Fair-launch CPU proof of work: 21M cap, 10 minute blocks, no premine, Argon2id mining.
Bitcoin 09 keeps Bitcoin's supply and reward shape but uses Argon2id instead of SHA-256 for proof of work. 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
privacy: https://btc09.org/privacy.html
terms: https://btc09.org/terms.html
Code signing policy / Direct-download status
| 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 |
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.
Download the binary for your system and open it. Running BTC09 without a command starts the local desktop wallet in your browser:
.\btc09-windows-amd64.exeYou can also start it explicitly with btc09 app. New wallets use a 24-word
recovery phrase and an Argon2id-encrypted local file. The app asks for the
password again after restart, can restore the same stable receive address from
the words, shows the balance ready to send, and reviews each payment before
broadcasting it. Activity shows recent sends, received payments, mining
rewards, and confirmation status. Max calculates what can be sent after the
fee. Combine small payments is an optional wallet tool for wallets with many
small outputs; it sends them back to the same wallet and does not increase the
balance or mining rewards. The app runs only on a random 127.0.0.1 port and
does not use a cloud account or external web assets.
Existing V1 wallets remain readable and are never rewritten as recovery
wallets. Their random keys cannot truthfully be covered by a new phrase, so
they keep the existing file-backup flow. Mainnet opens in Fast mode: the app
gets public balance data from https://btc09.org, builds and signs payments on
this computer, and sends only the signed transaction for relay. Passwords,
recovery words, and private keys are never sent. Run btc09 app -mode full to
verify through a local node.
On macOS, download the Apple silicon or Intel ZIP from the release, unzip it,
and open Bitcoin 09.app. If macOS blocks the first launch, verify the ZIP
against SHA256SUMS, then right-click the app and choose Open. Current
community builds are not Apple-notarized; raw Mac binaries are kept only for
command-line users.
Nine Inbox moves notes, links, photos, and files between your own phone and computer. It works without an account and without 09C. Devices pair with a QR code or link, and item contents are encrypted in the browser before upload. The BTC09 wallet links to it as an optional utility; it does not share wallet keys, addresses, balances, or payment activity with the inbox.
Read docs/NINE-INBOX.md for pairing, expiry, recovery, server-visible metadata, limits, and the current background-delivery boundary.
You need Go 1.25.12+. Older Go 1.25 patch releases contain known standard-library security issues and must not be used for release or server builds.
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.
- Download
btc09-windows-amd64.exefrom the latest release. - Open PowerShell in the download folder.
- Run:
.\btc09-windows-amd64.exe node -mineLeave it open. When your computer finds a block, it prints BLOCK FOUND.
Your wallet is created automatically under your user folder.
Wallet stuff:
.\btc09-windows-amd64.exe wallet list
.\btc09-windows-amd64.exe wallet new
.\btc09-windows-amd64.exe send -to ADDRESS -amount 1.5 -seeds seed.btc09.org:9009PowerShell needs the exact file name. btc09 wallet new only works if you
renamed the file to btc09.exe and run .\btc09.exe, or added it to PATH.
-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 desktop wallet or command-line wallet.
Balance notes:
- Fast mode shows the gateway's public chain view without downloading the full chain. The gateway can see queried addresses but cannot spend their funds.
- Full node mode calculates balance from the locally 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-checkto skip that check.
Local sandbox with instant blocks:
./btc09 node -mine -network regtest -datadir /tmp/sandbox
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.
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.
- 88 byte headers, block ids are SHA-256d, PoW check is Argon2id(header) <= target
- legacy difficulty windows through height 12,095; per-block ASERT from height 12,096 with a two-hour half-life
- 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
178.128.52.20:9009
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 reports the active difficulty algorithm, the ASERT activation
height and countdown, target seconds, observed block cadence, and the next
block difficulty once ASERT is active.
Discord:
https://discord.gg/fUuGzwRTzP
Any node can serve its own explorer with -explorer :8009.
There is no official 09C price. Early trading is community OTC only.
Discord has #💱-otc-trading for English WTB/WTS negotiation, and the bot
escrow is live. Start with /trade help or /help; /trade by itself is only
the Discord subcommand menu. Use /trade sell to create a WTS offer.
Use /trade buy to create a WTB offer. Use /trade accept <order_id> to accept
an open offer. The bot holds 09C in escrow at a 1% fee. Only send 09C to the
deposit address the bot
gives you for a specific order. AUD, USD, CNY, USDT, USDC, BTC, ETH, and custom
settlement funds move directly between buyer and seller. The bot never takes
custody of those funds. 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
VPS-generated market-data.json snapshot, so normal page views do not need to
hit the GitHub API.
09C is a native UTXO coin. Exchanges can integrate deposits and withdrawals with the reference node's versioned read-only chain API and strict JSON wallet commands. The exchange integration guide covers release verification, unique deposit addresses, tip-pinned scans, confirmation and reorg handling, withdrawal inspection, broadcast, backups, and a read-only smoke test. BTC09 is not claiming an exchange listing until a venue confirms it. The listing spec records verified outreach status, current commercial requirements, and the no-fake-volume funding policy.
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.
The official Bitcoin 09 software is btc09: reference node, wallet, solo
miner and explorer. Download it only from the project's
GitHub releases and verify the
published checksums.
The official miner supports open-source CPU PPLNS and solo mining. There is no official 09C GPU miner. Do not run miner binaries sent through DMs or file-sharing links. Permissionless third-party software may appear, but the project does not endorse it or ask you to provide a seed phrase, private key, wallet file, remote access, or Discord token.
The official Go client includes non-custodial PPLNS mining. A miner can earn difficulty-weighted shares without running a local full node:
btc09 mine-pool -pool https://btc09.org -address YOUR_09C_ADDRESS -worker rig-1
A synced node can serve v1 solo and v2 PPLNS on one loopback address:
btc09 node -solo-api 127.0.0.1:9010 -pplns-state /secure/path/pplns-window.json
The 0% fee pool pays miners directly in the block coinbase. It has no custody wallet and no withdrawal balance. The client verifies the frozen share window, difficulty weights, direct-payout coinbase, and Merkle commitment before it hashes. The coordinator receives a payout address, never a private key, recovery phrase, or wallet file.
The desktop wallet includes this official CPU miner directly: open Mine,
choose how many CPU threads to use, and press Start mining. The wallet fills
its own public payout address and keeps every private key on the computer. See
PPLNS Mining Protocol v2. Remote solo remains
available with -mode solo and is documented in
Open Mining Protocol v1.
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.
v0.1.34 is a mandatory network update for node and solo-miner operators before height 12,096. That height switches difficulty from the legacy 2,016-block window to per-block ASERT with a two-hour half-life. Wallet files, addresses, transactions, supply, rewards, and proof of work are unchanged. Pool miners receive the current consensus work from the upgraded coordinator.
The wallet-only v0.1.34 beta is available as a signed Android APK and a Linux AppImage from GitHub Releases.
Network:
site: https://btc09.org
seeds: seed.btc09.org:9009, 178.128.52.20:9009, 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 scoring/banning, headers-first sync, DNS seeds, miner/peer stats in the explorer and a friendlier miner UI.
MIT, same as Bitcoin.