NFT Sword Game Contracts

A blockchain-based game system where players can mint sword NFTs and import/export them between the game world and their wallet.

Overview

This project consists of two main smart contracts:

• Sword: An ERC721 NFT contract for minting and managing sword tokens
• World: A game world contract that can hold NFTs on behalf of players

Prerequisites

• Node.js v18+
• npm/yarn
• A .env file with:

  SEPOLIA_URL=your_sepolia_rpc_url
  PRIVATE_KEY=your_wallet_private_key
  

Installation

Install dependencies

npm install

Run test suite

npx hardhat test

Deployment

The contracts are deployed using Hardhat Ignition modules. To deploy:

Deploy to Sepolia testnet

npx hardhat ignition deploy ./ignition/modules/SwordModule.ts
npx hardhat ignition deploy ./ignition/modules/WorldModule.ts

Contract Interactions

Several scripts are provided to interact with the deployed contracts:

Check sword NFT balance

npx hardhat run scripts/checkSwords.ts

Import sword to game world

npx hardhat run scripts/importSword.ts

Export sword to game world

npx hardhat run scripts/exportSword.ts

Contract Addresses (Sepolia)

• Sword: 0xb17ef91a01F269229296b42Fd1d82768443fAD18
• World: 0x266B0D35AF7dc889E9bE144ce41EB08568421803

Testing

The test suite covers:

• Minting new sword NFTs
• Transferring ownership
• Importing/exporting between wallet and game world
• Authorization checks

Run tests with:

npx hardhat test

Development

The project uses:

• Hardhat for development environment and testing
• OpenZeppelin for NFT implementation
• TypeScript for deployment scripts and tests
• Hardhat Ignition for deployment management

License

ISC

Current Implementation and Limitations

Current Working

The system currently works as follows:

1. Users can mint sword NFTs
2. To move a sword into a game world:
   • Owner must first approve the World contract to handle their NFT
   • Owner then calls importItem on the World contract
3. To retrieve a sword from a game world:
   • Original owner calls exportItem on the World contract
   • NFT is transferred back to the owner

Known Limitations

The main limitation is the approval workflow:

• Each World contract requires separate approval for NFT transfers
• For N different worlds, a user needs to make N separate approval transactions
• This becomes costly and cumbersome when:
  • Moving items between multiple worlds
  • Implementing cross-game compatibility
  • Creating new game worlds that want to accept existing swords

🤝 Call for Contributions

We're looking for innovative solutions to improve the NFT transfer workflow. Some areas to consider:

1. Universal Approval System

   • How can we implement a single approval that works across multiple world contracts?
   • What security considerations need to be addressed?

2. Smart Contract Architecture

   • Could a registry or proxy pattern help?
   • How to maintain individual world autonomy while reducing approval friction?

3. Gas Optimization

   • How can we minimize the number of transactions needed?
   • What patterns could reduce gas costs for users?

How to Contribute

1. Fork the repository
2. Create a new branch for your feature
3. Implement your solution
4. Add tests and documentation
5. Submit a Pull Request with:
   • Detailed description of your approach
   • Gas cost analysis
   • Security considerations
   • Any tradeoffs made

We welcome all creative solutions! Please ensure your PR includes:

• Clean, well-documented code
• Comprehensive test coverage
• Gas optimization analysis
• Security considerations

Join the discussion in our Issues section!