[role="xpack"]
[[ilm-put-lifecycle]]
=== Create or update lifecycle policy API
++++
<titleabbrev>Create or update lifecycle policy</titleabbrev>
++++

.New API reference
[sidebar]
--
For the most up-to-date API details, refer to {api-es}/group/endpoint-ilm[{ilm-cap} APIs].
--

Creates or updates <<index-lifecycle-management,lifecycle>> policy. See <<ilm-index-lifecycle>> for
definitions of policy components.

[[ilm-put-lifecycle-request]]
==== {api-request-title}

`PUT _ilm/policy/<policy_id>`

[[ilm-put-lifecycle-prereqs]]
==== {api-prereq-title}

* If the {es} {security-features} are enabled, you must have the `manage_ilm`
cluster privilege to use this API. You must also have the `manage` index
privilege on all indices being managed by `policy`. {ilm-init} performs
operations as the user who last updated the policy. {ilm-init} only has the
<<defining-roles,roles>> assigned to the user at the time of the last policy
update.

[[ilm-put-lifecycle-desc]]
==== {api-description-title}

Creates a lifecycle policy. If the specified policy exists, the policy is
replaced and the policy version is incremented.

NOTE: Only the latest version of the policy is stored, you cannot revert to
previous versions.

[[ilm-put-lifecycle-path-params]]
==== {api-path-parms-title}

`<policy_id>`::
  (Required, string) Identifier for the policy.
+
[IMPORTANT]
====
To avoid naming collisions with built-in and Fleet-managed ILM policies, avoid using `@` as part of the id of your own ILM policies.
====

[[ilm-put-lifecycle-query-params]]
==== {api-query-parms-title}

include::{es-ref-dir}/rest-api/common-parms.asciidoc[tag=timeoutparms]

[[ilm-put-lifecycle-example]]
==== {api-examples-title}

The following example creates a new policy named `my_policy`. In addition, you can use the
`_meta` parameter to add arbitrary metadata to the policy, the `_meta` parameter is optional
and not automatically generated or used by Elasticsearch. To unset `_meta`, replace the policy
without specifying one. To check the `_meta`, you can use the <<ilm-get-lifecycle,Get lifecycle policy>> API.

[source,console]
--------------------------------------------------
PUT _ilm/policy/my_policy
{
  "policy": {
    "_meta": {
      "description": "used for nginx log",
      "project": {
        "name": "myProject",
        "department": "myDepartment"
      }
    },
    "phases": {
      "warm": {
        "min_age": "10d",
        "actions": {
          "forcemerge": {
            "max_num_segments": 1
          }
        }
      },
      "delete": {
        "min_age": "30d",
        "actions": {
          "delete": {}
        }
      }
    }
  }
}
--------------------------------------------------

If the request succeeds, you receive the following result:

[source,console-result]
----
{
  "acknowledged": true
}
----
