preference | String | Specifies a preference of which shard to retrieve results from. Available options are `_local`, which tells the operation to retrieve results from a locally allocated shard replica, and a custom string value assigned to a specific shard replica. By default, OpenSearch executes get document operations on random shards.
realtime | Boolean | Specifies whether the operation should run in realtime. If false, the operation waits for the index to refresh to analyze the source to retrieve data, which makes the operation near-realtime. Default is true.
refresh | Boolean | If true, OpenSearch refreshes shards to make the get operation available to search results. Valid options are `true`, `false`, and `wait_for`, which tells OpenSearch to wait for a refresh before executing the operation. Default is `false`.
_source | String | Whether to include the `_source` field in the response body. Default is true.
_source_excludes | String | A comma-separated list of source fields to exclude in the query response.
_source_includes | String | A comma-separated list of source fields to include in the query response.
version | Integer | The version of the document to return, which must match the current version of the document.
version_type | Enum | Retrieves a specifically typed document. Available options are `external` (retrieve the document if the specified version number is greater than the document's current version) and `external_gte` (retrieve the document if the specified version number is greater than or equal to the document's current version). For example, to retrieve version 3 of a document, use `/_doc/1?version=3&version_type=external`.
primary_term | The primary term assigned when the document is indexed.
found | Whether the document exists.
_routing | The shard that the document is routed to. If the document is not routed to a particular shard, this field is omitted.
_source | Contains the document's data if `found` is true. If `_source` is set to false or `stored_fields` is set to true in the URL parameters, this field is omitted.
_fields | Contains the document's data that's stored in the index. Only returned if both `stored_fields` and `found` are true.