Bridge Contract Tester

WHAT IT DOES

Bridge Contract Tester lets you simulate calls to bridge contracts to test verification and relay functions. You provide the bridge contract address on the current chain, source and target chain IDs, a test message payload (or use a default), and select a function to test (verify, verifyMessage, isValidMessage, or relay). The tool constructs a call to the bridge contract with a generated message hash and dummy proof data, then executes a read-only call to check if the function succeeds. This is essential for developers auditing bridge contracts, testing integration before deployment, or debugging cross-chain message flows. It reads the current network chain ID from your wallet provider to ensure queries are directed to the correct chain.

HOW TO USE

Connect your wallet using the "Connect" button (required for RPC access). Select the target network (Ethereum Mainnet, Sepolia, Polygon, BSC, Arbitrum, Optimism, and testnets are supported). Enter the bridge contract address, source and target chain IDs, and optionally a test message payload (as hex). Select the function to test from the available options. Click "Test bridge" — the tool will generate a message hash, create a dummy proof, and call the selected function on the bridge contract. Results show whether the call succeeded, the message hash used, and any return values or errors. The entire operation is read-only — no transactions are signed or sent.

TECHNICAL MECHANISM

The tool builds a contract interface for the selected function using a minimal ABI. It generates a message hash from the provided payload (or a default test message) using keccak256. A dummy Merkle proof (32 bytes of zeros) is used as placeholder proof data. The tool then encodes the function call with the generated parameters and uses provider.call to execute a read-only simulation. For view functions (verify, verifyMessage, isValidMessage), this returns the boolean result. For the relay function, the tool simulates the call without actually executing state changes. The tool uses ethers.js v5.7.2 to interact with the contract via the wallet's provider. All calls are static — no state is modified.

WHAT IT CANNOT SEE

The tool cannot verify if the bridge contract is the correct one for the given source/target chain pair. It cannot simulate bridge calls that require state changes or signature validation without proper credentials (e.g., valid signatures, real Merkle proofs). It cannot detect if the bridge is actually deployed or functional on the target chain. It is limited by RPC provider availability and the specific bridge implementation's logic. It cannot test bridges that require actual cross-chain finality or off-chain relayer confirmation. It cannot verify messages from non-EVM chains. It cannot test functions that require complex proof structures beyond a simple dummy proof.

PLEASE NOTE

This tool is for educational and analytical purposes. The dummy proof used in tests will not pass actual verification on production bridges. Always use real proofs for actual verification. The tool does not persist any data; all state is lost on page reload. EVM chains only.