// HACKER NEWS — CYBERSECURITY
A 3D fruit fly on macOS desktop powered by the real FlyWire connectome
A 3D fruit fly that lives on your macOS desktop — driven by a live spiking
simulation of the real FlyWire
connectome. It walks across your windows, grooms, sleeps, and decides to flee
your cursor with the same neurons a real fly uses.
The fly's brain window: 23,210 real neuron soma positions from FlyWire v783,
with live spikes flashing at real neuron locations. The two glowing yellow
markers are the Giant Fibers — the escape command neurons. Click any region
to stimulate it.
The body itself is procedural (FlyWire is a brain connectome — no body
geometry exists), with a tripod gait, visible wing-beat, altitude-scaled
flight, grooming, and sleep postures.
Requirements: macOS 13+, Xcode Command Line Tools (Swift 5.9+).
No permissions or entitlements needed — everything it senses
(cursor, window frames, clicks-as-taps, thermal state) is permission-free.
A 🪰 item appears in the menu bar; quit from there. The fly wanders your
desktop on a transparent, click-through overlay — it never intercepts your
mouse or keyboard.
The brain window is interactive: hovering pauses the rotation; clicking a
region "optogenetically" stimulates the ~60 nearest circuit neurons for
400 ms. The fly's reaction is whatever the real network does downstream —
click the Giant Fiber and it escapes; click DNg11 and it grooms; click one
side's DNa01/02 and it turns.
The loop also closes body→brain: the gait rhythm feeds the circuit's real
ascending (proprioceptive) neurons in phase with the legs, and fast cursor
motion stimulates its sensory (wind) partners.
data/ ships with compact derived files. To rebuild them from the raw
FlyWire Codex dumps (~60 MB download):
Honesty section: the connectome gives wiring, not physiology. The LIF
dynamics, neurotransmitter signs (ACh+, GABA−, Glu−), the gap-junction boost
on LC→GF and wind→GF (documented electrical coupling), synaptic delays, and
the sensory transduction (cursor → looming value) are standard modeling
choices layered on the real graph. Everything downstream of the sensory
neurons — who connects to whom, and how strongly — is FlyWire data.
Code is MIT. The files in data/ are derived from FlyWire (FAFB v783) and
are CC BY-NC 4.0 — see data/DATA_LICENSE.md.
If you use this, cite: