> ## 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_traceBlockByNumber | Arbitrum

Arbitrum API method that traces the execution of all transactions in a block identified by its number. This method provides detailed traces for every transaction and call in the block, including gas usage and internal call information.

<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 [`arbtrace_block`](/reference/arbitrum-arbtrace-block) instead.
</Warning>

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

  [Start for free](https://console.chainstack.com/) and get your app to production levels immediately. No credit card required.

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

## Parameters

* `quantity or tag` — the block number in hex format or block tag:
  * `latest` — the most recent block.
  * `safe` — the block that received justification from the beacon chain.
  * `finalized` — the block accepted as canonical by more than 2/3 of validators.
  * `earliest` — the earliest available or genesis block.
  * `pending` — the pending state and transactions block.

* `tracer` — an object identifying the type of tracer and its configuration:
  * `4byteTracer` — tracer that captures the function signatures and call data sizes for all functions executed during a transaction.
  * `callTracer` — tracer that captures information on all call frames executed during a transaction.
  * `prestateTracer` — tracer with two modes: `prestate` and `diff`, returning account states needed to execute transactions.

## Response types

### `4byteTracer` response

* `object` — the `4byteTracer` traces object:
  * `result` — a map of the function signature, the call data size, and how many times the function was called.

### `callTracer` response

* `object` — the `callTracer` traces object:
  * `from` — the address of the sender who initiated the transaction.
  * `gas` — the units of gas included in the transaction by the sender.
  * `gasUsed` — the total used gas by the call, encoded as hexadecimal.
  * `to` — the address of the recipient of the transaction if it was a transaction to an address. For contract creation transactions, this field is `null`.
  * `input` — the optional input data sent with the transaction.
  * `output` — the return value of the call, encoded as a hexadecimal string.
  * `error` — an error message in case the execution failed.
  * `revertReason` — the reason why the transaction was reverted, returned by the smart contract if any.
  * `calls` — a list of sub-calls made by the contract during the call, each represented as a nested call frame object.

### `prestateTracer` response

* `object` — the `prestateTracer` traces object:
  * `smart contract address` — the address of the smart contract associated with the result.
    * `balance` — the balance of the contract, expressed in Wei and encoded as a hexadecimal string.
    * `code` — the bytecode of the contract, encoded as a hexadecimal string.
    * `nonce` — the nonce of the account associated with the contract, represented as an unsigned integer.
    * `storage` — a map of key-value pairs representing the storage slots of the contract.

## `debug_traceBlockByNumber` 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 traceBlockByNumber = async (block) => {
    const tracer = { tracer: "callTracer" };
    const traces = await provider.send("debug_traceBlockByNumber", [block, tracer]);
    console.log(traces);
  };

  traceBlockByNumber("latest");
  ```

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

  block = "latest"

  tracer = {"tracer": "callTracer"}
  block_traces = web3.provider.make_request('debug_traceBlockByNumber', [block, tracer])
  print(block_traces)
  ```
</CodeGroup>

## Use case

The `debug_traceBlockByNumber` method is useful for analyzing all transactions in a block by number. Developers can use it to calculate average gas usage across transactions, monitor smart contract activity patterns, or build block-level analytics dashboards.


## OpenAPI

````yaml /openapi/arbitrum_node_api/debug_and_trace/debug_traceBlockByNumber.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_traceBlockByNumber method.
servers:
  - url: https://nd-954-882-037.p2pify.com
security: []
paths:
  /66f812de2a6724a75a51f60dd6f2a154:
    post:
      tags:
        - upload
      summary: debug_traceBlockByNumber
      operationId: arbitrumTraceBlockByNumber
      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_traceBlockByNumber
                params:
                  type: array
                  items:
                    anyOf:
                      - type: string
                        title: Block Number
                        description: >-
                          Block number in hex format or tag (latest, earliest,
                          pending, safe, finalized).
                      - type: object
                        title: Tracer type
                        properties:
                          tracer:
                            type: string
                        description: The type of tracer.
                  default:
                    - latest
                    - tracer: callTracer
      responses:
        '200':
          description: The block traces.
          content:
            application/json:
              schema:
                type: object
                properties:
                  jsonrpc:
                    type: string
                  id:
                    type: integer
                  result:
                    type: object

````