Source

File: wp-includes/rest-api/endpoints/class-wp-rest-users-controller.php

public function get_collection_params() {
		$query_params = parent::get_collection_params();

		$query_params['context']['default'] = 'view';

		$query_params['exclude'] = array(
			'description' => __( 'Ensure result set excludes specific IDs.' ),
			'type'        => 'array',
			'items'       => array(
				'type' => 'integer',
			),
			'default'     => array(),
		);

		$query_params['include'] = array(
			'description' => __( 'Limit result set to specific IDs.' ),
			'type'        => 'array',
			'items'       => array(
				'type' => 'integer',
			),
			'default'     => array(),
		);

		$query_params['offset'] = array(
			'description' => __( 'Offset the result set by a specific number of items.' ),
			'type'        => 'integer',
		);

		$query_params['order'] = array(
			'default'     => 'asc',
			'description' => __( 'Order sort attribute ascending or descending.' ),
			'enum'        => array( 'asc', 'desc' ),
			'type'        => 'string',
		);

		$query_params['orderby'] = array(
			'default'     => 'name',
			'description' => __( 'Sort collection by object attribute.' ),
			'enum'        => array(
				'id',
				'include',
				'name',
				'registered_date',
				'slug',
				'include_slugs',
				'email',
				'url',
			),
			'type'        => 'string',
		);

		$query_params['slug'] = array(
			'description' => __( 'Limit result set to users with one or more specific slugs.' ),
			'type'        => 'array',
			'items'       => array(
				'type' => 'string',
			),
		);

		$query_params['roles'] = array(
			'description' => __( 'Limit result set to users matching at least one specific role provided. Accepts csv list or single role.' ),
			'type'        => 'array',
			'items'       => array(
				'type' => 'string',
			),
		);

		$query_params['who'] = array(
			'description' => __( 'Limit result set to users who are considered authors.' ),
			'type'        => 'string',
			'enum'        => array(
				'authors',
			),
		);

		/**
		 * Filter collection parameters for the users controller.
		 *
		 * This filter registers the collection parameter, but does not map the
		 * collection parameter to an internal WP_User_Query parameter.  Use the
		 * `rest_user_query` filter to set WP_User_Query arguments.
		 *
		 * @since 4.7.0
		 *
		 * @param array $query_params JSON Schema-formatted collection parameters.
		 */
		return apply_filters( 'rest_user_collection_params', $query_params );
	}