🛠️ Backend / Indexer Role

The backend acts as a bridge coordinator — it verifies Ethereum transactions and triggers minting on Avalanche.

• Receives a call from the frontend after ETH is locked
• Scans Ethereum logs from currentBlock - 1 to currentBlock + 1
• Finds and verifies the event emitted by the ETH contract
• Generates a unique lockId from the transaction
• Calls Avalanche contract's backend_confirmation() function
• Avalanche contract checks the mapping:

  mapping(bytes32 => mapping(address => mapping(uint256 => uint8)))

• If valid, it increases confirmation count
• Once confirmations reach 2, Avalanche contract calls mint() to mint wrapped ETH

🔐 Why It’s Important

• Verifies on-chain logs to prevent fraud or spoofing
• Triggers cross-chain mint securely only when ETH is truly received
• Ensures confirmations are tracked before minting

This backend flow makes the bridge secure, verifiable, and ensures the wrapped tokens are minted only after a valid ETH deposit.