Crowdfill Marketplace

A decentralized OTC marketplace for ERC20 tokens with partial fill support.

Features

• Create and fill orders for ERC20 tokens
• Partial fill support
• Platform fee mechanism
• Order management (close/cancel)
• Emergency pause functionality
• Gas-optimized design

Contract Architecture

Crowdfill.sol

Main marketplace contract that handles:

• Order creation and filling
• Partial fills tracking
• Fee collection
• Order management

TestToken.sol

Simple ERC20 token for testing purposes.

Development

Prerequisites

• Node.js
• npm
• Hardhat
• MetaMask

Setup

1. Install dependencies:

npm install

2. Create .env file:

PRIVATE_KEY=your_metamask_private_key
SEPOLIA_URL=your_alchemy_sepolia_url
ETHERSCAN_API_KEY=your_etherscan_api_key

Testing

npx hardhat test

Deployment

npx hardhat run scripts/deploy.js --network sepolia

Contract Interaction

Creating an Order

// Approve tokens first
await token.approve(crowdfill.address, amount);
// Create order
await crowdfill.createOrder(token.address, amount, price);

Filling an Order

// Fill order with ETH
await crowdfill.fillOrder(orderId, amount, { value: price * amount });

Closing an Order

// Close order and get remaining tokens back
await crowdfill.closeOrder(orderId);

Security

• ReentrancyGuard for fill operations
• Pausable for emergency stops
• Ownable for admin functions
• Gas optimizations for cost efficiency