## Websocket Channel
The SocketIO channel uses websockets and is real-time. You need to supply a `credentials.yml` with the following content:

```
socketio:
  user_message_evt: user_uttered
  bot_message_evt: bot_uttered
  session_persistence: true/false
```

The first two configuration values define the event names used by Rasa Core when sending or receiving messages over socket.io.

By default, the socketio channel uses the socket id as `sender_id`, which causes the session to restart at every page reload. `session_persistence` can be set to `true` to avoid that. In that case, the frontend is responsible for generating a session id and sending it to the Rasa Core server by emitting the event `session_request` with `{session_id: [session_id]}` immediately after the `connect` event.

The example [Webchat](https://github.com/mrbot-ai/rasa-webchat) implements this session creation mechanism (version >= 0.5.0).

## REST Channels
The `RestInput` and `CallbackInput` channels can be used for custom integrations. They provide a URL where you can post messages and either receive response messages directly, or asynchronously via a webhook.

### RestInput
The `rest` channel will provide you with a REST endpoint to post messages to and in response to that request will send back the bots messages. Here is an example on how to connect the `rest` input channel using the run script:

```
rasa run
```

you need to ensure your `credentials.yml` has the following content:

```
rest:
  # you don't need to provide anything here - this channel doesn't
  # require any credentials
```

After connecting the `rest` input channel, you can post messages to `POST /webhooks/rest/webhook` with the following format:

```
{
  "sender": "Rasa",
  "message": "Hi there!"
}
```

The response to this request will include the bot responses, e.g.

```
[
  {"text": "Hey Rasa!"}, {"image": "http://example.com/image.jpg"}
]
```

### CallbackInput
The `callback` channel behaves very much like the `rest` input, but instead of directly returning the bot messages to the HTTP request that sends the message, it will call a URL you can specify to send bot messages.

Here is an example on how to connect the `callback` input channel using the run script:

```
rasa run
```

you need to supply a `credentials.yml` with the following content:

```
callback:
  # URL to which Core will send the bot responses
  url: "http://localhost:5034/bot"
```

After connecting the `callback` input channel, you can post messages to `POST /webhooks/callback/webhook` with the following format:

```
{
  "sender": "Rasa",
  "message": "Hi there!"
}
```

The response will simply be `success`. Once Core wants to send a message to the user, it will call the URL you specified with a `POST` and the following `JSON` body:

```
[
  {"text": "Hey Rasa!"}, {"image": "http://example.com/image.jpg"}
]
```