zks_getBytecodeByHash - zkSync

Example code for the zks_getBytecodeByHash JSON-RPC method. Сomplete guide on how to use zks_getBytecodeByHash JSON-RPC in GetBlock.io Web3 documentation.

Returns the bytecode of a contract by its bytecode hash. zkSync stores deployed bytecode indexed by hash — multiple deployed contracts may share the same bytecode.

Parameters

Parameter	Type	Required	Description
bytecodeHash	string	Yes	Bytecode hash (32 bytes)

Request Example

cURL

curl --location --request POST 'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "zks_getBytecodeByHash",
    "params": [
        "0x0100067d861e2f5717a12c3e869cfb657793b86bbb0caa05cc1421f16c5217bc"
    ],
    "id": "getblock.io"
}'

JavaScript (Axios)

import axios from 'axios';

const data = JSON.stringify({
    "jsonrpc": "2.0",
    "method": "zks_getBytecodeByHash",
    "params": [
        "0x0100067d861e2f5717a12c3e869cfb657793b86bbb0caa05cc1421f16c5217bc"
    ],
    "id": "getblock.io"
});

const config = {
    method: 'post',
    url: 'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/',
    headers: {
        'Content-Type': 'application/json'
    },
    data: data
};

axios(config)
    .then(response => console.log(JSON.stringify(response.data, null, 2)))
    .catch(error => console.log(error));

Python (Requests)

import requests
import json

url = "https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/"

payload = json.dumps({
    "jsonrpc": "2.0",
    "method": "zks_getBytecodeByHash",
    "params": [
        "0x0100067d861e2f5717a12c3e869cfb657793b86bbb0caa05cc1421f16c5217bc"
    ],
    "id": "getblock.io"
})

headers = {
    'Content-Type': 'application/json'
}

response = requests.post(url, headers=headers, data=payload)
print(response.text)

Rust (Reqwest)

use reqwest::Client;
use serde_json::json;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let client = Client::new();

    let payload = json!({
        "jsonrpc": "2.0",
        "method": "zks_getBytecodeByHash",
        "params": [
                "0x0100067d861e2f5717a12c3e869cfb657793b86bbb0caa05cc1421f16c5217bc"
        ],
        "id": "getblock.io"
});

    let response = client
        .post("https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/")
        .header("Content-Type", "application/json")
        .json(&payload)
        .send()
        .await?;

    let result: serde_json::Value = response.json().await?;
    println!("{:#?}", result);

    Ok(())
}

Response Example

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": [
        0,
        4,
        0,
        0,
        4
    ]
}

Response Parameters

Field	Type	Description
result	array of integer	Array of uint8 values — the contract's EraVM bytecode bytes

Use Cases

• Contract verification flows

• Inspecting bytecode shared by multiple deployments

• Off-chain EraVM bytecode analysis

Error Handling

Status Code	Error Message	Cause
403	Forbidden	Missing or invalid <ACCESS-TOKEN>
429	Too Many Requests	Rate limit exceeded for your plan

SDK Integration

zksync-ethers (JavaScript)

import { Provider } from 'zksync-ethers';

const provider = new Provider('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/');

// zksync-ethers exposes both standard Ethereum methods and zks_* methods
// through typed accessors. For raw access:
const result = await provider.send('zks_getBytecodeByHash', ["0x0100067d861e2f5717a12c3e869cfb657793b86bbb0caa05cc1421f16c5217bc"]);
console.log(result);

zksync2-python (Python)

from zksync2.module.module_builder import ZkSyncBuilder

zk_web3 = ZkSyncBuilder.build('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/')

# zksync2-python exposes the JSON-RPC layer directly.
result = zk_web3.zksync._zks_endpoints if 'zks_getBytecodeByHash'.startswith('zks_') else None
# Or call any method generically:
result = zk_web3.provider.make_request('zks_getBytecodeByHash', ["0x0100067d861e2f5717a12c3e869cfb657793b86bbb0caa05cc1421f16c5217bc"])
print(result)