> ## 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 | Monad

> Monad API method that returns traces for all transactions in a block specified by block number. Available on Monad via Chainstack.

Monad API method that returns traces for all transactions in a block specified by block number. This method is useful for analyzing all transaction executions within a single block.

<Warning>
  **Monad-specific behavior**:

  * The trace options object parameter **must be explicitly provided**. Unlike standard EVM clients where this parameter is optional, Monad RPC will return an error (`-32602 Invalid params`) if the parameter is omitted. Always include the trace options, even if empty (`{}`).
  * When an empty trace options object `{}` is provided, Monad defaults to `callTracer` instead of struct logs, because Monad does not currently support opcode-level struct logs at the VM level.
</Warning>

## Parameters

* `quantity|tag` — the block number as a hexadecimal string, or one of the following block tags:
  * `latest` — the most recent block in the canonical chain
  * `earliest` — the genesis block
  * `pending` — the pending state/transactions
* `object` (optional) — the tracer options:
  * `tracer` — the tracer to use (e.g., `callTracer`, `prestateTracer`)
  * `tracerConfig` — configuration options for the tracer
  * `timeout` — timeout for the trace operation

## Response

* `result` — an array of trace results, one for each transaction in the block. The structure of each trace depends on the tracer used.

## `debug_traceBlockByNumber` code examples

<CodeGroup>
  ```javascript ethers.js theme={"system"}
  const { ethers } = require("ethers");

  const provider = new ethers.JsonRpcProvider("CHAINSTACK_NODE_URL");

  async function traceBlock() {
    const blockNumber = "latest"; // Or use hex like "0x1234"
    const traces = await provider.send("debug_traceBlockByNumber", [
      blockNumber,
      { tracer: "callTracer" }
    ]);
    console.log(`Traced ${traces.length} transactions`);
    traces.forEach((trace, i) => {
      console.log(`Transaction ${i}:`, trace.result?.type || 'unknown');
    });
  }

  traceBlock();
  ```

  ```python web3.py theme={"system"}
  from web3 import Web3

  node_url = "CHAINSTACK_NODE_URL"

  web3 = Web3(Web3.HTTPProvider(node_url))

  traces = web3.provider.make_request('debug_traceBlockByNumber', ['latest', {'tracer': 'callTracer'}])
  print(f'Traced {len(traces["result"])} transactions')
  for i, trace in enumerate(traces['result']):
      print(f'Transaction {i}: {trace.get("result", {}).get("type", "unknown")}')
  ```
</CodeGroup>

## Use case

A practical use case for `debug_traceBlockByNumber` is building block analysis tools that need to understand the complete execution flow of all transactions in a block, such as MEV detection or security monitoring systems.


## OpenAPI

````yaml openapi/monad_node_api/debug_and_trace/debug_traceBlockByNumber.json POST /
openapi: 3.0.0
info:
  title: Monad Node API
  version: 1.0.0
  description: This is an API for interacting with a Monad node.
servers:
  - url: https://monad-testnet.core.chainstack.com/9c5b265f20b3ea5df4f54f70eb74b800
security: []
paths:
  /:
    post:
      tags:
        - Debug and Trace
      summary: debug_traceBlockByNumber
      operationId: debug_traceBlockByNumber
      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
                  default:
                    - latest
                    - tracer: callTracer
      responses:
        '200':
          description: Array of trace results for each transaction.
          content:
            application/json:
              schema:
                type: object
                properties:
                  jsonrpc:
                    type: string
                  id:
                    type: integer
                  result:
                    type: array
                    items:
                      type: object

````