EIP-7702 Playground

This repository demonstrates EIP-7702: EOA Code Setting, a significant Ethereum upgrade introduced in Pectra upgrade.

View Asciinema demo

What is EIP-7702?

EIP-7702 allows Externally Owned Accounts (EOAs) to have code through a delegation mechanism. This brings smart contract capabilities to EOAs without requiring users to migrate to new accounts.

Key Features

• Set delegation code on EOAs
• Execute contract code in EOA context
• Maintain EOA transaction signing ability
• Support for cross-chain authorizations

Use Cases

• Transaction batching
• Gas sponsorship
• Granular permissions
• Account abstraction features

Sponsored Transfer Example

Our repository includes a complete example of gas sponsorship using EIP-7702:

// Alice authorizes Sponsor contract
bytes memory code = abi.encodePacked(hex"ef0100", address(sponsor));
vm.etch(alice, code);  // Sets delegation code

// Execute sponsored transfer where:
// 1. Relayer pays gas
// 2. Value comes from Alice
// 3. Bob receives the transfer
vm.prank(alice);
address(alice).call{value: 1 ether}(
    abi.encodeWithSelector(Sponsor.sponsoredTransfer.selector, bob)
);

Who Pays What

Party	Pays
Alice	Transfer value (e.g., 1 ETH)
Relayer	Gas fees
Bob	Nothing (recipient)

Technical Details

Delegation Format

bytes memory delegationCode = abi.encodePacked(
    hex"ef0100",        // EIP-7702 magic bytes
    address(contract)   // Target contract address
);

Example Usage

// Create a sponsor contract
Sponsor sponsor = new Sponsor();

// Set delegation on EOA (only works in Prague+)
bytes memory code = abi.encodePacked(hex"ef0100", address(sponsor));
vm.etch(eoa, code);  // Sets delegation code

// Any call to EOA is delegated to sponsor contract
// but executes in EOA's context

Testing

The repository includes tests that verify EIP-7702 functionality across different EVM versions:

# Should pass - Prague supports EIP-7702
FOUNDRY_PROFILE=prague forge test

# Alternatively
pnpm test

# Should fail - Shanghai doesn't support EIP-7702
FOUNDRY_PROFILE=shanghai forge test

# Alternatively
pnpm test:shanghai

Test Structure

• src/Sponsor.sol: Example contract for gas sponsorship
• src/EIP7702Demonstrator.sol: Helper contract for demonstrations
• test/SponsoredTransferTest.t.sol: Test suite showing sponsored transfers
• test/EIP7702Support.t.sol: Test suite for EVM version compatibility

Prerequisites

• Foundry v1.0 (learn more here)

Installation

forge install

Development

# Build
forge build

# Test with specific EVM version
FOUNDRY_PROFILE=prague forge test -vvv

Deploy

First, start a local Anvil node:

anvil

Then in a new terminal, deploy using one of the following commands:

Deploy with default (Prague) settings:

forge script script/Deploy.s.sol --broadcast --fork-url http://localhost:8545

Deploy with Prague profile explicitly:

FOUNDRY_PROFILE=prague forge script script/Deploy.s.sol --broadcast --fork-url http://localhost:8545

Deploy with Shanghai profile:

FOUNDRY_PROFILE=shanghai forge script script/Deploy.s.sol --broadcast --fork-url http://localhost:8545

For these scripts to work, you need to have a MNEMONIC environment variable set to a valid BIP39 mnemonic.

For instructions on how to deploy to a testnet or mainnet, check out the Solidity Scripting tutorial.

Key Differences: Prague vs Shanghai

Feature	Prague	Shanghai
Set EOA Code	✅	❌
Code Size	23 bytes	0 bytes
Delegation	Supported	Not Supported
Gas Sponsorship	✅	❌

Example Test Output

=== EIP-7702 Sponsored Transfer Details ===
Delegation code size: 23
Gas used: 68690
Value transferred: 1000000000000000000
Sender (Alice) balance change: 1000000000000000000
Recipient (Bob) balance change: 1000000000000000000

Support

Feel free to reach out to Julien through:

• Element: @julienbrg:matrix.org
• Farcaster: julien-
• Telegram: @julienbrg
• Twitter: @julienbrg
• Discord: julienbrg
• LinkedIn: julienberanger