Local Fork RPC Request Recorder-and-Replay Tool

WHAT IT DOES

This tool connects to your EVM wallet and enables recording and replaying of RPC requests against local forks. It reads RPC request logs, transaction receipts, and call traces from local fork test runs, then replays them against a forked network for testing and debugging. The tool supports both read-only requests (eth_call, eth_getBalance) and transaction submissions (eth_sendTransaction), allowing developers to capture and reproduce complex interaction sequences.

HOW TO USE

Connect your Web3 wallet using the Connect button. Enter the fork RPC URL in the Fork RPC URL field—this should point to a local fork (e.g., Hardhat, Ganache, or Alchemy fork). Optionally, specify a block number to fork from. In the Requests field, enter a JSON array of RPC requests you want to record or replay. Click "Record Requests" to execute the requests against the fork and capture the results. Click "Replay Requests" to replay the requests against the fork, signing transactions when needed. Click "Load Sample" to populate fields with example requests. Results appear in the Results card with a summary of requests and a detailed log of each request and response.

TECHNICAL MECHANISM: FORK-BASED RPC REQUEST RECORDING AND REPLAY

The tool uses ethers.js to connect to a forked RPC endpoint. For recording, it executes each RPC request using the appropriate ethers provider method (getBalance, getCode, call, etc.) and captures the result. For replay, it supports read-only requests and transaction submissions. For eth_sendTransaction, the tool uses the connected wallet's signer to sign and send the transaction, waiting for confirmation. Each request and response is logged with success/failure status. The tool formats responses for display, truncating long values for readability. The replay process is sequential to maintain transaction ordering and avoid nonce conflicts.

WHAT IT CANNOT SEE

This tool cannot record RPC requests without an active local fork or proxy—the fork RPC must be running and accessible. It cannot replay requests that depend on specific chain state that has changed—state differences between recording and replay may cause different results. It cannot capture all network-level interactions (e.g., latency, ordering)—the tool only records request/response pairs. It relies on fork configuration and may not work with all RPC providers—some providers may not support fork simulation. It cannot guarantee replay consistency if contract state differs from recording time—state may have changed between recording and replay.

PLEASE NOTE

This tool signs transactions for replay—ensure you trust the fork environment. All data is processed in-memory and never persists. The tool supports EVM chains only—Ethereum, Polygon, BSC, Arbitrum, Optimism, Avalanche, Base, and Fantom. Recording and replay require an active fork RPC endpoint—consider using Hardhat, Foundry, or Tenderly for forking capabilities. Replayed transactions will consume gas on the fork—use test tokens or fork balances.