Supported Languages

Seelen UI maintains a single, authoritative list of the languages it supports across the app: the Settings language picker, i18n/translations/ locale files, and the slu resource translate command all draw from this same list.

Where it's defined

The list lives in Rust at:

libs/core/src/constants/mod.rs

as the SUPPORTED_LANGUAGES constant, an array of SupportedLanguage { label, en_label, value } entries — label is the language's native name, en_label is its English name, and value is the language code (e.g. es, pt-BR, zh-CN).

libs/core generates TypeScript bindings for the frontend from this same source, exported as SupportedLanguages in:

libs/core/src/constants/mod.ts

Never hand-edit mod.ts — it is generated. To add, remove, or rename a supported language, edit SUPPORTED_LANGUAGES in mod.rs and regenerate bindings with cd libs/core && deno task build:rs.

Why this matters for resources

Anything that consumes "which languages does Seelen UI support" — the Settings language dropdown, and the slu resource translate command described in ResourceText — reads from this list. Adding a language here automatically:

• Makes it selectable in the Settings language picker (once a matching locale file exists under i18n/translations/).
• Makes slu resource translate fill it in for every ResourceText field in a resource, with no changes needed on the resource author's side.

Because both frontend and CLI derive from the same Rust source, the list never drifts between "languages the UI offers" and "languages resources get translated into" — check mod.rs directly for the current, exact list rather than keeping a separate copy of it in documentation.