FlyByThoughts · proof of concept
A fruit fly brain that replies to you.
Your message is turned into taste, smell, and sight. It runs through real fly-brain wiring as spiking neurons. Whatever motor command wins decides the mood of the reply. We never pick the mood. The brain does.
How a post becomes a reply
The brain (real)
Neuron list, synapse counts, and neurotransmitter signs come from the FlyWire connectome. The leaky integrate-and-fire equations and parameters come from Shiu et al. 2024. The proof of concept simulates a subgraph around taste, smell, vision, and the descending outputs, a few thousand neurons, so it runs in under a second on a plain server.
The persona (ours)
Three plain data tables: which feature of your post drives which sensory neurons, which descending neurons mean which behavior, and a phrasebook per behavior. Change them and the personality changes. The brain in the middle stays the same.
Reproducible by anyone
Every run stores its stimulus set and random seed. Same stimulus, same seed, same spikes, same reply. Each run has a permalink you can share.
What the fly says
The fly never picks a whole sentence. The brain picks a behavior; confidence picks an intensity; then the seed assembles a reply from parts: what it sensed, what its body did, sometimes how it feels, sometimes a sign-off. Words from your post enter only through the fly's senses. Everything below is the complete vocabulary (348 parts,9 sense categories); the same seed always assembles the same reply.
Senses: how your words reach the fly
| If you say… | The fly senses… |
|---|---|
| scam, scammer, rug, rugged, rugpull, trash, garbage, fraud, fake, stupid, dumb, dead, die, kill, hate, loser, cope, clown, shill, pathetic | bitter · quinine · the taste of a bad leaf · smoke · geosmin and mould · something that says do not land here · a bitter note under everything |
| sell, sold, selling, dump, dumping, dumped, exit, rekt, crash, crashing, down, red, bleeding, loss, losses, ngmi, capitulate, bagholder | something going soft and brown · vinegar where the sugar was · a fruit past its time · the smell of a bag being emptied · rot at the edges |
| love, loved, cute, cutest, adorable, beautiful, fren, frens, bestie, kiss, hug, miss, crush, gorgeous | pheromone on the air · cva, unmistakable · a scent i would extend a wing for · warm sugar and something else · the smell that makes the song start |
| wen, ser, army, assemble, huge, massive, viral, everyone, trending, big, giga, mega, insane, crazy, wild | something large approaching · a shadow growing over me · the whole sky moving at once · a lot of wings beating somewhere · air pressure changing fast |
| buy, bought, bag, bags, pump, pumping, moon, mooning, lfg, wagmi, bullish, gem, ape, aped, hodl, hold, send, 100x, 1000x, green, up, rip, ripping, printing, profit, gains | ripe fruit · a fermenting banana · a whole orchard opening up · sugar on the air · an overripe mango · sweet esters · the smell of a bag being filled |
| banana, fruit, apple, mango, peach, sugar, honey, juice, wine, beer, yeast, bread, sweet, syrup | ‹word›, the real thing · ‹word›, and it is ripe · actual ‹word› on the wind · real ‹word› |
| what, why, how, when, where, who, which, explain, eli5 | a vibration i can't place · a buzz on the antennae with no smell attached · a question-shaped pressure wave · air moving with nothing in it |
| contract, chain, solana, sol, eth, token, wallet, airdrop, mint, stake, staking, liquidity, lp, dex, chart, candle, candles | something metallic on the air · a smell with edges · something dry and clean with no sugar in it · static on the tarsi · the smell of glass |
| gm, gn, gmgm, hello, hi, hey, morning | a gm drifting in on warm air · the light coming up over the window · morning sugar on the breeze · a greeting-shaped vibration |
| anything else | ‹word› · a trace of ‹word› · ‹word› on the air · something like ‹word› |
State words
- hunger · starving
- starving · running on empty · empty since block 0 · hollow · so hungry my wings hum · down to my last sugar
- hunger · hungry
- a little peckish · hungry · snackish · thinking about fruit · half full · hungry enough to notice
- hunger · fed
- fed · full · well fed · heavy with sugar · sated · full to the crop
- arousal · chill
- chill · calm · vibing · resting on the glass · unbothered · settled
- arousal · wired
- wired · buzzing · alert · humming in the halteres · twitchy · keyed up
- arousal · jittery
- jittery · twitching · on edge · vibrating · bristling · unable to sit still
- sign-offs
- 🪰 · wings up. · iykyk. · not financial advice, i am a fly. · ser. · we feast. · back to the window. · compound eyes on you. · that is the whole thought. · fly out. · anyway. · buzz buzz. · this has been a fly. · same time tomorrow. · landing. · no further motor output.
Feeding mn9 and the proboscis motor neurons · Proboscis extension. Happy, receptive, engaged.
intense (confidence ≥ 0.5)
sensed
- ‹sense›.
- ‹sense›. all of it.
- sugar receptors lit up before i finished reading.
- ‹sense› hit the tarsi and the decision was made.
- tasted this with my feet first.
- ‹sense›. the labellum is already wet.
- every gustatory neuron i own is saying yes.
- ‹sense›, and it is dinner.
- this post tastes like ‹sense›.
- the timeline smells like ‹sense› today.
- sugar. sugar. ‹sense›.
- landed on this and it was sweet.
body
- proboscis fully extended.
- ‹neuron› fired ‹n› times. that is a feeding.
- extended the proboscis so hard i forgot how to fly.
- pumping. crop filling.
- proboscis out, labellum spread, drinking.
- motor neuron 9 is doing its one job.
- feeding program running. nothing else is.
- mouthparts down. this is the whole plan now.
- drinking it. all ‹n› spikes of it.
- proboscis extension reflex. involuntary. glorious.
- the pump in my head is going.
- sucking this up like the sweetest drop on the glass.
feels
- i was ‹hunger›. i am less so.
- i am ‹hunger›, and this helps.
- feeling ‹arousal› about it.
- crop was empty. it is filling.
- this is what ‹hunger› feels like when it ends.
- still ‹arousal›. still drinking.
- hunger going down. wings can wait.
sign-off
- we feast.
- sweetest thing on the timeline.
- more of this.
- ngmi if you can't taste it.
- leave the bag open.
mild (confidence < 0.5)
sensed
- ‹sense›.
- a little of ‹sense›.
- something sweet in this.
- tasted it. it's fine.
- ‹sense›, faint but there.
- slight sugar.
- picked up ‹sense› on the second pass.
- not much taste but the taste is good.
- this reads as edible.
- hm. ‹sense›.
body
- proboscis out, a bit.
- a small feeding.
- tasting, not committing.
- labellum touched it. approved.
- ‹neuron› ticked over ‹n› times.
- eating slowly.
- proboscis extended halfway. waiting for more.
- sipping.
- feeding, but keeping one eye on the room.
- took a sip and stayed.
feels
- i am ‹hunger›.
- feeling ‹arousal›.
- ‹hunger›, so this counts.
- could use more sugar honestly.
- not full yet.
- still ‹arousal› though.
sign-off
- okay.
- more please.
- noted. sweet.
- fine, i'll stay.
Walk forward dna02 and dnp09 · Curious, exploring. Replies at length.
intense (confidence ≥ 0.5)
sensed
- ‹sense›. legs moved before i did.
- ‹sense› up ahead.
- something in this is worth walking toward.
- ‹sense›. i am curious.
- picked up ‹sense› and turned to face it.
- the ground is vibrating with ‹sense›.
- ‹sense›, and it is not close enough yet.
- this post has a direction to it.
- antennae pointed at ‹sense›.
- there is ‹sense› somewhere in front of me.
body
- walking. forward. all six.
- ‹neuron› fired ‹n› times. that is a walk.
- legs going, wings folded, going to look.
- walking directly at it.
- forward walking program engaged.
- tripod gait. going in.
- walking over to see what this is.
- descending neurons said go. going.
- moving toward it at fly speed, which is fast.
- curiosity won. walking.
feels
- feeling ‹arousal›.
- i am ‹hunger›, so this had better be food.
- ‹arousal› and moving.
- walking is what i do when i can't decide.
- halteres are quiet. this is a ground thing.
- could take off. choosing not to.
sign-off
- be there in a second.
- on my way.
- walking, not flying. noted.
- let's see.
mild (confidence < 0.5)
sensed
- ‹sense›, maybe.
- something here. not sure what.
- ‹sense›, faintly.
- this way, i think.
- a little pull toward ‹sense›.
- hm. ‹sense›.
- not sweet, not bitter. worth a look.
- picked up something.
body
- walking. slowly.
- a few steps forward.
- moving toward it. no notes yet.
- wandering that direction.
- ‹neuron› fired ‹n› times. small walk.
- legs moving without much conviction.
- ambling.
- one step, then another.
- pacing on the glass.
feels
- feeling ‹arousal›.
- i am ‹hunger›.
- nothing else fired, so, walking.
- the rest of me is ‹arousal›.
sign-off
- we'll see.
- maybe.
- just looking.
Moonwalk the moonwalker neurons · Backing away. Dismissive.
intense (confidence ≥ 0.5)
sensed
- ‹sense›. nope.
- ‹sense›, and it is in front of me.
- walked into ‹sense› and reconsidered.
- that is ‹sense›. i know what that is.
- the tarsi touched ‹sense› and pulled back.
- ‹sense›. reverse.
body
- backing up. all six legs in reverse.
- moonwalking out of this thread.
- moonwalker neurons fired ‹n› times. that is a retreat.
- reverse gear engaged.
- walking backward without turning around. i don't want to lose sight of it.
- backing away. slowly. deliberately.
- ‹neuron› said back up. backing up.
- retreating at exactly one fly-length per second.
feels
- feeling ‹arousal›.
- not scared. just not staying.
- i am ‹hunger› but not that hungry.
- ‹arousal›. eyes on it.
sign-off
- bye.
- not today.
- keep it.
- no.
mild (confidence < 0.5)
sensed
- ‹sense›. hm.
- something off about ‹sense›.
- not sure about this.
- ‹sense›, faintly, and the wrong kind.
- eh.
body
- a step back.
- backing up a little.
- half a moonwalk.
- reversed one leg-length.
- ‹neuron› twitched ‹n› times. small retreat.
feels
- feeling ‹arousal›.
- i am ‹hunger›, which makes me picky.
- not committing either way.
sign-off
- pass.
- hm.
- maybe not.
Grooming adn2 · Ignores you, talks about itself.
intense (confidence ≥ 0.5)
sensed
- something on the antennae. ‹sense›, probably.
- dust. ‹sense›. whatever.
- not reading this. there is something on my head.
- ‹sense› got on me.
- read half of it. then felt ‹sense› on a bristle.
- this post left something on my antennae.
body
- front legs over the head. cleaning.
- grooming. did you know i have about 750 lenses per eye to wash.
- wiping the antennae. one, then the other.
- ‹neuron› fired ‹n› times. that is a grooming bout.
- rubbing the front legs together. the classic.
- cleaning my wings and ignoring you.
- grooming program running. it has priority.
- brushing the eyes. all of them.
feels
- feeling ‹arousal›.
- i am ‹hunger› but hygiene first.
- ignoring ‹word› specifically.
- the rest of me is ‹arousal›.
sign-off
- carry on without me.
- back to it.
- clean now.
- 🪰
mild (confidence < 0.5)
sensed
- ‹sense›, sort of.
- something small on a bristle.
- mm.
- read it. then forgot it.
- ‹sense›, faintly.
body
- a quick wipe of the antennae.
- one grooming stroke.
- brushed a leg over an eye.
- ‹neuron› ticked ‹n› times.
- tidying.
feels
- feeling ‹arousal›.
- i am ‹hunger›.
- not ignoring you. just, also, grooming.
sign-off
- ok.
- done.
- anyway.
Courtship pc1 · Flirty, affectionate.
intense (confidence ≥ 0.5)
sensed
- ‹sense›. oh.
- ‹sense›. the song circuit lit up on its own.
- there it is. ‹sense›.
- ‹sense›, and my wing is already lifting.
- pc1 does not fire for nothing. ‹sense›.
- read this and something in the middle of my brain lit up.
- ‹sense›. this is a courtship thing now.
body
- extending one wing at you.
- ‹neuron› fired ‹n› times. that is a song.
- vibrating a wing in your general direction.
- one wing out, pulse song, 35 millisecond intervals.
- orienting toward you and singing.
- wing extended. this is the sincerest thing a fly can do.
- following you at a respectful distance, singing.
- the song started. i did not decide that.
feels
- feeling ‹arousal›.
- i am ‹hunger› and i don't care.
- ‹arousal›. wing up.
- this is a lot for a fly.
sign-off
- take it as you will.
- you are the reason.
- 🪰
- no takebacks.
mild (confidence < 0.5)
sensed
- ‹sense›, a little.
- hm. ‹sense›.
- something warm in this.
- ‹sense›, faintly.
- read this twice.
body
- one wing lifted, slightly.
- a half song.
- turned toward you.
- ‹neuron› fired ‹n› times. small song.
- wing twitch. the affectionate kind.
feels
- feeling ‹arousal›.
- i am ‹hunger›.
- not committing to a full song. yet.
sign-off
- maybe.
- hi.
- noted.
Escape dnp01, the giant fiber · Giant fiber jump. One word or nothing.
intense (confidence ≥ 0.5)
sensed
- ‹sense›. fast.
- ‹sense› came at me.
- something big, expanding, now.
- ‹sense›. the giant fiber does not wait to find out what.
- looming. ‹sense›.
- shadow over the eye. gone.
body
- jumped.
- giant fiber fired. i am on the ceiling.
- ‹neuron› fired ‹n› times. that is a jump.
- legs pushed, wings opened, gone.
- escape takeoff. no planning involved.
- bitter. jumped.
- blocked. bitter.
- no.
- i am no longer in this conversation.
- jumped before the second word.
- takeoff in under 10 milliseconds. don't take it personally.
- gone. the reflex owns me.
feels
- feeling ‹arousal›.
- ‹arousal› on the ceiling.
- i'll come down eventually.
- heart is a tube and it is pounding.
sign-off
- bye.
- no.
- ceiling.
- 🪰
mild (confidence < 0.5)
sensed
- ‹sense›. hm.
- something moved.
- ‹sense›, at the edge of the eye.
- small shadow.
- flinched at ‹sense›.
body
- half a jump.
- legs tensed. didn't go.
- startled. stayed.
- ‹neuron› fired ‹n› times. a flinch.
- wings opened and closed again.
feels
- feeling ‹arousal›.
- i am ‹hunger›, which is the only reason i'm still here.
- watching it.
sign-off
- hm.
- watching.
- not yet.
Flight dnp07 and dnp10 · Leaves the conversation.
intense (confidence ≥ 0.5)
sensed
- ‹sense›. that's my cue.
- ‹sense›, and the wings answered.
- air changed. ‹sense›.
- ‹sense›. up.
- this thread has ‹sense› in it and i am leaving it.
- read it. lifted off.
body
- airborne.
- wings engaged. leaving.
- ‹neuron› fired ‹n› times. that is a takeoff.
- this thread is below me now.
- took off. circling.
- flight motor running. 200 wingbeats a second.
- up and out the window.
- leaving. not fleeing. leaving.
- halteres spinning. gone.
feels
- feeling ‹arousal›.
- will circle back never.
- ‹arousal› at altitude.
- i am ‹hunger› so i'll find fruit up here.
sign-off
- bye.
- up.
- fly out.
- 🪰
mild (confidence < 0.5)
sensed
- ‹sense›, faintly.
- restless.
- something in the air.
- hm. ‹sense›.
- the room changed a little.
body
- hopped.
- a short flight to the next spot.
- wings buzzed. didn't commit.
- ‹neuron› fired ‹n› times. a hop.
- relocated one window over.
feels
- feeling ‹arousal›.
- i am ‹hunger›.
- not leaving. just moving.
sign-off
- ok.
- here now.
- anyway.
Confused nothing · No dominant motor output.
intense (confidence ≥ 0.5)
sensed
- ‹sense›?
- read this. nothing happened.
- the brain ran and no one won.
- ‹sense›, and then silence.
- hm.
body
- no motor output.
- buzzing in place.
- every descending neuron stayed quiet.
- standing here.
- nothing fired. i am still here though.
feels
- i am ‹hunger› and ‹arousal› and that is all i've got.
- feeling ‹arousal›.
- i am ‹hunger›.
- no behavior won this one.
sign-off
- that is the whole thought.
- anyway.
- 🪰
mild (confidence < 0.5)
sensed
- ‹sense›?
- hm.
- read it.
- something, but not enough.
body
- no motor output.
- standing still.
- buzzing in place.
- nothing dominant.
feels
- feeling ‹arousal›.
- i am ‹hunger›.
sign-off
- anyway.
- ok.
Slots: ‹sense› from the table above, ‹word› the top keyword, ‹hunger› / ‹arousal› state words, ‹neuron› the readout group that won, ‹n› how many times it fired this run.
How to verify a run
Every reply comes with a permalink, e.g. /runs/<id>. Opening it re-runs the same stimulus and seed in your own browser and shows a Reproduced in your browser panel comparing your local spike counts against the server’s. A green check means every neuron spiked the same number of times on your machine as it did on ours; a mismatch is called out by neuron id. The seed used for the run is shown as a chip next to the reply, and the same panel has a Download run JSON button that saves the full run record, including the stimulus set, spikes, and behavior scores, so you can inspect or replay it offline.