OpenSearch/rest-api-spec/api/cluster.put_settings.json

{
  "cluster.put_settings": {
    "documentation": "http://www.elasticsearch.org/guide/en/elasticsearch/reference/master/cluster-update-settings.html",
    "methods": ["PUT"],
    "url": {
      "path": "/_cluster/settings",
      "paths": ["/_cluster/settings"],
      "parts": {},
      "params": {
        "flat_settings": {
          "type": "boolean",
          "description": "Return settings in flat format (default: false)"
        }
      }
    },
    "body": {
      "description": "The settings to be updated. Can be either `transient` or `persistent` (survives cluster restart)."
    }
  }
}