Upgrade readiness status API

IMPORTANT: This documentation is no longer updated. Refer to Elastic's version policy and the latest documentation.

The underlying Upgrade Assistant concepts are stable, but the APIs for managing Upgrade Assistant are experimental.

Check the status of your cluster.

GET <kibana host>:<port>/api/upgrade_assistant/status?targetVersion=9.0.0

200: Indicates a successful call.
403: Indicates a forbidden request when the upgrade path is not supported (e.g. upgrading more than 1 major or downgrading)

The API returns the following:

{
  "readyForUpgrade": false,
  "details":"The following issues must be resolved before upgrading: 1 Elasticsearch deprecation issue."
}