Mantle Bridge Helper

WHAT IT DOES

Mantle Bridge Helper is your comprehensive bridge assistant for the Mantle network. It automatically detects deposit and withdrawal interfaces on Mantle bridge pages, reading bridge amounts, token types, destination addresses, and direction directly from the page. The tool then fetches real-time gas prices from both Ethereum mainnet (L1) and Mantle (L2), calculates the total cost including L1 gas, L2 gas, and bridging fees, and displays everything in a clear summary panel. With one click, you can execute your bridge transaction, with the script handling transaction submission, confirmation monitoring across both layers, and status tracking from initiation to final settlement. The tool supports both ETH and MNT token bridging, as well as popular ERC-20 tokens.

WHERE IT RUNS

This script runs on all official Mantle interfaces, including mantle.xyz, bridge.mantle.xyz, and mantle.io domains. It works on bridge deposit and withdrawal pages, token transfer interfaces, and any transaction submission form that bridges assets between Ethereum mainnet and Mantle L2. The tool automatically detects the bridge interface regardless of how it's structured and adapts its cost calculations to the specific contract interactions present on the page.

HOW TO USE

Install the script through the BotGentz userscript manager. Navigate to any Mantle bridge page. Click "Connect Wallet" to link your EVM wallet extension—the tool supports MetaMask, Coinbase Wallet, and any Web3-compatible wallet. The panel will automatically detect the bridge interface and display all relevant information: bridge amount, token type, direction (deposit or withdraw), destination address, L1 gas price, estimated L2 gas cost, bridge fee percentage, and total cost in ETH or MNT. Adjust your bridge amount on the page, and the panel updates in real-time. Use the "Execute Deposit" or "Execute Withdraw" buttons to initiate your transaction. The script handles transaction signing, submission, and confirmation monitoring, alerting you when the bridge completes on both chains.

DUAL-LAYER GAS AGGREGATION WITH MANTLE'S DATA AVAILABILITY LAYER

Unlike simple bridge calculators that only estimate L1 gas, this tool performs live RPC queries through window.ethereum to fetch current gas prices on Ethereum mainnet, then applies a sophisticated cost model that accounts for Mantle's unique fee structure. The engine uses separate gas estimates for L1 (190,000 gas for deposit/withdraw contract interactions) and L2 (580,000 gas for settlement and finalization), then applies the current L1 gas price to both. It factors in the bridge fee (typically 0.1-0.3% of bridge amount) and uses the actual current gas price rather than static estimates. When ethers.js is available, the engine further refines estimates using contract ABI inspection and on-chain fee data, providing the most accurate bridge cost picture available for Mantle bridging. The tool also accounts for Mantle's data availability layer costs, which add unique variables to the total cost calculation.

THE PANEL

The floating panel is fully draggable and snap-to-edge enabled. You can collapse it to a compact bubble when not in use, resize it to your preferred dimensions, and it remembers its position across page loads using persistent storage. Press Escape to quickly dismiss the panel. The panel automatically updates every 30 seconds with fresh gas data and bridge status, ensuring you always have current information before committing to a transaction.

PLEASE NOTE

This script requires the free BotGentz extension to be installed in your browser—it does not run as a standalone extension. You also need a real EVM wallet extension already installed and configured. The tool works exclusively with Mantle bridge interfaces and compatible bridge pages. Bridge interfaces may change over time, which could temporarily break detection; the script will notify you if it cannot find the bridge components. Token approval transactions for ERC-20 bridging add additional cost and complexity. No user data is collected, stored, or transmitted—all wallet interactions stay local in your browser. Bridge success depends on network conditions, gas availability, and bridge contract state; the tool provides cost estimates and execution assistance but cannot guarantee bridge completion if network congestion or contract issues occur.