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

#	Name	Type	Required	Description
1	`transactionHash`	string	Yes	Hash of the transaction to replay.
2	`traceTypes`	array	Yes	One or more of `"trace"`, `"vmTrace"`, `"stateDiff"`. At least one value is required.

Response

Type	Description
object	`{output, trace?, stateDiff?, vmTrace?}` — `trace` is the call tree, `stateDiff` maps each affected address to balance/nonce/code/storage diffs using `=` (unchanged), `+` (created), `-` (deleted), `*{from,to}` (modified), `vmTrace` is the Parity-format opcode trace.

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

Code	Message	Cause
`-32601`	`Method not found`	trace namespace not enabled or not supported by this client (primarily OpenEthereum/Nethermind/Erigon).
`-32602`	`Invalid params`	Transaction hash is missing/malformed or traceTypes is empty or contains unknown values.
`-32000`	`transaction not found`	Transaction does not exist or archive trace data is unavailable for that block.

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