dify/api/core/chain/tool_chain.py
John Wang 3241e4015b
feat: upgrade langchain (#430)
Co-authored-by: jyong <718720800@qq.com>
2023-06-25 16:49:14 +08:00

52 lines
1.4 KiB
Python

from typing import List, Dict, Optional, Any
from langchain.callbacks.manager import CallbackManagerForChainRun, AsyncCallbackManagerForChainRun
from langchain.chains.base import Chain
from langchain.tools import BaseTool
class ToolChain(Chain):
input_key: str = "input" #: :meta private:
output_key: str = "output" #: :meta private:
tool: BaseTool
@property
def _chain_type(self) -> str:
return "tool_chain"
@property
def input_keys(self) -> List[str]:
"""Expect input key.
:meta private:
"""
return [self.input_key]
@property
def output_keys(self) -> List[str]:
"""Return output key.
:meta private:
"""
return [self.output_key]
def _call(
self,
inputs: Dict[str, Any],
run_manager: Optional[CallbackManagerForChainRun] = None,
) -> Dict[str, Any]:
input = inputs[self.input_key]
output = self.tool.run(input, self.verbose)
return {self.output_key: output}
async def _acall(
self,
inputs: Dict[str, Any],
run_manager: Optional[AsyncCallbackManagerForChainRun] = None,
) -> Dict[str, Any]:
"""Run the logic of this chain and return the output."""
input = inputs[self.input_key]
output = await self.tool.arun(input, self.verbose)
return {self.output_key: output}