Actions

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

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Glossary

Actions

Actions are the things your bot runs in response to user input. There are four kinds of actions in Rasa:

Utterance actions: start with utter_ and send a specific message to the user.
Retrieval actions: start with respond_ and send a message selected by a retrieval model.
Custom actions: run arbitrary code and send any number of messages (or none).
Default actions: e.g. action_listen, action_restart, action_default_fallback.

Utterance Actions

To define an utterance action (ActionUtterTemplate), add an utterance template to the domain file that starts with utter_:

templates:
  utter_my_message:
    - "this is what I want my action to say!"

It is conventional to start the name of an utterance action with utter_. If this prefix is missing, you can still use the template in your custom actions, but the template cannot be directly predicted as its own action. See Responses for more details.

Retrieval Actions

Retrieval actions make it easier to work with a large number of similar intents like chitchat and FAQs.

Custom Actions

An action can run any code you want. Custom actions can turn on the lights, add an event to a calendar, check a user’s bank balance, or anything else you can imagine.

Rasa will call an endpoint you can specify when a custom action is predicted. This endpoint should be a webserver that reacts to this call, runs the code, and optionally returns information to modify the dialogue state.

To specify your action server use the endpoints.yml:

action_endpoint:
  url: "http://localhost:5055/webhook"

Custom Actions Written in Python

For actions written in Python, we have a convenient SDK which starts this action server for you.

The only thing your action server needs to install is rasa-sdk:

pip install rasa-sdk

The file that contains your custom actions should be called actions.py. Alternatively, you can use a package directory called actions or manually specify an actions module or package with the --actions flag.

If you have rasa installed, run this command to start your action server:

rasa run actions

In a restaurant bot, if the user says “show me a Mexican restaurant”, your bot could execute the action ActionCheckRestaurants, which might look like this:

from rasa_sdk import Action
from rasa_sdk.events import SlotSet

class ActionCheckRestaurants(Action):
   def name(self) -> Text:
      return "action_check_restaurants"

def run(self, dispatcher: CollectingDispatcher, tracker: Tracker, domain: Dict[Text, Any]) -> List[Dict[Text, Any]]:
      cuisine = tracker.get_slot('cuisine')
      q = "select * from restaurants where cuisine='{0}' limit 1".format(cuisine)
      result = db.query(q)
      return [SlotSet("matches", result if result is not None else [])]

Execute Actions in Other Code

Rasa will send an HTTP POST request to your server containing information on which action to run. All modifications are done using events.

Proactively Reaching Out to the User Using Actions

You may want to proactively reach out to the user, for example, to display the output of a long-running background operation or notify the user of an external event.

Default Actions

There are eight default actions:


`action_listen`	Stop predicting more actions and wait for user input.
`action_restart`	Reset the whole conversation. Can be triggered during a conversation by entering `/restart`.
`action_default_fallback`	Undo the last user message and utter a message that the bot did not understand.
`action_deactivate_form`	Deactivate the active form and reset the requested slot.
`action_revert_fallback_events`	Revert events that occurred during the TwoStageFallbackPolicy.
`action_default_ask_affirmation`	Ask the user to affirm their intent.
`action_default_ask_rephrase`	Ask the user to rephrase their intent.
`action_back`	Undo the last user message.

All the default actions can be overwritten by adding the action name to the list of actions in your domain:

actions:
- action_default_ask_affirmation