NBRB Exchange Rate API: Official Belarusian Ruble Rates as JSON

The National Bank of the Republic of Belarus publishes the official exchange rates that accounting, tax, and customs practice in Belarus reference — published official rates, not moving market prices. This guide shows how to pull them as JSON: via a REST endpoint or the zero-dependency nbrb-exchange-rate npm package.

Set today, official tomorrow

The NBRB sets official rates each business day and they take effect the next calendar day — Friday’s setting is already Monday’s official rate, published in advance. Belarusian accounting and tax legislation convert at this official rate, so date attribution matters: the API stores each rate under the date it is official for, exactly as the bank publishes it.

Why official rates, not market rates

A live mid-market feed answers "what is USD/BYN trading at right now?" — the right tool for checkouts and dashboards. But accountants, auditors, and tax authorities ask a different question: "which rate were you required to use for this date?" That answer comes from the National Bank of the Republic of Belarus’s published rates, and it never changes after publication.

Get the latest rates (REST)

curl "https://allratestoday.com/api/v1/central-bank/nbrb/latest" \
  -H "Authorization: Bearer YOUR_API_KEY"

The response is the bank's most recent published table — every rate and the publication date. The latest rates are available on every plan, including the free tier (300 requests/month, no credit card).

The npm SDK

npm install nbrb-exchange-rate

import { getRate, getLatestRates } from 'nbrb-exchange-rate';

// One pair at the official rate
const pair = await getRate('USD', 'BYN', { apiKey: 'art_live_...' });
console.log(pair.rate, pair.rate_date);

// The bank's full published table
const table = await getLatestRates({ apiKey: 'art_live_...' });
console.log(table.rate_date, table.rates.length);

Zero dependencies, TypeScript types included, and it runs anywhere fetch exists — Node 18+, Bun, Deno, and edge runtimes.

Historical rates for an invoice date

import { getRatesForDate, getHistory } from 'nbrb-exchange-rate';

const day = await getRatesForDate('2026-08-18', { apiKey: 'art_live_...' });

const series = await getHistory(
  { source: 'USD', target: 'BYN', from: '2026-01-01' },
  { apiKey: 'art_live_...' }
);

Historical dates and time series need a paid plan; the latest rates stay free.

Published vs derived pairs

If the National Bank of the Republic of Belarus does not print a pair directly, the API resolves it from the bank's published rates — an inverse, or a cross via BYN — and flags it derived: true with the method used. Official and computed values are never silently mixed, which is exactly the distinction an auditor will ask about.

The archive

The archive is loaded from July 2016 — the start of the current (post-redenomination) ruble, so the stored series is one continuous unit with no 10,000:1 breaks inside it.

FAQ

Does the National Bank of the Republic of Belarus have an official exchange rate API?

The bank publishes its official rates on its own site, and AllRatesToday serves the same published rates as clean JSON via REST or the nbrb-exchange-rate npm package. The latest table is free.

How do I get the official Belarus exchange rate for a past date?

The rates-for-date endpoint returns the official table for any archived date; non-publication days resolve to the most recent published date and are flagged, so audit trails stay honest. Historical dates require a paid plan; latest rates are free.

Why does the API sometimes return a rate dated tomorrow?

Because the bank publishes it today: NBRB rates are set in the afternoon and are official for the following calendar day. The forward-dated value is the official rate for that date.