Source code for langchain_community.callbacks.human

from typing import Any, Awaitable, Callable, Dict, Optional
from uuid import UUID

from langchain_core.callbacks import AsyncCallbackHandler, BaseCallbackHandler


def _default_approve(_input: str) -> bool:
    msg = (
        "Do you approve of the following input? "
        "Anything except 'Y'/'Yes' (case-insensitive) will be treated as a no."
    )
    msg += "\n\n" + _input + "\n"
    resp = input(msg)
    return resp.lower() in ("yes", "y")


async def _adefault_approve(_input: str) -> bool:
    msg = (
        "Do you approve of the following input? "
        "Anything except 'Y'/'Yes' (case-insensitive) will be treated as a no."
    )
    msg += "\n\n" + _input + "\n"
    resp = input(msg)
    return resp.lower() in ("yes", "y")


def _default_true(_: Dict[str, Any]) -> bool:
    return True


[docs]class HumanRejectedException(Exception): """Exception to raise when a person manually review and rejects a value."""
[docs]class HumanApprovalCallbackHandler(BaseCallbackHandler): """Callback for manually validating values.""" raise_error: bool = True
[docs] def __init__( self, approve: Callable[[Any], bool] = _default_approve, should_check: Callable[[Dict[str, Any]], bool] = _default_true, ): self._approve = approve self._should_check = should_check
[docs] def on_tool_start( self, serialized: Dict[str, Any], input_str: str, *, run_id: UUID, parent_run_id: Optional[UUID] = None, **kwargs: Any, ) -> Any: if self._should_check(serialized) and not self._approve(input_str): raise HumanRejectedException( f"Inputs {input_str} to tool {serialized} were rejected." )
[docs]class AsyncHumanApprovalCallbackHandler(AsyncCallbackHandler): """Asynchronous callback for manually validating values.""" raise_error: bool = True
[docs] def __init__( self, approve: Callable[[Any], Awaitable[bool]] = _adefault_approve, should_check: Callable[[Dict[str, Any]], bool] = _default_true, ): self._approve = approve self._should_check = should_check
[docs] async def on_tool_start( self, serialized: Dict[str, Any], input_str: str, *, run_id: UUID, parent_run_id: Optional[UUID] = None, **kwargs: Any, ) -> Any: if self._should_check(serialized) and not await self._approve(input_str): raise HumanRejectedException( f"Inputs {input_str} to tool {serialized} were rejected." )