Any time fromCurrency and toCurrency differ on a collection or payout, you need a rateKey. Get one from the quote endpoint.
Response
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string
required
Currency you’re converting from.
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string
required
Currency you’re converting to.
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number
required
Amount in fromCurrency units to price.
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string
Optionally pin the quote to a specific rail: ach, iban, swift, wire, pix, ethereum, bridge_wallet, or nip. Different rails can carry different fees and rates.

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Using the rateKey

rateKey is an encoded, time-limited token that captures the rate, currency pair, and fee at the moment of the quote. Pass it straight through as rateKey on:
  • POST /api/deposit — to convert on collection.
  • POST /api/payout — required whenever fromCurrency !== toCurrency.
Quotes expire. If you hold a rateKey too long before using it, the downstream request will fail — re-fetch a fresh quote right before you submit the collection or payout.

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Reading the response

  • rate — the raw exchange rate.
  • roundedRate — the display-friendly rounded rate; show this to customers.
  • fee — the fee charged for the conversion, in fromCurrency units.
  • toAmount — what the customer receives/what gets paid out, in toCurrency units.
  • totalAmount — amount + fee, in fromCurrency units — what actually gets debited.

Full endpoint reference

See the complete schema and error cases.