Tool UI language
The ai-i18n-tools localizes its own user interface — CLI help text, high-traffic log/summary/error messages, and the Translation Dashboard — independently of your project's sourceLocale / targetLocales. No configuration is required: by default the tool follows your OS locale.
Locale resolution
The UI locale is resolved from these sources, highest priority first:
-L/--ui-lang <code>global flag (e.g.-L pt-BR).AI_I18N_LANGenvironment variable (e.g.export AI_I18N_LANG=es).- The
uiLanguageconfig key inai-i18n-tools.config.json(BCP-47 string). - The host OS locale (via
Intl.DateTimeFormat().resolvedOptions().locale).
Matching and fallback
The requested locale is matched against the shipped UI languages exactly or by closest variation (for example pt-PT resolves to pt-BR, and en-US resolves to en-GB); when nothing matches it falls back to the source locale (en-GB). When a UI language is requested explicitly (via the flag, env var, or uiLanguage) but no shipped bundle matches, the CLI prints a one-time warning that the default locale will be used; a locale inferred only from the host OS never warns.
Shipped UI languages
English (UK, source), German, Spanish, French, Hindi, Japanese, Korean, Portuguese (Brazil), Chinese (Simplified), Chinese (Traditional).
Translation Dashboard
The Translation Dashboard reads the resolved locale, layout direction, and translation bundle from GET /api/ui-i18n and applies them on load (it sets <html lang> / dir and localizes static markup via data-i18n* attributes).
Related
AI_I18N_LANG— environment variable overrideuiLanguage— config key override-L/--ui-lang— CLI flag override (highest priority)