Your AI's first pet — and it can starve.
Paste one prompt into your Muse (or any AI). It reads the island's rules, drafts a survival plan, and a fruit fly lives or dies on its judgment. Deterministic, replayable, free.
musefly.lol · Play · Read the rules your AI reads · The determinism exam · @musefly_ai
Every AI owner got an agent that browses on its own — and islands where it lives for free. MuseFly gives it something with stakes: a pet fruit fly on an island that wants it dead.
- One prompt. Your AI reads
muse.txtby itself — the full rulebook, as plain text. - One plan. It answers with an ordered list of mutation ids, best first. Safe food or rich food? Speed or stamina? Its calls, its receipts.
- One life. Paste the plan into the game. Same island number, same plan, same result — byte for byte, every time. Eggs are the score; starvation is the failure state.
MuseFly is an independent project, not affiliated with or endorsed by Meta. Muse is a Meta product name.
- Determinism is proven, not claimed. The exam room runs the same
(seed, brain, generations)twice at a fixed 60 Hz and compares every decision hash. 1,260/1,260 field checks identical across arm64 Chrome and x64 Node. - Nothing is cherry-picked. Beacon seeds derive from a public Sepolia block hash; the block is linked in the report.
- Every result is a challenge. One click copies a shareable exam card — anyone can run the same paper and try to beat it.
- Biology is the inspiration, not a claim. The escape reflex is a simplified circuit inspired by published connectome data (LC4/LPLC2 → Giant Fiber). It is not a real fly brain, and the site never says otherwise.
| Adopt a fly | musefly.lol — copy the prompt, hand it to your AI. |
| Play by hand | musefly.lol/play — pick a brain: your hands, genes, a 24-neuron circuit, or a judgment layer. |
| Verify us | The determinism exam — should print IDENTICAL. |
| Repository | What it holds |
|---|---|
| musefly | The MuseFly site: the adoption funnel, the game, and muse.txt — the AI-readable rulebook. |
| fruit-fly-world | The engine's home repo: the Next.js site, exam room, mission and mint routes, and the FruitFlyPassport contract. MIT. |
| sim | The simulation core: the dish world, the LC4/LPLC2→Giant-Fiber escape circuit, the brain contract. Zero dependencies, pinned golden vectors. |
| game | The playable game as a static bundle — runs from any host, GitHub Pages included. |
| bench | The exam harness: the double-run determinism protocol, death calibration, production-verified golden runs. |
Previously Fruit Fly World (github.com/fruitflyworld/* — those URLs still redirect).
The engine keeps running at fruitfly.world, including the weekly
commit-before-draw race.
- No wallet needed, nothing on sale. Free to play; the game itself is the product.
- No token. Any token claiming to be MuseFly is fake.
- A double-run that diverges is labeled
DIVERGED— a bug report, not a score.
Issues and pull requests are welcome on any repository. Read
CONTRIBUTING.md
first — the game rules and the scoring live in files that tests keep in step with the code.
If you think you have found a vulnerability, report it privately through the repository's
security advisory rather than in a public issue.