)
}
// Examples:
// en: "Monday, October 22, 2025"
// es: "lunes, 22 de octubre de 2025"
// ja: "2025年10月22日月曜日"
```
---
## Number and Currency Formatting
```typescript
'use client'
import { useFormatter } from 'next-intl'
export function FormattedNumber({ value }: { value: number }) {
const format = useFormatter()
return (
}
// count = 0: "No items"
// count = 1: "1 item"
// count = 5: "5 items"
```
---
## RTL (Right-to-Left) Support
```typescript
// app/[locale]/layout.tsx
import { useLocale } from 'next-intl'
const rtlLanguages = ['ar', 'he', 'fa']
export default function LocaleLayout({ children }) {
const locale = useLocale()
const isRTL = rtlLanguages.includes(locale)
return (
{children}
)
}
```
**RTL CSS:**
```css
/* Automatically flips for RTL */
.container {
margin-inline-start: 1rem; /* Use logical properties */
padding-inline-end: 1rem;
}
/* Manual RTL handling */
[dir='rtl'] .menu {
left: auto;
right: 0;
}
```
---
## Language Detection
```typescript
// lib/detect-locale.ts
export function detectUserLocale(): string {
// 1. Check URL parameter
const urlParams = new URLSearchParams(window.location.search)
const urlLocale = urlParams.get('lang')
if (urlLocale) return urlLocale
// 2. Check localStorage
const savedLocale = localStorage.getItem('preferredLocale')
if (savedLocale) return savedLocale
// 3. Check browser language
const browserLocale = navigator.language.split('-')[0]
return browserLocale
// 4. Default
return 'en'
}
```
---
## Translation with Variables
```json
// messages/en.json
{
"welcome": "Welcome, {name}!",
"itemsInCart": "You have {count} {count, plural, one {item} other {items}} in your cart",
"priceDisplay": "Price: {price, number, ::currency/USD}"
}
```
```typescript
'use client'
import { useTranslations } from 'next-intl'
export function Greeting({ userName }: { userName: string }) {
const t = useTranslations()
return (
{t('welcome', { name: userName })}
{t('itemsInCart', { count: 3 })}
{t('priceDisplay', { price: 49.99 })}
)
}
// Output:
// "Welcome, John!"
// "You have 3 items in your cart"
// "Price: $49.99"
```
---
## Locale-Specific Content
```typescript
// app/[locale]/page.tsx
import { useLocale } from 'next-intl'
export default function HomePage() {
const locale = useLocale()
const content = {
en: {
hero: 'Build amazing apps',
description: 'The best platform for developers'
},
es: {
hero: 'Crea aplicaciones increíbles',
description: 'La mejor plataforma para desarrolladores'
},
ja: {
hero: '素晴らしいアプリを作成',
description: '開発者のための最高のプラットフォーム'
}
}
return (
{content[locale].hero}
{content[locale].description}
)
}
```
---
## Translation Management
### Using Translation Service (Lokalise, Crowdin)
```typescript
// scripts/sync-translations.ts
async function syncTranslations() {
// Download translations from service
const response = await fetch('https://api.lokalise.com/api2/projects/PROJECT_ID/files/download', {
headers: {
'X-Api-Token': process.env.LOKALISE_API_KEY!
}
})
const data = await response.json()
// Save to messages folder
await fs.writeFile('./messages/en.json', JSON.stringify(data.en, null, 2))
console.log('Translations synced!')
}
```
---
## Missing Translation Handling
```typescript
// i18n/request.ts
import { getRequestConfig } from 'next-intl/server'
export default getRequestConfig(async ({ locale }) => ({
messages: (await import(`../messages/${locale}.json`)).default,
onError: error => {
console.error('Translation error:', error)
},
getMessageFallback: ({ namespace, key, error }) => {
return `${namespace}.${key}` // Show key if translation missing
}
}))
```
---
## SEO for Multilingual Sites
```typescript
// app/[locale]/layout.tsx
import { useLocale } from 'next-intl'
export async function generateMetadata({ params: { locale } }) {
const t = await useTranslations('metadata')
return {
title: t('title'),
description: t('description'),
alternates: {
canonical: `/${locale}`,
languages: {
en: '/en',
es: '/es',
fr: '/fr',
de: '/de',
ja: '/ja'
}
}
}
}
```
**HTML Output:**
```html
```
---
## When to Use Me
**Perfect for:**
- Building multilingual applications
- International product launches
- Global SaaS platforms
- E-commerce in multiple countries
- Content management systems
**I'll help you:**
- Set up i18n infrastructure
- Manage translations
- Format dates, numbers, currencies
- Handle RTL languages
- Optimize for SEO
## What I'll Create
```
🌍 Multi-Language Support
📅 Date/Time Formatting
💰 Currency Formatting
🔄 Language Switching
📝 Translation Management
🌐 RTL Support
```
Let's make your app globally accessible!
---
Source attribution: daffy0208
Original project: https://github.com/daffy0208/ai-dev-standards/blob/32c3241e48f9fe2c3de611ad9168503ea41f28fd/skills/localization-engineer/SKILL.md
License: MIT
License information: https://opensource.org/license/mit
Original upstream instructions; downloaded from Dave AI.
## Upstream license notice
MIT License
Copyright (c) 2025 AI Dev Standards Contributors
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
# Dave AI resource metadata
Creator / publisher: daffy0208
Original project: https://github.com/daffy0208/ai-dev-standards/blob/32c3241e48f9fe2c3de611ad9168503ea41f28fd/skills/localization-engineer/SKILL.md
Attribution basis: Recovered original package and original project license at a pinned revision
Fields of work: Content & Media, Design, Development & Engineering, Marketing, Product Management
Roles: Content Marketer, Frontend Developer, Product Manager, Translator, UX Designer
Specialties: Frontend
Tools: Next Intl
Country applicability: Country not specified
Classification basis: Source catalog labels
Instruction SHA-256: e98d4c6d8b43168284e7ebd29686498b97c5ad87216049ced15f630e2c1e9179
Metadata reviewed: 2026-10-27
This metadata supersedes earlier Dave AI catalog attribution. Original instruction and supporting files are preserved.