debug_traceCall

The debug_traceCall method executes a call without creating a transaction on the blockchain and returns detailed trace information about the execution. This allows developers to simulate and debug contract calls on the Kaia network before actually sending them.

This method is invaluable for pre-execution debugging, gas estimation validation, testing contract interactions without spending KAIA, and understanding complex call sequences. Developers can use it to debug contract calls before committing them to the blockchain, identify potential revert reasons, analyze internal function calls, optimize gas usage by examining execution traces, test different parameter combinations, and simulate calls at specific block heights to understand historical behavior. The ability to trace calls without state changes makes this perfect for safe testing and debugging.

This method is available only on the full archive node.

Parameters

parameter	type	description
transaction	object (required)	Transaction call object with fields like from, to, gas, gasPrice, value, and data
blockParameter	string (required)	Block number in hex format (e.g., '0x10d4f') or one of the string tags: 'latest', 'earliest', or 'pending'
traceConfig	object (optional)	Configuration object to customize the trace output

Transaction Object Properties:

property	type	description
from	string (optional)	Address the transaction is sent from (20 bytes)
to	string (required)	Address the transaction is directed to (20 bytes)
gas	string (optional)	Gas provided for the transaction execution (hex)
gasPrice	string (optional)	Gas price in wei (hex)
value	string (optional)	Value transferred in wei (hex)
data	string (optional)	Hash of the method signature and encoded parameters

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
disableMemory	boolean (optional)	Set to true to disable memory capture
disableStack	boolean (optional)	Set to true to disable stack capture

Return Object

The method returns detailed trace information with structure depending on the tracer used, following the same format as debug_traceTransaction.

Request Example

Request

Response Example

Response