Sphere Blog
2 min

Onramper Account API

USD and EUR virtual accounts with automatic fiat-to-stablecoin conversion.

Written by
Sphere Team
Published on
September 10, 2025

Onramper Account API: Native USD and EUR Virtual Accounts for Stablecoins

We’re excited to announce the launch of SpherePay’s Onramper Account API, an API-first solution that provides native USD and EUR virtual accounts for stablecoin wallets.

Designed for crypto-native businesses, fintechs, and developers, the Onramper Account API removes the complexity of fiat-to-crypto workflows by automatically converting incoming fiat deposits into stablecoins. With a single integration, businesses can offer seamless, programmable fiat onramps without relying on exchanges or manual conversion flows.

The Problem We’re Solving

Traditional crypto onboarding has been a friction-heavy process. Users typically need to:

  • Navigate complex exchange interfaces
  • Manually initiate fiat-to-crypto conversions
  • Wait through multiple confirmation steps
  • Deal with inconsistent settlement times and opaque fees

For businesses building crypto-enabled products, this friction directly translates to higher drop-off, lower conversion, and increased operational overhead.

Onramper Accounts change that equation by abstracting away these steps entirely.

Automated Fiat-to-Stablecoin Infrastructure

Onramper Accounts provide each end user with a dedicated virtual bank account that is programmatically linked to a specific wallet address.

When fiat funds arrive, they are automatically converted into the specified stablecoin and delivered onchain, with no manual intervention required.

How it works:

  • Create an Onramper Account via the API
  • Receive unique banking details (account number, routing number, etc.)
  • End users deposit fiat via standard bank transfers
  • Conversion happens automatically upon deposit
  • Stablecoins are delivered directly to the linked wallet

This enables a fully automated, end-to-end fiat-to-stablecoin flow.

Supported Currencies, Stablecoins, and Networks

Supported Fiat Currencies

  • USD
  • EUR

Supported Stablecoins & Networks

  • USDC on Arbitrum, Avalanche, Base, Ethereum, Polygon, and Solana
  • USDT on Ethereum and Tron

This multi-chain support ensures businesses can serve users across ecosystems without fragmentation.

Built for Global Scale

Onramper Accounts are available to end users globally, excluding sanctioned regions. Businesses can support international customers without managing separate regional banking integrations or onramp providers.

Whether you’re building a DeFi protocol, payments platform, marketplace, or embedded crypto experience, Onramper Accounts enable global fiat access through a single API.

Developer-First API Design

The Onramper Account API is designed for full programmatic control across the account lifecycle.

Create a Virtual Account

POST /v2/virtualAccount

{
 "customerId": "customer_1ab2c3d4",
 "sourceCurrency": "USD",
 "destinationCurrency": "USDC",
 "network": "ethereum",
 "walletAddress": "0x1234...abcd"
}

Example API Response

{
 "id": "virtualAccount_987xyz654",
 "active": true,
 "fees": {
   "totalBpsRate": "20",
   "integratorFee": { "bpsRate": "10" },
   "platformFee": { "bpsRate": "10" }
 },
 "depositInstructions": {
   "currency": "USD",
   "bankName": "Bank of Example",
   "bankAccountNumber": "000123456789",
   "bankRoutingNumber": "1234567890",
   "bankBeneficiaryName": "John Doe",
   "bankBeneficiaryAddress": "123 Main St, Anytown, USA"
 },
 "destination": {
   "currency": "USDC",
   "walletAddress": "0x1234...abcd",
   "network": "ethereum"
 },
 "created": "2025-04-20T21:49:46.697Z",
 "updated": "2025-04-20T21:50:18.854Z"
}

Complete Account Lifecycle Management

Beyond account creation, the API supports full lifecycle management:

  • Retrieve account details and status
  • Update account configurations
  • List accounts by customer
  • Deactivate and reactivate accounts programmatically

This allows teams to manage users and funds at scale without operational bottlenecks.

Built-In Verification Support

Onramper Accounts support standard financial verification methods, including micro-deposits and challenge deposits. This makes it easy for users to connect accounts from payroll providers, fintech apps, and other financial platforms.

Enterprise-Grade Security and Compliance

Security and compliance are foundational to Onramper Accounts:

  • Comprehensive KYC and KYB verification
  • SOC 2–aligned security practices
  • Ongoing AML monitoring
  • Regulatory compliance across supported jurisdictions

The infrastructure is designed to meet the needs of regulated, production-grade financial applications.

Getting Started

To integrate Onramper Accounts, you’ll need:

  • An active SpherePay merchant account with completed KYC
  • Customer registration via the Customer API
  • API integration using our developer documentation

Onramper Accounts are available in both sandbox and production environments, with full documentation and examples to support implementation.

Looking Ahead

This is the foundation of a broader roadmap. We’re continuing to expand Onramper Accounts with additional currencies, enhanced controls, and deeper developer tooling.

Our goal is simple: make stablecoin payments as seamless and reliable as traditional payments.

Start Building Today

Onramper Accounts represent a fundamental shift in how businesses can integrate fiat and stablecoins. By eliminating manual conversions and fragmented user flows, teams can offer faster, simpler, and more scalable crypto experiences.

Ready to get started?
Explore the Onramper Accounts API documentation or contact our team to learn more about pricing and integration support.

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