Meta

The _meta field is a mapping property that allows you to attach custom metadata to your index mappings. This metadata can be used by your application to store information relevant to your use case, such as versioning, ownership, categorization, or auditing.

Usage

You can define the _meta field when creating a new index or updating an existing index’s mapping, as shown in the following example request:

PUT my-index
{
  "mappings": {
    "_meta": {
      "application": "MyApp",
      "version": "1.2.3",
      "author": "John Doe"
    },
    "properties": {
      "title": {
        "type": "text"
      },
      "description": {
        "type": "text"
      }
    }
  }
}

In this example, three custom metadata fields are added: application, version, and author. These fields can be used by your application to store any relevant information about the index, such as the application it belongs to, the application version, or the author of the index.

You can update the _meta field using the Put Mapping API operation, as shown in the following example request:

PUT my-index/_mapping
{
  "_meta": {
    "application": "MyApp",
    "version": "1.3.0",
    "author": "Jane Smith"
  }
}

Retrieving meta information

You can retrieve the _meta information for an index using the Get Mapping API operation, as shown in the following example request:

GET my-index/_mapping

The response returns the full index mapping, including the _meta field:

{
  "my-index": {
    "mappings": {
      "_meta": {
        "application": "MyApp",
        "version": "1.3.0",
        "author": "Jane Smith"
      },
      "properties": {
        "description": {
          "type": "text"
        },
        "title": {
          "type": "text"
        }
      }
    }
  }
}