NFT Cross-Chain Bridge Helper for Collection

WHAT IT DOES

NFT Cross-Chain Bridge Helper for Collection is a specialized browser extension that enables you to bridge entire NFT collections—or any subset of NFTs within a collection—from one EVM chain to another. When you view a collection page on a supported marketplace, the tool automatically detects the collection contract address and displays key metrics including floor price, total supply, holder count, and your personal wallet balance. It then presents a configuration panel where you select a bridge protocol (LayerZero, Axelar, or Chainlink CCIP), a destination chain (Ethereum, Polygon, Arbitrum, Optimism, or Base), and the number of NFTs to bridge. The tool calculates estimated bridge protocol fees and gas costs for both source and destination chains, then constructs a transaction sequence that: (1) approves the bridge contract to transfer your NFTs, (2) locks or burns the NFTs on the source chain, and (3) sends a cross-chain message to mint equivalent NFTs on the destination chain at your specified wallet address.

WHERE IT RUNS

This overlay operates on OpenSea collection pages, detecting the collection address from the URL and page DOM. It works in any browser that supports the BotGentz extension framework and has an EVM-compatible wallet extension installed. The panel automatically updates when you navigate between different collection pages, resetting its data and configuration for the new collection.

HOW TO USE

Install the extension and navigate to an NFT collection page on OpenSea. The panel will automatically detect the collection address and display collection metrics along with your wallet balance. Select your preferred bridge protocol from the dropdown menu, choose a destination chain, enter the number of NFTs you wish to bridge (up to your wallet balance), and optionally specify a different destination wallet address (defaults to your current wallet). Configure advanced settings including gas price multiplier and auto-approve toggle. Click "Estimate Gas" to check current network conditions, then click "Bridge NFTs" to initiate the process. Your wallet will prompt you to confirm the approval transaction, then the bridge transaction. The panel will display real-time status updates throughout the process, including confirmation of approvals, lock/burn execution, and cross-chain message initiation.

MECHANISM: MULTI-PROTOCOL BRIDGE ROUTER WITH DYNAMIC FEE ORACLE

Unlike single-protocol bridge tools that lock you into one infrastructure provider, this extension implements a protocol-agnostic bridge router that dynamically selects the optimal bridge based on user preference, destination chain, and current network conditions. It constructs protocol-specific transaction calldata by loading minimal ABIs for each supported bridge at runtime, including the LayerZero endpoint, Axelar gateway, and Chainlink CCIP router interfaces. The tool queries each protocol's fee oracle contract using eth_call to retrieve the current bridge fee in the source chain's native token, then adds the estimated gas costs for both chains (using current gas price multiplied by estimated gas limits). The approval step uses the ERC-721 setApprovalForAll() function to grant the bridge contract permission to transfer NFTs, which is required for both lock-and-mint and burn-and-mint bridge patterns. The bridge initiation call varies by protocol: LayerZero uses the send() function with adapter parameters, Axelar uses callContract(), and CCIP uses sendMessage() with the EVM2EVMMessage structure. The tool automatically detects the appropriate function signature and encodes the destination chain identifier, recipient address, and NFT IDs. After the transaction is mined, the tool logs the transaction hash and provides a link to the block explorer for tracking the cross-chain message status.

THE PANEL

The overlay panel is fully draggable via its title bar and remembers its position per-site using GM_setValue. It snaps to the nearest edge when dragged within 40px of any screen boundary. The panel includes clear sections for collection details (name, address, floor price, supply, holders, your balance), bridge configuration (protocol selection, destination chain, count input, destination wallet), fee estimation, and action buttons. The status area provides real-time feedback on wallet connection, collection data loading, approval progress, and transaction status. Pressing Escape temporarily dismisses the panel until you navigate to a new collection page or manually reactivate via the extension toolbar button. The panel automatically refreshes its data when you navigate to a new collection, re-checking balance and collection metrics.

PLEASE NOTE

This extension requires the free BotGentz framework extension to be installed and active. You must also have a real EVM-compatible wallet extension (such as MetaMask, WalletConnect, Coinbase Wallet, or Rabby) already installed in your browser—the overlay uses your wallet's RPC provider to make eth_call requests and to sign transactions. This tool works exclusively with Ethereum Virtual Machine chains including Ethereum mainnet, Polygon, Arbitrum, Optimism, and Base. The bridge protocols supported are LayerZero, Axelar, and Chainlink CCIP; each has varying support for different destination chains and may require specific contract addresses that are chain-dependent. Because bridge protocols, NFT marketplace interfaces, and cross-chain relayer networks frequently update, the tool's transaction-building and fee estimation scripts may require periodic updates. We commit to releasing compatibility updates within 48 hours of any reported major bridge protocol or marketplace change. No private keys, wallet balances, browsing history, or NFT ownership data are ever collected, transmitted, or stored—all blockchain reads and writes are performed directly from your local wallet RPC provider to public blockchain nodes. The tool cannot verify that the destination chain contract actually mints the exact same NFT attributes or metadata as the source chain; cannot detect if the bridge protocol's relayer is currently operational or if the cross-chain message will be delivered within a predictable time; cannot guarantee that the destination chain's NFT contract supports the bridge protocol's minting interface; does not support bridges that require off-chain relayers with manual confirmation steps beyond the initial transaction; and cannot verify the authenticity of the collection on the destination chain or protect against destination chain contract impersonation.