# Heatmap (Lumen Halo): prompt.md (v1.0.0)

- id: `lumen-heatmap` · version 1.0.0 · component · pro (All-Access)
- category: Charts
- build: Base UI (one set of files; its dependencies follow the build)
- install (this build): `npx shadcn@latest add @beautiful-ui-pro/lumen-heatmap`
- npm dependencies: recharts@^3
- registry dependencies: utils, @beautiful-ui/lumen-chart, @beautiful-ui/lumen-stat, https://beautiful-ui.dev/r/lumen-foundation.json
- docs: https://beautiful-ui.dev/components/lumen-heatmap
- The install command carries everything this item needs (files, CSS, tokens, npm and registry dependencies). Prefer it to copying source by hand.

A grid of lit cells for two categories by one measure (day × hour, cohort × week). Cells light in proportion; zero is a faint cell and missing is hatched, so they never look alike; diverging scales split around a midpoint in two colours; arrow keys walk the grid with a spoken readout.

## Build it
- Stack: React 19 (`ref` is a plain prop), TypeScript, Tailwind CSS v4 utilities, a shadcn-initialised project with the `@/*` alias.
- Packages: `recharts@^3`.
- Files: `components/ui/lumen/charts/heatmap.tsx`, `components/ui/lumen/charts/cartesian.tsx`.
- Registry dependencies, installed with it automatically: shadcn `utils` (cn), `lumen-chart`, `lumen-stat`, `lumen-foundation`.
- Builds: one set of files for both, but its dependencies come in Base UI and Radix builds. Install the one that matches the project (see Install): a free item's bare URL installs the Base UI build of it and its dependencies.
- Exports to keep: `Heatmap`, and every exported type.
- CSS: the install merges this item's rules (the registry `css` field) into your global stylesheet, in `@layer components`, and adds the lumen foundation (tokens, keyframes, motion levels) once. Nothing to import by hand.
- Re-running `add` (or `--overwrite`) re-applies those rules: put overrides in your own CSS, never in the installed rules.
- Tokens: retheme with the `--lumen-*` custom properties (`--lumen-accent`, `--lumen-accent-text`, `--lumen-bad`, `--lumen-bad-text`, `--lumen-focus`, `--lumen-good`, `--lumen-good-text`, `--lumen-hairline`, `--lumen-ink`, `--lumen-muted-ink`, `--lumen-series-1`, `--lumen-series-2`, `--lumen-series-3`, `--lumen-series-4`, `--lumen-series-5`, `--lumen-series-6`, `--lumen-warn`, `--lumen-warn-text`); this item's CSS also reads `--lumen-font-mono`, `--lumen-font-sans`, `--lumen-radius-k`. Never add Tailwind colour classes inside the component.

```tsx
import { Heatmap } from "@/components/ui/lumen/charts/heatmap";
```

## Parts

| Part | data-slot | What it is for |
|---|---|---|
| `Heatmap` | — | The plot, legend, readout, states, summary and table. |

## Sound
- Keep every `data-slot` and `data-sound` attribute: the sound layer reads them.
- Installing this item adds no audio. Nothing plays until the app mounts `GlassSoundProvider` once (install: `npx shadcn@latest add https://beautiful-ui.dev/r/glass-sound.json`, import from `@/components/beautiful-ui/glass-sound`); `GlassSoundToggle` is its mute control. Without a provider the audio engine never loads.

## Match the original
- Read `components/ui/lumen/charts/heatmap.tsx`, `components/ui/lumen/charts/cartesian.tsx` as the reference implementation before changing or recreating anything, and match it: sizes, colours per theme, motion timings, copy and behaviour.
- If you deviate (a prop you can't honour, a style you changed, a dependency you swapped), say so in your reply, part by part.
- Keep the accessibility contract, the keyboard map and the motion levels listed below.

## Use it when
- heatmap, calendar heatmap, day by hour, cohort grid, matrix, activity, usage by time, Lumen
- Patterns across two categories: when things happen, which cohorts retain

### Not when
- Exact values to compare side by side: use Bar
- A single series over time: use Line

## Mistakes
- Keep data and config stable (outside the component, or memoised)
- Say what zero and missing mean for your data; the chart keeps them apart

## Usage

```tsx
import { Heatmap } from "@/components/ui/lumen/charts/heatmap";

<Heatmap data={sessions} x="hour" y="day" value="sessions" xOrder={hours} yOrder={days} />
```

## Props

| Prop | Type | Default | What it does |
|---|---|---|---|
| `motion` | `"full" \| "subtle" \| "off"` | `"full"` | full: cells drop into place on entry; subtle and off skip it (reduced motion always does). |
| `data / x / y / value` | `Row[] / field / field / field` |  | Rows with the column category, row category and measure. |
| `xOrder / yOrder` | `string[]` |  | Column and row order (default: first appearance). |
| `valueFormat` | `StatFormat \| (n) => string` |  | Numbers in the readout, scale and table. |
| `scale / midpoint` | `"sequential" \| "diverging" / number` |  | Diverging splits around the midpoint (default 0) in two colours. |
| `color / negativeColor` | `string` |  | High (and positive) colour, and the negative colour. Default: the theme's accent and bad colours (--lumen-accent, --lumen-bad); under lumen-inherit, your --chart-1 and --destructive. |
| `xLabel / yLabel` | `string` |  | Names for the table and readout. |
| `cellHeight` | `number` |  | Cell height in px (default 28); width follows the container. |
| `loading / error / emptyText / label` | `…` |  | As every Lumen chart. |

Full docs: https://beautiful-ui.dev/components/lumen-heatmap

## Customising
- Motion: `motion="full"` (default) | `"subtle"` | `"off"`. prefers-reduced-motion is always respected.
- Colours: set the `--lumen-*` tokens on `:root`, or on a container with the `lumen-scope` class to retheme one area. Add the `lumen-inherit` class to follow your shadcn palette instead (`--chart-N`, `--destructive`).
- Dark mode follows the `.dark` class on an ancestor (the shadcn and next-themes convention).
- Update later by re-running the install with `--overwrite` (review the diff if you edited it). Changelog: https://beautiful-ui.dev/r/changelog.json

## Keyboard

| Keys | Action |
|---|---|
| Arrows | Move between cells; the readout says the cell |
| Home / End | First or last cell in the row |
| Tab | Into and out of the grid (one tab stop) |

## Motion inventory

| Interaction | What moves |
|---|---|
| Enter | Cells drop into place along the diagonals, block by block (motion="full") |
| Change | Cells cross-fade to new values |
| Hot cells | The top values glow softly |

## Accessibility contract (preserve when editing)
- A labelled figure with a one-sentence summary and the full data table for screen readers
- States (loading, empty, error) are said in words

## Install

```bash
npx shadcn@latest add @beautiful-ui-pro/lumen-heatmap
```

Pro item: needs the `@beautiful-ui-pro` registry in `components.json` and `BEAUTIFUL_UI_TOKEN` in `.env.local` (https://beautiful-ui.dev/account). Setup: https://beautiful-ui.dev/docs/pro. Your components.json `style` picks the build: radix-*, new-york and default get Radix, base-* gets Base UI.

## Credits
- Built on shadcn/ui charts conventions (https://ui.shadcn.com/charts)

The lumen foundation (the tokens listed above, keyframes and motion levels) installs once with the first component; its CSS is public at https://beautiful-ui.dev/r/lumen-foundation.json.