EIP-7702 Implementation Guide: Build and Test Smart Accounts

Overview

EIP-7702 introduces transaction type 0x04 in Ethereum's Pectra upgrade, enabling externally owned accounts (EOAs) to temporarily function as smart contracts. This Account Abstraction advancement bridges EOAs and smart contracts, unlocking features like:

Batch transactions
Sponsored gas payments
Controlled access delegation

👉 Explore Ethereum's Pectra Upgrade

What You'll Learn

Implement 0x04 transactions with EOAs
Develop smart accounts using EIP-7702
Test transactions on local networks
Send EIP-7702 transactions with Viem

Requirements

Foundry installation
Basic Solidity/Foundry knowledge
Code editor (VS Code recommended)

EIP-7702 Transactions Explained

Key Features

Atomic Batch Operations: Combine token swaps/transfers in one TX
Temporary Delegation: Grant time-bound smart contract access
Gas Sponsorship: Allow third-party gas payment

Transaction Flow

User signs authorization message
Delegation designator links to implementation contract
Sponsor (optional) broadcasts transaction

// Sample Viem Implementation
const authorization = await walletClient.signAuthorization({ 
  contractAddress 
});

const hash = await walletClient.sendTransaction({
  authorizationList: [authorization],
  data: encodeFunctionData({/*...*/}),
  to: userAddress 
});

Testing EIP-7702 with Foundry

Project Setup

Install Foundry:

curl -L https://foundry.paradigm.xyz | bash
foundryup

Initialize Project:

forge init eip-7702-project
forge install OpenZeppelin/openzeppelin-contracts

Key Files:
- BatchCallAndSponsor.sol: Core logic
- BatchCallAndSponsor.t.sol: Test cases
- Deployment scripts

Implementation Highlights

function execute(Call[] calldata calls) external payable {
  require(msg.sender == address(this));
  _executeBatch(calls); 
}

function _executeBatch(Call[] calldata calls) internal {
  uint256 currentNonce = nonce++;
  // Replay protection
}

👉 View Complete Sample Project

FAQ

How does EIP-7702 improve wallet security?

It enables temporary smart contract functionality without exposing private keys, allowing features like transaction expiry dates.

Can EIP-7702 transactions be batched?

Yes - multiple operations can execute atomically in a single transaction.

Is mainnet deployment ready?

Yes, EIP-7702 is active on Ethereum mainnet and testnets like Sepolia post-Pectra upgrade.

References

Conclusion

EIP-7702 transforms EOAs into programmable wallets while maintaining security. Developers can now build:

Batch transaction systems
Gas sponsorship protocols
Recovery mechanisms

For updates:

🚀 Tip: Use forge script --broadcast to test deployments locally!