The marketing site puts locale in the path (/zh/…). Product apps like Research AI switch language in the header and persist to localStorage. SEO still has to ship.

What we added

Classic SEO

• buildPageMetadata() — canonical, OG, Twitter on main routes
• sitemap.xml — home, portfolio, compare, about, legal, featured topics
• robots.txt → sitemap

AEO (AI answer engines)

• public/llms.txt — flows, topic URLs, FAQ, legal links
• JSON-LD graph: Organization, WebSite, SoftwareApplication, FAQPage
• Visible homepage FAQ (en/zh/ko) — same Q&A as schema via lib/seo-faq.ts

Hidden FAQ schema alone is not enough. Crawlers and humans should see the same facts.

What we did not do

Per-locale canonical paths or hreflang — not until routing changes. One URL per page; UI locale is independent.

Checklist mindset

Copied from xingai-dot-app/docs/seo-aeo-checklist.md, adapted for cookie-locale products.

Further reading: ADR-010 in xingai-research-ai/docs/adr/