Officialvercel-labs/agent-skillsMIT9 files

Vercel React View Transitions

Guide for implementing smooth, native-feeling animations using React's View Transition API (`<ViewTransition>` component, `addTransitionType`, and CSS view transition pseudo-elements). Use this skill whenever the user wants to add page transitions, animate route changes, create shared element animations, animate enter/exit of components, animate list reorder, implement directional (forward/back) navigation animations, or integrate view transitions in Next.js. Also use when the user mentions view transitions, `startViewTransition`, `ViewTransition`, transition types, or asks about animating between UI states in React without third-party animation libraries.

Specification
Skill ID
vercel-labs/agent-skills/vercel-react-view-transitions
Publisher
vercel-labs
Repository
agent-skills
Installs
1,280
Files
9
License
MIT
Synced
Sep 16, 2026
How to use it

Open any RiverX project, open the Skills panel in the chat, and search for this identifier. The files are fetched from the source repository at install time.

vercel-labs/agent-skills/vercel-react-view-transitionsInstalls these files
  • AGENTS.md
  • README.md
  • SKILL.md
  • metadata.json
  • references/css-recipes.md
  • references/implementation.md
  • references/nextjs.md
  • references/patterns.md
  • references/troubleshooting.md

What this skill tells the agent

React View Transitions

Animate between UI states using the browser's native document.startViewTransition. Declare what with <ViewTransition>, trigger when with startTransition / useDeferredValue / Suspense, control how with CSS classes. Unsupported browsers skip animations gracefully.

When to Animate

Every <ViewTransition> should communicate a spatial relationship or continuity. If you can't articulate what it communicates, don't add it.

Implement all applicable patterns from this list, in this order:

PriorityPatternWhat it communicates
1Shared element (name)"Same thing — going deeper"
2Suspense reveal"Data loaded"
3List identity (per-item key)"Same items, new arrangement"
4State change (enter/exit)"Something appeared/disappeared"
5Route change (page-level)"Going to a new place"

This is an implementation order, not a "pick one" list. Implement every pattern that fits the app. Only skip a pattern if the app has no use case for it.

Choosing Animation Style

ContextAnimationWhy
Hierarchical navigation (list → detail)Type-keyed nav-forward / nav-backCommunicates spatial depth
Lateral navigation (tab-to-tab)Bare <ViewTransition> (fade) or default="none"No depth to communicate
Suspense revealenter/exit string propsContent arriving
Revalidation / background refreshdefault="none"Silent — no animation needed

Reserve directional slides for hierarchical navigation (list → detail) and ordered sequences (prev/next photo, carousel, paginated results). For ordered sequences, the direction communicates position: "next" slides from right, "previous" from left. Lateral/unordered navigation (tab-to-tab) should not use directional slides — it falsely implies spatial depth.


Availability

  • Next.js: Do not install react@canary — the App Router already bundles React canary internally. ViewTransition works out of the box. npm ls react may show a stable-looking version; this is expected.
  • Without Next.js: Install react@canary react-dom@canary (ViewTransition is not in stable React).
  • Browser support: Chromium 125+ (React needs the v2 object form of startViewTransition), Firefox 144+, Safari 18.2+. Graceful degradation on unsupported browsers.

Implementation Workflow

When adding view transitions to an existing app, follow [references/implementation.md](references/implementation.md) step by step. Start with the audit — do not skip it. Use references/css-recipes.md for the applicable CSS and adapt it to the app.


Core Concepts

The <ViewTransition> Component

import { ViewTransition } from 'react';

<ViewTransition>
  <Component />
</ViewTransition>

React auto-assigns a unique view-transition-name and calls document.startViewTransition behind the scenes. Never call startViewTransition yourself.

Animation Triggers

TriggerWhen it fires
enter<ViewTransition> first inserted during a Transition
exit<ViewTransition> first removed during a Transition
updateDOM mutations inside a <ViewTransition>, or the boundary itself changing size/position due to an immediate sibling. With nested VTs, mutation applies to the innermost one
shareNamed VT unmounts and another with same name mounts in the same Transition

Only startTransition, useDeferredValue, or Suspense activate VTs. Regular setState does not animate.

Critical Placement Rule

<ViewTransition> only activates enter/exit if it appears before any DOM nodes:

// Works
<ViewTransition enter="auto" exit="auto">
  <div>Content</div>
</ViewTransition>

// Broken — div wraps the VT, suppressing enter/exit
<div>
  <ViewTransition enter="auto" exit="auto">
    <div>Content</div>
  </ViewTransition>
</div>

Styling with View Transition Classes

Props

Values: "auto" (browser cross-fade), "none" (disabled), "class-name" (custom CSS), or { [type]: value } for type-specific animations.

<ViewTransition default="none" enter="slide-in" exit="slide-out" share="morph" />

If default is "none", all triggers are off unless explicitly listed.

CSS Pseudo-Elements

  • ::view-transition-old(.class) — outgoing snapshot
  • ::view-transition-new(.class) — incoming snapshot
  • ::view-transition-group(.class) — container
  • ::view-transition-image-pair(.class) — old + new pair

See references/css-recipes.md for ready-to-use animation recipes.


Transition Types

Tag transitions with addTransitionType so VTs can pick different animations based on context. Call it multiple times to stack types — different VTs in the tree react to different types:

startTransition(() => {
  addTransitionType('nav-forward');
  addTransitionType('select-item');
  router.push('/detail/1');
});

Pass an object to map types to CSS classes. Works on enter, exit, and share:

<ViewTransition
  enter={{ 'nav-forward': 'slide-from-right', 'nav-back': 'slide-from-left', default: 'none' }}
  exit={{ 'nav-forward': 'slide-to-left', 'nav-back': 'slide-to-right', default: 'none' }}
  share={{ 'nav-forward': 'morph-forward', 'nav-back': 'morph-back', default: 'morph' }}
  default="none"
>
  <Page />
</ViewTransition>

enter and exit don't have to be symmetric. For example, fade in but slide out directionally:

<ViewTransition
  enter={{ 'nav-forward': 'fade-in', 'nav-back': 'fade-in', default: 'none' }}
  exit={{ 'nav-forward': 'nav-forward', 'nav-back': 'nav-back', default: 'none' }}
  default="none"
>

TypeScript: ViewTransitionClassPerType requires a default key in the object.

For apps with multiple pages, extract the type-keyed VT into a reusable wrapper:

export function DirectionalTransition({ children }: { children: React.ReactNode }) {
  return (
    <ViewTransition
      enter={{ 'nav-forward': 'nav-forward', 'nav-back': 'nav-back', default: 'none' }}
      exit={{ 'nav-forward': 'nav-forward', 'nav-back': 'nav-back', default: 'none' }}
      default="none"
    >
      {children}
    </ViewTransition>
  );
}

router.back() and Browser Back Button

router.back() and the browser's back/forward buttons carry no transition types, so type-keyed animations (directional slides) resolve to their default and don't play — untyped shared-element morphs still apply. For typed animations, use router.push() with an explicit URL.

Types and Suspense

Types are available during navigation but not during subsequent Suspense reveals (separate transitions, no type). Use type maps for page-level enter/exit; use simple string props for Suspense reveals.

Shared Element Readiness

A shared element transition can pair elements only when both the old and new views are rendered in the same Transition. If incoming content suspends, only its fallback exists for that update; the resolved content appears in a later Suspense transition and can be animated separately.


Shared Element Transitions

Same name on two VTs — one unmounting, one mounting — creates a shared element morph:

<ViewTransition name="hero-image">
  <img src="/thumb.jpg" onClick={() => startTransition(() => onSelect())} />
</ViewTransition>

// On the other view — same name
<ViewTransition name="hero-image">
  <img src="/full.jpg" />
</ViewTransition>