LCToolComponent without input

[kamushekp]

@dosu-bot provide an example of custom tool that based on LCToolComponent and have no inputs (for example, just returns current temperature)

[dosubot[bot]]

To create a custom tool based on LCToolComponent that returns the current temperature without any inputs, you can subclass LCToolComponent and implement the build_tool and run_model methods. Here's an example:

from langflow.base.langchain_utilities.model import LCToolComponent
from langflow.field_typing import Tool
from langflow.schema import Data
import requests

class TemperatureComponent(LCToolComponent):
    name: str = "TemperatureComponent"
    description: str = "Returns the current temperature."

    def build_tool(self) -> Tool:
        return Tool(name="TemperatureTool", description="Returns current temperature")

    def run_model(self) -> Data:
        # Example API call to get the current temperature
        response = requests.get("https://api.weatherapi.com/v1/current.json?key=YOUR_API_KEY&q=London")
        temperature = response.json().get("current", {}).get("temp_c", "N/A")
        return Data(data=f"Current temperature: {temperature}°C")

Replace "YOUR_API_KEY" with your actual API key and adjust the API endpoint as needed. This component fetches the current temperature and returns it as data.

To continue talking to Dosu, mention @dosu.

[kamushekp]

@dosu, init of Tool seems to be obsolete. How to implement what i want using from_function classmethod?

[dosubot[bot]]

To implement a custom tool using the from_function class method, you can define a function that performs the desired action and then use StructuredTool.from_function to create the tool. Here's how you can modify the previous example to use from_function:

from langflow.base.langchain_utilities.model import StructuredTool
from langflow.schema import Data
import requests
from pydantic import BaseModel

# Define a Pydantic model for the schema if needed
class TemperatureSchema(BaseModel):
    pass  # No inputs required

# Define the function to get the current temperature
def get_current_temperature() -> str:
    response = requests.get("https://api.weatherapi.com/v1/current.json?key=YOUR_API_KEY&q=London")
    temperature = response.json().get("current", {}).get("temp_c", "N/A")
    return f"Current temperature: {temperature}°C"

# Create the tool using from_function
TemperatureTool = StructuredTool.from_function(
    func=get_current_temperature,
    args_schema=TemperatureSchema,
    name="TemperatureTool",
    description="Returns current temperature",
    return_direct=True
)

Replace "YOUR_API_KEY" with your actual API key. This setup uses from_function to create a tool that returns the current temperature without requiring any inputs.

To continue talking to Dosu, mention @dosu.