Unified Balance

Before You Start

Read the following guides before proceeding:

Overview

The Unified Balance represents a user's stable value across all operations in Wirex BaaS. Instead of holding multiple versions of USDT, USDC, or EURC across different blockchains, Wirex normalizes all stable value into:

• WUSD — Unified USD, for USD-equivalent value
• WEUR — Unified EUR, for EUR-equivalent value

These unified tokens exist on Base chain and provide a chain-agnostic, asset-agnostic model for all internal balances, transfers, and settlements.

Note: Cross-chain deposits via Smart Deposit Addresses are covered in Global Addresses. This document focuses on unified stablecoin mechanics.

Why WUSD and WEUR Exist

External stablecoins vary widely:

• Different token standards (ERC-20, TRC-20, SPL, KIP)
• Different decimal precision
• Chain-specific semantics and gas rules
• Inconsistent liquidity conditions
• Various settlement and finality models

This fragmentation makes unified accounting complex. WUSD and WEUR solve these issues by acting as canonical internal stablecoins for all accounting, settlement, and value transfers.

How Unified Tokens Are Created

Deposit Minting (Wrap)

When users deposit external stablecoins (USDC, USDT, EURC) to their Smart Wallet:

1. Deposit received on source blockchain
2. Transaction verified
3. Equivalent WUSD or WEUR minted at 1:1 ratio
4. User's Unified Balance credited

Original tokens are held in reserve while unified tokens represent the internal value.

Direct Credit Minting

Certain operations create WUSD/WEUR directly:

• Card refunds — Merchant refund credits
• Bank transfers — Incoming fiat via SEPA/ACH
• Internal transfers — Peer-to-peer within Wirex
• Rewards — Cashback and promotional credits

These mint unified tokens directly, maintaining 1:1 backing through Wirex reserve management.

Minting Flow

On-Chain Deposits              Off-Chain Credits
 USDC, USDT, EURC               Card Refund, Bank Transfer
        ↓                               ↓
   Wrap (1:1)                    Direct Mint (Fiat-backed)
        ↓                               ↓
        └───────────────────────────────┘
                        ↓
              Smart Wallet (WUSD / WEUR)
                  Unified Balance

Minting Properties

Unwrap Mechanics (Withdrawals)

When sending value to an external blockchain address, unified assets are unwrapped into external stablecoins.

Unwrap Flow

sequenceDiagram
    participant User
    participant App
    participant Wallet as Smart Wallet
    participant Policy as Delay Policy
    participant Tokens

    Note over User,Tokens: Phase 1: Request
    User->>App: Initiate transfer
    App->>Wallet: Encode unwrap + transfer calls
    Wallet->>Policy: Create request()
    Policy-->>Wallet: Store with delay
    App-->>User: Request initiated

    Note over User,Tokens: DELAY PERIOD

    Note over User,Tokens: Phase 2: Execute
    User->>App: Execute transfer
    App->>Wallet: Send with nonce
    Wallet->>Policy: Verify delay passed
    Policy-->>Wallet: Approved
    Wallet->>Tokens: Burn WUSD, release USDC
    Wallet->>Tokens: Transfer to recipient
    App-->>User: Transfer completed

Supported Unwrap Paths

Token Addresses

Production (Base Mainnet - Chain ID 8453)

Sandbox (Base Sepolia - Chain ID 84532)

Retrieving Unified Balance

GET /api/v1/wallet

Response (balances excerpt):

{
  "balances": [
    {
      "token_symbol": "WEUR",
      "token_address": "0x5f0818Cfc6554aC3d018aeF81D310ABC1dcCcCD7",
      "balance": 7.27,
      "reference_balance": 8.40,
      "reference_currency": "USD"
    },
    {
      "token_symbol": "WUSD",
      "token_address": "0xD08C1401dd0E8aA012D9C7b4471d45FdC8f1C97E",
      "balance": 1581.07,
      "reference_balance": 1581.07,
      "reference_currency": "USD"
    }
  ]
}

Summary

WUSD and WEUR are the foundational unified stablecoins powering all Unified Balance mechanics in Wirex BaaS:

• Single canonical asset per currency
• Deterministic internal accounting
• Unified global liquidity
• Chain-agnostic operations
• Seamless unwrap → blockchain send workflows
• No developer management of token formats or bridging

By integrating with Unified Balance, developers gain a simple, reliable way to handle stablecoin value across any chain.