Source

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

protected function prepare_links( $item ) {
		return array(
			'self' => array(
				'href' => rest_url( sprintf( '%s/%s/%s', $this->namespace, $this->rest_base, substr( $item['_file'], 0, - 4 ) ) ),
			),
		);
	}