upgrade-stylus-contracts

To upgrade Stylus contracts on Arbitrum, apply EVM proxy patterns like UUPS, Beacon, or Erc1967 to safely swap implementation logic without corrupting on-chain state. You enforce proxy-context via logic_flag and VERSION_NUMBER, guard upgrade functions with access control, and verify storage layout compatibility before swapping implementations.

Stylus storage compatibility verification checks that #[storage] layout rules are followed during contract upgrades to prevent slot collisions. The primary rule is to only append new fields to existing storage structs, ensuring that implementation swaps do not overwrite or misalign previously stored on-chain state.

Use UUPS proxies for Stylus upgrades when you want upgrade logic contained within the implementation contract itself, minimizing proxy size. Choose Beacon proxies when multiple Stylus contracts need to be upgraded simultaneously to the same new implementation through a single beacon contract.

Yes, you can migrate a Solidity implementation to Stylus behind an Erc1967 proxy. This requires verifying storage alignment between EVM and Stylus layouts, enforcing proxy-context via logic_flag, and performing controlled upgrades using access control to manage the implementation swap safely.

Yes, Stylus contracts require annual WASM reactivation procedures to maintain operational status on Arbitrum. Planning for yearly WASM reactivation is a necessary operational requirement when managing upgradeable Stylus contracts to ensure the implementation logic remains active and callable on-chain.

Test Stylus contract upgrade paths safely by deploying to a local Arbitrum devnet first. Verify storage compatibility, validate proxiable UUIDs, enforce proxy-context via logic_flag and VERSION_NUMBER, and check access control on upgrade_to_and_call functions before executing upgrades on mainnet.