Gasless Adapter for Any ERC20

This repository provides a generic Gasless Adapter module that adds ERC2612 (permit) and ERC3009 (gasless transfers) support to any standard ERC20 token.

• Core base contract: GaslessAdapterBase
• Standard adapter implementation: StandardGaslessAdapter (deployed via factory)
• Factory contract: GaslessAdapterFactory (deploys adapters)
• Standalone extensions: ERC2612, ERC3009

The design follows EIP-712 and exposes a full ERC20 interface plus:

• ERC2612: permit, nonces, DOMAIN_SEPARATOR
• ERC3009: transferWithAuthorization, receiveWithAuthorization, cancelAuthorization, authorizationState

Quick Start: Deploy via Factory

Deploy a gasless adapter for your ERC20 using the provided Foundry scripts.

Supported Networks

Currently the repository ships with a pre-deployed factory on:

• Base Sepolia
  • Chain ID: 84532
  • Factory address: 0x5e5E52fb594e5F98BD582b309d16FAE02D1e9032

You can deploy additional factories on other networks if needed.

1. Deploy an Adapter via Factory (Foundry)

Use the DeployAdapterViaFactory script. Required environment variables:

• PRIVATE_KEY: Deployer private key
• RPC_URL: RPC endpoint for the target network
• FACTORY_ADDRESS: Factory contract address (see above)
• UNDERLYING_TOKEN: Underlying ERC20 token address
• TOKEN_NAME: EIP712 domain name
• TOKEN_VERSION: EIP712 domain version
• OWNER: Owner address for the adapter

Example (Base Sepolia):

export PRIVATE_KEY=your-private-key
export RPC_URL=https://sepolia.base.org
export FACTORY_ADDRESS=0x5e5E52fb594e5F98BD582b309d16FAE02D1e9032
export UNDERLYING_TOKEN=0x...        # your ERC20 token
export TOKEN_NAME="MyToken Adapter"
export TOKEN_VERSION="1"
export OWNER=0x...                   # adapter owner

forge script script/DeployAdapterViaFactory.s.sol:DeployAdapterViaFactory \
  --rpc-url $RPC_URL \
  --broadcast

The script will print the deployed adapter address to the console.

If you prefer to deploy the factory yourself on another network, use:

export PRIVATE_KEY=your-private-key
export RPC_URL=<your-rpc-url>

forge script script/GaslessAdapterFactory.s.sol:GaslessAdapterFactoryDeploy \
  --rpc-url $RPC_URL \
  --broadcast

Then pass the new factory address as FACTORY_ADDRESS when running DeployAdapterViaFactory.

Integrating Your ERC20 with the Adapter

You can integrate in two ways:

1. Use Factory + SDK - Deploy via factory.
2. Write your own adapter contract that inherits GaslessAdapterBase - For custom logic.

1. Writing Your Own Adapter on GaslessAdapterBase

If you need custom logic, inherit GaslessAdapterBase directly:

• Implement _getUnderlyingToken() to return the underlying ERC20 address.
• Optionally:
  • inherit Pausable and override _requireNotPaused() to enforce pause,
  • inherit Ownable or AccessControl to restrict admin operations.

The signature verification and allowance handling for ERC2612/3009 are already implemented in GaslessAdapterBase, ERC2612, and ERC3009.

EIP-712 Configuration

The EIP-712 domain is configured through the GaslessAdapterBase constructor:

• tokenName: used as the domain name.
• tokenVersion: used as the domain version.

Frontends and wallets must use these values when constructing EIP-712 payloads for:

• ERC2612 Permit:
  • Type hash: Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)
• ERC3009 transfers:
  • TransferWithAuthorization
  • ReceiveWithAuthorization
  • CancelAuthorization

Use the adapter’s DOMAIN_SEPARATOR() and nonces(owner) view functions when building client-side signing payloads.

Foundry Commands

This repository uses Foundry for building and testing.

• Build

forge build

• Test

forge test

• Format

forge fmt

• Gas Snapshots

forge snapshot

• Anvil

anvil