Currency Exchange Batch

{
  "amount": 100,
  "findings": [],
  "from": "USD",
  "rates": [
    {
      "converted_amount": 87.07,
      "rate": 0.8707,
      "rate_date": "2026-07-31",
      "source": "frankfurter",
      "to": "EUR"
    },
    {
      "converted_amount": 375,
      "rate": 3.75,
      "rate_date": "2026-08-01",
      "source": "currency-api",
      "to": "SAR"
    },
    {
      "converted_amount": 0.0016014961,
      "rate": 0.000016014961,
      "rate_date": "2026-08-01",
      "source": "coinbase",
      "to": "BTC"
    }
  ],
  "stale": false,
  "unavailable": []
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://netintel.dev/currency-exchange/batch?amount=100&from=USD&to=EUR%2CSAR%2CBTC'

# 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://netintel.dev/currency-exchange/batch?amount=100&from=USD&to=EUR%2CSAR%2CBTC' \
  | 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 $0.02 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.02" });
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 $0.02 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fnetintel.dev%2Fcurrency-exchange%2Fbatch
const res = await pay("https://netintel.dev/currency-exchange/batch?amount=100&from=USD&to=EUR%2CSAR%2CBTC");
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 $0.02 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.02"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://netintel.dev/currency-exchange/batch?amount=100&from=USD&to=EUR%2CSAR%2CBTC")
    print(res.status_code, res.text)