debug_traceTransaction - Filecoin

Example code for the debug_traceTransaction JSON RPC method. Complete guide on how to use debug_traceTransaction JSON RPC in GetBlock Web3 documentation.

This method replays a transaction and returns a detailed execution trace, including opcode-level steps or a structured call trace depending on the tracer. It is used to debug transaction execution and reverts.

Parameters

Parameter	Type	Required	Description
transactionHash	string	Yes	32-byte hash of the transaction to trace
options	object	No	Tracer options, such as the tracer name and its configuration

Options Object

Field	Type	Required	Description
tracer	string	No	Tracer to use, such as callTracer or prestateTracer
timeout	string	No	Maximum trace duration, such as "10s"

Request

cURL

curl --location --request POST 'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "debug_traceTransaction",
    "params": ["0x4a7b0c3d6e9f2a5b8c1d4e7f0a3b6c9d2e5f8a1b4c7d0e3f6a9b2c5d8e1f4a7b", {"tracer": "callTracer"}],
    "id": "getblock.io"
}'

Axios

example.js

const axios = require('axios');

const response = await axios.post('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/', {
    jsonrpc: '2.0',
    method: 'debug_traceTransaction',
    params: ["0x4a7b0c3d6e9f2a5b8c1d4e7f0a3b6c9d2e5f8a1b4c7d0e3f6a9b2c5d8e1f4a7b", {"tracer": "callTracer"}],
    id: 'getblock.io'
}, {
    headers: { 'Content-Type': 'application/json' }
});

console.log(response.data.result);

Request

example.py

import requests

response = requests.post(
    'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/',
    headers={'Content-Type': 'application/json'},
    json={
        'jsonrpc': '2.0',
        'method': 'debug_traceTransaction',
        'params': ["0x4a7b0c3d6e9f2a5b8c1d4e7f0a3b6c9d2e5f8a1b4c7d0e3f6a9b2c5d8e1f4a7b", {"tracer": "callTracer"}],
        'id': 'getblock.io'
    }
)

print(response.json())

Rust

example.rs

use reqwest::Client;
use serde_json::{json, Value};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let client = Client::new();

    let response = client
        .post("https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/")
        .header("Content-Type", "application/json")
        .json(&json!({
            "jsonrpc": "2.0",
            "method": "debug_traceTransaction",
            "params": ["0x4a7b0c3d6e9f2a5b8c1d4e7f0a3b6c9d2e5f8a1b4c7d0e3f6a9b2c5d8e1f4a7b", {"tracer": "callTracer"}],
            "id": "getblock.io"
        }))
        .send()
        .await?
        .json::<Value>()
        .await?;

    println!("Result: {}", response["result"]);
    Ok(())
}

Response

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": {
        "from": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045",
        "to": "0x60E1773636CF5E4A227d9AC24F20fEca034ee25A",
        "value": "0xde0b6b3a7640000",
        "gas": "0x5208",
        "gasUsed": "0x5208",
        "input": "0x",
        "output": "0x",
        "type": "CALL",
        "calls": []
    }
}

Response Parameters

Parameter	Type	Description
jsonrpc	string	JSON-RPC protocol version ("2.0")
id	string	Request identifier matching the request
result	object	Execution trace, shaped by the selected tracer

callTracer Object

Field	Type	Description
from	string	Address that initiated the call
to	string	Address that received the call
gasUsed	string	Gas used by the call frame
output	string	Return data of the call
calls	array	Nested internal calls

Use Cases

• Revert Debugging: Trace why a transaction reverted

• Internal Calls: Reconstruct internal contract calls with callTracer

• MEV Analysis: Inspect execution paths of complex transactions

• Gas Profiling: Attribute gas usage across call frames

Error Handling

Error Code	Message	Description
-32602	Invalid params	The transaction hash is not a valid 32-byte hex string
-32603	Internal error	The node failed to read the transaction

Web3 Integration

Ethers.js

ethers-example.js

const { ethers } = require('ethers');

const provider = new ethers.JsonRpcProvider('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/');

const trace = await provider.send('debug_traceTransaction', ['0x4a7b0c3d6e9f2a5b8c1d4e7f0a3b6c9d2e5f8a1b4c7d0e3f6a9b2c5d8e1f4a7b', { tracer: 'callTracer' }]);
console.log(trace);

Viem

viem-example.js

import { createPublicClient, http } from 'viem';
import { filecoin } from 'viem/chains';

const client = createPublicClient({ chain: filecoin, transport: http('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/') });

const trace = await client.request({ method: 'debug_traceTransaction', params: ['0x4a7b0c3d6e9f2a5b8c1d4e7f0a3b6c9d2e5f8a1b4c7d0e3f6a9b2c5d8e1f4a7b', { tracer: 'callTracer' }] });
console.log(trace);