# Frankfurter on Onekey

> 4 endpoints for Frankfurter (4 stable, 0 beta), 1 to 5 credits each. Category: Finance & markets. One key, one JSON shape.

Base URL: https://api.onekey.dev
Auth: header `x-api-key: <key>`. Call shape: `GET /v1/{platform}/{endpoint}?{params}`.
Every response is `{success, data, metadata, error}`; check `success` first. Cost is in `metadata.credits_charged`. Free when served from cache (0.2 credit for a cached response over 100 KB). Failed and not-found calls are refunded.
Status: stable = verified against the live source; beta = not yet verified, fields may be missing.

Page: https://onekey.dev/platforms/frankfurter
Reference (Markdown): https://onekey.dev/docs/api/frankfurter.md
All docs: https://onekey.dev/llms.txt

## Canonical fields returned

Unified-schema fields (same names on every platform), with how many of the 4 mapped Frankfurter endpoints return each:

- `entity.date` (ISO 8601 date): 3
- `market.symbol` (string): 3
- `entity.createdAt` (ISO 8601 date): 1
- plus 3 platform-specific fields under `ext.`

## Endpoints

### frankfurter.currencies

Currencies supported by the ECB feed (code -> name).
- Price: 1 credit per fresh call. Status: stable. Returns: one record.
- Request: `GET https://api.onekey.dev/v1/frankfurter/currencies` with header `x-api-key: YOUR_API_KEY`
- Parameters: none
- Fields returned: `ext.currencies`
- Reference: https://onekey.dev/docs/api/frankfurter/currencies.md

### frankfurter.historical

ECB reference rates on a past date.
- Price: 1 credit per fresh call. Status: stable. Returns: one record.
- Request: `GET https://api.onekey.dev/v1/frankfurter/historical?date=2024-01-02&base=usd` with header `x-api-key: YOUR_API_KEY`
- Parameters:
  - `date` (string, required): Date YYYY-MM-DD
  - `base` (string, optional, default eur): Base currency (ISO 4217), e.g. usd
- Fields returned: `market.symbol`, `entity.date`, `ext.amount`, `ext.rates`
- Reference: https://onekey.dev/docs/api/frankfurter/historical.md

### frankfurter.latest

Latest ECB reference rates for a base currency.
- Price: 1 credit per fresh call. Status: stable. Returns: one record.
- Request: `GET https://api.onekey.dev/v1/frankfurter/latest?base=usd` with header `x-api-key: YOUR_API_KEY`
- Parameters:
  - `base` (string, optional, default eur): Base currency (ISO 4217), e.g. usd
- Fields returned: `market.symbol`, `entity.date`, `ext.amount`, `ext.rates`
- Reference: https://onekey.dev/docs/api/frankfurter/latest.md

### frankfurter.timeseries

ECB rates over a date range (rates keyed by date).
- Price: 5 credits per fresh call. Status: stable. Returns: one record.
- Request: `GET https://api.onekey.dev/v1/frankfurter/timeseries?start=2024-01-01&end=2024-01-10&base=usd` with header `x-api-key: YOUR_API_KEY`
- Parameters:
  - `start` (string, required): Start date YYYY-MM-DD
  - `end` (string, required): End date YYYY-MM-DD
  - `base` (string, optional, default eur): Base currency (ISO 4217), e.g. usd
  - `symbols` (string, optional, default usd,eur,gbp,jpy): Comma-separated target currencies
- Fields returned: `market.symbol`, `entity.createdAt`, `entity.date`, `ext.rates`
- Reference: https://onekey.dev/docs/api/frankfurter/timeseries.md

## Sample request

```bash
curl "https://api.onekey.dev/v1/frankfurter/currencies" \
  -H "x-api-key: YOUR_API_KEY"
```