ETH Token Recover

TokenRecover allows to recover any ERC20 or NFT (ERC721) token sent into the contract and send them to a receiver.

There are lots of tokens lost forever into Smart Contracts (see OMG token balances). Each Ethereum contract, as well as any EVM compatible contract, is a potential token trap for ERC20 or ERC721 tokens. They can't be recovered, so it means money losses for end users.

By using TokenRecover, any smart contract can offer users a robust solution for reclaiming mistakenly or erroneously sent tokens, enhancing the overall user experience and confidence in the decentralized ecosystem.

Install

npm install eth-token-recover

Recovers

The recover contracts define internal methods that can be used in derived contracts.

RecoverERC20

RecoverERC20.sol

Allows to recover any ERC20 token sent into the contract and send them to a receiver.

[!WARNING] It allows everyone to recover tokens. Access controls MUST be defined in derived contracts.

pragma solidity ^0.8.20;

import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";

abstract contract RecoverERC20 {
    function _recoverERC20(address tokenAddress, address tokenReceiver, uint256 tokenAmount) internal virtual {
        IERC20(tokenAddress).transfer(tokenReceiver, tokenAmount);
    }
}

RecoverERC721

RecoverERC721.sol

Allows to recover any ERC721 token sent into the contract and send them to a receiver.

[!WARNING] It allows everyone to recover tokens. Access controls MUST be defined in derived contracts.

pragma solidity ^0.8.20;

import {IERC721} from "@openzeppelin/contracts/token/ERC721/IERC721.sol";

abstract contract RecoverERC721 {
    function _recoverERC721(address tokenAddress, address tokenReceiver, uint256 tokenId, bytes memory data) internal virtual {
        IERC721(tokenAddress).safeTransferFrom(address(this), tokenReceiver, tokenId, data);
    }
}

Usage

The below contracts define high level code that can be inherited as is or extended to cover desired behaviors.

ERC20Recover

ERC20Recover.sol

Allows the contract owner to recover any ERC20 token sent into the contract and send them to a receiver.

[!IMPORTANT] This contract is Ownable and restricts access to recover method to owner only.

Use ERC20Recover

pragma solidity ^0.8.20;

import {ERC20Recover} from "eth-token-recover/contracts/ERC20Recover.sol";

contract MyContract is ERC20Recover {
    constructor(address initialOwner) ERC20Recover(initialOwner) {
        // your stuff
    }
    
    // your stuff
}

ERC721Recover

ERC721Recover.sol

Allows the contract owner to recover any ERC721 token sent into the contract and send them to a receiver.

[!IMPORTANT] This contract is Ownable and restricts access to recover method to owner only.

Use ERC721Recover

pragma solidity ^0.8.20;

import {ERC721Recover} from "eth-token-recover/contracts/ERC721Recover.sol";

contract MyContract is ERC721Recover {
    constructor(address initialOwner) ERC721Recover(initialOwner) {
        // your stuff
    }
    
    // your stuff
}

TokenRecover

TokenRecover.sol

Allows the contract owner to recover any ERC20 or ERC721 token sent into the contract and send them to a receiver.

[!IMPORTANT] This contract is Ownable and restricts access to recover methods to owner only.

Use TokenRecover

pragma solidity ^0.8.20;

import {TokenRecover} from "eth-token-recover/contracts/TokenRecover.sol";

contract MyContract is TokenRecover {
    constructor(address initialOwner) TokenRecover(initialOwner) {
        // your stuff
    }
    
    // your stuff
}

Examples

Contracts can be extended to add custom logic (e.g. to add custom roles or rules).

Add rules to high level

pragma solidity ^0.8.20;

import {TokenRecover} from "eth-token-recover/contracts/TokenRecover.sol";
import {MyDefinedRules} from "./MyDefinedRules.sol";

contract MyContract is TokenRecover, MyDefinedRules {
    constructor(address initialOwner) TokenRecover(initialOwner) {
        // your stuff
    }
    
    // your stuff

    function recoverERC20(address tokenAddress, address tokenReceiver, uint256 tokenAmount) public virtual override alsoMyRule {
        // your stuff
        
        super.recoverERC20(tokenAddress, tokenReceiver, tokenAmount);

        // your stuff
    }
}

Add rules to low level

pragma solidity ^0.8.20;

import {RecoverERC20} from "eth-token-recover/contracts/recover/RecoverERC20.sol";
import {MyDefinedRules} from "./MyDefinedRules.sol";

contract MyContract is RecoverERC20, MyDefinedRules {
    // your stuff

    function myRecoverERC20(address tokenAddress, address tokenReceiver, uint256 tokenAmount) public virtual onlyMyRule {
        // your stuff
        
        _recoverERC20(tokenAddress, tokenReceiver, tokenAmount);

        // your stuff
    }
}

Migrating from 4.x

[!WARNING] The TokenRecover constructor now requires an initialOwner parameter, making the ownership initialization explicit.

A contract inheriting from TokenRecover needs to be updated in the following way.

pragma solidity ^0.8.20;

import {TokenRecover} from "eth-token-recover/contracts/TokenRecover.sol";

contract MyContract is TokenRecover {
+   constructor(address initialOwner) TokenRecover(initialOwner) {
+       // your stuff
+   }
    
    // your stuff
}

[!WARNING] The v4.x (and earlier) TokenRecover::recoverERC20 method has been updated to accept the tokenReceiver address, the address that will receive the recovered token.

-function recoverERC20(address tokenAddress, uint256 tokenAmount) public virtual onlyOwner
+function recoverERC20(address tokenAddress, address tokenReceiver, uint256 tokenAmount) public virtual onlyOwner

Check the Backwards Compatibility section for additional details.

Backwards Compatibility

A backward compatible (legacy) version is available in the legacy folder.

TokenRecoverLegacy contract will:

• implicitly set the deployer as contract owner
• send recovered tokens to owner instead of providing an explicit receiver

To use TokenRecoverLegacy, a contract inheriting from TokenRecover needs to be updated in the following way

pragma solidity ^0.8.20;

-import {TokenRecover} from "eth-token-recover/contracts/TokenRecover.sol";
+import {TokenRecoverLegacy} from "eth-token-recover/contracts/legacy/TokenRecoverLegacy.sol";

-contract MyContract is TokenRecover {    
+contract MyContract is TokenRecoverLegacy {    
    // your stuff
}

[!CAUTION] TokenRecoverLegacy is a legacy version of TokenRecover that works as v4.x and earlier and MAY be removed in future releases.

We highly recommend to keep the code updated to use newer versions of the recover.

Documentation

• Solidity API

Code Analysis

• Control Flow
• Description Table
• Inheritance Tree
• UML

Development

Install dependencies

npm install

Compile

npm run compile

Test

npm test

Code Coverage

npm run coverage

Linter

Check Solidity files

npm run lint:sol

Check JS/TS files

npm run lint:js

Fix JS and Solidity files

npm run lint:fix

License

Code released under the MIT License.