upgrade-solidity-contracts
Solidity Upgrades
Contents
- Proxy Patterns Overview
- Upgrade Restrictions Between Major Versions (v4 → v5)
- Writing Upgradeable Contracts
- Hardhat Upgrades Workflow
- Foundry Upgrades Workflow
- Handling Upgrade Validation Issues
- Upgrade Safety Checklist
Proxy Patterns Overview
| Pattern | Upgrade logic lives in | Best for |
|---|---|---|
UUPS (UUPSUpgradeable) |
Implementation contract (override _authorizeUpgrade) |
Most projects — lighter proxy, lower deploy gas |
| Transparent | Separate ProxyAdmin contract |
When admin/user call separation is critical — admin cannot accidentally call implementation functions |
| Beacon | Shared beacon contract | Multiple proxies sharing one implementation — upgrading the beacon atomically upgrades all proxies |
More from openzeppelin/openzeppelin-skills
setup-solidity-contracts
Set up a Solidity smart contract project with OpenZeppelin Contracts. Use when users need to: (1) create a new Hardhat or Foundry project, (2) install OpenZeppelin Contracts dependencies for Solidity, (3) configure remappings for Foundry, or (4) understand Solidity import conventions for OpenZeppelin.
242develop-secure-contracts
Develop secure smart contracts using OpenZeppelin Contracts libraries. Use when users need to integrate OpenZeppelin library components — including token standards (ERC20, ERC721, ERC1155), access control (Ownable, AccessControl, AccessManager), security primitives (Pausable, ReentrancyGuard), governance (Governor, timelocks), or accounts (multisig, account abstraction) — into existing or new contracts. Covers pattern discovery from library source, CLI contract generators, and library-first integration. Supports Solidity, Cairo, Stylus, and Stellar.
221setup-stellar-contracts
Set up a Stellar/Soroban smart contract project with OpenZeppelin Contracts for Stellar. Use when users need to: (1) install Stellar CLI and Rust toolchain for Soroban, (2) create a new Soroban project, (3) add OpenZeppelin Stellar dependencies to Cargo.toml, or (4) understand Soroban import conventions and contract patterns for OpenZeppelin.
114upgrade-stellar-contracts
Upgrade Stellar/Soroban smart contracts using OpenZeppelin's upgradeable module. Use when users need to: (1) make Soroban contracts upgradeable via native WASM replacement, (2) use Upgradeable or UpgradeableMigratable derive macros, (3) implement atomic upgrade-and-migrate patterns with an Upgrader contract, (4) ensure storage key compatibility across upgrades, or (5) test upgrade paths for Soroban contracts.
106upgrade-cairo-contracts
Upgrade Cairo smart contracts using OpenZeppelin's UpgradeableComponent on Starknet. Use when users need to: (1) make Cairo contracts upgradeable via replace_class_syscall, (2) integrate the OpenZeppelin UpgradeableComponent, (3) understand Starknet's class-based upgrade model vs EVM proxy patterns, (4) ensure storage compatibility across upgrades, (5) guard upgrade functions with access control, or (6) test upgrade paths for Cairo contracts.
97setup-stylus-contracts
Set up a Stylus smart contract project with OpenZeppelin Contracts for Stylus on Arbitrum. Use when users need to: (1) install Rust toolchain and WASM target for Stylus, (2) create a new Cargo Stylus project, (3) add OpenZeppelin Stylus dependencies to Cargo.toml, or (4) understand Stylus import conventions and storage patterns for OpenZeppelin.
92