# Simple responses

![Example of a simple response on a mobile device](https://developers.google.com/static/assistant/conversational/images/simple-response.png)

Simple responses take the form of a chat bubble visually and use text-to-speech
(TTS) or Speech Synthesis Markup Language (SSML) for sound. By using short
simple responses in conversation, you can keep users engaged with a clear visual
and audio interface that can be paired with other conversational elements.

Chat bubble content in a simple response must be a phonetic subset or a complete
transcript of the TTS/SSML output. This helps users map out what your Action
says and increases comprehension in various conditions.

In a prompt, text you provide in the `first_simple` and `last_simple` objects
use the properties of a simple response. Google Assistant sends all simple
responses in a prompt, then sends the final rich response in the prompt queue.

> [!NOTE]
> **Note:** Some surfaces (like smart displays) only display one piece of content at a time instead of using the chat bubble format. As a result, only the rich response appears when you provide both a simple and a rich response.

## Properties

The simple response type has the following properties:

| Property | Type | Requirement | Description |
|---|---|---|---|
| `speech` | string | Optional | Represents the words to be spoken to the user in SSML or text-to-speech. If the `override` field in the containing prompt is "true", then speech defined in this field replaces the previous simple prompt's speech. |
| `text` | string | Optional | Text to display in the chat bubble. Strings longer than 640 characters are truncated at the first word break (or whitespace) before 640 characters. We recommend using less than 300 characters to prevent content from extending past the screen, especially when paired with a card or other visual element. If not provided, Assistant renders a display version of the `speech` field instead. If the `override` field in the containing prompt is "false", then text defined in this field is appended to the previous simple prompt's text. |

![Example of a simple response on smart display](https://developers.google.com/static/assistant/conversational/images/smart-display/simple-response.png)

## Sample code

### YAML

```yaml
candidates:
  - first_simple:
      variants:
        - speech: This is the first simple response.
          text: This is the 1st simple response.
    last_simple:
      variants:
        - speech: This is the last simple response.
          text: This is the last simple response.
```

### JSON

```
{
  "candidates": [
    {
      "first_simple": {
        "variants": [
          {
            "speech": "This is the first simple response.",
            "text": "This is the 1st simple response."
          }
        ]
      },
      "last_simple": {
        "variants": [
          {
            "speech": "This is the last simple response.",
            "text": "This is the last simple response."
          }
        ]
      }
    }
  ]
}
```

### Node.js

```javascript
app.handle('Simple', conv => {
  conv.add(new Simple({
    speech: 'This is the first simple response.',
    text: 'This is the 1st simple response.'
  }));
  conv.add(new Simple({
    speech: 'This is the last simple response.',
    text: 'This is the last simple response.'
  }));
});
```

### JSON

```
{
  "responseJson": {
    "session": {
      "id": "session_id",
      "params": {}
    },
    "prompt": {
      "override": false,
      "firstSimple": {
        "speech": "This is the first simple response.",
        "text": "This is the 1st simple response."
      },
      "lastSimple": {
        "speech": "This is the last simple response.",
        "text": "This is the last simple response."
      }
    }
  }
}
```

## SSML and sounds

Use SSML and sounds in your responses to give them more polish and enhance the
user experience. See the [SSML documentation](https://developers.google.com/assistant/conversational/ssml) for more information.

## Sound library

We provide a variety of free, short sounds in our [sound library](https://developers.google.com/assistant/tools/sound-library). These
sounds are hosted for you, so all you need to do is include them in your SSML.