> ## 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_traceBlockByHash | Robinhood

> Robinhood Chain API method that traces the execution of all transactions in a block identified by its hash. Chainstack Robinhood Chain reference.

Robinhood Chain API method that traces the execution of all transactions in a block identified by its hash. This method provides detailed traces for every transaction and call that took place in the block, including gas usage and performance metrics for each operation.

<Note>
  Learn how to [deploy a node](/docs/debug-and-trace-apis#robinhood) 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` instead.
</Warning>

## Parameters

* `hash` — the hash of the block to be traced.
* `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, creating a map that links each selector and size combination to the number of times it occurred.
  * `callTracer` — tracer that captures information on all call frames executed during a transaction. The resulting nested list of call frames is organized into a tree structure that reflects the way the EVM works and can be used for debugging and analysis purposes.
  * `prestateTracer` — tracer with two modes: `prestate` and `diff`, where the former returns the accounts needed to execute a transaction, and the latter returns the differences between the pre and post-states of the transaction.

## 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_traceBlockByHash` 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 traceBlockByHash = async (blockHash) => {
    const tracer = { tracer: "callTracer" };
    const traces = await provider.send("debug_traceBlockByHash", [blockHash, tracer]);
    console.log(traces);
  };

  traceBlockByHash("0xb3a662bef958318d25b80ba2ce6932d7e2f10262086247fa848f2d96de75fa18");
  ```

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

  block_hash = "0xb3a662bef958318d25b80ba2ce6932d7e2f10262086247fa848f2d96de75fa18"

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

## Use case

The `debug_traceBlockByHash` method is useful for auditing all transactions in a specific block. Developers can use it to analyze gas consumption patterns, identify function call frequencies using the `4byteTracer`, or inspect the full call tree of every transaction in a block using the `callTracer`.

## `debug_traceBlockByHash` code examples

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

  const provider = new JsonRpcProvider("CHAINSTACK_NODE_URL");

  async function call() {
    const result = await provider.send("debug_traceBlockByHash", ["0xf4aab7a559489b816aca197b9a9315b5363a9932c52c3e8bfcf4152588ee096a", {"tracer": "callTracer"}]);
    console.log(result);
  }

  call();
  ```

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

  node_url = "CHAINSTACK_NODE_URL"
  web3 = Web3(Web3.HTTPProvider(node_url))

  result = web3.provider.make_request("debug_traceBlockByHash", ["0xf4aab7a559489b816aca197b9a9315b5363a9932c52c3e8bfcf4152588ee096a", {"tracer": "callTracer"}])
  print(result)
  ```

  ```shell cURL theme={"system"}
  curl -X POST "CHAINSTACK_NODE_URL" \
    -H "Content-Type: application/json" \
    --data '{
      "jsonrpc": "2.0",
      "method": "debug_traceBlockByHash",
      "params": ["0xf4aab7a559489b816aca197b9a9315b5363a9932c52c3e8bfcf4152588ee096a", {"tracer": "callTracer"}],
      "id": 1
    }'
  ```
</CodeGroup>


## OpenAPI

````yaml openapi/robinhood_node_api/debug_and_trace/debug_traceBlockByHash.json POST /
openapi: 3.0.0
info:
  title: Chainstack Node API
  version: 1.0.0
  description: This is an API for interacting with a Chainstack node.
servers:
  - url: >-
      https://robinhood-mainnet.core.chainstack.com/23cf4479b299ab4835d76c05c468ca6e
security: []
paths:
  /:
    post:
      tags:
        - upload
      summary: debug_traceBlockByHash
      operationId: debug_traceBlockByHash
      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_traceBlockByHash
                params:
                  type: array
                  items:
                    anyOf:
                      - type: string
                        title: Block Hash
                        description: The block hash.
                      - type: object
                        title: Tracer type
                        properties:
                          tracer:
                            type: string
                        description: The type of tracer.
                  default:
                    - >-
                      0xf4aab7a559489b816aca197b9a9315b5363a9932c52c3e8bfcf4152588ee096a
                    - tracer: callTracer
      responses:
        '200':
          description: The block traces.
          content:
            application/json:
              schema:
                type: object
                properties:
                  jsonrpc:
                    type: string
                  id:
                    type: integer
                  result:
                    type: object

````