Button
The minimal-surface counterpart to [dialog.tsx](./dialog.tsx). Where Dialog exercises compound composition + portal + focus, Button exercises the variant + render-prop polymorphism + native-event passthrough surface.
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/button.jsonnpx shadcn@latest add @interlace/buttonBehavior
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 input on card at 3.11:1 (interlace · dark), against a floor of 3:1.
| Pair | interlacelight | interlacedark | harborlight | harbordark | Floor |
|---|---|---|---|---|---|
| input on cardcontrol border inside a card | 3.62:1 | 3.11:1 | 3.62:1 | 3.85:1 | 3.0:1SC 1.4.11 |
| input on backgroundcontrol border (SC 1.4.11) | 3.62:1 | 3.35:1 | 3.43:1 | 4.25:1 | 3.0:1SC 1.4.11 |
| destructive on backgrounddestructive tint on the page surface | 8.31:1 | 10.43:1 | 7.60:1 | 10.03:1 | 3.0:1SC 1.4.11 |
| destructive-foreground on destructivecopy on a destructive face | 8.31:1 | 10.43:1 | 8.02:1 | 10.03:1 | 4.5:1SC 1.4.3 |
| destructive on carddestructive tint inside a card | 8.31:1 | 9.66:1 | 8.02:1 | 9.09:1 | 3.0:1SC 1.4.11 |
| ring on backgroundfocus ring (SC 2.4.13) | 8.80:1 | 11.79:1 | 8.39:1 | 10.03:1 | 3.0:1SC 1.4.11 |
| primary on backgroundprimary tint on the page surface | 8.80:1 | 11.79:1 | 8.39:1 | 10.03:1 | 3.0:1SC 1.4.11 |
| ring on cardfocus ring inside a card | 8.80:1 | 10.92:1 | 8.86:1 | 9.10:1 | 3.0:1SC 1.4.11 |
| primary-foreground on primarycopy on a primary face | 8.80:1 | 11.79:1 | 8.86:1 | 10.03:1 | 4.5:1SC 1.4.3 |
| primary on cardprimary tint inside a card | 8.80:1 | 10.92:1 | 8.86:1 | 9.10:1 | 3.0:1SC 1.4.11 |
| accent-foreground on accenthover/highlight face | 8.98:1 | 10.46:1 | 8.95:1 | 9.65:1 | 4.5:1SC 1.4.3 |
| secondary-foreground on secondarysecondary button face | 15.58:1 | 14.51:1 | 14.63:1 | 14.04:1 | 4.5:1SC 1.4.3 |
| foreground on backgroundbody copy | 19.65:1 | 16.97:1 | 17.74:1 | 16.19:1 | 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
'use client'Hydrates. It brings JavaScript to any route that imports it — put the boundary here, not at the page.
- 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 v1.3.0, 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 { Button, buttonVariants } from '@/components/ui/button';Anatomy
Extracted from the primitive's JSDoc header. The source is the only documentation that can't drift.
buttonVariants({ variant, size })
├─ variant default | destructive | outline | secondary | ghost | link
└─ size default | xs | sm | lg | icon | icon-xs | icon-sm | icon-lg
Defaults are `variant: 'default'`, `size: 'default'`. `pagination.tsx` is
the in-repo example of styling an element rather than nesting a Button: its
`<a>` takes `buttonVariants({ variant, size })` directly. (It reaches the
function through `button.js`, which re-exports it — that path is
`'use client'`; import from this module to keep a server tree server-side.)Variants
Closed prop unions enforced by class-variance-authority. See Storybook's Variants story for the rendered matrix.
- variant
- defaultdefault
- destructive
- outline
- secondary
- ghost
- link
- size
- defaultdefault
- xs
- sm
- lg
- icon
- icon-xs
- icon-sm
- icon-lg
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.
ButtonProps
Also accepts every <button> attribute. Plus the variant props listed above.
| Prop | Type | Description |
|---|---|---|
| render | useRender.RenderProp | Replace the rendered element. Equivalent to shadcn's legacy `asChild`. Pass a `ReactElement` (e.g. `<Link href="...">`) or a render function. |
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
- Owned by @base-ui/react/use-render — focus trapping, dismissal and typeahead come from the headless primitive, not from us.
- Focus ring (WCAG 2.2 SC 2.4.13)
- Inherited from the preflight focus contract shipped in @interlace/theme.
- Reduced motion
- No animation to gate.
- ARIA in the source
aria-invalid
Examples
4 more states 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<'button'> & VariantProps<typeof buttonVariants>` |
| R7 | className merged + ...rest + ref | `cn(buttonVariants({ ... }), className)` + `{...props}` + `useRender` |
| R8 | No `isXxx` prefix | All variant keys (`variant`, `size`) follow MUI naming, not `isXxx` |
| R9 | Native onClick stays native | `onClick` passes through `{...props}` — never wrapped in a bespoke name |
| R12 | Reuse over wrap | The `render` prop lets consumers replace the rendered element entirely |
| R13 | Ecosystem first | `useRender` from `@base-ui/react/use-render` owns slot rendering |
| R17 | API parity | Mirrors shadcn/ui Button + Base UI's `useRender` slot — no deviation |
| R18 | Tailwind only | Zero inline `style={{}}`; all visual classes come from `buttonVariants` |
| R19 | Tokens only | `buttonVariants` lives in [button-variants.ts](./button-variants.ts) and uses theme tokens |
| R20 | AA contrast | Variant classes target `bg-primary`/`text-primary-foreground` — token pair |
| R26 | A11y from native el | `<button>` is the native element; focus, keyboard, ARIA inherited |
| R8 | Enums, no booleans | `variant` and `size` are closed string enums |
| R19 | Tokens only | `bg-primary`, `bg-destructive`, `bg-accent`, `ring-ring/50` |
| R20 | AA contrast | every pair composited by `composite-contrast-lock` |
| R25 | Server-safe | no React import, no hooks, no `'use client'` |
Dependencies
- Base UI primitive
- @base-ui/react/use-render
- Lucide icons
- none
- NPM dependencies
@base-ui/reactclass-variance-authority
- Registry dependencies
Source
The full implementation — components/ui/button.tsx once installed.
'use client';
import * as React from 'react';
// @interlace/button v1.3.0 — Interlace design system.
// Docs, props and live preview: https://ds.interlace.tools/c/button
// What changed since: https://ds.interlace.tools/c/button#history
// Generated banner — keep it, the upgrade diff reads this version.
/**
* @interlace/ui — Button (secondary reference for the interlace-component skill)
*
* The minimal-surface counterpart to [dialog.tsx](./dialog.tsx). Where Dialog
* exercises compound composition + portal + focus, Button exercises the
* variant + render-prop polymorphism + native-event passthrough surface.
*
* | Rule | Concept | Where in this file |
* | ---- | -------------------------------- | --------------------------------------------------------------------------- |
* | R4 | Extends native el + VariantProps | `React.ComponentProps<'button'> & VariantProps<typeof buttonVariants>` |
* | R7 | className merged + ...rest + ref | `cn(buttonVariants({ ... }), className)` + `{...props}` + `useRender` |
…54 more lines…Registry JSON
The raw registry record — what the shadcn CLI fetches.