bitcoin09

README

Bitcoin 09 (09C)

Fair-launch CPU proof of work: 21M cap, 10 minute blocks, no premine, Argon2id mining.

Bitcoin 09 keeps the Bitcoin shape and changes one thing: proof of work is Argon2id instead of SHA-256. Normal CPUs can mine it, and the 64 MiB memory cost is meant to reduce the easy ASIC/GPU advantage that took over Bitcoin.

site:     https://btc09.org
explorer: https://explorer.btc09.org
discord:  https://discord.gg/fUuGzwRTzP
release:  https://github.com/krutftw/bitcoin09/releases/latest

	Bitcoin	Bitcoin 09
Supply cap	21,000,000	21,000,000
Block reward	50, halves every 210,000 blocks	50, halves every 210,000 blocks
Block time	10 minutes	10 minutes
Premine	none	none
Genesis reward	unspendable	unspendable
Proof of work	SHA-256d (ASICs)	Argon2id 64 MiB (CPU-accessible)
Signatures	ECDSA/Schnorr	Ed25519

Read this first

09C is worth nothing. Bitcoin was worth nothing in 2009 too, that's the whole idea here. No premine, no company, no allocation. The genesis reward is burned to an address nobody can spend from, so every coin that will ever exist gets mined publicly starting at block 1. Mine it because it's fun and you missed 2009. Don't put in money you care about, and don't expect any back.

Quick start

You need Go 1.25+.

git clone https://github.com/krutftw/bitcoin09
cd bitcoin09
go build ./cmd/btc09

Mine with all your cores:

./btc09 node -mine

Your reward address prints at startup (wallet auto-created in ~/.btc09).

For the shortest setup path, read QUICKSTART.md.

Run a node without mining:

./btc09 node

Mining only starts when -mine is present. A non-mining node still syncs, relays blocks/transactions, listens on :9009 by default, and can serve its own explorer with -explorer :8009.

Quick start, Windows release

1. Download btc09-windows-amd64.exe from the latest release.
2. Open PowerShell in the download folder.
3. Run:

.\btc09-windows-amd64.exe node -mine

Leave it open. When your computer finds a block, it prints BLOCK FOUND. Your wallet is created automatically under your user folder.

Wallet stuff:

./btc09 wallet list
./btc09 wallet new
./btc09 send -to ADDRESS -amount 1.5 -seeds seed.btc09.org:9009

-seeds is plural and means peer nodes to broadcast through. It is not a wallet seed phrase option. Do not paste private keys, seed phrases, or wallet file contents into the command line. send spends from the wallet file in your data directory.

09C is a native chain coin, not an Ethereum or Solana token. MetaMask, Phantom, and token-contract wallets do not support it. Use the btc09 wallet for now.

Balance notes:

• The wallet balance is calculated from your local node's synced chain, so a fresh node may show it later than the public explorer while it catches up.
• v0.1.10 and later sync fresh nodes in larger bounded batches and log balance changes as soon as the local chain sees them.
• The running node still prints a regular status line every 30 seconds.
• Coinbase mining rewards are spendable after 100 blocks, same as Bitcoin.
• Mainnet nodes check GitHub for a newer release at startup and only print a notice if one exists. Nothing auto-installs. Use -no-update-check to skip that check.

Local sandbox with instant blocks:

./btc09 node -mine -network regtest -datadir /tmp/sandbox

Why change the proof of work

Bitcoin mining stopped being for normal computers around 2013 when ASICs took over. Today a laptop has a one in millions share against warehouse hardware.

Argon2id needs 64 MiB of memory per hash attempt. Memory bandwidth is the bottleneck, not raw logic speed, so GPUs and ASICs do not get the same clean advantage they get on SHA-256d. Monero's RandomX has used the same broad reasoning for years and CPU mining is still viable there.

Nothing stays ASIC-proof or GPU-proof forever. The aim is simpler: make the gap between normal CPUs and custom hardware smaller than it is on Bitcoin. That's what makes the 2009 experience possible again.

Mining policy

09C is permissionless proof of work. The official node miner is CPU mining, and the current public third-party btc09 miner is listed as CPU-only, but the chain does not try to detect or ban hardware. A valid block is valid work.

If a public GPU, FPGA or heavily optimized miner appears, it should be shared and benchmarked like any other miner. If the community later wants a stronger CPU-biased PoW, that requires a coordinated hard fork, not pool-side rules.

Consensus rules, short version

• 88 byte headers, block ids are SHA-256d, PoW check is Argon2id(header) <= target
• difficulty retargets every 2016 blocks, same as Bitcoin, max 4x move per step
• UTXO model, Ed25519 signatures, base58check addresses (version 0x09)
• coinbase pays subsidy + fees, spendable after 100 blocks
• heaviest total work wins, reorgs replay the UTXO set
• 1 MB max block

Mainnet genesis is pinned by a test: ba685f741a04ddad03d37500ff354ce3887e64dd9cb6154ae236952792e90c3f with the message "the coin that you can mine like it's 2009", nonce 20214.

Default bootstrap seeds are built into the client:

seed.btc09.org:9009
178.128.105.41:9009
103.80.18.140:9009
108.190.240.138:9009

Live block explorer:

https://explorer.btc09.org

Supply/status APIs:

https://explorer.btc09.org/api/status
https://explorer.btc09.org/api/supply
https://explorer.btc09.org/api/circulating_supply

/api/circulating_supply returns the plain circulating supply number. It excludes the burned genesis reward. /api/status also includes the current retarget window: target seconds, observed average block time, blocks to the next retarget, and estimated next difficulty if the window keeps the same average.

Discord:

https://discord.gg/fUuGzwRTzP

Any node can serve its own explorer with -explorer :8009.

Markets

There is no official 09C price. Early trading is community OTC only.

Discord has #💱-otc-trading for quick negotiation and an optional OTC escrow bot for small trades. The bot can hold the seller's 09C, verify the order's deposit address, and release after both sides confirm. Payment in USDT/BTC/fiat still happens directly between buyer and seller, so disputes still need human review.

The public OTC board at https://btc09.org/markets.html lets users draft buy offers, sell offers, and completed-trade references on the website, copy a Discord post, and open a prefilled GitHub issue for the public record. It is not an exchange, it does not set an official price, and there are no price promises.

The hosted board reads the sanitized Discord escrow feed from the BTC09 server. Public offer and completed-trade records are backed by GitHub issues and a static docs/market-data.json snapshot generated by GitHub Actions, so normal page views do not need to hit the GitHub API.

Brand

Logo and brand files are in BRAND.md. Use these instead of random coin art so Bitcoin 09 looks consistent across Discord, pool pages, forum posts and listings.

Third-party pool miners

The official Bitcoin 09 software is btc09: reference node, wallet, solo miner and explorer.

The public pool currently recommends NTMminer for pool mining. NTMminer is a third-party closed-source binary miner that added -a btc09 support in its v1.13.0 release. It only needs a payout address. Do not give any pool miner a seed phrase, private key, wallet file, remote access or Discord token.

NTMminer has NVIDIA GPU support for some other algorithms, but its public btc09 backend is listed as CPU-only. There is no official 09C GPU miner right now. If a third-party GPU miner appears later, that is still permissionless mining. Treat any closed-source pool miner carefully: use only a payout address and never give it wallet secrets.

Tests

go test ./...

Covers the emission schedule and 21M cap, rejection of inflated coinbases, signature checks (wrong key can't spend), double spend rejection, difficulty retargeting, reorgs, and the pinned genesis.

Status

v0.1.18 is current. The node, miner, wallet, P2P sync, built-in seeds, block explorer and supply APIs are live.

Network:

site:     https://btc09.org
seeds:    seed.btc09.org:9009, 178.128.105.41:9009, 103.80.18.140:9009, 108.190.240.138:9009
explorer: https://explorer.btc09.org
release:  https://github.com/krutftw/bitcoin09/releases/latest
discord:  https://discord.gg/fUuGzwRTzP

If you downloaded an early build, upgrade to the latest release. Old clients from before the fork-sync and retarget fixes can get stuck on stale forks.

Stuff I want next, PRs welcome: peer banning and DoS hardening, headers-first sync, DNS seeds, miner/peer stats in the explorer and a friendlier miner UI.

License

MIT, same as Bitcoin.