klay_getcode

How to use it

// yarn add @tatumio/tatum

import { TatumSDK, Klaytn, Network } from '@tatumio/tatum'

const tatum = await TatumSDK.init<Klaytn>({ network: Network.KLAYTN })

const code = await tatum.rpc.getCode('0x898f2afc07924f5a4f9612449e4c4f8eca527515')

await tatum.destroy() // Destroy Tatum SDK - needed for stopping background jobs

Overview

The klay_getCode method is part of the JSON-RPC API, which allows users to interact with the blockchain. This method is specifically used to retrieve the contract code (bytecode) of an account at a specific block number. It is helpful when developers need to examine the bytecode of a deployed contract or validate that the contract code on the blockchain matches the intended code.

Use cases for this method could include:

• Debugging a smart contract
• Verifying the integrity of a deployed contract
• Analyzing contract bytecode for security vulnerabilities

Parameters

The klay_getCode method accepts two parameters:

1. address (string): The address of the contract whose bytecode you want to retrieve. This should be a 20-byte address, formatted as a hex string with a 0x prefix.
   • Example: "0x6eA7d015342b7eb7344F7ebf0150234f41F524d6"
2. block (string): The block number at which you want to retrieve the contract code. This can be specified as a hex string or one of the following special keywords:
   • "earliest": The first block in the blockchain
   • "latest": The most recent block in the blockchain
   • "pending": The upcoming block that is being mined
   • Example: "0x1" or "latest"

Return Object

The klay_getCode method returns a string representing the contract bytecode. The returned value is a hex string with a 0x prefix.

• If the account has contract code, the returned string will contain the bytecode.
• If the account is not a contract or does not exist, the returned string will be 0x.

JSON Examples

Request

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "klay_getCode",
  "params": ["0x6eA7d015342b7eb7344F7ebf0150234f41F524d6", "latest"]
}

Response

{
  "id": 1,
  "jsonrpc": "2.0",
  "result": "0x606060...code_here...3839"
}