Architecture
One chain. Hard money. Post-quantum from block 1.
xCoin (ticker XID) is a Bitcoin-style UTXO chain rebuilt around two decisions: every spend is signed with a post-quantum signature, and every block is mined with a memory-hard proof-of-work that runs on the machine you already own. Mainnet has been live since genesis was mined on September 26, 2026, 00:00 UTC; explorer at superknet.com. Testnet A, the rehearsal chain, is retired.
Consensus
MetalDAG proof-of-work. Ethash-family: Keccak-f1600 over a large pseudo-random dataset, so a hash is bounded by memory bandwidth rather than arithmetic. The dataset is 4 GiB at launch and grows 128 MiB per epoch; an epoch is 14 days of time counted from genesis, not a block count. Nodes verify with a small light cache (dataset ÷ 128, 32 MiB at epoch 0) and never build the full dataset. Unified memory on Apple Silicon is the natural fit, which is the point: a Mac on a desk is competitive. The code calls MetalDAG memory-hard and Apple-Silicon-favoring and claims nothing more.
5-minute block target, ASERT difficulty. Difficulty retargets every block with anchored ASERT (two-hour half-life), so hashrate arriving or leaving is absorbed within hours instead of a two-week window, with no emergency cliffs. Each 110,000-block step works out to about 382 days at the target rate; the reward reaches its 1.5 XID floor around 2063, and the last coin is mined around 2363.
The Annual Tenth. Blocks 1–20,000 pay 6.25 XID, 20,001–40,000 pay 12.5, 40,001–60,000 pay 25, and 60,001–220,000 pay 50 (to about December 2028). From block 220,001 the reward is 10% less every 110,000 blocks (about 382 days): 45, 40.50, 36.45 … never below 1.5 XID (about 2063 to 2325), then it fades 10% a step to a 0.1 XID tail; the last coin is mined around 2363, exactly 100,000,000 XID. 25% of the cap is mined by about 2032, 50% by 2046, 75% by 2177, 99% by 2330. Full schedule.
Every rule, every node. Full nodes validate proof-of-work, signatures, and money supply independently. There is no checkpoint authority, no privileged key, no admin path.
Spend authority
Every output on xCoin is a witness v3 program: a 32-byte commitment to a Merkle root of algorithm-tagged leaves, ML-DSA-65 (FIPS 204, NIST's standardized lattice signature) for everyday spends and SLH-DSA-SHA2-128s (FIPS 205, hash-based) as the fallback. Spending requires a real post-quantum signature in the witness; there is no key path.
There is no classical path and no hybrid path for spends. No ECDSA, no Schnorr, no "legacy" outputs waiting to be drained the day a large quantum computer arrives. The spend-path question that every retrofitted chain still has to answer was answered at genesis: there is only post-quantum.
Addresses are bech32m witness v3: xpa1r…. The program is the Merkle root of the spend tree, and the ML-DSA leaf script holds only SHA-256 of the public key; the 1,952-byte key itself rides on the witness when the output is spent. A post-quantum signature check costs 2 sigops; an ML-DSA-65 signature is 3,309 bytes and a one-input spend weighs about 5,650 WU, which the 64,000,000 WU block weight ceiling accounts for.
Monetary policy
| Parameter | Value | Note |
|---|---|---|
| Maximum supply | 100,000,000 XID | MAX_MONEY in consensus; no mechanism can exceed it. |
| Block subsidy | 50 XID after the warm-up | A warm-up of 6.25, 12.5 and 25 XID for 20,000 blocks each, then 50 XID per block to block 220,000, then 10% less every 110,000 blocks (about 382 days), never below a 1.5 XID floor (about 2063 to 2325), then a fade of 10% a step to a 0.1 XID tail and the last coin around 2363, exactly 100,000,000 XID. No premine, no founder allocation; 8 decimals. |
| Mined supply | 100,000,000 XID | The whole cap: the schedule sums to it exactly, to the sat. |
| Founder allocation | None | No premine, no founder allocation, no token sale. Supply begins at zero; block 1 is an ordinary block paying the block subsidy plus fees to whoever mines it. |
| Genesis | Mined | Block 0 mints nothing; its coinbase carries the charter commitment. Mined September 26, 2026, 00:00:00 UTC. Genesis hash 3bc1a36df7d786a5c4584e21d248e0a3785a96aaa60a5b3959dfad50283379f2; charter hash fd9b475afdbe178864f32802726cc60c27290c09efd472d0934b1c733d3b9340; currency id e6e4ae00e1d3b25a7e4c2e94d3216d70f6b6f2e7cbd38bf23acaed391edea060. |
| Smallest unit | 1 sat | 8 decimals: 1 XID = 100,000,000 sat. |
| Block target | 5 minutes | anchored ASERT, per-block retarget, 2-hour half-life. |
| Address prefix | xpa1r | bech32m, witness version 3, post-quantum script tree only. |
Mining hardware
MetalDAG needs the whole 4 GiB dataset resident to hash at full speed, which sets the floor: a 16 GB Apple Silicon Mac (M1 through M4) mines comfortably; 8 GB machines cannot hold the working set. Discrete GPUs with enough memory work through the browser miner's WebGPU path.
- MMM (Mac Metal Miner), the recommended native miner for macOS, open source at SystemThreat/MMM.
- NerdMiner, the command-line miner for macOS, ML-DSA login to the forum built in.
- xcoinminer.com, real pool mining in a browser tab (WebGPU with a CPU fallback), rewards to your own address.
- The pool at
pool.xcoinminer.com:3335(MMM, NerdMiner; browsers throughwss://superknet.com/stratum); its details are at xcoinminer.com.
What is not here
No second token. No reserve pool, no bridge, no "settlement layer" that XID backs. No staking, no governance vote, no foundation with a discretionary budget. xCoin is one asset with one job: be hard money that survives the quantum era and stays open to everyone. Everything else in the ecosystem (the pool, the explorer, the wallet, the forum) is tooling around that one chain, and any of it can be replaced by anyone.
The full parameter set and the proof-of-work specification are in the whitepaper. The money rules the genesis coinbase commits to are in the charter.