` and animate the wrapper instead.
-
-**Incorrect (animating SVG directly - no hardware acceleration):**
-
-```tsx
-function LoadingSpinner() {
- return (
-
-
- )
-}
-```
-
-**Correct (animating wrapper div - hardware accelerated):**
-
-```tsx
-function LoadingSpinner() {
- return (
-
-
-
-
- )
-}
-```
-
-This applies to all CSS transforms and transitions (`transform`, `opacity`, `translate`, `scale`, `rotate`). The wrapper div allows browsers to use GPU acceleration for smoother animations.
diff --git a/.claude/skills/vercel-react-best-practices/rules/rendering-conditional-render.md b/.claude/skills/vercel-react-best-practices/rules/rendering-conditional-render.md
deleted file mode 100644
index 7e866f58..00000000
--- a/.claude/skills/vercel-react-best-practices/rules/rendering-conditional-render.md
+++ /dev/null
@@ -1,40 +0,0 @@
----
-title: Use Explicit Conditional Rendering
-impact: LOW
-impactDescription: prevents rendering 0 or NaN
-tags: rendering, conditional, jsx, falsy-values
----
-
-## Use Explicit Conditional Rendering
-
-Use explicit ternary operators (`? :`) instead of `&&` for conditional rendering when the condition can be `0`, `NaN`, or other falsy values that render.
-
-**Incorrect (renders "0" when count is 0):**
-
-```tsx
-function Badge({ count }: { count: number }) {
- return (
-
- {count && {count} }
-
- )
-}
-
-// When count = 0, renders:
0
-// When count = 5, renders:
5
-```
-
-**Correct (renders nothing when count is 0):**
-
-```tsx
-function Badge({ count }: { count: number }) {
- return (
-
- {count > 0 ? {count} : null}
-
- )
-}
-
-// When count = 0, renders:
-// When count = 5, renders:
5
-```
diff --git a/.claude/skills/vercel-react-best-practices/rules/rendering-content-visibility.md b/.claude/skills/vercel-react-best-practices/rules/rendering-content-visibility.md
deleted file mode 100644
index aa665636..00000000
--- a/.claude/skills/vercel-react-best-practices/rules/rendering-content-visibility.md
+++ /dev/null
@@ -1,38 +0,0 @@
----
-title: CSS content-visibility for Long Lists
-impact: HIGH
-impactDescription: faster initial render
-tags: rendering, css, content-visibility, long-lists
----
-
-## CSS content-visibility for Long Lists
-
-Apply `content-visibility: auto` to defer off-screen rendering.
-
-**CSS:**
-
-```css
-.message-item {
- content-visibility: auto;
- contain-intrinsic-size: 0 80px;
-}
-```
-
-**Example:**
-
-```tsx
-function MessageList({ messages }: { messages: Message[] }) {
- return (
-
- {messages.map(msg => (
-
- ))}
-
- )
-}
-```
-
-For 1000 messages, browser skips layout/paint for ~990 off-screen items (10× faster initial render).
diff --git a/.claude/skills/vercel-react-best-practices/rules/rendering-hoist-jsx.md b/.claude/skills/vercel-react-best-practices/rules/rendering-hoist-jsx.md
deleted file mode 100644
index 32d2f3fc..00000000
--- a/.claude/skills/vercel-react-best-practices/rules/rendering-hoist-jsx.md
+++ /dev/null
@@ -1,46 +0,0 @@
----
-title: Hoist Static JSX Elements
-impact: LOW
-impactDescription: avoids re-creation
-tags: rendering, jsx, static, optimization
----
-
-## Hoist Static JSX Elements
-
-Extract static JSX outside components to avoid re-creation.
-
-**Incorrect (recreates element every render):**
-
-```tsx
-function LoadingSkeleton() {
- return
-}
-
-function Container() {
- return (
-
- {loading &&
- )
-}
-```
-
-**Correct (reuses same element):**
-
-```tsx
-const loadingSkeleton = (
-
-)
-
-function Container() {
- return (
-
- {loading && loadingSkeleton}
-
- )
-}
-```
-
-This is especially helpful for large and static SVG nodes, which can be expensive to recreate on every render.
-
-**Note:** If your project has [React Compiler](https://react.dev/learn/react-compiler) enabled, the compiler automatically hoists static JSX elements and optimizes component re-renders, making manual hoisting unnecessary.
diff --git a/.claude/skills/vercel-react-best-practices/rules/rendering-hydration-no-flicker.md b/.claude/skills/vercel-react-best-practices/rules/rendering-hydration-no-flicker.md
deleted file mode 100644
index 5cf0e79b..00000000
--- a/.claude/skills/vercel-react-best-practices/rules/rendering-hydration-no-flicker.md
+++ /dev/null
@@ -1,82 +0,0 @@
----
-title: Prevent Hydration Mismatch Without Flickering
-impact: MEDIUM
-impactDescription: avoids visual flicker and hydration errors
-tags: rendering, ssr, hydration, localStorage, flicker
----
-
-## Prevent Hydration Mismatch Without Flickering
-
-When rendering content that depends on client-side storage (localStorage, cookies), avoid both SSR breakage and post-hydration flickering by injecting a synchronous script that updates the DOM before React hydrates.
-
-**Incorrect (breaks SSR):**
-
-```tsx
-function ThemeWrapper({ children }: { children: ReactNode }) {
- // localStorage is not available on server - throws error
- const theme = localStorage.getItem('theme') || 'light'
-
- return (
-
- {children}
-
- )
-}
-```
-
-Server-side rendering will fail because `localStorage` is undefined.
-
-**Incorrect (visual flickering):**
-
-```tsx
-function ThemeWrapper({ children }: { children: ReactNode }) {
- const [theme, setTheme] = useState('light')
-
- useEffect(() => {
- // Runs after hydration - causes visible flash
- const stored = localStorage.getItem('theme')
- if (stored) {
- setTheme(stored)
- }
- }, [])
-
- return (
-
- {children}
-
- )
-}
-```
-
-Component first renders with default value (`light`), then updates after hydration, causing a visible flash of incorrect content.
-
-**Correct (no flicker, no hydration mismatch):**
-
-```tsx
-function ThemeWrapper({ children }: { children: ReactNode }) {
- return (
- <>
-
- {children}
-
-
-
- )
-}
-```
-
-The inline script executes synchronously before showing the element, ensuring the DOM already has the correct value. No flickering, no hydration mismatch.
-
-This pattern is especially useful for theme toggles, user preferences, authentication states, and any client-only data that should render immediately without flashing default values.
diff --git a/.claude/skills/vercel-react-best-practices/rules/rendering-svg-precision.md b/.claude/skills/vercel-react-best-practices/rules/rendering-svg-precision.md
deleted file mode 100644
index 6d771286..00000000
--- a/.claude/skills/vercel-react-best-practices/rules/rendering-svg-precision.md
+++ /dev/null
@@ -1,28 +0,0 @@
----
-title: Optimize SVG Precision
-impact: LOW
-impactDescription: reduces file size
-tags: rendering, svg, optimization, svgo
----
-
-## Optimize SVG Precision
-
-Reduce SVG coordinate precision to decrease file size. The optimal precision depends on the viewBox size, but in general reducing precision should be considered.
-
-**Incorrect (excessive precision):**
-
-```svg
-
-```
-
-**Correct (1 decimal place):**
-
-```svg
-
-```
-
-**Automate with SVGO:**
-
-```bash
-npx svgo --precision=1 --multipass icon.svg
-```
diff --git a/.claude/skills/vercel-react-best-practices/rules/rerender-defer-reads.md b/.claude/skills/vercel-react-best-practices/rules/rerender-defer-reads.md
deleted file mode 100644
index e867c95f..00000000
--- a/.claude/skills/vercel-react-best-practices/rules/rerender-defer-reads.md
+++ /dev/null
@@ -1,39 +0,0 @@
----
-title: Defer State Reads to Usage Point
-impact: MEDIUM
-impactDescription: avoids unnecessary subscriptions
-tags: rerender, searchParams, localStorage, optimization
----
-
-## Defer State Reads to Usage Point
-
-Don't subscribe to dynamic state (searchParams, localStorage) if you only read it inside callbacks.
-
-**Incorrect (subscribes to all searchParams changes):**
-
-```tsx
-function ShareButton({ chatId }: { chatId: string }) {
- const searchParams = useSearchParams()
-
- const handleShare = () => {
- const ref = searchParams.get('ref')
- shareChat(chatId, { ref })
- }
-
- return
Share
-}
-```
-
-**Correct (reads on demand, no subscription):**
-
-```tsx
-function ShareButton({ chatId }: { chatId: string }) {
- const handleShare = () => {
- const params = new URLSearchParams(window.location.search)
- const ref = params.get('ref')
- shareChat(chatId, { ref })
- }
-
- return
Share
-}
-```
diff --git a/.claude/skills/vercel-react-best-practices/rules/rerender-dependencies.md b/.claude/skills/vercel-react-best-practices/rules/rerender-dependencies.md
deleted file mode 100644
index 47a4d926..00000000
--- a/.claude/skills/vercel-react-best-practices/rules/rerender-dependencies.md
+++ /dev/null
@@ -1,45 +0,0 @@
----
-title: Narrow Effect Dependencies
-impact: LOW
-impactDescription: minimizes effect re-runs
-tags: rerender, useEffect, dependencies, optimization
----
-
-## Narrow Effect Dependencies
-
-Specify primitive dependencies instead of objects to minimize effect re-runs.
-
-**Incorrect (re-runs on any user field change):**
-
-```tsx
-useEffect(() => {
- console.log(user.id)
-}, [user])
-```
-
-**Correct (re-runs only when id changes):**
-
-```tsx
-useEffect(() => {
- console.log(user.id)
-}, [user.id])
-```
-
-**For derived state, compute outside effect:**
-
-```tsx
-// Incorrect: runs on width=767, 766, 765...
-useEffect(() => {
- if (width < 768) {
- enableMobileMode()
- }
-}, [width])
-
-// Correct: runs only on boolean transition
-const isMobile = width < 768
-useEffect(() => {
- if (isMobile) {
- enableMobileMode()
- }
-}, [isMobile])
-```
diff --git a/.claude/skills/vercel-react-best-practices/rules/rerender-derived-state.md b/.claude/skills/vercel-react-best-practices/rules/rerender-derived-state.md
deleted file mode 100644
index a15177ca..00000000
--- a/.claude/skills/vercel-react-best-practices/rules/rerender-derived-state.md
+++ /dev/null
@@ -1,29 +0,0 @@
----
-title: Subscribe to Derived State
-impact: MEDIUM
-impactDescription: reduces re-render frequency
-tags: rerender, derived-state, media-query, optimization
----
-
-## Subscribe to Derived State
-
-Subscribe to derived boolean state instead of continuous values to reduce re-render frequency.
-
-**Incorrect (re-renders on every pixel change):**
-
-```tsx
-function Sidebar() {
- const width = useWindowWidth() // updates continuously
- const isMobile = width < 768
- return
-}
-```
-
-**Correct (re-renders only when boolean changes):**
-
-```tsx
-function Sidebar() {
- const isMobile = useMediaQuery('(max-width: 767px)')
- return
-}
-```
diff --git a/.claude/skills/vercel-react-best-practices/rules/rerender-functional-setstate.md b/.claude/skills/vercel-react-best-practices/rules/rerender-functional-setstate.md
deleted file mode 100644
index b004ef45..00000000
--- a/.claude/skills/vercel-react-best-practices/rules/rerender-functional-setstate.md
+++ /dev/null
@@ -1,74 +0,0 @@
----
-title: Use Functional setState Updates
-impact: MEDIUM
-impactDescription: prevents stale closures and unnecessary callback recreations
-tags: react, hooks, useState, useCallback, callbacks, closures
----
-
-## Use Functional setState Updates
-
-When updating state based on the current state value, use the functional update form of setState instead of directly referencing the state variable. This prevents stale closures, eliminates unnecessary dependencies, and creates stable callback references.
-
-**Incorrect (requires state as dependency):**
-
-```tsx
-function TodoList() {
- const [items, setItems] = useState(initialItems)
-
- // Callback must depend on items, recreated on every items change
- const addItems = useCallback((newItems: Item[]) => {
- setItems([...items, ...newItems])
- }, [items]) // ❌ items dependency causes recreations
-
- // Risk of stale closure if dependency is forgotten
- const removeItem = useCallback((id: string) => {
- setItems(items.filter(item => item.id !== id))
- }, []) // ❌ Missing items dependency - will use stale items!
-
- return {avatar}
-}
-```
-
-**Correct (skips computation when loading):**
-
-```tsx
-const UserAvatar = memo(function UserAvatar({ user }: { user: User }) {
- const id = useMemo(() => computeAvatarId(user), [user])
- return
-
- )
-}
-```
-
-**Note:** If your project has [React Compiler](https://react.dev/learn/react-compiler) enabled, manual memoization with `memo()` and `useMemo()` is not necessary. The compiler automatically optimizes re-renders.
diff --git a/.claude/skills/vercel-react-best-practices/rules/rerender-transitions.md b/.claude/skills/vercel-react-best-practices/rules/rerender-transitions.md
deleted file mode 100644
index d99f43f7..00000000
--- a/.claude/skills/vercel-react-best-practices/rules/rerender-transitions.md
+++ /dev/null
@@ -1,40 +0,0 @@
----
-title: Use Transitions for Non-Urgent Updates
-impact: MEDIUM
-impactDescription: maintains UI responsiveness
-tags: rerender, transitions, startTransition, performance
----
-
-## Use Transitions for Non-Urgent Updates
-
-Mark frequent, non-urgent state updates as transitions to maintain UI responsiveness.
-
-**Incorrect (blocks UI on every scroll):**
-
-```tsx
-function ScrollTracker() {
- const [scrollY, setScrollY] = useState(0)
- useEffect(() => {
- const handler = () => setScrollY(window.scrollY)
- window.addEventListener('scroll', handler, { passive: true })
- return () => window.removeEventListener('scroll', handler)
- }, [])
-}
-```
-
-**Correct (non-blocking updates):**
-
-```tsx
-import { startTransition } from 'react'
-
-function ScrollTracker() {
- const [scrollY, setScrollY] = useState(0)
- useEffect(() => {
- const handler = () => {
- startTransition(() => setScrollY(window.scrollY))
- }
- window.addEventListener('scroll', handler, { passive: true })
- return () => window.removeEventListener('scroll', handler)
- }, [])
-}
-```
diff --git a/.claude/skills/vercel-react-best-practices/rules/server-after-nonblocking.md b/.claude/skills/vercel-react-best-practices/rules/server-after-nonblocking.md
deleted file mode 100644
index e8f5b260..00000000
--- a/.claude/skills/vercel-react-best-practices/rules/server-after-nonblocking.md
+++ /dev/null
@@ -1,73 +0,0 @@
----
-title: Use after() for Non-Blocking Operations
-impact: MEDIUM
-impactDescription: faster response times
-tags: server, async, logging, analytics, side-effects
----
-
-## Use after() for Non-Blocking Operations
-
-Use Next.js's `after()` to schedule work that should execute after a response is sent. This prevents logging, analytics, and other side effects from blocking the response.
-
-**Incorrect (blocks response):**
-
-```tsx
-import { logUserAction } from '@/app/utils'
-
-export async function POST(request: Request) {
- // Perform mutation
- await updateDatabase(request)
-
- // Logging blocks the response
- const userAgent = request.headers.get('user-agent') || 'unknown'
- await logUserAction({ userAgent })
-
- return new Response(JSON.stringify({ status: 'success' }), {
- status: 200,
- headers: { 'Content-Type': 'application/json' }
- })
-}
-```
-
-**Correct (non-blocking):**
-
-```tsx
-import { after } from 'next/server'
-import { headers, cookies } from 'next/headers'
-import { logUserAction } from '@/app/utils'
-
-export async function POST(request: Request) {
- // Perform mutation
- await updateDatabase(request)
-
- // Log after response is sent
- after(async () => {
- const userAgent = (await headers()).get('user-agent') || 'unknown'
- const sessionCookie = (await cookies()).get('session-id')?.value || 'anonymous'
-
- logUserAction({ sessionCookie, userAgent })
- })
-
- return new Response(JSON.stringify({ status: 'success' }), {
- status: 200,
- headers: { 'Content-Type': 'application/json' }
- })
-}
-```
-
-The response is sent immediately while logging happens in the background.
-
-**Common use cases:**
-
-- Analytics tracking
-- Audit logging
-- Sending notifications
-- Cache invalidation
-- Cleanup tasks
-
-**Important notes:**
-
-- `after()` runs even if the response fails or redirects
-- Works in Server Actions, Route Handlers, and Server Components
-
-Reference: [https://nextjs.org/docs/app/api-reference/functions/after](https://nextjs.org/docs/app/api-reference/functions/after)
diff --git a/.claude/skills/vercel-react-best-practices/rules/server-cache-lru.md b/.claude/skills/vercel-react-best-practices/rules/server-cache-lru.md
deleted file mode 100644
index ef6938aa..00000000
--- a/.claude/skills/vercel-react-best-practices/rules/server-cache-lru.md
+++ /dev/null
@@ -1,41 +0,0 @@
----
-title: Cross-Request LRU Caching
-impact: HIGH
-impactDescription: caches across requests
-tags: server, cache, lru, cross-request
----
-
-## Cross-Request LRU Caching
-
-`React.cache()` only works within one request. For data shared across sequential requests (user clicks button A then button B), use an LRU cache.
-
-**Implementation:**
-
-```typescript
-import { LRUCache } from 'lru-cache'
-
-const cache = new LRUCache({
- max: 1000,
- ttl: 5 * 60 * 1000 // 5 minutes
-})
-
-export async function getUser(id: string) {
- const cached = cache.get(id)
- if (cached) return cached
-
- const user = await db.user.findUnique({ where: { id } })
- cache.set(id, user)
- return user
-}
-
-// Request 1: DB query, result cached
-// Request 2: cache hit, no DB query
-```
-
-Use when sequential user actions hit multiple endpoints needing the same data within seconds.
-
-**With Vercel's [Fluid Compute](https://vercel.com/docs/fluid-compute):** LRU caching is especially effective because multiple concurrent requests can share the same function instance and cache. This means the cache persists across requests without needing external storage like Redis.
-
-**In traditional serverless:** Each invocation runs in isolation, so consider Redis for cross-process caching.
-
-Reference: [https://github.com/isaacs/node-lru-cache](https://github.com/isaacs/node-lru-cache)
diff --git a/.claude/skills/vercel-react-best-practices/rules/server-cache-react.md b/.claude/skills/vercel-react-best-practices/rules/server-cache-react.md
deleted file mode 100644
index fa49e0e8..00000000
--- a/.claude/skills/vercel-react-best-practices/rules/server-cache-react.md
+++ /dev/null
@@ -1,26 +0,0 @@
----
-title: Per-Request Deduplication with React.cache()
-impact: MEDIUM
-impactDescription: deduplicates within request
-tags: server, cache, react-cache, deduplication
----
-
-## Per-Request Deduplication with React.cache()
-
-Use `React.cache()` for server-side request deduplication. Authentication and database queries benefit most.
-
-**Usage:**
-
-```typescript
-import { cache } from 'react'
-
-export const getCurrentUser = cache(async () => {
- const session = await auth()
- if (!session?.user?.id) return null
- return await db.user.findUnique({
- where: { id: session.user.id }
- })
-})
-```
-
-Within a single request, multiple calls to `getCurrentUser()` execute the query only once.
diff --git a/.claude/skills/vercel-react-best-practices/rules/server-parallel-fetching.md b/.claude/skills/vercel-react-best-practices/rules/server-parallel-fetching.md
deleted file mode 100644
index 5261f084..00000000
--- a/.claude/skills/vercel-react-best-practices/rules/server-parallel-fetching.md
+++ /dev/null
@@ -1,79 +0,0 @@
----
-title: Parallel Data Fetching with Component Composition
-impact: CRITICAL
-impactDescription: eliminates server-side waterfalls
-tags: server, rsc, parallel-fetching, composition
----
-
-## Parallel Data Fetching with Component Composition
-
-React Server Components execute sequentially within a tree. Restructure with composition to parallelize data fetching.
-
-**Incorrect (Sidebar waits for Page's fetch to complete):**
-
-```tsx
-export default async function Page() {
- const header = await fetchHeader()
- return (
-
- )
-}
-
-async function Sidebar() {
- const items = await fetchSidebarItems()
- return {items.map(renderItem)}
-}
-```
-
-**Correct (both fetch simultaneously):**
-
-```tsx
-async function Header() {
- const data = await fetchHeader()
- return {data}
-}
-
-async function Sidebar() {
- const items = await fetchSidebarItems()
- return {items.map(renderItem)}
-}
-
-export default function Page() {
- return (
-
-
-
- )
-}
-```
-
-**Alternative with children prop:**
-
-```tsx
-async function Layout({ children }: { children: ReactNode }) {
- const header = await fetchHeader()
- return (
-
-
{header}
- {children}
-
{items.map(renderItem)}
-}
-
-export default function Page() {
- return (
-
-
- )
-}
-```
diff --git a/.claude/skills/vercel-react-best-practices/rules/server-serialization.md b/.claude/skills/vercel-react-best-practices/rules/server-serialization.md
deleted file mode 100644
index 39c5c416..00000000
--- a/.claude/skills/vercel-react-best-practices/rules/server-serialization.md
+++ /dev/null
@@ -1,38 +0,0 @@
----
-title: Minimize Serialization at RSC Boundaries
-impact: HIGH
-impactDescription: reduces data transfer size
-tags: server, rsc, serialization, props
----
-
-## Minimize Serialization at RSC Boundaries
-
-The React Server/Client boundary serializes all object properties into strings and embeds them in the HTML response and subsequent RSC requests. This serialized data directly impacts page weight and load time, so **size matters a lot**. Only pass fields that the client actually uses.
-
-**Incorrect (serializes all 50 fields):**
-
-```tsx
-async function Page() {
- const user = await fetchUser() // 50 fields
- return {user.name}
// uses 1 field
-}
-```
-
-**Correct (serializes only 1 field):**
-
-```tsx
-async function Page() {
- const user = await fetchUser()
- return {name}
-}
-```
diff --git a/.claude/skills/web-design-guidelines/SKILL.md b/.claude/skills/web-design-guidelines/SKILL.md
deleted file mode 100644
index 83b34c20..00000000
--- a/.claude/skills/web-design-guidelines/SKILL.md
+++ /dev/null
@@ -1,36 +0,0 @@
----
-name: web-design-guidelines
-description: Review UI code for Web Interface Guidelines compliance. Use when asked to "review my UI", "check accessibility", "audit design", "review UX", or "check my site against best practices".
-argument-hint:
----
-
-# Web Interface Guidelines
-
-Review files for compliance with Web Interface Guidelines.
-
-## How It Works
-
-1. Fetch the latest guidelines from the source URL below
-2. Read the specified files (or prompt user for files/pattern)
-3. Check against all rules in the fetched guidelines
-4. Output findings in the terse `file:line` format
-
-## Guidelines Source
-
-Fetch fresh guidelines before each review:
-
-```
-https://raw.githubusercontent.com/vercel-labs/web-interface-guidelines/main/command.md
-```
-
-Use WebFetch to retrieve the latest rules. The fetched content contains all the rules and output format instructions.
-
-## Usage
-
-When a user provides a file or pattern argument:
-1. Fetch guidelines from the source URL above
-2. Read the specified files
-3. Apply all rules from the fetched guidelines
-4. Output findings using the format specified in the guidelines
-
-If no files specified, ask the user which files to review.
diff --git a/.github/skills/vercel-react-best-practices/AGENTS.md b/.github/skills/vercel-react-best-practices/AGENTS.md
deleted file mode 100644
index 898afb39..00000000
--- a/.github/skills/vercel-react-best-practices/AGENTS.md
+++ /dev/null
@@ -1,2249 +0,0 @@
-# React Best Practices
-
-**Version 0.1.0**
-Vercel Engineering
-January 2026
-
-> **Note:**
-> This document is mainly for agents and LLMs to follow when maintaining,
-> generating, or refactoring React and Next.js codebases at Vercel. Humans
-> may also find it useful, but guidance here is optimized for automation
-> and consistency by AI-assisted workflows.
-
----
-
-## Abstract
-
-Comprehensive performance optimization guide for React and Next.js applications, designed for AI agents and LLMs. Contains 40+ rules across 8 categories, prioritized by impact from critical (eliminating waterfalls, reducing bundle size) to incremental (advanced patterns). Each rule includes detailed explanations, real-world examples comparing incorrect vs. correct implementations, and specific impact metrics to guide automated refactoring and code generation.
-
----
-
-## Table of Contents
-
-1. [Eliminating Waterfalls](#1-eliminating-waterfalls) — **CRITICAL**
- - 1.1 [Defer Await Until Needed](#11-defer-await-until-needed)
- - 1.2 [Dependency-Based Parallelization](#12-dependency-based-parallelization)
- - 1.3 [Prevent Waterfall Chains in API Routes](#13-prevent-waterfall-chains-in-api-routes)
- - 1.4 [Promise.all() for Independent Operations](#14-promiseall-for-independent-operations)
- - 1.5 [Strategic Suspense Boundaries](#15-strategic-suspense-boundaries)
-2. [Bundle Size Optimization](#2-bundle-size-optimization) — **CRITICAL**
- - 2.1 [Avoid Barrel File Imports](#21-avoid-barrel-file-imports)
- - 2.2 [Conditional Module Loading](#22-conditional-module-loading)
- - 2.3 [Defer Non-Critical Third-Party Libraries](#23-defer-non-critical-third-party-libraries)
- - 2.4 [Dynamic Imports for Heavy Components](#24-dynamic-imports-for-heavy-components)
- - 2.5 [Preload Based on User Intent](#25-preload-based-on-user-intent)
-3. [Server-Side Performance](#3-server-side-performance) — **HIGH**
- - 3.1 [Cross-Request LRU Caching](#31-cross-request-lru-caching)
- - 3.2 [Minimize Serialization at RSC Boundaries](#32-minimize-serialization-at-rsc-boundaries)
- - 3.3 [Parallel Data Fetching with Component Composition](#33-parallel-data-fetching-with-component-composition)
- - 3.4 [Per-Request Deduplication with React.cache()](#34-per-request-deduplication-with-reactcache)
- - 3.5 [Use after() for Non-Blocking Operations](#35-use-after-for-non-blocking-operations)
-4. [Client-Side Data Fetching](#4-client-side-data-fetching) — **MEDIUM-HIGH**
- - 4.1 [Deduplicate Global Event Listeners](#41-deduplicate-global-event-listeners)
- - 4.2 [Use SWR for Automatic Deduplication](#42-use-swr-for-automatic-deduplication)
-5. [Re-render Optimization](#5-re-render-optimization) — **MEDIUM**
- - 5.1 [Defer State Reads to Usage Point](#51-defer-state-reads-to-usage-point)
- - 5.2 [Extract to Memoized Components](#52-extract-to-memoized-components)
- - 5.3 [Narrow Effect Dependencies](#53-narrow-effect-dependencies)
- - 5.4 [Subscribe to Derived State](#54-subscribe-to-derived-state)
- - 5.5 [Use Functional setState Updates](#55-use-functional-setstate-updates)
- - 5.6 [Use Lazy State Initialization](#56-use-lazy-state-initialization)
- - 5.7 [Use Transitions for Non-Urgent Updates](#57-use-transitions-for-non-urgent-updates)
-6. [Rendering Performance](#6-rendering-performance) — **MEDIUM**
- - 6.1 [Animate SVG Wrapper Instead of SVG Element](#61-animate-svg-wrapper-instead-of-svg-element)
- - 6.2 [CSS content-visibility for Long Lists](#62-css-content-visibility-for-long-lists)
- - 6.3 [Hoist Static JSX Elements](#63-hoist-static-jsx-elements)
- - 6.4 [Optimize SVG Precision](#64-optimize-svg-precision)
- - 6.5 [Prevent Hydration Mismatch Without Flickering](#65-prevent-hydration-mismatch-without-flickering)
- - 6.6 [Use Activity Component for Show/Hide](#66-use-activity-component-for-showhide)
- - 6.7 [Use Explicit Conditional Rendering](#67-use-explicit-conditional-rendering)
-7. [JavaScript Performance](#7-javascript-performance) — **LOW-MEDIUM**
- - 7.1 [Batch DOM CSS Changes](#71-batch-dom-css-changes)
- - 7.2 [Build Index Maps for Repeated Lookups](#72-build-index-maps-for-repeated-lookups)
- - 7.3 [Cache Property Access in Loops](#73-cache-property-access-in-loops)
- - 7.4 [Cache Repeated Function Calls](#74-cache-repeated-function-calls)
- - 7.5 [Cache Storage API Calls](#75-cache-storage-api-calls)
- - 7.6 [Combine Multiple Array Iterations](#76-combine-multiple-array-iterations)
- - 7.7 [Early Length Check for Array Comparisons](#77-early-length-check-for-array-comparisons)
- - 7.8 [Early Return from Functions](#78-early-return-from-functions)
- - 7.9 [Hoist RegExp Creation](#79-hoist-regexp-creation)
- - 7.10 [Use Loop for Min/Max Instead of Sort](#710-use-loop-for-minmax-instead-of-sort)
- - 7.11 [Use Set/Map for O(1) Lookups](#711-use-setmap-for-o1-lookups)
- - 7.12 [Use toSorted() Instead of sort() for Immutability](#712-use-tosorted-instead-of-sort-for-immutability)
-8. [Advanced Patterns](#8-advanced-patterns) — **LOW**
- - 8.1 [Store Event Handlers in Refs](#81-store-event-handlers-in-refs)
- - 8.2 [useLatest for Stable Callback Refs](#82-uselatest-for-stable-callback-refs)
-
----
-
-## 1. Eliminating Waterfalls
-
-**Impact: CRITICAL**
-
-Waterfalls are the #1 performance killer. Each sequential await adds full network latency. Eliminating them yields the largest gains.
-
-### 1.1 Defer Await Until Needed
-
-**Impact: HIGH (avoids blocking unused code paths)**
-
-Move `await` operations into the branches where they're actually used to avoid blocking code paths that don't need them.
-
-**Incorrect: blocks both branches**
-
-```typescript
-async function handleRequest(userId: string, skipProcessing: boolean) {
- const userData = await fetchUserData(userId)
-
- if (skipProcessing) {
- // Returns immediately but still waited for userData
- return { skipped: true }
- }
-
- // Only this branch uses userData
- return processUserData(userData)
-}
-```
-
-**Correct: only blocks when needed**
-
-```typescript
-async function handleRequest(userId: string, skipProcessing: boolean) {
- if (skipProcessing) {
- // Returns immediately without waiting
- return { skipped: true }
- }
-
- // Fetch only when needed
- const userData = await fetchUserData(userId)
- return processUserData(userData)
-}
-```
-
-**Another example: early return optimization**
-
-```typescript
-// Incorrect: always fetches permissions
-async function updateResource(resourceId: string, userId: string) {
- const permissions = await fetchPermissions(userId)
- const resource = await getResource(resourceId)
-
- if (!resource) {
- return { error: 'Not found' }
- }
-
- if (!permissions.canEdit) {
- return { error: 'Forbidden' }
- }
-
- return await updateResourceData(resource, permissions)
-}
-
-// Correct: fetches only when needed
-async function updateResource(resourceId: string, userId: string) {
- const resource = await getResource(resourceId)
-
- if (!resource) {
- return { error: 'Not found' }
- }
-
- const permissions = await fetchPermissions(userId)
-
- if (!permissions.canEdit) {
- return { error: 'Forbidden' }
- }
-
- return await updateResourceData(resource, permissions)
-}
-```
-
-This optimization is especially valuable when the skipped branch is frequently taken, or when the deferred operation is expensive.
-
-### 1.2 Dependency-Based Parallelization
-
-**Impact: CRITICAL (2-10× improvement)**
-
-For operations with partial dependencies, use `better-all` to maximize parallelism. It automatically starts each task at the earliest possible moment.
-
-**Incorrect: profile waits for config unnecessarily**
-
-```typescript
-const [user, config] = await Promise.all([
- fetchUser(),
- fetchConfig()
-])
-const profile = await fetchProfile(user.id)
-```
-
-**Correct: config and profile run in parallel**
-
-```typescript
-import { all } from 'better-all'
-
-const { user, config, profile } = await all({
- async user() { return fetchUser() },
- async config() { return fetchConfig() },
- async profile() {
- return fetchProfile((await this.$.user).id)
- }
-})
-```
-
-Reference: [https://github.com/shuding/better-all](https://github.com/shuding/better-all)
-
-### 1.3 Prevent Waterfall Chains in API Routes
-
-**Impact: CRITICAL (2-10× improvement)**
-
-In API routes and Server Actions, start independent operations immediately, even if you don't await them yet.
-
-**Incorrect: config waits for auth, data waits for both**
-
-```typescript
-export async function GET(request: Request) {
- const session = await auth()
- const config = await fetchConfig()
- const data = await fetchData(session.user.id)
- return Response.json({ data, config })
-}
-```
-
-**Correct: auth and config start immediately**
-
-```typescript
-export async function GET(request: Request) {
- const sessionPromise = auth()
- const configPromise = fetchConfig()
- const session = await sessionPromise
- const [config, data] = await Promise.all([
- configPromise,
- fetchData(session.user.id)
- ])
- return Response.json({ data, config })
-}
-```
-
-For operations with more complex dependency chains, use `better-all` to automatically maximize parallelism (see Dependency-Based Parallelization).
-
-### 1.4 Promise.all() for Independent Operations
-
-**Impact: CRITICAL (2-10× improvement)**
-
-When async operations have no interdependencies, execute them concurrently using `Promise.all()`.
-
-**Incorrect: sequential execution, 3 round trips**
-
-```typescript
-const user = await fetchUser()
-const posts = await fetchPosts()
-const comments = await fetchComments()
-```
-
-**Correct: parallel execution, 1 round trip**
-
-```typescript
-const [user, posts, comments] = await Promise.all([
- fetchUser(),
- fetchPosts(),
- fetchComments()
-])
-```
-
-### 1.5 Strategic Suspense Boundaries
-
-**Impact: HIGH (faster initial paint)**
-
-Instead of awaiting data in async components before returning JSX, use Suspense boundaries to show the wrapper UI faster while data loads.
-
-**Incorrect: wrapper blocked by data fetching**
-
-```tsx
-async function Page() {
- const data = await fetchData() // Blocks entire page
-
- return (
-
-
Sidebar
-
Header
-
-
-
Footer
-
-
Sidebar
-
Header
-
-
-
Footer
-
{data.content}
-}
-```
-
-Sidebar, Header, and Footer render immediately. Only DataDisplay waits for data.
-
-**Alternative: share promise across components**
-
-```tsx
-function Page() {
- // Start fetch immediately, but don't await
- const dataPromise = fetchData()
-
- return (
-
-
Sidebar
-
Header
-
}>
-
-
-
-
Footer
-
}) {
- const data = use(dataPromise) // Unwraps the promise
- return {data.content}
-}
-
-function DataSummary({ dataPromise }: { dataPromise: Promise }) {
- const data = use(dataPromise) // Reuses the same promise
- return {data.summary}
-}
-```
-
-Both components share the same promise, so only one fetch occurs. Layout renders immediately while both components wait together.
-
-**When NOT to use this pattern:**
-
-- Critical data needed for layout decisions (affects positioning)
-
-- SEO-critical content above the fold
-
-- Small, fast queries where suspense overhead isn't worth it
-
-- When you want to avoid layout shift (loading → content jump)
-
-**Trade-off:** Faster initial paint vs potential layout shift. Choose based on your UX priorities.
-
----
-
-## 2. Bundle Size Optimization
-
-**Impact: CRITICAL**
-
-Reducing initial bundle size improves Time to Interactive and Largest Contentful Paint.
-
-### 2.1 Avoid Barrel File Imports
-
-**Impact: CRITICAL (200-800ms import cost, slow builds)**
-
-Import directly from source files instead of barrel files to avoid loading thousands of unused modules. **Barrel files** are entry points that re-export multiple modules (e.g., `index.js` that does `export * from './module'`).
-
-Popular icon and component libraries can have **up to 10,000 re-exports** in their entry file. For many React packages, **it takes 200-800ms just to import them**, affecting both development speed and production cold starts.
-
-**Why tree-shaking doesn't help:** When a library is marked as external (not bundled), the bundler can't optimize it. If you bundle it to enable tree-shaking, builds become substantially slower analyzing the entire module graph.
-
-**Incorrect: imports entire library**
-
-```tsx
-import { Check, X, Menu } from 'lucide-react'
-// Loads 1,583 modules, takes ~2.8s extra in dev
-// Runtime cost: 200-800ms on every cold start
-
-import { Button, TextField } from '@mui/material'
-// Loads 2,225 modules, takes ~4.2s extra in dev
-```
-
-**Correct: imports only what you need**
-
-```tsx
-import Check from 'lucide-react/dist/esm/icons/check'
-import X from 'lucide-react/dist/esm/icons/x'
-import Menu from 'lucide-react/dist/esm/icons/menu'
-// Loads only 3 modules (~2KB vs ~1MB)
-
-import Button from '@mui/material/Button'
-import TextField from '@mui/material/TextField'
-// Loads only what you use
-```
-
-**Alternative: Next.js 13.5+**
-
-```js
-// next.config.js - use optimizePackageImports
-module.exports = {
- experimental: {
- optimizePackageImports: ['lucide-react', '@mui/material']
- }
-}
-
-// Then you can keep the ergonomic barrel imports:
-import { Check, X, Menu } from 'lucide-react'
-// Automatically transformed to direct imports at build time
-```
-
-Direct imports provide 15-70% faster dev boot, 28% faster builds, 40% faster cold starts, and significantly faster HMR.
-
-Libraries commonly affected: `lucide-react`, `@mui/material`, `@mui/icons-material`, `@tabler/icons-react`, `react-icons`, `@headlessui/react`, `@radix-ui/react-*`, `lodash`, `ramda`, `date-fns`, `rxjs`, `react-use`.
-
-Reference: [https://vercel.com/blog/how-we-optimized-package-imports-in-next-js](https://vercel.com/blog/how-we-optimized-package-imports-in-next-js)
-
-### 2.2 Conditional Module Loading
-
-**Impact: HIGH (loads large data only when needed)**
-
-Load large data or modules only when a feature is activated.
-
-**Example: lazy-load animation frames**
-
-```tsx
-function AnimationPlayer({ enabled }: { enabled: boolean }) {
- const [frames, setFrames] = useState(null)
-
- useEffect(() => {
- if (enabled && !frames && typeof window !== 'undefined') {
- import('./animation-frames.js')
- .then(mod => setFrames(mod.frames))
- .catch(() => setEnabled(false))
- }
- }, [enabled, frames])
-
- if (!frames) return
- Open Editor
-
- )
-}
-```
-
-**Example: preload when feature flag is enabled**
-
-```tsx
-function FlagsProvider({ children, flags }: Props) {
- useEffect(() => {
- if (flags.editorEnabled && typeof window !== 'undefined') {
- void import('./monaco-editor').then(mod => mod.init())
- }
- }, [flags.editorEnabled])
-
- return
- {children}
-
-}
-```
-
-The `typeof window !== 'undefined'` check prevents bundling preloaded modules for SSR, optimizing server bundle size and build speed.
-
----
-
-## 3. Server-Side Performance
-
-**Impact: HIGH**
-
-Optimizing server-side rendering and data fetching eliminates server-side waterfalls and reduces response times.
-
-### 3.1 Cross-Request LRU Caching
-
-**Impact: HIGH (caches across requests)**
-
-`React.cache()` only works within one request. For data shared across sequential requests (user clicks button A then button B), use an LRU cache.
-
-**Implementation:**
-
-```typescript
-import { LRUCache } from 'lru-cache'
-
-const cache = new LRUCache({
- max: 1000,
- ttl: 5 * 60 * 1000 // 5 minutes
-})
-
-export async function getUser(id: string) {
- const cached = cache.get(id)
- if (cached) return cached
-
- const user = await db.user.findUnique({ where: { id } })
- cache.set(id, user)
- return user
-}
-
-// Request 1: DB query, result cached
-// Request 2: cache hit, no DB query
-```
-
-Use when sequential user actions hit multiple endpoints needing the same data within seconds.
-
-**With Vercel's [Fluid Compute](https://vercel.com/docs/fluid-compute):** LRU caching is especially effective because multiple concurrent requests can share the same function instance and cache. This means the cache persists across requests without needing external storage like Redis.
-
-**In traditional serverless:** Each invocation runs in isolation, so consider Redis for cross-process caching.
-
-Reference: [https://github.com/isaacs/node-lru-cache](https://github.com/isaacs/node-lru-cache)
-
-### 3.2 Minimize Serialization at RSC Boundaries
-
-**Impact: HIGH (reduces data transfer size)**
-
-The React Server/Client boundary serializes all object properties into strings and embeds them in the HTML response and subsequent RSC requests. This serialized data directly impacts page weight and load time, so **size matters a lot**. Only pass fields that the client actually uses.
-
-**Incorrect: serializes all 50 fields**
-
-```tsx
-async function Page() {
- const user = await fetchUser() // 50 fields
- return {user.name}
// uses 1 field
-}
-```
-
-**Correct: serializes only 1 field**
-
-```tsx
-async function Page() {
- const user = await fetchUser()
- return {name}
-}
-```
-
-### 3.3 Parallel Data Fetching with Component Composition
-
-**Impact: CRITICAL (eliminates server-side waterfalls)**
-
-React Server Components execute sequentially within a tree. Restructure with composition to parallelize data fetching.
-
-**Incorrect: Sidebar waits for Page's fetch to complete**
-
-```tsx
-export default async function Page() {
- const header = await fetchHeader()
- return (
-
- )
-}
-
-async function Sidebar() {
- const items = await fetchSidebarItems()
- return {items.map(renderItem)}
-}
-```
-
-**Correct: both fetch simultaneously**
-
-```tsx
-async function Header() {
- const data = await fetchHeader()
- return {data}
-}
-
-async function Sidebar() {
- const items = await fetchSidebarItems()
- return {items.map(renderItem)}
-}
-
-export default function Page() {
- return (
-
-
-
- )
-}
-```
-
-**Alternative with children prop:**
-
-```tsx
-async function Layout({ children }: { children: ReactNode }) {
- const header = await fetchHeader()
- return (
-
-
{header}
- {children}
-
{items.map(renderItem)}
-}
-
-export default function Page() {
- return (
-
-
- )
-}
-```
-
-### 3.4 Per-Request Deduplication with React.cache()
-
-**Impact: MEDIUM (deduplicates within request)**
-
-Use `React.cache()` for server-side request deduplication. Authentication and database queries benefit most.
-
-**Usage:**
-
-```typescript
-import { cache } from 'react'
-
-export const getCurrentUser = cache(async () => {
- const session = await auth()
- if (!session?.user?.id) return null
- return await db.user.findUnique({
- where: { id: session.user.id }
- })
-})
-```
-
-Within a single request, multiple calls to `getCurrentUser()` execute the query only once.
-
-### 3.5 Use after() for Non-Blocking Operations
-
-**Impact: MEDIUM (faster response times)**
-
-Use Next.js's `after()` to schedule work that should execute after a response is sent. This prevents logging, analytics, and other side effects from blocking the response.
-
-**Incorrect: blocks response**
-
-```tsx
-import { logUserAction } from '@/app/utils'
-
-export async function POST(request: Request) {
- // Perform mutation
- await updateDatabase(request)
-
- // Logging blocks the response
- const userAgent = request.headers.get('user-agent') || 'unknown'
- await logUserAction({ userAgent })
-
- return new Response(JSON.stringify({ status: 'success' }), {
- status: 200,
- headers: { 'Content-Type': 'application/json' }
- })
-}
-```
-
-**Correct: non-blocking**
-
-```tsx
-import { after } from 'next/server'
-import { headers, cookies } from 'next/headers'
-import { logUserAction } from '@/app/utils'
-
-export async function POST(request: Request) {
- // Perform mutation
- await updateDatabase(request)
-
- // Log after response is sent
- after(async () => {
- const userAgent = (await headers()).get('user-agent') || 'unknown'
- const sessionCookie = (await cookies()).get('session-id')?.value || 'anonymous'
-
- logUserAction({ sessionCookie, userAgent })
- })
-
- return new Response(JSON.stringify({ status: 'success' }), {
- status: 200,
- headers: { 'Content-Type': 'application/json' }
- })
-}
-```
-
-The response is sent immediately while logging happens in the background.
-
-**Common use cases:**
-
-- Analytics tracking
-
-- Audit logging
-
-- Sending notifications
-
-- Cache invalidation
-
-- Cleanup tasks
-
-**Important notes:**
-
-- `after()` runs even if the response fails or redirects
-
-- Works in Server Actions, Route Handlers, and Server Components
-
-Reference: [https://nextjs.org/docs/app/api-reference/functions/after](https://nextjs.org/docs/app/api-reference/functions/after)
-
----
-
-## 4. Client-Side Data Fetching
-
-**Impact: MEDIUM-HIGH**
-
-Automatic deduplication and efficient data fetching patterns reduce redundant network requests.
-
-### 4.1 Deduplicate Global Event Listeners
-
-**Impact: LOW (single listener for N components)**
-
-Use `useSWRSubscription()` to share global event listeners across component instances.
-
-**Incorrect: N instances = N listeners**
-
-```tsx
-function useKeyboardShortcut(key: string, callback: () => void) {
- useEffect(() => {
- const handler = (e: KeyboardEvent) => {
- if (e.metaKey && e.key === key) {
- callback()
- }
- }
- window.addEventListener('keydown', handler)
- return () => window.removeEventListener('keydown', handler)
- }, [key, callback])
-}
-```
-
-When using the `useKeyboardShortcut` hook multiple times, each instance will register a new listener.
-
-**Correct: N instances = 1 listener**
-
-```tsx
-import useSWRSubscription from 'swr/subscription'
-
-// Module-level Map to track callbacks per key
-const keyCallbacks = new Map void>>()
-
-function useKeyboardShortcut(key: string, callback: () => void) {
- // Register this callback in the Map
- useEffect(() => {
- if (!keyCallbacks.has(key)) {
- keyCallbacks.set(key, new Set())
- }
- keyCallbacks.get(key)!.add(callback)
-
- return () => {
- const set = keyCallbacks.get(key)
- if (set) {
- set.delete(callback)
- if (set.size === 0) {
- keyCallbacks.delete(key)
- }
- }
- }
- }, [key, callback])
-
- useSWRSubscription('global-keydown', () => {
- const handler = (e: KeyboardEvent) => {
- if (e.metaKey && keyCallbacks.has(e.key)) {
- keyCallbacks.get(e.key)!.forEach(cb => cb())
- }
- }
- window.addEventListener('keydown', handler)
- return () => window.removeEventListener('keydown', handler)
- })
-}
-
-function Profile() {
- // Multiple shortcuts will share the same listener
- useKeyboardShortcut('p', () => { /* ... */ })
- useKeyboardShortcut('k', () => { /* ... */ })
- // ...
-}
-```
-
-### 4.2 Use SWR for Automatic Deduplication
-
-**Impact: MEDIUM-HIGH (automatic deduplication)**
-
-SWR enables request deduplication, caching, and revalidation across component instances.
-
-**Incorrect: no deduplication, each instance fetches**
-
-```tsx
-function UserList() {
- const [users, setUsers] = useState([])
- useEffect(() => {
- fetch('/api/users')
- .then(r => r.json())
- .then(setUsers)
- }, [])
-}
-```
-
-**Correct: multiple instances share one request**
-
-```tsx
-import useSWR from 'swr'
-
-function UserList() {
- const { data: users } = useSWR('/api/users', fetcher)
-}
-```
-
-**For immutable data:**
-
-```tsx
-import { useImmutableSWR } from '@/lib/swr'
-
-function StaticContent() {
- const { data } = useImmutableSWR('/api/config', fetcher)
-}
-```
-
-**For mutations:**
-
-```tsx
-import { useSWRMutation } from 'swr/mutation'
-
-function UpdateButton() {
- const { trigger } = useSWRMutation('/api/user', updateUser)
- return trigger()}>Update
-}
-```
-
-Reference: [https://swr.vercel.app](https://swr.vercel.app)
-
----
-
-## 5. Re-render Optimization
-
-**Impact: MEDIUM**
-
-Reducing unnecessary re-renders minimizes wasted computation and improves UI responsiveness.
-
-### 5.1 Defer State Reads to Usage Point
-
-**Impact: MEDIUM (avoids unnecessary subscriptions)**
-
-Don't subscribe to dynamic state (searchParams, localStorage) if you only read it inside callbacks.
-
-**Incorrect: subscribes to all searchParams changes**
-
-```tsx
-function ShareButton({ chatId }: { chatId: string }) {
- const searchParams = useSearchParams()
-
- const handleShare = () => {
- const ref = searchParams.get('ref')
- shareChat(chatId, { ref })
- }
-
- return Share
-}
-```
-
-**Correct: reads on demand, no subscription**
-
-```tsx
-function ShareButton({ chatId }: { chatId: string }) {
- const handleShare = () => {
- const params = new URLSearchParams(window.location.search)
- const ref = params.get('ref')
- shareChat(chatId, { ref })
- }
-
- return Share
-}
-```
-
-### 5.2 Extract to Memoized Components
-
-**Impact: MEDIUM (enables early returns)**
-
-Extract expensive work into memoized components to enable early returns before computation.
-
-**Incorrect: computes avatar even when loading**
-
-```tsx
-function Profile({ user, loading }: Props) {
- const avatar = useMemo(() => {
- const id = computeAvatarId(user)
- return {avatar}
-}
-```
-
-**Correct: skips computation when loading**
-
-```tsx
-const UserAvatar = memo(function UserAvatar({ user }: { user: User }) {
- const id = useMemo(() => computeAvatarId(user), [user])
- return
-
- )
-}
-```
-
-**Note:** If your project has [React Compiler](https://react.dev/learn/react-compiler) enabled, manual memoization with `memo()` and `useMemo()` is not necessary. The compiler automatically optimizes re-renders.
-
-### 5.3 Narrow Effect Dependencies
-
-**Impact: LOW (minimizes effect re-runs)**
-
-Specify primitive dependencies instead of objects to minimize effect re-runs.
-
-**Incorrect: re-runs on any user field change**
-
-```tsx
-useEffect(() => {
- console.log(user.id)
-}, [user])
-```
-
-**Correct: re-runs only when id changes**
-
-```tsx
-useEffect(() => {
- console.log(user.id)
-}, [user.id])
-```
-
-**For derived state, compute outside effect:**
-
-```tsx
-// Incorrect: runs on width=767, 766, 765...
-useEffect(() => {
- if (width < 768) {
- enableMobileMode()
- }
-}, [width])
-
-// Correct: runs only on boolean transition
-const isMobile = width < 768
-useEffect(() => {
- if (isMobile) {
- enableMobileMode()
- }
-}, [isMobile])
-```
-
-### 5.4 Subscribe to Derived State
-
-**Impact: MEDIUM (reduces re-render frequency)**
-
-Subscribe to derived boolean state instead of continuous values to reduce re-render frequency.
-
-**Incorrect: re-renders on every pixel change**
-
-```tsx
-function Sidebar() {
- const width = useWindowWidth() // updates continuously
- const isMobile = width < 768
- return
-}
-```
-
-**Correct: re-renders only when boolean changes**
-
-```tsx
-function Sidebar() {
- const isMobile = useMediaQuery('(max-width: 767px)')
- return
-}
-```
-
-### 5.5 Use Functional setState Updates
-
-**Impact: MEDIUM (prevents stale closures and unnecessary callback recreations)**
-
-When updating state based on the current state value, use the functional update form of setState instead of directly referencing the state variable. This prevents stale closures, eliminates unnecessary dependencies, and creates stable callback references.
-
-**Incorrect: requires state as dependency**
-
-```tsx
-function TodoList() {
- const [items, setItems] = useState(initialItems)
-
- // Callback must depend on items, recreated on every items change
- const addItems = useCallback((newItems: Item[]) => {
- setItems([...items, ...newItems])
- }, [items]) // ❌ items dependency causes recreations
-
- // Risk of stale closure if dependency is forgotten
- const removeItem = useCallback((id: string) => {
- setItems(items.filter(item => item.id !== id))
- }, []) // ❌ Missing items dependency - will use stale items!
-
- return ` and animate the wrapper instead.
-
-**Incorrect: animating SVG directly - no hardware acceleration**
-
-```tsx
-function LoadingSpinner() {
- return (
-
-
- )
-}
-```
-
-**Correct: animating wrapper div - hardware accelerated**
-
-```tsx
-function LoadingSpinner() {
- return (
-
-
-
-
- )
-}
-```
-
-This applies to all CSS transforms and transitions (`transform`, `opacity`, `translate`, `scale`, `rotate`). The wrapper div allows browsers to use GPU acceleration for smoother animations.
-
-### 6.2 CSS content-visibility for Long Lists
-
-**Impact: HIGH (faster initial render)**
-
-Apply `content-visibility: auto` to defer off-screen rendering.
-
-**CSS:**
-
-```css
-.message-item {
- content-visibility: auto;
- contain-intrinsic-size: 0 80px;
-}
-```
-
-**Example:**
-
-```tsx
-function MessageList({ messages }: { messages: Message[] }) {
- return (
-
- {messages.map(msg => (
-
- ))}
-
- )
-}
-```
-
-For 1000 messages, browser skips layout/paint for ~990 off-screen items (10× faster initial render).
-
-### 6.3 Hoist Static JSX Elements
-
-**Impact: LOW (avoids re-creation)**
-
-Extract static JSX outside components to avoid re-creation.
-
-**Incorrect: recreates element every render**
-
-```tsx
-function LoadingSkeleton() {
- return
-}
-
-function Container() {
- return (
-
- {loading &&
- )
-}
-```
-
-**Correct: reuses same element**
-
-```tsx
-const loadingSkeleton = (
-
-)
-
-function Container() {
- return (
-
- {loading && loadingSkeleton}
-
- )
-}
-```
-
-This is especially helpful for large and static SVG nodes, which can be expensive to recreate on every render.
-
-**Note:** If your project has [React Compiler](https://react.dev/learn/react-compiler) enabled, the compiler automatically hoists static JSX elements and optimizes component re-renders, making manual hoisting unnecessary.
-
-### 6.4 Optimize SVG Precision
-
-**Impact: LOW (reduces file size)**
-
-Reduce SVG coordinate precision to decrease file size. The optimal precision depends on the viewBox size, but in general reducing precision should be considered.
-
-**Incorrect: excessive precision**
-
-```svg
-
-```
-
-**Correct: 1 decimal place**
-
-```svg
-
-```
-
-**Automate with SVGO:**
-
-```bash
-npx svgo --precision=1 --multipass icon.svg
-```
-
-### 6.5 Prevent Hydration Mismatch Without Flickering
-
-**Impact: MEDIUM (avoids visual flicker and hydration errors)**
-
-When rendering content that depends on client-side storage (localStorage, cookies), avoid both SSR breakage and post-hydration flickering by injecting a synchronous script that updates the DOM before React hydrates.
-
-**Incorrect: breaks SSR**
-
-```tsx
-function ThemeWrapper({ children }: { children: ReactNode }) {
- // localStorage is not available on server - throws error
- const theme = localStorage.getItem('theme') || 'light'
-
- return (
-
- {children}
-
- )
-}
-```
-
-Server-side rendering will fail because `localStorage` is undefined.
-
-**Incorrect: visual flickering**
-
-```tsx
-function ThemeWrapper({ children }: { children: ReactNode }) {
- const [theme, setTheme] = useState('light')
-
- useEffect(() => {
- // Runs after hydration - causes visible flash
- const stored = localStorage.getItem('theme')
- if (stored) {
- setTheme(stored)
- }
- }, [])
-
- return (
-
- {children}
-
- )
-}
-```
-
-Component first renders with default value (`light`), then updates after hydration, causing a visible flash of incorrect content.
-
-**Correct: no flicker, no hydration mismatch**
-
-```tsx
-function ThemeWrapper({ children }: { children: ReactNode }) {
- return (
- <>
-
- {children}
-
-
-
- )
-}
-```
-
-The inline script executes synchronously before showing the element, ensuring the DOM already has the correct value. No flickering, no hydration mismatch.
-
-This pattern is especially useful for theme toggles, user preferences, authentication states, and any client-only data that should render immediately without flashing default values.
-
-### 6.6 Use Activity Component for Show/Hide
-
-**Impact: MEDIUM (preserves state/DOM)**
-
-Use React's `
` to preserve state/DOM for expensive components that frequently toggle visibility.
-
-**Usage:**
-
-```tsx
-import { Activity } from 'react'
-
-function Dropdown({ isOpen }: Props) {
- return (
-
-
- )
-}
-```
-
-Avoids expensive re-renders and state loss.
-
-### 6.7 Use Explicit Conditional Rendering
-
-**Impact: LOW (prevents rendering 0 or NaN)**
-
-Use explicit ternary operators (`? :`) instead of `&&` for conditional rendering when the condition can be `0`, `NaN`, or other falsy values that render.
-
-**Incorrect: renders "0" when count is 0**
-
-```tsx
-function Badge({ count }: { count: number }) {
- return (
-
- {count && {count} }
-
- )
-}
-
-// When count = 0, renders: 0
-// When count = 5, renders: 5
-```
-
-**Correct: renders nothing when count is 0**
-
-```tsx
-function Badge({ count }: { count: number }) {
- return (
-
- {count > 0 ? {count} : null}
-
- )
-}
-
-// When count = 0, renders:
-// When count = 5, renders: 5
-```
-
----
-
-## 7. JavaScript Performance
-
-**Impact: LOW-MEDIUM**
-
-Micro-optimizations for hot paths can add up to meaningful improvements.
-
-### 7.1 Batch DOM CSS Changes
-
-**Impact: MEDIUM (reduces reflows/repaints)**
-
-Avoid changing styles one property at a time. Group multiple CSS changes together via classes or `cssText` to minimize browser reflows.
-
-**Incorrect: multiple reflows**
-
-```typescript
-function updateElementStyles(element: HTMLElement) {
- // Each line triggers a reflow
- element.style.width = '100px'
- element.style.height = '200px'
- element.style.backgroundColor = 'blue'
- element.style.border = '1px solid black'
-}
-```
-
-**Correct: add class - single reflow**
-
-```typescript
-// CSS file
-.highlighted-box {
- width: 100px;
- height: 200px;
- background-color: blue;
- border: 1px solid black;
-}
-
-// JavaScript
-function updateElementStyles(element: HTMLElement) {
- element.classList.add('highlighted-box')
-}
-```
-
-**Correct: change cssText - single reflow**
-
-```typescript
-function updateElementStyles(element: HTMLElement) {
- element.style.cssText = `
- width: 100px;
- height: 200px;
- background-color: blue;
- border: 1px solid black;
- `
-}
-```
-
-**React example:**
-
-```tsx
-// Incorrect: changing styles one by one
-function Box({ isHighlighted }: { isHighlighted: boolean }) {
- const ref = useRef(null)
-
- useEffect(() => {
- if (ref.current && isHighlighted) {
- ref.current.style.width = '100px'
- ref.current.style.height = '200px'
- ref.current.style.backgroundColor = 'blue'
- }
- }, [isHighlighted])
-
- return Content
-}
-
-// Correct: toggle class
-function Box({ isHighlighted }: { isHighlighted: boolean }) {
- return (
-
- Content
-
- )
-}
-```
-
-Prefer CSS classes over inline styles when possible. Classes are cached by the browser and provide better separation of concerns.
-
-### 7.2 Build Index Maps for Repeated Lookups
-
-**Impact: LOW-MEDIUM (1M ops to 2K ops)**
-
-Multiple `.find()` calls by the same key should use a Map.
-
-**Incorrect (O(n) per lookup):**
-
-```typescript
-function processOrders(orders: Order[], users: User[]) {
- return orders.map(order => ({
- ...order,
- user: users.find(u => u.id === order.userId)
- }))
-}
-```
-
-**Correct (O(1) per lookup):**
-
-```typescript
-function processOrders(orders: Order[], users: User[]) {
- const userById = new Map(users.map(u => [u.id, u]))
-
- return orders.map(order => ({
- ...order,
- user: userById.get(order.userId)
- }))
-}
-```
-
-Build map once (O(n)), then all lookups are O(1).
-
-For 1000 orders × 1000 users: 1M ops → 2K ops.
-
-### 7.3 Cache Property Access in Loops
-
-**Impact: LOW-MEDIUM (reduces lookups)**
-
-Cache object property lookups in hot paths.
-
-**Incorrect: 3 lookups × N iterations**
-
-```typescript
-for (let i = 0; i < arr.length; i++) {
- process(obj.config.settings.value)
-}
-```
-
-**Correct: 1 lookup total**
-
-```typescript
-const value = obj.config.settings.value
-const len = arr.length
-for (let i = 0; i < len; i++) {
- process(value)
-}
-```
-
-### 7.4 Cache Repeated Function Calls
-
-**Impact: MEDIUM (avoid redundant computation)**
-
-Use a module-level Map to cache function results when the same function is called repeatedly with the same inputs during render.
-
-**Incorrect: redundant computation**
-
-```typescript
-function ProjectList({ projects }: { projects: Project[] }) {
- return (
-
- {projects.map(project => {
- // slugify() called 100+ times for same project names
- const slug = slugify(project.name)
-
- return
- })}
-
()
-
-function cachedSlugify(text: string): string {
- if (slugifyCache.has(text)) {
- return slugifyCache.get(text)!
- }
- const result = slugify(text)
- slugifyCache.set(text, result)
- return result
-}
-
-function ProjectList({ projects }: { projects: Project[] }) {
- return (
-
- {projects.map(project => {
- // Computed only once per unique project name
- const slug = cachedSlugify(project.name)
-
- return
- })}
-
()
-
-function getLocalStorage(key: string) {
- if (!storageCache.has(key)) {
- storageCache.set(key, localStorage.getItem(key))
- }
- return storageCache.get(key)
-}
-
-function setLocalStorage(key: string, value: string) {
- localStorage.setItem(key, value)
- storageCache.set(key, value) // keep cache in sync
-}
-```
-
-Use a Map (not a hook) so it works everywhere: utilities, event handlers, not just React components.
-
-**Cookie caching:**
-
-```typescript
-let cookieCache: Record | null = null
-
-function getCookie(name: string) {
- if (!cookieCache) {
- cookieCache = Object.fromEntries(
- document.cookie.split('; ').map(c => c.split('='))
- )
- }
- return cookieCache[name]
-}
-```
-
-**Important: invalidate on external changes**
-
-```typescript
-window.addEventListener('storage', (e) => {
- if (e.key) storageCache.delete(e.key)
-})
-
-document.addEventListener('visibilitychange', () => {
- if (document.visibilityState === 'visible') {
- storageCache.clear()
- }
-})
-```
-
-If storage can change externally (another tab, server-set cookies), invalidate cache:
-
-### 7.6 Combine Multiple Array Iterations
-
-**Impact: LOW-MEDIUM (reduces iterations)**
-
-Multiple `.filter()` or `.map()` calls iterate the array multiple times. Combine into one loop.
-
-**Incorrect: 3 iterations**
-
-```typescript
-const admins = users.filter(u => u.isAdmin)
-const testers = users.filter(u => u.isTester)
-const inactive = users.filter(u => !u.isActive)
-```
-
-**Correct: 1 iteration**
-
-```typescript
-const admins: User[] = []
-const testers: User[] = []
-const inactive: User[] = []
-
-for (const user of users) {
- if (user.isAdmin) admins.push(user)
- if (user.isTester) testers.push(user)
- if (!user.isActive) inactive.push(user)
-}
-```
-
-### 7.7 Early Length Check for Array Comparisons
-
-**Impact: MEDIUM-HIGH (avoids expensive operations when lengths differ)**
-
-When comparing arrays with expensive operations (sorting, deep equality, serialization), check lengths first. If lengths differ, the arrays cannot be equal.
-
-In real-world applications, this optimization is especially valuable when the comparison runs in hot paths (event handlers, render loops).
-
-**Incorrect: always runs expensive comparison**
-
-```typescript
-function hasChanges(current: string[], original: string[]) {
- // Always sorts and joins, even when lengths differ
- return current.sort().join() !== original.sort().join()
-}
-```
-
-Two O(n log n) sorts run even when `current.length` is 5 and `original.length` is 100. There is also overhead of joining the arrays and comparing the strings.
-
-**Correct (O(1) length check first):**
-
-```typescript
-function hasChanges(current: string[], original: string[]) {
- // Early return if lengths differ
- if (current.length !== original.length) {
- return true
- }
- // Only sort/join when lengths match
- const currentSorted = current.toSorted()
- const originalSorted = original.toSorted()
- for (let i = 0; i < currentSorted.length; i++) {
- if (currentSorted[i] !== originalSorted[i]) {
- return true
- }
- }
- return false
-}
-```
-
-This new approach is more efficient because:
-
-- It avoids the overhead of sorting and joining the arrays when lengths differ
-
-- It avoids consuming memory for the joined strings (especially important for large arrays)
-
-- It avoids mutating the original arrays
-
-- It returns early when a difference is found
-
-### 7.8 Early Return from Functions
-
-**Impact: LOW-MEDIUM (avoids unnecessary computation)**
-
-Return early when result is determined to skip unnecessary processing.
-
-**Incorrect: processes all items even after finding answer**
-
-```typescript
-function validateUsers(users: User[]) {
- let hasError = false
- let errorMessage = ''
-
- for (const user of users) {
- if (!user.email) {
- hasError = true
- errorMessage = 'Email required'
- }
- if (!user.name) {
- hasError = true
- errorMessage = 'Name required'
- }
- // Continues checking all users even after error found
- }
-
- return hasError ? { valid: false, error: errorMessage } : { valid: true }
-}
-```
-
-**Correct: returns immediately on first error**
-
-```typescript
-function validateUsers(users: User[]) {
- for (const user of users) {
- if (!user.email) {
- return { valid: false, error: 'Email required' }
- }
- if (!user.name) {
- return { valid: false, error: 'Name required' }
- }
- }
-
- return { valid: true }
-}
-```
-
-### 7.9 Hoist RegExp Creation
-
-**Impact: LOW-MEDIUM (avoids recreation)**
-
-Don't create RegExp inside render. Hoist to module scope or memoize with `useMemo()`.
-
-**Incorrect: new RegExp every render**
-
-```tsx
-function Highlighter({ text, query }: Props) {
- const regex = new RegExp(`(${query})`, 'gi')
- const parts = text.split(regex)
- return <>{parts.map((part, i) => ...)}
-}
-```
-
-**Correct: memoize or hoist**
-
-```tsx
-const EMAIL_REGEX = /^[^\s@]+@[^\s@]+\.[^\s@]+$/
-
-function Highlighter({ text, query }: Props) {
- const regex = useMemo(
- () => new RegExp(`(${escapeRegex(query)})`, 'gi'),
- [query]
- )
- const parts = text.split(regex)
- return <>{parts.map((part, i) => ...)}
-}
-```
-
-**Warning: global regex has mutable state**
-
-```typescript
-const regex = /foo/g
-regex.test('foo') // true, lastIndex = 3
-regex.test('foo') // false, lastIndex = 0
-```
-
-Global regex (`/g`) has mutable `lastIndex` state:
-
-### 7.10 Use Loop for Min/Max Instead of Sort
-
-**Impact: LOW (O(n) instead of O(n log n))**
-
-Finding the smallest or largest element only requires a single pass through the array. Sorting is wasteful and slower.
-
-**Incorrect (O(n log n) - sort to find latest):**
-
-```typescript
-interface Project {
- id: string
- name: string
- updatedAt: number
-}
-
-function getLatestProject(projects: Project[]) {
- const sorted = [...projects].sort((a, b) => b.updatedAt - a.updatedAt)
- return sorted[0]
-}
-```
-
-Sorts the entire array just to find the maximum value.
-
-**Incorrect (O(n log n) - sort for oldest and newest):**
-
-```typescript
-function getOldestAndNewest(projects: Project[]) {
- const sorted = [...projects].sort((a, b) => a.updatedAt - b.updatedAt)
- return { oldest: sorted[0], newest: sorted[sorted.length - 1] }
-}
-```
-
-Still sorts unnecessarily when only min/max are needed.
-
-**Correct (O(n) - single loop):**
-
-```typescript
-function getLatestProject(projects: Project[]) {
- if (projects.length === 0) return null
-
- let latest = projects[0]
-
- for (let i = 1; i < projects.length; i++) {
- if (projects[i].updatedAt > latest.updatedAt) {
- latest = projects[i]
- }
- }
-
- return latest
-}
-
-function getOldestAndNewest(projects: Project[]) {
- if (projects.length === 0) return { oldest: null, newest: null }
-
- let oldest = projects[0]
- let newest = projects[0]
-
- for (let i = 1; i < projects.length; i++) {
- if (projects[i].updatedAt < oldest.updatedAt) oldest = projects[i]
- if (projects[i].updatedAt > newest.updatedAt) newest = projects[i]
- }
-
- return { oldest, newest }
-}
-```
-
-Single pass through the array, no copying, no sorting.
-
-**Alternative: Math.min/Math.max for small arrays**
-
-```typescript
-const numbers = [5, 2, 8, 1, 9]
-const min = Math.min(...numbers)
-const max = Math.max(...numbers)
-```
-
-This works for small arrays but can be slower for very large arrays due to spread operator limitations. Use the loop approach for reliability.
-
-### 7.11 Use Set/Map for O(1) Lookups
-
-**Impact: LOW-MEDIUM (O(n) to O(1))**
-
-Convert arrays to Set/Map for repeated membership checks.
-
-**Incorrect (O(n) per check):**
-
-```typescript
-const allowedIds = ['a', 'b', 'c', ...]
-items.filter(item => allowedIds.includes(item.id))
-```
-
-**Correct (O(1) per check):**
-
-```typescript
-const allowedIds = new Set(['a', 'b', 'c', ...])
-items.filter(item => allowedIds.has(item.id))
-```
-
-### 7.12 Use toSorted() Instead of sort() for Immutability
-
-**Impact: MEDIUM-HIGH (prevents mutation bugs in React state)**
-
-`.sort()` mutates the array in place, which can cause bugs with React state and props. Use `.toSorted()` to create a new sorted array without mutation.
-
-**Incorrect: mutates original array**
-
-```typescript
-function UserList({ users }: { users: User[] }) {
- // Mutates the users prop array!
- const sorted = useMemo(
- () => users.sort((a, b) => a.name.localeCompare(b.name)),
- [users]
- )
- return {sorted.map(renderUser)}
-}
-```
-
-**Correct: creates new array**
-
-```typescript
-function UserList({ users }: { users: User[] }) {
- // Creates new sorted array, original unchanged
- const sorted = useMemo(
- () => users.toSorted((a, b) => a.name.localeCompare(b.name)),
- [users]
- )
- return {sorted.map(renderUser)}
-}
-```
-
-**Why this matters in React:**
-
-1. Props/state mutations break React's immutability model - React expects props and state to be treated as read-only
-
-2. Causes stale closure bugs - Mutating arrays inside closures (callbacks, effects) can lead to unexpected behavior
-
-**Browser support: fallback for older browsers**
-
-```typescript
-// Fallback for older browsers
-const sorted = [...items].sort((a, b) => a.value - b.value)
-```
-
-`.toSorted()` is available in all modern browsers (Chrome 110+, Safari 16+, Firefox 115+, Node.js 20+). For older environments, use spread operator:
-
-**Other immutable array methods:**
-
-- `.toSorted()` - immutable sort
-
-- `.toReversed()` - immutable reverse
-
-- `.toSpliced()` - immutable splice
-
-- `.with()` - immutable element replacement
-
----
-
-## 8. Advanced Patterns
-
-**Impact: LOW**
-
-Advanced patterns for specific cases that require careful implementation.
-
-### 8.1 Store Event Handlers in Refs
-
-**Impact: LOW (stable subscriptions)**
-
-Store callbacks in refs when used in effects that shouldn't re-subscribe on callback changes.
-
-**Incorrect: re-subscribes on every render**
-
-```tsx
-function useWindowEvent(event: string, handler: () => void) {
- useEffect(() => {
- window.addEventListener(event, handler)
- return () => window.removeEventListener(event, handler)
- }, [event, handler])
-}
-```
-
-**Correct: stable subscription**
-
-```tsx
-import { useEffectEvent } from 'react'
-
-function useWindowEvent(event: string, handler: () => void) {
- const onEvent = useEffectEvent(handler)
-
- useEffect(() => {
- window.addEventListener(event, onEvent)
- return () => window.removeEventListener(event, onEvent)
- }, [event])
-}
-```
-
-**Alternative: use `useEffectEvent` if you're on latest React:**
-
-`useEffectEvent` provides a cleaner API for the same pattern: it creates a stable function reference that always calls the latest version of the handler.
-
-### 8.2 useLatest for Stable Callback Refs
-
-**Impact: LOW (prevents effect re-runs)**
-
-Access latest values in callbacks without adding them to dependency arrays. Prevents effect re-runs while avoiding stale closures.
-
-**Implementation:**
-
-```typescript
-function useLatest(value: T) {
- const ref = useRef(value)
- useEffect(() => {
- ref.current = value
- }, [value])
- return ref
-}
-```
-
-**Incorrect: effect re-runs on every callback change**
-
-```tsx
-function SearchInput({ onSearch }: { onSearch: (q: string) => void }) {
- const [query, setQuery] = useState('')
-
- useEffect(() => {
- const timeout = setTimeout(() => onSearch(query), 300)
- return () => clearTimeout(timeout)
- }, [query, onSearch])
-}
-```
-
-**Correct: stable effect, fresh callback**
-
-```tsx
-function SearchInput({ onSearch }: { onSearch: (q: string) => void }) {
- const [query, setQuery] = useState('')
- const onSearchRef = useLatest(onSearch)
-
- useEffect(() => {
- const timeout = setTimeout(() => onSearchRef.current(query), 300)
- return () => clearTimeout(timeout)
- }, [query])
-}
-```
-
----
-
-## References
-
-1. [https://react.dev](https://react.dev)
-2. [https://nextjs.org](https://nextjs.org)
-3. [https://swr.vercel.app](https://swr.vercel.app)
-4. [https://github.com/shuding/better-all](https://github.com/shuding/better-all)
-5. [https://github.com/isaacs/node-lru-cache](https://github.com/isaacs/node-lru-cache)
-6. [https://vercel.com/blog/how-we-optimized-package-imports-in-next-js](https://vercel.com/blog/how-we-optimized-package-imports-in-next-js)
-7. [https://vercel.com/blog/how-we-made-the-vercel-dashboard-twice-as-fast](https://vercel.com/blog/how-we-made-the-vercel-dashboard-twice-as-fast)
diff --git a/.github/skills/vercel-react-best-practices/README.md b/.github/skills/vercel-react-best-practices/README.md
deleted file mode 100644
index f283e1c0..00000000
--- a/.github/skills/vercel-react-best-practices/README.md
+++ /dev/null
@@ -1,123 +0,0 @@
-# React Best Practices
-
-A structured repository for creating and maintaining React Best Practices optimized for agents and LLMs.
-
-## Structure
-
-- `rules/` - Individual rule files (one per rule)
- - `_sections.md` - Section metadata (titles, impacts, descriptions)
- - `_template.md` - Template for creating new rules
- - `area-description.md` - Individual rule files
-- `src/` - Build scripts and utilities
-- `metadata.json` - Document metadata (version, organization, abstract)
-- __`AGENTS.md`__ - Compiled output (generated)
-- __`test-cases.json`__ - Test cases for LLM evaluation (generated)
-
-## Getting Started
-
-1. Install dependencies:
- ```bash
- pnpm install
- ```
-
-2. Build AGENTS.md from rules:
- ```bash
- pnpm build
- ```
-
-3. Validate rule files:
- ```bash
- pnpm validate
- ```
-
-4. Extract test cases:
- ```bash
- pnpm extract-tests
- ```
-
-## Creating a New Rule
-
-1. Copy `rules/_template.md` to `rules/area-description.md`
-2. Choose the appropriate area prefix:
- - `async-` for Eliminating Waterfalls (Section 1)
- - `bundle-` for Bundle Size Optimization (Section 2)
- - `server-` for Server-Side Performance (Section 3)
- - `client-` for Client-Side Data Fetching (Section 4)
- - `rerender-` for Re-render Optimization (Section 5)
- - `rendering-` for Rendering Performance (Section 6)
- - `js-` for JavaScript Performance (Section 7)
- - `advanced-` for Advanced Patterns (Section 8)
-3. Fill in the frontmatter and content
-4. Ensure you have clear examples with explanations
-5. Run `pnpm build` to regenerate AGENTS.md and test-cases.json
-
-## Rule File Structure
-
-Each rule file should follow this structure:
-
-```markdown
----
-title: Rule Title Here
-impact: MEDIUM
-impactDescription: Optional description
-tags: tag1, tag2, tag3
----
-
-## Rule Title Here
-
-Brief explanation of the rule and why it matters.
-
-**Incorrect (description of what's wrong):**
-
-```typescript
-// Bad code example
-```
-
-**Correct (description of what's right):**
-
-```typescript
-// Good code example
-```
-
-Optional explanatory text after examples.
-
-Reference: [Link](https://example.com)
-
-## File Naming Convention
-
-- Files starting with `_` are special (excluded from build)
-- Rule files: `area-description.md` (e.g., `async-parallel.md`)
-- Section is automatically inferred from filename prefix
-- Rules are sorted alphabetically by title within each section
-- IDs (e.g., 1.1, 1.2) are auto-generated during build
-
-## Impact Levels
-
-- `CRITICAL` - Highest priority, major performance gains
-- `HIGH` - Significant performance improvements
-- `MEDIUM-HIGH` - Moderate-high gains
-- `MEDIUM` - Moderate performance improvements
-- `LOW-MEDIUM` - Low-medium gains
-- `LOW` - Incremental improvements
-
-## Scripts
-
-- `pnpm build` - Compile rules into AGENTS.md
-- `pnpm validate` - Validate all rule files
-- `pnpm extract-tests` - Extract test cases for LLM evaluation
-- `pnpm dev` - Build and validate
-
-## Contributing
-
-When adding or modifying rules:
-
-1. Use the correct filename prefix for your section
-2. Follow the `_template.md` structure
-3. Include clear bad/good examples with explanations
-4. Add appropriate tags
-5. Run `pnpm build` to regenerate AGENTS.md and test-cases.json
-6. Rules are automatically sorted by title - no need to manage numbers!
-
-## Acknowledgments
-
-Originally created by [@shuding](https://x.com/shuding) at [Vercel](https://vercel.com).
diff --git a/.github/skills/vercel-react-best-practices/SKILL.md b/.github/skills/vercel-react-best-practices/SKILL.md
deleted file mode 100644
index 25bbe87e..00000000
--- a/.github/skills/vercel-react-best-practices/SKILL.md
+++ /dev/null
@@ -1,121 +0,0 @@
----
-name: vercel-react-best-practices
-description: React and Next.js performance optimization guidelines from Vercel Engineering. This skill should be used when writing, reviewing, or refactoring React/Next.js code to ensure optimal performance patterns. Triggers on tasks involving React components, Next.js pages, data fetching, bundle optimization, or performance improvements.
----
-
-# Vercel React Best Practices
-
-Comprehensive performance optimization guide for React and Next.js applications, maintained by Vercel. Contains 45 rules across 8 categories, prioritized by impact to guide automated refactoring and code generation.
-
-## When to Apply
-
-Reference these guidelines when:
-- Writing new React components or Next.js pages
-- Implementing data fetching (client or server-side)
-- Reviewing code for performance issues
-- Refactoring existing React/Next.js code
-- Optimizing bundle size or load times
-
-## Rule Categories by Priority
-
-| Priority | Category | Impact | Prefix |
-|----------|----------|--------|--------|
-| 1 | Eliminating Waterfalls | CRITICAL | `async-` |
-| 2 | Bundle Size Optimization | CRITICAL | `bundle-` |
-| 3 | Server-Side Performance | HIGH | `server-` |
-| 4 | Client-Side Data Fetching | MEDIUM-HIGH | `client-` |
-| 5 | Re-render Optimization | MEDIUM | `rerender-` |
-| 6 | Rendering Performance | MEDIUM | `rendering-` |
-| 7 | JavaScript Performance | LOW-MEDIUM | `js-` |
-| 8 | Advanced Patterns | LOW | `advanced-` |
-
-## Quick Reference
-
-### 1. Eliminating Waterfalls (CRITICAL)
-
-- `async-defer-await` - Move await into branches where actually used
-- `async-parallel` - Use Promise.all() for independent operations
-- `async-dependencies` - Use better-all for partial dependencies
-- `async-api-routes` - Start promises early, await late in API routes
-- `async-suspense-boundaries` - Use Suspense to stream content
-
-### 2. Bundle Size Optimization (CRITICAL)
-
-- `bundle-barrel-imports` - Import directly, avoid barrel files
-- `bundle-dynamic-imports` - Use next/dynamic for heavy components
-- `bundle-defer-third-party` - Load analytics/logging after hydration
-- `bundle-conditional` - Load modules only when feature is activated
-- `bundle-preload` - Preload on hover/focus for perceived speed
-
-### 3. Server-Side Performance (HIGH)
-
-- `server-cache-react` - Use React.cache() for per-request deduplication
-- `server-cache-lru` - Use LRU cache for cross-request caching
-- `server-serialization` - Minimize data passed to client components
-- `server-parallel-fetching` - Restructure components to parallelize fetches
-- `server-after-nonblocking` - Use after() for non-blocking operations
-
-### 4. Client-Side Data Fetching (MEDIUM-HIGH)
-
-- `client-swr-dedup` - Use SWR for automatic request deduplication
-- `client-event-listeners` - Deduplicate global event listeners
-
-### 5. Re-render Optimization (MEDIUM)
-
-- `rerender-defer-reads` - Don't subscribe to state only used in callbacks
-- `rerender-memo` - Extract expensive work into memoized components
-- `rerender-dependencies` - Use primitive dependencies in effects
-- `rerender-derived-state` - Subscribe to derived booleans, not raw values
-- `rerender-functional-setstate` - Use functional setState for stable callbacks
-- `rerender-lazy-state-init` - Pass function to useState for expensive values
-- `rerender-transitions` - Use startTransition for non-urgent updates
-
-### 6. Rendering Performance (MEDIUM)
-
-- `rendering-animate-svg-wrapper` - Animate div wrapper, not SVG element
-- `rendering-content-visibility` - Use content-visibility for long lists
-- `rendering-hoist-jsx` - Extract static JSX outside components
-- `rendering-svg-precision` - Reduce SVG coordinate precision
-- `rendering-hydration-no-flicker` - Use inline script for client-only data
-- `rendering-activity` - Use Activity component for show/hide
-- `rendering-conditional-render` - Use ternary, not && for conditionals
-
-### 7. JavaScript Performance (LOW-MEDIUM)
-
-- `js-batch-dom-css` - Group CSS changes via classes or cssText
-- `js-index-maps` - Build Map for repeated lookups
-- `js-cache-property-access` - Cache object properties in loops
-- `js-cache-function-results` - Cache function results in module-level Map
-- `js-cache-storage` - Cache localStorage/sessionStorage reads
-- `js-combine-iterations` - Combine multiple filter/map into one loop
-- `js-length-check-first` - Check array length before expensive comparison
-- `js-early-exit` - Return early from functions
-- `js-hoist-regexp` - Hoist RegExp creation outside loops
-- `js-min-max-loop` - Use loop for min/max instead of sort
-- `js-set-map-lookups` - Use Set/Map for O(1) lookups
-- `js-tosorted-immutable` - Use toSorted() for immutability
-
-### 8. Advanced Patterns (LOW)
-
-- `advanced-event-handler-refs` - Store event handlers in refs
-- `advanced-use-latest` - useLatest for stable callback refs
-
-## How to Use
-
-Read individual rule files for detailed explanations and code examples:
-
-```
-rules/async-parallel.md
-rules/bundle-barrel-imports.md
-rules/_sections.md
-```
-
-Each rule file contains:
-- Brief explanation of why it matters
-- Incorrect code example with explanation
-- Correct code example with explanation
-- Additional context and references
-
-## Full Compiled Document
-
-For the complete guide with all rules expanded: `AGENTS.md`
diff --git a/.github/skills/vercel-react-best-practices/metadata.json b/.github/skills/vercel-react-best-practices/metadata.json
deleted file mode 100644
index fcb41079..00000000
--- a/.github/skills/vercel-react-best-practices/metadata.json
+++ /dev/null
@@ -1,15 +0,0 @@
-{
- "version": "0.1.0",
- "organization": "Vercel Engineering",
- "date": "January 2026",
- "abstract": "Comprehensive performance optimization guide for React and Next.js applications, designed for AI agents and LLMs. Contains 40+ rules across 8 categories, prioritized by impact from critical (eliminating waterfalls, reducing bundle size) to incremental (advanced patterns). Each rule includes detailed explanations, real-world examples comparing incorrect vs. correct implementations, and specific impact metrics to guide automated refactoring and code generation.",
- "references": [
- "https://react.dev",
- "https://nextjs.org",
- "https://swr.vercel.app",
- "https://github.com/shuding/better-all",
- "https://github.com/isaacs/node-lru-cache",
- "https://vercel.com/blog/how-we-optimized-package-imports-in-next-js",
- "https://vercel.com/blog/how-we-made-the-vercel-dashboard-twice-as-fast"
- ]
-}
diff --git a/.github/skills/vercel-react-best-practices/rules/_sections.md b/.github/skills/vercel-react-best-practices/rules/_sections.md
deleted file mode 100644
index 4d20c144..00000000
--- a/.github/skills/vercel-react-best-practices/rules/_sections.md
+++ /dev/null
@@ -1,46 +0,0 @@
-# Sections
-
-This file defines all sections, their ordering, impact levels, and descriptions.
-The section ID (in parentheses) is the filename prefix used to group rules.
-
----
-
-## 1. Eliminating Waterfalls (async)
-
-**Impact:** CRITICAL
-**Description:** Waterfalls are the #1 performance killer. Each sequential await adds full network latency. Eliminating them yields the largest gains.
-
-## 2. Bundle Size Optimization (bundle)
-
-**Impact:** CRITICAL
-**Description:** Reducing initial bundle size improves Time to Interactive and Largest Contentful Paint.
-
-## 3. Server-Side Performance (server)
-
-**Impact:** HIGH
-**Description:** Optimizing server-side rendering and data fetching eliminates server-side waterfalls and reduces response times.
-
-## 4. Client-Side Data Fetching (client)
-
-**Impact:** MEDIUM-HIGH
-**Description:** Automatic deduplication and efficient data fetching patterns reduce redundant network requests.
-
-## 5. Re-render Optimization (rerender)
-
-**Impact:** MEDIUM
-**Description:** Reducing unnecessary re-renders minimizes wasted computation and improves UI responsiveness.
-
-## 6. Rendering Performance (rendering)
-
-**Impact:** MEDIUM
-**Description:** Optimizing the rendering process reduces the work the browser needs to do.
-
-## 7. JavaScript Performance (js)
-
-**Impact:** LOW-MEDIUM
-**Description:** Micro-optimizations for hot paths can add up to meaningful improvements.
-
-## 8. Advanced Patterns (advanced)
-
-**Impact:** LOW
-**Description:** Advanced patterns for specific cases that require careful implementation.
diff --git a/.github/skills/vercel-react-best-practices/rules/_template.md b/.github/skills/vercel-react-best-practices/rules/_template.md
deleted file mode 100644
index 1e9e7070..00000000
--- a/.github/skills/vercel-react-best-practices/rules/_template.md
+++ /dev/null
@@ -1,28 +0,0 @@
----
-title: Rule Title Here
-impact: MEDIUM
-impactDescription: Optional description of impact (e.g., "20-50% improvement")
-tags: tag1, tag2
----
-
-## Rule Title Here
-
-**Impact: MEDIUM (optional impact description)**
-
-Brief explanation of the rule and why it matters. This should be clear and concise, explaining the performance implications.
-
-**Incorrect (description of what's wrong):**
-
-```typescript
-// Bad code example here
-const bad = example()
-```
-
-**Correct (description of what's right):**
-
-```typescript
-// Good code example here
-const good = example()
-```
-
-Reference: [Link to documentation or resource](https://example.com)
diff --git a/.github/skills/vercel-react-best-practices/rules/advanced-event-handler-refs.md b/.github/skills/vercel-react-best-practices/rules/advanced-event-handler-refs.md
deleted file mode 100644
index 3a451520..00000000
--- a/.github/skills/vercel-react-best-practices/rules/advanced-event-handler-refs.md
+++ /dev/null
@@ -1,55 +0,0 @@
----
-title: Store Event Handlers in Refs
-impact: LOW
-impactDescription: stable subscriptions
-tags: advanced, hooks, refs, event-handlers, optimization
----
-
-## Store Event Handlers in Refs
-
-Store callbacks in refs when used in effects that shouldn't re-subscribe on callback changes.
-
-**Incorrect (re-subscribes on every render):**
-
-```tsx
-function useWindowEvent(event: string, handler: () => void) {
- useEffect(() => {
- window.addEventListener(event, handler)
- return () => window.removeEventListener(event, handler)
- }, [event, handler])
-}
-```
-
-**Correct (stable subscription):**
-
-```tsx
-function useWindowEvent(event: string, handler: () => void) {
- const handlerRef = useRef(handler)
- useEffect(() => {
- handlerRef.current = handler
- }, [handler])
-
- useEffect(() => {
- const listener = () => handlerRef.current()
- window.addEventListener(event, listener)
- return () => window.removeEventListener(event, listener)
- }, [event])
-}
-```
-
-**Alternative: use `useEffectEvent` if you're on latest React:**
-
-```tsx
-import { useEffectEvent } from 'react'
-
-function useWindowEvent(event: string, handler: () => void) {
- const onEvent = useEffectEvent(handler)
-
- useEffect(() => {
- window.addEventListener(event, onEvent)
- return () => window.removeEventListener(event, onEvent)
- }, [event])
-}
-```
-
-`useEffectEvent` provides a cleaner API for the same pattern: it creates a stable function reference that always calls the latest version of the handler.
diff --git a/.github/skills/vercel-react-best-practices/rules/advanced-use-latest.md b/.github/skills/vercel-react-best-practices/rules/advanced-use-latest.md
deleted file mode 100644
index 3facdf2c..00000000
--- a/.github/skills/vercel-react-best-practices/rules/advanced-use-latest.md
+++ /dev/null
@@ -1,49 +0,0 @@
----
-title: useLatest for Stable Callback Refs
-impact: LOW
-impactDescription: prevents effect re-runs
-tags: advanced, hooks, useLatest, refs, optimization
----
-
-## useLatest for Stable Callback Refs
-
-Access latest values in callbacks without adding them to dependency arrays. Prevents effect re-runs while avoiding stale closures.
-
-**Implementation:**
-
-```typescript
-function useLatest(value: T) {
- const ref = useRef(value)
- useEffect(() => {
- ref.current = value
- }, [value])
- return ref
-}
-```
-
-**Incorrect (effect re-runs on every callback change):**
-
-```tsx
-function SearchInput({ onSearch }: { onSearch: (q: string) => void }) {
- const [query, setQuery] = useState('')
-
- useEffect(() => {
- const timeout = setTimeout(() => onSearch(query), 300)
- return () => clearTimeout(timeout)
- }, [query, onSearch])
-}
-```
-
-**Correct (stable effect, fresh callback):**
-
-```tsx
-function SearchInput({ onSearch }: { onSearch: (q: string) => void }) {
- const [query, setQuery] = useState('')
- const onSearchRef = useLatest(onSearch)
-
- useEffect(() => {
- const timeout = setTimeout(() => onSearchRef.current(query), 300)
- return () => clearTimeout(timeout)
- }, [query])
-}
-```
diff --git a/.github/skills/vercel-react-best-practices/rules/async-api-routes.md b/.github/skills/vercel-react-best-practices/rules/async-api-routes.md
deleted file mode 100644
index 6feda1ef..00000000
--- a/.github/skills/vercel-react-best-practices/rules/async-api-routes.md
+++ /dev/null
@@ -1,38 +0,0 @@
----
-title: Prevent Waterfall Chains in API Routes
-impact: CRITICAL
-impactDescription: 2-10× improvement
-tags: api-routes, server-actions, waterfalls, parallelization
----
-
-## Prevent Waterfall Chains in API Routes
-
-In API routes and Server Actions, start independent operations immediately, even if you don't await them yet.
-
-**Incorrect (config waits for auth, data waits for both):**
-
-```typescript
-export async function GET(request: Request) {
- const session = await auth()
- const config = await fetchConfig()
- const data = await fetchData(session.user.id)
- return Response.json({ data, config })
-}
-```
-
-**Correct (auth and config start immediately):**
-
-```typescript
-export async function GET(request: Request) {
- const sessionPromise = auth()
- const configPromise = fetchConfig()
- const session = await sessionPromise
- const [config, data] = await Promise.all([
- configPromise,
- fetchData(session.user.id)
- ])
- return Response.json({ data, config })
-}
-```
-
-For operations with more complex dependency chains, use `better-all` to automatically maximize parallelism (see Dependency-Based Parallelization).
diff --git a/.github/skills/vercel-react-best-practices/rules/async-defer-await.md b/.github/skills/vercel-react-best-practices/rules/async-defer-await.md
deleted file mode 100644
index ea7082a3..00000000
--- a/.github/skills/vercel-react-best-practices/rules/async-defer-await.md
+++ /dev/null
@@ -1,80 +0,0 @@
----
-title: Defer Await Until Needed
-impact: HIGH
-impactDescription: avoids blocking unused code paths
-tags: async, await, conditional, optimization
----
-
-## Defer Await Until Needed
-
-Move `await` operations into the branches where they're actually used to avoid blocking code paths that don't need them.
-
-**Incorrect (blocks both branches):**
-
-```typescript
-async function handleRequest(userId: string, skipProcessing: boolean) {
- const userData = await fetchUserData(userId)
-
- if (skipProcessing) {
- // Returns immediately but still waited for userData
- return { skipped: true }
- }
-
- // Only this branch uses userData
- return processUserData(userData)
-}
-```
-
-**Correct (only blocks when needed):**
-
-```typescript
-async function handleRequest(userId: string, skipProcessing: boolean) {
- if (skipProcessing) {
- // Returns immediately without waiting
- return { skipped: true }
- }
-
- // Fetch only when needed
- const userData = await fetchUserData(userId)
- return processUserData(userData)
-}
-```
-
-**Another example (early return optimization):**
-
-```typescript
-// Incorrect: always fetches permissions
-async function updateResource(resourceId: string, userId: string) {
- const permissions = await fetchPermissions(userId)
- const resource = await getResource(resourceId)
-
- if (!resource) {
- return { error: 'Not found' }
- }
-
- if (!permissions.canEdit) {
- return { error: 'Forbidden' }
- }
-
- return await updateResourceData(resource, permissions)
-}
-
-// Correct: fetches only when needed
-async function updateResource(resourceId: string, userId: string) {
- const resource = await getResource(resourceId)
-
- if (!resource) {
- return { error: 'Not found' }
- }
-
- const permissions = await fetchPermissions(userId)
-
- if (!permissions.canEdit) {
- return { error: 'Forbidden' }
- }
-
- return await updateResourceData(resource, permissions)
-}
-```
-
-This optimization is especially valuable when the skipped branch is frequently taken, or when the deferred operation is expensive.
diff --git a/.github/skills/vercel-react-best-practices/rules/async-dependencies.md b/.github/skills/vercel-react-best-practices/rules/async-dependencies.md
deleted file mode 100644
index fb90d861..00000000
--- a/.github/skills/vercel-react-best-practices/rules/async-dependencies.md
+++ /dev/null
@@ -1,36 +0,0 @@
----
-title: Dependency-Based Parallelization
-impact: CRITICAL
-impactDescription: 2-10× improvement
-tags: async, parallelization, dependencies, better-all
----
-
-## Dependency-Based Parallelization
-
-For operations with partial dependencies, use `better-all` to maximize parallelism. It automatically starts each task at the earliest possible moment.
-
-**Incorrect (profile waits for config unnecessarily):**
-
-```typescript
-const [user, config] = await Promise.all([
- fetchUser(),
- fetchConfig()
-])
-const profile = await fetchProfile(user.id)
-```
-
-**Correct (config and profile run in parallel):**
-
-```typescript
-import { all } from 'better-all'
-
-const { user, config, profile } = await all({
- async user() { return fetchUser() },
- async config() { return fetchConfig() },
- async profile() {
- return fetchProfile((await this.$.user).id)
- }
-})
-```
-
-Reference: [https://github.com/shuding/better-all](https://github.com/shuding/better-all)
diff --git a/.github/skills/vercel-react-best-practices/rules/async-parallel.md b/.github/skills/vercel-react-best-practices/rules/async-parallel.md
deleted file mode 100644
index 64133f6c..00000000
--- a/.github/skills/vercel-react-best-practices/rules/async-parallel.md
+++ /dev/null
@@ -1,28 +0,0 @@
----
-title: Promise.all() for Independent Operations
-impact: CRITICAL
-impactDescription: 2-10× improvement
-tags: async, parallelization, promises, waterfalls
----
-
-## Promise.all() for Independent Operations
-
-When async operations have no interdependencies, execute them concurrently using `Promise.all()`.
-
-**Incorrect (sequential execution, 3 round trips):**
-
-```typescript
-const user = await fetchUser()
-const posts = await fetchPosts()
-const comments = await fetchComments()
-```
-
-**Correct (parallel execution, 1 round trip):**
-
-```typescript
-const [user, posts, comments] = await Promise.all([
- fetchUser(),
- fetchPosts(),
- fetchComments()
-])
-```
diff --git a/.github/skills/vercel-react-best-practices/rules/async-suspense-boundaries.md b/.github/skills/vercel-react-best-practices/rules/async-suspense-boundaries.md
deleted file mode 100644
index 1fbc05b0..00000000
--- a/.github/skills/vercel-react-best-practices/rules/async-suspense-boundaries.md
+++ /dev/null
@@ -1,99 +0,0 @@
----
-title: Strategic Suspense Boundaries
-impact: HIGH
-impactDescription: faster initial paint
-tags: async, suspense, streaming, layout-shift
----
-
-## Strategic Suspense Boundaries
-
-Instead of awaiting data in async components before returning JSX, use Suspense boundaries to show the wrapper UI faster while data loads.
-
-**Incorrect (wrapper blocked by data fetching):**
-
-```tsx
-async function Page() {
- const data = await fetchData() // Blocks entire page
-
- return (
-
-
Sidebar
-
Header
-
-
-
Footer
-
-
Sidebar
-
Header
-
-
-
Footer
-
{data.content}
-}
-```
-
-Sidebar, Header, and Footer render immediately. Only DataDisplay waits for data.
-
-**Alternative (share promise across components):**
-
-```tsx
-function Page() {
- // Start fetch immediately, but don't await
- const dataPromise = fetchData()
-
- return (
-
-
Sidebar
-
Header
-
}>
-
-
-
-
Footer
-
}) {
- const data = use(dataPromise) // Unwraps the promise
- return {data.content}
-}
-
-function DataSummary({ dataPromise }: { dataPromise: Promise }) {
- const data = use(dataPromise) // Reuses the same promise
- return {data.summary}
-}
-```
-
-Both components share the same promise, so only one fetch occurs. Layout renders immediately while both components wait together.
-
-**When NOT to use this pattern:**
-
-- Critical data needed for layout decisions (affects positioning)
-- SEO-critical content above the fold
-- Small, fast queries where suspense overhead isn't worth it
-- When you want to avoid layout shift (loading → content jump)
-
-**Trade-off:** Faster initial paint vs potential layout shift. Choose based on your UX priorities.
diff --git a/.github/skills/vercel-react-best-practices/rules/bundle-barrel-imports.md b/.github/skills/vercel-react-best-practices/rules/bundle-barrel-imports.md
deleted file mode 100644
index ee48f327..00000000
--- a/.github/skills/vercel-react-best-practices/rules/bundle-barrel-imports.md
+++ /dev/null
@@ -1,59 +0,0 @@
----
-title: Avoid Barrel File Imports
-impact: CRITICAL
-impactDescription: 200-800ms import cost, slow builds
-tags: bundle, imports, tree-shaking, barrel-files, performance
----
-
-## Avoid Barrel File Imports
-
-Import directly from source files instead of barrel files to avoid loading thousands of unused modules. **Barrel files** are entry points that re-export multiple modules (e.g., `index.js` that does `export * from './module'`).
-
-Popular icon and component libraries can have **up to 10,000 re-exports** in their entry file. For many React packages, **it takes 200-800ms just to import them**, affecting both development speed and production cold starts.
-
-**Why tree-shaking doesn't help:** When a library is marked as external (not bundled), the bundler can't optimize it. If you bundle it to enable tree-shaking, builds become substantially slower analyzing the entire module graph.
-
-**Incorrect (imports entire library):**
-
-```tsx
-import { Check, X, Menu } from 'lucide-react'
-// Loads 1,583 modules, takes ~2.8s extra in dev
-// Runtime cost: 200-800ms on every cold start
-
-import { Button, TextField } from '@mui/material'
-// Loads 2,225 modules, takes ~4.2s extra in dev
-```
-
-**Correct (imports only what you need):**
-
-```tsx
-import Check from 'lucide-react/dist/esm/icons/check'
-import X from 'lucide-react/dist/esm/icons/x'
-import Menu from 'lucide-react/dist/esm/icons/menu'
-// Loads only 3 modules (~2KB vs ~1MB)
-
-import Button from '@mui/material/Button'
-import TextField from '@mui/material/TextField'
-// Loads only what you use
-```
-
-**Alternative (Next.js 13.5+):**
-
-```js
-// next.config.js - use optimizePackageImports
-module.exports = {
- experimental: {
- optimizePackageImports: ['lucide-react', '@mui/material']
- }
-}
-
-// Then you can keep the ergonomic barrel imports:
-import { Check, X, Menu } from 'lucide-react'
-// Automatically transformed to direct imports at build time
-```
-
-Direct imports provide 15-70% faster dev boot, 28% faster builds, 40% faster cold starts, and significantly faster HMR.
-
-Libraries commonly affected: `lucide-react`, `@mui/material`, `@mui/icons-material`, `@tabler/icons-react`, `react-icons`, `@headlessui/react`, `@radix-ui/react-*`, `lodash`, `ramda`, `date-fns`, `rxjs`, `react-use`.
-
-Reference: [How we optimized package imports in Next.js](https://vercel.com/blog/how-we-optimized-package-imports-in-next-js)
diff --git a/.github/skills/vercel-react-best-practices/rules/bundle-conditional.md b/.github/skills/vercel-react-best-practices/rules/bundle-conditional.md
deleted file mode 100644
index 40bd6f98..00000000
--- a/.github/skills/vercel-react-best-practices/rules/bundle-conditional.md
+++ /dev/null
@@ -1,31 +0,0 @@
----
-title: Conditional Module Loading
-impact: HIGH
-impactDescription: loads large data only when needed
-tags: bundle, conditional-loading, lazy-loading
----
-
-## Conditional Module Loading
-
-Load large data or modules only when a feature is activated.
-
-**Example (lazy-load animation frames):**
-
-```tsx
-function AnimationPlayer({ enabled }: { enabled: boolean }) {
- const [frames, setFrames] = useState(null)
-
- useEffect(() => {
- if (enabled && !frames && typeof window !== 'undefined') {
- import('./animation-frames.js')
- .then(mod => setFrames(mod.frames))
- .catch(() => setEnabled(false))
- }
- }, [enabled, frames])
-
- if (!frames) return
- Open Editor
-
- )
-}
-```
-
-**Example (preload when feature flag is enabled):**
-
-```tsx
-function FlagsProvider({ children, flags }: Props) {
- useEffect(() => {
- if (flags.editorEnabled && typeof window !== 'undefined') {
- void import('./monaco-editor').then(mod => mod.init())
- }
- }, [flags.editorEnabled])
-
- return
- {children}
-
-}
-```
-
-The `typeof window !== 'undefined'` check prevents bundling preloaded modules for SSR, optimizing server bundle size and build speed.
diff --git a/.github/skills/vercel-react-best-practices/rules/client-event-listeners.md b/.github/skills/vercel-react-best-practices/rules/client-event-listeners.md
deleted file mode 100644
index aad4ae91..00000000
--- a/.github/skills/vercel-react-best-practices/rules/client-event-listeners.md
+++ /dev/null
@@ -1,74 +0,0 @@
----
-title: Deduplicate Global Event Listeners
-impact: LOW
-impactDescription: single listener for N components
-tags: client, swr, event-listeners, subscription
----
-
-## Deduplicate Global Event Listeners
-
-Use `useSWRSubscription()` to share global event listeners across component instances.
-
-**Incorrect (N instances = N listeners):**
-
-```tsx
-function useKeyboardShortcut(key: string, callback: () => void) {
- useEffect(() => {
- const handler = (e: KeyboardEvent) => {
- if (e.metaKey && e.key === key) {
- callback()
- }
- }
- window.addEventListener('keydown', handler)
- return () => window.removeEventListener('keydown', handler)
- }, [key, callback])
-}
-```
-
-When using the `useKeyboardShortcut` hook multiple times, each instance will register a new listener.
-
-**Correct (N instances = 1 listener):**
-
-```tsx
-import useSWRSubscription from 'swr/subscription'
-
-// Module-level Map to track callbacks per key
-const keyCallbacks = new Map void>>()
-
-function useKeyboardShortcut(key: string, callback: () => void) {
- // Register this callback in the Map
- useEffect(() => {
- if (!keyCallbacks.has(key)) {
- keyCallbacks.set(key, new Set())
- }
- keyCallbacks.get(key)!.add(callback)
-
- return () => {
- const set = keyCallbacks.get(key)
- if (set) {
- set.delete(callback)
- if (set.size === 0) {
- keyCallbacks.delete(key)
- }
- }
- }
- }, [key, callback])
-
- useSWRSubscription('global-keydown', () => {
- const handler = (e: KeyboardEvent) => {
- if (e.metaKey && keyCallbacks.has(e.key)) {
- keyCallbacks.get(e.key)!.forEach(cb => cb())
- }
- }
- window.addEventListener('keydown', handler)
- return () => window.removeEventListener('keydown', handler)
- })
-}
-
-function Profile() {
- // Multiple shortcuts will share the same listener
- useKeyboardShortcut('p', () => { /* ... */ })
- useKeyboardShortcut('k', () => { /* ... */ })
- // ...
-}
-```
diff --git a/.github/skills/vercel-react-best-practices/rules/client-swr-dedup.md b/.github/skills/vercel-react-best-practices/rules/client-swr-dedup.md
deleted file mode 100644
index 2a430f27..00000000
--- a/.github/skills/vercel-react-best-practices/rules/client-swr-dedup.md
+++ /dev/null
@@ -1,56 +0,0 @@
----
-title: Use SWR for Automatic Deduplication
-impact: MEDIUM-HIGH
-impactDescription: automatic deduplication
-tags: client, swr, deduplication, data-fetching
----
-
-## Use SWR for Automatic Deduplication
-
-SWR enables request deduplication, caching, and revalidation across component instances.
-
-**Incorrect (no deduplication, each instance fetches):**
-
-```tsx
-function UserList() {
- const [users, setUsers] = useState([])
- useEffect(() => {
- fetch('/api/users')
- .then(r => r.json())
- .then(setUsers)
- }, [])
-}
-```
-
-**Correct (multiple instances share one request):**
-
-```tsx
-import useSWR from 'swr'
-
-function UserList() {
- const { data: users } = useSWR('/api/users', fetcher)
-}
-```
-
-**For immutable data:**
-
-```tsx
-import { useImmutableSWR } from '@/lib/swr'
-
-function StaticContent() {
- const { data } = useImmutableSWR('/api/config', fetcher)
-}
-```
-
-**For mutations:**
-
-```tsx
-import { useSWRMutation } from 'swr/mutation'
-
-function UpdateButton() {
- const { trigger } = useSWRMutation('/api/user', updateUser)
- return trigger()}>Update
-}
-```
-
-Reference: [https://swr.vercel.app](https://swr.vercel.app)
diff --git a/.github/skills/vercel-react-best-practices/rules/js-batch-dom-css.md b/.github/skills/vercel-react-best-practices/rules/js-batch-dom-css.md
deleted file mode 100644
index 92a3b639..00000000
--- a/.github/skills/vercel-react-best-practices/rules/js-batch-dom-css.md
+++ /dev/null
@@ -1,82 +0,0 @@
----
-title: Batch DOM CSS Changes
-impact: MEDIUM
-impactDescription: reduces reflows/repaints
-tags: javascript, dom, css, performance, reflow
----
-
-## Batch DOM CSS Changes
-
-Avoid changing styles one property at a time. Group multiple CSS changes together via classes or `cssText` to minimize browser reflows.
-
-**Incorrect (multiple reflows):**
-
-```typescript
-function updateElementStyles(element: HTMLElement) {
- // Each line triggers a reflow
- element.style.width = '100px'
- element.style.height = '200px'
- element.style.backgroundColor = 'blue'
- element.style.border = '1px solid black'
-}
-```
-
-**Correct (add class - single reflow):**
-
-```typescript
-// CSS file
-.highlighted-box {
- width: 100px;
- height: 200px;
- background-color: blue;
- border: 1px solid black;
-}
-
-// JavaScript
-function updateElementStyles(element: HTMLElement) {
- element.classList.add('highlighted-box')
-}
-```
-
-**Correct (change cssText - single reflow):**
-
-```typescript
-function updateElementStyles(element: HTMLElement) {
- element.style.cssText = `
- width: 100px;
- height: 200px;
- background-color: blue;
- border: 1px solid black;
- `
-}
-```
-
-**React example:**
-
-```tsx
-// Incorrect: changing styles one by one
-function Box({ isHighlighted }: { isHighlighted: boolean }) {
- const ref = useRef(null)
-
- useEffect(() => {
- if (ref.current && isHighlighted) {
- ref.current.style.width = '100px'
- ref.current.style.height = '200px'
- ref.current.style.backgroundColor = 'blue'
- }
- }, [isHighlighted])
-
- return Content
-}
-
-// Correct: toggle class
-function Box({ isHighlighted }: { isHighlighted: boolean }) {
- return (
-
- Content
-
- )
-}
-```
-
-Prefer CSS classes over inline styles when possible. Classes are cached by the browser and provide better separation of concerns.
diff --git a/.github/skills/vercel-react-best-practices/rules/js-cache-function-results.md b/.github/skills/vercel-react-best-practices/rules/js-cache-function-results.md
deleted file mode 100644
index 180f8ac8..00000000
--- a/.github/skills/vercel-react-best-practices/rules/js-cache-function-results.md
+++ /dev/null
@@ -1,80 +0,0 @@
----
-title: Cache Repeated Function Calls
-impact: MEDIUM
-impactDescription: avoid redundant computation
-tags: javascript, cache, memoization, performance
----
-
-## Cache Repeated Function Calls
-
-Use a module-level Map to cache function results when the same function is called repeatedly with the same inputs during render.
-
-**Incorrect (redundant computation):**
-
-```typescript
-function ProjectList({ projects }: { projects: Project[] }) {
- return (
-
- {projects.map(project => {
- // slugify() called 100+ times for same project names
- const slug = slugify(project.name)
-
- return
- })}
-
()
-
-function cachedSlugify(text: string): string {
- if (slugifyCache.has(text)) {
- return slugifyCache.get(text)!
- }
- const result = slugify(text)
- slugifyCache.set(text, result)
- return result
-}
-
-function ProjectList({ projects }: { projects: Project[] }) {
- return (
-
- {projects.map(project => {
- // Computed only once per unique project name
- const slug = cachedSlugify(project.name)
-
- return
- })}
-
()
-
-function getLocalStorage(key: string) {
- if (!storageCache.has(key)) {
- storageCache.set(key, localStorage.getItem(key))
- }
- return storageCache.get(key)
-}
-
-function setLocalStorage(key: string, value: string) {
- localStorage.setItem(key, value)
- storageCache.set(key, value) // keep cache in sync
-}
-```
-
-Use a Map (not a hook) so it works everywhere: utilities, event handlers, not just React components.
-
-**Cookie caching:**
-
-```typescript
-let cookieCache: Record | null = null
-
-function getCookie(name: string) {
- if (!cookieCache) {
- cookieCache = Object.fromEntries(
- document.cookie.split('; ').map(c => c.split('='))
- )
- }
- return cookieCache[name]
-}
-```
-
-**Important (invalidate on external changes):**
-
-If storage can change externally (another tab, server-set cookies), invalidate cache:
-
-```typescript
-window.addEventListener('storage', (e) => {
- if (e.key) storageCache.delete(e.key)
-})
-
-document.addEventListener('visibilitychange', () => {
- if (document.visibilityState === 'visible') {
- storageCache.clear()
- }
-})
-```
diff --git a/.github/skills/vercel-react-best-practices/rules/js-combine-iterations.md b/.github/skills/vercel-react-best-practices/rules/js-combine-iterations.md
deleted file mode 100644
index 044d017e..00000000
--- a/.github/skills/vercel-react-best-practices/rules/js-combine-iterations.md
+++ /dev/null
@@ -1,32 +0,0 @@
----
-title: Combine Multiple Array Iterations
-impact: LOW-MEDIUM
-impactDescription: reduces iterations
-tags: javascript, arrays, loops, performance
----
-
-## Combine Multiple Array Iterations
-
-Multiple `.filter()` or `.map()` calls iterate the array multiple times. Combine into one loop.
-
-**Incorrect (3 iterations):**
-
-```typescript
-const admins = users.filter(u => u.isAdmin)
-const testers = users.filter(u => u.isTester)
-const inactive = users.filter(u => !u.isActive)
-```
-
-**Correct (1 iteration):**
-
-```typescript
-const admins: User[] = []
-const testers: User[] = []
-const inactive: User[] = []
-
-for (const user of users) {
- if (user.isAdmin) admins.push(user)
- if (user.isTester) testers.push(user)
- if (!user.isActive) inactive.push(user)
-}
-```
diff --git a/.github/skills/vercel-react-best-practices/rules/js-early-exit.md b/.github/skills/vercel-react-best-practices/rules/js-early-exit.md
deleted file mode 100644
index f46cb89c..00000000
--- a/.github/skills/vercel-react-best-practices/rules/js-early-exit.md
+++ /dev/null
@@ -1,50 +0,0 @@
----
-title: Early Return from Functions
-impact: LOW-MEDIUM
-impactDescription: avoids unnecessary computation
-tags: javascript, functions, optimization, early-return
----
-
-## Early Return from Functions
-
-Return early when result is determined to skip unnecessary processing.
-
-**Incorrect (processes all items even after finding answer):**
-
-```typescript
-function validateUsers(users: User[]) {
- let hasError = false
- let errorMessage = ''
-
- for (const user of users) {
- if (!user.email) {
- hasError = true
- errorMessage = 'Email required'
- }
- if (!user.name) {
- hasError = true
- errorMessage = 'Name required'
- }
- // Continues checking all users even after error found
- }
-
- return hasError ? { valid: false, error: errorMessage } : { valid: true }
-}
-```
-
-**Correct (returns immediately on first error):**
-
-```typescript
-function validateUsers(users: User[]) {
- for (const user of users) {
- if (!user.email) {
- return { valid: false, error: 'Email required' }
- }
- if (!user.name) {
- return { valid: false, error: 'Name required' }
- }
- }
-
- return { valid: true }
-}
-```
diff --git a/.github/skills/vercel-react-best-practices/rules/js-hoist-regexp.md b/.github/skills/vercel-react-best-practices/rules/js-hoist-regexp.md
deleted file mode 100644
index dae3fefd..00000000
--- a/.github/skills/vercel-react-best-practices/rules/js-hoist-regexp.md
+++ /dev/null
@@ -1,45 +0,0 @@
----
-title: Hoist RegExp Creation
-impact: LOW-MEDIUM
-impactDescription: avoids recreation
-tags: javascript, regexp, optimization, memoization
----
-
-## Hoist RegExp Creation
-
-Don't create RegExp inside render. Hoist to module scope or memoize with `useMemo()`.
-
-**Incorrect (new RegExp every render):**
-
-```tsx
-function Highlighter({ text, query }: Props) {
- const regex = new RegExp(`(${query})`, 'gi')
- const parts = text.split(regex)
- return <>{parts.map((part, i) => ...)}
-}
-```
-
-**Correct (memoize or hoist):**
-
-```tsx
-const EMAIL_REGEX = /^[^\s@]+@[^\s@]+\.[^\s@]+$/
-
-function Highlighter({ text, query }: Props) {
- const regex = useMemo(
- () => new RegExp(`(${escapeRegex(query)})`, 'gi'),
- [query]
- )
- const parts = text.split(regex)
- return <>{parts.map((part, i) => ...)}
-}
-```
-
-**Warning (global regex has mutable state):**
-
-Global regex (`/g`) has mutable `lastIndex` state:
-
-```typescript
-const regex = /foo/g
-regex.test('foo') // true, lastIndex = 3
-regex.test('foo') // false, lastIndex = 0
-```
diff --git a/.github/skills/vercel-react-best-practices/rules/js-index-maps.md b/.github/skills/vercel-react-best-practices/rules/js-index-maps.md
deleted file mode 100644
index 9d357a00..00000000
--- a/.github/skills/vercel-react-best-practices/rules/js-index-maps.md
+++ /dev/null
@@ -1,37 +0,0 @@
----
-title: Build Index Maps for Repeated Lookups
-impact: LOW-MEDIUM
-impactDescription: 1M ops to 2K ops
-tags: javascript, map, indexing, optimization, performance
----
-
-## Build Index Maps for Repeated Lookups
-
-Multiple `.find()` calls by the same key should use a Map.
-
-**Incorrect (O(n) per lookup):**
-
-```typescript
-function processOrders(orders: Order[], users: User[]) {
- return orders.map(order => ({
- ...order,
- user: users.find(u => u.id === order.userId)
- }))
-}
-```
-
-**Correct (O(1) per lookup):**
-
-```typescript
-function processOrders(orders: Order[], users: User[]) {
- const userById = new Map(users.map(u => [u.id, u]))
-
- return orders.map(order => ({
- ...order,
- user: userById.get(order.userId)
- }))
-}
-```
-
-Build map once (O(n)), then all lookups are O(1).
-For 1000 orders × 1000 users: 1M ops → 2K ops.
diff --git a/.github/skills/vercel-react-best-practices/rules/js-length-check-first.md b/.github/skills/vercel-react-best-practices/rules/js-length-check-first.md
deleted file mode 100644
index 6c38625f..00000000
--- a/.github/skills/vercel-react-best-practices/rules/js-length-check-first.md
+++ /dev/null
@@ -1,49 +0,0 @@
----
-title: Early Length Check for Array Comparisons
-impact: MEDIUM-HIGH
-impactDescription: avoids expensive operations when lengths differ
-tags: javascript, arrays, performance, optimization, comparison
----
-
-## Early Length Check for Array Comparisons
-
-When comparing arrays with expensive operations (sorting, deep equality, serialization), check lengths first. If lengths differ, the arrays cannot be equal.
-
-In real-world applications, this optimization is especially valuable when the comparison runs in hot paths (event handlers, render loops).
-
-**Incorrect (always runs expensive comparison):**
-
-```typescript
-function hasChanges(current: string[], original: string[]) {
- // Always sorts and joins, even when lengths differ
- return current.sort().join() !== original.sort().join()
-}
-```
-
-Two O(n log n) sorts run even when `current.length` is 5 and `original.length` is 100. There is also overhead of joining the arrays and comparing the strings.
-
-**Correct (O(1) length check first):**
-
-```typescript
-function hasChanges(current: string[], original: string[]) {
- // Early return if lengths differ
- if (current.length !== original.length) {
- return true
- }
- // Only sort/join when lengths match
- const currentSorted = current.toSorted()
- const originalSorted = original.toSorted()
- for (let i = 0; i < currentSorted.length; i++) {
- if (currentSorted[i] !== originalSorted[i]) {
- return true
- }
- }
- return false
-}
-```
-
-This new approach is more efficient because:
-- It avoids the overhead of sorting and joining the arrays when lengths differ
-- It avoids consuming memory for the joined strings (especially important for large arrays)
-- It avoids mutating the original arrays
-- It returns early when a difference is found
diff --git a/.github/skills/vercel-react-best-practices/rules/js-min-max-loop.md b/.github/skills/vercel-react-best-practices/rules/js-min-max-loop.md
deleted file mode 100644
index 02caec56..00000000
--- a/.github/skills/vercel-react-best-practices/rules/js-min-max-loop.md
+++ /dev/null
@@ -1,82 +0,0 @@
----
-title: Use Loop for Min/Max Instead of Sort
-impact: LOW
-impactDescription: O(n) instead of O(n log n)
-tags: javascript, arrays, performance, sorting, algorithms
----
-
-## Use Loop for Min/Max Instead of Sort
-
-Finding the smallest or largest element only requires a single pass through the array. Sorting is wasteful and slower.
-
-**Incorrect (O(n log n) - sort to find latest):**
-
-```typescript
-interface Project {
- id: string
- name: string
- updatedAt: number
-}
-
-function getLatestProject(projects: Project[]) {
- const sorted = [...projects].sort((a, b) => b.updatedAt - a.updatedAt)
- return sorted[0]
-}
-```
-
-Sorts the entire array just to find the maximum value.
-
-**Incorrect (O(n log n) - sort for oldest and newest):**
-
-```typescript
-function getOldestAndNewest(projects: Project[]) {
- const sorted = [...projects].sort((a, b) => a.updatedAt - b.updatedAt)
- return { oldest: sorted[0], newest: sorted[sorted.length - 1] }
-}
-```
-
-Still sorts unnecessarily when only min/max are needed.
-
-**Correct (O(n) - single loop):**
-
-```typescript
-function getLatestProject(projects: Project[]) {
- if (projects.length === 0) return null
-
- let latest = projects[0]
-
- for (let i = 1; i < projects.length; i++) {
- if (projects[i].updatedAt > latest.updatedAt) {
- latest = projects[i]
- }
- }
-
- return latest
-}
-
-function getOldestAndNewest(projects: Project[]) {
- if (projects.length === 0) return { oldest: null, newest: null }
-
- let oldest = projects[0]
- let newest = projects[0]
-
- for (let i = 1; i < projects.length; i++) {
- if (projects[i].updatedAt < oldest.updatedAt) oldest = projects[i]
- if (projects[i].updatedAt > newest.updatedAt) newest = projects[i]
- }
-
- return { oldest, newest }
-}
-```
-
-Single pass through the array, no copying, no sorting.
-
-**Alternative (Math.min/Math.max for small arrays):**
-
-```typescript
-const numbers = [5, 2, 8, 1, 9]
-const min = Math.min(...numbers)
-const max = Math.max(...numbers)
-```
-
-This works for small arrays but can be slower for very large arrays due to spread operator limitations. Use the loop approach for reliability.
diff --git a/.github/skills/vercel-react-best-practices/rules/js-set-map-lookups.md b/.github/skills/vercel-react-best-practices/rules/js-set-map-lookups.md
deleted file mode 100644
index 680a4892..00000000
--- a/.github/skills/vercel-react-best-practices/rules/js-set-map-lookups.md
+++ /dev/null
@@ -1,24 +0,0 @@
----
-title: Use Set/Map for O(1) Lookups
-impact: LOW-MEDIUM
-impactDescription: O(n) to O(1)
-tags: javascript, set, map, data-structures, performance
----
-
-## Use Set/Map for O(1) Lookups
-
-Convert arrays to Set/Map for repeated membership checks.
-
-**Incorrect (O(n) per check):**
-
-```typescript
-const allowedIds = ['a', 'b', 'c', ...]
-items.filter(item => allowedIds.includes(item.id))
-```
-
-**Correct (O(1) per check):**
-
-```typescript
-const allowedIds = new Set(['a', 'b', 'c', ...])
-items.filter(item => allowedIds.has(item.id))
-```
diff --git a/.github/skills/vercel-react-best-practices/rules/js-tosorted-immutable.md b/.github/skills/vercel-react-best-practices/rules/js-tosorted-immutable.md
deleted file mode 100644
index eae8b3f8..00000000
--- a/.github/skills/vercel-react-best-practices/rules/js-tosorted-immutable.md
+++ /dev/null
@@ -1,57 +0,0 @@
----
-title: Use toSorted() Instead of sort() for Immutability
-impact: MEDIUM-HIGH
-impactDescription: prevents mutation bugs in React state
-tags: javascript, arrays, immutability, react, state, mutation
----
-
-## Use toSorted() Instead of sort() for Immutability
-
-`.sort()` mutates the array in place, which can cause bugs with React state and props. Use `.toSorted()` to create a new sorted array without mutation.
-
-**Incorrect (mutates original array):**
-
-```typescript
-function UserList({ users }: { users: User[] }) {
- // Mutates the users prop array!
- const sorted = useMemo(
- () => users.sort((a, b) => a.name.localeCompare(b.name)),
- [users]
- )
- return {sorted.map(renderUser)}
-}
-```
-
-**Correct (creates new array):**
-
-```typescript
-function UserList({ users }: { users: User[] }) {
- // Creates new sorted array, original unchanged
- const sorted = useMemo(
- () => users.toSorted((a, b) => a.name.localeCompare(b.name)),
- [users]
- )
- return {sorted.map(renderUser)}
-}
-```
-
-**Why this matters in React:**
-
-1. Props/state mutations break React's immutability model - React expects props and state to be treated as read-only
-2. Causes stale closure bugs - Mutating arrays inside closures (callbacks, effects) can lead to unexpected behavior
-
-**Browser support (fallback for older browsers):**
-
-`.toSorted()` is available in all modern browsers (Chrome 110+, Safari 16+, Firefox 115+, Node.js 20+). For older environments, use spread operator:
-
-```typescript
-// Fallback for older browsers
-const sorted = [...items].sort((a, b) => a.value - b.value)
-```
-
-**Other immutable array methods:**
-
-- `.toSorted()` - immutable sort
-- `.toReversed()` - immutable reverse
-- `.toSpliced()` - immutable splice
-- `.with()` - immutable element replacement
diff --git a/.github/skills/vercel-react-best-practices/rules/rendering-activity.md b/.github/skills/vercel-react-best-practices/rules/rendering-activity.md
deleted file mode 100644
index c957a490..00000000
--- a/.github/skills/vercel-react-best-practices/rules/rendering-activity.md
+++ /dev/null
@@ -1,26 +0,0 @@
----
-title: Use Activity Component for Show/Hide
-impact: MEDIUM
-impactDescription: preserves state/DOM
-tags: rendering, activity, visibility, state-preservation
----
-
-## Use Activity Component for Show/Hide
-
-Use React's `` to preserve state/DOM for expensive components that frequently toggle visibility.
-
-**Usage:**
-
-```tsx
-import { Activity } from 'react'
-
-function Dropdown({ isOpen }: Props) {
- return (
-
-
- )
-}
-```
-
-Avoids expensive re-renders and state loss.
diff --git a/.github/skills/vercel-react-best-practices/rules/rendering-animate-svg-wrapper.md b/.github/skills/vercel-react-best-practices/rules/rendering-animate-svg-wrapper.md
deleted file mode 100644
index 646744cb..00000000
--- a/.github/skills/vercel-react-best-practices/rules/rendering-animate-svg-wrapper.md
+++ /dev/null
@@ -1,47 +0,0 @@
----
-title: Animate SVG Wrapper Instead of SVG Element
-impact: LOW
-impactDescription: enables hardware acceleration
-tags: rendering, svg, css, animation, performance
----
-
-## Animate SVG Wrapper Instead of SVG Element
-
-Many browsers don't have hardware acceleration for CSS3 animations on SVG elements. Wrap SVG in a `` and animate the wrapper instead.
-
-**Incorrect (animating SVG directly - no hardware acceleration):**
-
-```tsx
-function LoadingSpinner() {
- return (
-
-
- )
-}
-```
-
-**Correct (animating wrapper div - hardware accelerated):**
-
-```tsx
-function LoadingSpinner() {
- return (
-
-
-
-
- )
-}
-```
-
-This applies to all CSS transforms and transitions (`transform`, `opacity`, `translate`, `scale`, `rotate`). The wrapper div allows browsers to use GPU acceleration for smoother animations.
diff --git a/.github/skills/vercel-react-best-practices/rules/rendering-conditional-render.md b/.github/skills/vercel-react-best-practices/rules/rendering-conditional-render.md
deleted file mode 100644
index 7e866f58..00000000
--- a/.github/skills/vercel-react-best-practices/rules/rendering-conditional-render.md
+++ /dev/null
@@ -1,40 +0,0 @@
----
-title: Use Explicit Conditional Rendering
-impact: LOW
-impactDescription: prevents rendering 0 or NaN
-tags: rendering, conditional, jsx, falsy-values
----
-
-## Use Explicit Conditional Rendering
-
-Use explicit ternary operators (`? :`) instead of `&&` for conditional rendering when the condition can be `0`, `NaN`, or other falsy values that render.
-
-**Incorrect (renders "0" when count is 0):**
-
-```tsx
-function Badge({ count }: { count: number }) {
- return (
-
- {count && {count} }
-
- )
-}
-
-// When count = 0, renders:
0
-// When count = 5, renders:
5
-```
-
-**Correct (renders nothing when count is 0):**
-
-```tsx
-function Badge({ count }: { count: number }) {
- return (
-
- {count > 0 ? {count} : null}
-
- )
-}
-
-// When count = 0, renders:
-// When count = 5, renders:
5
-```
diff --git a/.github/skills/vercel-react-best-practices/rules/rendering-content-visibility.md b/.github/skills/vercel-react-best-practices/rules/rendering-content-visibility.md
deleted file mode 100644
index aa665636..00000000
--- a/.github/skills/vercel-react-best-practices/rules/rendering-content-visibility.md
+++ /dev/null
@@ -1,38 +0,0 @@
----
-title: CSS content-visibility for Long Lists
-impact: HIGH
-impactDescription: faster initial render
-tags: rendering, css, content-visibility, long-lists
----
-
-## CSS content-visibility for Long Lists
-
-Apply `content-visibility: auto` to defer off-screen rendering.
-
-**CSS:**
-
-```css
-.message-item {
- content-visibility: auto;
- contain-intrinsic-size: 0 80px;
-}
-```
-
-**Example:**
-
-```tsx
-function MessageList({ messages }: { messages: Message[] }) {
- return (
-
- {messages.map(msg => (
-
- ))}
-
- )
-}
-```
-
-For 1000 messages, browser skips layout/paint for ~990 off-screen items (10× faster initial render).
diff --git a/.github/skills/vercel-react-best-practices/rules/rendering-hoist-jsx.md b/.github/skills/vercel-react-best-practices/rules/rendering-hoist-jsx.md
deleted file mode 100644
index 32d2f3fc..00000000
--- a/.github/skills/vercel-react-best-practices/rules/rendering-hoist-jsx.md
+++ /dev/null
@@ -1,46 +0,0 @@
----
-title: Hoist Static JSX Elements
-impact: LOW
-impactDescription: avoids re-creation
-tags: rendering, jsx, static, optimization
----
-
-## Hoist Static JSX Elements
-
-Extract static JSX outside components to avoid re-creation.
-
-**Incorrect (recreates element every render):**
-
-```tsx
-function LoadingSkeleton() {
- return
-}
-
-function Container() {
- return (
-
- {loading &&
- )
-}
-```
-
-**Correct (reuses same element):**
-
-```tsx
-const loadingSkeleton = (
-
-)
-
-function Container() {
- return (
-
- {loading && loadingSkeleton}
-
- )
-}
-```
-
-This is especially helpful for large and static SVG nodes, which can be expensive to recreate on every render.
-
-**Note:** If your project has [React Compiler](https://react.dev/learn/react-compiler) enabled, the compiler automatically hoists static JSX elements and optimizes component re-renders, making manual hoisting unnecessary.
diff --git a/.github/skills/vercel-react-best-practices/rules/rendering-hydration-no-flicker.md b/.github/skills/vercel-react-best-practices/rules/rendering-hydration-no-flicker.md
deleted file mode 100644
index 5cf0e79b..00000000
--- a/.github/skills/vercel-react-best-practices/rules/rendering-hydration-no-flicker.md
+++ /dev/null
@@ -1,82 +0,0 @@
----
-title: Prevent Hydration Mismatch Without Flickering
-impact: MEDIUM
-impactDescription: avoids visual flicker and hydration errors
-tags: rendering, ssr, hydration, localStorage, flicker
----
-
-## Prevent Hydration Mismatch Without Flickering
-
-When rendering content that depends on client-side storage (localStorage, cookies), avoid both SSR breakage and post-hydration flickering by injecting a synchronous script that updates the DOM before React hydrates.
-
-**Incorrect (breaks SSR):**
-
-```tsx
-function ThemeWrapper({ children }: { children: ReactNode }) {
- // localStorage is not available on server - throws error
- const theme = localStorage.getItem('theme') || 'light'
-
- return (
-
- {children}
-
- )
-}
-```
-
-Server-side rendering will fail because `localStorage` is undefined.
-
-**Incorrect (visual flickering):**
-
-```tsx
-function ThemeWrapper({ children }: { children: ReactNode }) {
- const [theme, setTheme] = useState('light')
-
- useEffect(() => {
- // Runs after hydration - causes visible flash
- const stored = localStorage.getItem('theme')
- if (stored) {
- setTheme(stored)
- }
- }, [])
-
- return (
-
- {children}
-
- )
-}
-```
-
-Component first renders with default value (`light`), then updates after hydration, causing a visible flash of incorrect content.
-
-**Correct (no flicker, no hydration mismatch):**
-
-```tsx
-function ThemeWrapper({ children }: { children: ReactNode }) {
- return (
- <>
-
- {children}
-
-
-
- )
-}
-```
-
-The inline script executes synchronously before showing the element, ensuring the DOM already has the correct value. No flickering, no hydration mismatch.
-
-This pattern is especially useful for theme toggles, user preferences, authentication states, and any client-only data that should render immediately without flashing default values.
diff --git a/.github/skills/vercel-react-best-practices/rules/rendering-svg-precision.md b/.github/skills/vercel-react-best-practices/rules/rendering-svg-precision.md
deleted file mode 100644
index 6d771286..00000000
--- a/.github/skills/vercel-react-best-practices/rules/rendering-svg-precision.md
+++ /dev/null
@@ -1,28 +0,0 @@
----
-title: Optimize SVG Precision
-impact: LOW
-impactDescription: reduces file size
-tags: rendering, svg, optimization, svgo
----
-
-## Optimize SVG Precision
-
-Reduce SVG coordinate precision to decrease file size. The optimal precision depends on the viewBox size, but in general reducing precision should be considered.
-
-**Incorrect (excessive precision):**
-
-```svg
-
-```
-
-**Correct (1 decimal place):**
-
-```svg
-
-```
-
-**Automate with SVGO:**
-
-```bash
-npx svgo --precision=1 --multipass icon.svg
-```
diff --git a/.github/skills/vercel-react-best-practices/rules/rerender-defer-reads.md b/.github/skills/vercel-react-best-practices/rules/rerender-defer-reads.md
deleted file mode 100644
index e867c95f..00000000
--- a/.github/skills/vercel-react-best-practices/rules/rerender-defer-reads.md
+++ /dev/null
@@ -1,39 +0,0 @@
----
-title: Defer State Reads to Usage Point
-impact: MEDIUM
-impactDescription: avoids unnecessary subscriptions
-tags: rerender, searchParams, localStorage, optimization
----
-
-## Defer State Reads to Usage Point
-
-Don't subscribe to dynamic state (searchParams, localStorage) if you only read it inside callbacks.
-
-**Incorrect (subscribes to all searchParams changes):**
-
-```tsx
-function ShareButton({ chatId }: { chatId: string }) {
- const searchParams = useSearchParams()
-
- const handleShare = () => {
- const ref = searchParams.get('ref')
- shareChat(chatId, { ref })
- }
-
- return
Share
-}
-```
-
-**Correct (reads on demand, no subscription):**
-
-```tsx
-function ShareButton({ chatId }: { chatId: string }) {
- const handleShare = () => {
- const params = new URLSearchParams(window.location.search)
- const ref = params.get('ref')
- shareChat(chatId, { ref })
- }
-
- return
Share
-}
-```
diff --git a/.github/skills/vercel-react-best-practices/rules/rerender-dependencies.md b/.github/skills/vercel-react-best-practices/rules/rerender-dependencies.md
deleted file mode 100644
index 47a4d926..00000000
--- a/.github/skills/vercel-react-best-practices/rules/rerender-dependencies.md
+++ /dev/null
@@ -1,45 +0,0 @@
----
-title: Narrow Effect Dependencies
-impact: LOW
-impactDescription: minimizes effect re-runs
-tags: rerender, useEffect, dependencies, optimization
----
-
-## Narrow Effect Dependencies
-
-Specify primitive dependencies instead of objects to minimize effect re-runs.
-
-**Incorrect (re-runs on any user field change):**
-
-```tsx
-useEffect(() => {
- console.log(user.id)
-}, [user])
-```
-
-**Correct (re-runs only when id changes):**
-
-```tsx
-useEffect(() => {
- console.log(user.id)
-}, [user.id])
-```
-
-**For derived state, compute outside effect:**
-
-```tsx
-// Incorrect: runs on width=767, 766, 765...
-useEffect(() => {
- if (width < 768) {
- enableMobileMode()
- }
-}, [width])
-
-// Correct: runs only on boolean transition
-const isMobile = width < 768
-useEffect(() => {
- if (isMobile) {
- enableMobileMode()
- }
-}, [isMobile])
-```
diff --git a/.github/skills/vercel-react-best-practices/rules/rerender-derived-state.md b/.github/skills/vercel-react-best-practices/rules/rerender-derived-state.md
deleted file mode 100644
index a15177ca..00000000
--- a/.github/skills/vercel-react-best-practices/rules/rerender-derived-state.md
+++ /dev/null
@@ -1,29 +0,0 @@
----
-title: Subscribe to Derived State
-impact: MEDIUM
-impactDescription: reduces re-render frequency
-tags: rerender, derived-state, media-query, optimization
----
-
-## Subscribe to Derived State
-
-Subscribe to derived boolean state instead of continuous values to reduce re-render frequency.
-
-**Incorrect (re-renders on every pixel change):**
-
-```tsx
-function Sidebar() {
- const width = useWindowWidth() // updates continuously
- const isMobile = width < 768
- return
-}
-```
-
-**Correct (re-renders only when boolean changes):**
-
-```tsx
-function Sidebar() {
- const isMobile = useMediaQuery('(max-width: 767px)')
- return
-}
-```
diff --git a/.github/skills/vercel-react-best-practices/rules/rerender-functional-setstate.md b/.github/skills/vercel-react-best-practices/rules/rerender-functional-setstate.md
deleted file mode 100644
index b004ef45..00000000
--- a/.github/skills/vercel-react-best-practices/rules/rerender-functional-setstate.md
+++ /dev/null
@@ -1,74 +0,0 @@
----
-title: Use Functional setState Updates
-impact: MEDIUM
-impactDescription: prevents stale closures and unnecessary callback recreations
-tags: react, hooks, useState, useCallback, callbacks, closures
----
-
-## Use Functional setState Updates
-
-When updating state based on the current state value, use the functional update form of setState instead of directly referencing the state variable. This prevents stale closures, eliminates unnecessary dependencies, and creates stable callback references.
-
-**Incorrect (requires state as dependency):**
-
-```tsx
-function TodoList() {
- const [items, setItems] = useState(initialItems)
-
- // Callback must depend on items, recreated on every items change
- const addItems = useCallback((newItems: Item[]) => {
- setItems([...items, ...newItems])
- }, [items]) // ❌ items dependency causes recreations
-
- // Risk of stale closure if dependency is forgotten
- const removeItem = useCallback((id: string) => {
- setItems(items.filter(item => item.id !== id))
- }, []) // ❌ Missing items dependency - will use stale items!
-
- return {avatar}
-}
-```
-
-**Correct (skips computation when loading):**
-
-```tsx
-const UserAvatar = memo(function UserAvatar({ user }: { user: User }) {
- const id = useMemo(() => computeAvatarId(user), [user])
- return
-
- )
-}
-```
-
-**Note:** If your project has [React Compiler](https://react.dev/learn/react-compiler) enabled, manual memoization with `memo()` and `useMemo()` is not necessary. The compiler automatically optimizes re-renders.
diff --git a/.github/skills/vercel-react-best-practices/rules/rerender-transitions.md b/.github/skills/vercel-react-best-practices/rules/rerender-transitions.md
deleted file mode 100644
index d99f43f7..00000000
--- a/.github/skills/vercel-react-best-practices/rules/rerender-transitions.md
+++ /dev/null
@@ -1,40 +0,0 @@
----
-title: Use Transitions for Non-Urgent Updates
-impact: MEDIUM
-impactDescription: maintains UI responsiveness
-tags: rerender, transitions, startTransition, performance
----
-
-## Use Transitions for Non-Urgent Updates
-
-Mark frequent, non-urgent state updates as transitions to maintain UI responsiveness.
-
-**Incorrect (blocks UI on every scroll):**
-
-```tsx
-function ScrollTracker() {
- const [scrollY, setScrollY] = useState(0)
- useEffect(() => {
- const handler = () => setScrollY(window.scrollY)
- window.addEventListener('scroll', handler, { passive: true })
- return () => window.removeEventListener('scroll', handler)
- }, [])
-}
-```
-
-**Correct (non-blocking updates):**
-
-```tsx
-import { startTransition } from 'react'
-
-function ScrollTracker() {
- const [scrollY, setScrollY] = useState(0)
- useEffect(() => {
- const handler = () => {
- startTransition(() => setScrollY(window.scrollY))
- }
- window.addEventListener('scroll', handler, { passive: true })
- return () => window.removeEventListener('scroll', handler)
- }, [])
-}
-```
diff --git a/.github/skills/vercel-react-best-practices/rules/server-after-nonblocking.md b/.github/skills/vercel-react-best-practices/rules/server-after-nonblocking.md
deleted file mode 100644
index e8f5b260..00000000
--- a/.github/skills/vercel-react-best-practices/rules/server-after-nonblocking.md
+++ /dev/null
@@ -1,73 +0,0 @@
----
-title: Use after() for Non-Blocking Operations
-impact: MEDIUM
-impactDescription: faster response times
-tags: server, async, logging, analytics, side-effects
----
-
-## Use after() for Non-Blocking Operations
-
-Use Next.js's `after()` to schedule work that should execute after a response is sent. This prevents logging, analytics, and other side effects from blocking the response.
-
-**Incorrect (blocks response):**
-
-```tsx
-import { logUserAction } from '@/app/utils'
-
-export async function POST(request: Request) {
- // Perform mutation
- await updateDatabase(request)
-
- // Logging blocks the response
- const userAgent = request.headers.get('user-agent') || 'unknown'
- await logUserAction({ userAgent })
-
- return new Response(JSON.stringify({ status: 'success' }), {
- status: 200,
- headers: { 'Content-Type': 'application/json' }
- })
-}
-```
-
-**Correct (non-blocking):**
-
-```tsx
-import { after } from 'next/server'
-import { headers, cookies } from 'next/headers'
-import { logUserAction } from '@/app/utils'
-
-export async function POST(request: Request) {
- // Perform mutation
- await updateDatabase(request)
-
- // Log after response is sent
- after(async () => {
- const userAgent = (await headers()).get('user-agent') || 'unknown'
- const sessionCookie = (await cookies()).get('session-id')?.value || 'anonymous'
-
- logUserAction({ sessionCookie, userAgent })
- })
-
- return new Response(JSON.stringify({ status: 'success' }), {
- status: 200,
- headers: { 'Content-Type': 'application/json' }
- })
-}
-```
-
-The response is sent immediately while logging happens in the background.
-
-**Common use cases:**
-
-- Analytics tracking
-- Audit logging
-- Sending notifications
-- Cache invalidation
-- Cleanup tasks
-
-**Important notes:**
-
-- `after()` runs even if the response fails or redirects
-- Works in Server Actions, Route Handlers, and Server Components
-
-Reference: [https://nextjs.org/docs/app/api-reference/functions/after](https://nextjs.org/docs/app/api-reference/functions/after)
diff --git a/.github/skills/vercel-react-best-practices/rules/server-cache-lru.md b/.github/skills/vercel-react-best-practices/rules/server-cache-lru.md
deleted file mode 100644
index ef6938aa..00000000
--- a/.github/skills/vercel-react-best-practices/rules/server-cache-lru.md
+++ /dev/null
@@ -1,41 +0,0 @@
----
-title: Cross-Request LRU Caching
-impact: HIGH
-impactDescription: caches across requests
-tags: server, cache, lru, cross-request
----
-
-## Cross-Request LRU Caching
-
-`React.cache()` only works within one request. For data shared across sequential requests (user clicks button A then button B), use an LRU cache.
-
-**Implementation:**
-
-```typescript
-import { LRUCache } from 'lru-cache'
-
-const cache = new LRUCache({
- max: 1000,
- ttl: 5 * 60 * 1000 // 5 minutes
-})
-
-export async function getUser(id: string) {
- const cached = cache.get(id)
- if (cached) return cached
-
- const user = await db.user.findUnique({ where: { id } })
- cache.set(id, user)
- return user
-}
-
-// Request 1: DB query, result cached
-// Request 2: cache hit, no DB query
-```
-
-Use when sequential user actions hit multiple endpoints needing the same data within seconds.
-
-**With Vercel's [Fluid Compute](https://vercel.com/docs/fluid-compute):** LRU caching is especially effective because multiple concurrent requests can share the same function instance and cache. This means the cache persists across requests without needing external storage like Redis.
-
-**In traditional serverless:** Each invocation runs in isolation, so consider Redis for cross-process caching.
-
-Reference: [https://github.com/isaacs/node-lru-cache](https://github.com/isaacs/node-lru-cache)
diff --git a/.github/skills/vercel-react-best-practices/rules/server-cache-react.md b/.github/skills/vercel-react-best-practices/rules/server-cache-react.md
deleted file mode 100644
index fa49e0e8..00000000
--- a/.github/skills/vercel-react-best-practices/rules/server-cache-react.md
+++ /dev/null
@@ -1,26 +0,0 @@
----
-title: Per-Request Deduplication with React.cache()
-impact: MEDIUM
-impactDescription: deduplicates within request
-tags: server, cache, react-cache, deduplication
----
-
-## Per-Request Deduplication with React.cache()
-
-Use `React.cache()` for server-side request deduplication. Authentication and database queries benefit most.
-
-**Usage:**
-
-```typescript
-import { cache } from 'react'
-
-export const getCurrentUser = cache(async () => {
- const session = await auth()
- if (!session?.user?.id) return null
- return await db.user.findUnique({
- where: { id: session.user.id }
- })
-})
-```
-
-Within a single request, multiple calls to `getCurrentUser()` execute the query only once.
diff --git a/.github/skills/vercel-react-best-practices/rules/server-parallel-fetching.md b/.github/skills/vercel-react-best-practices/rules/server-parallel-fetching.md
deleted file mode 100644
index 5261f084..00000000
--- a/.github/skills/vercel-react-best-practices/rules/server-parallel-fetching.md
+++ /dev/null
@@ -1,79 +0,0 @@
----
-title: Parallel Data Fetching with Component Composition
-impact: CRITICAL
-impactDescription: eliminates server-side waterfalls
-tags: server, rsc, parallel-fetching, composition
----
-
-## Parallel Data Fetching with Component Composition
-
-React Server Components execute sequentially within a tree. Restructure with composition to parallelize data fetching.
-
-**Incorrect (Sidebar waits for Page's fetch to complete):**
-
-```tsx
-export default async function Page() {
- const header = await fetchHeader()
- return (
-
- )
-}
-
-async function Sidebar() {
- const items = await fetchSidebarItems()
- return {items.map(renderItem)}
-}
-```
-
-**Correct (both fetch simultaneously):**
-
-```tsx
-async function Header() {
- const data = await fetchHeader()
- return {data}
-}
-
-async function Sidebar() {
- const items = await fetchSidebarItems()
- return {items.map(renderItem)}
-}
-
-export default function Page() {
- return (
-
-
-
- )
-}
-```
-
-**Alternative with children prop:**
-
-```tsx
-async function Layout({ children }: { children: ReactNode }) {
- const header = await fetchHeader()
- return (
-
-
{header}
- {children}
-
{items.map(renderItem)}
-}
-
-export default function Page() {
- return (
-
-
- )
-}
-```
diff --git a/.github/skills/vercel-react-best-practices/rules/server-serialization.md b/.github/skills/vercel-react-best-practices/rules/server-serialization.md
deleted file mode 100644
index 39c5c416..00000000
--- a/.github/skills/vercel-react-best-practices/rules/server-serialization.md
+++ /dev/null
@@ -1,38 +0,0 @@
----
-title: Minimize Serialization at RSC Boundaries
-impact: HIGH
-impactDescription: reduces data transfer size
-tags: server, rsc, serialization, props
----
-
-## Minimize Serialization at RSC Boundaries
-
-The React Server/Client boundary serializes all object properties into strings and embeds them in the HTML response and subsequent RSC requests. This serialized data directly impacts page weight and load time, so **size matters a lot**. Only pass fields that the client actually uses.
-
-**Incorrect (serializes all 50 fields):**
-
-```tsx
-async function Page() {
- const user = await fetchUser() // 50 fields
- return {user.name}
// uses 1 field
-}
-```
-
-**Correct (serializes only 1 field):**
-
-```tsx
-async function Page() {
- const user = await fetchUser()
- return {name}
-}
-```
diff --git a/.github/skills/web-design-guidelines/SKILL.md b/.github/skills/web-design-guidelines/SKILL.md
deleted file mode 100644
index 83b34c20..00000000
--- a/.github/skills/web-design-guidelines/SKILL.md
+++ /dev/null
@@ -1,36 +0,0 @@
----
-name: web-design-guidelines
-description: Review UI code for Web Interface Guidelines compliance. Use when asked to "review my UI", "check accessibility", "audit design", "review UX", or "check my site against best practices".
-argument-hint:
----
-
-# Web Interface Guidelines
-
-Review files for compliance with Web Interface Guidelines.
-
-## How It Works
-
-1. Fetch the latest guidelines from the source URL below
-2. Read the specified files (or prompt user for files/pattern)
-3. Check against all rules in the fetched guidelines
-4. Output findings in the terse `file:line` format
-
-## Guidelines Source
-
-Fetch fresh guidelines before each review:
-
-```
-https://raw.githubusercontent.com/vercel-labs/web-interface-guidelines/main/command.md
-```
-
-Use WebFetch to retrieve the latest rules. The fetched content contains all the rules and output format instructions.
-
-## Usage
-
-When a user provides a file or pattern argument:
-1. Fetch guidelines from the source URL above
-2. Read the specified files
-3. Apply all rules from the fetched guidelines
-4. Output findings using the format specified in the guidelines
-
-If no files specified, ask the user which files to review.
diff --git a/next.config.ts b/next.config.ts
index 9fb6e077..2a3b5299 100644
--- a/next.config.ts
+++ b/next.config.ts
@@ -5,11 +5,6 @@ const nextConfig: NextConfig = {
reactStrictMode: false, // BlockNote is not yet compatible with React 19 StrictMode
// Transpile git-installed packages to ensure proper module resolution
transpilePackages: ["react-grid-layout"],
- // Optimize barrel file imports - reduces import cost from 200-800ms to near-zero
- // Automatically transforms barrel imports to direct imports at build time
- experimental: {
- optimizePackageImports: ["lucide-react"],
- },
images: {
remotePatterns: [
{
diff --git a/src/app/api/workspaces/[id]/events/route.ts b/src/app/api/workspaces/[id]/events/route.ts
index d1e04874..3f148ab9 100644
--- a/src/app/api/workspaces/[id]/events/route.ts
+++ b/src/app/api/workspaces/[id]/events/route.ts
@@ -228,24 +228,13 @@ export async function POST(
let id: string | undefined;
try {
- // Start independent operations in parallel (per async-parallel rule)
- const paramsPromise = params;
- const headersPromise = headers();
- const bodyPromise = request.json();
-
- const paramsResolved = await paramsPromise;
+ const paramsResolved = await params;
id = paramsResolved.id;
const authStart = Date.now();
- const sessionPromise = auth.api.getSession({
- headers: await headersPromise,
+ const session = await auth.api.getSession({
+ headers: await headers(),
});
-
- const bodyStart = Date.now();
- const body = await bodyPromise;
- timings.bodyParse = Date.now() - bodyStart;
-
- const session = await sessionPromise;
timings.auth = Date.now() - authStart;
if (!session) {
@@ -253,6 +242,10 @@ export async function POST(
}
const userId = session.user.id;
+
+ const bodyStart = Date.now();
+ const body = await request.json();
+ timings.bodyParse = Date.now() - bodyStart;
const { event, baseVersion } = body;
if (!event || baseVersion === undefined || isNaN(baseVersion)) {
diff --git a/src/app/api/workspaces/[id]/route.ts b/src/app/api/workspaces/[id]/route.ts
index c3228247..9a3f475f 100644
--- a/src/app/api/workspaces/[id]/route.ts
+++ b/src/app/api/workspaces/[id]/route.ts
@@ -15,24 +15,19 @@ export async function GET(
{ params }: { params: Promise<{ id: string }> }
) {
try {
- // Start independent operations in parallel (per async-parallel rule)
- const paramsPromise = params;
- const headersPromise = headers();
-
- const { id } = await paramsPromise;
- const sessionPromise = auth.api.getSession({
- headers: await headersPromise,
+ const { id } = await params;
+ const session = await auth.api.getSession({
+ headers: await headers(),
});
// Allow anonymous users
- const session = await sessionPromise;
if (!session) {
return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
}
const userId = session.user.id;
- // Get workspace - can run in parallel with session check since we need both
+ // Get workspace
const workspace = await db
.select()
.from(workspaces)
@@ -78,25 +73,19 @@ export async function PATCH(
{ params }: { params: Promise<{ id: string }> }
) {
try {
- // Start independent operations in parallel (per async-parallel rule)
- const paramsPromise = params;
- const headersPromise = headers();
- const bodyPromise = request.json();
-
- const { id } = await paramsPromise;
- const sessionPromise = auth.api.getSession({
- headers: await headersPromise,
+ const { id } = await params;
+ const session = await auth.api.getSession({
+ headers: await headers(),
});
// Allow anonymous users
- const session = await sessionPromise;
if (!session) {
return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
}
const userId = session.user.id;
- const body = await bodyPromise;
+ const body = await request.json();
const { name, description, is_public, icon, color } = body;
// Check ownership
@@ -151,17 +140,12 @@ export async function DELETE(
{ params }: { params: Promise<{ id: string }> }
) {
try {
- // Start independent operations in parallel (per async-parallel rule)
- const paramsPromise = params;
- const headersPromise = headers();
-
- const { id } = await paramsPromise;
- const sessionPromise = auth.api.getSession({
- headers: await headersPromise,
+ const { id } = await params;
+ const session = await auth.api.getSession({
+ headers: await headers(),
});
// Allow anonymous users
- const session = await sessionPromise;
if (!session) {
return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
}
diff --git a/src/app/api/workspaces/slug/[slug]/route.ts b/src/app/api/workspaces/slug/[slug]/route.ts
index 39fb6f97..19601ff2 100644
--- a/src/app/api/workspaces/slug/[slug]/route.ts
+++ b/src/app/api/workspaces/slug/[slug]/route.ts
@@ -15,16 +15,11 @@ export async function GET(
{ params }: { params: Promise<{ slug: string }> }
) {
try {
- // Start independent operations in parallel (per async-parallel rule)
- const paramsPromise = params;
- const headersPromise = headers();
-
- const { slug } = await paramsPromise;
- const sessionPromise = auth.api.getSession({
- headers: await headersPromise,
+ const { slug } = await params;
+ const session = await auth.api.getSession({
+ headers: await headers(),
});
- const session = await sessionPromise;
if (!session) {
return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
}
diff --git a/src/components/landing/FourWays.tsx b/src/components/landing/FourWays.tsx
index a9a5de21..2c3949f4 100644
--- a/src/components/landing/FourWays.tsx
+++ b/src/components/landing/FourWays.tsx
@@ -321,6 +321,7 @@ export function FourWays() {
? { objectPosition: "center top" }
: undefined
}
+ unoptimized
/>