[ANN][TESTNET] Kairos – Bitcoin-style PoW with quantum-fallback addresses

[CreatorofKairos]

https://nimsalcade.github.io/kairos

Kairos

A peer-to-peer electronic cash system built to last

Public testnet is live  ·  Testnet coins have no value  ·  No sale, no premine, no airdrop

What it is
Kairos keeps what has proven itself in Bitcoin (SHA-256d proof-of-work, UTXOs, the chain with the most work wins) and changes what seventeen years of operation have exposed. All of this is active from block 0; none of it is a later soft fork.

• A security budget that never reaches zero. Emission decays smoothly with no halving cliffs, then settles at a permanent 0.6 KRS per block.
  
• A burned base fee. A predictable per-byte fee, adjusted every block (EIP-1559 style). Burning it offsets the tail emission when the chain is busy.
  
• A quantum fallback in every address. Each address commits to a Schnorr key and a hash-based Lamport key. If secp256k1 falls, a soft fork disables elliptic-curve spends and coins move under the hash-based key instead of being stolen or frozen.
  
• The UTXO set is committed in every header (MuHash3072), so nodes can start from a recent snapshot verified against proof-of-work.
  
• Difficulty adjusts every block (ASERT), with 2-minute blocks.
  
• Merge-mining with Bitcoin (Namecoin-style AuxPoW), so a small chain isn't at the mercy of rented SHA-256 hash power.
  
• Malleability-free txids, domain-separated Merkle trees, block height in the header, chain id in every signature (replay protection), optional transaction expiry.

Status: please read

• This is an unaudited public testnet. Testnet KRS have no value and never will.
  
• There is no mainnet, no token sale, no presale and no airdrop. Anyone selling "Kairos" is scamming you.
  
• If a mainnet ever happens, it will be a fair launch with no premine and no presale, and only after the steps in LAUNCH.md: independent audits, a second implementation and at least six months of public testnet.
• The reference implementation is about 4,300 lines of Python (standard library plus optional libsecp256k1), with 78 tests as of 0.4.0. It's built to be read and attacked, not to scale.

Join in three commands (Python 3.9+, macOS or Linux)

Code:

git clone https://github.com/Nimsalcade/kairos.git && cd kairos
python3 -m venv .venv && .venv/bin/pip install coincurve
.venv/bin/python -m kairos --testnet node --mine

Your node finds the network by itself through the built-in seed nodes in Frankfurt, Singapore and Miami. Type help at the prompt.

What I'm asking for

• Run a node and try to break it: consensus bugs, crashes, sync failures, denial of service.
  
• Review the consensus code (params.py, tx.py, block.py, auxpow.py, chain.py) and the whitepaper.
  
• Pool operators: help test merge-mining through createauxblock / submitauxblock.
  
• Honest criticism of the design, especially the tail emission, which I know is contested.
  

Bugs go to GitHub Issues. Security problems go through the private report on the repository's Security tab, not this thread, please.

Links
Code: https://github.com/Nimsalcade/kairos
Whitepaper: https://github.com/Nimsalcade/kairos/blob/main/docs/kairos-whitepaper.pdf
Known limitations: SECURITY.md  ·  Mainnet criteria: LAUNCH.md

Disclosure
The design, whitepaper and reference implementation were drafted with the help of Claude, an AI model made by Anthropic. I deployed and run the testnet. Kairos is independent and not affiliated with or endorsed by Anthropic. Treat every line as unreviewed until people other than me have reviewed it; that's why I'm posting.

I'm Nimsalcade on GitHub. This thread will be linked from the repository README to confirm.

[HashCaliber]

I checked out the GitHub for this project. It's written entirely in Python. Thank you! It's about time we have a Python only coin to follow along with. I'm biased but that's my language of choice. I'll be following this.

[alpha2019]

python crypto for example..... ARO?

[CreatorofKairos]

Update: Kairos 0.4.0 and testnet reset (testnet 2)

0.4.0 is a hard fork, so the testnet has restarted from a new genesis block. Nodes running 0.3.x can no longer connect; please update.

What changed

• Signatures now commit to the amounts and addresses of the coins being spent.
• Soft forks activate by miner signalling (version bits). The quantum-emergency switch is the first deployment, so the network itself can now turn it on.
• Headers-first sync with block download from several peers; a node won't download a chain that carries less work.
• Fast restart from a chainstate snapshot, and optional fast sync from a UTXO snapshot checked against a proof-of-work header commitment.
• Wallet: one-time Lamport keys are recorded before signing; rewards and change go to fresh addresses.
• 78 tests, up from 55, including hostile-peer and snapshot-tampering tests.

Testnet 2
Genesis: 000008fa96a695a8e30751146a123e55ee730693362e0acba2c43ce704b73c51
Seed nodes are unchanged (Frankfurt, Singapore, Miami) and built in.

To update
If you cloned with git:

Code:

cd kairos && git pull
.venv/bin/python -m kairos --testnet node --mine

If you downloaded the ZIP, download it again from GitHub.

Existing wallets and backup codes keep working; balances start at zero on the new chain. Testnet 1 coins are gone, but they never had any value.

Changelog: https://github.com/Nimsalcade/kairos/blob/main/CHANGELOG.md



Note: the whitepaper still describes the 0.3 block header (124 bytes); in 0.4.0 the header is 132 bytes because it also commits to the next block's base fee, and a revised whitepaper will follow.

[CreatorofKairos]

python crypto for example..... ARO?

Not related to ARO. Python is the readable reference; LAUNCH.md says the production node has to be a second implementation, most likely a Bitcoin Core fork.

[CreatorofKairos]

Update: Kairos 0.4.1, and a quantum-switch rehearsal on testnet 2

0.4.1 fixes sending after the post-quantum switch activates: the wallet now signs with Lamport keys automatically. There is no consensus change; it runs on testnet 2 alongside 0.4.0.

Please update before [September 24, 2026], when I will start signalling for the "pq" soft fork. Activation needs 95% of blocks in a 2016-block window, then one more window.

Once active, the change is permanent for testnet 2: only Lamport (hash-based) spends are valid. Transactions become much larger (about 24.6 KB per coin spent), and wallets still on 0.4.0 will not be able to send. That is the point of the rehearsal: to see a real emergency switch-over on a live network.

To update: git pull (or download the 0.4.1 release), then restart your node.

0.4.0 nodes keep working after activation; only sending requires 0.4.1. I will post the activation height as soon as it locks in.

[csriche10]

Discord invite link available?