> For the complete documentation index, see [llms.txt](https://docs.getblock.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.getblock.io/api-reference/optimism-op/optimism_eth_getcode.md).

# eth\_getCode - Optimism

Example code for the eth\_getCode json-rpc method. Сomplete guide on how to use eth\_getCode json-rpc in GetBlock.io Web3 documentation.

This method retrieves the EVM bytecode stored at a specific address. If the address is an externally owned account (EOA) or an empty address, it returns `'0x'`. This is useful for verifying contract deployments, analyzing contracts, and checking whether an address is a contract or an EOA. The bytecode is the compiled version of the smart contract's source code.

### Parameters

| Parameter | Type           | Description                                                    | Required |
| --------- | -------------- | -------------------------------------------------------------- | -------- |
| address   | DATA, 20 Bytes | The address to retrieve bytecode from.                         | Yes      |
| block     | QUANTITY\|TAG  | Block number in hex, or `'latest'`, `'earliest'`, `'pending'`. | Yes      |

### Request

{% tabs %}
{% tab title="cURL" %}

```bash
curl --location 'https://shared.us-east-1.getblock.io/<ACCESS_TOKEN>' \
--header 'Content-Type: application/json' \
--data '{
   "jsonrpc": "2.0",
   "method": "eth_getCode",
    "params": [
        "0x4200000000000000000000000000000000000006",
        "latest"
    ],
    "id": "getblock.io"
}'
```

{% endtab %}

{% tab title="Axios" %}

```javascript
import axios from 'axios'
let data = JSON.stringify({
    "jsonrpc": "2.0",
   "method": "eth_getCode",
    "params": [
        "0x4200000000000000000000000000000000000006",
        "latest"
    ],
    "id": "getblock.io"
};

let config = {
  method: "post",
  maxBodyLength: Infinity,
  url: "https://shared.us-east-1.getblock.io/<ACCESS_TOKEN>",
  headers: {
    "Content-Type": "application/json",
  },
  data: data,
};

axios
  .request(config)
  .then((response) => {
    console.log(JSON.stringify(response.data));
  })
  .catch((error) => {
    console.log(error);
  });

```

{% endtab %}

{% tab title="Request" %}

```python
import requests
import json

url = "https://shared.us-east-1.getblock.io/<ACESS_TOKEN>"

payload = json.dumps({
   "jsonrpc": "2.0",
    "method": "eth_getCode",
    "params": [
        "0x4200000000000000000000000000000000000006",
        "latest"
    ],
    "id": "getblock.io"
})
headers = {
  'Content-Type': 'application/json'
}

response = requests.request("POST", url, headers=headers, data=payload)

print(response.text)

```

{% endtab %}

{% tab title="Rust" %}
{% code overflow="wrap" %}

```rs
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let client = reqwest::Client::builder()
        .build()?;

    let mut headers = reqwest::header::HeaderMap::new();
    headers.insert("Content-Type", "application/json".parse()?);

    let data = r#"{
   "jsonrpc": "2.0",
   "method": "eth_getCode",
    "params": [
        "0x4200000000000000000000000000000000000006",
        "latest"
    ],
    "id": "getblock.io"
}"#;

    let json: serde_json::Value = serde_json::from_str(&data)?;

    let request = client.request(reqwest::Method::POST, "https://shared.us-east-1.getblock.io/<ACCESS_TOKEN>")
        .headers(headers)
        .json(&json);

    let response = request.send().await?;
    let body = response.text().await?;

    println!("{}", body);

    Ok(())
}
```

{% endcode %}
{% endtab %}
{% endtabs %}

### Response

A successful response returns the following:

{% code overflow="wrap" %}

```json
{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": "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"
}
```

{% endcode %}

### Response Parameters

* **`id`**: A unique request identifier, matching the `id` sent in the request body.
* **`jsonrpc`**: Specifies the use of JSON-RPC version 2.0.
* **`result`**: The bytecode at the address as a hexadecimal string. Returns `'0x'` for EOAs or empty addresses.

### Use Case

The eth\_getCode method is commonly used for:

* **Contract verification**
* **EOA vs contract detection**
* **Security analysis**
* **Bytecode comparison**

#### Error handling

| Status Code | Error Message    | Cause                                                                                                                                |
| ----------- | ---------------- | ------------------------------------------------------------------------------------------------------------------------------------ |
| 404         | Not Found        | Missing or invalid ACCESS\_TOKEN.                                                                                                    |
| -32602      | Invalid argument | <ul><li>The Address not 20 bytes or missing prefix</li><li>block hash isn't accurate or incomplete</li><li>keyword missing</li></ul> |

#### Integration with Web3

The `eth_getCode` method helps developers to:

* Detect whether a user is interacting with a contract or a wallet
* Validate deployed bytecode for audit and debugging purposes
* Build tools that identify proxies, multicall contracts, routers, and libraries
* Support trustless dapps that rely on on-chain introspection
* Ensure safe interactions by verifying contract code before sending transactions

{% tabs %}
{% tab title="Ethers.js" %}

```javascript
import { ethers } from "ethers";
const RPC_URL = "https://shared.us-east-1.getblock.io/<ACCESS_TOKEN>";
const provider = new ethers.JsonRpcProvider(RPC_URL);
async function Call() {
  try {
     const result = await provider.send("eth_getCode",
  [
        "0x4200000000000000000000000000000000000006",
        "latest"
    ],);    
console.log("The result:", result);
    return result;
  } catch (error) {
    console.error("The error:", error);
    throw error;
  }
}
```

{% endtab %}

{% tab title="Viem" %}

```jsx
import { createPublicClient, http } from 'viem';
import { optimism } from 'viem/chains';

// Create Viem client with GetBlock
const client = createPublicClient({
  chain: optimism,
  transport: http('https://shared.us-east-1.getblock.io/<ACCESS_TOKEN>'),
});

// Using the method through Viem
async function Call() {
    try {
        // Method-specific Viem implementation
        const result = await client.request({
          "method": "eth_getCode",
    "params": [
        "0x4200000000000000000000000000000000000006",
        "latest"
    ]
        });
        console.log('Result:', result);
        return result;
    } catch (error) {
        console.error('Viem Error:', error);
        throw error;
    }
}

```

{% endtab %}
{% endtabs %}