Border Beam

A single gradient square that travels around the inside edge of its parent, drawn with `offset-path` and a two-layer CSS mask so only the border ring shows. Drop it inside any `relative`, rounded container to give that container a moving outline.

decorativeclientuiv1.1.0

Border Beam — live rendermagicui-borderbeam--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/border-beam.json

With the @interlace alias

npx shadcn@latest add @interlace/border-beam

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.

@interlace/ui 1.1.01 entry

Changedpatch
Six defects found by upgrading a real consumer, plus five found by reading the components closely enough to document them. **Meteors' glow never painted.** It read var(--color-meteor-glow) while its cssVars declare --meteor-glow; --color-* is the Tailwind @theme namespace and only cssVars.theme populates it, so the whole box-shadow was invalid at computed-value time. **This was broken only for registry consumers** — our own docs site hand-declares the --color- form. **ArticleCard cropped 28% off every cover.** h-44 is 176px; at a ~302px tile that is a 1.72:1 box against a 2.381:1 image. Now aspect-[1000/420] — the ratio the card already declared on its <img>. It also gains a renderImage slot, because every Next.js consumer was re-patching the same line to use next/image and the design system cannot depend on it. **BorderBeam and StarsBackground had no aria-hidden at all** — six purely decorative nodes a screen reader walked. **CloudParticles defaulted bodyColor to currentColor**, painting volumetric clouds in the inherited text colour. **NumberTicker gains notation**, because six-figure metrics overflow a tile at 320px. Also: SheetCompose and DialogCompose each mounted a second backdrop, so a composed dialog dimmed the page twice as much as the hand-composed tree the docs show; Accordion dropped className on the animated Panel; Tooltip accepted delay and discarded it; PopoverAnchor was a second trigger. **useReducedMotion was one frame late.** The canonical useState(false) plus effect returns false on the first render, so every gated component painted one frame of exactly the motion the user turned off. useSyncExternalStore reads during render and closes that on client renders; on hydration the server cannot know the preference, which is what the stylesheet reset is for. Badge drops 'use client' — verified with a real server-component build.
Components

Import

Single named export.

Public API

import { BorderBeam } from '@/components/ui/magicui/border-beam';

Anatomy

Extracted from the primitive's JSDoc header. The source is the only documentation that can't drift.

div                              (absolute inset-0, rounded-[inherit],
                                    transparent border + mask-intersect —
                                    this is what clips the beam to the ring)
    └─ div.animate-border-beam     (the beam: an aspect-square gradient
                                    riding `offset-path: rect(… round Npx)`)

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: Animation is gated on prefers-reduced-motion.
ARIA in the source: aria-hidden

Examples

3 more states from the same story file.

reversemagicui-borderbeam--reverse ↗

thick and slowmagicui-borderbeam--thick-and-slow ↗

brand gradientmagicui-borderbeam--brand-gradient ↗

Dependencies

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

Source

The full implementation — components/ui/magicui/border-beam.tsx once installed.

174 lines · TypeScript

github ↗

"use client"

import { cn } from "@/lib/utils"



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

/**
 * @interlace/ui — BorderBeam
 *
 * A single gradient square that travels around the inside edge of its parent,
 * drawn with `offset-path` and a two-layer CSS mask so only the border ring
 * shows. Drop it inside any `relative`, rounded container to give that
 * container a moving outline.
 *
 * It positions itself `absolute inset-0` and inherits the parent's radius, so

…154 more lines…

Registry JSON

The raw registry record — what the shadcn CLI fetches.

/r/border-beam.json