> ## Documentation Index
> Fetch the complete documentation index at: https://docs.chainstack.com/llms.txt
> Use this file to discover all available pages before exploring further.

# debug_getModifiedAccountsByHash | Arbitrum

Arbitrum API method that retrieves a list of accounts that were modified in a specific block, identified by the block's hash. This method compares the state tries between the specified block and its parent to find all accounts with changed state.

<Note>
  Learn how to [deploy a node](/docs/debug-and-trace-apis#arbitrum) with the debug and trace API methods enabled.
</Note>

<Warning>
  This method is available for post-Nitro blocks only (block 22,207,815 and later). For pre-Nitro blocks, use the `arbtrace_*` methods instead.
</Warning>

<Check>
  **Get your own node endpoint today**

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  You can sign up with your GitHub, X, Google, or Microsoft account.
</Check>

## Parameters

* `startHash` — the hash of the block for which to retrieve modified accounts. When only this parameter is provided, the method returns accounts modified in this single block (compared to its parent).
* `endHash` — (optional) the hash of the end block. When provided, the method returns accounts modified between the `startHash` block and the `endHash` block.

## Response

* `result` — an array of account addresses that were modified in the specified block or range.

## `debug_getModifiedAccountsByHash` code examples

<CodeGroup>
  ```javascript ethers.js theme={"system"}
  const ethers = require('ethers');
  const NODE_URL = "YOUR_CHAINSTACK_ENDPOINT";
  const provider = new ethers.JsonRpcProvider(NODE_URL);

  const getModifiedAccounts = async (blockHash) => {
    const result = await provider.send("debug_getModifiedAccountsByHash", [blockHash]);
    console.log(result);
  };

  getModifiedAccounts("0x5765eab677d93b81a1c29de804e115d0e4db8dd40e0deabcf187e4e0d047c758");
  ```

  ```python web3.py theme={"system"}
  from web3 import Web3
  node_url = "YOUR_CHAINSTACK_ENDPOINT"
  web3 = Web3(Web3.HTTPProvider(node_url))

  block_hash = "0x5765eab677d93b81a1c29de804e115d0e4db8dd40e0deabcf187e4e0d047c758"
  result = web3.provider.make_request('debug_getModifiedAccountsByHash', [block_hash])
  print(result)
  ```
</CodeGroup>

## Use case

The `debug_getModifiedAccountsByHash` method is useful for tracking state changes at the account level. Developers debugging contract interactions can identify exactly which accounts were affected by transactions in a specific block. This is also valuable for building state change monitoring tools, forensic analysis, and audit systems that need to track account modifications.


## OpenAPI

````yaml /openapi/arbitrum_node_api/debug_and_trace/debug_getModifiedAccountsByHash.json POST /66f812de2a6724a75a51f60dd6f2a154
openapi: 3.0.0
info:
  title: Chainstack Node API
  version: 1.0.6
  description: >-
    This is an API for interacting with a Chainstack node using the
    debug_getModifiedAccountsByHash method.
servers:
  - url: https://nd-954-882-037.p2pify.com
security: []
paths:
  /66f812de2a6724a75a51f60dd6f2a154:
    post:
      tags:
        - upload
      summary: debug_getModifiedAccountsByHash
      operationId: debugGetModifiedAccountsByHash
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                id:
                  type: integer
                  default: 1
                jsonrpc:
                  type: string
                  default: '2.0'
                method:
                  type: string
                  default: debug_getModifiedAccountsByHash
                params:
                  type: array
                  items:
                    type: string
                  default:
                    - >-
                      0x5765eab677d93b81a1c29de804e115d0e4db8dd40e0deabcf187e4e0d047c758
      responses:
        '200':
          description: Returns a list of accounts modified in the specified block.
          content:
            application/json:
              schema:
                type: object
                properties:
                  jsonrpc:
                    type: string
                  id:
                    type: integer
                  result:
                    type: array
                    items:
                      type: string
                    description: The addresses of the modified accounts.

````