Skip to content
s0vers
Projects

Agent skills for Next.js i18n and SEO

Eight skills that teach coding agents how to do internationalization and SEO properly in Next.js, each with its own evals. They ship inside the i18n starter and install into any project with one command.

Since Sep 2026

Source

npx skills add s0vers/next-app-i18n-starter

Coding agents are confident about Next.js internationalization and SEO, and often out of date. They reach for APIs that were deprecated a release ago, or invent hreflang rules. These skills give an agent the current rules for the job in front of it, and nothing else.

What’s in the set

  • next-intl-i18n covers locale routing, request config, messages, formatting, right-to-left and CJK layout, and localized content, checked against next-intl 4.14 and Next.js 16.3.
  • Seven SEO skills, one per job: technical SEO, international, structured data, commerce, content, measurement, and AI search.

Each skill is a short SKILL.md that sends the agent to playbooks in its own references/ folder, so the agent loads only what the task needs. Every playbook dates its sources and tags each claim as documented, standard, study, practice, or unverified.

Narrow on purpose

The SEO guidance started as one large skill. It was split into seven so an agent working on a sitemap doesn’t also load product-feed and GA4 guidance. Each description also says what the skill is not for, which keeps the wrong one from loading.

Evals, not vibes

Each skill has an evals/evals.json with prompts and pass/fail assertions. The rule for a good assertion: it should fail without the skill. Some prompts come straight from issues people opened on the starter. One asked whether they needed next-sitemap for a multilingual site, and the eval now checks that the agent:

  • recommends the built-in sitemap.ts instead,
  • emits reciprocal language alternates for every locale,
  • never sets lastModified from new Date().

Each skill also has at least eight prompts that should trigger it and eight near misses that shouldn’t, to test its description. bun run skills:check enforces that minimum in CI.

Keeping them current

Platform rules change, so a GitHub Actions workflow runs once a month. It lists playbook sources older than 90 days and any drift between the pinned Next.js and next-intl versions and their latest releases, then opens or updates a single issue to review.

Built with Agent Skills, Markdown, Node.js, GitHub Actions.