# arbtrace_replayTransaction

> For the complete documentation index, see [llms.txt](/docs/llms.txt).

POST https://arb-mainnet.g.alchemy.com/v2/{apiKey}

Replays a specific transaction and returns the requested trace types without actually executing it on the network. This is an Arbitrum-specific tracing method that works for pre-Nitro blocks (before block 22,207,815). For post-Nitro blocks, use Geth debug_* methods.


Reference: https://www.alchemy.com/docs/chains/arbitrum/arbitrum-api-endpoints/arbtrace-replay-transaction

## Parameters

| Name | Type | Required | Description |
|------|------|----------|-------------|
| Transaction hash | string | Yes | The hash of the transaction to replay. |
| Trace types | enum[] | Yes | Array of trace types to return. Valid values: "trace", "vmTrace", "stateDiff".  |

## Result

**Trace result** (object): The trace result object for the replayed transaction.

## Example

### Request

```json
{
  "jsonrpc": "2.0",
  "method": "arbtrace_replayTransaction",
  "params": [
    "0xd2ea43b18e2f0acb66b36e773f20a4e9a1ee2df00a9794f63c2f4d0519cbe12a",
    [
      "trace"
    ]
  ],
  "id": 1
}
```

### Response

```json
{
  "jsonrpc": "2.0",
  "result": {
    "output": "0x",
    "stateDiff": null,
    "trace": [
      {
        "action": {
          "callType": "call",
          "from": "0x00000000000000000000000000000000000a4b05",
          "gas": "0x0",
          "input": "0x",
          "to": "0xa4b05fffffffffffffffffffffffffffffffffff",
          "value": "0x0"
        },
        "result": {
          "gasUsed": "0x0",
          "output": "0x"
        },
        "subtraces": 0,
        "traceAddress": [],
        "type": "call"
      }
    ],
    "vmTrace": null
  },
  "id": 1
}
```

## Code Examples

### cURL

```bash
curl --request POST \
  --url https://arb-mainnet.g.alchemy.com/v2/docs-demo \
  --header 'Content-Type: application/json' \
  --data '{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "arbtrace_replayTransaction",
  "params": [
    "0xd2ea43b18e2f0acb66b36e773f20a4e9a1ee2df00a9794f63c2f4d0519cbe12a",
    [
      "trace"
    ]
  ]
}'
```

### JavaScript

```javascript
const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify({
    jsonrpc: '2.0',
    id: 1,
    method: 'arbtrace_replayTransaction',
    params: [
      '0xd2ea43b18e2f0acb66b36e773f20a4e9a1ee2df00a9794f63c2f4d0519cbe12a',
      ['trace']
    ]
  })
};

fetch('https://arb-mainnet.g.alchemy.com/v2/docs-demo', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));
```

### Python

```python
import requests

url = "https://arb-mainnet.g.alchemy.com/v2/docs-demo"

payload = {
    "jsonrpc": "2.0",
    "id": 1,
    "method": "arbtrace_replayTransaction",
    "params": ["0xd2ea43b18e2f0acb66b36e773f20a4e9a1ee2df00a9794f63c2f4d0519cbe12a", ["trace"]]
}
headers = {"Content-Type": "application/json"}

response = requests.post(url, json=payload, headers=headers)

print(response.text)
```

### Go

```go
package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://arb-mainnet.g.alchemy.com/v2/docs-demo"

	payload := strings.NewReader("{\n  \"jsonrpc\": \"2.0\",\n  \"id\": 1,\n  \"method\": \"arbtrace_replayTransaction\",\n  \"params\": [\n    \"0xd2ea43b18e2f0acb66b36e773f20a4e9a1ee2df00a9794f63c2f4d0519cbe12a\",\n    [\n      \"trace\"\n    ]\n  ]\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}
```

### Java

```java
HttpResponse<String> response = Unirest.post("https://arb-mainnet.g.alchemy.com/v2/docs-demo")
  .header("Content-Type", "application/json")
  .body("{\n  \"jsonrpc\": \"2.0\",\n  \"id\": 1,\n  \"method\": \"arbtrace_replayTransaction\",\n  \"params\": [\n    \"0xd2ea43b18e2f0acb66b36e773f20a4e9a1ee2df00a9794f63c2f4d0519cbe12a\",\n    [\n      \"trace\"\n    ]\n  ]\n}")
  .asString();
```

### C#

```csharp
using RestSharp;


var options = new RestClientOptions("https://arb-mainnet.g.alchemy.com/v2/docs-demo");
var client = new RestClient(options);
var request = new RestRequest("");
request.AddJsonBody("{\n  \"jsonrpc\": \"2.0\",\n  \"id\": 1,\n  \"method\": \"arbtrace_replayTransaction\",\n  \"params\": [\n    \"0xd2ea43b18e2f0acb66b36e773f20a4e9a1ee2df00a9794f63c2f4d0519cbe12a\",\n    [\n      \"trace\"\n    ]\n  ]\n}", false);
var response = await client.PostAsync(request);

Console.WriteLine("{0}", response.Content);

```


## OpenRPC Method Specification

```yaml
name: arbtrace_replayTransaction
summary: Replays a transaction returning the requested traces.
description: |
  Replays a specific transaction and returns the requested trace types without actually executing it on the network. This is an Arbitrum-specific tracing method that works for pre-Nitro blocks (before block 22,207,815). For post-Nitro blocks, use Geth debug_* methods.
x-compute-units: 80
params:
  - name: Transaction hash
    required: true
    description: The hash of the transaction to replay.
    schema:
      title: 32 byte hex value
      type: string
      pattern: ^0x[0-9a-f]{64}$
  - name: Trace types
    required: true
    description: |
      Array of trace types to return. Valid values: "trace", "vmTrace", "stateDiff".
    schema:
      title: Trace types
      type: array
      description: Array of trace types to return (e.g., ["trace"]).
      items:
        type: string
        enum:
          - trace
          - vmTrace
          - stateDiff
result:
  name: Trace result
  description: The trace result object for the replayed transaction.
  schema:
    title: Trace call result
    type: object
    properties:
      output:
        title: Output
        type: string
        description: The return value of the call, encoded as hexadecimal.
      stateDiff:
        title: State diff
        description: The state differences, if requested. Null if not requested.
        nullable: true
      trace:
        title: Trace array
        type: array
        description: Array of trace objects for the call.
        items:
          type: object
          properties:
            action:
              title: Trace action
              type: object
              properties:
                callType:
                  title: Call type
                  type: string
                  description: The type of call (e.g., "call", "delegatecall", "staticcall").
                from:
                  title: From address
                  type: string
                  pattern: ^0x[0-9a-fA-F]{40}$
                  description: The address of the sender.
                gas:
                  title: Gas
                  type: string
                  pattern: ^0x([1-9a-f]+[0-9a-f]*|0)$
                  description: The gas provided for the call, encoded as hexadecimal.
                input:
                  title: Input data
                  type: string
                  description: The input data sent with the call.
                to:
                  title: To address
                  description: The address of the receiver. Null for contract creation.
                  oneOf:
                    - title: hex encoded address
                      type: string
                      pattern: ^0x[0-9a-fA-F]{40}$
                    - type: 'null'
                value:
                  title: Value
                  type: string
                  pattern: ^0x([1-9a-f]+[0-9a-f]*|0)$
                  description: The value transferred in wei, encoded as hexadecimal.
            error:
              title: Error
              type: string
              nullable: true
            result:
              title: Trace result
              type: object
              properties:
                gasUsed:
                  title: Gas used
                  type: string
                  pattern: ^0x([1-9a-f]+[0-9a-f]*|0)$
                  description: The amount of gas used by the trace, encoded as hexadecimal.
                output:
                  title: Output
                  type: string
                  description: The return data from the call, encoded as hexadecimal.
            subtraces:
              type: integer
            traceAddress:
              type: array
              items:
                type: integer
            type:
              type: string
      vmTrace:
        title: VM trace
        description: The VM trace, if requested. Null if not requested.
        nullable: true
examples:
  - name: arbtrace_replayTransaction example
    params:
      - name: Transaction hash
        value: '0xd2ea43b18e2f0acb66b36e773f20a4e9a1ee2df00a9794f63c2f4d0519cbe12a'
      - name: Trace types
        value:
          - trace
    result:
      name: Trace result
      value:
        output: 0x
        stateDiff: null
        trace:
          - action:
              callType: call
              from: '0x00000000000000000000000000000000000a4b05'
              gas: '0x0'
              input: 0x
              to: '0xa4b05fffffffffffffffffffffffffffffffffff'
              value: '0x0'
            result:
              gasUsed: '0x0'
              output: 0x
            subtraces: 0
            traceAddress: []
            type: call
        vmTrace: null
```