Smart contracts are programs stored on a blockchain that automatically execute when conditions are met.
- **Self-executing**: Run automatically when triggered
- **Immutable**: Can't be changed once deployed
- **Transparent**: Code is public and verifiable
- **Trustless**: No intermediary needed
1. Developer writes contract code
2. Code is deployed to blockchain
3. Contract gets a unique address
4. Users interact by sending transactions
5. Contract executes logic automatically
Token Creation: ERC-20 tokens, NFTs
DeFi: Lending, trading, yield
DAOs: Governance voting
Gaming: In-game assets, rewards
Solidity: Ethereum, most popular
Vyper: Python-like, for Ethereum
Rust: Solana, Cosmos
Move: Sui, Aptos
Smart contracts handle real money. Bugs are expensive.
- Reentrancy attacks
- Integer overflow
- Access control issues
- Oracle manipulation
Even if you don't code, you can:
- Check if contract is verified on Etherscan
- Look for audit reports
- See if source code is readable
- Check admin/owner permissions
Start with:
- CryptoZombies (game-based learning)
- Solidity by Example
- Hardhat/Foundry tutorials