import json # type: ignore[import-not-found]
import logging
import os
from typing import Any, AsyncIterator, Dict, Iterator, List, Mapping, Optional
from langchain_core.callbacks import (
AsyncCallbackManagerForLLMRun,
CallbackManagerForLLMRun,
)
from langchain_core.language_models.llms import LLM
from langchain_core.outputs import GenerationChunk
from langchain_core.pydantic_v1 import Field, root_validator
from langchain_core.utils import get_from_dict_or_env, get_pydantic_field_names
logger = logging.getLogger(__name__)
VALID_TASKS = (
"text2text-generation",
"text-generation",
"summarization",
"conversational",
)
[docs]class HuggingFaceEndpoint(LLM):
"""
HuggingFace Endpoint.
To use this class, you should have installed the ``huggingface_hub`` package, and
the environment variable ``HUGGINGFACEHUB_API_TOKEN`` set with your API token,
or given as a named parameter to the constructor.
Example:
.. code-block:: python
# Basic Example (no streaming)
llm = HuggingFaceEndpoint(
endpoint_url="http://localhost:8010/",
max_new_tokens=512,
top_k=10,
top_p=0.95,
typical_p=0.95,
temperature=0.01,
repetition_penalty=1.03,
huggingfacehub_api_token="my-api-key"
)
print(llm.invoke("What is Deep Learning?"))
# Streaming response example
from langchain_core.callbacks.streaming_stdout import StreamingStdOutCallbackHandler
callbacks = [StreamingStdOutCallbackHandler()]
llm = HuggingFaceEndpoint(
endpoint_url="http://localhost:8010/",
max_new_tokens=512,
top_k=10,
top_p=0.95,
typical_p=0.95,
temperature=0.01,
repetition_penalty=1.03,
callbacks=callbacks,
streaming=True,
huggingfacehub_api_token="my-api-key"
)
print(llm.invoke("What is Deep Learning?"))
""" # noqa: E501
endpoint_url: Optional[str] = None
"""Endpoint URL to use. If repo_id is not specified then this needs to given or
should be pass as env variable in `HF_INFERENCE_ENDPOINT`"""
repo_id: Optional[str] = None
"""Repo to use. If endpoint_url is not specified then this needs to given"""
huggingfacehub_api_token: Optional[str] = None
max_new_tokens: int = 512
"""Maximum number of generated tokens"""
top_k: Optional[int] = None
"""The number of highest probability vocabulary tokens to keep for
top-k-filtering."""
top_p: Optional[float] = 0.95
"""If set to < 1, only the smallest set of most probable tokens with probabilities
that add up to `top_p` or higher are kept for generation."""
typical_p: Optional[float] = 0.95
"""Typical Decoding mass. See [Typical Decoding for Natural Language
Generation](https://arxiv.org/abs/2202.00666) for more information."""
temperature: Optional[float] = 0.8
"""The value used to module the logits distribution."""
repetition_penalty: Optional[float] = None
"""The parameter for repetition penalty. 1.0 means no penalty.
See [this paper](https://arxiv.org/pdf/1909.05858.pdf) for more details."""
return_full_text: bool = False
"""Whether to prepend the prompt to the generated text"""
truncate: Optional[int] = None
"""Truncate inputs tokens to the given size"""
stop_sequences: List[str] = Field(default_factory=list)
"""Stop generating tokens if a member of `stop_sequences` is generated"""
seed: Optional[int] = None
"""Random sampling seed"""
inference_server_url: str = ""
"""text-generation-inference instance base url"""
timeout: int = 120
"""Timeout in seconds"""
streaming: bool = False
"""Whether to generate a stream of tokens asynchronously"""
do_sample: bool = False
"""Activate logits sampling"""
watermark: bool = False
"""Watermarking with [A Watermark for Large Language Models]
(https://arxiv.org/abs/2301.10226)"""
server_kwargs: Dict[str, Any] = Field(default_factory=dict)
"""Holds any text-generation-inference server parameters not explicitly specified"""
model_kwargs: Dict[str, Any] = Field(default_factory=dict)
"""Holds any model parameters valid for `call` not explicitly specified"""
model: str
client: Any
async_client: Any
task: Optional[str] = None
"""Task to call the model with.
Should be a task that returns `generated_text` or `summary_text`."""
class Config:
"""Configuration for this pydantic object."""
extra = "forbid"
@root_validator(pre=True)
def build_extra(cls, values: Dict[str, Any]) -> Dict[str, Any]:
"""Build extra kwargs from additional params that were passed in."""
all_required_field_names = get_pydantic_field_names(cls)
extra = values.get("model_kwargs", {})
for field_name in list(values):
if field_name in extra:
raise ValueError(f"Found {field_name} supplied twice.")
if field_name not in all_required_field_names:
logger.warning(
f"""WARNING! {field_name} is not default parameter.
{field_name} was transferred to model_kwargs.
Please make sure that {field_name} is what you intended."""
)
extra[field_name] = values.pop(field_name)
invalid_model_kwargs = all_required_field_names.intersection(extra.keys())
if invalid_model_kwargs:
raise ValueError(
f"Parameters {invalid_model_kwargs} should be specified explicitly. "
f"Instead they were passed in as part of `model_kwargs` parameter."
)
values["model_kwargs"] = extra
# to correctly create the InferenceClient and AsyncInferenceClient
# in validate_environment, we need to populate values["model"].
# from InferenceClient docstring:
# model (`str`, `optional`):
# The model to run inference with. Can be a model id hosted on the Hugging
# Face Hub, e.g. `bigcode/starcoder`
# or a URL to a deployed Inference Endpoint. Defaults to None, in which
# case a recommended model is
# automatically selected for the task.
# this string could be in 3 places of descending priority:
# 2. values["model"] or values["endpoint_url"] or values["repo_id"]
# (equal priority - don't allow both set)
# 3. values["HF_INFERENCE_ENDPOINT"] (if none above set)
model = values.get("model")
endpoint_url = values.get("endpoint_url")
repo_id = values.get("repo_id")
if sum([bool(model), bool(endpoint_url), bool(repo_id)]) > 1:
raise ValueError(
"Please specify either a `model` OR an `endpoint_url` OR a `repo_id`,"
"not more than one."
)
values["model"] = (
model or endpoint_url or repo_id or os.environ.get("HF_INFERENCE_ENDPOINT")
)
if not values["model"]:
raise ValueError(
"Please specify a `model` or an `endpoint_url` or a `repo_id` for the "
"model."
)
return values
@root_validator(pre=False, skip_on_failure=True)
def validate_environment(cls, values: Dict) -> Dict:
"""Validate that package is installed and that the API token is valid."""
try:
from huggingface_hub import login # type: ignore[import]
except ImportError:
raise ImportError(
"Could not import huggingface_hub python package. "
"Please install it with `pip install huggingface_hub`."
)
values["huggingfacehub_api_token"] = get_from_dict_or_env(
values, "huggingfacehub_api_token", "HUGGINGFACEHUB_API_TOKEN", None
)
huggingfacehub_api_token = get_from_dict_or_env(
values, "huggingfacehub_api_token", "HF_TOKEN", None
)
if huggingfacehub_api_token is not None:
try:
login(token=huggingfacehub_api_token)
except Exception as e:
raise ValueError(
"Could not authenticate with huggingface_hub. "
"Please check your API token."
) from e
from huggingface_hub import AsyncInferenceClient, InferenceClient
values["client"] = InferenceClient(
model=values["model"],
timeout=values["timeout"],
token=huggingfacehub_api_token,
**values["server_kwargs"],
)
values["async_client"] = AsyncInferenceClient(
model=values["model"],
timeout=values["timeout"],
token=huggingfacehub_api_token,
**values["server_kwargs"],
)
return values
@property
def _default_params(self) -> Dict[str, Any]:
"""Get the default parameters for calling text generation inference API."""
return {
"max_new_tokens": self.max_new_tokens,
"top_k": self.top_k,
"top_p": self.top_p,
"typical_p": self.typical_p,
"temperature": self.temperature,
"repetition_penalty": self.repetition_penalty,
"return_full_text": self.return_full_text,
"truncate": self.truncate,
"stop_sequences": self.stop_sequences,
"seed": self.seed,
"do_sample": self.do_sample,
"watermark": self.watermark,
**self.model_kwargs,
}
@property
def _identifying_params(self) -> Mapping[str, Any]:
"""Get the identifying parameters."""
_model_kwargs = self.model_kwargs or {}
return {
**{"endpoint_url": self.endpoint_url, "task": self.task},
**{"model_kwargs": _model_kwargs},
}
@property
def _llm_type(self) -> str:
"""Return type of llm."""
return "huggingface_endpoint"
def _invocation_params(
self, runtime_stop: Optional[List[str]], **kwargs: Any
) -> Dict[str, Any]:
params = {**self._default_params, **kwargs}
params["stop_sequences"] = params["stop_sequences"] + (runtime_stop or [])
return params
def _call(
self,
prompt: str,
stop: Optional[List[str]] = None,
run_manager: Optional[CallbackManagerForLLMRun] = None,
**kwargs: Any,
) -> str:
"""Call out to HuggingFace Hub's inference endpoint."""
invocation_params = self._invocation_params(stop, **kwargs)
if self.streaming:
completion = ""
for chunk in self._stream(prompt, stop, run_manager, **invocation_params):
completion += chunk.text
return completion
else:
invocation_params["stop"] = invocation_params[
"stop_sequences"
] # porting 'stop_sequences' into the 'stop' argument
response = self.client.post(
json={"inputs": prompt, "parameters": invocation_params},
stream=False,
task=self.task,
)
response_text = json.loads(response.decode())[0]["generated_text"]
# Maybe the generation has stopped at one of the stop sequences:
# then we remove this stop sequence from the end of the generated text
for stop_seq in invocation_params["stop_sequences"]:
if response_text[-len(stop_seq) :] == stop_seq:
response_text = response_text[: -len(stop_seq)]
return response_text
async def _acall(
self,
prompt: str,
stop: Optional[List[str]] = None,
run_manager: Optional[AsyncCallbackManagerForLLMRun] = None,
**kwargs: Any,
) -> str:
invocation_params = self._invocation_params(stop, **kwargs)
if self.streaming:
completion = ""
async for chunk in self._astream(
prompt, stop, run_manager, **invocation_params
):
completion += chunk.text
return completion
else:
invocation_params["stop"] = invocation_params["stop_sequences"]
response = await self.async_client.post(
json={"inputs": prompt, "parameters": invocation_params},
stream=False,
task=self.task,
)
response_text = json.loads(response.decode())[0]["generated_text"]
# Maybe the generation has stopped at one of the stop sequences:
# then remove this stop sequence from the end of the generated text
for stop_seq in invocation_params["stop_sequences"]:
if response_text[-len(stop_seq) :] == stop_seq:
response_text = response_text[: -len(stop_seq)]
return response_text
def _stream(
self,
prompt: str,
stop: Optional[List[str]] = None,
run_manager: Optional[CallbackManagerForLLMRun] = None,
**kwargs: Any,
) -> Iterator[GenerationChunk]:
invocation_params = self._invocation_params(stop, **kwargs)
for response in self.client.text_generation(
prompt, **invocation_params, stream=True
):
# identify stop sequence in generated text, if any
stop_seq_found: Optional[str] = None
for stop_seq in invocation_params["stop_sequences"]:
if stop_seq in response:
stop_seq_found = stop_seq
# identify text to yield
text: Optional[str] = None
if stop_seq_found:
text = response[: response.index(stop_seq_found)]
else:
text = response
# yield text, if any
if text:
chunk = GenerationChunk(text=text)
if run_manager:
run_manager.on_llm_new_token(chunk.text)
yield chunk
# break if stop sequence found
if stop_seq_found:
break
async def _astream(
self,
prompt: str,
stop: Optional[List[str]] = None,
run_manager: Optional[AsyncCallbackManagerForLLMRun] = None,
**kwargs: Any,
) -> AsyncIterator[GenerationChunk]:
invocation_params = self._invocation_params(stop, **kwargs)
async for response in await self.async_client.text_generation(
prompt, **invocation_params, stream=True
):
# identify stop sequence in generated text, if any
stop_seq_found: Optional[str] = None
for stop_seq in invocation_params["stop_sequences"]:
if stop_seq in response:
stop_seq_found = stop_seq
# identify text to yield
text: Optional[str] = None
if stop_seq_found:
text = response[: response.index(stop_seq_found)]
else:
text = response
# yield text, if any
if text:
chunk = GenerationChunk(text=text)
if run_manager:
await run_manager.on_llm_new_token(chunk.text)
yield chunk
# break if stop sequence found
if stop_seq_found:
break
