arb_getL1Confirmations - Robinhood

Example code for the arb_getL1Confirmations JSON-RPC method. Complete guide to using the arb_getL1Confirmations JSON-RPC method in GetBlock.io Web3 documentation.

Returns the number of L1 (Ethereum) block confirmations for a given L2 block hash. This is an Arbitrum-Orbit-canonical method for tracking how deeply an L2 block has been settled on L1. A high confirmation count indicates the block is unlikely to be reorged, providing stronger settlement guarantees than the finalized tag on the L2 side alone.

Arbitrum-Orbit-specific method. This method is part of the Arbitrum Nitro namespace and is not available on generic EVM chains. It exposes L1 settlement information specific to Arbitrum Orbit L2s. ethers.js and viem do not provide typed wrappers — use the raw request interface as shown in the SDK Integration tabs.

Parameters

Parameter	Type	Required	Description
blockHash	DATA (32 bytes)	Yes	L2 block hash to check L1 confirmations for

Request Example

cURL

curl --location --request POST 'https://shared.us-east-1.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "arb_getL1Confirmations",
    "params": [
        "0x8b5c6f1a9e8d7c6b5a4f3e2d1c0b9a8e7f6d5c4b3a2b1f9e8d7c6b5a4f3e2d1c"
    ],
    "id": "getblock.io"
}'

JavaScript (Axios)

import axios from 'axios';

const data = JSON.stringify({
    "jsonrpc": "2.0",
    "method": "arb_getL1Confirmations",
    "params": [
        "0x8b5c6f1a9e8d7c6b5a4f3e2d1c0b9a8e7f6d5c4b3a2b1f9e8d7c6b5a4f3e2d1c"
    ],
    "id": "getblock.io"
});

const config = {
    method: 'post',
    url: 'https://shared.us-east-1.getblock.io/<ACCESS-TOKEN>/',
    headers: {
        'Content-Type': 'application/json'
    },
    data: data
};

axios(config)
    .then(response => console.log(JSON.stringify(response.data, null, 2)))
    .catch(error => console.log(error));

Python (Requests)

import requests
import json

url = "https://shared.us-east-1.getblock.io/<ACCESS-TOKEN>/"

payload = json.dumps({
    "jsonrpc": "2.0",
    "method": "arb_getL1Confirmations",
    "params": [
        "0x8b5c6f1a9e8d7c6b5a4f3e2d1c0b9a8e7f6d5c4b3a2b1f9e8d7c6b5a4f3e2d1c"
    ],
    "id": "getblock.io"
})

headers = {
    'Content-Type': 'application/json'
}

response = requests.post(url, headers=headers, data=payload)
print(response.text)

Rust (Reqwest)

use reqwest::Client;
use serde_json::json;

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

    let payload = json!({
        "jsonrpc": "2.0",
        "method": "arb_getL1Confirmations",
        "params": [
                "0x8b5c6f1a9e8d7c6b5a4f3e2d1c0b9a8e7f6d5c4b3a2b1f9e8d7c6b5a4f3e2d1c"
        ],
        "id": "getblock.io"
});

    let response = client
        .post("https://shared.us-east-1.getblock.io/<ACCESS-TOKEN>/")
        .header("Content-Type", "application/json")
        .json(&payload)
        .send()
        .await?;

    let result: serde_json::Value = response.json().await?;
    println!("{:#?}", result);

    Ok(())
}

Response Example

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": "0x12"
}

Response Parameters

Field	Type	Description
result	QUANTITY	Number of L1 block confirmations (hex). 0x0 if the block hasn't been posted to L1 yet

Use Cases

• Bridging and withdrawal flows that require confirmed L1 settlement

• High-value transaction settlement verification

• Cross-chain messaging systems that need to wait for L1 finality before acting

• Auditing tools tracking L1 posting cadence

Error Handling

Status Code	Error Message	Cause
403	Forbidden	Missing or invalid <ACCESS-TOKEN>
-32602	Invalid params	Request parameters are missing or malformed
-32603	Internal error	Server-side error while processing the request
429	Too Many Requests	Rate limit exceeded for your plan
-32602	Invalid block hash	Block hash is not a valid 32-byte hex string, or block does not exist

SDK Integration

ethers.js

import { ethers } from 'ethers';

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

// Arbitrum-Orbit-specific methods don't have ethers wrappers — use .send():
const result = await provider.send('arb_getL1Confirmations', ["0x8b5c6f1a9e8d7c6b5a4f3e2d1c0b9a8e7f6d5c4b3a2b1f9e8d7c6b5a4f3e2d1c"]);
console.log(result);

viem

import { createPublicClient, http } from 'viem';

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

// Arbitrum-Orbit-specific methods need the raw request transport:
const result = await client.request({
    method: 'arb_getL1Confirmations',
    params: ["0x8b5c6f1a9e8d7c6b5a4f3e2d1c0b9a8e7f6d5c4b3a2b1f9e8d7c6b5a4f3e2d1c"]
});
console.log(result);