Merkle Airdrop Smart Contract

This project demonstrates how to implement a smart contract for an airdrop that uses a Merkle tree for whitelisting addresses. The goal is to generate a Merkle root from a list of eligible addresses, implement a Solidity contract that verifies claims against this Merkle root, and manage the airdrop process.

Table of Contents

• Merkle Airdrop Smart Contract
  • Table of Contents
  • Overview
  • Prerequisites
  • Setup
  • Generating the Merkle Tree
  • Deploying the MerkleAirdrop Contract
  • Claiming the Airdrop
  • Testing
  • Assumptions and Limitations

Overview

This project consists of three main components:

1. Merkle Tree Generation: A script (merkle.js) to generate a Merkle root from a CSV file containing addresses and their respective token amounts.
2. Solidity Smart Contract: A contract (MerkleAirdrop.sol) that allows users to claim tokens by providing a valid Merkle proof.
3. Testing: A test suite to ensure the correct functionality of the airdrop contract.

Prerequisites

Before getting started, ensure you have the following installed:

• Node.js (v14 or later)
• npm
• Hardhat (for testing and deployment)
• Solidity
• A code editor (e.g., Visual Studio Code)

Setup

1. Clone the repository:

   git clone https://github.com/Superior212/Airdrop-merkel-tree
   cd merkle-airdrop

2. Install the necessary dependencies:

   npm install

3. Prepare the CSV file:

   Ensure your CSV file containing addresses and token amounts is structured as follows:

   address,amount
   0x123...abc,100
   0x456...def,200
   

   Save this file as airdrop.csv in the project root directory.

Generating the Merkle Tree

To generate the Merkle tree:

1. Run the merkle.js script:

   node merkle.js

   This script reads the airdrop.csv file, hashes each entry, constructs a Merkle tree, and outputs the Merkle root. You can find the script in the scripts/ directory.

Deploying the MerkleAirdrop Contract

1. Deploy the contract:

   Using Hardhat, you can deploy the MerkleAirdrop.sol contract with the generated Merkle root. The deployment script can be found in the scripts/deploy.js file.

   To deploy:

   npx hardhat run scripts/deploy.js

Claiming the Airdrop

To claim tokens:

1. Generate the Merkle proof:

   Use the merkletreejs library to generate a proof for a specific address. Refer to the scripts/proofGenerator.js file for an example of how to generate a proof.

2. Claiming tokens:

   Users can interact with the deployed contract's claim function using a valid Merkle proof.

Testing

Testing is crucial to ensure the contract behaves as expected. The test suite includes cases for:

• Deploying the contract with a sample ERC20 token and Merkle root.
• Simulating valid and invalid claims.
• Ensuring correct handling of double claims and invalid proofs.

You can find the test cases in the test/MerkleAirdrop.test.js file. To run the tests:

npx hardhat test

Assumptions and Limitations

• The project assumes a basic understanding of Solidity, Merkle trees, and Hardhat.
• The Merkle tree is generated from a CSV file and assumes that all entries are valid.
• The contract does not include advanced security features like pausable functions or upgradability.