pyncoin

This project is a python port of Naivecoin, an excellent tutorial that lets you implement a fully functioning blockchain and cryptocurrency in TypeScript for educational purposes.

Description

In this repo you find the implementation of a full node for the pyncoin blockchain. Only the features strictly necessary to make the node work are implemented.

As a user interface the node starts a simple web server that provides the following REST services:

• GET /blocks: Returns the blockchain known to this node
• POST /mineBlock: Mines a new block. Include the data you wish to put in the block as a string in the data parameter.
• GET /peers: Returns the list of the peers known to this node
• POST /addPeer: Adds a new peer to the node. The node does not discover other nodes, you should add them manually calling this service and passing the address of the peer node in ws://127.0.0.1:6000 format in the peer parameter.

The blockchain is not persisted by the node, it is kept only in the memory.

pyncoin also manages a WebSocket interface to communcicate with peer nodes.

Getting Started

Dependencies

pyncoin depends on the following python libraries:

• twisted
• autobahn
• flask
• bitstring

pyncoin is developed and tested on python 3.

Installing

Install the dependent libraries above and check out the contents of this repository into a separate folder.

Executing program

Start the node by passing the port number of the web server and the p2p server to main.py:

python main.py 5000 6000

This command starts a web server at 127.0.0.1:5000 and a p2p node at 127.0.0.1:6000. You can communicate with the web server with the simple API described in the introduction of the readme, for example:

curl -d "data=Hello+World%21" -X POST http://127.0.0.1:5000/mineBlock
curl http://127.0.0.1:5000/blocks

If you want, you can also start a second node on the same machine with different ports:

python main.py 5001 6001

And connect the two nodes:

curl -d "peer=ws%3A%2F%2F127.0.0.1%3A6000" -X POST http://127.0.0.1:5000/addPeer
curl http://127.0.0.1:5000/peers

Authors

@jtolgyesi

License

This project is licensed under the MIT License - see the LICENSE file for details

Acknowledgments

Many thanks to Lauri Hartikka for his original tutorial of Naivecoin.