Files
crewAI/src/crewai/tools/tool_usage.py
2024-02-10 10:36:34 -08:00

113 lines
4.2 KiB
Python

from typing import Any, List
from langchain.output_parsers import PydanticOutputParser
from langchain.prompts import PromptTemplate
from langchain_core.tools import BaseTool
from crewai.agents.tools_handler import ToolsHandler
from crewai.telemtry import Telemetry
from crewai.tools.tool_calling import ToolCalling
from crewai.utilities import I18N, Printer
class ToolUsage:
"""
Class that represents the usage of a tool by an agent.
Attributes:
tools_handler: Tools handler that will manage the tool usage.
tools: List of tools available for the agent.
llm: Language model to be used for the tool usage.
"""
def __init__(
self, tools_handler: ToolsHandler, tools: List[BaseTool], llm: Any
) -> None:
self._i18n: I18N = I18N()
self._printer: Printer = Printer()
self._telemetry: Telemetry = Telemetry()
self._run_attempts: int = 1
self._max_parsing_attempts: int = 3
self.tools_handler = tools_handler
self.tools = tools
self.llm = llm
def use(self, tool_string: str):
calling = self._tool_calling(tool_string)
tool = self._select_tool(calling.function_name)
return self._use(tool=tool, calling=calling)
def _use(self, tool: BaseTool, calling: ToolCalling) -> None:
if self._check_tool_repeated_usage(calling=calling):
result = self._i18n.errors("task_repeated_usage").format(
tool=calling.function_name, tool_input=calling.arguments
)
else:
self.tools_handler.on_tool_start(calling=calling)
result = self.tools_handler.cache.read(
tool=calling.function_name, input=calling.arguments
)
if not result:
result = tool._run(**calling.arguments)
self.tools_handler.on_tool_end(calling=calling, output=result)
self._printer.print(content=f"\n\n{result}\n", color="yellow")
self._telemetry.tool_usage(
llm=self.llm, tool_name=tool.name, attempts=self._run_attempts
)
return result
def _check_tool_repeated_usage(self, calling: ToolCalling) -> None:
if last_tool_usage := self.tools_handler.last_used_tool:
return calling == last_tool_usage
def _select_tool(self, tool_name: str) -> BaseTool:
for tool in self.tools:
if tool.name == tool_name:
return tool
raise Exception(f"Tool '{tool_name}' not found.")
def _render(self) -> str:
"""Render the tool name and description in plain text."""
descriptions = []
for tool in self.tools:
args = {
k: {k2: v2 for k2, v2 in v.items() if k2 in ["description", "type"]}
for k, v in tool.args.items()
}
descriptions.append(
"\n".join(
[
f"Funtion Name: {tool.name}",
f"Funtion attributes: {args}",
f"Description: {tool.description}",
]
)
)
return "\n--\n".join(descriptions)
def _tool_calling(self, tool_string: str) -> ToolCalling:
try:
parser = PydanticOutputParser(pydantic_object=ToolCalling)
prompt = PromptTemplate(
template="Return a valid schema for the one tool you must use with its arguments and values.\n\nTools available:\n\n{available_tools}\n\nUse this text to inform a valid ouput schema:\n{tool_string}\n\n{format_instructions}\n```",
input_variables=["tool_string"],
partial_variables={
"available_tools": self._render(),
"format_instructions": parser.get_format_instructions(),
},
)
chain = prompt | self.llm | parser
calling = chain.invoke({"tool_string": tool_string})
except Exception as e:
self._run_attempts += 1
if self._run_attempts > self._max_parsing_attempts:
self._telemetry.tool_usage_error(llm=self.llm)
raise e
return self._tool_calling(tool_string)
return calling