CENT Blockchain Node API

Technical documentation for the CENT Node Server (app.py). This API allows clients (such as Wallets, Discord Bots, and Block Explorers) to interact with the blockchain network.

1. System Architecture

• Language: Python 3.x
• Framework: Flask (Micro-web framework) handles API requests.
• Concurrency: Multi-threaded. Flask handles HTTP requests on the main thread, while a background thread handles mining and consensus logic.
• Storage: In-memory lists (Python list/dict) with local persistence to blockchain.json.

2. P2P Communication Protocol

The network operates on a decentralized mesh where nodes communicate directly via HTTP.

• Protocol: REST API over HTTP/1.1.
• Discovery: Manual peer registration via IP/Port.
• Sync Mechanism: "Longest Chain Rule." Nodes query peers for their chain length. If a peer has a valid chain longer than the local one, the node replaces its local chain with the peer's chain.

3. API Endpoints

Sending Transactions

Method	Endpoint	Description
POST	/transactions/new	Receives a signed transaction bundle, validates the signature and balance, and adds it to the "Pending" pool.

Payload Example (JSON)

{
  "sender": "CENT26e314df...",    // Sender's Wallet Address
  "recipient": "CENTf382a1...",   // Recipient's Wallet Address
  "amount": 10.5,                 // Amount to send (Float)
  "signature": "30450221...",     // Hex Signature of (sender+recipient+amount+timestamp)
  "timestamp": 1734185400.0,      // Unix timestamp
  "public_key": "04a1b2c3..."     // Sender's raw Public Key Hex
}

Blockchain Data

Method	Endpoint	Description
GET	/chain	Returns the full blockchain data (all blocks and confirmed transactions).
GET	/chain/length	Returns the current height (number of blocks) of the chain.
GET	/transactions/pending	Returns the list of unconfirmed transactions currently in the mempool.

Network & Consensus

Method	Endpoint	Description
POST	/nodes/register	Registers new peer nodes. Required JSON: {"nodes": ["http://IP:PORT"]}.
GET	/nodes/resolve	Triggers manual consensus. The node checks all peers and downloads the longest valid chain.
POST	/block/receive	Used by peers to broadcast a newly mined block to this node.

Wallet & Mining

Method	Endpoint	Description
GET	/mine	(Manual) Forces the node to mine a new block immediately.
GET	/wallet/new	Generates a new SECP256k1 keypair and returns the Address, Private Key, and Public Key.