Instructions

When to Use

• Use for locales, routing, message files, RTL notes.
• Prefer seo-expert for hreflang and locale metadata depth.
• Prefer next-server-patterns for locale-aware RSC.

Plan i18n for Next.js App Router without locking to one vendor library unless the repo already uses it.

1. Routing: [locale] segment vs subdomain - pros for SEO and DX; pick one.
2. Message catalogs: namespace per feature; avoid mega JSON files.
3. SEO: hreflang pairs, canonical per locale, localized titles in metadata.
4. RTL: dir on html or layout wrapper; mirror spacing where needed.
5. Dates and numbers: Intl or established lib - match stack.

Outcomes

• Locale routing sketch + message file tree + SEO checklist.