Cross-Contract Call Trace Visualizer

WHAT IT DOES

Cross-Contract Call Trace Visualizer is a developer-focused tool that visualizes cross-contract call traces from Ethereum transactions. It takes a transaction hash and optional contract ABI from the user, then fetches the transaction receipt and logs via eth_getTransactionReceipt. The tool analyzes the logs to build a hierarchical call tree showing which contracts called which functions, with indentation levels indicating call depth. When a contract ABI is provided, the tool decodes function names and event signatures from the log data, making the trace more human-readable. The call tree is displayed with color-coded nodes showing contract addresses and function names, along with call data previews. The trace can be exported as JSON for further analysis. This enables developers and auditors to understand the flow of cross-contract calls in complex transactions, identify potential issues, and debug contract interactions.

HOW TO USE

Connect your wallet to the target EVM chain. Enter the transaction hash into the input field. Optionally, paste the contract ABI (JSON format) to enable decoding of function names and event signatures. Click "Trace transaction" to fetch the transaction and generate the call trace. The tool will display a summary including the transaction details (from, to, block, status) and a hierarchical call tree showing each cross-contract call with its address, function name, and depth level. The trace can be copied or downloaded as JSON for further analysis.

TECHNICAL NOTE: LOG-BASED CALL TRACE CONSTRUCTION

The tool builds call traces by analyzing the transaction receipt logs. It processes each log in order, using the log address and topic signatures to identify contract calls. When an ABI is provided, the tool uses ethers.js to decode function signatures and event names from the log data. The call hierarchy is constructed using a simple heuristic: consecutive logs from the same address are treated as siblings at the same depth, while logs from different addresses indicate a deeper call. For transactions without internal trace data (debug_traceTransaction not available), the tool provides a simulated trace based on the available logs. The tool also detects the root call from the transaction's `to` field and the calldata.

WHAT IT CANNOT SEE

The tool cannot trace transactions that are not available on the RPC node. It is limited to the accuracy of the provided ABI; without the correct ABI, function names cannot be decoded. It cannot decode calls without the correct ABI or if the ABI is incomplete. The tool is limited by debug_traceTransaction availability on the RPC endpoint; the current implementation uses logs for tracing and may not capture all internal calls. It cannot visualize cross-contract calls without internal trace data. The tool cannot trace transactions on non-EVM chains.

PLEASE NOTE

This tool is designed exclusively for EVM-compatible chains (Ethereum, Polygon, BNB Chain, Arbitrum, Optimism, Avalanche C-Chain, etc.). It does not support non-EVM blockchains. The trace is based on transaction logs and may not include all internal calls, especially those that do not emit logs. For full internal trace data, use an RPC endpoint that supports debug_traceTransaction. The tool is read-only and does not modify any state. The tool provides no warranty that the trace is complete or accurate; users should verify with additional tools if needed.