Algorithmically Generated NFTs on the X1 Blockchain
X1 Cats is a collection of 25,600 unique digital cats minted on the X1 blockchain. Every cat is generated entirely on-chain at the moment of minting — no pre-made images, no off-chain randomness, no artist decisions. The cat you get is determined by the blockchain itself.
When you click Mint, the program running on-chain does the following in a single transaction:
Generates a hash. The program combines several sources of entropy that nobody — not the user, not the team — can predict or control: the current slot hash (a fingerprint of recent blockchain activity), the current timestamp, and a unique identifier tied to your wallet and mint position. These are fed through a double-round SHA-256 function to produce a 32-byte hash.
Derives your cat's identity. The first 5 bytes of that hash become your cat's CatID — a 10-character hex string like 0173cc5daf. This ID encodes everything about your cat: its colours, its pose, its expression, its pattern, and whether it has a special background. The same CatID will always render the same cat, forever.
Checks for duplicates. The program scans the full mint history on-chain. If your hash happens to produce a CatID that already exists, the mint is rejected at no cost to you. Just try again in the next slot — a new block means a new hash.
Classifies your cat. The program reads specific bytes from the hash to determine traits: facing direction, expression (smiling, grumpy, pouting, or shy), coat pattern (pure, tabby, spotted, or tortie), and pose (standing, sleeping, pouncing, or stalking).
Checks for Genesis. The last three bytes of the hash form a number. If that number is prime — and passes an additional 1-in-8 filter — your cat is classified as Genesis: the rarest tier, capped at 256 cats across the entire collection. At roughly 0.8% of mints, Genesis cats are scarce enough that the full 256-cat cap is not expected to be reached before the collection sells out. Statistically, around 205 Genesis cats will be discovered across all 25,600 mints, leaving approximately 51 Genesis cats permanently undiscovered — sealed within hashes that were never rolled. Once the cap is reached, the primality check is skipped for all subsequent mints.
Assigns a background. Standard cats may receive a special coloured background depending on byte sequences found in the hash: X1 Blue (#0168e5) if the hash contains 0x58 followed later by 0x31; XEN Light (#90caf9) if it contains 0x58 anywhere; BTC Orange (#f7931a) if it contains 0x42. X1 takes priority. Genesis cats always have a plain dark background.
Mints the NFT. The program creates a standard Solana NFT (SPL Token + Metaplex metadata) and sends it to your wallet. Metadata is set as permanently immutable — neither the team nor any future holder can alter the name, image, or traits. The supply is sealed at exactly 1 token per CatID.
Collects the mint fee. The fee is transferred to the treasury last — only after every step above has succeeded. If anything fails, you are not charged.
| Tier | Supply | Price |
|---|---|---|
| Standard | 25,344 | 0.25 XNT |
| Genesis | up to 256 | 4.00 XNT |
| Total | 25,600 |
Note: The Genesis cap of 256 is a maximum, not a guaranteed mint count. Based on the 0.8% discovery rate, roughly 205 Genesis cats are expected to be found by the time the full collection is minted. The remainder will exist only as undiscovered possibilities — hashes that were never rolled.
Each cat is defined by 6 binary trait dimensions derived deterministically from its CatID:
| Trait | Options |
|---|---|
| Facing | Left · Right |
| Expression | Smiling · Grumpy · Pouting · Shy |
| Pattern | Pure · Tabby · Spotted · Tortie |
| Pose | Standing · Sleeping · Pouncing · Stalking |
| Pale | Yes · No |
| Background | None · X1 Blue · XEN Light · BTC Orange |
Genesis cats additionally carry the rarest trait of all: a plain dark field that marks them as provably prime.
Each cat is rendered as a pixel-art SVG, generated on-demand from the CatID using the same algorithm that originally defined MoonCats — adapted and re-implemented for X1. The colour palette, body shape, and proportions are all derived from the 5-byte CatID with no randomness at render time. The same CatID, rendered anywhere, produces exactly the same cat.
X1 Cats is an independent project and is not affiliated with Ethereum MoonCats or Acyclica. This document is for informational purposes only and does not constitute financial advice. Digital assets carry risk — always do your own research.