Finance Margin Calculator

{
  "result": {
    "answer": "40% margin",
    "answerLabel": "Selling at 100 (cost 60)",
    "details": [
      {
        "label": "Gross profit per unit",
        "value": "40"
      },
      {
        "label": "Markup",
        "value": "66.67% of cost"
      },
      {
        "label": "Price for a 50% margin",
        "value": "120"
      }
    ],
    "steps": [
      "Profit = 100 − 60 = 40",
      "Margin = 40 ÷ 100 × 100 = 40%",
      "Markup = 40 ÷ 60 × 100 = 66.67%"
    ],
    "value": 40
  },
  "tool": "margin-calculator"
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://agentstoolshub.com/api/v1/finance/margin-calculator?cost=60&price=100'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - 'https://agentstoolshub.com/api/v1/finance/margin-calculator?cost=60&price=100' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.002 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.002" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.002 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fagentstoolshub.com%2Fapi%2Fv1%2Ffinance%2Fmargin-calculator
const res = await pay("https://agentstoolshub.com/api/v1/finance/margin-calculator?cost=60&price=100");
console.log(res.status, await res.text());

# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.002 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.002"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://agentstoolshub.com/api/v1/finance/margin-calculator?cost=60&price=100")
    print(res.status_code, res.text)