debug_storageRangeAt - Ethereum

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

This method returns a range of storage slots from a specific contract at a specific block. Given a contract address and starting storage key hash, returns the next N slots along with a continuation cursor. Used for exhaustive storage-layout inspection during contract analysis, forensics, and archival research.

Parameters

Parameter	Type	Required	Description
blockHash	string	Yes	32-byte block hash
txIndex	integer	Yes	Transaction index within the block to snapshot storage at
address	string	Yes	20-byte contract address
startKey	string	Yes	Hex-encoded starting storage-key hash
maxResults	integer	Yes	Maximum number of slots to return in this page

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_storageRangeAt",
    "params": [
        "0x9ec8e2f6b78d8f5f2ac3e5d61b0d38d4d5a8f0e7c8b5a2f9d3e6c1b7a4d0f2e5c",
        0,
        "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2",
        "0x0000000000000000000000000000000000000000000000000000000000000000",
        10
    ],
    "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_storageRangeAt',
    params: [
        "0x9ec8e2f6b78d8f5f2ac3e5d61b0d38d4d5a8f0e7c8b5a2f9d3e6c1b7a4d0f2e5c",
        0,
        "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2",
        "0x0000000000000000000000000000000000000000000000000000000000000000",
        10
    ],
    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_storageRangeAt',
        'params': [
        "0x9ec8e2f6b78d8f5f2ac3e5d61b0d38d4d5a8f0e7c8b5a2f9d3e6c1b7a4d0f2e5c",
        0,
        "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2",
        "0x0000000000000000000000000000000000000000000000000000000000000000",
        10
    ],
        '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_storageRangeAt",
            "params": [
        "0x9ec8e2f6b78d8f5f2ac3e5d61b0d38d4d5a8f0e7c8b5a2f9d3e6c1b7a4d0f2e5c",
        0,
        "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2",
        "0x0000000000000000000000000000000000000000000000000000000000000000",
        10
    ],
            "id": "getblock.io"
        }))
        .send()
        .await?
        .json::<Value>()
        .await?;
    
    println!("Result: {}", response["result"]);
    Ok(())
}

Response

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": {
        "storage": {
            "0x290decd9548b62a8d60345a988386fc84ba6bc95484008f6362f93160ef3e563": {
                "key": "0x0000000000000000000000000000000000000000000000000000000000000000",
                "value": "0x000000000000000000000000000000000000000000000000000000000000000a"
            }
        },
        "nextKey": "0xb10e2d527612073b26eecdfd717e6a320cf44b4afac2b0732d9fcbe2b7fa0cf6"
    }
}

Response Parameters

Parameter	Type	Description
jsonrpc	string	JSON-RPC protocol version ("2.0")
id	string	Request identifier matching the request
result.storage	object	Map of storage-key-hash → {key, value} entries
result.nextKey	string	Continuation cursor for the next page (null when the range is exhausted)

Use Cases

• Exhaustive Storage Inspection: Enumerate all storage slots of a contract for reverse-engineering unknown storage layouts

• Forensic Analysis: Snapshot a contract's complete storage at the time of an exploit for post-mortem

• Mapping Enumeration: Iterate through all keys of a Solidity mapping when the key set isn't known in advance

Error Handling

Error Code	Message	Description
-32601	Method not found	debug module not enabled — Dedicated Node tier required
-32602	Invalid params	Block hash, address, or start key is malformed
-32603	Internal error	Node failed to enumerate storage (often indicates state pruning at the requested block)

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 range = await provider.send('debug_storageRangeAt', [
    '0x9ec8e2f6b78d8f5f2ac3e5d61b0d38d4d5a8f0e7c8b5a2f9d3e6c1b7a4d0f2e5c',
    0,
    '0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2',
    '0x0000000000000000000000000000000000000000000000000000000000000000',
    10
]);
console.log('Slots returned:', Object.keys(range.storage).length);

Viem

viem-example.js

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

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

const range = await client.request({
    method: 'debug_storageRangeAt',
    params: [
        '0x9ec8e2f6b78d8f5f2ac3e5d61b0d38d4d5a8f0e7c8b5a2f9d3e6c1b7a4d0f2e5c', 0, '0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2',
        '0x' + '0'.repeat(64), 10
    ],
});
console.log('Slots:', Object.keys(range.storage).length);