debug_traceTransaction

Traces a transaction execution on Astar by transaction hash.

Archive Node Required

This method requires an archive node. It is not available on full nodes.

Use Cases

• Transaction debugging - Understand exactly what happened
• Failure analysis - Find where and why a transaction reverted
• Gas optimization - Analyze gas usage for cross-chain DeFi, multi-VM smart contracts, and XCM-enabled interoperability with Ethereum and Cosmos

Parameters

Parameter	Type	Required	Description
txHash	DATA	Yes	32-byte transaction hash
tracerConfig	Object	No	Tracer configuration

Tracer Options

• {} - Default opcode tracer (verbose)
• { tracer: "callTracer" } - Call tree tracer
• { tracer: "prestateTracer" } - Pre-state tracer

Request

{
  "jsonrpc": "2.0",
  "method": "debug_traceTransaction",
  "params": ["", {"tracer": "callTracer"}],
  "id": 1
}

Code Examples

cURL

curl -X POST https://api-astar.n.dwellir.com/YOUR_API_KEY \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "debug_traceTransaction",
    "params": ["", {"tracer": "callTracer"}],
    "id": 1
  }'

JavaScript

import { JsonRpcProvider } from 'ethers';

const provider = new JsonRpcProvider('https://api-astar.n.dwellir.com/YOUR_API_KEY');

const txHash = '';

// Call tracer - shows internal calls
const callTrace = await provider.send('debug_traceTransaction', [
  txHash,
  { tracer: 'callTracer' }
]);
console.log('Type:', callTrace.type);
console.log('From:', callTrace.from);
console.log('To:', callTrace.to);
console.log('Gas used:', parseInt(callTrace.gasUsed, 16));

// Prestate tracer - shows state before execution
const prestateTrace = await provider.send('debug_traceTransaction', [
  txHash,
  { tracer: 'prestateTracer' }
]);

Python

from web3 import Web3

w3 = Web3(Web3.HTTPProvider('https://api-astar.n.dwellir.com/YOUR_API_KEY'))

tx_hash = ''

# Call tracer
trace = w3.provider.make_request('debug_traceTransaction', [
    tx_hash,
    {'tracer': 'callTracer'}
])
print(f'Trace type: {trace["result"]["type"]}')
print(f'Gas used: {int(trace["result"]["gasUsed"], 16)}')

Related Methods

• debug_traceCall - Trace without executing
• debug_traceBlockByNumber - Trace entire block