Building a Local Full-Node Blockchain Explorer from Scratch

As a developer, you’re no newbie to building tools and exploring blockchain technology. However, if you’re using a third-party blockchain explorer like Blockscout, Etherscan, or Infura, there’s usually a limit to the number of requests per second (RPS) you can send before it hits your internet connection’s bandwidth limit. But what if you want more control over your own blockchain? Want to build a local full-node explorer that lets you query the blockchain without using external APIs?

The Case for an Open Source Project

In this article, we’ll look at the benefits of building an open-source blockchain explorer from scratch and show you how to do it in a few simple steps.

Why build your own blockchain explorer?

Building your own blockchain explorer offers a number of benefits:

• More control: Having full control over the codebase means you can be sure that everything is working as expected, without having to use a third party.

• Scalability

  

  : As the number of users grows, a local full node explorer allows for more simultaneous connections, potentially leading to faster performance and higher availability.

• Security: With direct access to blockchain data, you can implement robust security measures like encryption and authentication to protect your users’ data.

Basics: Building a local full node explorer

To build a local full node explorer, we’ll use the Python programming language. We’ll focus on creating a simple and lightweight implementation that uses only the Ethereum blockchain protocol.

import hashlib
import json
class Block:
def __init__(self, hash, index, previous_hash, timestamp, miner):
self.hash = hash
self.index = index
self.previous_hash = previous_hash
self.timestamp = timestamp
self.miner = miner

Step 1: Set up an Ethereum node

First, we need to create a local Ethereum node using Web3.py. We will use the ethers library to connect our blockchain.

from web3 import Web3
w3 = Web3(Web3.HTTPProvider(' 
Replace with your local Ethereum network

Step 2: Create a block

Now that we have our node setup, we can create a new block. We will use the createTransaction method to generate a transaction and add it to the blockchain.

def create_block(data):
return w3.eth.getTransactionCount(w3.currentProvider)

Step 3: Sign the block

Before we send the block to the network, we need to sign it with our account’s private key. To do this, we will use the signTransaction method.

def sign_block(tx_data):
return w3.eth Account.sign_transaction([tx_data], w3.eth.getTransactionCount(w3.currentProvider)).signedTransaction

Step 4: Add the block to the blockchain

Now that we have a signed transaction, let’s add it to the blockchain using the add_block method.

def add_block(block_data):
return w3.eth.sendrawtransaction(block_data)

Putting it all together

Here is a simple example of how you can use these steps to build a local full node explorer:

“`Python

import hashlib

import json

Block class:

def __init__(self, hash, index, previous_hash, timestamp, miner):

self.hash = hash

self.index = index

self.previous_hash = previous_hash

self.timestamp = timestamp

self.miner = miner

def create_block(data):

return w3.eth.getTransactionCount(w3.currentProvider)

def block_characters(tx_data):

return w3.eth.Account.sign_transaction([tx_data], w3.eth.getTransactionCount(w3.currentProvider)).signedTransaction

def add_block(block_data):

return w3.eth.