debug_getBadBlocks - Blast

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

This method returns blocks the client recently rejected as invalid, with the reason. It is a Dedicated Node tier diagnostic used to investigate consensus or propagation issues.

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

Parameters

This method does not require any parameters. Send the request with an empty params array.

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_getBadBlocks",
    "params": [],
    "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_getBadBlocks',
    params: [],
    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_getBadBlocks',
        'params': [],
        '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_getBadBlocks",
            "params": [],
            "id": "getblock.io"
        }))
        .send()
        .await?
        .json::<Value>()
        .await?;

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

Response

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": []
}

Response Parameters

Parameter	Type	Description
jsonrpc	string	JSON-RPC protocol version ("2.0")
id	string	Request identifier matching the request
result	array	Array of rejected block records (empty if none)

Use Cases

• Consensus Debugging: Inspect blocks the node rejected and why

• Incident Analysis: Correlate bad blocks with a network event

• Client Diagnostics: Detect propagation of malformed blocks

• Monitoring: Alert when bad blocks appear on an endpoint

Error Handling

Error Code	Message	Description
-32603	Internal error	The node failed to return bad block records
-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.eu-central-1.getblock.io/<ACCESS-TOKEN>/');

const bad = await provider.send('debug_getBadBlocks', []);

Viem

viem-example.js

import { createPublicClient, http } from 'viem';

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

const bad = await client.request({ method: 'debug_getBadBlocks' });