Qube Bridge Frontend | for QubeSwap Dex

A Frontend Bridge for EVM Blockchains (Ethereum, BSC, Qubetics, Avalanche etc...)

This is a Next.js project bootstrapped with create-next-app.

Getting Started

First, run the development server:

nvv use 20

npm install
npm run dev
# or
yarn install
yarn dev

Open http://localhost:3000 with your browser to see the result.

Notice:

If you are looking to add your token as an Original Chain
token and Destination token to QubeBridge, make sure it is Mintable/Burnable
first and has the "supportsInterface" function if it doesnt, you can copy the
function code below and add it to your token contract src code.

In Case: If your token on the Origin Chain is not a Mintable/Burnable token,
you will have to deploy a custom token contract on the Destination chain with
the Mintable/Burnable functions along with the "supportsInterface" function.

import "https://github.com/mabbleio/contract-deps/blob/main/interfaces/IMintableERC20.sol";

Step 3: Ensure Mintable Tokens Implement ERC165

All tokens marked as mintable must now implement:

function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
    return
        interfaceId == type(IERC165).interfaceId ||
		interfaceId == type(IMintableERC20).interfaceId ||
        super.supportsInterface(interfaceId);
}

QubeBridge: Production Readiness Checklist

Secure Cross-Chain Bridge for QubeSwap

This document outlines the final production readiness checklist for QubeBridge, ensuring security, efficiency, and reliability before deployment.

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📋 Production Checklist Overview

Security & Correctness

Category	Status	Implementation Details	Verification
Overflow Protection	✅ Fixed	Uses OpenZeppelin's Math.mulDiv for all fee calculations to prevent arithmetic overflows	Test Cases
Reentrancy	✅ Fixed	Implements Checks-Effects-Interactions pattern with ReentrancyGuard on all state-changing functions	Audit Report
Access Control	✅ Good	Strict role separation with: - controller (daily operations) - multisig (emergency actions) - processor (validation)	AccessControl.sol
Input Validation	✅ Improved	Comprehensive validation for: - Supported tokens/chains - Minimum amounts - Destination chain IDs - Deadline bounds	InputValidationTest.t.sol

Performance Optimizations

Category	Status	Implementation Details	Gas Savings
Gas Optimizations	✅ Applied	- Cached array lengths in loops - unchecked blocks for counter increments - Minimized storage reads	~15-20% reduction
Redundant Storage	✅ Fixed	Removed supportedChainIds[] array (redundant with mapping-based checks)	5,000 gas/slot

Oracle & External Systems

Category	Status	Implementation Details	Config
Oracle Timeouts	✅ Fixed	Increased from 45 minutes to 1 hour for better Chainlink Automation reliability	oracleTimeout = 3600
Chainlink Support	✅ Good	- Configurable per-chain support - Graceful fallback to manual validation	ChainlinkConfig.sol

Monitoring & Transparency

Category	Status	Implementation Details	Example Events
Events	✅ Good	Emits comprehensive events for: - Bridge initiations - Validations - Completions - Cancellations - Emergency actions	BridgeInitiated BridgeCompleted TransactionCancelled

Attack Mitigations

Category	Status	Implementation Details	Protection Level
Front-Running	✅ Mitigated	- 48-hour delay for controller cancellations - Timelocks on critical operations - Two-step ownership transfer	High
Replay Attacks	✅ Fixed	Nonce system per (user, srcChain, destChain) combination	Complete
Unauthorized Access	✅ Fixed	All privileged functions use onlyRole modifiers	Complete

---

QubeBridge FAQ

🌉 General Questions

1. What is QubeBridge?

QubeBridge is a private, secure cross-chain bridge operated exclusively by Mabble Protocol for QubeSwap DEX users. It enables:

• Seamless asset transfers between supported blockchains
• Off-chain validation via a backend processor
• Multisig-controlled admin operations for security
• Chainlink Automation support for supported chains

2. Who can use QubeBridge?

• QubeSwap users: To bridge assets between supported chains
• Admins:
  • Controller: Manages daily operations (adding tokens/chains, fees)
  • Processor: Validates transactions
  • Multisig: Handles emergency operations

3. What chains/networks are supported?

• The bridge is deployed on a source chain (srcChainId)
• Additional chains can be added by the controller
• Check supported chains with:

  function getSupportedChainIds() external view returns (uint256[] memory)

4. What tokens are supported?

• Native ETH (use address(0))

• ERC20 tokens (up to 100 by default)
  

  • Mintable tokens (burn/mint instead of transferring)
    Check support with:
    

function isSupportedToken(address token) public

5. What are the fees?

• Default fee: 2% (configurable up to 5%)

• Example: Bridging 100 USDC → 2 USDC fee (sent to feeRecipient)

• Minimum amount: Enforced per token (e.g., minAmount[token])

6. What's the difference between mintable and non-mintable tokens?

Type                    Mechanism                                                Liquidity Needed?
Mintable              Burn on source, mint on destination           ❌ No
Non-mintable      Lock in bridge, transfer from pool              ✅ Yes

7. What's the liquidity pool for?

Bridge:

• Holds non-mintable tokens (e.g., USDC, DAI) for bridging

Management:

• Deposit: depositLiquidity(token, amount) (controller/multisig)
• Withdraw: withdrawLiquidity(token, amount) (emergency only)

© 2025 Mabble Protocol. All rights reserved.
QubeBridge is a private bridge operated by Mabble Protocol exclusively for QubeSwap Dex.