About this site — Xahmoeba

What it is, and is not

Xahmoeba is a small artificial-life experiment: a species of digital creatures whose bodies grow from a 32-byte genome through a fixed developmental process, who inherit from two parents, and who live as one population with a public lineage. The ledger is the infrastructure that keeps that population honest — who keeps which moeba, who its parents were, what chance decided at its birth — not the idea itself.

Technically it is a protocol on Xahau: one issuing account with hooks that admit breeding requests, fix each birth’s randomness from a ledger that closes after the parents are chosen, compute the child and mint it. This site is one way of looking at the result. It does not decide anything. If the site and the ledger disagree, the ledger is right and the site has a bug. The whole design, including what the issuer can and cannot do and why its account is not blackholed, is written up in the whitepaper.

Where the idea comes from

Xahmoeba does not come out of nothing, and does not claim to. Growing complex forms from small sets of rules goes back to Aristid Lindenmayer’s work on plant growth in the 1960s. Richard Dawkins’ biomorphs (1986) showed that a genome can generate a form and that a person can breed forms by choosing among offspring. Karl Sims’ Evolving Virtual Creatures (1994) is the closest ancestor: genetic instructions that describe a developmental process, interpreted into a body and its control, with mutation and crossover changing structure and not only parameters. Since 2017, projects such as CryptoKitties, Heterosis and Arborithms have made digital heredity ownable, persistent and breedable on a blockchain, each in its own way.

What Xahmoeba adds is a particular combination. The genome is neither a seed for an image generator nor a list of visual traits; it is read through developmental pathways that build one canonical body, and the renderer only visualises that body afterwards. Because of that, a child resembles its parents for reasons that can be traced locus by locus. Variation is settled once, at birth, from chance the network supplies after the parents are committed, and is inherited from then on. Nothing is marked rare in advance: a form is rare when the genetics make it hard to reach. And the founders are only the beginning — the work is the population and what its generations do, kept by many people rather than run inside one simulation.

Where the data comes from

From the ledger, and nowhere else. Every moeba is a token minted by the issuer account; the site reads the issuer's history and each token's current state from a Xahau node, and draws the animal from the genome on your device. Between visits it only reads what has happened since. This copy has a small server in front of the node, an indexer, that does the same read once for everyone and answers in a moment; it holds nothing the ledger does not, and if it is down your browser reads the node itself. Keeper tools prepare transactions for your own wallet to sign; nothing you sign passes through anyone in between.

Check anything yourself

Every moeba page shows the records the claims rest on, and the site re-does the arithmetic in front of you:

Replay. A birth is a pure function of the two parents' genomes and the recorded randomness. The moeba page runs it again on your device and says whether the recorded genome matches.
Randomness. The record names the ledger whose hash was used. That ledger closed after the request was admitted — the parents were committed before the chance that decided the child existed — and its hash is public. See where the randomness comes from.
Ownership and offers. Every token id links to the explorer, where the token's owner, sell offer and full transaction history are shown by a third party.
The hooks' hashes. They are on the issuer account, and every version that has run is on the ledger with the ledger it went live in. The source is not published. The check you can make is the replay above: this site runs the birth again from the records on the token.

This copy

A rehearsal. This copy reads a species running on the Xahau test network before its release. The population may be wiped, the issuing account replaced and the rules changed without notice, and nothing born here carries over to the release. The whitepaper says why it is done in public.

Network: Xahau testnet
Issuer account: rMmx5nHzoVJAoMTFWkgCCMrZryTaD682tr
Node: https://xahau-test.net
History from: ledger 12,545,963
Run by: xrplorer ApS — see the terms and the privacy notice

Words used here

moeba, moebas: One creature, several creatures. The species is Xahmoeba.
The issuer: The one Xahau account that mints every moeba and whose hooks run the protocol: it admits requests, takes the fees, writes the records. Nobody signs for it; its hooks wake themselves up.
Keeper: The account that holds a moeba's token. The ledger calls it the owner.
Founder: A moeba born with no parents, from ledger randomness alone. Generation 0.
Locus, allele: A position in the genome, and one of the values it can take. Every locus is present in two copies.
Fire: One wake-up of the issuer's hooks by Xahau's Cron. Each fire moves one birth one step, and is paid for from that birth's budget before it is booked.
Terms, permission: A keeper's standing statement that others may breed with their moeba, and at what price.
Fertility: The number of births a moeba can be a parent in. Fixed at birth; spent one at a time.