# zks_getBytecodeByHash

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

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

Retrieves the bytecode of a transaction by its hash.

Reference: https://www.alchemy.com/docs/chains/zksync/zk-sync-api-endpoints/zks-get-bytecode-by-hash

## Parameters

| Name | Type | Required | Description |
|------|------|----------|-------------|
| Transaction hash | string | Yes | The hash of the transaction. |

## Result

**Bytecode** (integer[]): Array of the transaction's bytecode.

## Example

### Request

```json
{
  "jsonrpc": "2.0",
  "method": "zks_getBytecodeByHash",
  "params": [
    "0x0100067d861e2f5717a12c3e869cfb657793b86bbb0caa05cc1421f16c5217bc"
  ],
  "id": 1
}
```

### Response

```json
{
  "jsonrpc": "2.0",
  "result": [
    0,
    4,
    0,
    255,
    18,
    34
  ],
  "id": 1
}
```

## Code Examples

### cURL

```bash
curl --request POST \
  --url https://zksync-mainnet.g.alchemy.com/v2/docs-demo \
  --header 'Content-Type: application/json' \
  --data '{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "zks_getBytecodeByHash",
  "params": [
    "0x0100067d861e2f5717a12c3e869cfb657793b86bbb0caa05cc1421f16c5217bc"
  ]
}'
```

### JavaScript

```javascript
const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify({
    jsonrpc: '2.0',
    id: 1,
    method: 'zks_getBytecodeByHash',
    params: ['0x0100067d861e2f5717a12c3e869cfb657793b86bbb0caa05cc1421f16c5217bc']
  })
};

fetch('https://zksync-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://zksync-mainnet.g.alchemy.com/v2/docs-demo"

payload = {
    "jsonrpc": "2.0",
    "id": 1,
    "method": "zks_getBytecodeByHash",
    "params": ["0x0100067d861e2f5717a12c3e869cfb657793b86bbb0caa05cc1421f16c5217bc"]
}
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://zksync-mainnet.g.alchemy.com/v2/docs-demo"

	payload := strings.NewReader("{\n  \"jsonrpc\": \"2.0\",\n  \"id\": 1,\n  \"method\": \"zks_getBytecodeByHash\",\n  \"params\": [\n    \"0x0100067d861e2f5717a12c3e869cfb657793b86bbb0caa05cc1421f16c5217bc\"\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://zksync-mainnet.g.alchemy.com/v2/docs-demo")
  .header("Content-Type", "application/json")
  .body("{\n  \"jsonrpc\": \"2.0\",\n  \"id\": 1,\n  \"method\": \"zks_getBytecodeByHash\",\n  \"params\": [\n    \"0x0100067d861e2f5717a12c3e869cfb657793b86bbb0caa05cc1421f16c5217bc\"\n  ]\n}")
  .asString();
```

### C#

```csharp
using RestSharp;


var options = new RestClientOptions("https://zksync-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\": \"zks_getBytecodeByHash\",\n  \"params\": [\n    \"0x0100067d861e2f5717a12c3e869cfb657793b86bbb0caa05cc1421f16c5217bc\"\n  ]\n}", false);
var response = await client.PostAsync(request);

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

```


## OpenRPC Method Specification

```yaml
name: zks_getBytecodeByHash
summary: Retrieves the bytecode of a transaction by its hash.
description: Retrieves the bytecode of a transaction by its hash.
params:
  - name: Transaction hash
    required: true
    description: The hash of the transaction.
    schema:
      title: 32 byte hex value
      type: string
      pattern: ^0x[0-9a-f]{64}$
result:
  name: Bytecode
  description: Array of the transaction's bytecode.
  schema:
    type: array
    title: Bytecode
    description: Array of bytes representing the bytecode.
    items:
      type: integer
      minimum: 0
      maximum: 255
examples:
  - name: zks_getBytecodeByHash example
    params:
      - name: Transaction hash
        value: '0x0100067d861e2f5717a12c3e869cfb657793b86bbb0caa05cc1421f16c5217bc'
    result:
      name: Bytecode
      value:
        - 0
        - 4
        - 0
        - 255
        - 18
        - 34
```