A cursor for use in pagination. before is an object ID that defines your place in the list. For instance, if you make a list request and receive 100 objects, ending with obj_foo, your subsequent call can include before=obj_foo in order to fetch the previous page of the list.

Sort order by the created_at timestamp of the objects. asc for ascending order and desc for descending order.

Filter messages by the run ID that generated them.