FX rates
Reference rates and conversion mechanics for multi-currency ledgers.
An FX rate is the exchange rate Core uses to convert between currencies inside the ledger. If your product holds balances in more than one currency — for example, COP and USD — every cross-currency operation needs a rate to compute the equivalent amount in the destination currency. Core publishes reference rates at a fixed cadence and applies them to internal conversions on your ledger.
You will care about FX rates if you build a multi-currency wallet, a treasury product, or any case where money moves between accounts that use different ISO 4217 currencies.
What it is
An FX rate is a tuple (base_currency, quote_currency, rate, valid_from, valid_until). Core stores the active rates and applies them automatically when you perform a cross-currency ledger operation.
When it is applied
- A cross-currency ledger transaction (e.g., debit USD account, credit COP account).
- A cross-currency payout.
- A cross-currency authorization on a card spending against an account in a different currency than the merchant.
Rounding and fees
Converted amounts are rounded to the decimals of each currency. On transfers between subaccounts, your spread over the reference rate and a fixed conversion charge are fees you price with your fee policies — see Transfers between subaccounts and Fee policies.
Data model
The full schema lives in the Core FX rates API reference.