Mini-chain

Run a simple blockchain on your local computer. Special thanks to Hadelin de Ponteves

Tools

• Written and complied using Spyder
• Flask
• Postman
• Remix Ethereum

Blockchain With Cryptocurrency Demo

Connect the blockchain nodes, exchange 'Hadcoins', and mine blocks. For any blocks added, get consensus by calling replace_chain. Get the blockchain and check if it is valid.

1. Run hadcoin_node_[port].py in separate consoles.
2. Using Postman, send requests to http://127.0.0.1:[port]/
3. Send POST connect_node requests to all nodes. Paste nodes.json in request body. Remove receiving node from the post request body. For example, if sending POST connect_node to http://127.0.0.1:5001/ remove http://127.0.0.1:5001/ from the request body.
4. Send GET mine-block to any node.
5. Send POST replace_chain on other nodes.
6. Send POST add_transaction to any node. Paste transaction.json in request body. Replace sender and receiver strings with any name, and amount with any integer.
7. Send GET mine_block to mine the transaction to the blockchain.
8. Send POST replace_chain on other nodes to update the blockchain.

GET methods

• get_chain - gets the full blockchain.
• mine_block - adds a block to the blockchain.
• is_valid - checks if the blockchain is valid.

POST methods

• connect_node - connects a node to the blockchain
• add_transaction - adds a new transaction to the blockchain
• replace_chain - replaces the chain with the longest chain if needed

Ethereum Smart Contract

A smart contract written in Solidity for the Ethereum blockchain. Compile, deploy, and run transactions using Remix Ethereum. Paste hadcoins_ico.sol into main panel.