Multi-Chain Contract Version Sync Checker

WHAT IT DOES

Multi-Chain Contract Version Sync Checker is a read-only developer tool that verifies that the same contract version is deployed across multiple EVM-compatible chains. It reads contract bytecode via eth_getCode on each specified chain, generates a version fingerprint from the bytecode, compares them against the reference chain, and provides a detailed synchronization report. The tool helps developers ensure that all deployed instances of a contract are running the same version, detect version drift across chains, validate that upgrades have been applied consistently, and maintain cross-chain deployment parity. It is essential for projects deploying the same contract across multiple networks.

HOW TO USE

Connect your EVM-compatible wallet via the BGWallet bridge and select the network where your contract is deployed (this becomes the reference chain). Enter the contract address, optionally provide an expected version label, and specify a comma-separated list of chains to check (e.g., ethereum,polygon,bsc,arbitrum,optimism,avalanche). Click "Check Version Sync" to fetch bytecode from the reference chain and all specified chains, generate version hashes, and compare them. Results include a summary of all checked chains, a comparison table showing chain name, version hash, block number, and status (Synced/Out of Sync/Error), an overall sync status, and a summary of synced, out-of-sync, and error chains. The tool also provides a reference version hash and detailed recommendations if mismatches are found. All analysis is read-only—no signatures or transactions are submitted.

TECHNICAL MECHANISM

The tool uses ethers.js v5.7.2 to fetch contract bytecode via provider.getCode(address) from multiple chains. It uses the current provider for the reference chain, and creates independent JsonRpcProvider instances for each target chain using built-in RPC endpoints. For each chain, it retrieves the bytecode, generates a version fingerprint by extracting the first 64 characters of the bytecode (after the 0x prefix) to create a consistent identifier for version comparison, and fetches the current block number for context. The tool compares each chain's version fingerprint against the reference chain's fingerprint. Results are categorized as "Synced" (fingerprint matches), "Out of Sync" (fingerprint differs), or "Error" (failed to fetch). The overall sync status is determined by whether all chains match the reference version. The tool includes built-in RPC endpoints for supported chains and provides clear error messages for unknown chains or failed connections.

WHAT IT CANNOT SEE

This tool has fundamental limitations that users must understand. It cannot automatically determine which version is "correct" or should be the reference—the tool uses the current chain as the reference and does not validate which version is intended. It cannot detect version differences that do not affect bytecode (e.g., comments, whitespace, variable name changes)—the tool only compares bytecode, not source code. It cannot guarantee that matching bytecode means identical behavior across chains with different EVM implementations—some chains have subtle differences that could affect execution. It cannot automatically resolve version conflicts or perform upgrades—the tool is read-only and only reports differences. It cannot detect version differences in libraries or dependencies not included in the contract bytecode. It cannot analyze version history without user-provided version mapping. It cannot detect changes in storage layout or initialization parameters that don't affect bytecode. The tool's RPC endpoints are public and may be rate-limited. The version fingerprint is a heuristic and may not be unique across different contract versions.

PLEASE NOTE

This tool only supports EVM-compatible blockchains (Ethereum, Polygon, BSC, Avalanche C-Chain, Optimism, Arbitrum, and their testnets). Solana, Tron, Starknet, SUI, TON, Aptos, Bitcoin, Cosmos, and XRP are not supported. The tool is free, open-source, requires no API keys, and uses the wallet's native provider for all read operations. Always verify the RPC endpoints used are reliable and that the contract address is correct on each target chain.