ERC-7656

This is a reference implementation for the ERC-7656 standard taken from the Cruna Protocol implementation, which also has full coverage of the smart contracts.

The following bytecode:

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

has been deployed to erc7656.eth, i.e.:

0x7656f0fB4Ca6973cf99D910B36705a2dEDA97eA1

via Nick's Factory using the following salt:

0x765600000000000000000000000000000000000000000000000000000000cf7e

on the following mainnets:

Etherum
Polygon
BNB Chain
Base

and the following testnets:

Sepolia
Avalanche Fuji
Celo Alfajores
Base Sepolia
Arbitrum Sepolia
Polygon Amoy

The code has been verified on most mainnets.

Look at contracts/bytecode.json for the details.

To see if it has been deployed by others on other chains, look at https://blockscan.com/address/0x7656f0fB4Ca6973cf99D910B36705a2dEDA97eA1

Usage

Install it as a dependency

npm i erc7656 @openzeppelin/contracts

Make your nft able to deploy plugins

// SPDX-License-Identifier: MIT
// Compatible with OpenZeppelin Contracts ^5.0.0
pragma solidity ^0.8.20;

import {ERC721} from "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";
import {ERC7656DeployLib} from "erc7656/utils/ERC7656DeployLib.sol";

contract MyExpandableToken is ERC721, Ownable {
  
  error NotTheTokenOwner();
  
  constructor(address initialOwner) 
    ERC721("MyExpandableToken", "MET") 
    Ownable(initialOwner) {
  }

  function safeMint(address to, uint256 tokenId) public onlyOwner {
    _safeMint(to, tokenId);
  }

  function deployContractsOwnedByTheTokenId(
    address implementation,
    bytes32 salt,
    uint256 tokenId
  ) external payable virtual override {
    if (_msgSender() != ownerOf(tokenId)) revert NotTheTokenOwner();
    // passing address(0) as the registry address because we use the canonical one
    ERC7656DeployLib.deploy(implementation, salt, address(this), tokenId, address(0));
    
  }
  
}

To make your plugin extend exr7656/ERC7656Service.sol or erc7656/extensions/ERC7656ServiceExt.

Notice that anyone can deploy a service owned by a specific token, usign whatever salt they prefer. To avoid troubles and security issues, any initial setup must be designed so that, despite who is the deployer, the result is what is expected to be. For example, if a service must get some information from the token, it should be the service the one that queries the token, not the other way around. In other words, passing any parameter to the service during the deploying opens to the possibility of a malicious deployer to pass a different set of data causing the service to behave unexpectedly.

License

MIT

Copyright (C) 2023+ Cruna