78trust / 100

Ref Currency

by Duo Data Utilities in Markets & finance

x402 APIPassing, checked 3 h ago

Look up a currency by its ISO 4217 alphabetic or numeric code: the official English name, minor-unit exponent, fund flag, the smallest cash denomination where it differs from the minor unit, the territories that use it, and historic codes on request. Returns the correct rounding increment for cash amounts, which is what a caller needs to render or settle a price. This route returns currency facts only and never an exchange rate.

GET
https://api.duoleads.com/v1/ref/currency
Price
$0.05
per call in USDC
Uptime
100%
last 30 days
Response time
144 ms
851 ms slowest 5%
Last check
Passed
3 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://api.duoleads.com/v1/ref/currency

Each call costs $0.05 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://api.duoleads.com/v1/ref/currency?code=EUR&include=territories

Parameters

ParameterTypeRequiredDescription
codestringNoISO 4217 alpha-3 or 3-digit numeric code.
countrystringNoISO 3166-1 alpha-2; returns the currencies in use there.
includestringNoComma-separated: territories, historic. Default none.

Example response

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

Example response, 61 lines
{
  "data": {
    "cash_minor_units": 2,
    "cash_rounding": null,
    "code": "EUR",
    "found": true,
    "is_fund": false,
    "minor_units": 2,
    "name": "Euro",
    "numeric": "978",
    "status": "current",
    "territories": [
      "AD",
      "AT",
      "AX",
      "BE",
      "BG",
      "BL",
      "CY",
      "DE",
      "EE",
      "ES",
      "FI",
      "FR",
      "GF",
      "GP",
      "GR",
      "HR",
      "IE",
      "IT",
      "LT",
      "LU"
    ]
  },
  "meta": {
    "computed_at": "2026-09-28T12:00:00.000Z",
    "deterministic": true,
    "disclaimer": "Factual output of a deterministic computation over public data. Provided as is, with no warranty of accuracy, completeness or availability. Not investment, financial, legal, tax, medical or any other professional advice, and not a recommendation. Verify before relying on it. Terms: https://api.duoleads.com/terms",
    "price_usd": "0.05",
    "request_id": "01K6B7Q4ZC8H3F2M9WXR5TYN0D",
    "sources": [
      {
        "attribution": "ISO 4217 currency and funds code lists, published by SIX Group as secretariat of the ISO 4217 Maintenance Agency (public data)",
        "id": "iso-4217",
        "licence": "Public data (owner decision 2026-09-29)",
        "published": "2026-09-17",
        "version": "SIX list one 2026-09-17, list three 2026-01-01"
      },
      {
        "attribution": "Unicode CLDR, © Unicode, Inc.",
        "id": "cldr-currency-data",
        "licence": "Unicode-3.0",
        "published": "2026-09-28",
        "version": "48.2.2"
      }
    ]
  },
  "ok": true,
  "route": "/v1/ref/currency",
  "version": "1.0.0"
}

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.05.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://api.duoleads.com/v1/ref/currency?code=EUR&include=territories'

# 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://api.duoleads.com/v1/ref/currency?code=EUR&include=territories' \
  | 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 $0.05 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.05" });
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 $0.05 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fapi.duoleads.com%2Fv1%2Fref%2Fcurrency
const res = await pay("https://api.duoleads.com/v1/ref/currency?code=EUR&include=territories");
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 $0.05 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.05"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://api.duoleads.com/v1/ref/currency?code=EUR&include=territories")
    print(res.status_code, res.text)

Security scan

No findings

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Recent checks

WhenResultHTTPTimePrice
3 h agoPassed402907 ms$0.05
7 h agoPassed40267 ms$0.05
11 h agoPassed402143 ms$0.05
15 h agoPassed402616 ms$0.05
20 h agoPassed402242 ms$0.05
Show 10 older checks
24 h agoPassed402538 ms$0.05
28 h agoPassed40249 ms$0.05
32 h agoPassed402127 ms$0.05
36 h agoPassed402114 ms$0.05
39 h agoPassed402158 ms$0.05
43 h agoPassed402127 ms$0.05
47 h agoPassed402183 ms$0.05
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2 days agoPassed40242 ms$0.05