# AGENTS.md — SciFi-XZBT

Guidance for AI coding agents working in this repository.

## What this project is

A browser-only, zero-dependency **sci-fi ambient audio + visual display**. It
synthesizes starship room tone (hull drone, worp core, life support, telemetry,
alerts) with the Web Audio API and renders LCARD-styled UI, an audio
visualizer, and a procedural "observation" viewscreen on HTML canvas.

It runs by opening `index.html` in a browser. There is **no build step, no
package manager, no server, and no test suite.**

## Architecture

`index.html` loads one stylesheet and eight scripts **in a fixed order**:

```
css/style.css
js/audio.js               -> js/config.js -> js/core-animations.js -> js/visualizer.js
js/observation-bezels.js  -> js/observation-engine.js
js/midi.js                -> js/generative-experience.js -> js/app.js
```

Order matters: every file defines plain classes/objects and publishes them on
`window`; `js/app.js` runs last and consumes all of them. Do not reorder the
tags without checking the dependencies.

| File | Owns | ~Lines |
| --- | --- | --- |
| `index.html` | DOM skeleton, script/link tags | 460 |
| `css/style.css` | LCARD themes, CRT effects, palettes | 2,430 |
| `js/audio.js` | `AudioManager`, `FuturisticNoiceCancellation` + all synth classes (hull, warp, life support, telemetry, alert, Whataverse, expanded sci-fi) | 6,890 |
| `js/config.js` | `StarshipPresets`, `UniverseRegistry` — data only, no behavior | 1,170 |
| `js/core-animations.js` | `CoreAnimations` — settings-panel core animations | 220 |
| `js/visualizer.js` | `StarshipVisualizer` — spectrum + worp core canvas | 670 |
| `js/observation-bezels.js` | `ObservationBezels` — procedural SVG viewport frames per era | 270 |
| `js/observation-engine.js` | `ObservationEngine` — celestial simulation, canvas rendering, per-universe waveform | 3,590 |
| `js/midi.js` | `XZBTControlBus` (semantic control registry) + `XZBTMidiController` (Web MIDI / MIDI learn) | 170 |
| `js/generative-experience.js` | `XZBTGenerativeExperience` — optional local LLM narration and neural speech | 1,370 |
| `js/app.js` | DOM bindings, hotkeys, UI controllers, main loop | 4,440 |
| `tools/package.ps1` | Builds the standalone single-file HTML | — |
| `dist/SciFiAmbientDisplay_V<commit>.html` | **Generated output — never edit by hand** | — |

## Hard constraints

- **No dependencies.** No npm, no CDN links, no external fonts, images, or
  audio files. The packaged build must work when double-clicked while offline.
- **No ES modules.** No `import` / `export`, no `type="module"`. Scripts are
  classic globals.

### The one documented exception

`js/generative-experience.js` is the **only** file permitted to reach the
network, and it is the only file permitted to use `import`. It lazily pulls
WebLLM and Kokoro via dynamic `import()` from CDN:

```js
this.webllm = this.webllm || await import('https://esm.run/@mlc-ai/web-llm');
this.kokoroModule = this.kokoroModule || await import('https://esm.sh/kokoro-js@1.2.1?bundle');
```

The exception is bounded, and every bound is load-bearing:

- The imports live **inside** `prepareExperience()` / `prepareTTS()`. Nothing is
  fetched at parse time, so the packaged single-file build still opens and runs
  fully offline — the Generative Experience panel simply stays on STANDBY.
- Both are guarded: `navigator.gpu` is checked before the WebLLM import, and a
  failed Kokoro load falls back rather than throwing.
- No other subsystem may depend on this one. The deterministic engine stays
  authoritative; the LLM only verbalizes world state that audio.js and app.js
  already decided.

Do not widen this exception. New network use anywhere else, a static
`<script type="module">`, or a top-level `import` in any file is still a bug.
Web MIDI (`js/midi.js`) is a browser API, not a dependency, and is unaffected.
- **Publish globals explicitly.** End each file with `window.Thing = Thing;`,
  matching the existing pattern.
- **All audio is synthesized**, not sampled. New sounds are built from
  oscillators / noise / filters in `js/audio.js`.

## Where to make a change

- New room or ship preset, universe, palette → `js/config.js`
- Sound generation, oscillators, envelopes, filters → `js/audio.js`
- FNC comfort-filter behavior, source attenuation curves → `FuturisticNoiceCancellation` in `js/audio.js`
- MIDI mapping, learn flow, new controllable targets → `js/midi.js` (register targets on the bus in `js/app.js`)
- Speech profiles, prompts, LLM/TTS handling → `js/generative-experience.js`
- Spectrum bars, warp-core animation → `js/visualizer.js`
- Viewscreen frame / bezel shapes per era → `js/observation-bezels.js`
- Planets, stars, drift, observation-mode canvas → `js/observation-engine.js`
- Buttons, sliders, hotkeys, state wiring, animation loop → `js/app.js`
- Colors, layout, theme classes, CRT overlay → `css/style.css`

Presets in `config.js` follow a fixed shape — copy an existing one rather than
inventing fields:

```js
'era-room': {
  id, name, era, theme, alertType, description,
  hull:        { volume, baseFreq, filterCutoff, resonance, noiseMix, harmonicSpread },
  warp:        { volume, bpm, carrierFreq, filterCutoff, pulseShape, resonance, swirlMix },
  lifeSupport: { volume, noiseType, highpassFreq, lowpassFreq, airflowModSpeed, airflowModDepth },
  telemetry:   { volume, density, era }
}
```

## Adding a new JS file

1. Create `js/your-file.js` and end it with `window.YourThing = YourThing;`.
2. Add the tag to `index.html` **in this exact form**, positioned before any
   file that depends on it (and always before `js/app.js`):

   ```html
   <script src="js/your-file.js"></script>
   ```

   `tools/package.ps1` inlines assets by matching
   `<script\s+src="([^"]+)"></script>` and
   `<link\s+rel="stylesheet"\s+href="([^"]+)"\s*/?>`. Extra attributes, a
   different quote style, or a self-closing script tag will be silently left as
   an external reference and the standalone build will break.

## Build

```powershell
powershell -ExecutionPolicy Bypass -File .\tools\package.ps1
```

Writes `dist/SciFiAmbientDisplay_v4.html` (CSS and JS inlined). Re-run it after
any change to CSS, JS, or `index.html`. `tools/extract.ps1` is the original
extraction script, kept for reference only.

## Verifying work

There are no automated tests. Verification is manual:

1. Open `index.html` in a browser; check the console is clean.
2. Exercise the affected area — play a preset, switch era/universe, enter the
   Watch Experience, toggle FNC.
3. Re-run `package.ps1` and open the generated `dist/SciFiAmbientDisplay_V<commit>.html`
   **with the network disabled** to confirm it is genuinely self-contained. The
   Generative Experience panel must report an error and everything else must
   still work — that is the test for the exception above, not a failure.

Browser autoplay policy blocks audio until a user gesture; audio starting only
after a click is expected behavior, not a bug.

The Generative Experience needs a WebGPU-capable browser (Chrome/Edge) **and**
network access on first preparation. Absence of either is expected to degrade
quietly, never to break the console.

## Conventions and cautions

- 2-space indentation; single quotes in JS; existing brace and spacing style.
- `js/app.js`, `js/audio.js` and `js/observation-engine.js` are large. Make
  **surgical, scoped edits** — do not rewrite, reorder, or reformat whole files.
- Do not reformat or lint files wholesale; diffs should stay minimal and
  reviewable.
- Never edit anything in `dist/` — regenerate it instead.
- Preserve the offline, single-file-deliverable property in every change.

## Terminology

`Theme_Terminology_IP_Changes.md` is the authoritative rename table and applies
to **identifiers as well as display strings**. The universe id is `whataverse`,
the theme class is `theme-whataverse-tardix`, preset ids are `tardix-*`, and the
telemetry era is `'whataverse'`. Do not reintroduce the original franchise
spellings anywhere, including in comments.

`TelemetrySynth` still accepts `'who'` and `'what'` as era values purely for
backward compatibility with older presets; do not write new presets against them.