Source code for langchain_community.chat_models.ollama

import json
from typing import Any, AsyncIterator, Dict, Iterator, List, Optional, Union, cast

from langchain_core._api import deprecated
from langchain_core.callbacks import (
    AsyncCallbackManagerForLLMRun,
    CallbackManagerForLLMRun,
)
from langchain_core.language_models.chat_models import BaseChatModel
from langchain_core.messages import (
    AIMessage,
    AIMessageChunk,
    BaseMessage,
    ChatMessage,
    HumanMessage,
    SystemMessage,
)
from langchain_core.outputs import ChatGeneration, ChatGenerationChunk, ChatResult

from langchain_community.llms.ollama import OllamaEndpointNotFoundError, _OllamaCommon


@deprecated("0.0.3", alternative="_chat_stream_response_to_chat_generation_chunk")
def _stream_response_to_chat_generation_chunk(
    stream_response: str,
) -> ChatGenerationChunk:
    """Convert a stream response to a generation chunk."""
    parsed_response = json.loads(stream_response)
    generation_info = parsed_response if parsed_response.get("done") is True else None
    return ChatGenerationChunk(
        message=AIMessageChunk(content=parsed_response.get("response", "")),
        generation_info=generation_info,
    )


def _chat_stream_response_to_chat_generation_chunk(
    stream_response: str,
) -> ChatGenerationChunk:
    """Convert a stream response to a generation chunk."""
    parsed_response = json.loads(stream_response)
    generation_info = parsed_response if parsed_response.get("done") is True else None
    return ChatGenerationChunk(
        message=AIMessageChunk(
            content=parsed_response.get("message", {}).get("content", "")
        ),
        generation_info=generation_info,
    )


[docs]class ChatOllama(BaseChatModel, _OllamaCommon): """Ollama locally runs large language models. To use, follow the instructions at https://ollama.ai/. Example: .. code-block:: python from langchain_community.chat_models import ChatOllama ollama = ChatOllama(model="llama2") """ @property def _llm_type(self) -> str: """Return type of chat model.""" return "ollama-chat"
[docs] @classmethod def is_lc_serializable(cls) -> bool: """Return whether this model can be serialized by Langchain.""" return False
@deprecated("0.0.3", alternative="_convert_messages_to_ollama_messages") def _format_message_as_text(self, message: BaseMessage) -> str: if isinstance(message, ChatMessage): message_text = f"\n\n{message.role.capitalize()}: {message.content}" elif isinstance(message, HumanMessage): if isinstance(message.content, List): first_content = cast(List[Dict], message.content)[0] content_type = first_content.get("type") if content_type == "text": message_text = f"[INST] {first_content['text']} [/INST]" elif content_type == "image_url": message_text = first_content["image_url"]["url"] else: message_text = f"[INST] {message.content} [/INST]" elif isinstance(message, AIMessage): message_text = f"{message.content}" elif isinstance(message, SystemMessage): message_text = f"<<SYS>> {message.content} <</SYS>>" else: raise ValueError(f"Got unknown type {message}") return message_text def _format_messages_as_text(self, messages: List[BaseMessage]) -> str: return "\n".join( [self._format_message_as_text(message) for message in messages] ) def _convert_messages_to_ollama_messages( self, messages: List[BaseMessage] ) -> List[Dict[str, Union[str, List[str]]]]: ollama_messages: List = [] for message in messages: role = "" if isinstance(message, HumanMessage): role = "user" elif isinstance(message, AIMessage): role = "assistant" elif isinstance(message, SystemMessage): role = "system" else: raise ValueError("Received unsupported message type for Ollama.") content = "" images = [] if isinstance(message.content, str): content = message.content else: for content_part in cast(List[Dict], message.content): if content_part.get("type") == "text": content += f"\n{content_part['text']}" elif content_part.get("type") == "image_url": if isinstance(content_part.get("image_url"), str): image_url_components = content_part["image_url"].split(",") # Support data:image/jpeg;base64,<image> format # and base64 strings if len(image_url_components) > 1: images.append(image_url_components[1]) else: images.append(image_url_components[0]) else: raise ValueError( "Only string image_url " "content parts are supported." ) else: raise ValueError( "Unsupported message content type. " "Must either have type 'text' or type 'image_url' " "with a string 'image_url' field." ) ollama_messages.append( { "role": role, "content": content, "images": images, } ) return ollama_messages def _create_chat_stream( self, messages: List[BaseMessage], stop: Optional[List[str]] = None, **kwargs: Any, ) -> Iterator[str]: payload = { "messages": self._convert_messages_to_ollama_messages(messages), } yield from self._create_stream( payload=payload, stop=stop, api_url=f"{self.base_url}/api/chat", **kwargs ) async def _acreate_chat_stream( self, messages: List[BaseMessage], stop: Optional[List[str]] = None, **kwargs: Any, ) -> AsyncIterator[str]: payload = { "messages": self._convert_messages_to_ollama_messages(messages), } async for stream_resp in self._acreate_stream( payload=payload, stop=stop, api_url=f"{self.base_url}/api/chat", **kwargs ): yield stream_resp def _chat_stream_with_aggregation( self, messages: List[BaseMessage], stop: Optional[List[str]] = None, run_manager: Optional[CallbackManagerForLLMRun] = None, verbose: bool = False, **kwargs: Any, ) -> ChatGenerationChunk: final_chunk: Optional[ChatGenerationChunk] = None for stream_resp in self._create_chat_stream(messages, stop, **kwargs): if stream_resp: chunk = _chat_stream_response_to_chat_generation_chunk(stream_resp) if final_chunk is None: final_chunk = chunk else: final_chunk += chunk if run_manager: run_manager.on_llm_new_token( chunk.text, chunk=chunk, verbose=verbose, ) if final_chunk is None: raise ValueError("No data received from Ollama stream.") return final_chunk async def _achat_stream_with_aggregation( self, messages: List[BaseMessage], stop: Optional[List[str]] = None, run_manager: Optional[AsyncCallbackManagerForLLMRun] = None, verbose: bool = False, **kwargs: Any, ) -> ChatGenerationChunk: final_chunk: Optional[ChatGenerationChunk] = None async for stream_resp in self._acreate_chat_stream(messages, stop, **kwargs): if stream_resp: chunk = _chat_stream_response_to_chat_generation_chunk(stream_resp) if final_chunk is None: final_chunk = chunk else: final_chunk += chunk if run_manager: await run_manager.on_llm_new_token( chunk.text, chunk=chunk, verbose=verbose, ) if final_chunk is None: raise ValueError("No data received from Ollama stream.") return final_chunk def _generate( self, messages: List[BaseMessage], stop: Optional[List[str]] = None, run_manager: Optional[CallbackManagerForLLMRun] = None, **kwargs: Any, ) -> ChatResult: """Call out to Ollama's generate endpoint. Args: messages: The list of base messages to pass into the model. stop: Optional list of stop words to use when generating. Returns: Chat generations from the model Example: .. code-block:: python response = ollama([ HumanMessage(content="Tell me about the history of AI") ]) """ final_chunk = self._chat_stream_with_aggregation( messages, stop=stop, run_manager=run_manager, verbose=self.verbose, **kwargs, ) chat_generation = ChatGeneration( message=AIMessage(content=final_chunk.text), generation_info=final_chunk.generation_info, ) return ChatResult(generations=[chat_generation]) async def _agenerate( self, messages: List[BaseMessage], stop: Optional[List[str]] = None, run_manager: Optional[AsyncCallbackManagerForLLMRun] = None, **kwargs: Any, ) -> ChatResult: """Call out to Ollama's generate endpoint. Args: messages: The list of base messages to pass into the model. stop: Optional list of stop words to use when generating. Returns: Chat generations from the model Example: .. code-block:: python response = ollama([ HumanMessage(content="Tell me about the history of AI") ]) """ final_chunk = await self._achat_stream_with_aggregation( messages, stop=stop, run_manager=run_manager, verbose=self.verbose, **kwargs, ) chat_generation = ChatGeneration( message=AIMessage(content=final_chunk.text), generation_info=final_chunk.generation_info, ) return ChatResult(generations=[chat_generation]) def _stream( self, messages: List[BaseMessage], stop: Optional[List[str]] = None, run_manager: Optional[CallbackManagerForLLMRun] = None, **kwargs: Any, ) -> Iterator[ChatGenerationChunk]: try: for stream_resp in self._create_chat_stream(messages, stop, **kwargs): if stream_resp: chunk = _chat_stream_response_to_chat_generation_chunk(stream_resp) if run_manager: run_manager.on_llm_new_token( chunk.text, chunk=chunk, verbose=self.verbose, ) yield chunk except OllamaEndpointNotFoundError: yield from self._legacy_stream(messages, stop, **kwargs) async def _astream( self, messages: List[BaseMessage], stop: Optional[List[str]] = None, run_manager: Optional[AsyncCallbackManagerForLLMRun] = None, **kwargs: Any, ) -> AsyncIterator[ChatGenerationChunk]: async for stream_resp in self._acreate_chat_stream(messages, stop, **kwargs): if stream_resp: chunk = _chat_stream_response_to_chat_generation_chunk(stream_resp) if run_manager: await run_manager.on_llm_new_token( chunk.text, chunk=chunk, verbose=self.verbose, ) yield chunk @deprecated("0.0.3", alternative="_stream") def _legacy_stream( self, messages: List[BaseMessage], stop: Optional[List[str]] = None, run_manager: Optional[CallbackManagerForLLMRun] = None, **kwargs: Any, ) -> Iterator[ChatGenerationChunk]: prompt = self._format_messages_as_text(messages) for stream_resp in self._create_generate_stream(prompt, stop, **kwargs): if stream_resp: chunk = _stream_response_to_chat_generation_chunk(stream_resp) if run_manager: run_manager.on_llm_new_token( chunk.text, chunk=chunk, verbose=self.verbose, ) yield chunk