import json import os import re import warnings from operator import itemgetter from typing import ( Any, AsyncIterator, Callable, Dict, Iterator, List, Literal, Mapping, Optional, Sequence, Tuple, Type, TypedDict, Union, cast, ) import anthropic from langchain_core._api import beta, deprecated from langchain_core.callbacks import ( AsyncCallbackManagerForLLMRun, CallbackManagerForLLMRun, ) from langchain_core.language_models import LanguageModelInput from langchain_core.language_models.chat_models import ( BaseChatModel, LangSmithParams, agenerate_from_stream, generate_from_stream, ) from langchain_core.messages import ( AIMessage, AIMessageChunk, BaseMessage, HumanMessage, SystemMessage, ToolCall, ToolMessage, ) from langchain_core.outputs import ChatGeneration, ChatGenerationChunk, ChatResult from langchain_core.pydantic_v1 import BaseModel, Field, SecretStr, root_validator from langchain_core.runnables import ( Runnable, RunnableMap, RunnablePassthrough, ) from langchain_core.tools import BaseTool from langchain_core.utils import ( build_extra_kwargs, convert_to_secret_str, get_pydantic_field_names, ) from langchain_core.utils.function_calling import convert_to_openai_tool from langchain_anthropic.output_parsers import ToolsOutputParser, extract_tool_calls _message_type_lookups = { "human": "user", "ai": "assistant", "AIMessageChunk": "assistant", "HumanMessageChunk": "user", } def _format_image(image_url: str) -> Dict: """ Formats an image of format data:image/jpeg;base64,{b64_string} to a dict for anthropic api { "type": "base64", "media_type": "image/jpeg", "data": "/9j/4AAQSkZJRg...", } And throws an error if it's not a b64 image """ regex = r"^data:(?Pimage/.+);base64,(?P.+)$" match = re.match(regex, image_url) if match is None: raise ValueError( "Anthropic only supports base64-encoded images currently." " Example: data:image/png;base64,'/9j/4AAQSk'..." ) return { "type": "base64", "media_type": match.group("media_type"), "data": match.group("data"), } def _merge_messages( messages: Sequence[BaseMessage], ) -> List[Union[SystemMessage, AIMessage, HumanMessage]]: """Merge runs of human/tool messages into single human messages with content blocks.""" # noqa: E501 merged: list = [] for curr in messages: curr = curr.copy(deep=True) if isinstance(curr, ToolMessage): if isinstance(curr.content, str): curr = HumanMessage( [ { "type": "tool_result", "content": curr.content, "tool_use_id": curr.tool_call_id, } ] ) else: curr = HumanMessage(curr.content) last = merged[-1] if merged else None if isinstance(last, HumanMessage) and isinstance(curr, HumanMessage): if isinstance(last.content, str): new_content: List = [{"type": "text", "text": last.content}] else: new_content = last.content if isinstance(curr.content, str): new_content.append({"type": "text", "text": curr.content}) else: new_content.extend(curr.content) last.content = new_content else: merged.append(curr) return merged def _format_messages(messages: List[BaseMessage]) -> Tuple[Optional[str], List[Dict]]: """Format messages for anthropic.""" """ [ { "role": _message_type_lookups[m.type], "content": [_AnthropicMessageContent(text=m.content).dict()], } for m in messages ] """ system: Optional[str] = None formatted_messages: List[Dict] = [] merged_messages = _merge_messages(messages) for i, message in enumerate(merged_messages): if message.type == "system": if i != 0: raise ValueError("System message must be at beginning of message list.") if not isinstance(message.content, str): raise ValueError( "System message must be a string, " f"instead was: {type(message.content)}" ) system = message.content continue role = _message_type_lookups[message.type] content: Union[str, List] if not isinstance(message.content, str): # parse as dict assert isinstance( message.content, list ), "Anthropic message content must be str or list of dicts" # populate content content = [] for item in message.content: if isinstance(item, str): content.append( { "type": "text", "text": item, } ) elif isinstance(item, dict): if "type" not in item: raise ValueError("Dict content item must have a type key") elif item["type"] == "image_url": # convert format source = _format_image(item["image_url"]["url"]) content.append( { "type": "image", "source": source, } ) elif item["type"] == "tool_use": item.pop("text", None) content.append(item) elif item["type"] == "text": text = item.get("text", "") # Only add non-empty strings for now as empty ones are not # accepted. # https://github.com/anthropics/anthropic-sdk-python/issues/461 if text.strip(): content.append( { "type": "text", "text": text, } ) else: content.append(item) else: raise ValueError( f"Content items must be str or dict, instead was: {type(item)}" ) elif ( isinstance(message, AIMessage) and not isinstance(message.content, list) and message.tool_calls ): content = ( [] if not message.content else [{"type": "text", "text": message.content}] ) # Note: Anthropic can't have invalid tool calls as presently defined, # since the model already returns dicts args not JSON strings, and invalid # tool calls are those with invalid JSON for args. content += _lc_tool_calls_to_anthropic_tool_use_blocks(message.tool_calls) else: content = message.content formatted_messages.append( { "role": role, "content": content, } ) return system, formatted_messages class ChatAnthropic(BaseChatModel): """Anthropic chat model. To use, you should have the environment variable ``ANTHROPIC_API_KEY`` set with your API key, or pass it as a named parameter to the constructor. Example: .. code-block:: python from langchain_anthropic import ChatAnthropic model = ChatAnthropic(model='claude-3-opus-20240229') """ class Config: """Configuration for this pydantic object.""" allow_population_by_field_name = True _client: anthropic.Client = Field(default=None) _async_client: anthropic.AsyncClient = Field(default=None) model: str = Field(alias="model_name") """Model name to use.""" max_tokens: int = Field(default=1024, alias="max_tokens_to_sample") """Denotes the number of tokens to predict per generation.""" temperature: Optional[float] = None """A non-negative float that tunes the degree of randomness in generation.""" top_k: Optional[int] = None """Number of most likely tokens to consider at each step.""" top_p: Optional[float] = None """Total probability mass of tokens to consider at each step.""" default_request_timeout: Optional[float] = Field(None, alias="timeout") """Timeout for requests to Anthropic Completion API.""" # sdk default = 2: https://github.com/anthropics/anthropic-sdk-python?tab=readme-ov-file#retries max_retries: int = 2 """Number of retries allowed for requests sent to the Anthropic Completion API.""" anthropic_api_url: Optional[str] = None anthropic_api_key: Optional[SecretStr] = Field(None, alias="api_key") """Automatically read from env var `ANTHROPIC_API_KEY` if not provided.""" default_headers: Optional[Mapping[str, str]] = None """Headers to pass to the Anthropic clients, will be used for every API call.""" model_kwargs: Dict[str, Any] = Field(default_factory=dict) streaming: bool = False """Whether to use streaming or not.""" @property def _llm_type(self) -> str: """Return type of chat model.""" return "anthropic-chat" @property def lc_secrets(self) -> Dict[str, str]: return {"anthropic_api_key": "ANTHROPIC_API_KEY"} @classmethod def is_lc_serializable(cls) -> bool: return True @classmethod def get_lc_namespace(cls) -> List[str]: """Get the namespace of the langchain object.""" return ["langchain", "chat_models", "anthropic"] @property def _identifying_params(self) -> Dict[str, Any]: """Get the identifying parameters.""" return { "model": self.model, "max_tokens": self.max_tokens, "temperature": self.temperature, "top_k": self.top_k, "top_p": self.top_p, "model_kwargs": self.model_kwargs, "streaming": self.streaming, "max_retries": self.max_retries, "default_request_timeout": self.default_request_timeout, } def _get_ls_params( self, stop: Optional[List[str]] = None, **kwargs: Any ) -> LangSmithParams: """Get the parameters used to invoke the model.""" params = self._get_invocation_params(stop=stop, **kwargs) ls_params = LangSmithParams( ls_provider="anthropic", ls_model_name=self.model, ls_model_type="chat", ls_temperature=params.get("temperature", self.temperature), ) if ls_max_tokens := params.get("max_tokens", self.max_tokens): ls_params["ls_max_tokens"] = ls_max_tokens if ls_stop := stop or params.get("stop", None): ls_params["ls_stop"] = ls_stop return ls_params @root_validator(pre=True) def build_extra(cls, values: Dict) -> Dict: extra = values.get("model_kwargs", {}) all_required_field_names = get_pydantic_field_names(cls) values["model_kwargs"] = build_extra_kwargs( extra, values, all_required_field_names ) return values @root_validator() def validate_environment(cls, values: Dict) -> Dict: anthropic_api_key = convert_to_secret_str( values.get("anthropic_api_key") or os.environ.get("ANTHROPIC_API_KEY") or "" ) values["anthropic_api_key"] = anthropic_api_key api_key = anthropic_api_key.get_secret_value() api_url = ( values.get("anthropic_api_url") or os.environ.get("ANTHROPIC_API_URL") or "https://api.anthropic.com" ) values["anthropic_api_url"] = api_url client_params = { "api_key": api_key, "base_url": api_url, "max_retries": values["max_retries"], "default_headers": values.get("default_headers"), } # value <= 0 indicates the param should be ignored. None is a meaningful value # for Anthropic client and treated differently than not specifying the param at # all. if ( values["default_request_timeout"] is None or values["default_request_timeout"] > 0 ): client_params["timeout"] = values["default_request_timeout"] values["_client"] = anthropic.Client(**client_params) values["_async_client"] = anthropic.AsyncClient(**client_params) return values def _format_params( self, *, messages: List[BaseMessage], stop: Optional[List[str]] = None, **kwargs: Dict, ) -> Dict: # get system prompt if any system, formatted_messages = _format_messages(messages) rtn = { "model": self.model, "max_tokens": self.max_tokens, "messages": formatted_messages, "temperature": self.temperature, "top_k": self.top_k, "top_p": self.top_p, "stop_sequences": stop, "system": system, **self.model_kwargs, **kwargs, } rtn = {k: v for k, v in rtn.items() if v is not None} return rtn def _stream( self, messages: List[BaseMessage], stop: Optional[List[str]] = None, run_manager: Optional[CallbackManagerForLLMRun] = None, **kwargs: Any, ) -> Iterator[ChatGenerationChunk]: params = self._format_params(messages=messages, stop=stop, **kwargs) if _tools_in_params(params): result = self._generate( messages, stop=stop, run_manager=run_manager, **kwargs ) message = result.generations[0].message if isinstance(message, AIMessage) and message.tool_calls is not None: tool_call_chunks = [ { "name": tool_call["name"], "args": json.dumps(tool_call["args"]), "id": tool_call["id"], "index": idx, } for idx, tool_call in enumerate(message.tool_calls) ] message_chunk = AIMessageChunk( content=message.content, tool_call_chunks=tool_call_chunks, ) yield ChatGenerationChunk(message=message_chunk) else: yield cast(ChatGenerationChunk, result.generations[0]) return with self._client.messages.stream(**params) as stream: for text in stream.text_stream: chunk = ChatGenerationChunk(message=AIMessageChunk(content=text)) if run_manager: run_manager.on_llm_new_token(text, chunk=chunk) yield chunk async def _astream( self, messages: List[BaseMessage], stop: Optional[List[str]] = None, run_manager: Optional[AsyncCallbackManagerForLLMRun] = None, **kwargs: Any, ) -> AsyncIterator[ChatGenerationChunk]: params = self._format_params(messages=messages, stop=stop, **kwargs) if _tools_in_params(params): warnings.warn("stream: Tool use is not yet supported in streaming mode.") result = await self._agenerate( messages, stop=stop, run_manager=run_manager, **kwargs ) message = result.generations[0].message if isinstance(message, AIMessage) and message.tool_calls is not None: tool_call_chunks = [ { "name": tool_call["name"], "args": json.dumps(tool_call["args"]), "id": tool_call["id"], "index": idx, } for idx, tool_call in enumerate(message.tool_calls) ] message_chunk = AIMessageChunk( content=message.content, tool_call_chunks=tool_call_chunks, ) yield ChatGenerationChunk(message=message_chunk) else: yield cast(ChatGenerationChunk, result.generations[0]) return async with self._async_client.messages.stream(**params) as stream: async for text in stream.text_stream: chunk = ChatGenerationChunk(message=AIMessageChunk(content=text)) if run_manager: await run_manager.on_llm_new_token(text, chunk=chunk) yield chunk def _format_output(self, data: Any, **kwargs: Any) -> ChatResult: data_dict = data.model_dump() content = data_dict["content"] llm_output = { k: v for k, v in data_dict.items() if k not in ("content", "role", "type") } if len(content) == 1 and content[0]["type"] == "text": msg = AIMessage(content=content[0]["text"]) elif any(block["type"] == "tool_use" for block in content): tool_calls = extract_tool_calls(content) msg = AIMessage( content=content, tool_calls=tool_calls, ) else: msg = AIMessage(content=content) return ChatResult( generations=[ChatGeneration(message=msg)], llm_output=llm_output, ) def _generate( self, messages: List[BaseMessage], stop: Optional[List[str]] = None, run_manager: Optional[CallbackManagerForLLMRun] = None, **kwargs: Any, ) -> ChatResult: params = self._format_params(messages=messages, stop=stop, **kwargs) if self.streaming: if _tools_in_params(params): warnings.warn( "stream: Tool use is not yet supported in streaming mode." ) else: stream_iter = self._stream( messages, stop=stop, run_manager=run_manager, **kwargs ) return generate_from_stream(stream_iter) if _tools_in_params(params): data = self._client.beta.tools.messages.create(**params) else: data = self._client.messages.create(**params) return self._format_output(data, **kwargs) async def _agenerate( self, messages: List[BaseMessage], stop: Optional[List[str]] = None, run_manager: Optional[AsyncCallbackManagerForLLMRun] = None, **kwargs: Any, ) -> ChatResult: params = self._format_params(messages=messages, stop=stop, **kwargs) if self.streaming: if _tools_in_params(params): warnings.warn( "stream: Tool use is not yet supported in streaming mode." ) else: stream_iter = self._astream( messages, stop=stop, run_manager=run_manager, **kwargs ) return await agenerate_from_stream(stream_iter) if _tools_in_params(params): data = await self._async_client.beta.tools.messages.create(**params) else: data = await self._async_client.messages.create(**params) return self._format_output(data, **kwargs) @beta() def bind_tools( self, tools: Sequence[Union[Dict[str, Any], Type[BaseModel], Callable, BaseTool]], *, tool_choice: Optional[ Union[Dict[str, str], Literal["any", "auto"], str] ] = None, **kwargs: Any, ) -> Runnable[LanguageModelInput, BaseMessage]: """Bind tool-like objects to this chat model. Args: tools: A list of tool definitions to bind to this chat model. Can be a dictionary, pydantic model, callable, or BaseTool. Pydantic models, callables, and BaseTools will be automatically converted to their schema dictionary representation. tool_choice: Which tool to require the model to call. Options are: name of the tool (str): calls corresponding tool; "auto" or None: automatically selects a tool (including no tool); "any": force at least one tool to be called; or a dict of the form: {"type": "tool", "name": "tool_name"}, or {"type: "any"}, or {"type: "auto"}; **kwargs: Any additional parameters to bind. Example: .. code-block:: python from langchain_anthropic import ChatAnthropic from langchain_core.pydantic_v1 import BaseModel, Field class GetWeather(BaseModel): '''Get the current weather in a given location''' location: str = Field(..., description="The city and state, e.g. San Francisco, CA") class GetPrice(BaseModel): '''Get the price of a specific product.''' product: str = Field(..., description="The product to look up.") llm = ChatAnthropic(model="claude-3-opus-20240229", temperature=0) llm_with_tools = llm.bind_tools([GetWeather, GetPrice]) llm_with_tools.invoke("what is the weather like in San Francisco",) # -> AIMessage( # content=[ # {'text': '\nBased on the user\'s question, the relevant function to call is GetWeather, which requires the "location" parameter.\n\nThe user has directly specified the location as "San Francisco". Since San Francisco is a well known city, I can reasonably infer they mean San Francisco, CA without needing the state specified.\n\nAll the required parameters are provided, so I can proceed with the API call.\n', 'type': 'text'}, # {'text': None, 'type': 'tool_use', 'id': 'toolu_01SCgExKzQ7eqSkMHfygvYuu', 'name': 'GetWeather', 'input': {'location': 'San Francisco, CA'}} # ], # response_metadata={'id': 'msg_01GM3zQtoFv8jGQMW7abLnhi', 'model': 'claude-3-opus-20240229', 'stop_reason': 'tool_use', 'stop_sequence': None, 'usage': {'input_tokens': 487, 'output_tokens': 145}}, # id='run-87b1331e-9251-4a68-acef-f0a018b639cc-0' # ) Example — force tool call with tool_choice 'any': .. code-block:: python from langchain_anthropic import ChatAnthropic from langchain_core.pydantic_v1 import BaseModel, Field class GetWeather(BaseModel): '''Get the current weather in a given location''' location: str = Field(..., description="The city and state, e.g. San Francisco, CA") class GetPrice(BaseModel): '''Get the price of a specific product.''' product: str = Field(..., description="The product to look up.") llm = ChatAnthropic(model="claude-3-opus-20240229", temperature=0) llm_with_tools = llm.bind_tools([GetWeather, GetPrice], tool_choice="any") llm_with_tools.invoke("what is the weather like in San Francisco",) Example — force specific tool call with tool_choice '': .. code-block:: python from langchain_anthropic import ChatAnthropic from langchain_core.pydantic_v1 import BaseModel, Field class GetWeather(BaseModel): '''Get the current weather in a given location''' location: str = Field(..., description="The city and state, e.g. San Francisco, CA") class GetPrice(BaseModel): '''Get the price of a specific product.''' product: str = Field(..., description="The product to look up.") llm = ChatAnthropic(model="claude-3-opus-20240229", temperature=0) llm_with_tools = llm.bind_tools([GetWeather, GetPrice], tool_choice="GetWeather") llm_with_tools.invoke("what is the weather like in San Francisco",) """ # noqa: E501 formatted_tools = [convert_to_anthropic_tool(tool) for tool in tools] if not tool_choice: pass elif isinstance(tool_choice, dict): kwargs["tool_choice"] = tool_choice elif isinstance(tool_choice, str) and tool_choice in ("any", "auto"): kwargs["tool_choice"] = {"type": tool_choice} elif isinstance(tool_choice, str): kwargs["tool_choice"] = {"type": "tool", "name": tool_choice} else: raise ValueError( f"Unrecognized 'tool_choice' type {tool_choice=}. Expected dict, " f"str, or None." ) return self.bind(tools=formatted_tools, **kwargs) def with_structured_output( self, schema: Union[Dict, Type[BaseModel]], *, include_raw: bool = False, **kwargs: Any, ) -> Runnable[LanguageModelInput, Union[Dict, BaseModel]]: """Model wrapper that returns outputs formatted to match the given schema. Args: schema: The output schema as a dict or a Pydantic class. If a Pydantic class then the model output will be an object of that class. If a dict then the model output will be a dict. With a Pydantic class the returned attributes will be validated, whereas with a dict they will not be. include_raw: If False then only the parsed structured output is returned. If an error occurs during model output parsing it will be raised. If True then both the raw model response (a BaseMessage) and the parsed model response will be returned. If an error occurs during output parsing it will be caught and returned as well. The final output is always a dict with keys "raw", "parsed", and "parsing_error". Returns: A Runnable that takes any ChatModel input. The output type depends on include_raw and schema. If include_raw is True then output is a dict with keys: raw: BaseMessage, parsed: Optional[_DictOrPydantic], parsing_error: Optional[BaseException], If include_raw is False and schema is a Dict then the runnable outputs a Dict. If include_raw is False and schema is a Type[BaseModel] then the runnable outputs a BaseModel. Example: Pydantic schema (include_raw=False): .. code-block:: python from langchain_anthropic import ChatAnthropic from langchain_core.pydantic_v1 import BaseModel class AnswerWithJustification(BaseModel): '''An answer to the user question along with justification for the answer.''' answer: str justification: str llm = ChatAnthropic(model="claude-3-opus-20240229", temperature=0) structured_llm = llm.with_structured_output(AnswerWithJustification) structured_llm.invoke("What weighs more a pound of bricks or a pound of feathers") # -> AnswerWithJustification( # answer='They weigh the same', # justification='Both a pound of bricks and a pound of feathers weigh one pound. The weight is the same, but the volume or density of the objects may differ.' # ) Example: Pydantic schema (include_raw=True): .. code-block:: python from langchain_anthropic import ChatAnthropic from langchain_core.pydantic_v1 import BaseModel class AnswerWithJustification(BaseModel): '''An answer to the user question along with justification for the answer.''' answer: str justification: str llm = ChatAnthropic(model="claude-3-opus-20240229", temperature=0) structured_llm = llm.with_structured_output(AnswerWithJustification, include_raw=True) structured_llm.invoke("What weighs more a pound of bricks or a pound of feathers") # -> { # 'raw': AIMessage(content='', additional_kwargs={'tool_calls': [{'id': 'call_Ao02pnFYXD6GN1yzc0uXPsvF', 'function': {'arguments': '{"answer":"They weigh the same.","justification":"Both a pound of bricks and a pound of feathers weigh one pound. The weight is the same, but the volume or density of the objects may differ."}', 'name': 'AnswerWithJustification'}, 'type': 'function'}]}), # 'parsed': AnswerWithJustification(answer='They weigh the same.', justification='Both a pound of bricks and a pound of feathers weigh one pound. The weight is the same, but the volume or density of the objects may differ.'), # 'parsing_error': None # } Example: Dict schema (include_raw=False): .. code-block:: python from langchain_anthropic import ChatAnthropic schema = { "name": "AnswerWithJustification", "description": "An answer to the user question along with justification for the answer.", "input_schema": { "type": "object", "properties": { "answer": {"type": "string"}, "justification": {"type": "string"}, }, "required": ["answer", "justification"] } } llm = ChatAnthropic(model="claude-3-opus-20240229", temperature=0) structured_llm = llm.with_structured_output(schema) structured_llm.invoke("What weighs more a pound of bricks or a pound of feathers") # -> { # 'answer': 'They weigh the same', # 'justification': 'Both a pound of bricks and a pound of feathers weigh one pound. The weight is the same, but the volume and density of the two substances differ.' # } """ # noqa: E501 llm = self.bind_tools([schema], tool_choice="any") if isinstance(schema, type) and issubclass(schema, BaseModel): output_parser = ToolsOutputParser( first_tool_only=True, pydantic_schemas=[schema] ) else: output_parser = ToolsOutputParser(first_tool_only=True, args_only=True) if include_raw: parser_assign = RunnablePassthrough.assign( parsed=itemgetter("raw") | output_parser, parsing_error=lambda _: None ) parser_none = RunnablePassthrough.assign(parsed=lambda _: None) parser_with_fallback = parser_assign.with_fallbacks( [parser_none], exception_key="parsing_error" ) return RunnableMap(raw=llm) | parser_with_fallback else: return llm | output_parser class AnthropicTool(TypedDict): name: str description: str input_schema: Dict[str, Any] def convert_to_anthropic_tool( tool: Union[Dict[str, Any], Type[BaseModel], Callable, BaseTool], ) -> AnthropicTool: # already in Anthropic tool format if isinstance(tool, dict) and all( k in tool for k in ("name", "description", "input_schema") ): return AnthropicTool(tool) # type: ignore else: formatted = convert_to_openai_tool(tool)["function"] return AnthropicTool( name=formatted["name"], description=formatted["description"], input_schema=formatted["parameters"], ) def _tools_in_params(params: dict) -> bool: return "tools" in params or ( "extra_body" in params and params["extra_body"].get("tools") ) class _AnthropicToolUse(TypedDict): type: Literal["tool_use"] name: str input: dict id: str def _lc_tool_calls_to_anthropic_tool_use_blocks( tool_calls: List[ToolCall], ) -> List[_AnthropicToolUse]: blocks = [] for tool_call in tool_calls: blocks.append( _AnthropicToolUse( type="tool_use", name=tool_call["name"], input=tool_call["args"], id=cast(str, tool_call["id"]), ) ) return blocks @deprecated(since="0.1.0", removal="0.3.0", alternative="ChatAnthropic") class ChatAnthropicMessages(ChatAnthropic): pass