A simulated fruit-fly brain (FlyWire connectome) plays Game Boy games on a 24/7 stream.
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acamilo 80325c8d57 macros: a cursor step waits for the list it was built for
THROW BALL on the cartridge was 63 starts and 63 `blocked`, mean sixty-nine
frames: the cursor to ITEM, the A that confirms it, the twenty settle frames,
and then a refusal on the very next frame. Red keeps one cursor for every menu
in the game, the bag takes longer than twenty frames to draw, and `listing` was
still answering for the battle *menu* -- four entries, max 3. A ball whose bag
index was above that read as off the end of the list and the step gave up at
once; one inside it was walked for by pressing UP and LEFT at the battle menu,
which is the blind pressing section 4 forbids.

So a Listing now says which list it is (ListKind) and a cursor step says which
list its target indexes into. A step whose list is not up waits exactly as it
waits for a list that reports no cursor at all, and takes its press order and
its budget from that list on the first frame it accepts input rather than from
whatever was up when the script was built. A confirming press that has already
begun still finishes: the press is what answers the list, so the cartridge is
already drawing the next one while it is issued.

The crossings are named: FIGHT and ITEM and PKMN and RUN over the battle menu,
a move slot over the move list, a bag index over the bag, a party slot over the
party list. A shop's own screens are one list and stay as they were.

The fake gained the one thing it could not express -- a list that takes frames
to draw -- and two of its fixtures had FIGHT and a potion opening nothing at
all, which is how they passed while the cartridge could not.
2026-09-22 08:06:42 +00:00
.forgejo/workflows flybrain v0.4.0: public tree (history retained privately) 2026-09-21 15:09:46 +00:00
.github/workflows flybrain v0.4.0: public tree (history retained privately) 2026-09-21 15:09:46 +00:00
apps/stage stage(describe): the public repo URL on the card 2026-09-22 02:08:31 +00:00
data/fafb-v783 flybrain v0.4.0: public tree (history retained privately) 2026-09-21 15:09:46 +00:00
docs docs: v0.4.3 status 2026-09-22 06:18:44 +00:00
infra Merge fix/loop-20260922T0459: NEXT never on a pad with an input-accepting cursor; MOVE 1 is the main menu backstop; the bag is the fly's turn 2026-09-22 06:18:34 +00:00
packages flybrain v0.4.0: public tree (history retained privately) 2026-09-21 15:09:46 +00:00
services macros: a cursor step waits for the list it was built for 2026-09-22 08:06:42 +00:00
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flybrain

A simulated fruit-fly brain that plays video games. A connectome-constrained spiking network reads the screen, its population rates become controller inputs, and a scalar reward nudges a bounded set of Kenyon-cell to MBON gains.

The library is @flybrain/brain in packages/brain. It holds the connectome dataset format, the LIF kernel, the plasticity rule, the population-rate readout and the activity-map geometry. It holds no game, no emulator and no reward rules: those belong to whatever embeds it.

Workspace layout

Path Contents
packages/brain the library (@flybrain/brain)
data/fafb-v783 FlyWire-derived browser artifacts (CC BY-NC 4.0)
tools/ the Python builder that regenerates data/ from official Codex exports
docs/ overview, dataset format, model, plasticity, readout, integration, limitations, verification
services/flysim the Rust service: brain, emulator, snapshot feed, control API, checkpoints
apps/ planned: one directory per game demo
infra/ planned: deployment for the 24/7 stream (see docs/streaming-plan.md)

Quick start

npm ci
npm test
npm run typecheck

76 tests, about 7 seconds. There is no build step. npx tsx packages/brain/examples/node-random-frames.ts 60 runs the full 139,255-neuron brain with the Game Boy readout on noise frames in plain Node (about 0.9x Game Boy real time single-threaded on a WSL laptop).

Usage

import { NeuralAgent, gameboyDecoderConfig, toButtonMask } from '@flybrain/brain';
import { loadBrainDatasetFromDir } from '@flybrain/brain/node';

const dataset = await loadBrainDatasetFromDir('data/fafb-v783');
const agent = new NeuralAgent(dataset, { decoder: gameboyDecoderConfig() });
agent.warmup(firstFrame);                        // 2,500 ms with plasticity off, then calibrate

// every emulator frame:
const { active } = agent.tick(framebuffer, {     // RGBA 160x144 by default; any size via config
  rewards: [{ value: 0.5 }],                     // scalar rewards your game adapter detected
  boot: !inGame,                                 // relaxes Start/Select throttling on title screens
});
emulator.setButtons(toButtonMask(active));

const checkpoint = agent.exportState();          // bit-exact resume, validated on import

The lower layers (LifNetwork, RewardModulatedStdp, PopulationDecoder) are exported too for hosts that want to run the loop themselves.

integration.md has the full per-frame loop, the fractional frame timing and the checkpoint contract.

Documentation

  • Overview: the pipeline, the layer map and the design principles.
  • Dataset format: artifacts, CSR layout, weight encoding, every role and its count, fingerprinting, regeneration, license.
  • Model: the 1-ms LIF kernel step by step, every default constant, the retina projection, the RNG, state export and version strings.
  • Plasticity: edge selection, the eligibility and reinforcement equations, statistics, topology hash and the explicit non-claims.
  • Readout: scores, exclusive groups, pulse channels, the blocked-direction cooldown, the Game Boy preset table and checkpoint versions.
  • Integration: what a game must provide, the Pokemon Red integration as a worked example, and a sketch of a platformer adapter.
  • Limitations: what is not claimed, what is unproven, measured throughput.
  • Verification: the oracle-test strategy and what each test file covers.
  • Streaming plan: headless capture, Twitch, VM design and the phased plan for a 24/7 stream.
  • Artifact builder: how to regenerate and verify data/fafb-v783.
  • Data attribution: source, license and citations.

Provenance

The network, plasticity rule, readout, FlyWire pipeline and activity viewer were extracted from the fly-plays-pokemon prototype so several game demos can share one core. The default configuration reproduces that prototype's kernel bit for bit, and verbatim copies of its modules live in packages/brain/tests/legacy/ as oracles. Built with Astra.

Licensing

The data/fafb-v783 artifacts are derived from the FlyWire FAFB public Codex v783 exports and are licensed CC BY-NC 4.0. That is a non-commercial license, so a commercial demo needs a different data source or separate permission. Citations and the list of modifications are in data/fafb-v783/ATTRIBUTION.md.

No license has been chosen for the code in this repository yet.

ROMs and save states never enter this repository.