A simulated fruit-fly brain (FlyWire connectome) plays Game Boy games on a 24/7 stream.
Find a file
acamilo cf757af510 test(flybus): assert the example's output, and split the frame measurement up
The guide's first deliverable is one small program with a counter RPC, a pub/sub
observer and a frame artifact held past its message object. examples/demo.rs was
already that; its body moves into run(), which returns the lines it prints, so
tests/example_demo.rs can assert all seven of them. The counter now uses the
spec's own example.counter / Counter.Increment / {"amount": 1} and pins the
registration it discovered, and the example prints the router's root count while
the frame is held and after the last handle goes, so the lifetime it
demonstrates is visible rather than implied. cargo run -p flybus --example demo
prints the same lines.

tests/perf.rs reports what BUS-03 and bus-v1 section 11.7 actually ask for.
Allocate, the producer's copy into staging, the router's seal copy, publish
admission, the RPC round trip and a consumer's readback are six separate
percentile lines instead of one. The router gets its own two-thread runtime
whose threads carry a distinct name, and per-thread CPU is sampled from /proc by
that name, so router CPU is separable from the clients' in the same process.
Store bytes, outstanding roots and queue lengths are reported live as well as
peak.
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.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 Merge feat/flybus: the flybus crate (Flybus v1 draft) replayed from the archive, with a design index 2026-09-22 11:02:31 +00:00
infra docs: section 12.11, and rows 44 to 47 of the trap audit 2026-09-22 09:07:00 +00:00
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services test(flybus): assert the example's output, and split the frame measurement up 2026-09-22 12:01:43 +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.