OptionalcarouselOptionalchainingReels: zero-based chaining position; defaults to 0.
OptionalchainingSeed media id of the chaining session, sent as both starting_clips_media_id
and chaining_seed_media_id; the string "null" when the caller has none
(the short-url comment of the 451 app has no chaining seed).
OptionalchainingReels: opaque chaining-session id.
OptionalclientReels: client position in the viewer; defaults to 0.
OptionalcommentUUID sent as both comment_creation_key and idempotence_token; generated
when absent. Retrying with the same key deduplicates the comment.
OptionalfeedFeed: position of the acted-on item; defaults to 0.
OptionalfullyFeed: media-note ids visible in the composer (chained from a create-note response).
OptionalisContainer media id (<pk>_<authorPk>).
OptionalnumFeed: number of media notes visible in the composer; defaults to 0.
OptionalrankingRanking session id; empty when the surface does not rank (feed).
OptionalrecsFeed recommendation index; defaults to -1.
OptionalreplyComment being replied to; omitted for a top-level comment.
OptionalstoryReels: story ranking token of the reel.
OptionalsurfaceSurface the comment is composed on; defaults to feed. Selects the field
set: the comment has the contextual feed's and the reels viewer's
layouts, so the timeline's like surface ('timeline') cannot be named here.
The comment text.
Carousel child index; a media with no carousel child names
-1.