curl --request GET \
  --url https://api.mixpeek.com/v1/clusters/{cluster_id}/groups \
  --header 'Authorization: Bearer <token>'

{
  "cluster_id": "<string>",
  "total_groups": 123,
  "total_documents": 123,
  "groups": [
    {
      "cluster_id": "<string>",
      "member_count": 123,
      "label": "<string>",
      "summary": "<string>",
      "keywords": [
        "<string>"
      ]
    }
  ],
  "run_id": "<string>"
}