159 lines
5.1 KiB
Python
159 lines
5.1 KiB
Python
"""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 = ""
|
|
output_key: str = "command"
|
|
|
|
model_config = ConfigDict(
|
|
arbitrary_types_allowed=True,
|
|
extra="forbid",
|
|
)
|
|
|
|
@model_validator(mode="before")
|
|
@classmethod
|
|
def _raise_deprecation(cls, values: dict) -> Any:
|
|
if "llm" in values:
|
|
warnings.warn(
|
|
"Directly instantiating an NatBotChain with an llm is deprecated. "
|
|
"Please instantiate with llm_chain argument or using the from_llm "
|
|
"class method.",
|
|
stacklevel=5,
|
|
)
|
|
if "llm_chain" not in values and values["llm"] is not None:
|
|
values["llm_chain"] = PROMPT | values["llm"] | StrOutputParser()
|
|
return values
|
|
|
|
@classmethod
|
|
def from_default(cls, objective: str, **kwargs: Any) -> NatBotChain:
|
|
"""Load with default LLMChain."""
|
|
msg = (
|
|
"This method is no longer implemented. Please use from_llm."
|
|
"model = OpenAI(temperature=0.5, best_of=10, n=3, max_tokens=50)"
|
|
"For example, NatBotChain.from_llm(model, objective)"
|
|
)
|
|
raise NotImplementedError(msg)
|
|
|
|
@classmethod
|
|
def from_llm(
|
|
cls,
|
|
llm: BaseLanguageModel,
|
|
objective: str,
|
|
**kwargs: Any,
|
|
) -> NatBotChain:
|
|
"""Load from LLM."""
|
|
llm_chain = PROMPT | llm | StrOutputParser()
|
|
return cls(llm_chain=llm_chain, objective=objective, **kwargs)
|
|
|
|
@property
|
|
def input_keys(self) -> list[str]:
|
|
"""Expect url and browser content."""
|
|
return [self.input_url_key, self.input_browser_content_key]
|
|
|
|
@property
|
|
def output_keys(self) -> list[str]:
|
|
"""Return command."""
|
|
return [self.output_key]
|
|
|
|
def _call(
|
|
self,
|
|
inputs: dict[str, str],
|
|
run_manager: CallbackManagerForChainRun | None = None,
|
|
) -> dict[str, str]:
|
|
_run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager()
|
|
url = inputs[self.input_url_key]
|
|
browser_content = inputs[self.input_browser_content_key]
|
|
llm_cmd = self.llm_chain.invoke(
|
|
{
|
|
"objective": self.objective,
|
|
"url": url[:100],
|
|
"previous_command": self.previous_command,
|
|
"browser_content": browser_content[:4500],
|
|
},
|
|
config={"callbacks": _run_manager.get_child()},
|
|
)
|
|
llm_cmd = llm_cmd.strip()
|
|
self.previous_command = llm_cmd
|
|
return {self.output_key: llm_cmd}
|
|
|
|
def execute(self, url: str, browser_content: str) -> str:
|
|
"""Figure out next browser command to run.
|
|
|
|
Args:
|
|
url: URL of the site currently on.
|
|
browser_content: Content of the page as currently displayed by the browser.
|
|
|
|
Returns:
|
|
Next browser command to run.
|
|
|
|
Example:
|
|
```python
|
|
browser_content = "...."
|
|
llm_command = natbot.run("www.google.com", browser_content)
|
|
```
|
|
"""
|
|
_inputs = {
|
|
self.input_url_key: url,
|
|
self.input_browser_content_key: browser_content,
|
|
}
|
|
return self(_inputs)[self.output_key]
|
|
|
|
@property
|
|
def _chain_type(self) -> str:
|
|
return "nat_bot_chain"
|