> ## Documentation Index
> Fetch the complete documentation index at: https://docs.fluents.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# In Call SMS

> Let the agent text the person while still on the phone with them, either freely worded or a message you fix in advance.

**In Call SMS** lets the agent send a text during the call. Useful for the things that
do not survive being read aloud, such as a link, an address or a booking reference.

***

## Set it up

On the agent's **Basic Information** tab, click **In Call SMS** under **Choose
Skills**. The dialog sets the phone number and the message policy.

First pick the **SMS number** the text is sent from. This comes from your numbers, so
you need one before the skill is usable.

Then choose a **Message policy**.

| Policy                        | What happens                                                            |
| ----------------------------- | ----------------------------------------------------------------------- |
| **Allow any SMS**             | The agent writes the text itself, based on what the conversation needs. |
| **Send a predefined message** | The agent sends exactly the message you write, every time.              |

Choosing **Send a predefined message** reveals a box for the message body.

***

## Fixed messages really are fixed

The agent is told it must not alter, add to or replace the wording, and the message is
enforced again when the text is actually sent. It cannot drift.

<Tip>
  Use a predefined message for anything with legal or brand wording you cannot let a
  model paraphrase. Use **Allow any SMS** when the useful content changes call to
  call.
</Tip>

A predefined message can include placeholders that are filled from the call's context,
so a fixed message can still carry a name or an order number.

***

## Limits

Messages are limited to **160 characters**. Write the predefined message to fit, and
expect the agent to keep free-written texts short.

The person's number is taken from the call, so the agent does not need to ask for it
on a phone call.

***

## Where to go next

* Send an email instead: **[In Call Email](./in-call-email)**
* Move the whole conversation to another number: **[Switch Communication](./switch-communication)**
* Everything else on the agent: **[Agents](/product/features/agent)**