A simulated fruit-fly brain (FlyWire connectome) plays Game Boy games on a 24/7 stream.
Find a file
acamilo 18e16819ca docs: section 12.9, and rows 38 to 41 of the trap audit
The rung-9 forest review: what was live, the mechanism of all three
observations, the audit rows, and the trap hunt before and after from the
release container's own checkpoint.

The hunt is brain-driven rather than stubbed, which is legitimate here and
was not for sections 13 and 14: this branch adds no macro type, so no
population is re-dealt and the two arms differ in the macro code alone.
Distinct tiles 216 to 286, windows flagged 70 of 73 to 61, windows under
four tiles 21 to 5, BACK starts with no list open 175 to 0, MOVE n starts
36 to 68.

Four residuals are named rather than buried: BACK is still 359 starts of
830 over open lists, which is row 34's contract; a NEXT/BACK two-cycle
closes the run inside one battle, from a move list whose cursor the seam
cannot place on its opening frames; a window spent in a battle is flagged
by the tile rule whatever happens in it; and the THROW BALL precondition
is inert in this run because the save carries a party of one.

Row 41 is the loop behind this one: in the before arm the fly answered the
nurse's box YES 474 times on one tile of a Pokemon Center for the last
eight brain minutes of the run. The after arm never enters it, so it is
neither reproduced nor fixed here. It is the next thing to measure.
2026-09-22 04:09:05 +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: section 12.9, and rows 38 to 41 of the trap audit 2026-09-22 04:09:05 +00:00
infra docs: section 12.9, and rows 38 to 41 of the trap audit 2026-09-22 04:09:05 +00:00
packages flybrain v0.4.0: public tree (history retained privately) 2026-09-21 15:09:46 +00:00
services tests: the rung-9 forest checkpoint, on the cartridge 2026-09-22 03:28:28 +00:00
tools flybrain v0.4.0: public tree (history retained privately) 2026-09-21 15:09:46 +00:00
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CLAUDE.md flybrain v0.4.0: public tree (history retained privately) 2026-09-21 15:09:46 +00:00
CONTRIBUTING.md flybrain v0.4.0: public tree (history retained privately) 2026-09-21 15:09:46 +00:00
LICENSE flybrain v0.4.0: public tree (history retained privately) 2026-09-21 15:09:46 +00:00
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Makefile flybrain v0.4.0: public tree (history retained privately) 2026-09-21 15:09:46 +00:00
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README.md flybrain v0.4.0: public tree (history retained privately) 2026-09-21 15:09:46 +00:00
ROM-POLICY.md flybrain v0.4.0: public tree (history retained privately) 2026-09-21 15:09:46 +00:00

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.