crewAI/src/crewai_tools/tools/base_tool.py

from typing import Any, Callable

from pydantic import BaseModel as PydanticBaseModel

from crewai.tools.base_tool import BaseTool
from crewai.tools.structured_tool import CrewStructuredTool


class Tool(BaseTool):
    func: Callable
    """The function that will be executed when the tool is called."""

    def _run(self, *args: Any, **kwargs: Any) -> Any:
        return self.func(*args, **kwargs)


def to_langchain(
    tools: list[BaseTool | CrewStructuredTool],
) -> list[CrewStructuredTool]:
    return [t.to_structured_tool() if isinstance(t, BaseTool) else t for t in tools]


def tool(*args):
    """
    Decorator to create a tool from a function.
    """

    def _make_with_name(tool_name: str) -> Callable:
        def _make_tool(f: Callable) -> BaseTool:
            if f.__doc__ is None:
                raise ValueError("Function must have a docstring")
            if f.__annotations__ is None:
                raise ValueError("Function must have type annotations")

            class_name = "".join(tool_name.split()).title()
            args_schema = type(
                class_name,
                (PydanticBaseModel,),
                {
                    "__annotations__": {
                        k: v for k, v in f.__annotations__.items() if k != "return"
                    },
                },
            )

            return Tool(
                name=tool_name,
                description=f.__doc__,
                func=f,
                args_schema=args_schema,
            )

        return _make_tool

    if len(args) == 1 and callable(args[0]):
        return _make_with_name(args[0].__name__)(args[0])
    if len(args) == 1 and isinstance(args[0], str):
        return _make_with_name(args[0])
    raise ValueError("Invalid arguments")