# eth_getCodeByHash

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

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

Returns the contract bytecode associated with a given code hash (the keccak256 hash of the bytecode). Unlike `eth_getCode`, which looks up code via an account address at a specific block, this method resolves code directly from its hash, letting callers deduplicate bytecode fetches when multiple accounts share the same implementation (e.g., minimal proxies, upgradeable proxies, EIP-7702 delegators). Used by MegaETH's stateless validator to fetch witness-referenced contract code on demand.

Reference: https://www.alchemy.com/docs/chains/megaeth/mega-eth-api-endpoints/eth-get-code-by-hash

## Parameters

| Name | Type | Required | Description |
|------|------|----------|-------------|
| Code hash | string | Yes | The 32-byte keccak256 hash of the contract bytecode (`codeHash` field from an account). |

## Result

**Bytecode** (string): The bytecode associated with the given code hash, as a hexadecimal string. Returns `"0x"` if no code is stored under this hash.

## Example

### Request

```json
{
  "jsonrpc": "2.0",
  "method": "eth_getCodeByHash",
  "params": [
    "0xfa8c9db6c6cab7108dea276f4cd09d575674eb0852c0fa3187e59e98ef977998"
  ],
  "id": 1
}
```

### Response

```json
{
  "jsonrpc": "2.0",
  "result": "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",
  "id": 1
}
```

## Code Examples

### cURL

```bash
curl --request POST \
  --url https://megaeth-mainnet.g.alchemy.com/v2/docs-demo \
  --header 'Content-Type: application/json' \
  --data '{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "eth_getCodeByHash",
  "params": [
    "0xfa8c9db6c6cab7108dea276f4cd09d575674eb0852c0fa3187e59e98ef977998"
  ]
}'
```

### JavaScript

```javascript
const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify({
    jsonrpc: '2.0',
    id: 1,
    method: 'eth_getCodeByHash',
    params: ['0xfa8c9db6c6cab7108dea276f4cd09d575674eb0852c0fa3187e59e98ef977998']
  })
};

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

payload = {
    "jsonrpc": "2.0",
    "id": 1,
    "method": "eth_getCodeByHash",
    "params": ["0xfa8c9db6c6cab7108dea276f4cd09d575674eb0852c0fa3187e59e98ef977998"]
}
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://megaeth-mainnet.g.alchemy.com/v2/docs-demo"

	payload := strings.NewReader("{\n  \"jsonrpc\": \"2.0\",\n  \"id\": 1,\n  \"method\": \"eth_getCodeByHash\",\n  \"params\": [\n    \"0xfa8c9db6c6cab7108dea276f4cd09d575674eb0852c0fa3187e59e98ef977998\"\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://megaeth-mainnet.g.alchemy.com/v2/docs-demo")
  .header("Content-Type", "application/json")
  .body("{\n  \"jsonrpc\": \"2.0\",\n  \"id\": 1,\n  \"method\": \"eth_getCodeByHash\",\n  \"params\": [\n    \"0xfa8c9db6c6cab7108dea276f4cd09d575674eb0852c0fa3187e59e98ef977998\"\n  ]\n}")
  .asString();
```

### C#

```csharp
using RestSharp;


var options = new RestClientOptions("https://megaeth-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\": \"eth_getCodeByHash\",\n  \"params\": [\n    \"0xfa8c9db6c6cab7108dea276f4cd09d575674eb0852c0fa3187e59e98ef977998\"\n  ]\n}", false);
var response = await client.PostAsync(request);

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

```


## OpenRPC Method Specification

```yaml
name: eth_getCodeByHash
description: Returns the contract bytecode associated with a given code hash (the keccak256 hash of the bytecode). Unlike `eth_getCode`, which looks up code via an account address at a specific block, this method resolves code directly from its hash, letting callers deduplicate bytecode fetches when multiple accounts share the same implementation (e.g., minimal proxies, upgradeable proxies, EIP-7702 delegators). Used by MegaETH's stateless validator to fetch witness-referenced contract code on demand.
x-compute-units: 20
params:
  - name: Code hash
    required: true
    description: The 32-byte keccak256 hash of the contract bytecode (`codeHash` field from an account).
    schema:
      title: 32 byte hex value
      type: string
      pattern: ^0x[0-9a-f]{64}$
result:
  name: Bytecode
  description: The bytecode associated with the given code hash, as a hexadecimal string. Returns `"0x"` if no code is stored under this hash.
  schema:
    title: hex encoded bytes
    type: string
    pattern: ^0x[0-9a-f]*$
examples:
  - name: eth_getCodeByHash example
    params:
      - name: Code hash
        value: '0xfa8c9db6c6cab7108dea276f4cd09d575674eb0852c0fa3187e59e98ef977998'
    result:
      name: Bytecode
      value: 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
```