text generation. PoolingParams for pooling.
-            prompt_token_ids: The token IDs of the prompt. If None, we
-                use the tokenizer to convert the prompts to token IDs.
+            inputs: The inputs to the LLM. See
+                :class:`~vllm.inputs.PromptInputs`
+                for more details about the format of each input.
+            params: Parameters for sampling or pooling.
+                :class:`~vllm.SamplingParams` for text generation.
+                :class:`~vllm.PoolingParams` for pooling.
             arrival_time: The arrival time of the request. If None, we use
                 the current monotonic time.
-            multi_modal_data: Multi modal data per request.
 
         Details:
             - Set arrival_time to the current time if it is None.
@@ -417,59 +542,26 @@ class LLMEngine:
                              "not enabled!")
         if arrival_time is None:
             arrival_time = time.time()
-        prompt_token_ids = self.encode_request(
-            request_id=request_id,
-            prompt=prompt,
-            prompt_token_ids=prompt_token_ids,
-            lora_request=lora_request)
-
-        # Create the sequences.
-        block_size = self.cache_config.block_size
-        seq_id = next(self.seq_counter)
-        eos_token_id = None
-        if self.tokenizer:
-            eos_token_id = self.tokenizer.get_lora_tokenizer(
-                lora_request).eos_token_id
-        else:
-            logger.warning("Use None for EOS token id because tokenizer is "
-                           "not initialized")
-        seq = Sequence(seq_id, prompt, prompt_token_ids, block_size,
-                       eos_token_id, lora_request)
 
-        # Create a SequenceGroup based on SamplingParams or PoolingParams
-        if isinstance(params, SamplingParams):
-            seq_group = self._create_sequence_group_with_sampling(
-                request_id,
-                seq,
-                params,
-                arrival_time,
-                lora_request,
-                multi_modal_data,
-            )
-        elif isinstance(params, PoolingParams):
-            seq_group = self._create_sequence_group_with_pooling(
-                request_id,
-                seq,
-                params,
-                arrival_time,
-                lora_request,
-                multi_modal_data,
-            )
-        else:
-            raise ValueError(
-                "Either SamplingParams or PoolingParams must be provided.")
+        processed_inputs = self.process_model_inputs(request_id=request_id,
+                                                     inputs=inputs,
+                                                     lora_request=lora_request)
 
-        # Add the sequence group to the scheduler.
-        self.scheduler.add_seq_group(seq_group)
+        self._add_processed_request(
+            request_id=request_id,
+            processed_inputs=processed_inputs,
+            params=params,
+            arrival_time=arrival_time,
+            lora_request=lora_request,
+        )
 
     def _create_sequence_group_with_sampling(
         self,
         request_id: str,
         seq: Sequence,
         sampling_params: SamplingParams,
-        arrival_time: Optional[float] = None,
-        lora_request: Optional[LoRARequest] = None,
-        multi_modal_data: Optional[MultiModalData] = None,
+        arrival_time: float,
+        lora_request: Optional[LoRARequest],
     ) -> SequenceGroup:
         """Creates a SequenceGroup with SamplingParams."""
         max_logprobs = self.get_model_config().max_logprobs
@@ -495,8 +587,7 @@ class LLMEngine:
                                   seqs=[seq],
                                   arrival_time=arrival_time,
                                   sampling_params=sampling_params,
-                                  lora_request=lora_request,
-                                  multi_modal_data=multi_modal_data)
+                                  lora_request=lora_request)
 
         return seq_group
 
@@ -505,9 +596,8 @@ class LLMEngine:
         request_id: str,
         seq: Sequence,
         pooling_params: PoolingParams,
-        arrival_time: Optional[float] = None,
-        lora_request: Optional[LoRARequest] = None,
-        multi_modal_data: Optional[MultiModalData] = None,
+        arrival_time: float,
+        lora_request: Optional[LoRARequest],
     ) -> SequenceGroup:
         """Creates a SequenceGroup with PoolingParams."""
         # Defensive copy of PoolingParams, which are used by the pooler
@@ -517,7 +607,6 @@ class LLMEngine:
                                   seqs=[seq],
                                   arrival_time=arrival_time,
                                   lora_request=lora_request,
-                                  multi_modal_data=multi_modal_data,
                                   pooling_params=pooling_params)
         return seq_group
 
@@ -570,7 +659,7 @@ class LLMEngine:
 
     def _process_model_outputs(
         self,
-        output: List[Union[SamplerOutput, PoolerOutput]],
+        output: GenericSequence[Union[SamplerOutput, PoolerOutput]],
         scheduled_seq_groups: List[ScheduledSequenceGroup],
         ignored_seq_groups: List[SequenceGroup],
         seq_group_metadata_list: List[SequenceGroupMetadata],
@@ -585,7 +674,7 @@ class LLMEngine:
         # Organize outputs by [sequence group][step] instead of
         # [step][sequence group].
         output_by_sequence_group = create_output_by_sequence_group(
-            sampler_outputs=output, num_seq_groups=len(scheduled_seq_groups))
+            output, num_seq_groups=len(scheduled_seq_groups))
 
         # Update the scheduled sequence groups with the model outputs.
         for scheduled_seq_group, outputs, seq_group_meta in zip(

vllm/engine/output_processor/util.py

 from typing import List
+from typing import Sequence as GenericSequence
+from typing import Union
 
-from vllm.sequence import SamplerOutput, SequenceGroupOutput
+from vllm.sequence import PoolerOutput, SamplerOutput, SequenceGroupOutput
 
 
 def create_output_by_sequence_group(
-        sampler_outputs: List[SamplerOutput],
+        outputs: GenericSequence[Union[SamplerOutput, PoolerOutput]],
         num_seq_groups: int) -> List[List[SequenceGroupOutput]]:
     """Helper method which transforms a 2d list organized by
     [step][sequence group] into [sequence group][step].
     """
-    output_by_sequence_group: List[List[SamplerOutput]] = [
+    output_by_sequence_group: List[List[SequenceGroupOutput]] = [
         [] for _ in range(num_seq_groups)
     ]
-    for step in sampler_outputs:
+    for step in outputs:
         for i, sequence_group_output in enumerate(step):
             output_by_sequence_group[i].append(sequence_group_output)
 

vllm/entrypoints/llm.py

-from typing import List, Optional, Union
+from contextlib import contextmanager
+from typing import ClassVar, List, Optional, Sequence, Union, cast, overload
 
-import torch
 from tqdm import tqdm
 from transformers import PreTrainedTokenizer, PreTrainedTokenizerFast
 
 from vllm.engine.arg_utils import EngineArgs
 from vllm.engine.llm_engine import LLMEngine
+from vllm.inputs import (PromptInputs, PromptStrictInputs, TextPrompt,
+                         TextTokensPrompt, TokensPrompt,
+                         parse_and_batch_prompt)
 from vllm.logger import init_logger
 from vllm.lora.request import LoRARequest
 from vllm.outputs import EmbeddingRequestOutput, RequestOutput
@@ -13,7 +16,7 @@ from vllm.pooling_params import PoolingParams
 from vllm.sampling_params import SamplingParams
 from vllm.sequence import MultiModalData
 from vllm.usage.usage_lib import UsageContext
-from vllm.utils import Counter
+from vllm.utils import Counter, deprecate_kwargs
 
 logger = init_logger(__name__)
 
@@ -28,8 +31,10 @@ class LLM:
     mechanism and efficient memory management.
 
     NOTE: This class is intended to be used for offline inference. For online
-    serving, use the `AsyncLLMEngine` class instead.
-    NOTE: For the comprehensive list of arguments, see `EngineArgs`.
+    serving, use the :class:`~vllm.AsyncLLMEngine` class instead.
+
+    NOTE: For the comprehensive list of arguments, see
+    :class:`~vllm.EngineArgs`.
 
     Args:
         model: The name or path of a HuggingFace Transformers model.
@@ -81,6 +86,18 @@ class LLM:
         disable_custom_all_reduce: See ParallelConfig
     """
 
+    DEPRECATE_LEGACY: ClassVar[bool] = False
+    """A flag to toggle whether to deprecate the legacy generate/encode API."""
+
+    @classmethod
+    @contextmanager
+    def deprecate_legacy_api(cls):
+        cls.DEPRECATE_LEGACY = True
+
+        yield
+
+        cls.DEPRECATE_LEGACY = False
+
     def __init__(
         self,
         model: str,
@@ -138,15 +155,101 @@ class LLM:
     ) -> None:
         self.llm_engine.tokenizer.tokenizer = tokenizer
 
+    @overload  # LEGACY: single (prompt + optional token ids)
+    def generate(
+        self,
+        prompts: str,
+        sampling_params: Optional[Union[SamplingParams,
+                                        List[SamplingParams]]] = None,
+        prompt_token_ids: Optional[List[int]] = None,
+        use_tqdm: bool = True,
+        lora_request: Optional[LoRARequest] = None,
+        multi_modal_data: Optional[MultiModalData] = None,
+    ) -> List[RequestOutput]:
+        ...
+
+    @overload  # LEGACY: multi (prompt + optional token ids)
     def generate(
         self,
-        prompts: Optional[Union[str, List[str]]] = None,
+        prompts: List[str],
         sampling_params: Optional[Union[SamplingParams,
                                         List[SamplingParams]]] = None,
         prompt_token_ids: Optional[List[List[int]]] = None,
         use_tqdm: bool = True,
         lora_request: Optional[LoRARequest] = None,
         multi_modal_data: Optional[MultiModalData] = None,
+    ) -> List[RequestOutput]:
+        ...
+
+    @overload  # LEGACY: single (token ids + optional prompt)
+    def generate(
+        self,
+        prompts: Optional[str] = None,
+        sampling_params: Optional[Union[SamplingParams,
+                                        List[SamplingParams]]] = None,
+        *,
+        prompt_token_ids: List[int],
+        use_tqdm: bool = True,
+        lora_request: Optional[LoRARequest] = None,
+        multi_modal_data: Optional[MultiModalData] = None,
+    ) -> List[RequestOutput]:
+        ...
+
+    @overload  # LEGACY: multi (token ids + optional prompt)
+    def generate(
+        self,
+        prompts: Optional[List[str]] = None,
+        sampling_params: Optional[Union[SamplingParams,
+                                        List[SamplingParams]]] = None,
+        *,
+        prompt_token_ids: List[List[int]],
+        use_tqdm: bool = True,
+        lora_request: Optional[LoRARequest] = None,
+        multi_modal_data: Optional[MultiModalData] = None,
+    ) -> List[RequestOutput]:
+        ...
+
+    @overload  # LEGACY: single or multi token ids [pos-only]
+    def generate(
+        self,
+        prompts: None,
+        sampling_params: None,
+        prompt_token_ids: Union[List[int], List[List[int]]],
+        use_tqdm: bool = True,
+        lora_request: Optional[LoRARequest] = None,
+        multi_modal_data: Optional[MultiModalData] = None,
+    ) -> List[RequestOutput]:
+        ...
+
+    @overload
+    def generate(
+        self,
+        inputs: Union[PromptStrictInputs, Sequence[PromptStrictInputs]],
+        /,  # We may enable `inputs` keyword after removing the old API
+        *,
+        sampling_params: Optional[Union[SamplingParams,
+                                        Sequence[SamplingParams]]] = None,
+        use_tqdm: bool = True,
+        lora_request: Optional[LoRARequest] = None,
+    ) -> List[RequestOutput]:
+        ...
+
+    @deprecate_kwargs("prompts",
+                      "prompt_token_ids",
+                      "multi_modal_data",
+                      is_deprecated=lambda: LLM.DEPRECATE_LEGACY,
+                      additional_message="Please use the 'inputs' parameter "
+                      "instead.")
+    def generate(
+        self,
+        prompts: Union[Union[PromptStrictInputs, Sequence[PromptStrictInputs]],
+                       Optional[Union[str, List[str]]]] = None,
+        sampling_params: Optional[Union[SamplingParams,
+                                        Sequence[SamplingParams]]] = None,
+        prompt_token_ids: Optional[Union[List[int], List[List[int]]]] = None,
+        use_tqdm: bool = True,
+        lora_request: Optional[LoRARequest] = None,
+        multi_modal_data: Optional[MultiModalData] = None,
     ) -> List[RequestOutput]:
         """Generates the completions for the input prompts.
 
@@ -155,49 +258,138 @@ class LLM:
         into a single list and pass it to this method.
 
         Args:
-            prompts: A list of prompts to generate completions for.
+            inputs: A list of inputs to generate completions for.
             sampling_params: The sampling parameters for text generation. If
                 None, we use the default sampling parameters. 
                 When it is a single value, it is applied to every prompt. 
                 When it is a list, the list must have the same length as the 
                 prompts and it is paired one by one with the prompt.
-            prompt_token_ids: A list of token IDs for the prompts. If None, we
-                use the tokenizer to convert the prompts to token IDs.
             use_tqdm: Whether to use tqdm to display the progress bar.
             lora_request: LoRA request to use for generation, if any.
-            multi_modal_data: Multi modal data.
 
         Returns:
             A list of `RequestOutput` objects containing the
             generated completions in the same order as the input prompts.
         """
+        if prompt_token_ids is not None or multi_modal_data is not None:
+            inputs = self._convert_v1_inputs(
+                prompts=cast(Optional[Union[str, List[str]]], prompts),
+                prompt_token_ids=prompt_token_ids,
+                multi_modal_data=multi_modal_data,
+            )
+        else:
+            inputs = cast(
+                Union[PromptStrictInputs, Sequence[PromptStrictInputs]],
+                prompts)
+
         if sampling_params is None:
             # Use default sampling params.
             sampling_params = SamplingParams()
 
-        requests_data = self._validate_and_prepare_requests(
-            prompts,
-            sampling_params,
-            prompt_token_ids,
-            lora_request,
-            multi_modal_data,
+        self._validate_and_add_requests(
+            inputs=inputs,
+            params=sampling_params,
+            lora_request=lora_request,
         )
 
-        # Add requests to the engine and run the engine
-        for request_data in requests_data:
-            self._add_request(**request_data)
+        outputs = self._run_engine(use_tqdm=use_tqdm)
+        return LLMEngine.validate_outputs(outputs, RequestOutput)
 
-        return self._run_engine(use_tqdm)
+    @overload  # LEGACY: single (prompt + optional token ids)
+    def encode(
+        self,
+        prompts: str,
+        pooling_params: Optional[Union[PoolingParams,
+                                       Sequence[PoolingParams]]] = None,
+        prompt_token_ids: Optional[List[int]] = None,
+        use_tqdm: bool = True,
+        lora_request: Optional[LoRARequest] = None,
+        multi_modal_data: Optional[MultiModalData] = None,
+    ) -> List[EmbeddingRequestOutput]:
+        ...
 
+    @overload  # LEGACY: multi (prompt + optional token ids)
     def encode(
         self,
-        prompts: Optional[Union[str, List[str]]] = None,
+        prompts: List[str],
         pooling_params: Optional[Union[PoolingParams,
-                                       List[PoolingParams]]] = None,
+                                       Sequence[PoolingParams]]] = None,
         prompt_token_ids: Optional[List[List[int]]] = None,
         use_tqdm: bool = True,
         lora_request: Optional[LoRARequest] = None,
         multi_modal_data: Optional[MultiModalData] = None,
+    ) -> List[EmbeddingRequestOutput]:
+        ...
+
+    @overload  # LEGACY: single (token ids + optional prompt)
+    def encode(
+        self,
+        prompts: Optional[str] = None,
+        pooling_params: Optional[Union[PoolingParams,
+                                       Sequence[PoolingParams]]] = None,
+        *,
+        prompt_token_ids: List[int],
+        use_tqdm: bool = True,
+        lora_request: Optional[LoRARequest] = None,
+        multi_modal_data: Optional[MultiModalData] = None,
+    ) -> List[EmbeddingRequestOutput]:
+        ...
+
+    @overload  # LEGACY: multi (token ids + optional prompt)
+    def encode(
+        self,
+        prompts: Optional[List[str]] = None,
+        pooling_params: Optional[Union[PoolingParams,
+                                       Sequence[PoolingParams]]] = None,
+        *,
+        prompt_token_ids: List[List[int]],
+        use_tqdm: bool = True,
+        lora_request: Optional[LoRARequest] = None,
+        multi_modal_data: Optional[MultiModalData] = None,
+    ) -> List[EmbeddingRequestOutput]:
+        ...
+
+    @overload  # LEGACY: single or multi token ids [pos-only]
+    def encode(
+        self,
+        prompts: None,
+        pooling_params: None,
+        prompt_token_ids: Union[List[int], List[List[int]]],
+        use_tqdm: bool = True,
+        lora_request: Optional[LoRARequest] = None,
+        multi_modal_data: Optional[MultiModalData] = None,
+    ) -> List[EmbeddingRequestOutput]:
+        ...
+
+    @overload
+    def encode(
+        self,
+        inputs: Union[PromptStrictInputs, Sequence[PromptStrictInputs]],
+        /,  # We may enable `inputs` keyword after removing the old API
+        *,
+        pooling_params: Optional[Union[PoolingParams,
+                                       Sequence[PoolingParams]]] = None,
+        use_tqdm: bool = True,
+        lora_request: Optional[LoRARequest] = None,
+    ) -> List[EmbeddingRequestOutput]:
+        ...
+
+    @deprecate_kwargs("prompts",
+                      "prompt_token_ids",
+                      "multi_modal_data",
+                      is_deprecated=lambda: LLM.DEPRECATE_LEGACY,
+                      additional_message="Please use the 'inputs' parameter "
+                      "instead.")
+    def encode(
+        self,
+        prompts: Union[Union[PromptStrictInputs, Sequence[PromptStrictInputs]],
+                       Optional[Union[str, List[str]]]] = None,
+        pooling_params: Optional[Union[PoolingParams,
+                                       Sequence[PoolingParams]]] = None,
+        prompt_token_ids: Optional[Union[List[int], List[List[int]]]] = None,
+        use_tqdm: bool = True,
+        lora_request: Optional[LoRARequest] = None,
+        multi_modal_data: Optional[MultiModalData] = None,
     ) -> List[EmbeddingRequestOutput]:
         """Generates the completions for the input prompts.
 
@@ -206,124 +398,133 @@ class LLM:
         into a single list and pass it to this method.
 
         Args:
-            prompts: A list of prompts to generate completions for.
+            inputs: The inputs to the LLM. You may pass a sequence of inputs for
+                batch inference. See :class:`~vllm.inputs.PromptStrictInputs`
+                for more details about the format of each input.
             pooling_params: The pooling parameters for pooling. If None, we
                 use the default pooling parameters.
-            prompt_token_ids: A list of token IDs for the prompts. If None, we
-                use the tokenizer to convert the prompts to token IDs.
             use_tqdm: Whether to use tqdm to display the progress bar.
             lora_request: LoRA request to use for generation, if any.
-            multi_modal_data: Multi modal data.
 
         Returns:
             A list of `EmbeddingRequestOutput` objects containing the
             generated embeddings in the same order as the input prompts.
         """
+        if prompt_token_ids is not None or multi_modal_data is not None:
+            inputs = self._convert_v1_inputs(
+                prompts=cast(Optional[Union[str, List[str]]], prompts),
+                prompt_token_ids=prompt_token_ids,
+                multi_modal_data=multi_modal_data,
+            )
+        else:
+            inputs = cast(
+                Union[PromptStrictInputs, Sequence[PromptStrictInputs]],
+                prompts)
+
         if pooling_params is None:
             # Use default pooling params.
             pooling_params = PoolingParams()
 
-        requests_data = self._validate_and_prepare_requests(
-            prompts,
-            pooling_params,
-            prompt_token_ids,
-            lora_request,
-            multi_modal_data,
+        self._validate_and_add_requests(
+            inputs=inputs,
+            params=pooling_params,
+            lora_request=lora_request,
         )
 
-        # Add requests to the engine and run the engine
-        for request_data in requests_data:
-            self._add_request(**request_data)
+        outputs = self._run_engine(use_tqdm=use_tqdm)
+        return LLMEngine.validate_outputs(outputs, EmbeddingRequestOutput)
 
-        return self._run_engine(use_tqdm)
-
-    def _validate_and_prepare_requests(
+    # LEGACY
+    def _convert_v1_inputs(
         self,
         prompts: Optional[Union[str, List[str]]],
-        params: Union[Union[SamplingParams, PoolingParams],
-                      List[Union[SamplingParams,
-                                 PoolingParams]]],  # Unified parameter
-        prompt_token_ids: Optional[List[List[int]]] = None,
-        lora_request: Optional[LoRARequest] = None,
-        multi_modal_data: Optional[MultiModalData] = None,
-    ) -> List[dict]:
-        """Validates and prepares request data for adding to the engine.
+        prompt_token_ids: Optional[Union[List[int], List[List[int]]]],
+        multi_modal_data: Optional[MultiModalData],
+    ):
+        # skip_tokenizer_init is now checked in engine
 
-        Ensures prompts and token IDs are consistent, and returns a list of
-        dictionaries with request data for further processing.
-        """
-        if prompts is None and prompt_token_ids is None:
-            raise ValueError("Either prompts or prompt_token_ids must be "
-                             "provided.")
-        if self.llm_engine.model_config.skip_tokenizer_init \
-            and prompts is not None:
-            raise ValueError("prompts must be None if skip_tokenizer_init "
-                             "is True")
-        if isinstance(prompts, str):
-            # Convert a single prompt to a list.
-            prompts = [prompts]
-        if (prompts is not None and prompt_token_ids is not None
-                and len(prompts) != len(prompt_token_ids)):
-            raise ValueError("The lengths of prompts and prompt_token_ids "
-                             "must be the same.")
+        if prompts is not None:
+            prompts = [p["content"] for p in parse_and_batch_prompt(prompts)]
+        if prompt_token_ids is not None:
+            prompt_token_ids = [
+                p["content"] for p in parse_and_batch_prompt(prompt_token_ids)
+            ]
 
+        num_requests = None
         if prompts is not None:
             num_requests = len(prompts)
-        else:
-            assert prompt_token_ids is not None
+        if prompt_token_ids is not None:
+            if (num_requests is not None
+                    and num_requests != len(prompt_token_ids)):
+                raise ValueError("The lengths of prompts and prompt_token_ids "
+                                 "must be the same.")
+
             num_requests = len(prompt_token_ids)
+        if num_requests is None:
+            raise ValueError("Either prompts or prompt_token_ids must be "
+                             "provided.")
+
+        inputs: List[PromptInputs] = []
+        for i in range(num_requests):
+            if prompts is not None:
+                if prompt_token_ids is not None:
+                    item = TextTokensPrompt(
+                        prompt=prompts[i],
+                        prompt_token_ids=prompt_token_ids[i])
+                else:
+                    item = TextPrompt(prompt=prompts[i])
+            else:
+                if prompt_token_ids is not None:
+                    item = TokensPrompt(prompt_token_ids=prompt_token_ids[i])
+                else:
+                    raise AssertionError
+
+            if multi_modal_data is not None:
+                item["multi_modal_data"] = multi_modal_data
+
+            inputs.append(item)
+
+        return inputs
+
+    def _validate_and_add_requests(
+        self,
+        inputs: Union[PromptStrictInputs, Sequence[PromptStrictInputs]],
+        params: Union[SamplingParams, Sequence[SamplingParams], PoolingParams,
+                      Sequence[PoolingParams]],
+        lora_request: Optional[LoRARequest],
+    ) -> None:
+        if isinstance(inputs, (str, dict)):
+            # Convert a single prompt to a list.
+            inputs = [inputs]
+
+        num_requests = len(inputs)
 
         if isinstance(params, list) and len(params) != num_requests:
             raise ValueError("The lengths of prompts and params "
                              "must be the same.")
-        if multi_modal_data:
-            multi_modal_data.data = multi_modal_data.data.to(torch.float16)
 
         # Add requests to the engine.
-        requests_data = []
-        for i in range(num_requests):
-            prompt = prompts[i] if prompts is not None else None
-            token_ids = None if prompt_token_ids is None else prompt_token_ids[
-                i]
-
-            multi_modal_item = MultiModalData(
-                type=multi_modal_data.type,
-                data=multi_modal_data.data[i].unsqueeze(0),
-            ) if multi_modal_data else None
-
-            requests_data.append({
-                "prompt":
-                prompt,
-                "params":
-                params[i] if isinstance(params, list) else params,
-                "prompt_token_ids":
-                token_ids,
-                "lora_request":
-                lora_request,
-                "multi_modal_data":
-                multi_modal_item,
-            })
-
-        return requests_data
+        for i, request_inputs in enumerate(inputs):
+            self._add_request(
+                request_inputs,
+                params[i] if isinstance(params, Sequence) else params,
+                lora_request=lora_request,
+            )
 
     def _add_request(
         self,
-        prompt: Optional[str],
+        inputs: PromptInputs,
         params: Union[SamplingParams, PoolingParams],
-        prompt_token_ids: Optional[List[int]],
         lora_request: Optional[LoRARequest] = None,
-        multi_modal_data: Optional[MultiModalData] = None,
     ) -> None:
         request_id = str(next(self.request_counter))
         self.llm_engine.add_request(request_id,
-                                    prompt,
+                                    inputs,
                                     params,
-                                    prompt_token_ids,
-                                    lora_request=lora_request,
-                                    multi_modal_data=multi_modal_data)
+                                    lora_request=lora_request)
 
     def _run_engine(
-            self, use_tqdm: bool
+            self, *, use_tqdm: bool
     ) -> List[Union[RequestOutput, EmbeddingRequestOutput]]:
         # Initialize tqdm.
         if use_tqdm:
@@ -355,5 +556,4 @@ class LLM:
         # Sort the outputs by request ID.
         # This is necessary because some requests may be finished earlier than
         # its previous requests.
-        outputs = sorted(outputs, key=lambda x: int(x.request_id))
-        return outputs
+        return sorted(outputs, key=lambda x: int(x.request_id))

vllm/entrypoints/openai/serving_chat.py

@@ -176,9 +176,15 @@ class OpenAIServingChat(OpenAIServing):
         except ValueError as e:
             return self.create_error_response(str(e))
 
-        result_generator = self.engine.generate(prompt_text, sampling_params,
-                                                request_id, prompt_ids,
-                                                lora_request)
+        result_generator = self.engine.generate(
+            {
+                "prompt": prompt_text,
+                "prompt_token_ids": prompt_ids
+            },
+            sampling_params,
+            request_id,
+            lora_request,
+        )
         # Streaming response
         if request.stream:
             return self.chat_completion_stream_generator(

vllm/entrypoints/openai/serving_completion.py

@@ -119,12 +119,17 @@ class OpenAIServingCompletion(OpenAIServing):
                         truncate_prompt_tokens)
                 prompt_ids, prompt_text = prompt_formats
 
-                generators.append(
-                    self.engine.generate(prompt_text,
-                                         sampling_params,
-                                         f"{request_id}-{i}",
-                                         prompt_token_ids=prompt_ids,
-                                         lora_request=lora_request))
+                generator = self.engine.generate(
+                    {
+                        "prompt": prompt_text,
+                        "prompt_token_ids": prompt_ids
+                    },
+                    sampling_params,
+                    f"{request_id}-{i}",
+                    lora_request=lora_request,
+                )
+
+                generators.append(generator)
         except ValueError as e:
             # TODO: Use a vllm-specific Validation Error
             return self.create_error_response(str(e))

vllm/entrypoints/openai/serving_embedding.py

 import time
-from typing import AsyncIterator, List, Tuple
+from typing import AsyncIterator, List, Optional, Tuple
 
 from fastapi import Request
 
@@ -100,11 +100,16 @@ class OpenAIServingEmbedding(OpenAIServing):
 
                 prompt_ids, prompt_text = prompt_formats
 
-                generators.append(
-                    self.engine.generate(prompt_text,
-                                         pooling_params,
-                                         f"{request_id}-{i}",
-                                         prompt_token_ids=prompt_ids))
+                generator = self.engine.encode(
+                    {
+                        "prompt": prompt_text,
+                        "prompt_token_ids": prompt_ids
+                    },
+                    pooling_params,
+                    f"{request_id}-{i}",
+                )
+
+                generators.append(generator)
         except ValueError as e:
             # TODO: Use a vllm-specific Validation Error
             return self.create_error_response(str(e))
@@ -113,16 +118,21 @@ class OpenAIServingEmbedding(OpenAIServing):
             int, EmbeddingRequestOutput]] = merge_async_iterators(*generators)
 
         # Non-streaming response
-        final_res_batch: EmbeddingRequestOutput = [None] * len(prompts)
-        async for i, res in result_generator:
-            if await raw_request.is_disconnected():
-                # Abort the request if the client disconnects.
-                await self.engine.abort(f"{request_id}-{i}")
-                # TODO: Use a vllm-specific Validation Error
-                return self.create_error_response("Client disconnected")
-            final_res_batch[i] = res
-        response = request_output_to_embedding_response(
-            final_res_batch, request_id, created_time, model_name)
+        final_res_batch: List[Optional[EmbeddingRequestOutput]]
+        final_res_batch = [None] * len(prompts)
+        try:
+            async for i, res in result_generator:
+                if await raw_request.is_disconnected():
+                    # Abort the request if the client disconnects.
+                    await self.engine.abort(f"{request_id}-{i}")
+                    # TODO: Use a vllm-specific Validation Error
+                    return self.create_error_response("Client disconnected")
+                final_res_batch[i] = res
+            response = request_output_to_embedding_response(
+                final_res_batch, request_id, created_time, model_name)
+        except ValueError as e:
+            # TODO: Use a vllm-specific Validation Error
+            return self.create_error_response(str(e))
 
         return response
 

vllm/entrypoints/openai/serving_engine.py

@@ -143,7 +143,8 @@ class OpenAIServing:
         return json_str
 
     async def _check_model(
-        self, request: Union[CompletionRequest, ChatCompletionRequest]
+        self, request: Union[CompletionRequest, ChatCompletionRequest,
+                             EmbeddingRequest]
     ) -> Optional[ErrorResponse]:
         if request.model in self.served_model_names:
             return None
@@ -155,7 +156,8 @@ class OpenAIServing:
             status_code=HTTPStatus.NOT_FOUND)
 
     def _maybe_get_lora(
-        self, request: Union[CompletionRequest, ChatCompletionRequest]
+        self, request: Union[CompletionRequest, ChatCompletionRequest,
+                             EmbeddingRequest]
     ) -> Optional[LoRARequest]:
         if request.model in self.served_model_names:
             return None

vllm/inputs.py

+from typing import (TYPE_CHECKING, List, Literal, Optional, Sequence,
+                    TypedDict, Union, cast, overload)
+
+from typing_extensions import NotRequired
+
+if TYPE_CHECKING:
+    from vllm.sequence import MultiModalData
+
+
+class ParsedText(TypedDict):
+    content: str
+    is_tokens: Literal[False]
+
+
+class ParsedTokens(TypedDict):
+    content: List[int]
+    is_tokens: Literal[True]
+
+
+# https://github.com/vllm-project/vllm/pull/4028
+@overload
+def parse_and_batch_prompt(
+        prompt: Union[str, List[str]]) -> Sequence[ParsedText]:
+    ...
+
+
+@overload
+def parse_and_batch_prompt(
+        prompt: Union[List[int], List[List[int]]]) -> Sequence[ParsedTokens]:
+    ...
+
+
+def parse_and_batch_prompt(
+    prompt: Union[str, List[str], List[int], List[List[int]]],
+) -> Union[Sequence[ParsedText], Sequence[ParsedTokens]]:
+    if isinstance(prompt, str):
+        # case 1: a string
+        return [ParsedText(content=prompt, is_tokens=False)]
+
+    if isinstance(prompt, list):
+        if len(prompt) == 0:
+            raise ValueError("please provide at least one prompt")
+
+        if isinstance(prompt[0], str):
+            # case 2: array of strings
+            return [
+                ParsedText(content=elem, is_tokens=False)
+                for elem in cast(List[str], prompt)
+            ]
+        if isinstance(prompt[0], int):
+            # case 3: array of tokens
+            elem = cast(List[int], prompt)
+            return [ParsedTokens(content=elem, is_tokens=True)]
+        if isinstance(prompt[0], list):
+            if len(prompt[0]) == 0:
+                raise ValueError("please provide at least one prompt")
+
+            if isinstance(prompt[0][0], int):
+                # case 4: array of token arrays
+                return [
+                    ParsedTokens(content=elem, is_tokens=True)
+                    for elem in cast(List[List[int]], prompt)
+                ]
+
+    raise ValueError("prompt must be a string, array of strings, "
+                     "array of tokens, or array of token arrays")
+
+
+class TextPrompt(TypedDict):
+    """Schema for a text prompt."""
+
+    prompt: str
+    """The input text to be tokenized before passing to the model."""
+
+    multi_modal_data: NotRequired["MultiModalData"]
+    """
+    Optional multi-modal data to pass to the model,
+    if the model supports it.
+    """
+
+
+class TokensPrompt(TypedDict):
+    """Schema for a tokenized prompt."""
+
+    prompt_token_ids: List[int]
+    """A list of token IDs to pass to the model."""
+
+    multi_modal_data: NotRequired["MultiModalData"]
+    """
+    Optional multi-modal data to pass to the model,
+    if the model supports it.
+    """
+
+
+class TextTokensPrompt(TypedDict):
+    """It is assumed that :attr:`prompt` is consistent with
+    :attr:`prompt_token_ids`. This is currently used in
+    :class:`AsyncLLMEngine` for logging both the text and token IDs."""
+
+    prompt: str
+    """The prompt text."""
+
+    prompt_token_ids: List[int]
+    """The token IDs of the prompt. If None, we use the
+    tokenizer to convert the prompts to token IDs."""
+
+    multi_modal_data: NotRequired["MultiModalData"]
+    """
+    Optional multi-modal data to pass to the model,
+    if the model supports it.
+    """
+
+
+PromptStrictInputs = Union[str, TextPrompt, TokensPrompt]
+"""
+The inputs to the LLM, which can take one of the following forms:
+
+- A text prompt (:class:`str` or :class:`TextPrompt`)
+- A tokenized prompt (:class:`TokensPrompt`)
+"""
+
+PromptInputs = Union[str, TextPrompt, TokensPrompt, TextTokensPrompt]
+"""Same as :const:`PromptStrictInputs` but additionally accepts
+:class:`TextTokensPrompt`."""
+
+
+class LLMInputs(TypedDict):
+    prompt_token_ids: List[int]
+    prompt: Optional[str]
+    multi_modal_data: Optional["MultiModalData"]