ToolVet
78trust / 100

Fx

by offercheck in Markets & finance

x402 APIPassing, checked 1 h ago

Convert between 30 major currencies (USD, EUR, GBP, JPY, CHF, CNY, INR, ILS, AUD, CAD, ...) using the European Central Bank's daily reference rates: rate and converted amount for one or many target currencies, optional historical date back to 1999. Returns the ECB rate date and source. $0.002 per call.

GET
https://offercheck.offercheck.workers.dev/v1/fx
Price
$0.002
per call in USDC
Uptime
100%
last 30 days
Response time
317 ms
479 ms slowest 5%
Last check
Passed
1 h ago, next any minute now

Run a free test callHow to call it

Reliability

All checks passedSome failedAll failedNot checked

Status and outage history · Atom feed

How to call it

GET https://offercheck.offercheck.workers.dev/v1/fx

Each call costs $0.002 in USDC on Base, paid with the request over x402.

Run a free test callOne unpaid request, the way an agent sends it. You see the payment challenge it gets back. Nothing is charged.

Example request

From the listing.

GET https://offercheck.offercheck.workers.dev/v1/fx?amount=100&from=USD&to=EUR%2CGBP

Parameters

ParameterTypeRequiredDescription
amountstringNoAmount in the base currency to convert, as a decimal number string, e.g. "100" (default 1). Query parameters are strings, so the Coinbase Bazaar validator rejects a numeric type here. Default: "1".
datestringNoOptional historical date YYYY-MM-DD (ECB business days from 1999-01-04); omit for the latest rates
fromstringNoBase currency, ISO 4217 code (default USD) Default: "USD".
tostringNoTarget currency or comma-separated list (default EUR); any of the 30 ECB currencies Default: "EUR".

Example response

The provider's example. We can't check it without paying.

{
  "amount": 100,
  "date": "2026-09-25",
  "fetched_at": "2026-09-25T20:00:00.000Z",
  "from": "USD",
  "ms": 95,
  "rates": {
    "EUR": {
      "converted": 87.696,
      "rate": 0.87696
    },
    "GBP": {
      "converted": 75.458,
      "rate": 0.75458
    }
  },
  "source": "European Central Bank euro foreign exchange reference rates (published once per business day ~16:00 CET) via frankfurter.dev; non-EUR pairs are cross rates through EUR",
  "warnings": []
}

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.002.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://offercheck.offercheck.workers.dev/v1/fx?amount=100&from=USD&to=EUR%2CGBP'

# 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://offercheck.offercheck.workers.dev/v1/fx?amount=100&from=USD&to=EUR%2CGBP' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode
JavaScript: pay and call
// 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%2Foffercheck.offercheck.workers.dev%2Fv1%2Ffx
const res = await pay("https://offercheck.offercheck.workers.dev/v1/fx?amount=100&from=USD&to=EUR%2CGBP");
console.log(res.status, await res.text());
Python: pay and call
# 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://offercheck.offercheck.workers.dev/v1/fx?amount=100&from=USD&to=EUR%2CGBP")
    print(res.status_code, res.text)

Security scan

No findings

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Recent checks

WhenResultHTTPTimePrice
1 h agoPassed402136 ms$0.002
5 h agoPassed402270 ms$0.002
10 h agoPassed402290 ms$0.002
14 h agoPassed402326 ms$0.002
18 h agoPassed402144 ms$0.002
Show 10 older checks
22 h agoPassed402426 ms$0.002
26 h agoPassed402319 ms$0.002
30 h agoPassed402413 ms$0.002
34 h agoPassed402325 ms$0.002
38 h agoPassed40241 ms$0.002
41 h agoPassed402490 ms$0.002
46 h agoPassed402328 ms$0.002
2 days agoPassed402194 ms$0.002
2 days agoPassed402317 ms$0.002
2 days agoPassed402280 ms$0.002