Function getCurrencyRate

getCurrencyRate(from: valueof, to: valueof): Promise<number>

Fetches the current exchange rate between two currencies. Uses the Hexarate API to get real-time exchange rates. Implements caching using LRU cache to minimize API calls.

Parameters

from: valueof
The source currency code (e.g., 'USD', 'EUR')
to: valueof
The target currency code

Returns Promise<number>

The exchange rate as a number

Throws

Error if the API request fails or rate cannot be fetched

Example

// Get EUR to USD rate
const rate = await getCurrencyRate('EUR', 'USD')
// Returns something like 1.18 (meaning 1 EUR = 1.18 USD)

// Convert amount using rate
const amount = 100;
const converted = amount * rate; // 118 USD

// Rates are cached for subsequent calls
await getCurrencyRate('EUR', 'USD') // Uses cached value

Source

export async function getCurrencyRate(from: CurrencyCode, to: CurrencyCode): Promise<number> {
  try {
    return await lruCurrencyRate.fetch(`${from}:${to}`);
  } catch (error) {
    throw new Error(
      `Failed to get currency rate for ${from} to ${to} - ${error instanceof Error ? error.message : String(error)}`,
    );
  }
}