trace_replayTransaction

Note

Served only when trace is named in --http.api or --ws.api; see Enabling Namespaces.

Replays a mined transaction and returns the trace types requested: the call frames, the executed instructions, the state changes, or any combination. The node re-executes the transaction’s block up to and including the transaction. A transaction the node does not know fails with -32001 and the message transaction not found.

Traces cover the block’s transactions only. The system calls a block runs before its transactions (EIP-4788 beacon root, EIP-2935 block hashes) and the epoch-closing system calls (applyIncentives and concludeEpoch) are not transactions, so no tracer shows them.

Parameters

DATA, 32 Bytes - The transaction hash.

Array - The trace types to return, any of "trace", "vmTrace" and "stateDiff".

Returns

Object - The requested traces:

output: DATA - The return data of the top-level call; 0x for a plain transfer.
stateDiff: Object - With stateDiff requested, the state changes keyed by account address; otherwise null. Each account has balance, code, nonce and storage (keyed by slot). Each value is "=" when unchanged, {"+": value} when created, {"-": value} when removed, or {"*": {"from": old, "to": new}} when changed.
trace: Array - With trace requested, the call frames, top-level first; otherwise []. Each frame has type, action, error (only when the frame failed), result, subtraces and traceAddress, with the meanings trace_transaction gives them, and no block or transaction fields. The top-level frame’s action.gas and result.gasUsed leave out the intrinsic gas, so for a plain transfer with a 21,000 gas limit both are 0x0.
vmTrace: Object - With vmTrace requested, the instructions the top-level call executed; otherwise null. It has code (DATA, the code that ran) and ops, one entry per instruction with cost (Number, its gas cost), pc (Number, the program counter), ex (its effects: used, push for the stack items it pushed, mem for a memory write and store for a storage write), sub (the nested vmTrace of a CALL or CREATE, or null), and, when present, op (the opcode name) and idx.

Example

Request

curl http://localhost:8545 \
 -X POST \
 -H "Content-Type: application/json" \
 --data '{"jsonrpc":"2.0","method":"trace_replayTransaction","params":["0xa794c7eb915c26fdb77242159053c1a36241bcd016b671fb07abe3fa9050805e",["trace"]],"id":1}'

Result

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "output": "0x",
    "stateDiff": null,
    "trace": [
      {
        "type": "call",
        "action": {
          "from": "0xb14d3c4f5fbfbcfb98af2d330000d49c95b93aa7",
          "callType": "call",
          "gas": "0x0",
          "input": "0x",
          "to": "0x0000000000000000000000000000000000000000",
          "value": "0x64"
        },
        "result": {
          "gasUsed": "0x0",
          "output": "0x"
        },
        "subtraces": 0,
        "traceAddress": []
      }
    ],
    "vmTrace": null
  }
}