# ChapterPagePhoto

A page photo addressed by its media row, never a newly uploaded storageId. A removed row drops the whole slot including its caption on save. Before the chapter-pages migration, legacy read responses retain storage-id photo references from the converter; these cannot be copied into a pages save until migration creates media rows. The same legacy exception applies to authorMediaId and ref mediaId.

Group: Chapters.

## Fields

- `mediaId` (string, required): A spot- or collection-owned media id of this guide. Upload chapter photos with ownerType collection and ownerId collectionId, then reference mediaId. Product and listing owners are refused. No copy is made when reusing a spot photo.
- `caption` (string, optional): Gallery only: optional caption, at most 200 characters. Other page types drop it. Credit belongs to the media row, not this caption.