[ANN][CLC2] CoiledCoin II – fair merge-mined SHA-256 | v31.1.1 StallGuard update

[solarsurfer]

CoiledCoin II (CLC2)
A fair, merge-mined SHA-256 relaunch of CoiledCoin (2012)

Launch: Saturday 17 October 2026, 09:00 UTC (10:00 UK)

What is it?
The original CoiledCoin (2012) was merge-mined with Bitcoin and was killed by a 51% attack. Nobody seems to have a copy of its chain any more (I asked on this forum first), so this is an honest relaunch on a brand-new chain with the same spirit: SHA-256, merge-minable with Bitcoin, a small tail emission, and the same AuxPoW chain ID (16). It carries no balances from the old chain.

Thanks to the original CoiledCoin dev team for the idea and the name. The code is Bitcoin Core v31.1 with AuxPoW (merged mining) from Namecoin - thanks to everyone who wrote it.

Coin details

Ticker	CLC2
Algorithm	SHA-256d - merge-mine it with Bitcoin (AuxPoW, chain ID 16) or mine it directly
Block time	2 minutes
Difficulty	LWMA-1 (zawy12), every block over the last 60 blocks; fixed launch difficulty (65,536) for the first 60 blocks
Block reward	20 CLC2, halving every 525,000 blocks (~2 years)
Tail emission	never below 1 CLC2 per block (like the original)
Slow start	reward ramps up over the first 1,440 blocks (~1 day)
Premine	26,000 CLC2 in block 1 (~0.25% of the first two years) - declared and locked, see below
Ports	P2P 8370, RPC 8371
Addresses	start with C (legacy) or clc1 (SegWit)

Premine - declared and locked
I'm being upfront: there is a one-time developer premine of 26,000 CLC2 in block 1 (the developer's share - mine). It is paid to:

Code:

Cdb9tuFPx42wKXmk3CJQEDpikU5kn5FoBQ

This is enforced by the coin's own rules (rule bad-cb-premine in src/validation.cpp): a block 1 that doesn't pay it to this address is invalid, whoever mines it. There is no other premine, no developer fee and no hidden reward. Anyone can watch that address.

Fair launch

• Source code and genesis published ~20 hours before launch, so anyone can check them and build their own node.
• The genesis block is timestamped at the launch time, so no block is valid before launch (apart from the normal 2-hour clock allowance every Bitcoin-based coin has).
• The slow start makes the first blocks worth almost nothing, so starting early gains nothing.

Genesis block

Code:

Message : The i Paper 16/10/2026 Energy bills set for double rise in the new year
Time    : 1792227600 (2026-10-17 09:00:00 UTC)
Nonce   : 802020
Hash    : 0000072d1e172d1ae11bdd13c5be26de45a55f2d70ffc310959d8f50b4222677
Merkle  : 0ca1ff21a2fed4f419c072c9a4ccd12e4f8701bc0ec4157124e594fdddab4ee5

Download / source
GitHub: https://github.com/coiledcoin2/coiledcoin2
Release v31.1-clc2: Windows wallet (coiledcoin2-qt.exe) + node, and Linux (Ubuntu 24.04)

Code:

c3253be29220849e349e60168892f89e2809ab84354a7c3cc134a238c6003c3c  coiledcoin2-31.1-win64.zip
045cabf6f9b3321d486fc16391f5c120aea38bf1c67ebb9559047245a3eb0a8c  coiledcoin2-31.1-x86_64-linux-ubuntu24.04.tar.gz

The Windows programs aren't code-signed, so SmartScreen may warn you ("More info" -> "Run anyway"), or build from source.

Nodes - put this in coiledcoin2.conf if your node can't find peers:

Code:

addnode=clc2seed.shears.co.uk:8370

Mining
Merge-mining pools are very welcome - the more independent hashrate, the safer the chain. Chain ID 16; nodes have createauxblock / submitauxblock and getblocktemplate.

Small miners / Bitaxe: my non-custodial solo pool merge-mines CLC2 alongside Bitcoin (every block pays the miner's own address directly - the pool never holds coins):
https://sha256-mining.shears.co.uk

• CLC2 is free for EVERYONE to merge-mine for the first 30 days (until 16 Nov, 0% fee) - just save a CLC2 address on your dashboard.
• Your Bitaxe keeps solo-mining Bitcoin exactly as before; CLC2 comes on top.

To be clear about my own interest: I run that pool and I hold the premine.

What's next: CLC2 is the first coin of a "new coins" area on the pool. From 16 November, CLC2 can be spent on 30 days' mining of all the new coins we add (more coins coming soon).

Questions, bugs, ideas - reply here or open an issue on GitHub. Thanks for reading!

[solarsurfer]

Note: because the genesis block is timestamped at launch (09:00 UTC), nodes won't run until 2 hours before it. Start your node from 07:00 UTC / 08:00 UK on Saturday. If you started one already and it says "block from the future", delete the blocks and chainstate folders in your CoiledCoin II data folder and start it again after 08:00 UK.Launch-day notes for anyone running their own CLC2 node:

1. Nodes can be started from 08:00 UK / 07:00 UTC today. Before that a node refuses the genesis block (it's dated at launch, 09:00 UTC, and nodes reject blocks more than 2 hours in the future).

2. If you run coiledcoin2d and it stops straight away with "Unable to bind to 127.0.0.1:8371", add this line to your coiledcoin2.conf and start it again:
bind=0.0.0.0
(The default ports clash with a built-in Tor setting. The Windows wallet is not affected unless you have switched its RPC server on. A proper fix will be in the next release.)

3. If your node can't find peers:
addnode=clc2seed.shears.co.uk:8370

Mining starts at 09:00 UTC (10:00 UK).CoiledCoin II is live!

The chain started on time at 09:00 UTC today. Thanks to everyone who ran a node and pointed hashrate at it.

Block 1 - the declared premine, as promised
Block 1 was mined at 09:00:25 UTC and pays exactly the declared 26,000 CLC2 to:

Code:

Cdb9tuFPx42wKXmk3CJQEDpikU5kn5FoBQ

Anyone can check it on their own node:

Code:

coiledcoin2-cli getblock $(coiledcoin2-cli getblockhash 1) 2

There is no other premine and no developer fee.

First hour

• The slow start is working: block rewards began at a fraction of a coin and rise a little every block, reaching the full 20 CLC2 after about a day.
• The first 60 blocks use the fixed launch difficulty (65,536), so blocks come faster than 2 minutes for now. From block 61 the LWMA difficulty adjustment takes over and settles it at 2 minutes.
• Blocks are already being found by several different miners.

Running a node?
If coiledcoin2d stops straight away with "Unable to bind to 127.0.0.1:8371", add this line to coiledcoin2.conf and start it again:

Code:

bind=0.0.0.0

If it can't find peers:

Code:

addnode=clc2seed.shears.co.uk:8370

Mining
More merge-mining pools are very welcome - the more independent hashrate, the safer the chain (AuxPoW chain ID 16).
On my pool CLC2 is free for everyone to merge-mine until 16 November, 0% fee - just save a CLC2 address on your dashboard: sha256-mining.shears.co.uk
(As before: I run that pool and I hold the premine.)

Wallets and source: github.com/coiledcoin2/coiledcoin2

Questions and bug reports welcome here or on GitHub.

[BartMan__X]

CoiledCoin2 (CLC2) Mining Pool
Pool and solo options available at:  
https://miningcrypto.online


Stratum Servers
- USA: us.miningcrypto.online
- Europe: de.miningcrypto.online
- Asia-Pacific: au.miningcrypto.online

Explorer
https://explorer.clc2.miningcrypto.online/

[solarsurfer]

Hi all,
Just an update on CoiledCoin II

So far no problems (I shouldn't have said that!) but everything is going like planned, in fact, better than planned.
In its first two days CLC2 has grown to 18 nodes in 6+ countries, 2 independent pools and a community block explorer. Thanks to everyone running a node!

Block Explorer https://explorer.clc2.miningcrypto.online/

Keep up the good work guys !

Regards

[zomboni]

I hope you guys are fine with me running a community/not official Discord for us to organize ourselves.

https://discord.gg/HnbmgtM3fk

[solarsurfer]

I hope you guys are fine with me running a community/not official Discord for us to organize ourselves.

https://discord.gg/HnbmgtM3fk

Thanks for setting that up, much appreciated! Just a reminder that it's community-run, so official CLC2 news stays in this thread and on https://sha256-mining.shears.co.uk. And nobody will ever ask for your keys or wallet file.

Regards

[solarsurfer]

Welcome to the new CLC2 miner!

Since yesterday afternoon someone has been merge-mining CoiledCoin II at around 4–5 PH/s (rewards to CfXJrCuCEzdnTV9AeRyf872hP1FfgjkKNS). Great to see, and it makes the chain much stronger.

One request: your CLC2 blocks are currently empty (coinbase only), so ordinary transactions are only being confirmed when the smaller pools find a block. If you could make sure your CLC2 node includes mempool transactions in its blocks, that would help everyone using CLC2.

Thanks, and happy mining!

Important Update

CoiledCoin II Core 31.1.1 – "ASERT with Shears StallGuard" (upgrade required)

On 30–31 October a very large merge-miner (~4.7 PH/s, about 300x the usual network) mined CLC2 for a few hours and then left. The old difficulty rule (LWMA) had climbed to ~126 million and only comes down slowly, so the chain stopped at block 9,924. Without a change it would have taken weeks to recover.

From block 9,925, CLC2 uses "ASERT with Shears StallGuard":

• Step-by-step ASERT (aserti3-2d maths from Bitcoin Cash – credit to Mark Lundeberg & Jonathan Toomim), 30-minute half-life: difficulty follows every block, up and down.
• Shears StallGuard: if no block is found for 3 hours, the next block gets easier – halving every further 30 minutes. A big miner leaving can no longer freeze the chain.
• A floor of 1,000,000 – about one block an hour for a single 1.2 TH/s Bitaxe. It never becomes "free" to mine, however long it is idle.
• Block times may be at most 10 minutes in the future, so timestamps can't be pushed ahead to game it.

Block 9,925 restarts at difficulty 1,000,000. Nothing before 9,924 changes – no coins or balances are affected.

Everyone running CLC2 needs 31.1.1 – nodes, pools, wallets. Older versions stay stuck at 9,924; when you upgrade, your node simply catches up.

Source: https://github.com/coiledcoin2/coiledcoin2 (tag v31.1.1)
Wallets for Windows, Linux and Raspberry Pi: https://github.com/coiledcoin2/coiledcoin2/releases/tag/v31.1.1
Explorer: https://clc2-explorer.shears.co.uk

Node operators: if your rpcport is P2P port + 1 (the default 8370/8371), add listenonion=0 and bind=0.0.0.0 to coiledcoin2.conf, or the node won't start.

Merge-mining pools: please make sure your CLC2 node includes mempool transactions in its blocks – it helps everyone using CLC2.

Thanks to everyone mining CoiledCoin II.
Andy – Shears Mining