BNB-Bank Exchange Rate API: BYN Buy and Sell Rates as JSON

BNB-Bank (Belarusian People’s Bank) is a Minsk-based commercial bank. Its home page lists app, cash and card buy and sell rates in roubles for seven currencies. This guide shows how to read that board as JSON: what the rates mean, how they compare with the National Bank of the Republic of Belarus official rate and with other banks in Belarus, and the calls that return them.

What the BNB-Bank board shows

• 6 currencies against the Belarusian ruble: CNY, EUR, GBP, PLN, RUB and USD. Every value is BYN per 1 unit of the foreign currency.
• The cash buy / sell pair. Belarusian banks quote the US dollar, euro and Russian ruble (per 100) in Belarusian rubles, with separate branch-cash and card rates that change during the day. The National Bank of the Republic of Belarus official rate is shown next to each row.
• USD on 15 November 2026: BNB-Bank bought at 2.992 and sold at 2.994 BYN, a spread of 0.07%. The National Bank of the Republic of Belarus official rate was 3.0026, so the bank's mid sat -0.32% from it.
• No timestamp on the bank's page. BNB-Bank does not print a last-updated time, so bank_updated_at is null and captured_at (when AllRatesToday read the page) is the only time available.
• Every day's board is kept permanently, from 15 November 2026, the day collection started. 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 USD (0.07%), EUR (0.68%), CNY (1.98%) and the widest GBP (6.72%), RUB (4.82%), PLN (2.79%). 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 BNB-Bank and other banks in Belarus

USD on the 7 boards AllRatesToday reads in Belarus, all captured on 15 November 2026 (the National Bank of the Republic of Belarus official rate was 3.0026):

BNB-Bank had the narrowest USD spread of the 7. One call to /api/v1/bank-rates/by 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/by/bnbby" \
  -H "Authorization: Bearer art_live_your_key"

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

{
  "bank": "bnbby",
  "name": "BNB-Bank",
  "country": "by",
  "quote_ccy": "BYN",
  "bank_updated_at": null,
  "basis": "Cash buy / sell",
  "captured_at": "2026-11-15T11:16:24.850Z",
  "rates": [
    {"ccy":"CNY","buy":0.45,"sell":0.459,"mid":0.4545,"spread_pct":1.98,"official":0.45143000000000005,"vs_official_pct":0.68},
    {"ccy":"EUR","buy":3.3065,"sell":3.329,"mid":3.31775,"spread_pct":0.678,"official":3.3312,"vs_official_pct":-0.404},
    {"ccy":"GBP","buy":3.74,"sell":4,"mid":3.87,"spread_pct":6.718,"official":3.9851,"vs_official_pct":-2.888},
    … 3 more currencies
  ],
  "disclaimer": "…",
  "attribution": { … }
}

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

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

{
  "bank": "bnbby",
  "name": "BNB-Bank",
  "country": "by",
  "quote_ccy": "BYN",
  "bank_updated_at": null,
  "basis": "Cash buy / sell",
  "captured_at": "2026-11-15T11:16:24.850Z",
  "ccy": "USD",
  "buy": 2.992,
  "sell": 2.994,
  "mid": 2.993,
  "spread_pct": 0.067,
  "official": 3.0026,
  "vs_official_pct": -0.32,
  "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 BNB-Bank on its own website, collected by AllRatesToday",
    "bank_url": "https://bnb.by/#exchange_rates",
    "url": "https://allratestoday.com/bank-exchange-rate-api/by/bnbby/",
    "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/by/bnbby?date=2026-11-15" \
  -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/by/bnbby/history?ccy=USD&from=2026-11-15&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' });

// BNB-Bank's USD row
const r = await client.bankRates('by', { bank: 'bnbby', ccy: 'USD' });
console.log(`BNB-Bank buys USD at ${r.buy}, sells at ${r.sell} BYN`);

// The board as it stood on a past day
const past = await client.bankRates('by', { bank: 'bnbby', date: '2026-11-15' });
console.log(past.snapshot_date, past.rates.length);

Python

import requests

r = requests.get(
    "https://allratestoday.com/api/v1/bank-rates/by/bnbby",
    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 National Bank of the Republic of Belarus rate is the one tax, accounting and customs rules in Belarus name; nobody transacts at it. BNB-Bank'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 National Bank of the Republic of Belarus endpoint when a rule asks for the official rate.

FAQ

Where do the BNB-Bank rates come from?

From the bank's own public rates page (https://bnb.by/#exchange_rates), read hourly. AllRatesToday does not change the numbers: each row is the buy and sell price BNB-Bank shows, with the mid, the spread and the National Bank of the Republic of Belarus rate added.

Are these the official BYN exchange rates?

No. They are BNB-Bank's retail prices for customers. The official rate in Belarus is the National Bank of the Republic of Belarus 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 BNB-Bank board updated?

AllRatesToday reads the page every hour. The bank prints no timestamp, so captured_at tells you when the rates were read.

Can I get BNB-Bank rates for a past date?

Yes, from 15 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.