• INTRO

Notes: OpenZeppelin, Factory Contracts, and Delegatecall

1. OpenZeppelin Libraries

• OpenZeppelin provides battle-tested Solidity libraries for common patterns (ERC standards, ownership, access control, etc.).
• Key benefits:
  • Security (avoids common bugs).
  • Reusable components.
  • Upgradability support (via proxy contracts).

1.1 Upgradeable Contracts

• Upgradeable contracts separate storage and logic.
• Logic is implemented in a logic contract (V1, V2…).
• Storage is maintained in a proxy contract.
• Proxy uses delegatecall to forward calls to the current logic contract.
• Advantages:
  • Users interact with the same address even after upgrades.
  • Allows adding/changing functionality without redeploying everything.

Key OpenZeppelin Tools:

• @openzeppelin/contracts-upgradeable
• ERC1967Proxy (upgradable proxy)
• Initializable (replaces constructor for proxies)