Stories newest-first by the time of their latest article (last_material_at): stories with a published summary and importance >= 7. Keyset pagination: omit cursor for the newest page, pass next_cursor back for the next (older) one; null means the end. Cursors are opaque; an invalid one is a 400. Archive depth is tiered as on the feeds — paging back past your plan's horizon (Free 30 days, Basic 90, Pro 180) returns 403 archive_horizon.

A story keeps moving up this list while articles keep joining it (last_material_at is the keyset), and its summary is rewritten as materials arrive, so re-reading a story_id later can return a different summary — updated_at says when the facts last changed.

{
  "results": [
    {
      "story_id": "788e477c66f3849b"
    }
  ]
}