> ## 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.

# trace_replayBlockTransactions | Arc

> Arc API method that replays all transactions in a block and returns execution traces for each. Available on Arc via Chainstack.

Arc API method that replays all transactions in a block and returns execution traces for each. This is useful for detailed analysis of block execution with customizable trace options.

## Parameters

* `blockParameter` — the block number (hex) or tag (`latest`, `earliest`, `pending`)
* `traceTypes` — array of trace types to include:
  * `trace` — basic execution trace
  * `vmTrace` — full VM execution trace
  * `stateDiff` — state changes

## Response

* `result` — array of trace results, one per transaction:
  * `output` — return data from the transaction
  * `trace` — array of trace objects (if requested)
  * `vmTrace` — VM execution trace (if requested)
  * `stateDiff` — state differences (if requested)
  * `transactionHash` — hash of the transaction

## `trace_replayBlockTransactions` code examples

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

  const replayBlock = async (blockNumber) => {
      const results = await provider.send("trace_replayBlockTransactions", [
        blockNumber,
        ["trace"]
      ]);

      console.log(`Replayed ${results.length} transactions`);

      for (let i = 0; i < results.length; i++) {
        const result = results[i];
        console.log(`\nTransaction ${i}: ${result.transactionHash}`);
        console.log(`  Output: ${result.output}`);
        console.log(`  Traces: ${result.trace?.length || 0}`);

        if (result.trace && result.trace.length > 0) {
          for (const trace of result.trace) {
            const callType = trace.action.callType || trace.type;
            console.log(`    ${callType}: ${trace.action.from} -> ${trace.action.to || 'Create'}`);
          }
        }
      }
    };

  replayBlock("latest");
  ```

  ```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("trace_replayBlockTransactions", [
      "latest",
      ["trace"]
  ])

  results = result['result']
  print(f"Replayed {len(results)} transactions")

  for i, tx_result in enumerate(results):
      print(f"\nTransaction {i}: {tx_result['transactionHash']}")
      print(f"  Output: {tx_result['output']}")
      traces = tx_result.get('trace', [])
      print(f"  Traces: {len(traces)}")

      for trace in traces:
          call_type = trace['action'].get('callType', trace['type'])
          to = trace['action'].get('to', 'Create')
          print(f"    {call_type}: {trace['action']['from']} -> {to}")
  ```

  ```bash cURL theme={"system"}
  curl -X POST "CHAINSTACK_NODE_URL" \
    -H "Content-Type: application/json" \
    -d '{
      "jsonrpc": "2.0",
      "method": "trace_replayBlockTransactions",
      "params": ["latest", ["trace"]],
      "id": 1
    }'
  ```
</CodeGroup>


## OpenAPI

````yaml openapi/arc_node_api/debug_and_trace/trace_replayBlockTransactions.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://arc-testnet.core.chainstack.com/6caa7fd90475ac9214f7521dd460fa7c
security: []
paths:
  /:
    post:
      tags:
        - upload
      summary: trace_replayBlockTransactions
      operationId: trace_replayBlockTransactions
      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: trace_replayBlockTransactions
                params:
                  type: array
                  default:
                    - '0x3480c62'
                    - - trace
      responses:
        '200':
          description: Returns the result of trace_replayBlockTransactions.
          content:
            application/json:
              schema:
                type: object
                properties:
                  jsonrpc:
                    type: string
                  id:
                    type: integer
                  result:
                    type: array
                    items:
                      type: object
                      properties:
                        output:
                          type: string
                        stateDiff:
                          type: object
                          nullable: true
                        trace:
                          type: array
                          items:
                            type: object
                            properties:
                              type:
                                type: string
                              action:
                                type: object
                                properties:
                                  from:
                                    type: string
                                  callType:
                                    type: string
                                  gas:
                                    type: string
                                  input:
                                    type: string
                                  to:
                                    type: string
                                  value:
                                    type: string
                              error:
                                type: string
                              result:
                                type: object
                                properties:
                                  gasUsed:
                                    type: string
                                  output:
                                    type: string
                              subtraces:
                                type: integer
                              traceAddress:
                                type: array
                                items:
                                  type: object
                        vmTrace:
                          type: object
                          nullable: true
                        transactionHash:
                          type: string
              example:
                jsonrpc: '2.0'
                id: 1
                result:
                  - output: >-
                      0x4e487b710000000000000000000000000000000000000000000000000000000000000012
                    stateDiff: null
                    trace:
                      - type: call
                        action:
                          from: '0x19d7cf8ea0ce468417d1eda365a222a9dcbc7d27'
                          callType: call
                          gas: '0x8d1c0'
                          input: >-
                            0xb61d27f60000000000000000000000001ff9c167b50d05910ffdadb82d3d2da4508330ca0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000006000000000000000000000000000000000000000000000000000000000000000040a617bee00000000000000000000000000000000000000000000000000000000
                          to: '0xd011948bd0d6d433d4ba6df9dc44eb9a2bfa555f'
                          value: '0x0'
                        error: Reverted
                        result:
                          gasUsed: '0x6f50'
                          output: >-
                            0x4e487b710000000000000000000000000000000000000000000000000000000000000012
                        subtraces: 1
                        traceAddress: []
                      - type: call
                        action:
                          from: '0xd011948bd0d6d433d4ba6df9dc44eb9a2bfa555f'
                          callType: delegatecall
                          gas: '0x89bee'
                          input: >-
                            0xb61d27f60000000000000000000000001ff9c167b50d05910ffdadb82d3d2da4508330ca0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000006000000000000000000000000000000000000000000000000000000000000000040a617bee00000000000000000000000000000000000000000000000000000000
                          to: '0xd206ac7fef53d83ed4563e770b28dba90d0d9ec8'
                          value: '0x0'
                        error: Reverted
                        result:
                          gasUsed: '0x5c52'
                          output: >-
                            0x4e487b710000000000000000000000000000000000000000000000000000000000000012
                        subtraces: 2
                        traceAddress:
                          - 0
                      - type: call
                        action:
                          from: '0xd011948bd0d6d433d4ba6df9dc44eb9a2bfa555f'
                          callType: staticcall
                          gas: '0x7530'
                          input: >-
                            0x01ffc9a701ffc9a700000000000000000000000000000000000000000000000000000000
                          to: '0x1ff9c167b50d05910ffdadb82d3d2da4508330ca'
                          value: '0x0'
                        result:
                          gasUsed: '0xf1'
                          output: 0x
                        subtraces: 0
                        traceAddress:
                          - 0
                          - 0
                      - type: call
                        action:
                          from: '0xd011948bd0d6d433d4ba6df9dc44eb9a2bfa555f'
                          callType: call
                          gas: '0x82a56'
                          input: '0x0a617bee'
                          to: '0x1ff9c167b50d05910ffdadb82d3d2da4508330ca'
                          value: '0x0'
                        error: Reverted
                        result:
                          gasUsed: '0xb84'
                          output: >-
                            0x4e487b710000000000000000000000000000000000000000000000000000000000000012
                        subtraces: 0
                        traceAddress:
                          - 0
                          - 1
                    vmTrace: null
                    transactionHash: >-
                      0xfc48f7c70e8ffaa46b1110dc43f32e90f65434a0949edab384d066c820c57ee2

````