FX Rates

Get foreign exchange rates between fiat currencies.

GET/v1/fx/rate

Parameters

Parameter	Type	Description
from*	string	Source currency code (e.g., EUR)
to*	string	Target currency code (e.g., USD)
dateoptional	YYYY-MM-DD	Historical date. Omit for latest.

Request

curl "https://api.cryptachain.com/v1/fx/rate?from=EUR&to=USD&date=2026-04-04" \
  -H "X-API-Key: $CRYPTACHAIN_API_KEY"

Response

Response 200 OK

{
  "from": "EUR",
  "to": "USD",
  "rate": 1.0870,
  "date": "2026-04-04",
  "source": "ecb"
}

Rate convention

Rates follow the "1 foreign = X USD" convention for USD-based pairs, and "1 base = X quote" for cross pairs. This is the standard accounting convention.

Historical FX rates

GET/v1/fx/history

curl "https://api.cryptachain.com/v1/fx/history?from=EUR&to=USD&startDate=2026-01-01&endDate=2026-03-31" \
  -H "X-API-Key: $CRYPTACHAIN_API_KEY"

Weekend and holiday handling

ECB does not publish rates on weekends and public holidays. CryptaChain fills gaps by carrying forward the last known rate:

• Saturday/Sunday: Friday's rate is used
• Public holidays: Previous business day's rate
• BGN: Always 1.95583 per EUR (currency board peg since 1999)
• AED, SAR, QAR, OMR, BHD: Fixed USD pegs, constant rates