Currency Exchange Rates · Data API

Global Currency Exchange Rates

Official exchange rates for converting more than 160 world currencies into US dollars.

A dated table of official foreign currency exchange rates published by the US Treasury, covering every currency the US government transacts in. Each row gives a country, its currency, the effective date and the rate used to convert that currency into US dollars. Finance, accounting, invoicing and cross-border commerce teams use it as an auditable, government-sourced alternative to commercial FX feeds.

Source: Treasury Reporting Rates of Exchange, US Department of the Treasury (Fiscal Data) · Public domain (US Government work, free to use per Fiscal Data licence) · Source: U.S. Department of the Treasury, Fiscal Data (fiscaldata.treasury.gov)

Endpoints

Every request is authenticated with your X-API-Key and counted against your plan.

  • GET /v1/data/global-currency-exchange-rates
  • GET /v1/data/global-currency-exchange-rates/search?q=...
  • GET /v1/data/global-currency-exchange-rates/{key}

Base path /v1/data/global-currency-exchange-rates · full reference in the interactive docs. Also exposed as an MCP tool for AI agents.

Fields

FieldTypeDescription
record_datedateDate the rate was published in the Treasury report
countrystrCountry or issuing authority of the currency
currencystrCurrency name, for example Dollar or Euro
country_currency_descstrCombined country and currency label, for example Australia-Dollar
exchange_ratefloatUnits of the foreign currency per one US dollar
effective_datedateDate from which the rate applies
record_calendar_yearintCalendar year of the published rate
record_calendar_monthintCalendar month of the published rate

What you get

Rates for 160+ currencies with full history back through prior reporting periods
Filter by country, currency or reporting date in a single call
Government-published rates that stand up to audit and tax review
Stable JSON schema with no per-call FX metering
Model Context Protocol tool so agents can convert amounts directly

FAQ

How often do the rates change?
The Treasury publishes rates quarterly, with amendments in between when a currency moves sharply. We refresh from the source on our normal ingest schedule.
Are these live market rates?
No. They are official government reporting rates intended for accounting and reporting, not for intraday trading or settlement.
Which direction is the rate?
exchange_rate is the number of units of the foreign currency equal to one US dollar.

Pricing

Simple, transparent pricing

Start free, upgrade when you need more. All plans include full API access.

Free

$0forever

Get started and explore the API

100 requests/day
  • 100 API requests per day
  • All endpoints included
  • Community support
Most popular

Pro

$9/month

For production apps and AI agents

10,000 requests/day
  • 10,000 API requests per day
  • All endpoints included
  • Priority support
  • Usage dashboard

Enterprise

$49/month

Unlimited access for high-volume use

Unlimited requests
  • Unlimited API requests
  • All endpoints included
  • Priority support
  • Usage dashboard
  • Dedicated support channel

Getting Started

Start building in minutes

Register for a free API key, make your first request, and upgrade when you're ready.

1

Register

Create an account to get your API key. It's free — no credit card required.

curl -X POST https://api.aristocles.com.au/v1/auth/register \
  -H "Content-Type: application/json" \
  -d '{"email": "you@example.com", "name": "Your Name"}'
2

Make a request

Use your API key in the X-API-Key header to authenticate requests.

curl https://api.aristocles.com.au/v1/data/asx \
  -H "X-API-Key: your_api_key_here"
3

Upgrade

Need more requests? Upgrade to Pro or Enterprise — you'll be redirected to Stripe Checkout.

curl -X POST "https://api.aristocles.com.au/v1/billing/checkout?tier=pro" \
  -H "X-API-Key: your_api_key_here"
4

Check usage

Monitor your daily request count and remaining quota at any time.

curl https://api.aristocles.com.au/v1/usage \
  -H "X-API-Key: your_api_key_here"