base.py — langchain Source File

Source Code

"""Implement an LLM driven browser."""

from __future__ import annotations

import warnings
from typing import Any

from langchain_core._api import deprecated
from langchain_core.callbacks import CallbackManagerForChainRun
from langchain_core.language_models import BaseLanguageModel
from langchain_core.output_parsers import StrOutputParser
from langchain_core.runnables import Runnable
from pydantic import ConfigDict, model_validator

from langchain_classic.chains.base import Chain
from langchain_classic.chains.natbot.prompt import PROMPT


@deprecated(
    since="0.2.13",
    message=(
        "Importing NatBotChain from langchain is deprecated and will be removed in "
        "langchain 1.0. Please import from langchain_community instead: "
        "from langchain_community.chains.natbot import NatBotChain. "
        "You may need to pip install -U langchain-community."
    ),
    removal="1.0",
)
class NatBotChain(Chain):
    """Implement an LLM driven browser.

    **Security Note**: This toolkit provides code to control a web-browser.

        The web-browser can be used to navigate to:

        - Any URL (including any internal network URLs)
        - And local files

        Exercise care if exposing this chain to end-users. Control who is able to
        access and use this chain, and isolate the network access of the server
        that hosts this chain.

        See https://docs.langchain.com/oss/python/security-policy for more information.

    Example:
        ```python
        from langchain_classic.chains import NatBotChain

        natbot = NatBotChain.from_default("Buy me a new hat.")
        ```
    """

    llm_chain: Runnable
    objective: str
    """Objective that NatBot is tasked with completing."""
    llm: BaseLanguageModel | None = None
    """[Deprecated] LLM wrapper to use."""
    input_url_key: str = "url"
    input_browser_content_key: str = "browser_content"
    previous_command: str = ""
// ... (99 more lines)