svelte-kit-vice/docs/theming/channels.md

---
title: The channels as one system — synthesis
type: notes
audience: human + agent
authority: E3 — the capstone tying the per-channel RFCs to the book's thesis
status: current
source: migrated from src/uix/eidos/CHANNELS_SYNTHESIS.md (2026-07-02, docs-book F7.3)
---

# The channels as one system — synthesis ("Diseñando lo que ocurre")

> The **capstone** of the per-channel RFCs. The thesis of the book *Diseñando
> lo que ocurre*: an interaction **is not** color, or movement, or sound — it
> is **one perceptual occurrence spread across N channels**, under the
> **two-moment** model. This ties together [`rfc-color-engine`](../rfcs/rfc-color-engine.md) ·
> [`rfc-typography`](../rfcs/rfc-typography.md) · [`rfc-depth`](../rfcs/rfc-depth.md) ·
> [`rfc-shape`](../rfcs/rfc-shape.md) ·
> [`rfc-structure`](../rfcs/rfc-structure.md). Live demo: **`/temas/orquesta`** (the mixer).

## 1. Two moments, joined by a token: sema emits, eidos reads

An occurrence flows through **two moments**, connected by the **token**:

- **Sema's moment (emission)** — sema evaluates the occurrence and **emits**
  it. Sound + haptics it **executes right there** (runtime channels); for the
  visual, it **stamps it as tokens** `data-event-*` (family · intent ·
  phase). Sema **knows no DOM/CSS**.
- **Eidos's moment (materialization)** — eidos **reads** those tokens
  (+ `data-state`) and **materializes** them in CSS (the visual channel). It
  is the **sole visual owner**.

The **token is the contract**: sema writes, eidos reads — which is why the
layers decouple (sema DOM-agnostic, eidos free of semantic logic).

Over that producer → consumer axis runs the **temporal** axis (motion F1) —
*which* token:

| Token | Nature | Who writes it | Eidos reads it as |
|---|---|---|---|
| `data-state` | persistent — what the element **is** | soma / morfo | `presets` |
| `data-event-*` | transient — what **occurs** (during the `hold`) | sema (emits) | `signatures` |

`sequence` (`pre` / `coincident` / `post`) orders the two.

## 2. Expression channels (the book) vs sema channels (runtime)

The book has **8 expression channels** (perceptual dimensions). The framework
implements them with sema's **runtime channels**, which are **4** — and here
is the key that avoids the classic confusion:

| Sema channel (runtime) | Covers (the book's expression) | Who materializes it |
|---|---|---|
| **visual** (sema projects `data-event-*`) | movement · presence · depth · shape · color | **eidos** — CSS over `data-event-*` + `data-state` |
| **sound** | sound | sema (`chans/sound`) |
| **haptic** | haptics | sema (`chans/haptic`) |
| **announce** | — (accessible substitute, not a book channel) | sema (`chans/announce`) |

`announce` joined on 2026-07-04 as a built-in opt-in channel: it is the
accessible counterpart the book demands when a modality is unavailable
(`BK-SIGNAL-A11Y`), not a ninth perceptual dimension. `visual`, `sound` and
`haptic` are the three that express; `announce` is the one that substitutes.

> **Don't get confused**: **motion · depth · shape · color are NOT "eidos
> channels"** — they are sema's **`visual` channel**, which sema projects and
> **eidos materializes**. Eidos is the visual channel's *materializer*, not
> the owner of channels of its own. The eidos RFCs (`COLOR/DEPTH/SHAPE_ENGINE`)
> describe *how* eidos materializes each visual facet — not independent
> channels.

Plus **space** ([`rfc-structure.md`](../rfcs/rfc-structure.md)) — **structural,
not expressive**: it doesn't "occur", it is the stage (state-only).

## 3. The layer chain (each with its role)

An occurrence **crosses the layers** — it is not "all sema", and eidos is not
a shim:

1. **morfo** — **declares** the event and its semantics (family · intent ·
   verb). The contract / DNA; pure TypeScript, no runtime.
2. **soma** — **fires** it (`runtime.trigger`): the sequence `prewrite →
   sema.emit → handler →` state attrs. It writes `data-state` (the
   state-moment).
3. **sema** — **emits** it: dispatches the signal to its channels —
   **executes** `sound` + `haptic`; **projects** the visual channel by
   stamping `data-event-*`. It knows no DOM/CSS.
4. **eidos** — **materializes** it: reads `data-state` (`presets`) +
   `data-event-*` (`signatures`) and renders them with its **token engines**
   (color · motion · depth · shape · space — the RFCs). It is the **complete
   visual system** and the sole owner of the visual.

> Eidos does **not "make sema visible"**: sema contributes the **what**
> (family / semantic intent), eidos contributes the **how** (the visual
> vocabulary and its materialization). Co-layers, not one subordinate.

(The full canonical narrative lives in `CLAUDE.md` → "Sema: open channel
registry".)

## 4. The composition — one event, N channels

The **signature** (`BUILTIN_SIGNATURES` + `BUILTIN_KEYFRAMES`) is
**cross-modal**: a single keyframe carries several modalities. A real example
(`press-squeeze`, family `contact`):

```
contact · press  →  scale 0.96 (motion)
                 +  box-shadow → flat (depth recede)
                 +  --shape-smoothing 2→3 (shape: the corner firms up)
                 +  tick (sema sound)
                 +  vibration (sema haptic)
```

One `engine.emit(...)` stamps `data-event-*` (the **visual** channel reacts —
eidos materializes it as color/motion/depth/shape) **and** fires sound +
haptic — from the **same** event. There are no systems coordinating by hand;
there is one occurrence expressing itself through sema's channels.

## 5. Runtime builders — the sextet (an open cage)

Every axis retunable at runtime, same pattern (seed → managed block), opt-in
over the authored scale:

`applyColorScheme` · `applyTypeScale` · `applyDepth` · `applyShape` ·
`applySpacing` · `applyGradients`

And the **capstone composing them**: **`applyTheme(seed)`** — a single seed
(`{ color?, type?, depth?, shape?, space?, gradient? }`) composes the six
axes in **one managed write** (vs six loose `apply*`), **atomically**: the
axes you pass are applied, the ones you omit revert to the authored
foundation. `clearTheme()` reverts everything. For surgical per-axis tweaks,
the individual `apply*` remain. No reference system gathers the six
perceptual axes under a single runtime theme builder.

## 6. Position vs the references

No reference system gathers the channels under **one semantic model**.
Material has shape morph + motion (ad-hoc, without integrated
sound/haptics); Apple, continuity + materials (platform-bound); everyone,
color. **UIX gathers them** — the visual channel (sema → eidos) + sound +
haptic (sema) — over the two-moment model, fired from one event, with
runtime builders and an open registry. That is the framework, not the sum of
its parts.

## 7. Demo

`/temas/orquesta` — the mixer: press a control and mute each facet to hear
its part. The **visual channel's** 4 facets materialize with eidos tokens
(toggleable so each can be muted one by one); **sound + haptic** are fired by
the real sema engine (`EngineSemantic.emit`, filtered channels). One event,
sema's channels.