A CrewAI agent that buys the data it needs.

# tools/convert_currency.py
# pip install crewai "x402[requests,evm]"

import os

from crewai.tools import tool
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients.requests import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# The x402 client only signs payments. x402_requests turns it into a plain
# requests.Session that answers the 402 and retries the call. Build it once at
# import time; every tool below reuses it.
account = Account.from_key(os.environ["WALLET_PRIVATE_KEY"])
payments = x402ClientSync()
register_exact_evm_client(payments, EthAccountSigner(account))
session = x402_requests(payments)


@tool("Convert currency")
def convert_currency(from_code: str, to_code: str, amount: float) -> dict:
    """Convert an amount between two currencies using live FX rates.

    Paid per call in USDC on Base. No API key required.
    """
    response = session.get(
        "https://gateway.apiosk.com/v1/fx/convert",
        params={"from": from_code, "to": to_code, "amount": amount},
    )
    response.raise_for_status()
    return response.json()

# tools/verify_email.py
# The subclass form. Use it when you want to name and describe the arguments
# yourself instead of letting CrewAI read them off the signature.

from crewai.tools import BaseTool
from pydantic import BaseModel, Field

from tools.convert_currency import session  # one paying session for every tool


class VerifyEmailInput(BaseModel):
    email: str = Field(description="Address to check, e.g. ada@example.com")


class VerifyEmailTool(BaseTool):
    name: str = "Verify email"
    description: str = (
        "Check whether an email address is deliverable. "
        "Returns the verdict and the reason for it."
    )
    args_schema: type[BaseModel] = VerifyEmailInput

    def _run(self, email: str) -> dict:
        response = session.get(
            "https://gateway.apiosk.com/v1/email/verify",
            params={"email": email},
        )
        response.raise_for_status()
        return response.json()

# crew.py
# Run with: python crew.py

from crewai import Agent, Crew, Task

from tools.convert_currency import convert_currency
from tools.verify_email import VerifyEmailTool

# @tool returns a Tool, which is a BaseTool, so both forms go in the same list.
analyst = Agent(
    role="Operations analyst",
    goal="Answer questions that need live data",
    backstory="You check numbers with a source before you report them.",
    tools=[convert_currency, VerifyEmailTool()],
    verbose=True,
)

task = Task(
    description="What is 250 EUR in USD right now?",
    expected_output="The converted amount and the rate used.",
    agent=analyst,
)

result = Crew(agents=[analyst], tasks=[task]).kickoff()
print(result.raw)  # kickoff returns a CrewOutput; .raw is the string answer