solidity

name: solidity description: Solidity smart contract development for Ethereum and EVM chains. Use for .sol files.

Solidity

Solidity is the primary language for the Ethereum Virtual Machine (EVM). v0.8.28 (2025) focuses on transient storage (tstore) and gas optimization via IR.

When to Use

• Ethereum/L2s: Developing for Optimism, Arbitrum, Base.
• DeFi: Writing logic for tokens, AMMs, and lending.
• NFTs: ERC-721 and ERC-1155 contracts.

Core Concepts

Gas

Every operation costs ETH. Optimization is critical.

Modifiers

Reusable checks. modifier onlyOwner { ... }.

Events

Logging on the blockchain. emit Transfer(from, to, value).

Best Practices (2025)

Do:

• Use Foundry: The 2025 standard for testing (Solidity-based tests).
• Use Custom Errors: error InsufficientBalance(); is cheaper than string requires.
• Use OpenZeppelin: Don't roll your own crypto/auth logic.

Don't:

• Don't ignore reentrancy: Use ReentrancyGuard or Checks-Effects-Interactions pattern.

References

• Solidity Documentation