[role="xpack"]
[testenv="platinum"]
[[ml-get-category]]
=== Get categories API
++++
<titleabbrev>Get categories</titleabbrev>
++++

Retrieves job results for one or more categories.


==== Request

`GET _ml/anomaly_detectors/<job_id>/results/categories` +

`GET _ml/anomaly_detectors/<job_id>/results/categories/<category_id>`

==== Description

For more information about categories, see
{xpack-ref}/ml-configuring-categories.html[Categorizing Log Messages].

==== Path Parameters

`job_id`::
  (string) Identifier for the job.

`category_id`::
  (long) Identifier for the category. If you do not specify this optional parameter,
  the API returns information about all categories in the job.


==== Request Body

`page`::
`from`:::
  (integer) Skips the specified number of categories.
`size`:::
  (integer) Specifies the maximum number of categories to obtain.


==== Results

The API returns the following information:

`categories`::
  (array) An array of category objects. For more information, see
  <<ml-results-categories,Categories>>.


==== Authorization

You must have `monitor_ml`, `monitor`, `manage_ml`, or `manage` cluster
privileges to use this API. You also need `read` index privilege on the index
that stores the results. The `machine_learning_admin` and `machine_learning_user`
roles provide these privileges. For more information, see
{xpack-ref}/security-privileges.html[Security Privileges] and
{xpack-ref}/built-in-roles.html[Built-in Roles].


==== Examples

The following example gets information about one category for the
`esxi_log` job:

[source,js]
--------------------------------------------------
GET _ml/anomaly_detectors/esxi_log/results/categories
{
  "page":{
    "size": 1
  }
}
--------------------------------------------------
// CONSOLE
// TEST[skip:todo]

In this example, the API returns the following information:
[source,js]
----
{
  "count": 11,
  "categories": [
    {
      "job_id" : "esxi_log",
      "category_id" : 1,
      "terms" : "Vpxa verbose vpxavpxaInvtVm opID VpxaInvtVmChangeListener Guest DiskInfo Changed",
      "regex" : ".*?Vpxa.+?verbose.+?vpxavpxaInvtVm.+?opID.+?VpxaInvtVmChangeListener.+?Guest.+?DiskInfo.+?Changed.*",
      "max_matching_length": 154,
      "examples" : [
        "Oct 19 17:04:44 esxi1.acme.com Vpxa: [3CB3FB90 verbose 'vpxavpxaInvtVm' opID=WFU-33d82c31] [VpxaInvtVmChangeListener] Guest DiskInfo Changed",
        "Oct 19 17:04:45 esxi2.acme.com Vpxa: [3CA66B90 verbose 'vpxavpxaInvtVm' opID=WFU-33927856] [VpxaInvtVmChangeListener] Guest DiskInfo Changed",
        "Oct 19 17:04:51 esxi1.acme.com Vpxa: [FFDBAB90 verbose 'vpxavpxaInvtVm' opID=WFU-25e0d447] [VpxaInvtVmChangeListener] Guest DiskInfo Changed",
        "Oct 19 17:04:58 esxi2.acme.com Vpxa: [FFDDBB90 verbose 'vpxavpxaInvtVm' opID=WFU-bbff0134] [VpxaInvtVmChangeListener] Guest DiskInfo Changed"
      ],
      "grok_pattern" : ".*?%{SYSLOGTIMESTAMP:timestamp}.+?Vpxa.+?%{BASE16NUM:field}.+?verbose.+?vpxavpxaInvtVm.+?opID.+?VpxaInvtVmChangeListener.+?Guest.+?DiskInfo.+?Changed.*"
    }
  ]
}
----