Toy Blockchain in 200 lines of Python
Quick steps to get a peer network running locally for fun and profit.
Pychain depends on Python 3 with asyncio and websockets, install them if required using
pip3 install asyncio
pip3 install websockets
Launch the root node of this peer network
./pychain
This will launch a single node on HTTP port 6001 for API user and will listen on port 8000 for other joining nodes. Since we started this node as a "root node", it will mine our very first block called the "Genesis Block".
Now that we have our root node up and running, lets start one more node. This time around we don't want this node to mine the Genesis Block, so we will tell it about the other node that is already running. Run this on a different terminal.
./pychain -n ws://localhost:8000 -p 6002 -w 8001
Nodes in a peer network communicate with each other via the websocket, so we have to mention the root node's websocket address ws://localhost:8000. This example is running on the same machine so we specify a different HTTP and Websocket ports for this peer.
-h, --help show this help message and exit
-n NODE, --node NODE Add an root peer. If no peers are specified node will
start as root peer
-p HTTP_PORT, --http-port HTTP_PORT
Port on which the HTTP server will run, default port
is 6001
-w WS_PORT, --ws-port WS_PORT
Port on which Websocket will run, default Websocket
port is 8000
-d DIFFICULTY, --difficulty DIFFICULTY
Number of zeros in the hash, default is 4
Learn more about Pychain and Blockchains in general head over to this blog post on devrandom.blog.
This project is released under Apache 2 License - see LICENSE.txt for details.