Exchange Rate API

Introduction

The Exchange Rate API provides accurate mid-market currency rates sourced from 15+ central banks, commercial banks, and financial data providers. The API is REST-based, returns JSON, and supports HTTPS only.

Base URL for all requests:

Base URL

https://api.exchangerate-intel.com

All responses include a timestamp (Unix epoch) and source field indicating which data provider served the rate.

Authentication

All endpoints (except /v1/currencies) require an API key passed as a request header:

Header

X-API-Key: er_live_your_api_key_here

Keys are prefixed with er_live_ for production and er_test_ for sandbox. Never expose keys in client-side code.

Note: The /v1/currencies endpoint is public and does not require authentication.

Quickstart

Fetch the latest USD → EUR rate in under a minute:

cURL

curl -H "X-API-Key: er_live_YOUR_KEY" \
  https://api.exchangerate-intel.com/v1/latest?base=USD&symbols=EUR,GBP,JPY

Python

import requests

headers = {"X-API-Key": "er_live_YOUR_KEY"}
params = {"base": "USD", "symbols": "EUR,GBP,JPY"}
r = requests.get(
    "https://api.exchangerate-intel.com/v1/latest",
    headers=headers, params=params
)
data = r.json()
print(data["rates"])

JavaScript

const res = await fetch(
  "https://api.exchangerate-intel.com/v1/latest?base=USD&symbols=EUR,GBP,JPY",
  { headers: { "X-API-Key": "er_live_YOUR_KEY" } }
);
const data = await res.json();
console.log(data.rates);

Go

req, _ := http.NewRequest("GET",
  "https://api.exchangerate-intel.com/v1/latest?base=USD&symbols=EUR,GBP,JPY", nil)
req.Header.Set("X-API-Key", "er_live_YOUR_KEY")
resp, _ := http.DefaultClient.Do(req)

Supported Sources

Exchange Rate API aggregates data from multiple authoritative sources to provide the most accurate mid-market rates. The source field in each response tells you which provider served that particular rate.

Source ID	Provider	Update Frequency
ecb	European Central Bank	Daily (16:00 CET)
fed	US Federal Reserve	Daily (17:00 EST)
boe	Bank of England	Daily (16:30 GMT)
imf	International Monetary Fund	Daily
xe	XE Mid-Market	Every 60 seconds
reuters	Reuters FX	Every 60 seconds
bloomberg	Bloomberg FX	Every 60 seconds
coinbase	Coinbase Pro	Every 10 seconds (crypto)

Tip: Use ?source=ecb to pin requests to a specific provider. Omitting the parameter uses the highest-quality available source.

Rate Limits

Rate limits are enforced per API key based on your plan:

Plan	Monthly Quota	Requests / Second
Free	1,000	1
Starter	100,000	10
Growth	1,000,000	50
Business	10,000,000	200
Enterprise	Unlimited	Custom

When you exceed the rate limit, the API returns 429 Too Many Requests. Check the X-RateLimit-Remaining and X-RateLimit-Reset headers to track usage.

Error Codes

HTTP Code	Error	Description
400	invalid_params	Missing or invalid query parameters
401	unauthorized	Missing or invalid API key
403	forbidden	Feature not available on current plan
404	not_found	Currency code or date not found
422	unsupported_currency	Currency code not supported
429	rate_limit_exceeded	Monthly quota or per-second limit hit
500	server_error	Internal server error — retry with backoff

Error Response

{
  "error": "unsupported_currency",
  "message": "Currency code 'XYZ' is not supported",
  "status": 422
}

API Playground

Test live requests directly from the browser. Your API key is sent securely.

Interactive Request Builder

URL:

https://api.exchangerate-intel.com/v1/latest

// Response will appear here

GET/v1/latest

Returns the latest mid-market exchange rates for all or selected currencies relative to a base currency.

Query Parameters

Parameter	Type	Description
baseoptional	string	Base currency ISO 4217 code. Default: `USD`
symbolsoptional	string	Comma-separated list of target currencies. Omit for all 170+
sourceoptional	string	Preferred data source (e.g. `ecb`, `xe`)

Response

200 OK

{
  "base": "USD",
  "timestamp": 1711267200,
  "source": "xe",
  "rates": {
    "EUR": 0.921834,
    "GBP": 0.787261,
    "JPY": 151.423,
    "CAD": 1.35612,
    "AUD": 1.52038,
    "CHF": 0.89741,
    "CNY": 7.22890
  }
}

cURL

curl -H "X-API-Key: er_live_YOUR_KEY" \
  "https://api.exchangerate-intel.com/v1/latest?base=USD&symbols=EUR,GBP,JPY"

Python

r = requests.get(
    "https://api.exchangerate-intel.com/v1/latest",
    headers={"X-API-Key": "er_live_YOUR_KEY"},
    params={"base": "USD", "symbols": "EUR,GBP,JPY"}
)

JavaScript

const res = await fetch(
  "https://api.exchangerate-intel.com/v1/latest?base=USD&symbols=EUR,GBP,JPY",
  { headers: { "X-API-Key": "er_live_YOUR_KEY" } }
);

GET/v1/historical

Returns exchange rates for a specific historical date. Supported back to 1999-01-01 for major fiat pairs.

Query Parameters

Parameter	Type	Description
daterequired	string	Date in `YYYY-MM-DD` format
baseoptional	string	Base currency code. Default: `USD`
symbolsoptional	string	Comma-separated target currencies

Response

200 OK

{
  "base": "USD",
  "date": "2020-01-15",
  "source": "ecb",
  "historical": true,
  "rates": {
    "EUR": 0.89720,
    "GBP": 0.76381,
    "JPY": 109.872
  }
}

cURL

curl -H "X-API-Key: er_live_YOUR_KEY" \
  "https://api.exchangerate-intel.com/v1/historical?date=2020-01-15&base=USD&symbols=EUR,GBP,JPY"

Python

r = requests.get(
    "https://api.exchangerate-intel.com/v1/historical",
    headers={"X-API-Key": "er_live_YOUR_KEY"},
    params={"date": "2020-01-15", "base": "USD"}
)

GET/v1/range

Returns day-by-day exchange rates between two dates. Ideal for chart rendering, trend analysis, and reporting.

Query Parameters

Parameter	Type	Description
startrequired	string	Start date `YYYY-MM-DD`
endrequired	string	End date `YYYY-MM-DD`
baseoptional	string	Base currency. Default: `USD`
symbolsoptional	string	Target currencies to include

Response

200 OK

{
  "base": "USD",
  "start": "2024-01-01",
  "end": "2024-01-03",
  "rates": {
    "2024-01-01": { "EUR": 0.91920, "GBP": 0.78801 },
    "2024-01-02": { "EUR": 0.92031, "GBP": 0.78912 },
    "2024-01-03": { "EUR": 0.91885, "GBP": 0.78734 }
  }
}

cURL

curl -H "X-API-Key: er_live_YOUR_KEY" \
  "https://api.exchangerate-intel.com/v1/range?start=2024-01-01&end=2024-01-03&base=USD&symbols=EUR,GBP"

GET/v1/convert

Converts an amount from one currency to another using the latest or a historical rate.

Query Parameters

Parameter	Type	Description
fromrequired	string	Source currency ISO code (e.g. `USD`)
torequired	string	Target currency ISO code (e.g. `EUR`)
amountrequired	number	Amount to convert
dateoptional	string	Use historical rate for this date (`YYYY-MM-DD`)
precisionoptional	integer	Decimal places in result (2–8). Default: `6`

Response

200 OK

{
  "from": "USD",
  "to": "EUR",
  "amount": 1000,
  "rate": 0.921834,
  "result": 921.834,
  "timestamp": 1711267200,
  "source": "xe",
  "historical": false
}

cURL

curl -H "X-API-Key: er_live_YOUR_KEY" \
  "https://api.exchangerate-intel.com/v1/convert?from=USD&to=EUR&amount=1000"

Python

r = requests.get(
    "https://api.exchangerate-intel.com/v1/convert",
    headers={"X-API-Key": "er_live_YOUR_KEY"},
    params={"from": "USD", "to": "EUR", "amount": 1000}
)

JavaScript

const res = await fetch(
  "https://api.exchangerate-intel.com/v1/convert?from=USD&to=EUR&amount=1000",
  { headers: { "X-API-Key": "er_live_YOUR_KEY" } }
);

GET/v1/currencies

Returns the full list of all 170+ supported currencies with their ISO codes, names, and symbols. This endpoint is public — no API key required.

Response

200 OK

{
  "currencies": {
    "USD": {
      "name": "United States Dollar",
      "symbol": "$",
      "type": "fiat"
    },
    "EUR": {
      "name": "Euro",
      "symbol": "€",
      "type": "fiat"
    },
    "BTC": {
      "name": "Bitcoin",
      "symbol": "₿",
      "type": "crypto"
    },
    "XAU": {
      "name": "Gold (troy ounce)",
      "symbol": "Au",
      "type": "metal"
    }
  },
  "count": 172
}

cURL (no key needed)

curl https://api.exchangerate-intel.com/v1/currencies

GET/v1/sources

Returns metadata for all available data sources including their current status, last update time, and supported currencies.

Response

200 OK

{
  "sources": [
    {
      "id": "xe",
      "name": "XE Mid-Market",
      "status": "active",
      "last_updated": 1711267140,
      "update_frequency_seconds": 60,
      "currency_count": 172
    },
    {
      "id": "ecb",
      "name": "European Central Bank",
      "status": "active",
      "last_updated": 1711224000,
      "update_frequency_seconds": 86400,
      "currency_count": 33
    }
  ]
}

cURL

curl -H "X-API-Key: er_live_YOUR_KEY" \
  https://api.exchangerate-intel.com/v1/sources

POST/v1/auth/register

Creates a new developer account and issues a free-tier API key.

Request Body

Field	Type	Description
emailrequired	string	Developer email address
passwordrequired	string	Minimum 8 characters

Response

201 Created

{
  "api_key": "er_live_a1b2c3d4e5f6g7h8i9j0k1l2m3n4o5p6",
  "plan": "free",
  "quota": 1000,
  "email": "you@example.com"
}

cURL

curl -X POST \
  -H "Content-Type: application/json" \
  -d '{"email":"you@example.com","password":"yourpassword"}' \
  https://api.exchangerate-intel.com/v1/auth/register

POST/v1/auth/subscribe

Initiates a Stripe checkout session to upgrade your plan. On success, redirect the user to the returned checkout_url.

Request Headers

Header	Description
X-API-Key	Your current API key (required)

Request Body

Field	Type	Description
planrequired	string	One of: `starter`, `growth`, `business`
success_urloptional	string	Redirect URL after successful payment
cancel_urloptional	string	Redirect URL if user cancels

Response

200 OK

{
  "checkout_url": "https://checkout.stripe.com/pay/cs_live_...",
  "session_id": "cs_live_a1b2c3d4e5f6"
}

cURL

curl -X POST \
  -H "X-API-Key: er_live_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"plan":"starter"}' \
  https://api.exchangerate-intel.com/v1/auth/subscribe

Real-Time Exchange Rates

Real-Time Rates

170+ Currencies

Historical Data

Currency Conversion

Time-Series Ranges

Reliable & Secure

Simple, Transparent Pricing

Free

Starter

Growth

Business

Enterprise

Developer Dashboard

Create Account

Your API Key

Introduction

Authentication

Quickstart

Supported Sources

Rate Limits

Error Codes

API Playground

Interactive Request Builder

GET/v1/latest

Query Parameters

Response

GET/v1/historical

Query Parameters

Response

GET/v1/range

Query Parameters

Response

GET/v1/convert

Query Parameters

Response

GET/v1/currencies

Response

GET/v1/sources

Response

POST/v1/auth/register

Request Body

Response

POST/v1/auth/subscribe

Request Headers

Request Body

Response