Wirex Baas Crypto

Wirex BaaS Crypto Asset Management

This skill covers crypto asset management within the Wirex Banking-as-a-Service platform: the unified balance model, wallet queries, multi-chain deposit addresses, ERC20 withdrawals, token addresses, and smart contract ABIs.

Unified Balance Model

Wirex BaaS uses a unified balance model where all user funds are represented as wrapped stablecoins on the Base chain:

All balances across the platform (card spending, bank transfers, crypto deposits) are unified into these two tokens. There is no need to manage multiple token balances or perform manual conversions.

Token Wrapping

• Deposits: When a user deposits USDC, USDT, or EURC, the tokens are bridged to Base and wrapped into WUSD or WEUR at a 1:1 ratio. The wrapping process mints the corresponding W-token.
• Withdrawals: When a user withdraws, WUSD unwraps to USDC on Base, and WEUR unwraps to EURC on Base. The process incorporates delay verification before execution to enhance security.

Direct Credit Minting

WUSD/WEUR can also be minted directly (without a deposit) in the following scenarios:

• Card refunds: Merchant refunds credit WUSD/WEUR back to the wallet.
• Bank transfers: Incoming SEPA or ACH transfers mint WUSD/WEUR.
• Peer-to-peer (P2P): Internal transfers between Wirex users.
• Rewards: Cashback, referral bonuses, and promotional credits.

Wallet Queries

GET /api/v1/wallet

Retrieve the current wallet balances for an account.

Headers:

Response:

{
  "balances": [
    {
      "token_symbol": "WUSD",
      "token_address": "0xb4bB2032A73A53C0Aa7Dc9ee2d9658a978fA7bC2",
      "balance": "1000000000000000000",
      "reference_balance": "1.00",
      "reference_currency": "USD"
    },
    {
      "token_symbol": "WEUR",
      "token_address": "0x379e120C1921bFD8f5E0A1a3C699e7e800b66606",
      "balance": "500000000000000000",
      "reference_balance": "0.50",
      "reference_currency": "EUR"
    }
  ]
}

• balance is the raw on-chain value with 18 decimals.
• reference_balance is the human-readable amount.
• reference_currency indicates the fiat equivalent.

Global Deposit Addresses (Multi-Chain via Rhino.fi)

Wirex uses the Rhino.fi SDK to generate deposit addresses across 9 supported chains. A single "global address" set allows users to receive funds on any of these networks, which are then bridged to Base and wrapped into WUSD/WEUR.

Supported Chains

All EVM chains share a single global deposit address. TRON and Solana get separate addresses due to architectural differences. Addresses are reusable across multiple deposits.

Supported Deposit Tokens

Minimum deposit: 1 USD/EUR equivalent.

Linking Global Addresses

After generating deposit addresses via the Rhino.fi SDK, link them to the Wirex account:

POST /api/v1/wallets/global

{
  "wallet_address": "0x1234...abcd"
}

Retrieving Wallets

GET /api/v1/wallets

Filter by wallet_type=Global to retrieve only global deposit addresses.

See references/REFERENCE.md for the full Rhino.fi SDK configuration example, TRON/Solana address creation, and detailed request/response formats.

ERC20 Withdrawals

ERC20 withdrawals use a two-phase delay pattern to enhance security. The flow is:

1. Request phase: The user initiates a withdrawal request. The smart contract records the request with a valid_after timestamp determined by the ExecutionDelayPolicy.
2. Wait phase: The request remains pending until the valid_after time is reached.
3. Execute phase: After the delay expires, the withdrawal can be finalized.

Delay Values

Wirex SDK Methods

The Wirex SDK (@wirexapp/wirexpay-sdk) provides two approaches. Methods are namespaced under sdk.crypto.transfer:

Single-call (full transfer)

await sdk.crypto.transfer.makeFullErc20Transfer({
  tokenAddress: "0x...",
  toAddress: "0x...",
  amount: "1000000000000000000"
});

This method handles both phases internally, waiting for the delay to pass before executing.

Two-step (manual control)

// Step 1: Initiate the request
const request = await sdk.crypto.transfer.makeErc20TransferFirstPart({
  tokenAddress: "0x...",
  toAddress: "0x...",
  amount: "1000000000000000000"
});

// Step 2: After valid_after time has passed
await sdk.crypto.transfer.makeErc20TransferFinal(request);

This approach gives the integrator control over the waiting period and allows for UI updates or user confirmations between steps.

Pending Withdrawal Requests

GET /api/v1/withdrawal/requests (or via sdk.api.withdrawal.getWithdrawalRequests())

Returns all pending withdrawal requests for the account, including:

Webhooks

Wirex BaaS emits webhooks for crypto-related events:

See references/REFERENCE.md for full webhook payload examples.

Token Addresses

See overview ENVIRONMENTS.md for complete token address tables (sandbox and production, Base and Stellar). Sandbox token addresses are also in the sandbox skill.

ABI Reference

Smart contract ABIs for ContractRegistry, Accounts, TokensRegistry, Kernel, and ERC20 are documented in references/ABI-REFERENCE.md.