Meta-Transaction Signature Relay Tool

WHAT IT DOES

Meta-Transaction Signature Relay Tool is a developer-focused tool that enables users to sign and relay meta-transactions—transactions signed off-chain and submitted by a relayer who pays the gas. Unlike standard transaction submission where the signer pays gas, this tool allows users to sign transactions that are then forwarded to a relayer contract, which validates the signature and executes the transaction on behalf of the user. It reads meta-transaction request parameters, validates signature validity, checks relayer contract state, manages nonce status, tracks user's pending meta-transactions, and estimates gas for meta-transactions. The tool supports Ethereum, Polygon, Arbitrum, Optimism, Avalanche, BNB Chain, and Base, providing a unified interface to prepare, sign, and relay meta-transactions across multiple networks. This is essential for dApps implementing gasless transactions, user onboarding, and applications that want to cover gas costs for their users.

HOW TO USE

Connect your wallet using WalletConnect or a compatible browser extension. Ensure your wallet is on the network where the relayer contract is deployed. Enter the relayer contract address, target contract address, call data in hex format, and the value to send. Optionally specify a nonce; if left blank, the tool will attempt to read it from the relayer contract. Click "Prepare meta-transaction" to validate the parameters and build the EIP-712 typed data structure. The tool displays the transaction details and prepares the domain separator. Click "Sign & relay" to sign the meta-transaction using EIP-712 typed data signing, then submit the signed payload to the relayer contract. The relayer contract validates the signature and executes the transaction. The tool displays the relay transaction hash and the final gas cost.

ADAPTIVE EIP-712 SIGNATURE GENERATION AND RELAY ENGINE

The core technical mechanism that distinguishes this tool is its adaptive EIP-712 signature generation and relay engine. Unlike simple transaction signing that only produces raw signatures, this tool implements the full EIP-712 typed data signing standard, which provides structured, human-readable data that wallets can display to users. The engine first constructs the EIP-712 domain separator using the relayer contract address and chain ID, ensuring signatures are bound to the specific contract and network. It then builds the typed data message containing the from address, to address, value, data, and nonce—all typed and encoded according to the EIP-712 specification. The engine reads the user's current nonce from the relayer contract to prevent replay attacks, and validates that the target contract and call data are properly formatted. Once the user signs, the engine constructs the relay transaction call to the relayer contract's relay() function, passing the from, to, value, data, nonce, and signature. The engine estimates gas for the relay call and submits the transaction. All RPC calls are wrapped with timeout and retry logic, and the tool automatically falls back to a secondary provider if the primary endpoint fails or rate-limits, ensuring nonce reads and relay submissions complete even during network congestion.

WHAT IT CANNOT SEE

The tool cannot guarantee that meta-transactions will be relayed successfully if the relayer contract's nonce is out of sync, the user's signature is invalid or expired, the relayer network is congested, or the meta-transaction parameters exceed the relayer contract's limits. It has no visibility into the relayer's internal state beyond what the contract exposes, nor can it predict if the relayer will choose to relay the transaction. The tool cannot detect if the relayer contract's nonce is incremented by another pending transaction. It does not monitor meta-transactions after relay—it is a relay tool, not a tracking service. The tool cannot interact with non-EVM chains, private networks, or relayer contracts that do not implement the standard EIP-712 interface it expects.

PLEASE NOTE

This tool is designed exclusively for EVM-compatible blockchain networks. It supports Ethereum, Polygon, Arbitrum, Optimism, Avalanche, BNB Chain, Base, and similar chains. Non-EVM networks such as Solana, Cosmos, or Bitcoin are not supported. Always verify the relayer contract address and parameters before signing—the tool does not validate contract safety or relay terms beyond basic verification. The tool provides estimates only—actual gas costs are determined at the time of transaction execution. Users are responsible for understanding meta-transaction risks, including the possibility that the relayer may fail to forward the transaction.