Cross-Chain Fee Payment Abstraction Tool

WHAT IT DOES

This tool evaluates cross-chain fee payment abstraction readiness, helping users determine if they can pay transaction fees across multiple EVM chains using an abstraction layer. Given a fee abstraction contract address, a list of chain configurations (chain ID, RPC URL, native token symbol, and estimated fee), an optional fee token address, and an optional user address, it reads the user's native coin balance from each chain via RPC, the contract fee balance, whether the estimated fee can be paid, and the user's fee token balance and allowance if a token address is provided. The tool then displays a clear status for each chain—Ready, Insufficient, or Pending—and provides a summary of chains where fee payment is possible. All data is pulled directly from the blockchain and RPC endpoints in real time, providing a transparent, comprehensive view of cross-chain fee payment abstraction readiness.

HOW TO USE

Connect your wallet using the Connect button in the header, or enter a user address manually. Select the target network from the dropdown—Ethereum Mainnet, Polygon, Optimism, Arbitrum One, Base, or Sepolia testnet. Enter the fee abstraction contract address. Enter each chain configuration on a separate line in the format: chainId,rpcUrl,nativeSymbol,estimatedFee (e.g., "1,https://eth.llamarpc.com,ETH,0.001" for a 0.001 ETH estimated fee). Optionally, provide a fee token address to check token balance and allowance, and a user address (defaults to connected wallet). Click "Check fee payment." The tool will fetch the live native balance from each chain's RPC, the contract fee balance, canPayFee status, and token balance and allowance if provided. Results appear in the card below with a prominent fee status badge (X chain(s) ready for fee payment, Insufficient balance for fee payment, or No fee payment available), a detailed list of each chain showing its native balance, estimated fee, contract balance, and canPayFee status, and a summary of chains and fee payment readiness. Use this information to identify which chains support fee payment abstraction.

CROSS-CHAIN FEE PAYMENT ABSTRACTION VERIFICATION WITH BALANCE AND ESTIMATED FEE ANALYSIS

The tool provides comprehensive cross-chain fee payment abstraction verification through multiple on-chain reads and RPC queries. First, it calls getFeeBalances() on the fee abstraction contract with the user address and an array of chain IDs to retrieve all contract-stored fee balances in a single batch call. It then queries each chain's RPC endpoint using getBalance() to get the live native coin balance. The canPayFee() function verifies all conditions—sufficient native balance, contract fee balance, and any contract-specific requirements. The getEstimatedFee() function returns the estimated fee for each chain, which is compared against the user's balance. If a fee token address is provided, the tool reads the user's token balance using balanceOf() and allowance using allowance() for the fee contract. The overall fee payment status is determined by checking canPayFee for each chain—Ready if true, Insufficient if balance is insufficient, Pending if no balance. All factors are combined to provide a clear, actionable view of cross-chain fee payment abstraction readiness with detailed per-chain analysis.

WHAT IT CANNOT SEE

This tool cannot guarantee fee payment execution—on-chain conditions may change between the check and the payment transaction. It cannot predict gas price movements or ensure that the estimated fee will be sufficient. It cannot verify off-chain fee conditions or ensure that the fee abstraction contract is correctly configured. It cannot ensure bridge solvency or detect changes in bridge state that could affect fee payments. It cannot detect fee manipulation risks or ensure that fees are accurately calculated. It cannot assure that the fee abstraction contract is free from vulnerabilities, bugs, or malicious code. It cannot verify that the fee contract address or chain configurations are correct. It cannot detect front-running or other execution risks. It cannot provide financial or legal advice or guarantee that paying fees is safe. All data is provided as-is for informational purposes only; any reliance on the tool's output for fee payment decisions is the sole responsibility of the user.

PLEASE NOTE

This tool supports EVM-compatible chains only: Ethereum Mainnet (1), Polygon (137), Optimism (10), Arbitrum One (42161), Base (8453), and Sepolia testnet (11155111). Solana, Tron, Starknet, SUI, TON, Aptos, Bitcoin, Cosmos, and XRP are not supported. The tool requires a Web3 provider (MetaMask or WalletConnect) and access to RPC endpoints for the configured chains. It does not store any wallet data, chain configurations, or fee records. All queries are performed directly against the blockchain and RPC endpoints in real time. The tool only provides read-only information and does not execute any transactions. Estimated fees, balances, and canPayFee statuses are contract-defined and RPC-derived values and do not guarantee payment success. Always verify critical data independently through block explorers and consult with financial advisors before making any fee payment decisions.