# Rasa SDK

Rasa SDK provides the tools you need to write custom actions in python.

## [Installation](https://legacy-docs-v1.rasa.com/1.10.24/api/rasa-sdk/#installation)
Use `pip` to install `rasa-sdk` on your action server.

```
pip install rasa-sdk
```

Note

You do not need to install `rasa` for your action server.
E.g. if you are running Rasa in a docker container, it is recommended to
create a separate container for your action server. In this
separate container, you only need to install `rasa-sdk`.

## [Running the Action Server](https://legacy-docs-v1.rasa.com/1.10.24/api/rasa-sdk/#running-the-action-server)
If you have `rasa` installed, run this command to start your action server:

```
rasa run actions
```

Otherwise, if you do not have `rasa` installed, run this command:

```
python -m rasa_sdk --actions actions
```

You can verify that the action server is up and running with the command:

```
curl http://localhost:5055/health
```

You can get the list of registered custom actions with the command:

```
curl http://localhost:5055/actions
```

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

The full list of options for running the action server with either command is:

```
usage: rasa run actions [-h] [-v] [-vv] [--quiet] [-p PORT]
                        [--cors [CORS [CORS ...]]] [--actions ACTIONS]
                        [--ssl-keyfile SSL_KEYFILE]
                        [--ssl-certificate SSL_CERTIFICATE]
                        [--ssl-password SSL_PASSWORD] [--auto-reload]

optional arguments:
  -h, --help            show this help message and exit
  -p PORT, --port PORT  port to run the server at (default: 5055)
  --cors [CORS [CORS ...]]
                        enable CORS for the passed origin. Use * to whitelist
                        all origins (default: None)
  --actions ACTIONS     name of action package to be loaded (default: None)
  --ssl-keyfile SSL_KEYFILE
                        Set the SSL certificate to create a TLS secured
                        server. (default: None)
  --ssl-certificate SSL_CERTIFICATE
                        Set the SSL certificate to create a TLS secured
                        server. (default: None)
  --ssl-password SSL_PASSWORD
                        If your ssl-keyfile is protected by a password, you
                        can specify it using this paramer. (default: None)
  --auto-reload         Enable auto-reloading of modules containing Action
                        subclasses. (default: False)

Python Logging Options:
  -v, --verbose         Be verbose. Sets logging level to INFO. (default:
                        None)
  -vv, --debug          Print lots of debugging statements. Sets logging level
                        to DEBUG. (default: None)
  --quiet               Be quiet! Sets logging level to WARNING. (default:
                        None)
```

## [Actions](https://legacy-docs-v1.rasa.com/1.10.24/api/rasa-sdk/#actions)
The `Action` class is the base class for any custom action. It has two methods
that both need to be overwritten, `name()` and `run()`.

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 [])]
```

You should add the action name `action_check_restaurants` to
the actions in your domain file. The action’s `run()` method receives
three arguments. You can access the values of slots and the latest message
sent by the user using the `tracker` object, and you can send messages
back to the user with the `dispatcher` object, by calling
`dispatcher.utter_message`.

### Details of the `run()` method:

`async` Action.`run`( _dispatcher_, _tracker_, _domain_) 
Execute the side effects of this action.

Parameters

- **dispatcher** – the dispatcher which is used to
send messages back to the user.
- **tracker** – the state tracker for the current
user.
- **domain** – the bot’s domain

Returns

A dictionary of `rasa_sdk.events.Event` instances that is
returned through the endpoint.

Return type
`List`[`Dict`[`str`, `Any`]]

### Details of the `dispatcher.utter_message()` method:
`CollectingDispatcher.`utter_message`( _text=None_, _image=None_, _json_message=None_, _template=None_, _attachment=None_, _buttons=None_, _elements=None_, _**kwargs_)  
“Send a text to the output channel.

Return type
`None`

### [Customizing the session start action](https://legacy-docs-v1.rasa.com/1.10.24/api/rasa-sdk/#customizing-the-session-start-action)
The default behavior of the session start action is to take all existing slots and to
carry them over into the next session. Let’s say you do not want to carry over all
slots, but only a user’s name and their phone number. To do that, you’d override the
`action_session_start` with a custom action that might look like this:

```
from typing import Text, List, Dict, Any

from rasa_sdk import Action, Tracker
from rasa_sdk.events import SlotSet, SessionStarted, ActionExecuted, EventType
from rasa_sdk.executor import CollectingDispatcher

class ActionSessionStart(Action):
    def name(self) -> Text:
        return "action_session_start"

@staticmethod
    def fetch_slots(tracker: Tracker) -> List[EventType]:
        slots = []
        for key in ("name", "phone_number"):
            value = tracker.get_slot(key)
            if value is not None:
                slots.append(SlotSet(key=key, value=value))
        return slots

async def run(
        self,
        dispatcher: CollectingDispatcher,
        tracker: Tracker,
        domain: Dict[Text, Any],
    ) -> List[EventType]:
        events = [SessionStarted()]
        events.extend(self.fetch_slots(tracker))
        events.append(ActionExecuted("action_listen"))
        return events
```

Note

You need to explicitly add `action_session_start` to your domain to override this
custom action.

## [Events](https://legacy-docs-v1.rasa.com/1.10.24/api/rasa-sdk/#events)
An action’s `run()` method returns a list of events. For more information on
the different types of events, see [Events](https://legacy-docs-v1.rasa.com/1.10.24/api/events/#events). The action itself will automatically be added to the
tracker as an `ActionExecuted` event. If the action should not trigger any
other events, it should return an empty list.

## [Tracker](https://legacy-docs-v1.rasa.com/1.10.24/api/rasa-sdk/#tracker)
The `rasa_sdk.Tracker` lets you access the bot’s memory in your custom
actions. You can get information about past events and the current state of the
conversation through `Tracker` attributes and methods.

The following are available as attributes of a `Tracker` object:

- `sender_id` 
- `slots` 
- `latest_message` 
- `events` 
- `active_form` 
- `latest_action_name`

The available methods from the `Tracker` are:
`Tracker.`current_state`()

Return type
`Dict`[`str`, `Any`]
`Tracker.`is_paused`()

Return type
`bool`

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