Fluctuation

Returns, for every requested currency, its rate at the end of date_from and of date_to (UTC) and how much it changed in between, in absolute terms and in percent. One request replaces two historical lookups and the arithmetic.

Request Method: GET
Request URL: https://api.fxapi.com/v1/fluctuation

Request Parameters

Parameter	Type	Mandatory	Description
apikey	string	️	Your API Key
date_from	string	️	First day, format YYYY-MM-DD, 1999-01-01 or later
date_to	string	️	Last day, format YYYY-MM-DD, on or after date_from and yesterday at the latest
base_currency	string		The base currency all rates are expressed in Default: USD
currencies	string		A list of comma-separated currency codes (EUR,GBP,JPY) By default all currencies are returned
type	string		Filter by type: fiat, metal, crypto
format	string		json (default) or csv (date_from,date_to,base_currency,currency,start_rate,end_rate,change,change_pct)

A request costs one request of your quota. If no rates are stored for one of the two days, the endpoint returns a 404.

Sample Request

curl -G https://api.fxapi.com/v1/fluctuation \
    -d date_from=2026-01-01 \
    -d date_to=2026-06-30 \
    -d currencies=EUR,GBP \
    -H "apikey: YOUR-API-KEY"

Sample Response

change is end_rate - start_rate; change_pct is the change in percent of start_rate, rounded to 4 decimals.

{
    "meta": {
        "base_currency": "USD",
        "date_from": "2026-01-01",
        "date_to": "2026-06-30"
    },
    "data": {
        "EUR": {
            "code": "EUR",
            "start_rate": 0.9654,
            "end_rate": 0.8771,
            "change": -0.0883,
            "change_pct": -9.1465
        },
        "GBP": {
            "code": "GBP",
            "start_rate": 0.7988,
            "end_rate": 0.7302,
            "change": -0.0686,
            "change_pct": -8.5879
        }
    }
}