Get an open-ended time series of exchange rates

Retrieves available working-day exchange-rate observations from a start date through the latest observation. The returned `start_date` can precede the requested calendar date when the range starts on a non-working day, and `end_date` identifies the latest observation available when the response was generated.

Query ECB reference rates, currencies, and historical time series without an API key; this collection covers the still-available v1.

Request

operationId: getOpenEndedTimeSeriesRates
Server: https://api.frankfurter.dev/v1
Authentication: None

Request parameters

`start_date`

pathstringdaterequired

Start date in ISO 8601 format (YYYY-MM-DD)

2026-08-01

`amount`

querynumberdouble

The amount to be converted (default is 1)

`base`

querystring

Base currency code (three-letter ISO 4217 code)

EUR

`symbols`

querystring

Comma-separated list of currency codes to limit the response

Responses

`200`

TimeSeriesResponseapplication/json

Successful response with exchange rates from the requested start through the latest observation

Properties: amountbasestart_dateend_daterates

`404`

Errorapplication/json

No data available for the specified start date

Properties: message

`422`

Errorapplication/json

Unprocessable date or query parameter, for example an invalid calendar date or amount

Properties: message

{
  "amount": 1,
  "base": "EUR",
  "start_date": "2026-07-31",
  "end_date": "2026-08-07",
  "rates": {
    "2026-07-31": {
      "USD": 1.1485
    },
    "2026-08-03": {
      "USD": 1.1535
    },
    "2026-08-07": {
      "USD": 1.1535
    }
  }
}