devdrops-fx-rates— agent skill

When to use this skill

• User wants the current exchange rate between two currencies
• Agent is converting a monetary amount for display, calculation, or payment
• User asks "what's the USD/GBP rate?", "convert 500 EUR to JPY", or "what was the EUR/USD rate last Tuesday?"
• Agent needs to normalise multi-currency data to a common base for comparison

How it works

The endpoint proxies the ECB's daily reference rates via Frankfurter — an open-source, free, no-key API backed by official ECB data. Rates are updated daily at ~16:00 CET on business days. The latest endpoint returns today's rates; convert applies the rate to an amount; historical queries rates for a specific past date. This endpoint costs $0.001 per query and is in the free tier (5 queries/day/IP before payment).

Endpoints

Parameters

Supported currencies

EUR, USD, GBP, JPY, CHF, AUD, CAD, CNY, HKD, NZD, SEK, NOK, DKK, SGD, INR, MXN, BRL, ZAR, RUB, TRY, PLN, CZK, HUF, RON, BGN, HRK, ISK, THB, MYR, PHP, IDR, ILS, KRW

Quick start

TypeScript (free tier)

// Free tier: no x402 payment needed for first 5 queries/day/IP
const res = await fetch("https://api.devdrops.run/api/fx/latest?base=USD&symbols=GBP,EUR,JPY");
const { data } = await res.json();
// data.rates: { GBP: 0.787, EUR: 0.921, JPY: 149.3 }

TypeScript (paid, beyond free tier)

import { wrapFetchWithPayment } from "@x402/fetch";
import { CoinbaseWalletClient } from "@coinbase/wallet-sdk";

const pay = wrapFetchWithPayment(fetch, new CoinbaseWalletClient({ ... }));
const res = await pay("https://api.devdrops.run/api/fx/convert?from=USD&to=GBP&amount=1000");
const { data } = await res.json();
// data.amount: 787.42

curl

# Latest rates (may use free tier)
curl "https://api.devdrops.run/api/fx/latest"

# Convert
curl -H "x-402-payment: <proof>" \
  "https://api.devdrops.run/api/fx/convert?from=EUR&to=USD&amount=250"

Examples

Example 1: All rates against EUR

GET /api/fx/latest

{
  "product": "fx",
  "cached": true,
  "data": {
    "base": "EUR",
    "date": "2026-04-25",
    "rates": {
      "USD": 1.087,
      "GBP": 0.855,
      "JPY": 163.4,
      "CHF": 0.967
    }
  }
}

Example 2: Convert USD to multiple currencies

GET /api/fx/latest?base=USD&symbols=GBP,EUR,CAD,AUD

Example 3: Specific conversion

GET /api/fx/convert?from=GBP&to=EUR&amount=500

{
  "data": {
    "from": "GBP",
    "to": "EUR",
    "amount": 500,
    "result": 585.38,
    "rate": 1.17076,
    "date": "2026-04-25"
  }
}

Example 4: Historical rate

GET /api/fx/historical?date=2025-01-15&base=USD&symbols=GBP

Example 5: Currency normalisation agent

// Normalise a list of invoices to USD
async function normaliseToUSD(invoices: { amount: number; currency: string }[]) {
  const res = await fetch("https://api.devdrops.run/api/fx/latest?base=USD");
  const { data } = await res.json();

  return invoices.map(inv => ({
    ...inv,
    usd: inv.currency === "USD" ? inv.amount : inv.amount / data.rates[inv.currency],
  }));
}

Errors & limits

Free tier: 5 queries/day/IP on FX endpoints. Check X-Free-Tier-Remaining response header.

Caching: Latest rates cached until next ECB update (rates change once per business day). Historical rates are permanently cached.

Weekends and holidays: The ECB does not publish rates on weekends or ECB bank holidays. Historical queries for these dates will 404. Use the most recent prior business day.

Precision: Rates are provided to 5 significant figures, as published by the ECB.

Related skills

• devdrops-weather — another free-tier utility endpoint
• devdrops-prediction-markets — market probability data to pair with rates