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

# Type Alias: PropConstantKeys

> **PropConstantKeys** = `"contentmodel"` | `"pagelanguage"` | `"pagelanguagehtmlcode"` | `"pagelanguagedir"` | `"touched"` | `"lastrevid"` | `"length"` | `"revisions"`

Defined in: [core/query/index.ts:452](https://github.com/BearBin1215/types-mediawiki-response/blob/d354a9c689faf74c19e13b617a83dcdb7a83726f/src/core/query/index.ts#L452)

`prop=` fields their module writes unconditionally on an existing page. On
[QueryPageExisting](https://types-mediawiki-response.pages.dev/api/core/QueryPageExisting.md) these are required when picked; on the all-state
[QueryPage](https://types-mediawiki-response.pages.dev/api/core/QueryPage.md) they stay optional, because invalid/special entries never
carry prop fields. Every other `prop=` key is omitted when its data is
absent (empty lists, non-file pages, non-category pages), so it stays
optional even on [QueryPageExisting](https://types-mediawiki-response.pages.dev/api/core/QueryPageExisting.md).