Contract Chain ID Mismatch Detector

WHAT IT DOES

Contract Chain ID Mismatch Detector is a read-only tool that analyzes contract addresses to detect whether they are deployed on the expected chain or if there is a chain ID mismatch. It reads contract address, deployed chain ID (from contract creation), current network chain ID, bytecode hash, contract creation transaction, deployment block, contract metadata, ENS or reverse lookup records, block explorer chain identification, chain-specific deployment patterns, and known cross-chain contract addresses. The tool then presents this data alongside an AI-generated explanation of whether the contract is on the expected chain, the risks of interacting with a contract on the wrong chain, and a warning if a mismatch is confirmed — helping you avoid potentially catastrophic errors when interacting with cross-chain contracts.

HOW TO USE

Connect your wallet using the BGWallet bridge and select your target network. Enter the contract address you want to check. Optionally specify an expected chain ID (defaults to the currently selected network). Click "Detect chain ID mismatch" to read on-chain data. The tool displays the contract address, expected chain ID, detected chain ID, match status (Match or Mismatch), and bytecode hash. Detailed information includes creation transaction, deployment block, contract metadata, ENS or reverse lookup records, block explorer chain identification, deployment pattern, and known cross-chain addresses. A prominent alert appears if a mismatch is detected. An AI explanation appears below the on-chain data, describing whether the contract is deployed on the expected chain, the risks of interacting with a contract on the wrong chain, and a warning if a mismatch is confirmed. The wallet's own signature step still protects you — this explanation is informational only and does not replace reviewing what you approve in your wallet.

TECHNICAL MECHANISM

The tool uses ethers.js v5.7.2 with the provider from the BGWallet bridge to read on-chain data from the contract you specify. No hardcoded contract addresses are used — you are always in control of which contract you trust. When detecting chain ID mismatches, the tool reads the deployed chain ID by analyzing the contract's creation transaction or by checking chain-specific metadata (e.g., via block explorer APIs or contract metadata), reads the current network chain ID via provider.getNetwork(), reads the bytecode hash via provider.getCode(contract) to compute the keccak256 hash for comparison, reads the contract creation transaction via provider.getTransactionReceipt() on the deployment transaction, reads the deployment block from the receipt, reads contract metadata from the block explorer API or chain-specific registries, reads ENS or reverse lookup records via the ENS resolver, reads block explorer chain identification via API or built-in chain IDs, identifies chain-specific deployment patterns by comparing the contract's bytecode and metadata against known patterns for that chain, and reads known cross-chain contract addresses from a local or API-based database. The tool fetches event logs by walking backwards in chunks and halving chunk size on failure, ensuring logs are properly read despite varying RPC limitations. The data is formatted and passed to the AI bridge via BGAI.generate() with a structured prompt that includes all the on-chain data read. The AI is instructed to detect whether the contract is deployed on the expected chain or if there is a chain ID mismatch, explain the risks of interacting with a contract on the wrong chain, and warn if the mismatch is confirmed — while stating plainly that it cannot detect contracts deployed via proxies that report a different chain ID, and cannot verify that the contract's behavior is identical across chains even if the bytecode matches. The AI response is capped at 1,024 tokens to ensure concise, focused mismatch assessments. All computed values are guarded against negative numbers — if a chain ID or block number appears invalid, the tool flags it rather than displaying nonsensical values.

WHAT IT CANNOT SEE

This tool cannot detect contracts deployed via proxies that report a different chain ID. It cannot verify that the contract's behavior is identical across chains even if the bytecode matches. It cannot detect malicious contracts that deliberately impersonate cross-chain deployments beyond bytecode comparison. The AI explanation is generated from on-chain data only and cannot detect proxy pattern implementation details, off-chain proxy logic, or intent behind cross-chain deployments. It cannot predict future chain ID changes, proxy upgrades, or cross-chain bridge failures. The tool does not continuously monitor the contract; each analysis is a snapshot at the time of the lookup. It cannot detect delayed proxy updates, off-chain chain ID mismatches, or stale metadata. The tool does not store any data persistently; all state is in-memory and resets on reload. The AI explanation is informational and does not constitute financial advice, legal advice, or a guarantee of contract safety or correct chain identification.

PLEASE NOTE

Contract Chain ID Mismatch Detector works exclusively with EVM-compatible chains. It requires a Web3 wallet (MetaMask or similar) and the BGWallet bridge. Explanations are AI-generated from data the app reads on-chain — always review what you are actually signing in your wallet before approving it. Always verify the contract address you are using — the tool does not validate or endorse any contracts. Interacting with a contract on the wrong chain carries significant risk including loss of funds, failed transactions, and unintended contract behavior. Use this tool as a guide only; always cross-check with the protocol's official documentation and block explorers for critical decisions. This is experimental software; use at your own risk.