debug_traceBlock - GIWA

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

This method replays and traces all transactions in an RLP-encoded block, returning per-transaction execution traces. It is a Dedicated Node tier method.

This method belongs to the debug namespace and is available on GetBlock Dedicated Nodes only. It is not served on shared endpoints.

Parameters

Parameter	Type	Required	Description
blockRlp	string	Yes	0x-prefixed RLP-encoded block
options	object	No	Tracer options (e.g. callTracer)

Request

cURL

curl --location --request POST 'https://shared.ap-southeast-1.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "debug_traceBlock",
    "params": ["0xf90211a0...", { "tracer": "callTracer" }],
    "id": "getblock.io"
}'

Axios

example.js

const axios = require('axios');

const response = await axios.post('https://shared.ap-southeast-1.getblock.io/<ACCESS-TOKEN>/', {
    jsonrpc: '2.0',
    method: 'debug_traceBlock',
    params: ['0xf90211a0...', { 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.ap-southeast-1.getblock.io/<ACCESS-TOKEN>/',
    headers={'Content-Type': 'application/json'},
    json={
        'jsonrpc': '2.0',
        'method': 'debug_traceBlock',
        'params': ['0xf90211a0...', { '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.ap-southeast-1.getblock.io/<ACCESS-TOKEN>/")
        .header("Content-Type", "application/json")
        .json(&json!({
            "jsonrpc": "2.0",
            "method": "debug_traceBlock",
            "params": ["0xf90211a0...", { "tracer": "callTracer" }],
            "id": "getblock.io"
        }))
        .send()
        .await?
        .json::<Value>()
        .await?;

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

Response

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": [
        {
            "result": {
                "type": "CALL",
                "from": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045",
                "to": "0x4200000000000000000000000000000000000006",
                "gasUsed": "0x5208",
                "calls": []
            }
        }
    ]
}

Response Parameters

Parameter	Type	Description
jsonrpc	string	JSON-RPC protocol version ("2.0")
id	string	Request identifier matching the request
result	array	Per-transaction execution traces

Use Cases

• Block Replay: Trace every transaction in a raw block

• Debugging: Investigate execution across a whole block

• Tracer Selection: Apply callTracer or a custom tracer to a block

• Analysis: Reconstruct call graphs from block execution

Error Handling

Error Code	Message	Description
-32602	Invalid params	Malformed RLP or tracer options
-32601	Method not found	The debug namespace is not enabled on this endpoint

Web3 Integration

Ethers.js

ethers-example.js

import { ethers } from 'ethers';

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

const traces = await provider.send('debug_traceBlock', ['0xf902...', { tracer: 'callTracer' }]);

Viem

viem-example.js

import { createPublicClient, http } from 'viem';

const client = createPublicClient({
  transport: http('https://shared.ap-southeast-1.getblock.io/<ACCESS-TOKEN>/')
});

const traces = await client.request({ method: 'debug_traceBlock', params: ['0xf902...', { tracer: 'callTracer' }] });