> For AI agents: the complete documentation index is available at https://types-mediawiki-response.pages.dev/zh/llms.txt, the full documentation bundle is available at https://types-mediawiki-response.pages.dev/zh/llms-full.txt.

# Universal Language Selector

## Interfaces

| Interface                                                                                                                    | Description                                                                                                                                                                                                                                                                                                                                                                                   |
| ---------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [ApiUlsLocalizationMetadata](https://types-mediawiki-response.pages.dev/zh/api/extensions/uls/ApiUlsLocalizationMetadata.md) | Metadata block of a ULS localization bundle, carried over from the source i18n files. Only the keys the wiki's ULS files actually use appear.                                                                                                                                                                                                                                                 |
| [ApiUlsLocalizationResponse](https://types-mediawiki-response.pages.dev/zh/api/extensions/uls/ApiUlsLocalizationResponse.md) | Response of `action=ulslocalization`: the ULS message bundle for one language (its fallback chain merged in), returned raw as JSON — there is no envelope and no `ulslocalization` wrapper. Keys are ULS message ids (e.g. `uls-region-WW`) mapped to their translation; `@metadata` holds the source file credits. The module is internal to ULS; responses are cached publicly for 28 days. |
| [ApiUlsSetLanguageResponse](https://types-mediawiki-response.pages.dev/zh/api/extensions/uls/ApiUlsSetLanguageResponse.md)   | Response of `action=ulssetlang` (CSRF-token POST): stores the interface language in the named user's preferences. A success response carries no payload keys. Anonymous callers only succeed when `$wgULSAnonCanChangeLanguage` is enabled (then only a cookie is set, likewise with no payload).                                                                                             |