OTP banka (Slovenia) Exchange Rate API: EUR Buy and Sell Rates as JSON

OTP banka d.d. is the Slovenian subsidiary of Hungary’s OTP Bank group, formed from Nova KBM. Its exchange-office list gives buying and selling rates against the euro for 11 currencies. This guide shows how to read that board as JSON: what the rates mean, how they compare with the European Central Bank official rate and with other banks in Slovenia, and the calls that return them.

What the OTP SI board shows

• 11 currencies against the euro: AUD, BAM, CAD, CHF, CZK, GBP, HUF, JPY, MKD, RSD and USD. Every value is EUR per 1 unit of the foreign currency.
• The exchange-office list (menjalniški tečaj) buy / sell pair. Slovenia uses the euro, so its banks quote other currencies as units per euro, with a buying and a selling rate either side of the European Central Bank reference rate. The rates here are converted to euros per unit. The European Central Bank official rate is shown next to each row.
• USD on 15 November 2026: OTP SI bought at 0.8865 and sold at 0.9285 EUR, a spread of 4.63%. The European Central Bank official rate was 0.9048, so the bank's mid sat +0.30% from it.
• The bank's own timestamp. The page prints a last-updated stamp (14.11.2026 07:01:00 on the board above), returned as bank_updated_at next to our captured_at.
• Every day's board is kept permanently, from 14 November 2026. Read one past day with ?date=, or a range for one currency with the /history endpoint (paid plans).

Spreads across the board

On the 15 November 2026 board the tightest spreads were AUD (4.36%), JPY (4.40%), GBP (4.43%) and the widest MKD (11.61%), RSD (7.04%), BAM (5.22%). Spread is (sell − buy) ÷ mid: what a round trip through the bank costs, before any fees. The API returns it on every row as spread_pct, so you can rank currencies or alert when a bank widens its board.

USD at OTP SI and other banks in Slovenia

USD on the 6 boards AllRatesToday reads in Slovenia, all captured on 15 November 2026 (the European Central Bank official rate was 0.9048):

OTP SI had the 4th narrowest USD spread of the 6. One call to /api/v1/bank-rates/si returns every board in the table at once.

Get the board (REST)

You need an API key; the free key works. The full board:

curl "https://allratestoday.com/api/v1/bank-rates/si/otpsi" \
  -H "Authorization: Bearer art_live_your_key"

What comes back (the 15 November 2026 board, first three rows):

{
  "bank": "otpsi",
  "name": "OTP banka (Slovenia)",
  "country": "si",
  "quote_ccy": "EUR",
  "bank_updated_at": "14.11.2026 07:01:00",
  "basis": "Exchange-office list (menjalniški tečaj) buy / sell",
  "captured_at": "2026-11-15T11:15:40.466Z",
  "rates": [
    {"ccy":"AUD","buy":0.60132291,"sell":0.6281407,"mid":0.61473181,"spread_pct":4.363,"official":0.6139489194499017,"vs_official_pct":0.128},
    {"ccy":"BAM","buy":0.49925112,"sell":0.52603893,"mid":0.51264502,"spread_pct":5.225,"official":null,"vs_official_pct":null},
    {"ccy":"CAD","buy":0.62189055,"sell":0.65019506,"mid":0.6360428,"spread_pct":4.45,"official":0.6345982992765579,"vs_official_pct":0.228},
    … 8 more currencies
  ],
  "disclaimer": "…",
  "attribution": { … }
}

One currency, with the row fields at the top level:

curl "https://allratestoday.com/api/v1/bank-rates/si/otpsi?ccy=USD" \
  -H "Authorization: Bearer art_live_your_key"

{
  "bank": "otpsi",
  "name": "OTP banka (Slovenia)",
  "country": "si",
  "quote_ccy": "EUR",
  "bank_updated_at": "14.11.2026 07:01:00",
  "basis": "Exchange-office list (menjalniški tečaj) buy / sell",
  "captured_at": "2026-11-15T11:15:40.466Z",
  "ccy": "USD",
  "buy": 0.88652482,
  "sell": 0.92850511,
  "mid": 0.90751497,
  "spread_pct": 4.626,
  "official": 0.9048136083966704,
  "vs_official_pct": 0.299,
  "disclaimer": "Retail buy/sell rates as displayed on each bank’s own website at capture time, quoted as home currency per 1 unit of foreign currency. Indicative only: banks change these through the day, apply them at the counter or in-app, and they are not official or reference rates. For the rate a regulation names, use the central-bank endpoints.",
  "attribution": {
    "source": "Board rates published by OTP banka (Slovenia) on its own website, collected by AllRatesToday",
    "bank_url": "https://www.otpbanka.si/tecajne-liste-menjalnica",
    "url": "https://allratestoday.com/bank-exchange-rate-api/si/otpsi/",
    "terms": "Public pages that show the rates need a visible link to allratestoday.com"
  }
}

The board as it stood on a past day:

curl "https://allratestoday.com/api/v1/bank-rates/si/otpsi?date=2026-11-14" \
  -H "Authorization: Bearer art_live_your_key"

One currency over a date range, one row per day (paid plans; add &format=csv, xml or xlsx for a file):

curl "https://allratestoday.com/api/v1/bank-rates/si/otpsi/history?ccy=USD&from=2026-11-14&to=2026-11-15" \
  -H "Authorization: Bearer art_live_your_key"

JavaScript

npm install @allratestoday/sdk

import { AllRatesToday } from '@allratestoday/sdk';

const client = new AllRatesToday({ apiKey: 'art_live_your_key' });

// OTP banka (Slovenia)'s USD row
const r = await client.bankRates('si', { bank: 'otpsi', ccy: 'USD' });
console.log(`OTP SI buys USD at ${r.buy}, sells at ${r.sell} EUR`);

// The board as it stood on a past day
const past = await client.bankRates('si', { bank: 'otpsi', date: '2026-11-14' });
console.log(past.snapshot_date, past.rates.length);

Python

import requests

r = requests.get(
    "https://allratestoday.com/api/v1/bank-rates/si/otpsi",
    headers={"Authorization": "Bearer art_live_your_key"},
    timeout=10,
)
r.raise_for_status()
for row in r.json()["rates"]:
    print(row["ccy"], row["buy"], row["sell"], row["spread_pct"])

Board rate or official rate?

The European Central Bank rate is the one tax, accounting and customs rules in Slovenia name; nobody transacts at it. OTP SI's board is the price a customer actually gets. The API puts both on every row: official is the central bank's rate for the same currency and vs_official_pct is how far the bank's mid sits from it. Use the board to show customers a real price, compare banks for a remittance, or keep a dated record of what the bank quoted; use the European Central Bank endpoint when a rule asks for the official rate.

FAQ

Where do the OTP banka (Slovenia) rates come from?

From the bank's own public rates page (https://www.otpbanka.si/tecajne-liste-menjalnica), read hourly. AllRatesToday does not change the numbers: each row is the buy and sell price OTP SI shows, with the mid, the spread and the European Central Bank rate added.

Are these the official EUR exchange rates?

No. They are OTP SI's retail prices for customers. The official rate in Slovenia is the European Central Bank rate, which the API returns as official on each row where the central bank has one, and in full from the central-bank endpoint.

How often is the OTP SI board updated?

AllRatesToday reads the page every hour. The bank's own last-updated stamp is returned as bank_updated_at, so you can tell a fresh read of an unchanged board from a new board.

Can I get OTP SI rates for a past date?

Yes, from 14 November 2026 onward; every day's board is kept permanently. Add ?date=YYYY-MM-DD for one day: the response is the board captured that day, or the nearest earlier day within five days, with date_requested and snapshot_date added. For a range, /history?ccy=USD&from=…&to=… returns one row per day as JSON, CSV, XML or XLSX on paid plans.

Do I need an API key?

Yes. Commercial bank boards need an API key; any plan works, the free key included, and each call counts against the plan. Public pages or widgets that show the rates need a visible link to allratestoday.com.