Fiat Currency Trading with Stablecoin Settlement

Use SpherePay to facilitate currency trading between fiat pairs using stablecoins as the settlement layer. The pattern is the same across corridors — a stablecoin sandwich routes the trade through USDC (or another stablecoin), with SpherePay handling both fiat legs. This is the right pattern for FX brokerages, currency-exchange platforms, B2B cross-currency settlement, and any product that needs to convert one fiat into another fast and predictably.

The pattern, in one shape

Every corridor below follows the same three-step model:

On-ramp the source fiat to USDC.
Bridge the USDC across networks if needed (one wallet to another).
Off-ramp USDC to the destination fiat.

The cleanest implementation uses an Offloader Wallet for step 3 — Sphere automatically converts USDC to the destination fiat and wires it to a bank account, eliminating the need for a second transfer API call.

Both fiat legs require separate verification profiles on the customer (one per currency). See each corridor below for the specific profiles required.

Supported corridors

Expand a corridor below for the full step-by-step integration walkthrough.

BRL ↔ USD — Brazilian Real and US Dollar

The most common Sphere corridor today. Moves funds between Brazilian Reais (via PIX) and US Dollars (via wire or ACH) with USDC as the bridge currency.Common use cases:

Import/export payments — Brazilian importers paying USD invoices to international suppliers, or exporters receiving USD proceeds.
Loan repayments — borrowers holding BRL servicing USD-denominated debt.
Real estate transactions — buyers or sellers in Brazilian property deals settling in USD.
Remittances — Brazilian senders, US recipients.

Prerequisites

The customer must be approved for both verification profiles:

kyc_profile_a / kyb_profile_a — required for USD transfers
kyc_profile_b / kyb_profile_b — required for BRL/PIX transfers

See Individual KYC and Business KYB for setup.

Passing "network": "sol" on a BRL transfer will result in a rejected request. Use ethereum, polygon, arbitrum, base, or avalanche for USDC. USDT supports ethereum or tron.

Flow

Step 1 — Create a USD bank account

POST https://api.spherepay.co/v2/bank-account

{
  "customerId": "{{customer_id}}",
  "bankName": "Chase",
  "accountName": "My USD Account",
  "accountOwner": "Alice Johnson",
  "currency": "usd",
  "accountDetails": {
    "accountNumber": "1234567890",
    "routingNumber": "021000021",
    "accountType": "checking"
  },
  "networks": ["wire"]
}

Step 2 — Create an Offloader Wallet

POST https://api.spherepay.co/v2/offloader-wallet

{
  "customerId": "{{customer_id}}",
  "currency": "usdc",
  "network": "polygon",
  "destination": {
    "bankAccountId": "{{usd_bank_account_id}}",
    "currency": "usd",
    "network": "wire"
  }
}

Store the returned address as {{offloader_address}}.

Step 3 — Register the Offloader address as a wallet

POST https://api.spherepay.co/v2/wallet

{
  "customerId": "{{customer_id}}",
  "network": "polygon",
  "address": "{{offloader_address}}"
}

Store the returned id as {{wallet_id}}. Steps 1–3 only need to be done once per customer — reuse {{wallet_id}} for all future BRL → USD transfers.

Step 4 — Create a BRL bank account

POST https://api.spherepay.co/v2/bank-account

{
  "currency": "brl",
  "bankName": "Banco do Brasil",
  "accountName": "My BRL Account",
  "accountDetails": {
    "pixKey": "alice@example.com",
    "pixKeyType": "email"
  },
  "accountOwner": {
    "accountHolderName": "Alice Johnson",
    "address": {
      "line1": "Rua das Flores 123",
      "city": "São Paulo",
      "state": "SP",
      "postalCode": "01310-100",
      "country": "BRA"
    }
  },
  "networks": ["pix"]
}

pixKeyType accepts email, phone, cnpj, or random.

Step 5 — Create the BRL → USDC transfer

POST https://api.spherepay.co/v2/transfer

{
  "customer": "{{customer_id}}",
  "amount": "100.00",
  "source": {
    "type": "bank_account",
    "id": "{{brl_bank_account_id}}",
    "currency": "brl",
    "network": "pix"
  },
  "destination": {
    "type": "wallet",
    "id": "{{wallet_id}}",
    "currency": "usdc",
    "network": "polygon"
  },
  "integratorBpsFeeRate": "50"
}

BRL constraints: integratorBpsFeeRate is required (fixed fees not supported), per-transfer limits R

1.00–R

7,500.00, Solana not supported. See Supported rails.

Step 6 — Fund the transaction

The response includes an instructions.pixKey — present this to your end user. Once they send the BRL via PIX:

Sphere receives the BRL and converts it to USDC.
USDC is delivered to the Offloader Wallet.
The Offloader Wallet auto-converts USDC to USD and wires it to the registered USD bank account.

Reverse direction — USD → BRL

For the opposite direction, flip the pattern: register a BRL Offloader Wallet (USDC → BRL via PIX), then on-ramp USD → USDC into it. Same primitives, same number of API calls.

Error handling

Scenario	What happens	What to do
On-ramp fails	BRL returned via PIX. No USDC minted.	Retry or surface to user.
On-ramp succeeds, Offloader conversion fails	USDC sits in Offloader Wallet. No USD sent.	Contact SpherePay support.
Customer sends wrong PIX amount	Partial or excess USDC lands in Offloader Wallet.	Wallet converts whatever arrives — reconcile on your side.

USD ↔ EUR — US Dollar and Euro

Convert between US Dollars (via ACH or wire) and Euros (via SEPA) with USDC or EURC as the bridge. SEPA settles same/next business day; SEPA Instant is near-instant where supported.Common use cases:

US importers paying European suppliers.
European platforms accepting USD revenue and settling to EUR.
Cross-border treasury — companies operating in both regions managing FX exposure.
FX brokerages offering retail USD/EUR conversion.

Prerequisites

The customer must be approved for both USD and EUR verification profiles. Both fiat rails fall under kyc_profile_a / kyb_profile_a (no separate profile is needed for EUR, unlike BRL).All standard USDC networks are supported, including Solana. For EURC, supported networks are Base, Ethereum, and Solana.

Flow

Step 1 — Create an EUR bank account

POST https://api.spherepay.co/v2/bank-account

{
  "customerId": "{{customer_id}}",
  "bankName": "Deutsche Bank",
  "accountName": "EUR settlement",
  "accountOwner": "Acme GmbH",
  "currency": "eur",
  "accountDetails": {
    "iban": "DE89370400440532013000",
    "bic": "DEUTDEFFXXX"
  },
  "networks": ["sepa"]
}

Use sepaInstant in networks if you need near-instant settlement and the recipient bank supports it.

Step 2 — Create an Offloader Wallet for USDC → EUR

POST https://api.spherepay.co/v2/offloader-wallet

{
  "customerId": "{{customer_id}}",
  "currency": "usdc",
  "network": "ethereum",
  "destination": {
    "bankAccountId": "{{eur_bank_account_id}}",
    "currency": "eur",
    "network": "sepa"
  }
}

Pick the source network based on where you’ll be receiving USDC. Solana is the cheapest and fastest; Ethereum and Base are common for institutional flows.Store the returned address as {{offloader_address}}.

Step 3 — Register the Offloader address as a wallet

POST https://api.spherepay.co/v2/wallet

{
  "customerId": "{{customer_id}}",
  "network": "ethereum",
  "address": "{{offloader_address}}"
}

Store the returned id as {{wallet_id}}.

Step 4 — Create a USD bank account

POST https://api.spherepay.co/v2/bank-account

{
  "customerId": "{{customer_id}}",
  "bankName": "Chase",
  "accountName": "USD source",
  "accountOwner": "Acme Inc",
  "currency": "usd",
  "accountDetails": {
    "accountNumber": "1234567890",
    "routingNumber": "021000021",
    "accountType": "checking"
  },
  "networks": ["ach", "wire"]
}

Step 5 — Create the USD → USDC transfer

POST https://api.spherepay.co/v2/transfer

{
  "customer": "{{customer_id}}",
  "amount": "10000.00",
  "source": {
    "type": "bank_account",
    "id": "{{usd_bank_account_id}}",
    "currency": "usd",
    "network": "wire"
  },
  "destination": {
    "type": "wallet",
    "id": "{{wallet_id}}",
    "currency": "usdc",
    "network": "ethereum"
  }
}

Pick wire for same-day settlement, ach for cheaper but slower (1–2 business days).

Step 6 — Settlement

Once USD arrives at SpherePay:

Sphere converts USD → USDC.
USDC is delivered to the Offloader Wallet.
Offloader Wallet auto-converts USDC → EUR and sends via SEPA.

Total time: minutes (wire) to ~1 business day (ACH + SEPA), depending on rail choices.

Reverse direction — EUR → USD

Same primitives, flipped. Register a USD Offloader Wallet (USDC → USD), on-ramp EUR → USDC into it.

Using EURC instead of USDC

For EUR-heavy flows, EURC can reduce slippage. Set currency: "eurc" and network to one of base, ethereum, or solana on the Offloader Wallet. The bridge currency becomes EURC instead of USDC; the rest of the integration is identical.

What you handle vs. what SpherePay handles

Responsibility	Owner
Creating the customer, bank accounts, and wallet objects	You (integrator)
Creating and managing the Offloader Wallet	You (integrator)
Initiating the on-ramp transfer	You (integrator)
Fiat collection and source-fiat → USDC conversion	SpherePay
USDC → destination-fiat conversion and settlement	SpherePay (via Offloader Wallet)
Handling failures on either leg	You (integrator)

Constraints common to all corridors

Each leg is billed as a separate transfer.
Offloader Wallets don’t support webhooks today — poll GET /v2/transfer/{id} to track on-ramp status.
Both source-fiat and destination-fiat verification profiles must be approved before either transfer can be initiated.

Looking ahead — single-call cross-currency transfers

Today every corridor requires setting up an Offloader Wallet plus a separate on-ramp transfer call. SpherePay is working toward a single-call cross-currency transfer API that abstracts the stablecoin hop entirely — you’d send one request with the source and destination currencies, and SpherePay would handle the routing internally. When that ships, the patterns in this guide will still work, but you’ll have the option to consolidate to a single call.

Offloader Wallets

How automated stablecoin-to-fiat conversion works.

Transfers API

Full transfer creation and tracking reference.

Supported rails

Per-currency network and rail compatibility.

Cross-border trade finance

Multi-party trade payment patterns.

Overview

Money movement

Fiat Currency Trading with Stablecoin Settlement

The pattern, in one shape

Supported corridors

Prerequisites

Flow

Step 1 — Create a USD bank account

Step 2 — Create an Offloader Wallet

Step 3 — Register the Offloader address as a wallet

Step 4 — Create a BRL bank account

Step 5 — Create the BRL → USDC transfer

Step 6 — Fund the transaction

Reverse direction — USD → BRL

Error handling

Prerequisites

Flow

Step 1 — Create an EUR bank account

Step 2 — Create an Offloader Wallet for USDC → EUR

Step 3 — Register the Offloader address as a wallet

Step 4 — Create a USD bank account

Step 5 — Create the USD → USDC transfer

Step 6 — Settlement

Reverse direction — EUR → USD

Using EURC instead of USDC

What you handle vs. what SpherePay handles

Constraints common to all corridors

Looking ahead — single-call cross-currency transfers

Offloader Wallets

Transfers API

Supported rails

Cross-border trade finance

Overview

Money movement

Documentation Index

​The pattern, in one shape

​Supported corridors

​Prerequisites

​Flow

​Step 1 — Create a USD bank account

​Step 2 — Create an Offloader Wallet

​Step 3 — Register the Offloader address as a wallet

​Step 4 — Create a BRL bank account

​Step 5 — Create the BRL → USDC transfer

​Step 6 — Fund the transaction

​Reverse direction — USD → BRL

​Error handling

​Prerequisites

​Flow

​Step 1 — Create an EUR bank account

​Step 2 — Create an Offloader Wallet for USDC → EUR

​Step 3 — Register the Offloader address as a wallet

​Step 4 — Create a USD bank account

​Step 5 — Create the USD → USDC transfer

​Step 6 — Settlement

​Reverse direction — EUR → USD

​Using EURC instead of USDC

​What you handle vs. what SpherePay handles

​Constraints common to all corridors

​Looking ahead — single-call cross-currency transfers

​Related

Offloader Wallets

Transfers API

Supported rails

Cross-border trade finance

The pattern, in one shape

Supported corridors

Prerequisites

Flow

Step 1 — Create a USD bank account

Step 2 — Create an Offloader Wallet

Step 3 — Register the Offloader address as a wallet

Step 4 — Create a BRL bank account

Step 5 — Create the BRL → USDC transfer

Step 6 — Fund the transaction

Reverse direction — USD → BRL

Error handling

Prerequisites

Flow

Step 1 — Create an EUR bank account

Step 2 — Create an Offloader Wallet for USDC → EUR

Step 3 — Register the Offloader address as a wallet

Step 4 — Create a USD bank account

Step 5 — Create the USD → USDC transfer

Step 6 — Settlement

Reverse direction — EUR → USD

Using EURC instead of USDC

What you handle vs. what SpherePay handles

Constraints common to all corridors

Looking ahead — single-call cross-currency transfers

Related