debug_traceTransaction

The debug_traceTransaction method returns the full trace of a transaction that has already been executed and included in a block. This method provides comprehensive debugging information including all internal calls, opcode execution, gas consumption at each step, and storage modifications.

This method is essential for post-mortem analysis of transactions, identifying bugs in smart contracts, and understanding complex transaction flows involving multiple contract interactions. Developers can use it to debug failed transactions, optimize gas usage, analyze reentrancy patterns, trace internal function calls, and understand exactly how a transaction executed at the EVM level. The configurable tracer options allow focusing on specific aspects of execution while minimizing overhead.

This method is available only on the full archive node.

Parameters

parameter	type	description
transactionHash	string (required)	The hash of the transaction to trace (32-byte hex string with 0x prefix)
traceConfig	object (optional)	Configuration object to customize the trace output

Trace Config Properties:

property	type	description
tracer	string (optional)	The type of tracer: 'callTracer' for call tree, 'prestateTracer' for state diff, '4byteTracer' for method signatures, or custom JavaScript tracer code
timeout	string (optional)	Maximum time allowed for the trace operation (e.g., '10s'). Defaults to '5s'
disableStorage	boolean (optional)	Set to true to disable storage capture, significantly reducing trace size and improving performance
disableMemory	boolean (optional)	Set to true to disable memory capture in the trace
disableStack	boolean (optional)	Set to true to disable stack capture in the trace
enableMemory	boolean (optional)	Set to true to enable memory capture (opposite of disableMemory)
enableReturnData	boolean (optional)	Set to true to enable capturing return data from calls

Return Object

The method returns detailed trace information with structure depending on the tracer used:

With default tracer:

gas – number: Total gas used by the transaction

failed – boolean: Whether the transaction failed mc39

returnValue – string: The return data from the transaction execution

structLogs – array: Array of opcode execution steps, where each step contains:

pc – number: Program counter position

op – string: Opcode name (PUSH1, ADD, SSTORE, etc.)

gas (per step) – number: Remaining gas before executing this opcode

gasCost – number: Gas cost of this opcode

depth – number: Call depth

stack – array: The EVM stack state

memory – array: The memory state

storage – object: Storage changes

With callTracer:

type – string: The type of the call (CALL, CREATE, DELEGATECALL, STATICCALL, etc.)

from – string: The address initiating the call

to – string: The address receiving the call

value – string: The value transferred in wei (hex)

gas – string: The gas provided for the call (hex)

gasUsed – string: The gas actually consumed (hex)

input – string: The input data sent with the call

output – string: The output data returned from the call

error – string: Error message if the call failed

calls – array: Array of nested internal calls made during execution, each with the same structure

Request Example

Request

Response Example

Response