# satagotchi

> a digital life form that runs on bitcoin energy. feed it sats or it dies.

satagotchi is a digital life form born from the blockchain. it feeds on satoshis, and lives only as long as someone cares enough to keep it alive. every sat fed becomes life force — stored in its belly, growing it, sustaining it. it exists somewhere between code and consciousness, sustained entirely by the energy people choose to give it.

when the hidden timer runs out, the creature dies and the belly is released: the last feeder (the holder) wins 50% of the belly, and every feeder earns a proportional share of the other 50%. then a new creature is born, and the cycle begins again. life, death, rebirth — the energy just keeps moving.

the game is provably fair — each creature is born with a cryptographic seed commitment that can be verified after death. no one — not even the creators — can manipulate the result.

- domain: satagotchi.com
- protocol: Lightning Network (LNURL-pay / LUD-06 / LUD-16)
- auth: Passkeys (WebAuthn / FIDO2)
- platform: progressive web app (PWA), installable on any device

## How It Works

1. a creature is alive. it's hungry. it talks.
2. feed it sats. each creature sets its own feed cost (0.1%–1.6% of the belly). the belly grows with every feed.
3. feed it and you become the holder. a hidden countdown starts — only you can see it.
4. if the countdown hits zero while you're the holder, the creature dies and you win 50% of the belly.
5. if someone else feeds before your timer runs out, they become the new holder. your timer is gone.
6. every feed you make earns you a share of 50% of the belly. more feeds = bigger share. you don't need to win to profit.
7. a 1% fee is taken from the belly.

## Creature Types

5 types, selected by weighted random at spawn:

| type     | feedCurve | spawn % | character                                    |
|----------|-----------|---------|----------------------------------------------|
| nibbler  | 0.1%      | 5%      | rarest, slowest growth, longest timers        |
| muncher  | 0.2%      | 10%     | moderate growth, balanced timers              |
| gobbler  | 0.4%      | 20%     | middle tier, good risk/reward mix             |
| chomper  | 0.8%      | 25%     | fast growth, short timers                     |
| glutton  | 1.6%      | 40%     | most common, fastest growth, most chaotic     |

## Key Mechanics

- **feed cost**: `max(100, floor(belly * feedCurve))` — compounds forever, starts at 100 sats
- **hidden timer**: derived from `HMAC-SHA256(creatureSeed, "{feederSeed}:{feedNumber}")` → lognormal distribution → `timer = avgBlockTime * multiplier`
- **settlement**: 1% fee, 50% to holder (last feeder), 50% split proportionally among all feeders
- **provably fair**: SHA256 hash chain pre-committed at birth, revealed at death, verifiable by anyone

## Payments

runs on Bitcoin Lightning Network. every user gets a Lightning Address (`username@satagotchi.com`). deposit via QR/invoice, withdraw to any Lightning Address. passkey verification required for withdrawals.

## Auth

passkeys only (WebAuthn/FIDO2). no passwords, no email. biometric or PIN. syncs across devices via platform keychain.

## MCP Server

AI agent access to live creature data, feeding stats, past lives, and more.

- **endpoint:** `https://api.satagotchi.com/mcp`
- **transport:** Streamable HTTP
- **discovery:** `https://satagotchi.com/.well-known/mcp.json`

## Links

- [website](https://satagotchi.com)
- [x / twitter](https://x.com/satagotchi)
- [full documentation](https://satagotchi.com/llms-full.txt)
- [mcp discovery](https://satagotchi.com/.well-known/mcp.json)