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 a response to the domain file that starts with utter_:

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

If you use an external NLG service, you don’t need to specify the responses in the domain, but you still need to add the utterance names to the actions list of the domain.

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 Rasa SDK which starts this action server for you.

Execute Actions in Other Code

Rasa will send an HTTP POST request to your server containing information on which action to run. Furthermore, this request will contain all information about the conversation.

Default Actions

The available default actions are:

Action Name	Description
`action_listen`	Stop predicting more actions and wait for user input.
`action_restart`	Reset the whole conversation.
`action_session_start`	Start a new conversation session.
`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 overridden. To do so, add the action name to the list of actions in your domain:

actions:
- action_default_ask_affirmation

Rasa will then call your action endpoint and treat it as every other custom action.