trace_transaction

Note

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

Returns every call frame of a mined transaction as a flat list of Parity-style traces, the top-level call first. The node re-executes the transaction’s block up to and including the transaction to build them.

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.

Returns

Array - The transaction’s traces, or null when the node does not know the transaction. Each trace is an object:

action: Object - What the frame did. For a call: from (DATA, 20 bytes, the caller), callType (call, callcode, delegatecall or staticcall), gas (QUANTITY, the gas available to the frame), input (DATA), to (DATA, 20 bytes) and value (QUANTITY, in wei). For a create: from, gas, init (DATA, the init code), value and creationMethod (create or create2). For a suicide (a SELFDESTRUCT): address, balance and refundAddress. The top-level frame’s gas is the transaction’s gas limit minus its intrinsic gas, so it is 0x0 for a plain transfer sent with a 21,000 gas limit.
blockHash: DATA, 32 Bytes - Hash of the block that holds the transaction.
blockNumber: Number - Number of that block, as a JSON number rather than a hex string.
error: String - The error the frame failed with. Absent when the frame succeeded.
result: Object - The frame’s outcome. For a call: gasUsed (QUANTITY) and output (DATA). For a create: address (DATA, 20 bytes, the new contract), code (DATA, the deployed code) and gasUsed. null for a suicide, and can be null for a frame that failed. The top-level frame’s gasUsed leaves out the intrinsic gas, so it is 0x0 for a plain transfer.
subtraces: Number - How many frames this frame called directly.
traceAddress: Array - The frame’s path in the call tree, as JSON numbers: [] for the top-level frame, [0] for its first child, [0, 1] for that child’s second child.
transactionHash: DATA, 32 Bytes - Hash of the transaction.
transactionPosition: Number - The transaction’s index in the block, as a JSON number.
type: String - The kind of frame: call, create or suicide.

Example

Request

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

Result

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": [
    {
      "action": {
        "from": "0xb14d3c4f5fbfbcfb98af2d330000d49c95b93aa7",
        "callType": "call",
        "gas": "0x0",
        "input": "0x",
        "to": "0x0000000000000000000000000000000000000000",
        "value": "0x64"
      },
      "blockHash": "0x1e0ed1376b6f8cc5deb9749a96c1207765ae9cd09ff46fe6200ca5b3f2913e8f",
      "blockNumber": 1,
      "result": {
        "gasUsed": "0x0",
        "output": "0x"
      },
      "subtraces": 0,
      "traceAddress": [],
      "transactionHash": "0xa794c7eb915c26fdb77242159053c1a36241bcd016b671fb07abe3fa9050805e",
      "transactionPosition": 0,
      "type": "call"
    }
  ]
}