Localize docs

Leadtype localizes the whole pipeline from one config block: locale-prefixed URLs, a per-locale llms.txt, llms-full.txt, markdown mirror set, search index, sitemap, and robots file, plus an i18n-manifest.json and alternate-locale links. The default locale stays at the docs root; each translation lives under a /{locale} prefix.

1. Enable i18n

export default defineDocsConfig({
  product: { name: "My library", tagline: "..." },
  navigation: ["index"],
  i18n: {
    defaultLocale: "en",
    locales: ["en", "zh", { code: "fr", label: "Français" }],
    // fallback: "default" (the default) serves the default-locale page
    // wherever a translation is missing.
  },
});

2. Author content

Put default-locale pages at the docs root and each translation under a folder named for its locale code:

• The default locale (en here) is the unprefixed content. Put it at the root or under docs/en/ — not both. Mixing the two raises an "Ambiguous i18n default-locale output" error.
• A translation only needs the pages it has translated. With fallback: "default", missing pages (e.g. fr/index.mdx above) resolve to the default-locale page, and the alternate-locale link is marked isFallback: true.

3. Generate per-locale artifacts

One leadtype generate run produces every locale:

npx leadtype generate --src . --out public --base-url https://example.com

public/
├── llms.txt                      # default locale (en)
├── llms-full.txt
└── docs/
    ├── quickstart.md             # en mirrors at the root
    ├── i18n-manifest.json        # locales + per-locale artifact paths
    ├── zh/
    │   ├── llms.txt              # zh index
    │   ├── quickstart.md
    │   └── …
    └── fr/
        └── …

The i18n-manifest.json maps each locale to its generated files, so the runtime can serve the right artifacts per locale.

4. Render locale-prefixed routes

Build one source per locale by passing i18n and the active locale to createDocsSource. The locale selects which pages load (with default-locale fallback); the rest of the wiring is the same docs route you already have, parameterized by locale.

import { createDocsSource } from "leadtype";
import docsConfig from "./docs.config";

export function getSource(locale: string) {
  return createDocsSource({
    contentDir: "./docs",
    nav: docsConfig.navigation,
    baseUrl: "https://example.com",
    i18n: docsConfig.i18n,
    locale,
  });
}

Resolve the active locale from the request path with resolveDocsLocale, and route translated locales under /docs/{locale}/… (the default locale stays at /docs/…). See Use the source primitive for the per-framework route shape.

5. Add alternate-locale links

Emit <link rel="alternate" hreflang> so search engines and agents discover translations. getAlternateLocaleLinks returns one entry per locale that has a matching page:

const alternates = getAlternateLocaleLinks(page, pagesByLocale, docsConfig.i18n);
// → [{ locale: "en", urlPath: "/docs/quickstart", isFallback: false }, … ]

Render each as <link rel="alternate" hreflang={locale} href={urlPath} /> in the page head, next to the canonical and markdown-alternate links from Serve agent responses.

6. Verify

curl https://example.com/llms.txt          # default locale
curl https://example.com/docs/zh/llms.txt  # translated locale
curl https://example.com/docs/zh/quickstart.md
curl https://example.com/docs/i18n-manifest.json

Each locale's llms.txt should link .md URLs under that locale's prefix, and the manifest should list every locale with its artifact paths.