Set a stack's cover
Pins one of the stack’s own live members as its cover (primary_asset_id). Setting a cover marks the stack as user-owned (origin = user), which freezes it — membership included — against burst re-detection, so neither the chosen cover nor the frame grouping is ever silently reverted by a later detection pass.
primary_asset_id cannot be null: there is no manual clear-cover operation. A pin clears automatically when the pinned frame is removed from the stack or permanently deleted.
Path Parameters
Stack ID (with asset_stack_ prefix) of the stack to pin a cover on.
Body
Asset ID (with asset_ prefix) to pin as the stack's cover. Must be a live, current member of this stack — get member IDs from list_assets with stack_id.
Response
Successful Response
Represents a group of assets displayed as a single tile.
Unique stack identifier with 'asset_stack_' prefix
Number of live assets in this stack. Excludes trashed members, so it can drop below the number of frames originally grouped.
How a stack came to exist.
auto_burst marks a stack the burst detector created from the time +
EXIF-camera signal; user marks a stack a user created or edited (manual
create, set-cover, add/remove, unstack). The distinction is what keeps
re-detection from stomping a user's correction — the detection pass skips
user stacks.
auto_burst, user When this stack was created
When this stack was last updated
ID of the asset the user pinned as the stack's cover, or null if none is pinned. Null for an auto-detected burst unless a user has since pinned a cover — there is no server-selected default, so a client showing a stack with no pinned cover picks its own. A pinned cover that has been trashed keeps its ID here; it is cleared only once the asset is permanently deleted.