Pricing
Currency API pricing, never by the seat.
Start on the open endpoint without an account. Add a key and a 5,000-request signup bonus is yours, along with the full response and every reading we store — a month back or a year, the same call. Top up only if you ever need to, once, with nothing renewing behind it.
- Billing
- USD · PayPal
- Commitment
- None · no auto-renewal
- Open endpoint
- 5/sec · 50/day
Public
Freeno account needed
One open endpoint for evaluation, prototypes and low-volume checks.
- 5 requests per second
- 50 requests per hour
- 50 requests per day
- Latest rates and full catalogue
Free account
Most used$0signup bonus
The full response, every stored reading by date, and a signup bonus waiting when you arrive.
- 5,000-request signup bonus
- No rate limit on keyed calls
- Latest rates, catalogue and full history
- Any date range via ?from and ?to
- Unlimited keys, one shared balance
- No card, no commitment, no expiry
Top-ups
From $4one-time
More headroom when the balance runs down: 2,000 requests up to 100,000, bought once.
- Added to your balance permanently
- Never expires, never renews
- Credited the moment payment clears
- Applies to every key on the account
- Not included
- A subscription — packs are bought once and never renew
Public windows reset on the UTC clock · account balances never reset
Top-up packs
Buy the requests you need, once.
Six packs, from $4 to $87.50. Each one adds requests to the balance of the account that buys it, applies to every key on that account, and never expires.
- 2,000requests$4total$2.00/1k
- 7,500requests$12total$1.60/1k
- 15,000requests$20total$1.333/1k
- 40,000requests$45total$1.125/1k
- 50,000requests$65total$1.30/1k
- 100,000requests$87.50total$0.875/1k
Payment is taken by PayPal on its own checkout page. Requests are credited the moment the capture is confirmed server-side.
Open top-upsEvery level includes
- Latest rates for every published currency
- Official name, symbol and flag per code
- Any base currency via ?base
- JSON over HTTPS with CORS enabled
- Remaining balance on every keyed response
Not part of the price
- A guaranteed uptime SLA
- Redistribution of the feed as a data service
- Anything recurring — no subscription, no renewal date
Need an SLA, a bulk history export or a redistribution licence? Write to duplexinterface@outlook.com and we will scope it.
Billing detail
No surprises after the first month.
When you are charged
Only when you buy a top-up, and only once. There is no card on file, no trial that turns into a charge, and nothing to cancel.
What never resets
Your signup bonus of 5,000 requests is waiting the moment the account exists. Nothing renews automatically and nothing expires with the calendar — a top-up simply adds to what you already hold.
If you need money back
Unused top-ups are refundable within 14 days of payment through PayPal. The refund policy sets out the detail.
Refund policyStart now
Quote any price in any currency.
Create an account and 5,000 requests are waiting for you — plus every reading we have stored. Mint a key, make your first call in a minute, and try the open endpoint right now if you would rather look first.