EIP-7702: How Transaction Fee Sponsorship Improves Web3 Wallet User Experience

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Ethereum Improvement Proposals (EIPs) continuously evolve the Ethereum ecosystem, addressing critical challenges and introducing innovative functionalities. Among these, EIP-7702 stands out as a pivotal upgrade focused on enhancing user experience (UX) within Web3 wallets. This proposal introduces a novel transaction type that enables externally owned accounts (EOAs) to temporarily operate like smart contracts, unlocking powerful new capabilities.

A central feature enabled by EIP-7702 is transaction fee sponsorship. This mechanism allows a third party, known as a sponsor, to pay the transaction (gas) fees on behalf of another user. This eliminates a significant barrier to entry: the need for users to always hold the blockchain's native cryptocurrency (ETH on Ethereum) simply to pay for transaction costs. This is particularly transformative for users who primarily interact with stablecoins, security tokens, or NFTs and wish to avoid holding volatile assets.

Implemented in May 2025 as part of the Pectra upgrade, EIP-7702 marks a crucial step toward full Account Abstraction, a long-discussed concept for making Ethereum accounts more flexible and user-friendly.

Core Benefits of EIP-7702

EIP-7702's new transaction type empowers EOAs by allowing them to load smart contract code temporarily. This foundational shift enables three major improvements for Web3 wallets and dApps:

This flexibility is a cornerstone for improving the overall usability and security of Web3 applications.

Implementing Transaction Fee Sponsorship with EIP-7702

This practical demonstration shows how to leverage EIP-7702 to sponsor gas fees for an ERC-20 token transfer on the Ethereum Sepolia testnet.

Scenario Setup

The test involves three key parties:

The goal is for the Sender to successfully transfer tokens without ever needing to own ETH, while the Sponsor covers the gas cost.

Technical Architecture: The Delegation Contract

Fee sponsorship is achieved through a delegation mechanism. The Sponsor sends a special EIP-7702 transaction. This transaction instructs the Sender's EOA to temporarily load and execute a smart contract called a Delegation Contract. This loaded contract then performs the desired action—in this case, calling the transfer function on the USDC ERC-20 contract to move funds from the Sender to the Receiver.

The entire process is governed by a critical new data field in the EIP-7702 transaction: the authorization_list. This list specifies which EOA (the Sender) is authorized to load which smart contract (the Delegation Contract) for this specific transaction.

A simple, example Delegation Contract was deployed for this test (0xebe707c39CFdA896376D618369bd80973318Fe8b). Its primary function is to execute a call to any specified contract with any given data.

Disclaimer: This contract is for demonstration and testing purposes only. It has not been audited for security and should not be used in a production environment.

pragma solidity ^0.8.0;
contract EIP7702Delegation {
    struct Call {
        address to;
        uint256 value;
        bytes data;
    }
    event CallExecuted(
        address indexed sender,
        address indexed to,
        uint256 value,
        bytes data
    );
    event Executed(address value);

    function execute(Call calldata call) external payable {
        (bool success, ) = call.to.call{value: call.value}(call.data);
        require(success, "reverted");
        emit Executed(address(this));
        emit CallExecuted(msg.sender, call.to, call.value, call.data);
    }
}

Building the EIP-7702 Transaction

The transaction is constructed using TypeScript and the ethers.js library (v6.13.7). The process involves several key steps:

  1. Creating the Authorization List: The core of the delegation. The Sender must sign a message authorizing their EOA to load the specific Delegation Contract for this transaction on the current chain. This signed authorization is included in the authorization_list field.
  2. Encoding the ERC-20 Transfer: The calldata for the USDC transfer function call is encoded. This defines what action the Delegation Contract will ultimately perform.
  3. Encoding the Delegation Contract Call: The previously encoded transfer calldata is packaged into a call to the Delegation Contract's execute function.
  4. Assembling and Signing the Transaction: The Sponsor builds the final EIP-7702 transaction (type 0x04). This transaction is structured to be from the Sponsor, to the Sender, and contains the authorization_list and the execute calldata. The Sponsor then signs this complete transaction with their private key and broadcasts it to the network.

Transaction Results and Verification

The successful transaction hash was 0x6f8a54706c8d7b073e05bca95b77614aef620595f72b732d0669feab9f4b9181. Analysis on Sepolia Etherscan confirms the mechanism worked as intended:

This verification confirms that the Sender, who held no ETH, successfully initiated a token transfer, and the Sponsor paid the gas fee for that action.

Implications and Future of Sponsored Transactions

The successful implementation of EIP-7702's fee sponsorship has profound implications for the Web3 ecosystem:

However, this new power also introduces new considerations. Allowing EOAs to execute programmatic logic requires heightened security awareness. Users must be cautious about signing authorizations, and developers must guard against potential risks like replay attacks, where a signed authorization is maliciously reused. 👉 Explore more strategies for securing smart contract interactions

Frequently Asked Questions (FAQ)

What is EIP-7702?
EIP-7702 is an Ethereum Improvement Proposal that introduces a new transaction type. It allows a regular user account (EOA) to temporarily load smart contract code and act like a smart contract for a single transaction. This enables features like having someone else pay your gas fees (sponsorship), bundling actions, and setting advanced permissions.

How does transaction fee sponsorship work?
A sponsor sends a special EIP-7702 transaction. This transaction contains an authorization from the user (Sender) that allows their account to run a specific Delegation Contract. The sponsor's transaction pays the gas fee to execute this process. The loaded Delegation Contract then performs the actual action the user wanted, such as transferring tokens, all without the user needing any ETH.

Do I need a special wallet to use EIP-7702?
Yes, ultimately, wallet software needs to be updated to support creating and understanding EIP-7702 transactions. This includes the ability to create authorization requests for users to sign. As the standard gains adoption, major wallet providers are expected to integrate this functionality.

Is EIP-7702 live on the Ethereum mainnet?
EIP-7702 was implemented on the Ethereum mainnet in May 2025 as part of the Pectra upgrade. This means the core functionality is active and available for developers to build upon.

What are the security risks of authorization lists?
The main risk involves signing a malicious authorization. If a user signs an authorization for a harmful contract, that contract could perform unintended actions with the user's assets when sponsored. Users should only sign authorizations for transactions and contracts they fully trust. Wallets should implement clear UX to highlight what is being authorized.

Can any smart contract be a Delegation Contract?
Technically, yes, any contract can be specified in the authorization_list. However, the contract must have an interface that the transaction's calldata expects to call (like an execute function). For security and predictability, standardized and audited delegation contract designs will likely become common.