How to Get the SELIC (SELIC) Rate

How to Get the SELIC (SELIC) Rate

You need the Brazilian SELIC policy rate inside your software, reliably and with minimal friction. By the end of this guide, you will query the SELIC rate over a clean REST API, parse its latest and historical values, compute ranges and candlesticks, and fold it into spread calculations and loan math without guesswork.

What the SELIC (SELIC) Rate Represents

SELIC is Brazil’s central bank target rate that anchors short-term interest rates in BRL. In the Interest Rates API, the SELIC symbol identifies the headline target rate as a percentage per annum. SELIC is modeled as monthly in the symbol catalogue; you should treat the effective date as the day the rate is in force for a given month or the last available day for that month when pulling “historical” by an in-month date.

Illustration: How to Get the SELIC (SELIC) Rate

The JSON payloads return plain numeric percentage values (e.g., 13.75) and an explicit date for each symbol in the dates map. Always interpret the number as percent (not decimal fraction). For example, a value of 13.75 means 13.75% per annum.

Base URL, Authentication, and Method

  • Base URL: https://interestratesapi.com/api/v1/
  • Method: GET for all endpoints
  • Authentication: api_key query parameter

All requests are read-only GET requests and must append ?api_key=YOUR_API_KEY (or pass it as a query parameter when using a client library). Explore the API product and docs at interestratesapi.com and the method catalog at MCP.

Quick Start: Get the Latest SELIC

Use the Latest endpoint to fetch the most recent published SELIC value. The following cURL and JSON response are the official sample. The value is expressed in BRL terms and the number itself is a percent per annum figure.

curl -s "https://interestratesapi.com/api/v1/latest?api_key=YOUR_API_KEY&symbols=SELIC"
{
    "success": true,
    "date": "2026-09-30",
    "base": "BRL",
    "rates": {
        "SELIC": 13.75
    },
    "dates": {
        "SELIC": "2026-09-30"
    },
    "currencies": {
        "SELIC": "BRL"
    },
    "base_filter_note": null
}

How to read this:

  • rates.SELIC: the SELIC rate as a percent per annum.
  • dates.SELIC: the effective date for the value returned.
  • currencies.SELIC: BRL, the currency associated with the rate context.
  • date: the API’s unified as-of date for the response.

Latest in Python (requests)

import requests

resp = requests.get(
'https://interestratesapi.com/api/v1/latest',
params={'symbols': 'SELIC', 'api_key': 'YOUR_API_KEY'}
)
data = resp.json()

selic = data['rates']['SELIC']
selic_date = data['dates']['SELIC']
currency = data['currencies']['SELIC']
print(f"SELIC: {selic}% on {selic_date} ({currency})")

Latest in JavaScript (fetch)

const response = await fetch(
'https://interestratesapi.com/api/v1/latest?symbols=SELIC&api_key=YOUR_API_KEY'
);
const data = await response.json();

const selic = data.rates.SELIC;
const date = data.dates.SELIC;
const currency = data.currencies.SELIC;
console.log(`SELIC: ${selic}% on ${date} (${currency})`);

Latest in PHP

<?php
$url = 'https://interestratesapi.com/api/v1/latest?symbols=SELIC&api_key=YOUR_API_KEY';
$json = file_get_contents($url);
$data = json_decode($json, true);

$selic = $data['rates']['SELIC'];
$date = $data['dates']['SELIC'];
$ccy = $data['currencies']['SELIC'];
echo "SELIC: {$selic}% on {$date} ({$ccy})";
?>

Tip: Cache this response for the remainder of the business day to reduce calls. The SELIC symbol is monthly; you typically won’t see intraday changes. Your app can refresh once per day or when your internal data pipeline rolls over.

Discover the Symbol in the Catalogue

Use the Symbols endpoint to confirm SELIC is available and to inspect its attributes (like frequency and category). You can filter by category central_bank or by currency. The rate is listed under symbol SELIC and category central_bank.

Symbols: cURL

Response format (example structure; values are illustrative as provided in the API reference):

Symbols: Python

import requests

resp = requests.get(
'https://interestratesapi.com/api/v1/symbols',
params={'category': 'central_bank', 'api_key': 'YOUR_API_KEY'}
)
symbols = resp.json()['symbols']
selic_meta = next((s for s in symbols if s['symbol'] == 'SELIC'), None)
print(selic_meta)

Symbols: JavaScript

const res = await fetch(
'https://interestratesapi.com/api/v1/symbols?category=central_bank&api_key=YOUR_API_KEY'
);
const payload = await res.json();
const selic = payload.symbols.find(s => s.symbol === 'SELIC');
console.log(selic);

Symbols: PHP

<?php
$q = 'https://interestratesapi.com/api/v1/symbols?category=central_bank&api_key=YOUR_API_KEY';
$data = json_decode(file_get_contents($q), true);
$selic = null;
foreach ($data['symbols'] as $s) {
if ($s['symbol'] === 'SELIC') { $selic = $s; break; }
}
var_dump($selic);
?>

Get SELIC on a Specific Date

When you need the SELIC value for a particular point-in-time, use the Historical endpoint. For monthly symbols, the API uses the last day with data within the target month if you pass any date inside that month.

Historical: cURL

JSON example (values are illustrative as provided in the API reference):

Historical: Python

import requests

params = {'date': '2025-06-15', 'symbols': 'SELIC', 'api_key': 'YOUR_API_KEY'}
r = requests.get('https://interestratesapi.com/api/v1/historical', params=params)
data = r.json()
value = data['rates']['SELIC']
print(value)

Historical: JavaScript

const url = new URL('https://interestratesapi.com/api/v1/historical');
url.searchParams.set('date', '2025-06-15');
url.searchParams.set('symbols', 'SELIC');
url.searchParams.set('api_key', 'YOUR_API_KEY');

const r = await fetch(url.toString());
const d = await r.json();
console.log(d.rates.SELIC);

Historical: PHP

<?php
$u = 'https://interestratesapi.com/api/v1/historical?date=2025-06-15&symbols=SELIC&api_key=YOUR_API_KEY';
$d = json_decode(file_get_contents($u), true);
echo $d['rates']['SELIC'];
?>

Build a SELIC Time Series

For charting, regressions, or backtesting rule logic, request a date-bounded series. Even though SELIC is monthly in the catalogue, the API’s sample shows daily keys in the returned map and a frequency field to help you understand the granularity.

Time Series: cURL

JSON example (values are illustrative as provided in the API reference):

Time Series: Python

import requests

params = {
'start': '2025-10-31', 'end': '2026-10-31',
'symbols': 'SELIC',
'api_key': 'YOUR_API_KEY'
}
r = requests.get('https://interestratesapi.com/api/v1/timeseries', params=params)
ts = r.json()
series = ts['rates']['SELIC'] # dict of date -> value
print(list(series.items())[:5])

Time Series: JavaScript

const res = await fetch(
'https://interestratesapi.com/api/v1/timeseries?start=2025-10-31&end=2026-10-31&symbols=SELIC&api_key=YOUR_API_KEY'
);
const payload = await res.json();
const series = payload.rates.SELIC;
console.log(Object.entries(series).slice(0, 5));

Time Series: PHP

<?php
$url = 'https://interestratesapi.com/api/v1/timeseries?start=2025-10-31&end=2026-10-31&symbols=SELIC&api_key=YOUR_API_KEY';
$data = json_decode(file_get_contents($url), true);
$series = $data['rates']['SELIC'];
print_r(array_slice($series, 0, 5, true));
?>

Measure SELIC Changes Over a Range

Quantify the level change, percentage change, and extrema with the Fluctuation endpoint. This is useful for dashboards, alerts, and risk attribution.

Fluctuation: cURL

JSON example (values are illustrative as provided in the API reference):

Fluctuation: Python

import requests

p = {'start': '2025-10-31', 'end': '2026-10-31', 'symbols': 'SELIC', 'api_key': 'YOUR_API_KEY'}
d = requests.get('https://interestratesapi.com/api/v1/fluctuation', params=p).json()
fl = d['rates']['SELIC']
print(fl['change'], fl['change_pct'], fl['high'], fl['low'])

Fluctuation: JavaScript

const url = 'https://interestratesapi.com/api/v1/fluctuation?start=2025-10-31&end=2026-10-31&symbols=SELIC&api_key=YOUR_API_KEY';
const data = await (await fetch(url)).json();
const f = data.rates.SELIC;
console.log(f.change, f.change_pct, f.high, f.low);

Fluctuation: PHP

<?php
$u = 'https://interestratesapi.com/api/v1/fluctuation?start=2025-10-31&end=2026-10-31&symbols=SELIC&api_key=YOUR_API_KEY';
$f = json_decode(file_get_contents($u), true)['rates']['SELIC'];
echo "{$f['change']} ({$f['change_pct']}%), high={$f['high']}, low={$f['low']}";
?>

Compute OHLC Candles for SELIC

For charting or analytics that expect candlestick inputs, use OHLC. The endpoint computes candles on-the-fly from daily data for the requested period aggregation.

OHLC: cURL

JSON example (values are illustrative as provided in the API reference):

OHLC: Python

import requests

params = {
'symbols': 'SELIC', 'period': 'monthly',
'start': '2025-10-31', 'end': '2026-10-31',
'api_key': 'YOUR_API_KEY'
}
d = requests.get('https://interestratesapi.com/api/v1/ohlc', params=params).json()
candles = d['rates']['SELIC']
for c in candles:
print(c['period'], c['open'], c['high'], c['low'], c['close'], c['data_points'])

OHLC: JavaScript

const o = await fetch(
'https://interestratesapi.com/api/v1/ohlc?symbols=SELIC&period=monthly&start=2025-10-31&end=2026-10-31&api_key=YOUR_API_KEY'
).then(r => r.json());
console.log(o.rates.SELIC);

OHLC: PHP

<?php
$u = 'https://interestratesapi.com/api/v1/ohlc?symbols=SELIC&period=monthly&start=2025-10-31&end=2026-10-31&api_key=YOUR_API_KEY';
$d = json_decode(file_get_contents($u), true);
print_r($d['rates']['SELIC']);
?>

Compare Interest Costs Using SELIC

If you need a quick comparison of simple-loan interest costs at the latest rate of two symbols, use the Convert endpoint. It returns total interest and total payment for a notional amount and term, plus the spread between the two rates. This is helpful for client-facing tools or internal benchmarking.

Convert: cURL

JSON example (values are illustrative as provided in the API reference):

Convert: Python

import requests

params = {
'from': 'SELIC',
'to': 'ECB_MRO',
'amount': 100000,
'term_months': 12,
'api_key': 'YOUR_API_KEY'
}
d = requests.get('https://interestratesapi.com/api/v1/convert', params=params).json()
print(d['difference']['rate_spread'], d['difference']['interest_saved'])

Convert: JavaScript

const url = 'https://interestratesapi.com/api/v1/convert?from=SELIC&to=ECB_MRO&amount=100000&term_months=12&api_key=YOUR_API_KEY';
const out = await (await fetch(url)).json();
console.log(out.difference.rate_spread, out.difference.interest_saved);

Convert: PHP

<?php
$u = 'https://interestratesapi.com/api/v1/convert?from=SELIC&to=ECB_MRO&amount=100000&term_months=12&api_key=YOUR_API_KEY';
$d = json_decode(file_get_contents($u), true);
echo $d['difference']['rate_spread'] . ' ' . $d['difference']['interest_saved'];
?>

Operational Details That Save Time

  • Frequency and effective dates: SELIC is monthly in the symbol catalogue. When you query /historical with a date inside a month, the API returns the last available day in that month with data for that symbol. In /latest, use the dates map to read the specific effective date.
  • Business days and weekends: Central bank target rates do not change every business day. Cache the /latest response for the day (or until your pipeline signals a rate decision or month rollover). For time series used in daily dashboards, a rate can carry forward across multiple days if unchanged.
  • Units: JSON numbers are percentages per annum. Do not divide by 100 unless your math library expects a decimal rate (e.g., 13.75% becomes 0.1375).
  • Caching: Cache results at the endpoint+query level. For example, you can cache /latest?symbols=SELIC for 6–24 hours depending on your SLA. For historical/time series with fixed date bounds, you can cache indefinitely.
  • Error handling: On quota exhaustion, honor the Retry-After and read X-RateLimit-* headers. On 404 with details, surface the available ranges to users. On 422, re-validate your date format (Y-m-d) and symbol.

Computing Spreads, Monthly Payments, and Carry

Spreads: To compute the spread between the latest SELIC and another benchmark (e.g., ECB_MRO), pull both via /latest and subtract: spread_pct = selic_pct - other_pct. If your app requires basis points, multiply by 100: spread_bp = spread_pct * 100.

Simple monthly interest cost: If your product models simple interest (as in the Convert endpoint), total interest over N months is total_interest = principal * (annual_rate_pct / 100) * (N / 12). Monthly interest-only payment would be interest_only_monthly = principal * (annual_rate_pct / 100) / 12. If you use amortizing formulas, convert the annual rate to a monthly rate: r_m = (annual_rate_pct / 100) / 12 and apply the standard annuity formula for EMI. Do not assume compounding unless your product explicitly uses it.

Exposure and carry: For treasury analytics, you can multiply the annualized percentage by your BRL notional to estimate annual carry. When you need more granular PnL attribution, pair /timeseries with /fluctuation to isolate level changes across reporting windows.

Interpreting Key Response Fields

  • rates: A symbol-to-number map with percent-per-annum values, e.g., "SELIC": 13.75.
  • dates: The effective date per symbol. Use this as your authoritative timestamp for the rate value.
  • currencies: The currency code in the rate context (SELIC reports with BRL in /latest official sample).
  • frequencies (time series): The server-computed frequency for each symbol, useful for resampling logic.
  • change and change_pct (fluctuation): Absolute and percentage change between start_value and end_value. Null when start_value is zero.
  • open/high/low/close and data_points (ohlc): Aggregated candle values and the number of daily observations used for that period.

Common Pitfalls to Avoid

  • Using headers for auth: This API authenticates strictly via query parameter api_key, not headers.
  • Using POST: All endpoints are GET only.
  • Assuming intraday variability: SELIC is monthly; plan refresh at a daily or monthly cadence.
  • Dropping the effective date: Persist the date from dates.SELIC to ensure consistent point-in-time analysis.
  • Unit confusion: The numeric values are percentages, not decimals.

End-to-End Example: Build a Minimal SELIC Dashboard

To assemble an internal dashboard:

  1. Fetch /latest for SELIC at startup and cache the response for the session. Display the percent and effective date.
  2. Request a 2–3 year /timeseries to populate a line chart. Use the frequencies field to align x-axis ticks.
  3. Use /fluctuation for YTD and 1Y change widgets, including change, change_pct, and high/low.
  4. Offer a /convert comparison against a peer policy rate (e.g., ECB_MRO) for client education or treasury what-if analysis.
  5. For candlestick visualizations, call /ohlc with period=monthly.

If you need to expand beyond SELIC later, discover more central bank and interbank symbols via /symbols. See the method catalog at interestratesapi.com.

FAQ

What does the SELIC number represent in the payload?
It is the SELIC target rate in percent per annum. For example, a value of 13.75 means 13.75% p.a. The dates.SELIC field indicates the specific effective date for that value.

How often does SELIC update?
SELIC is monthly in the symbol catalogue. You won’t typically see day-to-day changes. Refresh daily or around known policy decision windows, and always read the effective date in the response.

How should I cache SELIC responses?
Cache /latest for the business day or until your job cycle detects a new month or policy event. Historical, timeseries, fluctuation, and OHLC outputs with fixed dates can be cached indefinitely.

How do I compute a spread from SELIC to another rate?
Call /latest for both symbols and compute spread_pct = selic_pct - other_pct. Convert to bp via spread_bp = spread_pct * 100. If you need simple interest cost comparisons, use /convert.

What errors should I handle?
Expect 401 for missing/invalid keys, 403 for inactive accounts, 404 when data is unavailable for the date/range, 422 for validation errors (e.g., invalid date format), and 429 for rate limits. Read Retry-After and X-RateLimit-* headers on 429.

Get Your Key and Ship

Register to obtain your API key and start building with the SELIC rate today. Use the method catalog at MCP for endpoint details, and sign up here: Register. Learn more about the platform at interestratesapi.com and get your integration into production with a minimal surface area.

Keywords
SELIC rate API Brazilian SELIC policy REST API integration query SELIC values financial data parsing

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