trace_replayTransaction

Give trace_replayTransaction the hash of a transaction that already landed on Ethereum, and the node re-runs it against the state that existed just before it executed, then returns whatever depth of detail you select. You choose any combination of three views: trace (the call tree), vmTrace (an opcode-by-opcode record), and stateDiff (every balance, nonce, code, and storage slot the transaction altered, marked with +, -, *, or =). It's the single-transaction member of the replay family on Ethereum mainnet (chain ID 1), where its block-wide sibling handles entire blocks. Replay requests go to https://ethereum.therpc.io/YOUR_API_KEY and require an archive node, since reconstructing the pre-transaction state means reaching back into history.

Use cases

• Reconstruct the exact storage writes a past transaction made. The stateDiff lists each touched slot with its before and after value, which is what forensic work on a hack or a mispriced trade depends on.
• Debug a revert by reading the state diff up to the failure point to pin down which storage slot or balance check tripped the transaction.
• Build a compliance audit trail: a per-transaction record of every ETH balance shift and storage mutation, sourced straight from the replayed execution rather than inferred from events.

Parameters

Response

Example request

1curl https://ethereum.therpc.io/YOUR_API_KEY \
2  -X POST \
3  -H "Content-Type: application/json" \
4  -d '{
5    "jsonrpc": "2.0",
6    "method": "trace_replayTransaction",
7    "params": [
8        "0x0000000000000000000000000000000000000000000000000000000000000000",
9        [
10          "trace"
11        ]
12      ],
13    "id": 1
14  }'

Try it live in the Ethereum playground.

Errors & troubleshooting

Common pitfalls

• vmTrace on a complex transaction (a multi-hop DEX route, a flash-loan unwind) generates an enormous opcode log. When you only need call structure or storage changes, stick to ["trace"] or ["stateDiff"].
• The method requires a trace-enabled archive node; the historical state needed for the replay isn't kept by a pruned full node.
• The vmTrace is Parity-format, not Geth's structLog. If you're migrating from debug_traceTransaction, expect a different schema and adjust your decoder accordingly.

Supported networks

• Mainnet — Chain ID: 1
• Sepolia — Chain ID: 11155111

See also

• trace_transaction
• trace_replayBlockTransactions
• trace_call
• debug_traceTransaction

1curl https://ethereum.therpc.io/YOUR_API_KEY \
2  -X POST \
3  -H 'Content-Type: application/json' \
4  -d '{"jsonrpc":"2.0","id":1,"method":"trace_replayTransaction","params":["0x0000000000000000000000000000000000000000000000000000000000000000",[]]}'