Vault Token

Overview

The Vault Token is designed to wrap multiple variants of the same underlying asset (e.g., USDC from different chains) into a single, unified token.

Core Features

1. Multi-Asset Support

   • Supports multiple underlying tokens

   • Configurable deposit limits per token

   • Decimal normalization for different token standards

   • Fee mechanisms for deposits and withdrawals

2. Rate Limiting

   • Built-in rate limiting for all transfers

   • Consults rate limiter for mints, burns, and transfers

   • Ensures controlled token movement

Token Configuration

Token Info Structure

struct TokenInfo {
    uint8 decimals;      // Decimals of the underlying token
    uint256 depositFee;  // Fee in basis points (e.g., 50 = 0.5%)
    uint256 withdrawalFee; // Fee in basis points
    uint256 maxDeposit;  // Maximum allowable deposit
    bool isSupported;    // Whether the token is supported
}

Core Operations

1. Deposits

function deposit(address token, uint256 amount) external {
    // 1. Verify token is supported
    // 2. Check deposit limits
    // 3. Transfer underlying token to vault
    // 4. Apply deposit fee if configured
    // 5. Mint vault tokens to user
}

1. Withdrawals

function withdraw(address token, uint256 amount) external {
    // 1. Burn vault tokens from user
    // 2. Apply withdrawal fee if configured
    // 3. Transfer underlying token to user
}

1. Rate-Limited Transfers

function _update(address from, address to, uint256 value) internal override {
    // Consult rate limiter before any transfer
    rateLimits.update(from, to, value, totalSupply());
    super._update(from, to, value);
}

Security Features

1. Deposit Controls

   • Maximum deposit limits per token

   • Rate limiting on all transfers

   • Decimal normalization for safety

2. Access Control

   • Owner-controlled token configuration

   • Protected fee recipient updates

   • Restricted token support management

3. Fee Management

   • Configurable deposit/withdrawal fees

   • Protected fee collection mechanism

   • Fee recipient management

Use Cases

1. Asset Unification

   • Wrap USDC from multiple chains into a single vault token

   • Simplify cross-chain asset management

   • Enable unified liquidity pools

2. Fee Generation

   • Collect fees on deposits/withdrawals

   • Generate revenue from cross-chain movements

   • Incentivize liquidity provision

3. Rate-Limited Transfers

   • Control token velocity

   • Prevent large sudden movements

   • Enhance security through movement restrictions

4. Cross chain token managment

   • Controls movement and accounting for tokens deployed across multiple chains

Configuration Methods

// Add support for a new underlying token
function addSupportedToken(
    address token,
    uint8 decimals,
    uint256 depositFee,
    uint256 withdrawalFee,
    uint256 maxDeposit
) external onlyOwner;

// Add liqudity for a new crosschain token
function depositAndBurn(address token, uint256 amount) external;

// Update existing token configuration function updateToken( address token, uint256 depositFee, uint256 withdrawalFee, uint256 maxDeposit ) external onlyOwner;

## Query Methods

```solidity
// Get vault reserves for all supported tokens
function getVaultReserves() external view returns (
    address[] memory tokens,
    uint256[] memory balances
);

// Get complete token configuration and balances
function getAllTokenInfo() external view returns (
    address[] memory tokens,
    TokenInfo[] memory infos,
    uint256[] memory reserves
);