Blockchain POC to CS50 final project

Demo

Here the course Certificate

Blockchain is a decentralized way to save data. In our case, as bitcoin works, the data is financial transactions. First is necessary for the user to create their wallet that's is a pair of RSA256 keys. These will work as address to receive deposits and authenticate withdraws. The API in itself is an abstraction to a Node, it is a piece of the network that decentralize the blockchain, it is responsible for submitting transactions to block and mine them. Mine means doing a proof of work calculation and being responsible for sending the new block to the blockchain. More details in CS50 Readme.

classDiagram
class Wallet {
    public_key
    private_key
    financial_data
    created_at
}

class Transaction {
    sender_public_key
    recipient_public_key
    amount
    description
    sign
    created_at
    do_sign(sender_private_key)
}

class Node {
    transactions
    nodes
    submit_transaction(transaction)
    add_node_address(address)
    sync()
    mine_block()
}

class Block {
    id
    data
    hash
    nonce
    created_at
}

• GET /api/node
  • get current node transactions and other node addresses
• POST /api/node/address
  • add new node address
• DELETE /api/node/transactions
  • clear node transactions
• POST /api/node/mine
  • mine block, aka sync transaction with other nodes, calculate nonce (proof of work), and create a new block to the blockchain
• GET /api/chain
  • get blockchain
• POST /api/chain
  • sync current node with other blockchain and transactions
• POST /api/wallet
  • create new wallet
• POST /api/search/wallet
  • wallet search
• POST /api/transaction
  • submit transaction to node

To run the node locally run make docker-run and then open on browser https://localhost:5000/ to interact with an interface. To run another node to mock transactions and sync between them, use make docker-run APP_NAME=cs50chain-clone PORT=5001 and open https://localhost:5001/ . Also can import the Postman Collection to request directly to the API.

To run tests make docker-test

Jun 14 2022
Name                 Stmts   Miss  Cover
----------------------------------------
app/__init__.py          0      0   100%
app/block.py            85     15    82%
app/config.py            8      0   100%
app/database.py         15      1    93%
app/node.py             79     18    77%
app/transaction.py      55      9    84%
app/wallet.py           58      1    98%
test/__init__.py         0      0   100%
test/test_app.py       107      0   100%
----------------------------------------
TOTAL                  407     44    89%

If you want to persist data, run make docker-migration and it'll create a local sqlite3 database. These commands can be used to run sql queries on the database.

• A Practical Introduction to Blockchain with Python
• On the Origins and Variations of Blockchain Technologies
• Bitcoin Whitepaper
• TypeScript Blockchain
• Code your own blockchain in less than 200 lines of Go!
• Learn Blockchains by Building One
• Best-README-Template

• infra
  • add Dockerfile, make docker-build and use build on make docker-run and make docker-test
• frontend
  • add copy to clipboard button on table lines and copy object
  • clickable link to expand with complete object
• documentation
  • add swagger
  • codeclimate
• online
  • deploy app
  • save blockchain on heroku postgresql

MIT

Made in Brazil