Public API

The Public API is the small, stable surface your application calls at runtime (or at build time) to fetch translations. It's authenticated with API keys, never with user-session tokens, and lives at a separate base path from the full LangSync API.

Where to find it

Endpoints live under the LangSync service host – the same host as the main API, under the /api/v1/... prefix. See the Swagger UI on your LangSync service for exact paths.

Authentication

Authorization: Apikey <your-api-key>

Bearer is also accepted with the same key value, for clients that hard-code the scheme. Anything else returns 401 Unauthorized.

What's exposed

• List languages for a namespace. Get the languages attached to a namespace, with their IDs, BCP 47 codes, and display names.

• Fetch translations for one language. Returns a flat map from term mark to translated value:

  {
    "translations": {
      "welcome.title": "Willkommen",
      "welcome.subtitle": "Schön, dass Sie hier sind",
      "button.submit": "Absenden"
    }
  }

  Empty translations are returned as empty strings – your i18n library should treat them as missing and fall back to the default language.

What's not exposed

The Public API is intentionally minimal. It does not include:

• Mutating endpoints – use the main API with a session JWT for writes.
• AI translation calls – those run from the dashboard, the CLI, or a sync job.

Caching

Translations change infrequently. Cache aggressively in your CDN or in-process. The endpoint sets Last-Modified so conditional requests with If-Modified-Since return 304 Not Modified when nothing has changed. See Fetch translations for usage patterns.

Limits and errors

Rate-limited like every other LangSync endpoint – see Limits and errors.