public function CHECK_IN_args() {
		return array(
			// QR fields
			'api_key'       => array(
				'required'          => true,
				'validate_callback' => array( $this->validator, 'is_string' ),
				'type'              => 'string',
				'description'       => __( 'The API key to authorize check in.', 'event-tickets-plus' ),
			),
			'ticket_id'     => array(
				'required'          => true,
				'validate_callback' => array( $this->validator, 'is_numeric' ),
				'type'              => 'string',
				'description'       => __( 'The ID of the ticket to check in.', 'event-tickets-plus' ),
			),
			'security_code'     => array(
				'required'          => true,
				'validate_callback' => array( $this->validator, 'is_string' ),
				'type'              => 'string',
				'description'       => __( 'The security code of the ticket to verify for check in.', 'event-tickets-plus' ),
			),
		);
	}