# Tracker Trackers maintain the state of a dialogue between the assistant and the user in the form of conversation sessions. To learn more about how to configure the session behaviour, check out the docs on [Session configuration](https://legacy-docs-v1.rasa.com/1.7.1/core/domains/#session-config). ## `class rasa.core.trackers.DialogueStateTracker(sender_id, slots, max_event_history=None, sender_source=None)` Maintains the state of a conversation. The field `max_event_history` will only give you these last events, it can be set in the tracker_store. ### `applied_events()` Returns all actions that should be applied - without reverted events. Return type: `List[Event]` ### `as_dialogue()` Return a `Dialogue` object containing all of the turns. This can be serialized and later used to recover the state of this tracker exactly. Return type: `Dialogue` ### `change_form_to(form_name)` Activate or deactivate a form. Return type: `None` ### `clear_followup_action()` Clears follow up action when it was executed. Return type: `None` ### `copy()` Creates a duplicate of this tracker. Return type: `DialogueStateTracker` ### `current_slot_values()` Return the currently set values of the slots. Return type: `Dict[str, Any]` ### `current_state(event_verbosity=)` Return the current tracker state as an object. Return type: `Dict[str, Any]` ### `events_after_latest_restart()` Return a list of events after the most recent restart. Return type: `List[Event]` ### `export_stories(e2e=False, include_source=False)` Dump the tracker as a story in the Rasa Core story format. Return type: `str` ### `export_stories_to_file(export_path='debug.md')` Dump the tracker as a story to a file. Return type: `None` ### `classmethod from_dict(sender_id, events_as_dict, slots=None, max_event_history=None)` Create a tracker from dump. Return type: `DialogueStateTracker` ### `get_last_event_for(event_type, action_names_to_exclude=None, skip=0)` Gets the last event of a given type which was actually applied. Returns `event` which matched the query or `None` if no event matched. Return type: `Optional[Event]` ### `current_slot_values()` Return the currently set values of the slots. Return type: `Dict[str, Any]` ### `get_slot(key)` Retrieves the value of a slot. Return type: `Optional[Any]` ### `trigger_followup_action(action)` Triggers another action following the execution of the current. Return type: `None`