trace_replayTransaction

Replays a transaction on Ethereum and returns the requested traces.

Archive Node Required

This method requires an archive node. It is not available on full nodes.

Use Cases

• Transaction replay - Re-execute a transaction with full trace output
• State diff extraction - Get exact state changes from a transaction
• VM trace debugging - Get opcode-level execution details for DeFi protocols (60% market share), NFT marketplaces, DAOs, and enterprise dApps

Parameters

Parameter	Type	Required	Description
txHash	DATA	Yes	32-byte transaction hash
traceTypes	Array	Yes	Trace types: ["trace"], ["vmTrace"], ["stateDiff"], or combinations

Request

{
  "jsonrpc": "2.0",
  "method": "trace_replayTransaction",
  "params": ["0x42690cc81dfd7f6a5ebc973fd8c4912e6068df47646c665a1b54fae904b0470a", ["trace"]],
  "id": 1
}

Code Examples

cURL

curl -X POST https://api-ethereum-mainnet.n.dwellir.com/YOUR_API_KEY \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "trace_replayTransaction",
    "params": ["0x42690cc81dfd7f6a5ebc973fd8c4912e6068df47646c665a1b54fae904b0470a", ["trace"]],
    "id": 1
  }'

JavaScript

import { JsonRpcProvider } from 'ethers';

const provider = new JsonRpcProvider('https://api-ethereum-mainnet.n.dwellir.com/YOUR_API_KEY');

const result = await provider.send('trace_replayTransaction', [
  '0x42690cc81dfd7f6a5ebc973fd8c4912e6068df47646c665a1b54fae904b0470a',
  ['trace']
]);
console.log('Trace:', result.trace.length, 'entries');
console.log('State diff:', result.stateDiff ? 'present' : 'not requested');

Python

from web3 import Web3

w3 = Web3(Web3.HTTPProvider('https://api-ethereum-mainnet.n.dwellir.com/YOUR_API_KEY'))

result = w3.provider.make_request('trace_replayTransaction', [
    '0x42690cc81dfd7f6a5ebc973fd8c4912e6068df47646c665a1b54fae904b0470a',
    ['trace']
])
trace = result['result']
print(f'Trace entries: {len(trace["trace"])}')

Related Methods

• trace_replayBlockTransactions - Replay all transactions in a block
• trace_transaction - Get traces without replay
• trace_block - Get all traces in a block