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How Wirex Pay Works

Overview

Wirex Pay combines blockchain technology with traditional payment infrastructure to enable seamless card transactions powered by on-chain digital assets. Our solution bridges the gap between cryptocurrency holdings and everyday spending, allowing users to make purchases at any merchant that accepts card payments while maintaining full custody of their digital assets until the moment of transaction.

Core Architecture

Smart Wallet Foundation

At the heart of Wirex Pay is an Account Abstraction (AA) wallet - a programmable smart contract wallet that provides enhanced security and flexibility compared to traditional wallets. Each user's AA wallet is deployed using ZeroDev technology and serves as their personal financial control center on the blockchain.

sequenceDiagram
    autonumber
    participant U as User
    participant A as Account Abstraction
    participant I as WP on-chain
    participant B as WP BE
    participant 3 as External wallets

    U->>U: Create a embedded wallet
    U->>A: Create a AA wallet
    U->>A: Instal modules to AA
    A->>I: Register at System, allow debit trx to Buffer
    B-->>A: Start track off-chain balance projection
    B->>A: Can initiate a charge for card or bank transfer trx w/o delay
    A-->>3: Can initiate a transfer
    A->>A: Delay from ExecutorDelay
    A->>B: Update projection balance
    A->>3: Confirm and complete transfer after delay

The AA wallet architecture includes:

  • Embedded Wallet Creation: Users start by creating an embedded wallet that serves as their identity foundation
  • Account Abstraction Deployment: The AA wallet is then deployed on-chain, providing advanced transaction capabilities
  • Modular Security: Custom modules are installed to enable specific functionality while maintaining robust security controls

Security Modules

Wirex Pay implements two critical security modules that work together to protect user funds while enabling seamless transactions:

Execution Delay Policy: This validation module introduces a time-lock mechanism for user-initiated fund transfers. When a user attempts to move funds out of their wallet, a mandatory delay period is enforced. This delay serves as a critical fraud prevention measure, ensuring that users cannot front-run or reverse transactions after a card charge has been initiated. Think of it as a settlement period that protects the integrity of the payment system.

Funds Management Executor: This executor module grants Wirex Pay the specific, limited permission to execute charge operations on behalf of users for off-chain payment activities. This is what enables instant card transactions - when you swipe your card, Wirex Pay can immediately secure the required funds from your AA wallet without requiring manual approval for each transaction. The module only allows debits related to authorized card transactions and withdrawals, maintaining strict boundaries on platform access to user funds.

Balance Management

Wirex Pay maintains a sophisticated balance projection system that tracks both on-chain and off-chain activity in real-time. The platform continuously monitors your AA wallet balance while also accounting for pending card transactions and transfers. This dual-layer tracking ensures that your available balance is always accurate, preventing overdrafts and enabling instant spending authorization.

Unified Balance Architecture

One of the most powerful aspects of Wirex Pay is how it treats your Account Abstraction wallet balance as a single, unified source of funds that powers multiple payment methods simultaneously.

One Balance, Multiple Payment Methods

Your AA wallet balance isn't just for cryptocurrency transactions - it becomes the central liquidity pool that enables various traditional payment methods:

Card Payments: Your Wirex Pay card draws directly from your AA balance for purchases at any merchant worldwide. Whether you're buying coffee at a local café or shopping online internationally, the same unified balance powers all your card transactions.

Virtual Account Transfers: Wirex Pay can provision virtual bank accounts (SEPA for Europe, ACH for the US, Faster Payments for the UK) that are linked to your AA balance. When someone sends you a bank transfer to these account details, the funds automatically increase your on-chain balance. Similarly, you can send bank transfers that debit from your AA balance.

This unified approach means you don't need to manage separate balances for crypto transactions, card spending, and bank transfers - everything draws from and adds to the same pool of funds in your AA wallet.

Funding and Withdrawal Flows

Your AA balance can be funded and withdrawn through multiple channels, giving you maximum flexibility:

graph TB
    subgraph "Funding Your Balance"
        A[Crypto Deposit] -->|Direct blockchain transfer| AA[AA Wallet Balance]
        B[Bank Transfer] -->|SEPA/ACH/Faster Payments| OR[Virtual Account]
        OR -->|Convert fiat to crypto| AA
    end
    
    subgraph "Using Your Balance"
        AA -->|Instant debit| CP[Card Payments]
        AA -->|Bank  transfer| VA[Virtual Account] -->|Bank transfer| BW[Bank Withdrawal]
        AA -->|Direct blockchain transfer| CD[Crypto Withdrawal]

    end
    
    style AA fill:#4CAF50,stroke:#333,stroke-width:3px,color:#fff
    style CP fill:#2196F3,stroke:#333,stroke-width:2px,color:#fff
    style VA fill:#2196F3,stroke:#333,stroke-width:2px,color:#fff
    style OR fill:#2196F3,stroke:#333,stroke-width:2px,color:#fff
    style CD fill:#FF9800,stroke:#333,stroke-width:2px,color:#fff
    style BW fill:#FF9800,stroke:#333,stroke-width:2px,color:#fff

Funding Methods:

Crypto Deposits: You can fund your AA wallet by sending cryptocurrency directly from any external wallet or exchange. The blockchain transfer settles on-chain, and your balance is immediately available for spending through cards or virtual accounts.

Bank Transfers with On-Ramp: Wirex Pay provides virtual bank account details (SEPA, ACH, or Faster Payments depending on your region) that you can use to receive traditional bank transfers. When fiat currency arrives at these details, our integrated on-ramp service automatically converts it to cryptocurrency and credits your AA wallet balance. This enables you to fund your blockchain wallet using familiar banking methods.

Withdrawal Methods:

Card Transactions: Your Wirex Pay card enables instant spending at any merchant worldwide. When you make a purchase, funds are immediately debited from your AA balance and transferred to Wirex Pay's Master Account, which then settles with merchants through traditional card networks.

Crypto Withdrawals: You can transfer funds directly from your AA wallet to any external cryptocurrency wallet or exchange. After the Execution Delay Policy time-lock expires, your withdrawal completes on-chain.

Bank Withdrawals with Off-Ramp: When you need fiat currency in your traditional bank account, Wirex Pay's off-ramp service converts cryptocurrency from your AA balance to fiat and initiates a bank transfer to your nominated account. You receive funds via SEPA, ACH, or Faster Payments, depending on your region.

This multi-channel approach means your AA balance truly becomes a bridge between the blockchain and traditional financial systems, letting you move value seamlessly between both worlds while using a single balance for all your payment needs.

Card Transaction Flow

When you use your Wirex Pay card, a complex series of operations happens in milliseconds to securely authorize and complete your purchase:

sequenceDiagram
    autonumber
    participant CH as Cardholder
    participant MS as Merchant System
    participant CN as Card Network
    participant WP as Wirex Pay
    participant EU as On-chain user (AA)

    CH->>MS: Initiate Transaction Request
    MS->>CN: Send Transaction Request
    CN->>WP: Route Request (via BIN)
    WP->>WP: Verify Cardholder Details Perform Fraud & Risk Checks
    WP->>EU: Check AA Balance
    WP->>EU: Initiate charge to Master Account
    EU-->>WP: Transfer to Master Account
    WP->>CN: Send Final Authorization Response
    CN->>MS: Deliver Final Response
    MS->>CH: Notify Transaction Outcome

1. Transaction Initiation

You present your card at a merchant - whether tapping contactlessly at a point-of-sale terminal or entering your card details for an online purchase. The merchant's system captures your transaction details and initiates an authorization request.

2. Network Routing

The merchant's payment processor sends the authorization request to the card network (Visa, Mastercard, etc.). The card network identifies Wirex Pay as your card issuer by reading your card's Bank Identification Number (BIN) and routes the request to our platform for processing.

3. Verification and Risk Assessment

Wirex Pay receives the authorization request and immediately performs multiple layers of verification:

  • We validate your cardholder details and confirm your card is active and in good standing
  • Our fraud detection systems analyze the transaction for suspicious patterns or anomalies
  • Risk assessment algorithms evaluate the transaction against your spending history and profile
  • We query your on-chain AA wallet to verify you have sufficient funds available

This entire verification process happens in real-time, typically completing in under a second.

4. On-Chain Fund Securing

Once all verifications pass, Wirex Pay initiates a charge operation against your AA wallet. The Funds Management Executor module automatically executes an on-chain transaction that transfers the exact purchase amount from your wallet to Wirex Pay's Master Account. This immediate on-chain transfer is what secures the funds and guarantees payment to the merchant.

Because this happens through the executor module rather than requiring your manual approval, the transaction completes instantly while you're still at the checkout counter. Meanwhile, the Execution Delay Policy ensures that you cannot initiate conflicting transfers during this critical window.

5. Authorization Response

With the funds successfully secured on-chain, Wirex Pay generates a final authorization response and sends it back through the card network to the merchant. The merchant receives approval, and your transaction is complete. You receive your goods or services, and the merchant is guaranteed payment.

6. Settlement

Behind the scenes, the transaction enters the standard card network settlement process. During the next settlement cycle, funds flow from Wirex Pay's Master Account to the merchant's acquiring bank, completing the traditional payment infrastructure's requirements. From your perspective, the transaction is already complete - your on-chain balance updated instantly when you made the purchase.

Key Advantages

Instant Spending: Your digital assets become immediately spendable at millions of merchants worldwide, with no delays or manual approvals required for each transaction.

Self-Custody: You maintain full custody of your funds until the moment of purchase. There's no need to pre-load a custodial account or trust Wirex Pay with prolonged access to your assets.

Fraud Protection: The dual-module security architecture with execution delays and controlled executor access provides robust protection against various fraud vectors while maintaining transaction speed.

Universal Acceptance: Because Wirex Pay integrates with existing card networks, your blockchain assets become spendable anywhere cards are accepted - no merchant integration or cryptocurrency knowledge required.

Transparency: Every transaction is recorded on-chain, providing an immutable audit trail of your spending while the off-chain balance projection keeps you informed in real-time.

Getting Started

Integrating with Wirex Pay as a partner involves connecting to our comprehensive API infrastructure, which handles wallet deployment, balance management, card issuance, and transaction processing. Our partner portal provides detailed technical documentation, endpoint references, and integration guides to help you build on our platform and offer blockchain-powered payment solutions to your users.

Updated 6 days ago