Box
The lowest-altitude layout primitive: surface + box-model on one element. Mirrors MUI `<Box>` (a polymorphic, unopinionated wrapper) minus the `sx` CSS-in-JS prop — Interlace uses a curated, tokenized cva variant set instead, so it cannot reopen the…
Preview
Rendered from the story the storybook (a11y) CI gate runs axe against — the preview can't show something that hasn't been verified.
Install
Two equivalent paths — the URL works in any shadcn-CLI setup; the alias works once you've registered @interlace in your components.json.
npx shadcn@latest add https://ds.interlace.tools/r/box.jsonnpx shadcn@latest add @interlace/boxBehavior
What this component does — the keyboard path, the measured colour, the text equivalent and the states it can be in. Every figure below is read out of the test or the source that enforces it by scripts/build-behavior-map.mjs, so nothing here can outlive the gate that keeps it true.
Measured contrast
packages/ui/__tests__/theme-contract-lock.test.ts ↗Every semantic colour pair this component's own source uses, measured against the shipped hexes in all 4 theme × scheme combinations. The tightest is muted-foreground on muted at 7.34:1 (harbor · light), against a floor of 4.5:1.
| Pair | interlacelight | interlacedark | harborlight | harbordark | Floor |
|---|---|---|---|---|---|
| muted-foreground on mutedcopy on a muted surface | 8.81:1 | 10.48:1 | 7.34:1 | 8.64:1 | 4.5:1SC 1.4.3 |
| muted-foreground on backgroundsecondary copy | 9.41:1 | 11.32:1 | 7.82:1 | 9.52:1 | 4.5:1SC 1.4.3 |
| muted-foreground on cardsecondary copy in a card | 9.41:1 | 10.48:1 | 8.25:1 | 8.64:1 | 4.5:1SC 1.4.3 |
| accent-foreground on accenthover/highlight face | 8.98:1 | 10.46:1 | 8.95:1 | 9.65:1 | 4.5:1SC 1.4.3 |
| card-foreground on cardcopy in a card | 19.65:1 | 15.71:1 | 18.72:1 | 14.69:1 | 4.5:1SC 1.4.3 |
Text pairs are held to 4.5:1 (WCAG 2.2 SC 1.4.3); borders, rings and chart axes to 3:1 (SC 1.4.11 non-text). Bold is the worst cell in the row — the one a brand fork has to keep an eye on.
Runtime contract
packages/ui/vitest.config.ts ↗Where it renders, how narrow it survives, and whether its lines are inside the coverage gate — three answers a consumer needs before the paste, not after the bug.
- Render boundary
server componentRenders during SSR / RSC with no hydration cost. It can be imported from a server component without pulling the page into the client.
- Minimum viewport
none declaredNo width floor: it takes the width it is given. Its container owns the layout question.
- Coverage gate
100% × 4Inside the v8 gate: lines 100, statements 100, functions 100, branches 100. A threshold under 100 only records how much you stopped caring, so there isn't one.
History
This component is at v1.1.0, first shipped in @interlace/ui 1.0.0. The version is stamped as a banner into the file the install writes, so the copy in your tree says which one you have — compare it with the number above before deciding whether to re-run the install.
No release note names this component yet. It shipped with the release above and has not changed since — see the full changelog for what moved elsewhere in the DS.
Import
2 named exports — pull the parts you need.
import { Box, boxVariants } from '@/components/ui/box';Variants
Closed prop unions enforced by class-variance-authority. See Storybook's Variants story for the rendered matrix.
- surface
- nonedefault
- card
- muted
- accent
- padding
- nonedefault
- xs
- sm
- md
- lg
- xl
- radius
- nonedefault
- sm
- md
- lg
- border
- true
- false
API reference
Parsed from the type declarations in the source — the same file the install writes into your tree, so this table can't drift from the component you get.
BoxProps
Also accepts every <div> attribute. Plus the variant props listed above.
| Prop | Type | Description |
|---|---|---|
| as | React.ElementType | Render as a different element (e.g. `section`, `article`, `ul`). Default `div`. |
Accessibility
Every story for this component is rendered headlessly and checked with axe-core (wcag2aa, wcag22aa, best-practice, ACT) on every PR. That gate has no continue-on-error, so what ships has zero known violations.
What follows is what static analysis can see. Axe cannot press a key and never sees an overlay open, so the operable-without-a-mouse claim lives in Behavior instead, where the keyboard path is replayed step by step.
- Focus + keyboard behaviour
- Native element semantics — no interaction layer to get wrong.
- Focus ring (WCAG 2.2 SC 2.4.13)
- Not focusable — no focus indicator required.
- Reduced motion
- No animation to gate.
- ARIA in the source
- None — semantics come from the element or the Base UI primitive rather than hand-written ARIA.
Examples
1 more state from the same story file.
R-rule compliance
Every primitive in @interlace/ui models to the portable 26-rule floor enforced by the componentApi ESLint preset. The cells below pin exactly where each rule applies in this file.
| Rule | Concept | Where |
|---|---|---|
| R4 | Extends native el + VariantProps | `React.ComponentProps<'div'> & VariantProps<...>` |
| R6 | data-slot | `data-slot="box"` + data-surface |
| R7 | className merged + ...rest + ref | `cn(boxVariants(...), className)` + `{...props}` |
| R8 | boolean default-false, no isXxx | `border` boolean variant; surface/padding/radius enums |
| R18 | Tailwind only | zero inline style |
| R19 | Tokens only | surface→bg-card/muted/accent; padding→p-{--spacing}; radius→rounded-{sm,md,lg} (foundation) |
| R20 | AA contrast | every surface ships its paired `text-*-foreground` |
| R25 | Server component | no hooks → no 'use client' |
Dependencies
- Base UI primitive
- Native / no Base UI dependency
- Lucide icons
- none
- NPM dependencies
class-variance-authority
- Registry dependencies
Source
The full implementation — components/ui/box.tsx once installed.
import * as React from 'react';
// @interlace/box v1.1.0 — Interlace design system.
// Docs, props and live preview: https://ds.interlace.tools/c/box
// What changed since: https://ds.interlace.tools/c/box#history
// Generated banner — keep it, the upgrade diff reads this version.
/**
* @interlace/ui — Box
*
* The lowest-altitude layout primitive: surface + box-model on one element.
* Mirrors MUI `<Box>` (a polymorphic, unopinionated wrapper) minus the `sx`
* CSS-in-JS prop — Interlace uses a curated, tokenized cva variant set instead,
* so it cannot reopen the magic-number problem LAYOUT_PHILOSOPHY closes.
* `<Card>` composes `<Box>`, never the reverse; reach for `<Section>` /
* `<Container>` for page rhythm.
*
* | Rule | Concept | Where in this file |
* | ---- | -------------------------------- | ---------------------------------------------------- |
* | R4 | Extends native el + VariantProps | `React.ComponentProps<'div'> & VariantProps<...>` |
…88 more lines…Registry JSON
The raw registry record — what the shadcn CLI fetches.