Delegatable

The solidity maintenance has moved to this dedicated repository

An abstract solidity contract that any contract can easily integrate to add a ton of improvements to that contract's user and developer experience for all of its functions:

• Allow users to sign "invocations" instead of transactions, which bring lots of benefits.
• Invocations bring the full user-readability of signTypedData for all of that app's operations.
• Support for MetaTransactions
• Support for batched operations: Many actions in one transaction, and potentially lower gas costs.
• Support for signing multiple actions that aren't blocked by each other, so an urgent transaction isn't blocked by the low nonce of a low-stakes low-gas bid transaction.
• Support for signing commitments that can be lazily submitted to the blockchain later.
• Allow users to sign offchain messages that delegate authority to perform any action they can perform, along with an open-ended system for adding restrictions to that delegation, including revocation.
• Allow the holder of any delegation to issue a delegation from it, also with an off-chain signature and no up-front gas.
• Allows creating invite links to users who don't have accounts set up yet, by signing delegations to a key you send to them.

You can read about the theory behind this library here.

Integration in a Solidity project

pragma solidity ^0.8.13;

import "./Delegatable.sol";

contract YourContract is Delegatable {

  constructor(string memory name) Delegatable(name, "1") {}

  function _msgSender () internal view override(Delegatable, Context) returns (address sender) {
    if(msg.sender == address(this)) {
      bytes memory array = msg.data;
      uint256 index = msg.data.length;
      assembly {
        // Load the 32 bytes word from memory with the address on the lower 20 bytes, and mask those.
        sender := and(mload(add(array, index)), 0xffffffffffffffffffffffffffffffffffffffff)
      }
    } else {
      sender = msg.sender;
    }
    return sender;
  }

}

To use this in your own contract, follow these simple steps:

• inherit your contract from contracts/Delegatable.sol.
• Your constructor will need to pass the Delegatable class a name for your contract, and a version string, per EIP 712.
• Add our sample _msgSender() method to your contract, as seen in our sample contract.
• If you are inheriting from any contracts that use msg.sender to identify a user, you should now use the _msgSender() method instead, to benefit from this framework. Conveniently, it seems that most OpenZeppelin libraries already use an internal _msgSender() implementation, and so overriding it as shown should be enough to use those libraries.

Integration into a web frontend

You can see a working web frontend at MobyMask.

I've started assembling a useful utility for managing memberships & delegations in JS as eth-delegatable-utils (npm, github)

These contracts should be compatible with any signer or wallet that supports signTypedData_v4, like MetaMask.

You will be calling the eth_signTypedData method with the V4 parameter, as seen in the test files.

How it's set up

A fork of Scaffold-ETH boilerplate

Currently most of the good stuff is going on in packages/hardhat.

everything you need to build on Ethereum! 🚀

🧪 Quickly experiment with Solidity using a frontend that adapts to your smart contract:

🏄‍♂️ Quick Start

Prerequisites: Node plus Yarn and Git

clone/fork 🏗 scaffold-eth:

git clone https://github.com/austintgriffith/scaffold-eth.git

install and start your 👷‍ Hardhat chain:

cd scaffold-eth
yarn install
yarn chain

in a second terminal window, start your 📱 frontend:

cd scaffold-eth
yarn start

in a third terminal window, 🛰 deploy your contract:

cd scaffold-eth
yarn deploy

🔏 Edit your smart contract YourContract.sol in packages/hardhat/contracts

📝 Edit your frontend App.jsx in packages/react-app/src

💼 Edit your deployment scripts in packages/hardhat/deploy

📱 Open http://localhost:3000 to see the app

📚 Documentation

Documentation, tutorials, challenges, and many more resources, visit: docs.scaffoldeth.io

🔭 Learning Solidity

📕 Read the docs: https://docs.soliditylang.org

📚 Go through each topic from solidity by example editing YourContract.sol in 🏗 scaffold-eth

• Primitive Data Types
• Mappings
• Structs
• Modifiers
• Events
• Inheritance
• Payable
• Fallback

📧 Learn the Solidity globals and units

🛠 Buidl

Check out all the active branches, open issues, and join/fund the 🏰 BuidlGuidl!

• 🚤 Follow the full Ethereum Speed Run

• 🎟 Create your first NFT

• 🥩 Build a staking smart contract

• 🏵 Deploy a token and vendor

• 🎫 Extend the NFT example to make a "buyer mints" marketplace

• 🎲 Learn about commit/reveal

• ✍️ Learn how ecrecover works

• 👩‍👩‍👧‍👧 Build a multi-sig that uses off-chain signatures

• ⏳ Extend the multi-sig to stream ETH

• ⚖️ Learn how a simple DEX works

• 🦍 Ape into learning!

💬 Support Chat

Join the telegram support chat 💬 to ask questions and find others building with 🏗 scaffold-eth!

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