These docs are for version 1.x of Rasa Open Source.

# User Guide

- [Installation](https://legacy-docs-v1.rasa.com/1.8.3/user-guide/installation/)
- [Tutorial: Rasa Basics](https://legacy-docs-v1.rasa.com/1.8.3/user-guide/rasa-tutorial/)
- [Tutorial: Building Assistants](https://legacy-docs-v1.rasa.com/1.8.3/user-guide/building-assistants/)
- [Command Line Interface](https://legacy-docs-v1.rasa.com/1.8.3/user-guide/command-line-interface/)
- [Architecture](https://legacy-docs-v1.rasa.com/1.8.3/user-guide/architecture/)
- [Messaging and Voice Channels](https://legacy-docs-v1.rasa.com/1.8.3/user-guide/messaging-and-voice-channels/)
- [Evaluating Models](https://legacy-docs-v1.rasa.com/1.8.3/user-guide/evaluating-models/)
- [Validate Data](https://legacy-docs-v1.rasa.com/1.8.3/user-guide/validate-files/)
- [Configuring the HTTP API](https://legacy-docs-v1.rasa.com/1.8.3/user-guide/configuring-http-api/)
- [Deploying Your Rasa Assistant](https://legacy-docs-v1.rasa.com/1.8.3/user-guide/how-to-deploy/)
- [Cloud Storage](https://legacy-docs-v1.rasa.com/1.8.3/user-guide/cloud-storage/)

# NLU

- [About](https://legacy-docs-v1.rasa.com/1.8.3/nlu/about/)
- [Using NLU Only](https://legacy-docs-v1.rasa.com/1.8.3/nlu/using-nlu-only/)
- [Training Data Format](https://legacy-docs-v1.rasa.com/1.8.3/nlu/training-data-format/)
- [Choosing a Pipeline](https://legacy-docs-v1.rasa.com/1.8.3/nlu/choosing-a-pipeline/)
- [Language Support](https://legacy-docs-v1.rasa.com/1.8.3/nlu/language-support/)
- [Entity Extraction](https://legacy-docs-v1.rasa.com/1.8.3/nlu/entity-extraction/)
- [Components](https://legacy-docs-v1.rasa.com/1.8.3/nlu/components/)

# Core

- [About](https://legacy-docs-v1.rasa.com/1.8.3/core/about/)
- [Stories](https://legacy-docs-v1.rasa.com/1.8.3/core/stories/)
- [Domains](https://legacy-docs-v1.rasa.com/1.8.3/core/domains/)
- [Responses](https://legacy-docs-v1.rasa.com/1.8.3/core/responses/)
- [Actions](https://legacy-docs-v1.rasa.com/1.8.3/core/actions/)
- [Reminders and External Events](https://legacy-docs-v1.rasa.com/1.8.3/core/reminders-and-external-events/)
- [Policies](https://legacy-docs-v1.rasa.com/1.8.3/core/policies/)
- [Slots](https://legacy-docs-v1.rasa.com/1.8.3/core/slots/)
- [Forms](https://legacy-docs-v1.rasa.com/1.8.3/core/forms/)
- [Retrieval Actions](https://legacy-docs-v1.rasa.com/1.8.3/core/retrieval-actions/)
- [Interactive Learning](https://legacy-docs-v1.rasa.com/1.8.3/core/interactive-learning/)
- [Fallback Actions](https://legacy-docs-v1.rasa.com/1.8.3/core/fallback-actions/)
- [Knowledge Base Actions](https://legacy-docs-v1.rasa.com/1.8.3/core/knowledge-bases/)

# Conversation Design

- [Dialogue Elements](https://legacy-docs-v1.rasa.com/1.8.3/dialogue-elements/dialogue-elements/)
- [Small Talk](https://legacy-docs-v1.rasa.com/1.8.3/dialogue-elements/small-talk/)
- [Completing Tasks](https://legacy-docs-v1.rasa.com/1.8.3/dialogue-elements/completing-tasks/)
- [Guiding Users](https://legacy-docs-v1.rasa.com/1.8.3/dialogue-elements/guiding-users/)

# API Reference

- [Action Server](https://legacy-docs-v1.rasa.com/1.8.3/api/action-server/)
- [HTTP API](https://legacy-docs-v1.rasa.com/1.8.3/api/http-api/)
- [Jupyter Notebooks](https://legacy-docs-v1.rasa.com/1.8.3/api/jupyter-notebooks/)
- [Agent](https://legacy-docs-v1.rasa.com/1.8.3/api/agent/)
- [Custom NLU Components](https://legacy-docs-v1.rasa.com/1.8.3/api/custom-nlu-components/)
- [Rasa SDK](https://legacy-docs-v1.rasa.com/1.8.3/api/rasa-sdk/)
- [Events](https://legacy-docs-v1.rasa.com/1.8.3/api/events/)
- [Tracker](https://legacy-docs-v1.rasa.com/1.8.3/api/tracker/#)
- [Tracker Stores](https://legacy-docs-v1.rasa.com/1.8.3/api/tracker-stores/)
- [Event Brokers](https://legacy-docs-v1.rasa.com/1.8.3/api/event-brokers/)
- [Lock Stores](https://legacy-docs-v1.rasa.com/1.8.3/api/lock-stores/)
- [Training Data Importers](https://legacy-docs-v1.rasa.com/1.8.3/api/training-data-importers/)
- [Featurization of Conversations](https://legacy-docs-v1.rasa.com/1.8.3/api/core-featurization/)
- [TensorFlow Configuration](https://legacy-docs-v1.rasa.com/1.8.3/api/tensorflow_usage/)
- [Migration Guide](https://legacy-docs-v1.rasa.com/1.8.3/migration-guide/)
- [Rasa Open Source Change Log](https://legacy-docs-v1.rasa.com/1.8.3/changelog/)

# Migrate from (beta)

- [Dialogflow](https://legacy-docs-v1.rasa.com/1.8.3/migrate-from/google-dialogflow-to-rasa/)
- [Wit.ai](https://legacy-docs-v1.rasa.com/1.8.3/migrate-from/facebook-wit-ai-to-rasa/)
- [LUIS](https://legacy-docs-v1.rasa.com/1.8.3/migrate-from/microsoft-luis-to-rasa/)
- [IBM Watson](https://legacy-docs-v1.rasa.com/1.8.3/migrate-from/ibm-watson-to-rasa/)

# Reference

- [Glossary](https://legacy-docs-v1.rasa.com/1.8.3/glossary/)

# 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/1.8.3/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 - w/o 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](https://legacy-docs-v1.rasa.com/1.8.3/api/tracker/#rasa.core.trackers.DialogueStateTracker)

- **`current_slot_values()`**  
Return the currently set values of the slots.

Return type: `Dict[str, Any]`

- **`current_state(event_verbosity=<EventVerbosity.NONE: 1>)`**  
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.

Returns the dumped tracker as a string.

Return type: `str`

- **`export_stories_to_file(export_path='debug.md')`**  
Dump the tracker as a story to a file.

Return type: `None`

- **`from_dict(sender_id, events_as_dict, slots=None, max_event_history=None)`**  
Create a tracker from dump.

Return type: [DialogueStateTracker](https://legacy-docs-v1.rasa.com/1.8.3/api/tracker/#rasa.core.trackers.DialogueStateTracker)

- **`generate_all_prior_trackers()`**  
Returns a generator of the previous trackers of this tracker.

Return type: `Generator[ DialogueStateTracker, None, None]`

- **`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.

Return type: `Optional[Event]`

- **`get_latest_entity_values(entity_type, entity_role=None, entity_group=None)`**  
Get entity values found for the passed entity type and optional role and group in latest message.

Return type: `Iterator[str]`

- **`get_latest_input_channel()`**  
Get the name of the input_channel of the latest UserUttered event.

Return type: `Optional[str]`

- **`get_slot(key)`**  
Retrieves the value of a slot.

Return type: `Optional[Any]`

- **`idx_after_latest_restart()`**  
Return the idx of the most recent restart in the list of events.

Return type: `int`

- **`init_copy()`**  
Creates a new state tracker with the same initial values.

Return type: [DialogueStateTracker](https://legacy-docs-v1.rasa.com/1.8.3/api/tracker/#rasa.core.trackers.DialogueStateTracker)

- **`is_paused()`**  
State whether the tracker is currently paused.

Return type: `bool`

- **`last_executed_action_has(name, skip=0)`**  
Returns whether last ActionExecuted event had a specific name.

Return type: `bool`

- **`past_states(domain)`**  
Generate the past states of this tracker based on the history.

Return type: `deque`

- **`recreate_from_dialogue(dialogue)`**  
Use a serialized Dialogue to update the trackers state.

Return type: `None`

- **`reject_action(action_name)`**  
Notify active form that it was rejected.

Return type: `None`

- **`replay_events()`**  
Update the tracker based on a list of events.

Return type: `None`

- **`set_form_validation(validate)`**  
Toggle form validation.

Return type: `None`

- **`set_latest_action_name(action_name)`**  
Set latest action name and reset form validation and rejection parameters.

Return type: `None`

- **`travel_back_in_time(target_time)`**  
Creates a new tracker with a state at a specific timestamp.

Return type: [DialogueStateTracker](https://legacy-docs-v1.rasa.com/1.8.3/api/tracker/#rasa.core.trackers.DialogueStateTracker)

- **`trigger_followup_action(action)`**  
Triggers another action following the execution of the current.

Return type: `None`

- **`update(event, domain=None)`**  
Modify the state of the tracker according to an Event.

Return type: `None`
