Bank of Canada Exchange Rate API: Official CAD Rates as JSON

Bank of Canada publishes an official table of exchange rates once per business day — the daily exchange rates — covering ~27 currencies against the CAD. These are the published central bank rates used for tax filings, customs valuations, audits, and compliant invoicing in Canada — not moving market prices. This guide shows how to pull them as JSON: via a REST endpoint or the zero-dependency boc-exchange-rate npm package, with history back to 2017.

What the Bank of Canada publishes

• ~27 currencies against the CAD, in one table per business day.
• History back to 2017 — queryable by exact date or as a daily time series.
• The bank's own publication date on every response, so a rate is always citable.
• No weekend or holiday gaps to trip over — requests for non-publication days resolve to the most recent published table and are flagged explicitly.

Why official rates, not market rates

A live mid-market exchange rate API answers "what is USD/CAD 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 central bank's published table, and it never changes after publication.

The Bank of Canada's daily rates are the reference the CRA accepts for CAD conversion, which makes them the default for Canadian invoicing, tax filings, and audit support.

Get the latest table (REST)

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

The response is the bank's most recent published table — one row per published pair in the bank's own quoting direction, the publication date (rate_date), and a freshness flag. Live example captured 2026-10-09:

{
  "bank": "boc",
  "name": "Bank of Canada",
  "rate_date": "2026-10-09",
  "age_days": 1,
  "stale": false,
  "cadence": "daily",
  "rates": [
    {"base": "AUD", "quote": "CAD", "type": "indicative", "value": 0.9958},
    {"base": "BRL", "quote": "CAD", "type": "indicative", "value": 0.286},
    {"base": "CHF", "quote": "CAD", "type": "indicative", "value": 1.718},
    … 21 more rows
  ],
  "disclaimer": "Official rates as published by the named central bank. On weekends/holidays the most recent published rate_date is returned."
}

Most integrations need one pair. Add source and target and the API returns a single resolved rate — derived: false when Bank of Canada printed the pair itself:

curl "https://allratestoday.com/api/v1/central-bank/boc/latest?source=USD&target=CAD" \
  -H "Authorization: Bearer YOUR_API_KEY"

{
  "bank": "boc",
  "name": "Bank of Canada",
  "rate_date": "2026-10-09",
  "source": "USD",
  "target": "CAD",
  "rate": 1.4271,
  "rate_type": "indicative",
  "derived": false,
  "method": "published",
  "age_days": 1,
  "stale": false,
  "cadence": "daily",
  "disclaimer": "Official rates as published by the named central bank. On weekends/holidays the most recent published rate_date is returned."
}

The latest table is available on every plan, including the free tier (no credit card). Since the table changes once per business day, caching it locally makes even a small quota go a long way.

The npm SDK

npm install boc-exchange-rate

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

// One pair at the official Bank of Canada rate
const pair = await getRate('USD', 'CAD', { 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

The most common compliance job: an invoice dated months ago needs the official rate for that date.

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

// The official table for an invoice date — weekends/holidays return
// the most recent published date, flagged via published_on_requested_date.
const day = await getRatesForDate('2026-06-30', { apiKey: 'art_live_...' });

// Daily series for one pair
const series = await getHistory(
  { source: 'USD', target: 'CAD', from: '2026-01-01' },
  { apiKey: 'art_live_...' }
);

Historical dates and time series need a paid plan; the latest table stays free.

Published vs derived pairs

If the Bank of Canada does not print a pair directly, the API resolves it from the bank's table — an inverse, or a cross rate via CAD — 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.

FAQ

Does Bank of Canada have an official exchange rate API?

Bank of Canada publishes its official rates on its website, but not always in a developer-friendly form. AllRatesToday serves the bank's published table as clean JSON — ~27 currencies against the CAD, with history back to 2017 — via REST or the boc-exchange-rate npm package. The latest table is free.

How often do Bank of Canada rates update?

Once per business day. These are published reference rates, not moving market prices — the table changes when the Bank of Canada publishes a new one, and every API response carries the bank's own publication date so you can cite it.

Can I get the Bank of Canada rate for a past date, like an invoice date?

Yes. The /central-bank/boc/rates-for-date endpoint returns the official table for any date back to 2017. Weekends and holidays resolve to the most recent published table and are flagged, so your audit trail stays honest. Historical dates require a paid plan; latest rates are free.