gitlab-ce/app/assets/javascripts/monitoring/queries/getAnnotations.query.graphql

query getAnnotations($projectPath: ID!) {
  environment(name: $environmentName) {
    metricDashboard(id: $dashboardId) {
      annotations: nodes {
        id
        description
        starting_at
        ending_at
        panelId
      }
    }
  }
}