✨⛓ Simplechain ⛓✨

Interactive blockchain built with Node.js.

Intro

The blockchain is a fascinating technology, but it can also be intimidating. At the time I wrote this code, I had consumed a lot of material regarding the blockchain and cryptocurrencies, but I hadn't satisfied my hunger for knowledge (and still haven't). I wanted to create my own blockchain for some of that knowledge to sink in, and I wanted it to be simple. Simplechain is the result of that, and I hope you find it as helpful as it was for me when I created it.

Usage

First, clone the repo:

$ git clone https://github.com/olistic/simplechain.git
$ cd simplechain

Then, install the dependencies:

$ npm install

And finally, launch the REPL:

$ npm start

Voilà! If you see the SIMPLECHAIN> prompt, it means you're inside the REPL.

Go ahead and try the following commands:

• ADDBLOCK <data>: Mines a block with the provided data and adds it to the chain.
• LISTBLOCKS: Lists all the blocks in the chain.

Advanced Usage

Adjust Difficulty

If you want to tweak the blockchain's difficulty, you can do so via the CLI:

$ npm start -- --difficulty <number>

This number represents the amount of zeros the hashes of the blocks in the blockchain need to begin with. A greater number makes it more difficult (more computationally expensive) to mine a block.

Next Steps

• Implement P2P network of nodes where:
  • Miner nodes broadcast mined blocks
  • User nodes broadcast data to be included in blocks by miners
• Implement peer discovery protocol so nodes can find each other

Resources

• Ever wonder how Bitcoin (and other cryptocurrencies) actually work?