Title: rest_query_var-{$key}
Published: December 6, 2016
Last modified: May 20, 2026

---

# apply_filters( “rest_query_var-{$key}”, string $value )

## In this article

 * [Description](https://developer.wordpress.org/reference/hooks/rest_query_var-key/?output_format=md#description)
 * [Parameters](https://developer.wordpress.org/reference/hooks/rest_query_var-key/?output_format=md#parameters)
 * [Source](https://developer.wordpress.org/reference/hooks/rest_query_var-key/?output_format=md#source)
 * [Related](https://developer.wordpress.org/reference/hooks/rest_query_var-key/?output_format=md#related)
 * [Changelog](https://developer.wordpress.org/reference/hooks/rest_query_var-key/?output_format=md#changelog)

[ Back to top](https://developer.wordpress.org/reference/hooks/rest_query_var-key/?output_format=md#wp--skip-link--target)

Filters the query_vars used in get_items() for the constructed query.

## 󠀁[Description](https://developer.wordpress.org/reference/hooks/rest_query_var-key/?output_format=md#description)󠁿

The dynamic portion of the hook name, `$key`, refers to the query_var key.

## 󠀁[Parameters](https://developer.wordpress.org/reference/hooks/rest_query_var-key/?output_format=md#parameters)󠁿

 `$value`string

The query_var value.

## 󠀁[Source](https://developer.wordpress.org/reference/hooks/rest_query_var-key/?output_format=md#source)󠁿

    ```php
    $query_args[ $key ] = apply_filters( "rest_query_var-{$key}", $value ); // phpcs:ignore WordPress.NamingConventions.ValidHookName.UseUnderscores
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/7.0/src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php#L1231)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/7.0/src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php#L1231-L1231)

## 󠀁[Related](https://developer.wordpress.org/reference/hooks/rest_query_var-key/?output_format=md#related)󠁿

| Used by | Description | 
| [WP_REST_Revisions_Controller::prepare_items_query()](https://developer.wordpress.org/reference/classes/wp_rest_revisions_controller/prepare_items_query/)`wp-includes/rest-api/endpoints/class-wp-rest-revisions-controller.php` |

Determines the allowed query_vars for a get_items() response and prepares them for [WP_Query](https://developer.wordpress.org/reference/classes/wp_query/).

  | 
| [WP_REST_Posts_Controller::prepare_items_query()](https://developer.wordpress.org/reference/classes/wp_rest_posts_controller/prepare_items_query/)`wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php` |

Determines the allowed query_vars for a get_items() response and prepares them for [WP_Query](https://developer.wordpress.org/reference/classes/wp_query/).

  |

## 󠀁[Changelog](https://developer.wordpress.org/reference/hooks/rest_query_var-key/?output_format=md#changelog)󠁿

| Version | Description | 
| [4.7.0](https://developer.wordpress.org/reference/since/4.7.0/) | Introduced. |

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