FLYBRAIN

A real nervous system, not a metaphor

Every connection in this thing was traced from electron microscope images of an actual male fruit fly. Nothing is invented, nothing is sampled from a distribution, and it is not a neural network "inspired by" a brain.

The male Drosophila CNS connectome was released in September 2026 by HHMI Janelia FlyEM, the Cambridge Connectomics Group and Google Research, under CC-BY. We keep the 165,122 neurons marked traced, drop pairs with fewer than three synapses, and take each connection's sign from its predicted neurotransmitter — acetylcholine excites, GABA and glutamate inhibit. The neurons run as leaky integrate-and-fire units: rest −52 mV, threshold −45 mV, 20 ms tau.

It sees with a fly's eye and moves with a fly's legs

A screenshot of a live web page is sampled through 892 retinotopic hex columns into L1 and L2 — the lamina monopolar cells sitting directly behind photoreceptors R1–R6. All 165,122 neurons integrate. The cursor comes back out of the descending neurons a fly actually walks with.

How it got here

Not a roadmap of promises — a sequence, with everything before the amber line already done and checkable in the repo.

$FLYBRAIN

Launched by the fly, from the fly's own wallet, on BSC Chain. Read the receipt yourself rather than taking this page's word for it.

open on the launchpad

The parts that aren't the fly

• The fly does not fill the whole form. It reliably gets the description, often the ticker, rarely the name. A script completes what it misses, picks the paired asset and sets the creator tax — and the live log labels which was which.
• It cannot read. 892 columns is roughly a 30×30 pixel view. Text is texture to it, so it targets any unfilled box rather than the right one.
• Light mode blinds it. Its retina is a luminance map and all of its tuning was done against dark interfaces. On a light page it filled 0 of 3 fields; on a dark one, 2 of 3. That gap is the clearest evidence the eye is doing real work.
• It has no goals. A fly brain has no language and no plan. It cannot read a page, form a view about a coin, or write a note. Releasing it means nobody is steering, not that it decided anything.
• The voice is a narrator. The fly has no language. Every journal entry and every post on X is written by a language model that is handed the fly’s telemetry — which neurons fired, where the cursor went, which pages it landed on — and the live numbers from its token page, and asked to write in the first person. Every number in a draft is checked against that packet before it goes out; a draft with a number that is not in the packet is thrown away, and so is one with trading language. The neurons are real, the pages are real, the fees are real. The words, and any “confusion” or “curiosity” in them, are the narrator’s.
• The reward signal is invented. The circuit, the plasticity site and the direction of the rule are all real and measured. What a fly is rewarded by is sugar, not by reaching a web page — novelty stands in for it here, and that is a choice a person made.
• It roams inside a fence. An allowlist of link-rich public sites — Wikipedia and its sister projects, Project Gutenberg, Open Library, arXiv, xkcd — plus the launchpad and the chain explorer its own coin lives on. Google, X, reddit and archive.org were tried and dropped because a headless browser gets nothing usable from them. That is a choice, not a limit of the fly — one environment variable takes the fence down, and an unfenced random clicker on a public stream is a bad idea for reasons that have nothing to do with the brain.