Upgrade Simulation Dry-Run Tool

WHAT IT DOES

Upgrade Simulation Dry-Run Tool is a specialized security and developer tool that simulates proxy upgrades without executing them on-chain. It reads the current implementation address from the EIP-1967 implementation storage slot (0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc) using eth_getStorageAt, providing a baseline for comparison. The tool then retrieves the proxy's bytecode via eth_getCode to verify it follows a proxy pattern and confirms the proxy is properly deployed. It fetches the new implementation's bytecode and analyzes both implementations for code presence and basic structural compatibility. The tool reads state variables and storage slots to detect potential layout conflicts between current and new implementations. It also checks the proxy admin or owner address to confirm upgrade authority, reads chain state for block context, and reviews transaction history for upgrade events. All analysis is performed off-chain and read-only, providing a comprehensive risk assessment before any actual upgrade transaction is submitted.

HOW TO USE

Connect your wallet to the target EVM chain. Enter the proxy contract address and the new implementation address you want to test. Click "Simulate upgrade" to run the dry-run analysis. The tool will fetch and compare both implementations, checking for code presence, proxy pattern compliance, and basic storage layout compatibility. Results will display a detailed report including proxy status, current and new implementation addresses, code presence verification, storage compatibility assessment, and validation details for each check. A pass/fail status indicates whether the upgrade appears safe from a storage and deployment perspective. Review the results carefully before proceeding with an actual upgrade transaction.

TECHNICAL NOTE: MULTI-LAYER SIMULATION AND STORAGE ANALYSIS

The tool performs a three-layer simulation: first, it verifies the proxy contract's deployment status and EIP-1967 compliance by checking the implementation slot and bytecode presence. Second, it validates both the current and new implementations have deployed code, ensuring the upgrade target is valid. Third, it performs a basic storage layout comparison by analyzing the current state and detecting potential collisions. The tool reads the proxy's storage slots to map existing state variables and compares them against the new implementation's expected layout. It also checks for admin or owner address consistency to ensure upgrade authority is maintained. All RPC calls are chunked and backed off automatically to handle varying provider rate limits, ensuring reliable simulation even on public endpoints. The tool provides immediate feedback with color-coded pass/fail indicators and detailed validation breakdowns.

WHAT IT CANNOT SEE

The tool cannot simulate the full runtime behavior of the upgraded contract, including interactions with other contracts, external calls, or complex state transitions. It cannot detect logic errors that only manifest during actual execution, such as reentrancy vulnerabilities, arithmetic overflows, or permission issues. It cannot predict gas costs accurately beyond basic estimation, as actual gas usage depends on execution context. It cannot verify that the new implementation's storage layout is fully compatible beyond basic slot checks; deep compatibility analysis requires Solidity metadata and source code comparison. It cannot detect reinitialization failures or missing initializer functions that are required for the new implementation's proper setup. It cannot test upgrade functions that require specific call data or state conditions that exist only during live execution. The tool cannot simulate upgrades on non-EVM chains and cannot detect security vulnerabilities in the new implementation's source code or logic.

PLEASE NOTE

This tool is designed exclusively for EVM-compatible chains (Ethereum, Polygon, BSC, Arbitrum, Optimism, Avalanche C-Chain, etc.). It does not support non-EVM blockchains like Bitcoin, Solana, Cosmos, or Tron. This is a read-only simulation tool and does not submit any transactions. The simulation results are an indication of potential compatibility but do not guarantee upgrade safety. Always perform additional testing on testnet before executing upgrades on mainnet. The tool provides no warranty or guarantee of upgrade success; users are responsible for verifying all implementation details and testing thoroughly.