Prototype blockchain written in JavaScript which implements a Proof of Work method, Consensus algorithm and follows best practices for developing decentralized blockchain networks.
The first step in running this project is to run npm install.
In our terminal, we open the project path and run code . to open it in VS Code.
We will start each server ( 5 in total) on localhost:3001, 3002, 3003, 3004, 3005 with the command npm run node_1.
We do the same with each node.
After starting the desired nodes, we can check the blockchain with the /blockchain endpoint.
Example: localhost:3001/blockchain
We can see that each port has a genesis block (the first block in the chain).
We use Postman to register the nodes in the network and create transactions, broadcasting both to the whole network.
In Postman: select POST - > http://localhost:3001/register-and-broadcast-node
To write our parameters we select Body , raw and change text to JSON.
In the parameters we specify the node we want to add:
{
"newNodeUrl" : "http://localhost:3002"
}
If successfull, we will get the { note: 'New node registered with network successfully.' } output in Postman.
We can add any of the 5 nodes we want or all of them.
After registering our nodes in the network, we can mine blocks.
To mine (create) a new block, we use the /mine endpoint on any of the 5 ports. (Ex: localhost:3004/mine)
A new block will be created with index: 2, showing on all ports.
A pending transaction of 6.25 will appear. This is the mining reward given to us for mining a new block.
The amount will be added in our next block mined (index: 3).
We use Postman to add transactions and broadcast them in the network using:
POST -> http://localhost:3001/transaction/broadcast
New transaction example:
{
"amount": 50,
"sender": "JOHN452279HFGADG",
"recipient": "ALEX496498JJGDNGDS"
}
If successful, we will get the { note: 'Transaction created and broadcast successfully.' } output in Postman and our transaction will appear in the chain at pendingTransactions.
Any new transaction will be included in the next newly mined block.
We can access the UI through the /block-explorer endpoint. (Ex: localhost:3001/block-explorer)
This is an index.html file with different functionalities for interacting with the blockchain.