A blockchain you can read in ten minutes

ZAK Chain is a complete proof-of-work blockchain in about 150 lines of plain Node.js, with no dependencies. Read it, run it, break it.

See how it works Play ZAK Miner View the code

Fixed supply
Exactly 1,000,000,000 ZAK in the genesis block. Nothing can mint more; miners earn transfer fees instead.

Signed transfers
Ed25519 signatures with per-wallet nonces, so transfers can't be forged or replayed.

Proof of work
SHA-256 blocks chained together, with difficulty retargeting toward one block every 10 seconds.

Peer to peer
Nodes share transfers and blocks and adopt the valid chain with the most total work.

What's in the repo

`zakchain.mjs`	The chain: wallets, signatures, blocks, difficulty, validation, fork choice.
`node.mjs`	An HTTP node that gossips transfers and blocks with its peers.
`wallet.mjs`	Make a wallet, check a balance, send a signed transfer.
`miner.mjs`	A multi-core miner that earns the fees in the blocks it finds.
`explorer/`	A local block explorer: blocks, transfers, addresses, mempool and a difficulty chart.
`test.mjs`	Tests that try to forge, replay, overspend and rewrite history.

Run a node

git clone https://github.com/zeze6544/zakchain && cd zakchain
PORT=7001 node node.mjs
node explorer/server.mjs      # then open http://localhost:7100

You need Node.js 20 or newer. The one-minute guide shows how to connect a second node and mine your first block.

Try it without installing anything

How it works lets you hash, mine and tamper with a tiny chain right in your browser. ZAK Miner is an idle game that does real SHA-256 proof of work in your browser (its game ZAK is not real ZAK).

About

ZakChain is an independent cryptocurrency project under development, bringing together blockchain technology, a website, interactive gaming and supporting software.

The project is focused on building a functional ecosystem, encouraging community participation and exploring opportunities to support charitable causes in the future.

Development is ongoing, with technical features, project documentation and operational arrangements being refined as the ecosystem evolves.

Any future charitable initiatives will be communicated transparently as they are established. Project updates will reflect the actual development status and capabilities of ZakChain.

ZAK has no monetary value and is not for sale.