Exchange

The Exchange APIs allow you to convert between currencies. There are two mechanisms depending on whether you want to convert within your own wallets or send directly to an external beneficiary.

Exchange Methods

Method	Description	Wallet Balance Required	Beneficiary Required	Payment Instructions
Swap	Convert between currencies within your own wallets	Yes	No	No
Direct Exchange	Convert and send to an external beneficiary in one step	No	Yes	Yes
Crypto offramp	Convert stablecoin (USDC/USDT) to fiat and pay a bank account	No	Yes	Yes (crypto address)

Swap vs Direct Exchange

Swap

A Swap converts funds between different currencies within your own wallets. For example, converting USD in your USD wallet to EUR in your EUR wallet.

Requires wallet balance in the source currency
No external beneficiary — funds stay in your wallets
Conversion happens immediately upon quote acceptance
Uses quote_type: "SWAP"

Direct Exchange

A Direct Exchange converts funds and sends them directly to an external beneficiary without requiring a wallet balance. You receive payment instructions after accepting the quote, send the funds, and the payout is delivered to the beneficiary.

No wallet balance required — you deposit funds after accepting the quote
External beneficiary required — funds are sent to the recipient
Payment instructions provided after quote acceptance
Uses quote_type: "DIRECT_EXCHANGE"

Crypto offramp

A Crypto offramp is a Direct Exchange where the source is stablecoin (USDC or USDT) and the target is fiat (GBP, EUR, CAD bank transfer, when enabled on your account). Sznd maps a crypto deposit address to the fiat beneficiary. Each accept returns that address with the amount and 15-minute funding deadline for that transaction; Sznd converts and pays the beneficiary bank account.

Customer must be registered and verified (on_behalf_of)
Fiat beneficiary required — crypto address is mapped to that bank account
Amount and funding deadline are per accept; the address typically persists for the same beneficiary
See the full guide: Crypto offramp

Common Flow

Both methods use the Quotes API:

Create a Quote — POST /api/v1/client/quotes with the appropriate quote_type
Accept the Quote — POST /api/v1/client/quotes/{id}/accept
Process — For Swap, conversion is immediate. For Direct Exchange, follow the payment instructions.
Webhook — Receive a transaction webhook on completion.

Authentication

All exchange endpoints require HMAC authentication:

For details, see the Authentication documentation.

Prerequisites

origin_reference — Unique transaction ID for idempotency (required for all business API requests)
on_behalf_of — Required for business API: "self" for the business owner's account, or a customer user ID (see Quotes API)
Beneficiary — Required for Direct Exchange only. Create via Beneficiaries API.

Next Steps

Swap — Convert between currencies within your wallets
Direct Exchange — Convert and send to an external beneficiary
Crypto offramp — Stablecoin to fiat with a Sznd-mapped crypto deposit address
Quotes API — Full quote API reference
Exchange Rates — Preview rates before creating a quote