Solidity Contract Kit

A small, hand-written set of Solidity smart contract templates to fork and learn from. Nothing fancy or clever just clean, commented, well-tested starting points for the contracts people reach for most often. Everything runs on Hardhat and comes with a passing test suite.

⚠️ These are learning templates, not production code. They're here to read, fork, and build on. If you're going to deploy something that touches real money, get it professionally audited first.

What's in the box

Contract	Type	What it does
Token.sol	ERC-20	Mintable, burnable token with a fixed maximum supply.
NFTCollection.sol	ERC-721	Paid public minting, per-token metadata, a supply cap, and owner withdrawals.
Staking.sol	DeFi	Stake one token, earn another over time using reward-per-token accounting.
Vesting.sol	Tokenomics	Linear vesting with a cliff, for a single beneficiary.
MultiSigWallet.sol	Security	A minimal M-of-N multisig: submit → confirm → execute.

Where it makes sense, the contracts build on the audited OpenZeppelin libraries rather than reinventing them.

Getting started

You'll need Node.js (v18+). Then:

npm install      # pull down dependencies
npm run compile  # compile the contracts
npm test         # run the test suite (18 tests)

No configuration is needed to compile and test locally — Hardhat spins up an in-memory network for you.

Trying it on a testnet (Sepolia)

1. Copy the example env file and fill in your own values:

   cp .env.example .env

   SEPOLIA_RPC_URL=https://sepolia.infura.io/v3/YOUR_KEY
   PRIVATE_KEY=your_test_wallet_private_key
   ETHERSCAN_API_KEY=your_etherscan_key   # optional, only needed for verification
   

   Use a throwaway wallet funded from a Sepolia faucet. Never put a real private key in here, and never commit your .env.

2. Deploy:

   npm run deploy:sepolia

By default scripts/deploy.js deploys the Token contract as an example. Open it up and change a few lines to deploy any of the others.

Handy commands

npm run compile        # compile the contracts
npm test               # run the tests
npm run test:gas       # run the tests with a gas usage report
npm run node           # start a local Hardhat node
npm run deploy         # deploy to the local network
npm run deploy:sepolia # deploy to the Sepolia testnet

How the project is laid out

contracts/          Solidity sources
  Token.sol
  NFTCollection.sol
  Staking.sol
  Vesting.sol
  MultiSigWallet.sol
test/               Hardhat + Chai tests
  contracts.test.js
scripts/            Deployment scripts
  deploy.js
hardhat.config.js   Compiler + network config

A few notes worth reading

• NFTCollection doesn't refund overpayment. If a caller sends more than the mint price, the extra stays in the contract. Have your front-end send an exact amount, or add refund logic if you need it.
• Staking assumes it's been funded with reward tokens. Transfer enough reward tokens into the contract before people start staking, or claims will revert.
• MultiSigWallet fixes its owners and threshold at deploy time. That keeps it simple; if you need to rotate owners, you'll want to extend it.

Contributing

Pull requests are welcome new templates, gas optimizations, and extra tests especially. Fork it, build something, and open a PR.

License

MIT free to use, modify, and share.