> ## Documentation Index
> Fetch the complete documentation index at: https://polyai-mintlify-7055a538.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# SMS Agent Configuration

> Configure your SMS agent's behavior, style, and responses.

Configure SMS alongside your other messaging channels from the **Messaging** page in Agent Studio, under **Channels > Messaging**. The page has three tabs: **General**, **Web chat** and **SMS**.

<Info>
  Settings on the **General** tab apply across all messaging channels unless overridden in a channel's configuration. Anything you set on the **SMS** tab overrides the matching General setting for SMS only.
</Info>

## Activate and Deactivate SMS

SMS is switched on and off from the **Channels** card on the **General** tab, where each messaging channel has its own toggle and status tag.

Turn the SMS toggle on to activate the channel. The status tag changes to **Active**, the SMS tab's settings unlock with defaults pre-filled, and the SMS tab confirms the channel is active and ready to handle SMS conversations. Publish your changes to go live.

Turning the toggle off deactivates the channel. You are asked to confirm first: SMS stops sending and receiving messages, but your configuration is kept and can be reactivated at any time. While SMS is deactivated, the SMS tab shows "SMS is currently disabled" with a link back to the General tab, and its settings are locked.

## SMS Behaviour

SMS is a different medium from web chat: shorter, plainer and billed per message segment. The **SMS behaviour** card on the SMS tab controls how your agent writes on SMS, without touching its underlying knowledge or logic.

Select from the style options to generate an SMS prompt, or write your own:

| Option                 | Choices                                                      |
| ---------------------- | ------------------------------------------------------------ |
| Tone (select multiple) | Neutral, Friendly, Professional, Concise, Empathetic, Casual |
| Emoji use              | No emojis, Enabled                                           |
| Sign-off               | No sign-off, Agent name, Custom                              |
| Opener                 | No opener, Custom                                            |
| Date format            | For example "Fri 16 May", "16 May 2026", "May 16, 2026"      |
| Time format            | For example "3pm", "3:00pm", "15:00"                         |

Your selections generate the **SMS style prompt** automatically, and adjust it as you change options. You can edit the generated prompt directly. For example, a friendly, concise tone with no emojis and a custom sign-off produces:

```text theme={"theme":{"light":"github-light","dark":"github-dark"}}
- Use a warm and approachable tone while remaining professional. Keep responses brief and focused on the essential information.
- Do not use emojis.
- End responses with "Thanks, Project ABC".
- Format dates as "Fri 16 May".
- Format times as "3pm".
```

<Note>
  These behaviour settings apply to the SMS channel only. Prompts are applied in this order: **SMS style prompt > Messaging channel behaviour > Agent behaviour**. Use the SMS style prompt for how the agent writes on SMS; use the Messaging channel behaviour prompt on the General tab for style shared across messaging channels. To change what the agent knows or does, edit the agent's behaviour on the Agent page.
</Note>

## Greeting

Set the opening message sent when an SMS conversation begins. The default is "Hello, how can I help?" and it overrides the default greeting configured on the General tab.

The field shows a live **character count** and **SMS segment count** as you type. A single SMS carries 160 GSM-7 characters; longer messages split into segments of 153 characters each, and each segment is billed as a message. Keeping your greeting to one segment keeps your cost per conversation down.

## From Draft to Live

1. Activate SMS in the **Channels** card on the **General** tab.
2. On the **SMS** tab, generate your SMS style prompt from the style options, or write your own. If you do not choose to edit the styling prompt, there is a default generic SMS styling prompt applied to your agent for SMS with the appropriate formatting. (Including character count per message)
3. Tailor the greeting, keeping an eye on the segment counter.
4. **Publish**.

Your agent is then live on SMS with SMS-specific style, while web chat and any other messaging channels keep their own configuration. One agent, one set of knowledge and logic, with per-channel style on top.