frankfurter.timeseries

stable Advanced

ECB rates over a date range (rates keyed by date).

GET /v1/frankfurter/timeseries

What you get#

One Frankfurter record in Onekey's unified shape, in data. If the record does not exist you get a 404 not_found and are not charged.

What it costs#

Advanced · 5 credits for a fresh fetch, charged only when it succeeds.
Free when served from cache (0.2 credit for a cached response over 100 KB).
Free if the request is invalid (never charged) or the source fails or reports not found (refunded).

Parameters#

Name	Type	Required	Default	What it is	Constraints
`start`	string	yes	(required)	Start date YYYY-MM-DD	max 10 chars; must match `\d{4}-\d{2}-\d{2}`; trimmed
`end`	string	yes	(required)	End date YYYY-MM-DD	max 10 chars; must match `\d{4}-\d{2}-\d{2}`; trimmed
`base`	string	no	`eur`	Base currency (ISO 4217), e.g. usd	max 3 chars; must match `[A-Za-z]{3}`; trimmed, lowercased
`symbols`	string	no	`usd,eur,gbp,jpy`	Comma-separated target currencies	max 39 chars; must match `[A-Za-z]{3}(?:,[A-Za-z]{3}){0,9}`; trimmed, lowercased

Request#

curl "https://api.onekey.dev/v1/frankfurter/timeseries?start=2024-01-01&end=2024-01-10&base=usd" \
  -H "x-api-key: YOUR_API_KEY"

Try it

Add your key to run this call right here. No key? Get one free. The key stays in this tab.

Recorded response#

A real Frankfurter response, recorded and returned in Onekey's shape. Fields the platform does not provide are null.

json

{
  "success": true,
  "data": {
    "market": {
      "symbol": "USD"
    },
    "entity": {
      "createdAt": "2023-12-29T00:00:00Z",
      "date": "2024-01-10T00:00:00Z"
    },
    "ext": {
      "rates": {
        "2023-12-29": {
          "EUR": 0.90498,
          "GBP": 0.78647,
          "JPY": 141.48
        },
        "2024-01-02": {
          "EUR": 0.91274,
          "GBP": 0.79085,
          "JPY": 142.1
        },
        "2024-01-03": {
          "EUR": 0.91583,
          "GBP": 0.79192,
          "JPY": 143.02
        },
        "2024-01-04": {
          "EUR": 0.91299,
          "GBP": 0.78771,
          "JPY": 144.17
        },
        "2024-01-05": {
          "EUR": 0.91567,
          "GBP": 0.7894,
          "JPY": 145.2
        },
        "2024-01-08": {
          "EUR": 0.91358,
          "GBP": 0.78705,
          "JPY": 144.52
        },
        "2024-01-09": {
          "EUR": 0.91408,
          "GBP": 0.78554,
          "JPY": 144.09
        },
        "2024-01-10": {
          "EUR": 0.91358,
          "GBP": 0.78589,
          "JPY": 145.29
        }
      }
    }
  },
  "metadata": {
    "platform": "frankfurter",
    "endpoint": "timeseries",
    "cached": false,
    "stale": false,
    "age_s": 0,
    "fetched_at": "2026-01-01T12:00:00+00:00",
    "credits_charged": 5,
    "request_id": "7f3a9c2e5b1d4c8fa2e6d0b9c4f18e37"
  },
  "error": null
}

Field mapping#

How this endpoint's source fields become Onekey's unified schema. Fields the source lacks come back as null.

Source path	Onekey field	Transform
`base`	`market.symbol`	-
`start_date`	`entity.createdAt`	`toIsoDate`
`end_date`	`entity.date`	`toIsoDate`
`rates`	`ext.rates`	-

Caching and freshness#

Fresh for about 1 hour. Repeat calls in that window are served from cache and are free.
Between 1 hour and 1 day the cached copy is still served instantly and marked stale: true while Onekey refreshes it in the background.
If the source is down when a refresh is needed, the last copy can be served for up to 1 day more (marked stale).
A "not found" is remembered for 5 minutes and is free.
The cache is shared across all customers, which is what keeps repeat calls cheap.

What can go wrong#

Status	Code	What to do
401	`unauthorized`	Check the `x-api-key` header.
402	`insufficient_credits`	Add credits; your balance must cover the price.
404	`not_found`	That record does not exist. Free; do not retry.
422	`invalid_params`	Fix the parameters using the table above. Free.
429	`rate_limited`	Wait `Retry-After` seconds, then retry.
502	`upstream_error`	The source failed. Refunded; retry with backoff.

See Errors for the full list and retry guidance.

Status: stable (verified against the live source).