useTheme hook

@interlace/ui — reads and writes the theme (`data-theme`) and colour scheme (`.dark`) axes, persists to localStorage, and follows the OS when no preference is stored.

foundationclientlibv1.1.0

useTheme hook — live renderutilities-usetheme--default ↗

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.

Via shadcn URL

npx shadcn@latest add https://ds.interlace.tools/r/use-theme.json

With the @interlace alias

npx shadcn@latest add @interlace/use-theme

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

6 named exports — pull the parts you need.

Public API

import { SchemePreference, applyTheme, readStoredScheme, readStoredTheme, systemScheme, useTheme } from '@/hooks/use-theme';

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.

toggle schemeutilities-usetheme--toggle-scheme ↗

Dependencies

Base UI primitive: Native / no Base UI dependency
Lucide icons: none
NPM dependencies: none
Registry dependencies: @interlace/theme-script
@interlace/theme-tokens

Source

The full implementation — hooks/use-theme.ts once installed.

275 lines · TypeScript

github ↗

'use client';

import { useCallback, useEffect, useState } from 'react';

// @interlace/use-theme v1.1.0 — Interlace design system.
// Docs, props and live preview: https://ds.interlace.tools/c/use-theme
// What changed since: https://ds.interlace.tools/c/use-theme#history
// Generated banner — keep it, the upgrade diff reads this version.

/**
 * @interlace/ui — useTheme.
 *
 * The runtime half of the two-axis theme contract. It owns the two pieces of
 * state a user can change (which THEME, which SCHEME), persists them, and
 * projects them onto `<html>` in exactly the shape `styles/index.css`
 * expects:
 *
 *   theme   → `data-theme="<name>"`   (absent = the default, which IS `:root`)
 *   scheme  → `class="dark"`          (shadcn / next-themes canon)
 *

…255 more lines…

Registry JSON

The raw registry record — what the shadcn CLI fetches.

/r/use-theme.json