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

# Send / Schedule Call

Hands the conversation over to a phone call — immediately, or scheduled — placed by one of your voice agents. This is the bridge between a chat agent and the [voice side](/agents/understanding-the-agent/introduction) of the platform.

<Note>
  WhatsApp agents only.
</Note>

## Fields

| Field                                     | Description                                                                                                                  |
| ----------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------- |
| **Function Name**                         | e.g. `schedule_call`                                                                                                         |
| **Description**                           | When to trigger or schedule a call — e.g. "Schedule a call when the user asks to speak with someone, or requests a callback" |
| **Calling Agent**                         | Which voice agent places the call. The agent tied to this WhatsApp number is marked *(default)*                              |
| **Calling Hours**                         | Start and end hour of the window in which a call may be placed                                                               |
| **If the call falls outside those hours** | `defer` or `cancel`                                                                                                          |
| **Workflow**                              | Optional. The workflow the call should run                                                                                   |

## Calling hours

**A call is never placed outside this window.** Times are in **Asia/Kolkata**, and the window applies both to immediate calls and to any time the AI schedules explicitly — so a customer asking for "a call at 11pm" cannot pull the agent outside your hours.

| Outside-hours behaviour                             | Result                                                |
| --------------------------------------------------- | ----------------------------------------------------- |
| **Move it to the next open window** (`defer`)       | The call happens at the start of the next open window |
| **Cancel the call — do not call at all** (`cancel`) | The call is dropped and nothing is dialled            |

Use `cancel` when a late call is worse than no call — a time-sensitive offer that will have expired by morning.

<Tip>
  Set the window to your actual business hours and leave it on `defer`. A callback that arrives next morning is useful; one that rings at midnight costs you the customer.
</Tip>

## Workflow

Optional. Leave it empty to reuse the workflow from this contact's last call. Setting one here always wins over that.

## Use in follow-ups

Add this function to the **Follow-Up Functions** list to let an unattended [follow-up](/chat-agents/configuration/follow-ups) place a call instead of sending a message. Setting **Follow-Up Action** to *Always schedule a call* requires such a function to exist.

## Related

<CardGroup cols={2}>
  <Card title="Voice agents" icon="phone-volume" href="/agents/understanding-the-agent/introduction">
    The agent that will actually make the call
  </Card>

  <Card title="Follow-ups" icon="clock" href="/chat-agents/configuration/follow-ups">
    Calling instead of messaging when someone goes quiet
  </Card>
</CardGroup>