"""Anyscale Endpoints chat wrapper. Relies heavily on ChatOpenAI."""
from __future__ import annotations
import logging
import os
import sys
from typing import TYPE_CHECKING, Dict, Optional, Set
import requests
from langchain_core.messages import BaseMessage
from langchain_core.pydantic_v1 import Field, SecretStr, root_validator
from langchain_core.utils import convert_to_secret_str, get_from_dict_or_env
from langchain_community.adapters.openai import convert_message_to_dict
from langchain_community.chat_models.openai import (
ChatOpenAI,
_import_tiktoken,
)
from langchain_community.utils.openai import is_openai_v1
if TYPE_CHECKING:
import tiktoken
logger = logging.getLogger(__name__)
DEFAULT_API_BASE = "https://api.endpoints.anyscale.com/v1"
DEFAULT_MODEL = "meta-llama/Meta-Llama-3-8B-Instruct"
[docs]class ChatAnyscale(ChatOpenAI):
"""`Anyscale` Chat large language models.
See https://www.anyscale.com/ for information about Anyscale.
To use, you should have the ``openai`` python package installed, and the
environment variable ``ANYSCALE_API_KEY`` set with your API key.
Alternatively, you can use the anyscale_api_key keyword argument.
Any parameters that are valid to be passed to the `openai.create` call can be passed
in, even if not explicitly saved on this class.
Example:
.. code-block:: python
from langchain_community.chat_models import ChatAnyscale
chat = ChatAnyscale(model_name="meta-llama/Llama-2-7b-chat-hf")
"""
@property
def _llm_type(self) -> str:
"""Return type of chat model."""
return "anyscale-chat"
@property
def lc_secrets(self) -> Dict[str, str]:
return {"anyscale_api_key": "ANYSCALE_API_KEY"}
@classmethod
def is_lc_serializable(cls) -> bool:
return False
anyscale_api_key: SecretStr = Field(default=None)
"""AnyScale Endpoints API keys."""
model_name: str = Field(default=DEFAULT_MODEL, alias="model")
"""Model name to use."""
anyscale_api_base: str = Field(default=DEFAULT_API_BASE)
"""Base URL path for API requests,
leave blank if not using a proxy or service emulator."""
anyscale_proxy: Optional[str] = None
"""To support explicit proxy for Anyscale."""
available_models: Optional[Set[str]] = None
"""Available models from Anyscale API."""
[docs] @staticmethod
def get_available_models(
anyscale_api_key: Optional[str] = None,
anyscale_api_base: str = DEFAULT_API_BASE,
) -> Set[str]:
"""Get available models from Anyscale API."""
try:
anyscale_api_key = anyscale_api_key or os.environ["ANYSCALE_API_KEY"]
except KeyError as e:
raise ValueError(
"Anyscale API key must be passed as keyword argument or "
"set in environment variable ANYSCALE_API_KEY.",
) from e
models_url = f"{anyscale_api_base}/models"
models_response = requests.get(
models_url,
headers={
"Authorization": f"Bearer {anyscale_api_key}",
},
)
if models_response.status_code != 200:
raise ValueError(
f"Error getting models from {models_url}: "
f"{models_response.status_code}",
)
return {model["id"] for model in models_response.json()["data"]}
@root_validator(pre=True)
def validate_environment(cls, values: dict) -> dict:
"""Validate that api key and python package exists in environment."""
values["anyscale_api_key"] = convert_to_secret_str(
get_from_dict_or_env(
values,
"anyscale_api_key",
"ANYSCALE_API_KEY",
)
)
values["anyscale_api_base"] = get_from_dict_or_env(
values,
"anyscale_api_base",
"ANYSCALE_API_BASE",
default=DEFAULT_API_BASE,
)
values["openai_proxy"] = get_from_dict_or_env(
values,
"anyscale_proxy",
"ANYSCALE_PROXY",
default="",
)
try:
import openai
except ImportError as e:
raise ImportError(
"Could not import openai python package. "
"Please install it with `pip install openai`.",
) from e
try:
if is_openai_v1():
client_params = {
"api_key": values["anyscale_api_key"].get_secret_value(),
"base_url": values["anyscale_api_base"],
# To do: future support
# "organization": values["openai_organization"],
# "timeout": values["request_timeout"],
# "max_retries": values["max_retries"],
# "default_headers": values["default_headers"],
# "default_query": values["default_query"],
# "http_client": values["http_client"],
}
if not values.get("client"):
values["client"] = openai.OpenAI(**client_params).chat.completions
if not values.get("async_client"):
values["async_client"] = openai.AsyncOpenAI(
**client_params
).chat.completions
else:
values["openai_api_base"] = values["anyscale_api_base"]
values["openai_api_key"] = values["anyscale_api_key"].get_secret_value()
values["client"] = openai.ChatCompletion
except AttributeError as exc:
raise ValueError(
"`openai` has no `ChatCompletion` attribute, this is likely "
"due to an old version of the openai package. Try upgrading it "
"with `pip install --upgrade openai`.",
) from exc
if "model_name" not in values.keys():
values["model_name"] = DEFAULT_MODEL
model_name = values["model_name"]
available_models = cls.get_available_models(
values["anyscale_api_key"].get_secret_value(),
values["anyscale_api_base"],
)
if model_name not in available_models:
raise ValueError(
f"Model name {model_name} not found in available models: "
f"{available_models}.",
)
values["available_models"] = available_models
return values
def _get_encoding_model(self) -> tuple[str, tiktoken.Encoding]:
tiktoken_ = _import_tiktoken()
if self.tiktoken_model_name is not None:
model = self.tiktoken_model_name
else:
model = self.model_name
# Returns the number of tokens used by a list of messages.
try:
encoding = tiktoken_.encoding_for_model("gpt-3.5-turbo-0301")
except KeyError:
logger.warning("Warning: model not found. Using cl100k_base encoding.")
model = "cl100k_base"
encoding = tiktoken_.get_encoding(model)
return model, encoding
[docs] def get_num_tokens_from_messages(self, messages: list[BaseMessage]) -> int:
"""Calculate num tokens with tiktoken package.
Official documentation: https://github.com/openai/openai-cookbook/blob/main/examples/How_to_format_inputs_to_ChatGPT_models.ipynb
"""
if sys.version_info[1] <= 7:
return super().get_num_tokens_from_messages(messages)
model, encoding = self._get_encoding_model()
tokens_per_message = 3
tokens_per_name = 1
num_tokens = 0
messages_dict = [convert_message_to_dict(m) for m in messages]
for message in messages_dict:
num_tokens += tokens_per_message
for key, value in message.items():
# Cast str(value) in case the message value is not a string
# This occurs with function messages
num_tokens += len(encoding.encode(str(value)))
if key == "name":
num_tokens += tokens_per_name
# every reply is primed with <im_start>assistant
num_tokens += 3
return num_tokens
